1201
|
Kim HS, Kim TJ, Yoo YM. Melatonin combined with endoplasmic reticulum stress induces cell death via the PI3K/Akt/mTOR pathway in B16F10 melanoma cells. PLoS One 2014; 9:e92627. [PMID: 24647338 PMCID: PMC3960269 DOI: 10.1371/journal.pone.0092627] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/24/2014] [Indexed: 02/07/2023] Open
Abstract
This study investigated B16F10 melanoma cell death induced by melatonin combined with endoplasmic reticulum (ER) stress through the PI3K/Akt/mTOR pathway. Cell viability was significantly decreased after treatment with melatonin combined with ER stress from thapsigargin or tunicamycin compared to no treatment or treatment with melatonin only. Combined melatonin and ER stress also significantly reduced expression of p85β, p-Akt (Ser473, Thr308), and p-mTOR (Ser2448, Ser2481) compared to treatment with melatonin only. The ER stress protein p-PERK and p-eIF2α were significantly increased under combined melatonin and ER stress treatment compared to no treatment or treatment with melatonin only. Combined melatonin and ER stress significantly reduced Bcl-2 protein and augmented Bax protein compared to melatonin-only treatment. Also, the combined treatment significantly lowered expression of catalase, Cu/Zn-SOD, and Mn-SOD proteins compared to melatonin only. Expression of p85β was significantly more decreased under treatment with melatonin and thapsigargin or tunicamycin plus the PI3K inhibitors LY294002 or wortmannin than under treatment with only melatonin or a PI3K inhibitor. The PI3K downstream target p-Akt (Ser473, Thr308) showed significantly decreased expression under treatment with melatonin and thapsigargin or tunicamycin plus PI3K inhibitors than under treatment with melatonin or PI3K inhibitors only. These results indicate that survival of B16F10 melanoma cells after combined treatment with melatonin and ER stress inducers is suppressed through regulation of the PI3K/Akt/mTOR pathway. Melatonin combined with thapsigargin or tunicamycin appears to be a promising strategy for effective melanoma treatment.
Collapse
Affiliation(s)
- Han Sung Kim
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do, Republic of Korea
| | - Tack-Joong Kim
- Division of Biological Science and Technology, College of Science and Technology, Yonsei University, Wonju, Gangwon-do, Republic of Korea
| | - Yeong-Min Yoo
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do, Republic of Korea
- * E-mail:
| |
Collapse
|
1202
|
Rahman H, Qasim M, Oellerich M, Asif AR. Identification of the novel interacting partners of the mammalian target of rapamycin complex 1 in human CCRF-CEM and HEK293 cells. Int J Mol Sci 2014; 15:4823-36. [PMID: 24646917 PMCID: PMC3975426 DOI: 10.3390/ijms15034823] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/05/2014] [Accepted: 03/06/2014] [Indexed: 01/21/2023] Open
Abstract
The present study was undertaken to identify proteins that interact with the mammalian target of rapamycin complex 1 (mTORC1) to enable it to carry out its crucial cell signaling functions. Endogenous and myc-tag mTORC1 was purified, in-gel tryptic digested and then identified by nano-LC ESI Q-TOF MS/MS analysis. A total of nine novel interacting proteins were identified in both endogenous and myc-tag mTORC1 purifications. These new mTORC1 interacting partners include heterogeneous nuclear ribonucleoproteins A2/B1, enhancer of mRNA decapping protein 4, 60S acidic ribosomal protein, P0, nucleolin, dynamin 2, glyceraldehyde 3 phosphate dehydrogenase, 2-oxoglutarate dehydrogenase, glycosyl transferase 25 family member 1 and prohibitin 2. Furthermore hnRNP A2/B1 and dynamin 2 interaction with mTORC1 was confirmed on immunoblotting. The present study has for the first time identified novel interacting partners of mTORC1 in human T lymphoblasts (CCRF-CEM) and human embryonic kidney (HEK293) cells. These new interacting proteins may offer new targets for therapeutic interventions in human diseases caused by perturbed mTORC1 signaling.
Collapse
Affiliation(s)
- Hazir Rahman
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Centre, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Muhammad Qasim
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Centre, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Michael Oellerich
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Centre, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| | - Abdul R Asif
- Institute for Clinical Chemistry/UMG-Laboratories, University Medical Centre, Robert-Koch-Str. 40, Goettingen 37075, Germany.
| |
Collapse
|
1203
|
Abstract
MicroRNAs (miRNAs) play an important role in human tumorigenesis as oncogenes or tumor suppressors. miR-99a has been reported as a tumor suppressor gene in various cancers in humans. However, only limited information about the function of miR-99a in human breast cancers is available. Here we investigated the expression of miR-99a in breast cancer tissue specimens and its antitumor activity in breast cancer cells. We initially identified that the expression of miR-99a was significantly reduced in four breast cancer cell lines. More importantly, we found downregulation of miR-99a in breast cancer specimens from ten different patients. We then analyzed the mechanism of miR-99a in inhibiting tumorigenesis. Cell-based assays that showed overexpression of miR-99a not only reduced breast cancer cell viability by inducing accumulation of cells at sub-G1 phase and cell apoptosis, but also inhibited tumorigenicity in vivo. As a critical miR-99a target, we have shown that the function of mammalian target of rapamycin (mTOR) was greatly inhibited by miR-99a-based Luciferase report assay; overexpression of miR-99a reduced the expression of mTOR and its downstream phosphorylated proteins (p-4E-BP1 and p-S6K1). Similar to restoring miR-99a expression, mTOR downregulation suppressed cell viability and increased cell apoptosis, whereas restoration of mTOR expression significantly reversed the inhibitory effects of miR-99a on the mTOR/p-4E-BP1/p-S6K1 signal pathway and the miR-99a antitumor activity. In clinical specimens and cell lines, mTOR was commonly overexpressed and its protein levels were statistically inversely correlated with miR-99a expression. Taken together, these results have demonstrated that miR-99a antitumor activity is achieved by targeting the mTOR/p-4E-BP1/p-S6K1 pathway in human breast cancer cells. This study suggests a potential therapeutic strategy to effectively control breast cancer development.
Collapse
Affiliation(s)
- Yu Hu
- Department of Breast Surgery, Xiangya Hospital, Central South University, Changsha, China
| | - Qin Zhu
- Department of General Surgery, Xiangya Hospital, Central South University, Changsha, China
| | - Lili Tang
- Department of Breast Surgery, Xiangya Hospital, Central South University, Changsha, China
- * E-mail:
| |
Collapse
|
1204
|
Teng HF, Li PN, Hou DR, Liu SW, Lin CT, Loo MR, Kao CH, Lin KH, Chen SL. Valproic acid enhances Oct4 promoter activity through PI3K/Akt/mTOR pathway activated nuclear receptors. Mol Cell Endocrinol 2014; 383:147-58. [PMID: 24361750 DOI: 10.1016/j.mce.2013.12.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 11/24/2013] [Accepted: 12/13/2013] [Indexed: 12/21/2022]
Abstract
Valproic acid (VPA) has been shown to increase the reprogramming efficiency of induced pluripotent stem cells (iPSC) from somatic cells, but the mechanism by which VPA enhances iPSC induction has not been defined. Here we demonstrated that VPA directly activated Oct4 promoter activity through activation of the PI3K/Akt/mTOR signaling pathway that targeted the proximal hormone response element (HRE, -41∼-22) in this promoter. The activating effect of VPA is highly specific as similar compounds or constitutional isomers failed to instigate Oct4 promoter activity. We further demonstrated that the upstream 2 half-sites in this HRE were essential to the activating effect of VPA and they were targeted by a subset of nuclear receptors, such as COUP-TFII and TR2. These findings show the first time that NRs are implicated in the VPA stimulated expression of stem cell-specific factors and should invite more investigation on the cooperation between VPA and NRs on iPSC induction.
Collapse
Affiliation(s)
- Han Fang Teng
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan
| | - Pei Ning Li
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan
| | - Duen Ren Hou
- Department of Chemistry, National Central University, Jhongli 32001, Taiwan
| | - Sin Wei Liu
- Department of Chemistry, National Central University, Jhongli 32001, Taiwan
| | - Cheng Tao Lin
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan
| | - Moo Rung Loo
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan
| | - Chien Han Kao
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan
| | - Kwang Huei Lin
- Department of Biochemistry, Chang Gung University, Taoyuan 333, Taiwan
| | - Shen Liang Chen
- Department of Life Sciences, National Central University, Jhongli 32001, Taiwan.
| |
Collapse
|
1205
|
Berezhnoy A, Castro I, Levay A, Malek TR, Gilboa E. Aptamer-targeted inhibition of mTOR in T cells enhances antitumor immunity. J Clin Invest 2014; 124:188-97. [PMID: 24292708 DOI: 10.1172/jci69856] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 09/19/2013] [Indexed: 01/18/2023] Open
Abstract
Recent studies have underscored the importance of memory T cells in mediating protective immunity against pathogens and cancer. Pharmacological inhibition of regulators that mediate T cell differentiation promotes the differentiation of activated CD8(+) T cells into memory cells. Nonetheless, pharmacological agents have broad targets and can induce undesirable immunosuppressive effects. Here, we tested the hypothesis that aptamer-targeted siRNA inhibition of mTOR complex 1 (mTORC1) function in CD8(+) T cells can enhance their differentiation into memory T cells and potentiate antitumor immunity more effectively than the pharmacologic inhibitor rapamycin. To specifically target activated cells, we conjugated an siRNA targeting the mTORC1 component raptor to an aptamer that binds 4-1BB, a costimulatory molecule that is expressed on CD8(+) T cells following TCR stimulation. We found that systemic administration of the 4-1BB aptamer-raptor siRNA to mice downregulated mTORC1 activity in the majority of CD8(+) T cells, leading to the generation of a potent memory response that exhibited cytotoxic effector functions and enhanced vaccine-induced protective immunity in tumor-bearing mice. In contrast, while treatment with the general mTORC1 inhibitor rapamycin also enhanced antigen-activated CD8(+) T cell persistence, the cytotoxic effector functions of the reactivated memory cells were reduced and the alloreactivity of DCs was diminished. Consistent with the immunological findings, mice treated with rapamycin, but not with 4-1BB aptamer-raptor siRNA, failed to reject a subsequent tumor challenge.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Aptamers, Nucleotide/genetics
- CD8-Positive T-Lymphocytes/enzymology
- CD8-Positive T-Lymphocytes/immunology
- Cancer Vaccines/immunology
- Cell Proliferation
- Cells, Cultured
- Cytotoxicity, Immunologic
- Female
- Gene Knockdown Techniques
- Immunologic Memory
- Immunotherapy, Adoptive
- Mechanistic Target of Rapamycin Complex 1
- Melanoma, Experimental/immunology
- Melanoma, Experimental/therapy
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- Neoplasm Transplantation
- RNA, Small Interfering/genetics
- Regulatory-Associated Protein of mTOR
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
Collapse
|
1206
|
Li Z, Jiang J, Chen Y, You L, Huang Y, Tan A, Li Z, Jiang J, Niu B, Meng Z. PDP1 regulates energy metabolism through the IIS-TOR pathway in the red flour beetle, Tribolium castaneum. Arch Insect Biochem Physiol 2014; 85:127-136. [PMID: 24478036 DOI: 10.1002/arch.21146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The PAR-domain protein 1 (PDP1) is essential for locomotor activity of insects. However, its functions in insect growth and development have not been studied extensively, which prompted our hypothesis that PDP1 acts in energy metabolism. Here we report identification of TcPDP1 in the red flour beetle, Tribolium castaneum, and its functional analysis by RNAi. Treating larvae with dsTcPDP1 induced pupae developmental arrestment, accompanied by accelerated fat body degradation. dsTcPDP1 treatments in adults resulted in reduced female fecundity. Disruption of TcPDP1 expression affected the transcription of genes involved in insulin signaling transduction and mechanistic target of rapamycin (mTOR) pathway. These results support our hypothesis that TcPDP1 acts in energy metabolism in T. castaneum.
Collapse
Affiliation(s)
- Zhiqian Li
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
1207
|
Fant X, Durieu E, Chicanne G, Payrastre B, Sbrissa D, Shisheva A, Limanton E, Carreaux F, Bazureau JP, Meijer L. cdc-like/dual-specificity tyrosine phosphorylation-regulated kinases inhibitor leucettine L41 induces mTOR-dependent autophagy: implication for Alzheimer's disease. Mol Pharmacol 2014; 85:441-50. [PMID: 24366666 PMCID: PMC6067634 DOI: 10.1124/mol.113.090837] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 12/23/2013] [Indexed: 12/26/2022] Open
Abstract
Leucettines, a family of pharmacological inhibitors of dual-specificity tyrosine phosphorylation regulated kinases and cdc-like kinases (CLKs), are currently under investigation for their potential therapeutic application to Down syndrome and Alzheimer's disease. We here report that leucettine L41 triggers bona fide autophagy in osteosarcoma U-2 OS cells and immortalized mouse hippocampal HT22 cells, characterized by microtubule-associated protein light chain 3 membrane translocation and foci formation. Leucettine L41-triggered autophagy requires the Unc-51-like kinase and is sensitive to the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and 3-methyladenine, suggesting that it acts through the mammalian target of rapamycin (mTOR)/PI3K-dependent pathway. Leucettine L41 does not act by modifying the autophagic flux of vesicles. Leucettine L41-induced autophagy correlates best with inhibition of CLKs. Leucettine L41 modestly inhibited phosphatidylinositol-3-phosphate 5-kinase, FYVE domain-containing activity as tested both in vitro and in vivo, which may also contribute to autophagy induction. Altogether these results demonstrate that leucettines can activate the autophagic mTOR/PI3K pathway, a characteristic that may turn advantageous in the context of Alzheimer's disease treatment.
Collapse
Affiliation(s)
- Xavier Fant
- Centre National de la Recherche Scientifique (CNRS), USR3151, "Protein Phosphorylation and Human Disease," Station Biologique, Roscoff cedex, France (X.F., E.D.); Institut National de la Santé et de la Recherche Médicale/Université Paul Sabatier Unité Mixte de Recherche (UMR) 1048, "Production et fonctions plaquettaires: signalisation et phosphoinositides" group, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Toulouse cedex, France (G.C., B.P.); Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan (D.S., A.S.); Laboratoire Sciences Chimiques de Rennes, UMR CNRS 6226, Groupe Ingénierie Chimique et Molécules pour le Vivant (ICMV), Université de Rennes, Campus de Beaulieu, Rennes cedex, France (E.L., F.C., J.-P.B.); and ManRos Therapeutics, Perharidy Research Center, Roscoff, Bretagne, France (L.M.)
| | | | | | | | | | | | | | | | | | | |
Collapse
|
1208
|
Feng C, He K, Zhang C, Su S, Li B, Li Y, Duan CY, Chen S, Chen R, Liu Y, Li H, Wei M, Xia X, Dai R. JNK contributes to the tumorigenic potential of human cholangiocarcinoma cells through the mTOR pathway regulated GRP78 induction. PLoS One 2014; 9:e90388. [PMID: 24587347 PMCID: PMC3938720 DOI: 10.1371/journal.pone.0090388] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/28/2014] [Indexed: 12/14/2022] Open
Abstract
Less is known about the roles of c-Jun N-terminal kinase (JNK) in cholangiocarcinoma (CCA). Here, we report that JNK exerts its oncogenic action in human CCA cells, partially due to the mammalian target of rapamycin (mTOR) pathway regulated glucose-regulated protein 78 (GRP78) induction. In human CCA cells, the phosphorylation of eukaryotic initiation factor alpha (eIF2α) results in the accumulation of activating transcription factor 4 (ATF4) and GRP78 independent of unfolded protein response (UPR). Suppression of GRP78 expression decreases the proliferation and invasion of human CCA cells. It's notable that mTOR is required for eIF2α phosphorylation-induced ATF4 and GRP78 expression. Importantly, JNK promotes eIF2α/ATF4-mediated GRP78 induction through regulating the activity of mTOR. Thus, our study implicates JNK/mTOR signaling plays an important role in cholangiocarcinogenesis, partially through promoting the eIF2α/ATF4/GRP78 pathway.
Collapse
Affiliation(s)
- Chunhong Feng
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
| | - Kai He
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
| | - Chunyan Zhang
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Song Su
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
| | - Bo Li
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
| | - Yuxiao Li
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Chun-Yan Duan
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Shaokun Chen
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Run Chen
- Department of Public Health, Luzhou Medical College, Luzhou, Sichuan, China
| | - Youping Liu
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Hong Li
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
| | - Mei Wei
- Affiliated Hospital of Chinese Traditional Medicine, Luzhou Medical College, Luzhou, Sichuan, China
| | - Xianming Xia
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
- * E-mail: (XMX); (RYD)
| | - Rongyang Dai
- Department of Hepatobiliary Surgery of the Affiliated Hospital, Luzhou Medical College, Luzhou, Sichuan, China
- Department of Biochemistry and Molecular Biology, Luzhou Medical College, Luzhou, Sichuan, China
- * E-mail: (XMX); (RYD)
| |
Collapse
|
1209
|
Ahmed M, Hussain AR, Bavi P, Ahmed SO, Al Sobhi SS, Al-Dayel F, Uddin S, Al-Kuraya KS. High prevalence of mTOR complex activity can be targeted using Torin2 in papillary thyroid carcinoma. Carcinogenesis 2014; 35:1564-72. [PMID: 24583924 DOI: 10.1093/carcin/bgu051] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) signaling cascade is a key regulatory pathway controlling initiation of messenger RNA in mammalian cells. Although dysregulation of mTOR signaling has been reported earlier in cancers, there is paucity of data about mTOR expression in papillary thyroid carcinoma (PTC). Therefore, in this study, we investigated the presence of mTORC2 and mTORC1 complexes in a large cohort of >500 PTC samples. Our clinical data showed the presence of active mTORC1 and mTORC2 in 81 and 39% of PTC samples, respectively. Interestingly, coexpression of mTORC1 and mTORC2 activity was seen in a 32.5% (164/504) of the PTC studied and this association was statistically significant (P = 0.0244). mTOR signaling complex was also found to be associated with activated AKT and 4E-BP1. In vitro, using Torin2, a second-generation mTOR inhibitor or gene silencing of mTOR expression prevented mTORC1 and mTORC2 activity leading to inactivation of P70S6, 4E-BP1, AKT and Bad. Inhibition of mTOR activity led to downregulation of cyclin D1, a gene regulated by messenger RNA translation via phosphorylation of 4E-BP1. Torin2 treatment also inhibited cell viability and induced caspase-dependent apoptosis via activation of mitochondrial apoptotic pathway in PTC cells. Finally, Torin2 treatment induces anticancer effect on PTC xenograft tumor growth in nude mice via inhibition of mTORC1 and mTORC2 and its associated pathways. Our results suggest that coexpression of mTORC1 and mTORC2 is seen frequently in the clinical PTC samples and dual targeting of mTORC1 and mTORC2 activity may be an attractive therapeutic target for treatment of PTC.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Adenocarcinoma, Follicular/drug therapy
- Adenocarcinoma, Follicular/metabolism
- Adenocarcinoma, Follicular/pathology
- Animals
- Apoptosis/drug effects
- Blotting, Western
- Carcinoma, Papillary/drug therapy
- Carcinoma, Papillary/metabolism
- Carcinoma, Papillary/pathology
- Caspases/metabolism
- Cell Cycle/drug effects
- Cell Cycle Proteins
- Cell Proliferation/drug effects
- Cohort Studies
- Female
- Humans
- Immunoenzyme Techniques
- Male
- Mechanistic Target of Rapamycin Complex 1
- Mechanistic Target of Rapamycin Complex 2
- Mice
- Mice, Nude
- Middle Aged
- Mitochondria/drug effects
- Mitochondria/metabolism
- Multiprotein Complexes/metabolism
- Naphthyridines/pharmacology
- Neoplasm Staging
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphoproteins/metabolism
- Phosphorylation
- Prognosis
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Small Interfering/genetics
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Thyroid Neoplasms/drug therapy
- Thyroid Neoplasms/metabolism
- Thyroid Neoplasms/pathology
- Tissue Array Analysis
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
Collapse
Affiliation(s)
| | | | | | | | | | - Fouad Al-Dayel
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia and
| | | | - Khawla S Al-Kuraya
- Human Cancer Genomic Research, Department of Life Science, College of Science and College of Medicine, Al-Faisal University, Riyadh 11533, Saudi Arabia
| |
Collapse
|
1210
|
Poncet N, Mitchell FE, Ibrahim AFM, McGuire VA, English G, Arthur JSC, Shi YB, Taylor PM. The catalytic subunit of the system L1 amino acid transporter (slc7a5) facilitates nutrient signalling in mouse skeletal muscle. PLoS One 2014; 9:e89547. [PMID: 24586861 PMCID: PMC3935884 DOI: 10.1371/journal.pone.0089547] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 01/22/2014] [Indexed: 01/13/2023] Open
Abstract
The System L1-type amino acid transporter mediates transport of large neutral amino acids (LNAA) in many mammalian cell-types. LNAA such as leucine are required for full activation of the mTOR-S6K signalling pathway promoting protein synthesis and cell growth. The SLC7A5 (LAT1) catalytic subunit of high-affinity System L1 functions as a glycoprotein-associated heterodimer with the multifunctional protein SLC3A2 (CD98). We generated a floxed Slc7a5 mouse strain which, when crossed with mice expressing Cre driven by a global promoter, produced Slc7a5 heterozygous knockout (Slc7a5+/−) animals with no overt phenotype, although homozygous global knockout of Slc7a5 was embryonically lethal. Muscle-specific (MCK Cre-mediated) Slc7a5 knockout (MS-Slc7a5-KO) mice were used to study the role of intracellular LNAA delivery by the SLC7A5 transporter for mTOR-S6K pathway activation in skeletal muscle. Activation of muscle mTOR-S6K (Thr389 phosphorylation) in vivo by intraperitoneal leucine injection was blunted in homozygous MS-Slc7a5-KO mice relative to wild-type animals. Dietary intake and growth rate were similar for MS-Slc7a5-KO mice and wild-type littermates fed for 10 weeks (to age 120 days) with diets containing 10%, 20% or 30% of protein. In MS-Slc7a5-KO mice, Leu and Ile concentrations in gastrocnemius muscle were reduced by ∼40% as dietary protein content was reduced from 30 to 10%. These changes were associated with >50% decrease in S6K Thr389 phosphorylation in muscles from MS-Slc7a5-KO mice, indicating reduced mTOR-S6K pathway activation, despite no significant differences in lean tissue mass between groups on the same diet. MS-Slc7a5-KO mice on 30% protein diet exhibited mild insulin resistance (e.g. reduced glucose clearance, larger gonadal adipose depots) relative to control animals. Thus, SLC7A5 modulates LNAA-dependent muscle mTOR-S6K signalling in mice, although it appears non-essential (or is sufficiently compensated by e.g. SLC7A8 (LAT2)) for maintenance of normal muscle mass.
Collapse
Affiliation(s)
- Nadège Poncet
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fiona E. Mitchell
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- Section on Molecular Morphogenesis, Program in Cellular Regulation and Metabolism (PCRM), NICHD, NIH, Bethesda, Maryland, United States of America
| | - Adel F. M. Ibrahim
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Victoria A. McGuire
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Grant English
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - J. Simon C Arthur
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Yun-Bo Shi
- Section on Molecular Morphogenesis, Program in Cellular Regulation and Metabolism (PCRM), NICHD, NIH, Bethesda, Maryland, United States of America
- * E-mail: (Y-BS); (PMT)
| | - Peter M. Taylor
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (Y-BS); (PMT)
| |
Collapse
|
1211
|
Bertoldo F, Silvestris F, Ibrahim T, Cognetti F, Generali D, Ripamonti CI, Amadori D, Colleoni MA, Conte P, Del Mastro L, De Placido S, Ortega C, Santini D. Targeting bone metastatic cancer: Role of the mTOR pathway. Biochim Biophys Acta Rev Cancer 2014; 1845:248-54. [PMID: 24508774 DOI: 10.1016/j.bbcan.2014.01.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 01/22/2014] [Accepted: 01/28/2014] [Indexed: 12/14/2022]
Abstract
One of the great challenges of cancer medicine is to develop effective treatments for bone metastatic cancer. Most patients with advanced solid tumors will develop bone metastasis and will suffer from skeletal related events associated with this disease. Although some therapies are available to manage symptoms derived from bone metastases, an effective treatment has not been developed yet. The mammalian target of rapamycin (mTOR) pathway regulates cell growth and survival. Alterations in mTOR signaling have been associated with pathological malignancies, including bone metastatic cancer. Inhibition of mTOR signaling might therefore be a promising alternative for bone metastatic cancer management. This review summarizes the current knowledge on mTOR pathway signaling in bone tissue and provides an overview on the known effects of mTOR inhibition in bone cancer, both in in vitro and in vivo models.
Collapse
Affiliation(s)
| | - Franco Silvestris
- Department of Biomedical Sciences and Human Oncology, Section of Clinical Oncology, University of Bari 'A. Moro', Bari, Italy
| | - Toni Ibrahim
- Osteoncology and Rare Tumors Center, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy
| | | | - Daniele Generali
- UO Multidisciplinare di Patologia Mammaria, US Terapia Molecolare e Farmacogenomica, AZ. Istituti Ospitalieri di Cremona, Cremona, Italy
| | - Carla Ida Ripamonti
- Supportive Care in Cancer Unit, Department of Hematology and Pediatric Onco-Hematology, Fondazione IRCCS, Istituto Nazionale dei Tumori, Milan, Italy
| | - Dino Amadori
- Osteoncology and Rare Tumors Center, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Meldola, Italy
| | | | - Pierfranco Conte
- Oncologia Medica 2, Istituto Oncologico Veneto IRCCS, Padova, Italy
| | - Lucia Del Mastro
- UO Sviluppo Terapie Innovative, IRCCS AOU San Martino, IST, National Institute for Cancer Research, Genoa, Italy
| | - Sabino De Placido
- Department of Endocrinology and Molecular and Clinical Oncology, University of Naples Federico II, Naples, Italy
| | | | - Daniele Santini
- Department of Medical Oncology, University Campus Bio-Medico, Rome, Italy.
| |
Collapse
|
1212
|
Abstract
Gastric cancer is the second most common cause of cancer death worldwide. Recent development of targeted agents provides clinicians with additional systemic treatment options to conventional cytotoxic agents. Predictive markers are undoubtedly important for guiding the appropriate use of targeted and cytotoxic agents. Currently, however, HER2 is the only predictive biomarker validated for gastric cancer. In this review, candidate predictive markers for response to other targeted agents and cytotoxic chemotherapeutic agents are discussed.
Collapse
Affiliation(s)
- Hark Kyun Kim
- Center for Gastric Cancer, National Cancer Center, Goyang, 410-769, Republic of Korea.
| | | |
Collapse
|
1213
|
Wheeler DE, Buck NA, Evans JD. Expression of insulin/insulin-like signalling and TOR pathway genes in honey bee caste determination. Insect Mol Biol 2014; 23:113-121. [PMID: 24224645 DOI: 10.1111/imb.12065] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The development of queen and worker castes in honey bees is induced by differential nutrition, with future queens and workers receiving diets that are qualitatively and quantitatively different. We monitored the gene expression of 14 genes for components of the insulin/insulin-like signalling and TOR pathways in honey bee larvae from 40-88 h after hatching. We compared normally fed queen and normally fed worker larvae and found that three genes showed expression differences in 40-h-old larvae. Genes that show such early differences in expression may be part of the mechanism that transduces nutrition level into a hormone signal. We then compared changes in expression after shifts in diet with those in normally developing queens and workers. Following a shift to the worker diet, the expression of 9/14 genes was upregulated in comparison with queens. Following a shift to the queen diet, expression of only one gene changed. The honey bee responses may function together as a homeostatic mechanism buffering larvae from caste-disrupting variation in nutrition. The different responses would be part of the canalization of both the queen and worker developmental pathways, and as such, a signature of advanced sociality.
Collapse
Affiliation(s)
- D E Wheeler
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | | | | |
Collapse
|
1214
|
Chen J, Tu X, Esen E, Joeng KS, Lin C, Arbeit JM, Rüegg MA, Hall MN, Ma L, Long F. WNT7B promotes bone formation in part through mTORC1. PLoS Genet 2014; 10:e1004145. [PMID: 24497849 PMCID: PMC3907335 DOI: 10.1371/journal.pgen.1004145] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 12/12/2013] [Indexed: 11/30/2022] Open
Abstract
WNT signaling has been implicated in both embryonic and postnatal bone formation. However, the pertinent WNT ligands and their downstream signaling mechanisms are not well understood. To investigate the osteogenic capacity of WNT7B and WNT5A, both normally expressed in the developing bone, we engineered mouse strains to express either protein in a Cre-dependent manner. Targeted induction of WNT7B, but not WNT5A, in the osteoblast lineage dramatically enhanced bone mass due to increased osteoblast number and activity; this phenotype began in the late-stage embryo and intensified postnatally. Similarly, postnatal induction of WNT7B in Runx2-lineage cells greatly stimulated bone formation. WNT7B activated mTORC1 through PI3K-AKT signaling. Genetic disruption of mTORC1 signaling by deleting Raptor in the osteoblast lineage alleviated the WNT7B-induced high-bone-mass phenotype. Thus, WNT7B promotes bone formation in part through mTORC1 activation. The human bone tissue is of considerable regenerative capacity as reflected in bone remodeling and in fracture healing. However, bone tissue regeneration deteriorates with age, and tremendous unmet medical needs exist for safe and effective strategies to stimulate bone formation in older individuals commonly inflicted with osteoporosis or osteopenia. WNT signaling has emerged as a promising target pathway for developing novel bone anabolic therapeutics. Identifying bone-promoting WNT ligands and elucidating the underlying mechanisms may lead to useful therapeutic targets. The present study reports that WNT7B potently enhances bone formation through activation of mTORC1 in the mouse.
Collapse
Affiliation(s)
- Jianquan Chen
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Xiaolin Tu
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Emel Esen
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Kyu Sang Joeng
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Congxin Lin
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jeffrey M. Arbeit
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | | | | | - Liang Ma
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Fanxin Long
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
| |
Collapse
|
1215
|
Ren XS, Sato Y, Harada K, Sasaki M, Furubo S, Song JY, Nakanuma Y. Activation of the PI3K/mTOR pathway is involved in cystic proliferation of cholangiocytes of the PCK rat. PLoS One 2014; 9:e87660. [PMID: 24498161 PMCID: PMC3907540 DOI: 10.1371/journal.pone.0087660] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 12/28/2013] [Indexed: 12/13/2022] Open
Abstract
The polycystic kidney (PCK) rat is an animal model of Caroli’s disease as well as autosomal recessive polycystic kidney disease (ARPKD). The signaling pathways involving the mammalian target of rapamycin (mTOR) are aberrantly activated in ARPKD. This study investigated the effects of inhibitors for the cell signaling pathways including mTOR on cholangiocyte proliferation of the PCK rat. Cultured PCK cholangiocytes were treated with rapamycin and everolimus [inhibitors of mTOR complex 1 (mTOC1)], LY294002 [an inhibitor of phosphatidylinositol 3-kinase (PI3K)] and NVP-BEZ235 (an inhibitor of PI3K and mTORC1/2), and the cell proliferative activity was determined in relation to autophagy and apoptosis. The expression of phosphorylated (p)-mTOR, p-Akt, and PI3K was increased in PCK cholangiocytes compared to normal cholangiocytes. All inhibitors significantly inhibited the cell proliferative activity of PCK cholangiocytes, where NVP-BEZ235 had the most prominent effect. NVP-BEZ235, but not rapamycin and everolimus, further inhibited biliary cyst formation in the three-dimensional cell culture system. Rapamycin and everolimus induced apoptosis in PCK cholangiocytes, whereas NVP-BEZ235 inhibited cholangiocyte apoptosis. Notably, the autophagic response was significantly induced following the treatment with NVP-BEZ235, but not rapamycin and everolimus. Inhibition of autophagy using siRNA against protein-light chain3 and 3-methyladenine significantly increased the cell proliferative activity of PCK cholangiocytes treated with NVP-BEZ235. In vivo, treatment of the PCK rat with NVP-BEZ235 attenuated cystic dilatation of the intrahepatic bile ducts, whereas renal cyst development was unaffected. These results suggest that the aberrant activation of the PI3K/mTOR pathway is involved in cystic proliferation of cholangiocytes of the PCK rat, and inhibition of the pathway can reduce cholangiocyte proliferation via the mechanism involving apoptosis and/or autophagy.
Collapse
Affiliation(s)
- Xiang Shan Ren
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
- Department of Pathology, Yanbian University College of Medicine, Yanji-city, China
| | - Yasunori Sato
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Kenichi Harada
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Motoko Sasaki
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Shinichi Furubo
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Jing Yu Song
- Department of Pathology, Yanbian University College of Medicine, Yanji-city, China
| | - Yasuni Nakanuma
- Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
- Department of Pathology, Shizuoka Cancer Center, Shizuoka, Japan
- * E-mail:
| |
Collapse
|
1216
|
Zardavas D, Phillips WA, Loi S. PIK3CA mutations in breast cancer: reconciling findings from preclinical and clinical data. Breast Cancer Res 2014; 16:201. [PMID: 25192370 PMCID: PMC4054885 DOI: 10.1186/bcr3605] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 01/23/2014] [Indexed: 02/08/2023] Open
Abstract
PIK3CA mutations represent one of the most common genetic aberrations in breast cancer. They have been reported to be present in over one-third of cases, with enrichment in the luminal and in human epidermal growth factor receptor 2-positive subtypes. Substantial preclinical data on the oncogenic properties of these mutations have been reported. However, whilst the preclinical data have clearly shown an association with robust activation of the pathway and resistance to common therapies used in breast cancer, the clinical data reported up to now do not support that the PIK3CA mutated genotype is associated with high levels of pathway activation or with a poor prognosis. We speculate that this may be due to the minimal use of transgenic mice models thus far. In this review, we discuss both the preclinical and clinical data associated with PIK3CA mutations and their potential implications. Prospective clinical trials stratifying by PIK3CA genotype will be necessary to determine if the mutation also predicts for increased sensitivity to agents targeting the phosphoinositide 3-kinase pathway.
Collapse
Affiliation(s)
| | - Wayne A Phillips
- Surgical Oncology Research Laboratory, Peter MacCallum Cancer Centre, Melbourne,
Victoria 3002, Australia
- Division of Cancer Medicine and Research, Peter MacCallum Cancer Centre, St
Andrews Place, East Melbourne, Victoria 3002, Australia
| | - Sherene Loi
- Division of Cancer Medicine and Research, Peter MacCallum Cancer Centre, St
Andrews Place, East Melbourne, Victoria 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville,
Victoria 3002, Australia
| |
Collapse
|
1217
|
Robles-Molina E, Dionisio-Vicuña M, Guzmán-Hernández ML, Reyes-Cruz G, Vázquez-Prado J. Gβγ interacts with mTOR and promotes its activation. Biochem Biophys Res Commun 2014; 444:218-23. [PMID: 24462769 DOI: 10.1016/j.bbrc.2014.01.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 01/14/2014] [Indexed: 01/09/2023]
Abstract
Diverse G protein-coupled receptors depend on Gβγ heterodimers to promote cell polarization and survival via direct activation of PI3Kγ and potentially other effectors. These events involve full activation of AKT via its phosphorylation at Ser473, suggesting that mTORC2, the kinase that phosphorylates AKT at Ser473, is activated downstream of Gβγ. Thus, we tested the hypothesis that Gβγ directly contributes to mTOR signaling. Here, we demonstrate that endogenous mTOR interacts with Gβγ. Cell stimulation with serum modulates Gβγ interaction with mTOR. The carboxyl terminal region of mTOR, expressed as a GST-fusion protein, including the serine/threonine kinase domain, binds Gβγ heterodimers containing different Gβ subunits, except Gβ4. Both, mTORC1 and mTORC2 complexes interact with Gβ₁γ₂ which promotes phosphorylation of their respective substrates, p70S6K and AKT. In addition, chronic treatment with rapamycin, a condition known to interfere with assembly of mTORC2, reduces the interaction between Gβγ and mTOR and the phosphorylation of AKT; whereas overexpression of Gαi interfered with the effect of Gβγ as promoter of p70S6K and AKT phosphorylation. Altogether, our results suggest that Gβγ positively regulates mTOR signaling via direct interactions and provide further support to emerging strategies based on the therapeutical potential of inhibiting different Gβγ signaling interfaces.
Collapse
Affiliation(s)
- Evelyn Robles-Molina
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Apartado postal 14-740, México, D.F. 07360, Mexico
| | - Misael Dionisio-Vicuña
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Apartado postal 14-740, México, D.F. 07360, Mexico
| | - María Luisa Guzmán-Hernández
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Apartado postal 14-740, México, D.F. 07360, Mexico
| | - Guadalupe Reyes-Cruz
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Apartado postal 14-740, México, D.F. 07360, Mexico
| | - José Vázquez-Prado
- Department of Pharmacology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Apartado postal 14-740, México, D.F. 07360, Mexico.
| |
Collapse
|
1218
|
Cirone P, Andresen CJ, Eswaraka JR, Lappin PB, Bagi CM. Patient-derived xenografts reveal limits to PI3K/mTOR- and MEK-mediated inhibition of bladder cancer. Cancer Chemother Pharmacol 2014; 73:525-38. [PMID: 24442130 DOI: 10.1007/s00280-014-2376-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/06/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Metastatic bladder cancer is a serious condition with a 5-year survival rate of approximately 14 %, a rate that has remained unchanged for almost three decades. Thus, there is a profound need to identify the driving mutations for these aggressive tumors to better determine appropriate treatments. Mutational analyses of clinical samples suggest that mutations in either the phosphoinositide-3 kinase (PI3K)-AKT-mammalian target of rapamycin (mTOR) or RAS/MEK/ERK pathways drive bladder cancer progression, although it remains to be tested whether the inhibition of either (or both) of these pathways can arrest PI3K/mTOR- or Ras-driven proliferation. METHODS Herein, we used several bladder cancer cell lines to determine drug sensitivity according to genetic background and also studied mouse models of engrafted UM-UC-3 cells and patient-derived xenografts (PDXs) to test PI3K/mTOR and MEK inhibition in vivo. RESULTS Inhibition of these pathways utilizing PF-04691502, a PI3K and mTOR inhibitor, and PD-0325901, a MEK inhibitor, slowed the tumor growth of PDX models of bladder cancer. The growth inhibitory effect of combination therapy was similar to that of the clinical maximum dose of cisplatin; mechanistically, this appeared to predominantly occur via drug-induced cytostatic growth inhibition as well as diminished vascular endothelial growth factor secretion in the tumor models. Kinase arrays of tumors harvested after treatment demonstrated activated p53 and Axl as well as STAT1 and STAT3. CONCLUSION Taken together, these results indicate that clinically relevant doses of PF-04691502 and PD-0325901 can suppress bladder tumor growth in PDX models, thus offering additional potential treatment options by a precision medicine approach.
Collapse
|
1219
|
Pereira MG, Baptista IL, Carlassara EOC, Moriscot AS, Aoki MS, Miyabara EH. Leucine supplementation improves skeletal muscle regeneration after cryolesion in rats. PLoS One 2014; 9:e85283. [PMID: 24416379 PMCID: PMC3885703 DOI: 10.1371/journal.pone.0085283] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 11/25/2013] [Indexed: 12/31/2022] Open
Abstract
This study was undertaken in order to provide further insight into the role of leucine supplementation in the skeletal muscle regeneration process, focusing on myofiber size and strength recovery. Young (2-month-old) rats were subjected or not to leucine supplementation (1.35 g/kg per day) started 3 days prior to cryolesion. Then, soleus muscles were cryolesioned and continued receiving leucine supplementation until 1, 3 and 10 days later. Soleus muscles from leucine-supplemented animals displayed an increase in myofiber size and a reduction in collagen type III expression on post-cryolesion day 10. Leucine was also effective in reducing FOXO3a activation and ubiquitinated protein accumulation in muscles at post-cryolesion days 3 and 10. In addition, leucine supplementation minimized the cryolesion-induced decrease in tetanic strength and increase in fatigue in regenerating muscles at post-cryolesion day 10. These beneficial effects of leucine were not accompanied by activation of any elements of the phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin signalling pathway in the regenerating muscles. Our results show that leucine improves myofiber size gain and strength recovery in regenerating soleus muscles through attenuation of protein ubiquitination. In addition, leucine might have therapeutic effects for muscle recovery following injury and in some muscle diseases.
Collapse
Affiliation(s)
- Marcelo G. Pereira
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Igor L. Baptista
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Eduardo O. C. Carlassara
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Anselmo S. Moriscot
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Marcelo S. Aoki
- School of Arts, Sciences and Humanities, University of Sao Paulo, Sao Paulo, Brazil
| | - Elen H. Miyabara
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
- * E-mail:
| |
Collapse
|
1220
|
Foster HA, Davies J, Pink RC, Turkcigdem S, Goumenou A, Carter DR, Saunders NJ, Thomas P, Karteris E. The human myometrium differentially expresses mTOR signalling components before and during pregnancy: evidence for regulation by progesterone. J Steroid Biochem Mol Biol 2014; 139:166-72. [PMID: 23541542 PMCID: PMC3855612 DOI: 10.1016/j.jsbmb.2013.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 02/07/2013] [Accepted: 02/24/2013] [Indexed: 10/27/2022]
Abstract
Emerging studies implicate the signalling of the mammalian target of rapamycin (mTOR) in a number of reproductive functions. To this date, there are no data regarding the expression of mTOR signalling components in the human myometrium during pregnancy. We hypothesized that mTOR-related genes might be differentially expressed in term or preterm labour as well as in labour or non-labour myometria during pregnancy. Using quantitative RT-PCR we demonstrate for first time that there is a significant downregulation of mTOR, DEPTOR, and Raptor in preterm labouring myometria when compared to non-pregnant tissues taken from the same area (lower segment). We used an immortalized myometrial cell line (ULTR) as an in vitro model to dissect further mTOR signalling. In ULTR cells DEPTOR and Rictor had a cytoplasmic distribution, whereas mTOR and Raptor were detected in the cytoplasm and the nucleus, indicative of mTORC1 shuttling. Treatment with inflammatory cytokines caused only minor changes in gene expression of these components, whereas progesterone caused significant down-regulation. We performed a non-biased gene expression analysis of ULTR cells using Nimblegen human gene expression microarray (n=3), and selected genes were validated by quantitative RT-PCR in progesterone treated myometrial cells. Progesterone significantly down-regulated key components of the mTOR pathway. We conclude that the human myometrium differentially expresses mTOR signalling components and they can be regulated by progesterone. This article is part of a Special Issue entitled 'Pregnancy and Steroids'.
Collapse
Affiliation(s)
- Helen A Foster
- Biosciences, Centre for Cell and Chromosome Biology, Brunel University, Uxbridge UB8 3PH, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
1221
|
Pupyshev AB. [Reparative autophagy and autophagy death of cells. Functional and regulatory aspects]. Tsitologiia 2014; 56:179-196. [PMID: 25509414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molecular regulation of reparative/homeostatic autophagy induced by failure of vital resources and by cellular stress is considered. Extensive autophagy regulatory apparatus responds to starvation, insufficiency of growth factors and energy supply, accumulation of unfolded proteins (ER stress), reactive oxygen species, microbial invasion. Central sensor of the regulation is kinase mTOR. Part of the mTOR pool presented in lysosomes responds to the local level of amino acids and is able to induce autophagy under low rates of intralysosomal proteolysis. Autophagy is a self-regulated cell process, the peak of autophagy is followed by its regulatory weakening by amino acids formed in autophagolysosomes. Protective effect of autophagy is associated mainly with removal of permeabilized mitochondria generating ROS, and elimination of abnormally folded proteins. Autophagy has optimum of its activity: its deficiency leads to accelerated cellular aging, and the excessive autophagy brings to the deficiency of cellular survival resources and cell death. Autophagy cell death seems like a hyper-stimulated self-eating of the cell, but more probably that excessive autophagy disturbs cellular energy supply and switches on some specific cell death signalization (possibly associated with kinases c-Jun, DRP-1, PI3K class I etc.). Some approaches to use reparative autophagy for prevention of cell degeneration are considered.
Collapse
|
1222
|
Fatkhullina AR, Abramov SN, Skibo IV, Abramova ZI. [Dexamethasone affect on the expression of bcl-2 and mTOR genes in T-lymphocytes from healthy donors]. Tsitologiia 2014; 56:459-461. [PMID: 25696988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Synthetic glucocorticoids are able to activate apoptosis in the cells by regulating the transcription of the respective genes. Effect of dexamethasone on apoptosis is an established fact. However, its influence on another program of cell death autophagy, is currently unproven. Therefore, in this paper we have analyzed the influence of dexamethasone on the expression of bcl-2 and mTOR genes in T-lymphocytes from healthy donors. The results showed that dexamethasone reduced the expression of bcl-2 and mTOR genes. However, the nature of the effect of dexamethasone on mTOR and bcl-2 expression was different: the expression of bcl-2 gene in the long-term cultivation was maintained at the same reduced level, while the expression of mTOR was first reduced and then increased.
Collapse
|
1223
|
Khapre RV, Kondratova AA, Patel S, Dubrovsky Y, Wrobel M, Antoch MP, Kondratov RV. BMAL1-dependent regulation of the mTOR signaling pathway delays aging. Aging (Albany NY) 2014; 6:48-57. [PMID: 24481314 PMCID: PMC3927809 DOI: 10.18632/aging.100633] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 01/28/2014] [Indexed: 01/11/2023]
Abstract
The circadian clock, an internal time-keeping system, has been linked with control of aging, but molecular mechanisms of regulation are not known. BMAL1 is a transcriptional factor and core component of the circadian clock; BMAL1 deficiency is associated with premature aging and reduced lifespan. Here we report that activity of mammalian Target of Rapamycin Complex 1 (mTORC1) is increased upon BMAL1 deficiency both in vivo and in cell culture. Increased mTOR signaling is associated with accelerated aging; in accordance with that, treatment with the mTORC1 inhibitor rapamycin increased lifespan of Bmal1-/- mice by 50%. Our data suggest that BMAL1 is a negative regulator of mTORC1 signaling. We propose that the circadian clock controls the activity of the mTOR pathway through BMAL1-dependent mechanisms and this regulation is important for control of aging and metabolism.
Collapse
Affiliation(s)
- Rohini V. Khapre
- Center for Gene Regulation in Health and Diseases, BGES, Cleveland State University, Cleveland, OH
| | | | - Sonal Patel
- Center for Gene Regulation in Health and Diseases, BGES, Cleveland State University, Cleveland, OH
| | - Yuliya Dubrovsky
- Center for Gene Regulation in Health and Diseases, BGES, Cleveland State University, Cleveland, OH
| | - Michelle Wrobel
- Tartis Aging, Inc, 640 Ellicott Street, Ste. 444, Buffalo, NY 14203-
| | - Marina P. Antoch
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263
| | - Roman V. Kondratov
- Center for Gene Regulation in Health and Diseases, BGES, Cleveland State University, Cleveland, OH
| |
Collapse
|
1224
|
Abstract
This review focuses on anabolic signaling pathways through which insulin, amino acids, and resistance exercise act to regulate the protein kinase complex referred to as mechanistic target of rapamycin complex (mTORC) 1. Initially, individual pathways through which the 3 anabolic signals act to modulate mTORC1 signaling will be discussed, followed by a summation of evidence showing an additive effect of the regulators. The emphasis will be on mTORC1 signaling in skeletal muscle and its contribution to modulation of rates of protein synthesis. In addition, results from studies using cells in culture will be used to provide a more complete picture of the molecular details of the individual pathways.
Collapse
Affiliation(s)
- Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA
| |
Collapse
|
1225
|
Kochetkova EI, Bykova TV, Zubova SG, Pospelova TV. [Role of MEK/ERK pathway in the regulation of HDACI-induced senescence of transformed rat embryo fibroblasts]. Tsitologiia 2014; 56:581-590. [PMID: 25697003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A key regulator of cellular senescence, mTORC1 complex, is the target of many signaling cascades including Ras/Raf/MEK/ERK-signaling cascade. In this paper we investigated the role of MEK/ERK-branch of this cascade in the process of cellular senescence induced by histone deacetylase inhibitor (HDACI) sodium butyrate (NaBut), in transformed rat embryo fibroblasts. Suppression of MEK/ERK activity by inhibitor PD0325901 does not prevent activation of mTORC1 complex induced by NaBut treatment. After the suppression of MEK/ERK, activity of mTORC1 increased as well as complex mTORC2. Activation of mTOR-containing complexes accompanied by the reorganization of the actin cytoskeleton with the formation of actin stress fibers and the appearance of some markers of cellular senescence. In contrast to NaBut-induced senescence accumulation of proteins was not observed, which may be due to increased activity of the degradation processes. Furthermore, the induction of senescence in conditions suppressed MEK/ERK leads to a drastic decrease in cell viability. Thus, NaBut-induced senescence upon suppressed activity of MEK/ERK-branch of MAP kinase cascade has a more pronounced tumor-suppressor effect associated with stronger activation of both mTOR-complexes, reorganization of the actin cytoskeleton and protein degradation.
Collapse
|
1226
|
Marcq I, Nyga R, Cartier F, Amrathlal RS, Ossart C, Ouled-Haddou H, Ghamlouch H, Galmiche A, Chatelain D, Lamotte L, Debuysscher V, Fuentes V, Nguyen-Khac E, Regimbeau JM, Marolleau JP, Latour S, Bouhlal H. Identification of SLAMF3 (CD229) as an inhibitor of hepatocellular carcinoma cell proliferation and tumour progression. PLoS One 2013; 8:e82918. [PMID: 24376606 PMCID: PMC3869749 DOI: 10.1371/journal.pone.0082918] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/29/2013] [Indexed: 01/26/2023] Open
Abstract
Although hepatocellular carcinoma (HCC) is one of the most common malignancies and constitutes the third leading cause of cancer-related deaths, the underlying molecular mechanisms are not fully understood. In the present study, we demonstrate for the first time that hepatocytes express signalling lymphocytic activation molecule family member 3 (SLAMF3/CD229) but not other SLAMF members. We provide evidence to show that SLAMF3 is involved in the control of hepatocyte proliferation and in hepatocellular carcinogenesis. SLAMF3 expression is significantly lower in primary human HCC samples and HCC cell lines than in human healthy primary hepatocytes. In HCC cell lines, the restoration of high levels of SLAMF3 expression inhibited cell proliferation and migration and enhanced apoptosis. Furthermore, SLAMF3 expression was associated with inhibition of HCC xenograft progression in the nude mouse model. The restoration of SLAMF3 expression levels also decreased the phosphorylation of MAPK ERK1/2, JNK and mTOR. In samples from resected HCC patients, SLAMF3 expression levels were significantly lower in tumorous tissues than in peritumoral tissues. Our results identify SLAMF3 as a specific marker of normal hepatocytes and provide evidence for its potential role in the control of proliferation of HCC cells.
Collapse
Affiliation(s)
- Ingrid Marcq
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Rémy Nyga
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Flora Cartier
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
- INSERM U1053, Laboratoire de Physiologie du Cancer du Foie, Université Bordeaux Segalen, 146, rue Léo Saignat, Bordeaux, France
| | - Rabbind Singh Amrathlal
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Christèle Ossart
- Service d’hématologie Clinique et de thérapie cellulaire Centre Hospitalier Universitaire sud, Amiens, France
| | - Hakim Ouled-Haddou
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Hussein Ghamlouch
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Antoine Galmiche
- Service de Biochimie, Centre Hospitalier Universitaire sud, Amiens, France
| | - Denis Chatelain
- Service d’Anatomie Pathologique, Centre Hospitalier Universitaire sud, Amiens, France
| | - Luciane Lamotte
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Véronique Debuysscher
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
| | - Vincent Fuentes
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
- Service d’Immunologie, Centre Hospitalier Universitaire sud, Amiens, France
| | - Eric Nguyen-Khac
- Service Hepato-Gastroenterologie, Centre Hospitalier Universitaire sud, Amiens, France
| | - Jean-Marc Regimbeau
- Service de chirurgie digestive Centre Hospitalier Universitaire sud, Amiens, France
| | - Jean-Pierre Marolleau
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
- Service d’hématologie Clinique et de thérapie cellulaire Centre Hospitalier Universitaire sud, Amiens, France
| | - Sylvain Latour
- IRNEM U768, Hôpital Necker enfants maladies, Paris, France
| | - Hicham Bouhlal
- INSERM UMR925 and EA 4666 UFR de Médecine, CAP-Santé (FED 4231), Université de Picardie Jules Verne, Amiens, France
- Service d’hématologie Clinique et de thérapie cellulaire Centre Hospitalier Universitaire sud, Amiens, France
- * E-mail:
| |
Collapse
|
1227
|
Rosselli-Murai LK, Almeida LO, Zagni C, Galindo-Moreno P, Padial-Molina M, Volk SL, Murai MJ, Rios HF, Squarize CH, Castilho RM. Periostin responds to mechanical stress and tension by activating the MTOR signaling pathway. PLoS One 2013; 8:e83580. [PMID: 24349533 PMCID: PMC3862800 DOI: 10.1371/journal.pone.0083580] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 11/06/2013] [Indexed: 11/28/2022] Open
Abstract
Current knowledge about Periostin biology has expanded from its recognized functions in embryogenesis and bone metabolism to its roles in tissue repair and remodeling and its clinical implications in cancer. Emerging evidence suggests that Periostin plays a critical role in the mechanism of wound healing; however, the paracrine effect of Periostin in epithelial cell biology is still poorly understood. We found that epithelial cells are capable of producing endogenous Periostin that, unlike mesenchymal cell, cannot be secreted. Epithelial cells responded to Periostin paracrine stimuli by enhancing cellular migration and proliferation and by activating the mTOR signaling pathway. Interestingly, biomechanical stimulation of epithelial cells, which simulates tension forces that occur during initial steps of tissue healing, induced Periostin production and mTOR activation. The molecular association of Periostin and mTOR signaling was further dissected by administering rapamycin, a selective pharmacological inhibitor of mTOR, and by disruption of Raptor and Rictor scaffold proteins implicated in the regulation of mTORC1 and mTORC2 complex assembly. Both strategies resulted in ablation of Periostin-induced mitogenic and migratory activity. These results indicate that Periostin-induced epithelial migration and proliferation requires mTOR signaling. Collectively, our findings identify Periostin as a mechanical stress responsive molecule that is primarily secreted by fibroblasts during wound healing and expressed endogenously in epithelial cells resulting in the control of cellular physiology through a mechanism mediated by the mTOR signaling cascade.
Collapse
Affiliation(s)
- Luciana K. Rosselli-Murai
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Luciana O. Almeida
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Chiara Zagni
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Pablo Galindo-Moreno
- Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain
| | - Miguel Padial-Molina
- Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sarah L. Volk
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marcelo J. Murai
- The Division of Hematology and Oncology, University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan, United States of America
| | - Hector F. Rios
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Cristiane H. Squarize
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Rogerio M. Castilho
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| |
Collapse
|
1228
|
Serra C, Sandor NL, Jang H, Lee D, Toraldo G, Guarneri T, Wong S, Zhang A, Guo W, Jasuja R, Bhasin S. The effects of testosterone deprivation and supplementation on proteasomal and autophagy activity in the skeletal muscle of the male mouse: differential effects on high-androgen responder and low-androgen responder muscle groups. Endocrinology 2013; 154:4594-606. [PMID: 24105483 PMCID: PMC3836062 DOI: 10.1210/en.2013-1004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Men with prostate cancer who receive androgen deprivation therapy show profound skeletal muscle loss. We hypothesized that the androgen deficiency activates not only the ubiquitin-proteasome systems but also the autophagy and affects key aspects of the molecular cross talk between protein synthesis and degradation. Here, 2-month-old male mice were castrated and treated with either testosterone (T) propionate or vehicle for 7 days (short term) or 43 days (long term), and with and without hydroxyflutamide. Castrated mice showed rapid and profound atrophy of the levator ani muscle (high androgen responder) at short term and lesser atrophy of the triceps muscle (low androgen responder) at long term. Levator ani and triceps muscles of castrated mice showed increased level of autophagy markers and lysosome enzymatic activity; only the levator ani showed increased proteasomal enzymatic activity. The levator ani muscle of the castrated mice showed increased level and activation of forkhead box protein O3A, the inhibition of mechanistic target of rapamicyn, and the activation of tuberous sclerosis complex protein 2 and 5'-AMP-activated protein kinase. Similar results were obtained in the triceps muscle of castrated mice. T rescued the loss of muscle mass after orchiectomy and inhibited lysosome and proteasome pathways dose dependently and in a seemingly IGF-I-dependent manner. Hydroxyflutamide attenuated the effect of T in the levator ani muscle of castrated mice. In conclusion, androgen deprivation in adult mice induces muscle atrophy associated with proteasomal and lysosomal activity. T optimizes muscle protein balance by modulating the equilibrium between mechanistic target of rapamicyn and 5'-AMP-activated protein kinase pathways.
Collapse
Affiliation(s)
- Carlo Serra
- Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
1229
|
Nishitani S, Horie M, Ishizaki S, Yano H. Branched chain amino acid suppresses hepatocellular cancer stem cells through the activation of mammalian target of rapamycin. PLoS One 2013; 8:e82346. [PMID: 24312415 PMCID: PMC3842306 DOI: 10.1371/journal.pone.0082346] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 10/31/2013] [Indexed: 12/23/2022] Open
Abstract
Differentiation of cancer stem cells (CSCs) into cancer cells causes increased sensitivity to chemotherapeutic agents. Although inhibition of mammalian target of rapamycin (mTOR) leads to CSC survival, the effect of branched chain amino acids (BCAAs), an mTOR complex 1 (mTORC1) activator remains unknown. In this study, we examined the effects of BCAA on hepatocellular carcinoma (HCC) cells expressing a hepatic CSC marker, EpCAM. We examined the effects of BCAA and/or 5-fluorouracil (FU) on expression of EpCAM and other CSC-related markers, as well as cell proliferation in HCC cells and in a xenograft mouse model. We also characterized CSC-related and mTOR signal-related molecule expression and tumorigenicity in HCC cells with knockdown of Rictor or Raptor, or overexpression of constitutively active rheb (caRheb). mTOR signal-related molecule expression was also examined in BCAA-treated HCC cells. In-vitro BCAA reduced the frequency of EpCAM-positive cells and improved sensitivity to the anti-proliferative effect of 5-FU. Combined 5-FU and BCAA provided better antitumor efficacy than 5-FU alone in the xenograft model. Stimulation with high doses of BCAA activated mTORC1. Knockdown and overexpression experiments revealed that inhibition of mTOR complex 2 (mTORC2) or activation of mTORC1 led to decreased EpCAM expression and little or no tumorigenicity. BCAA may enhance the sensitivity to chemotherapy by reducing the population of cscs via the mTOR pathway. This result suggests the utility of BCAA in liver cancer therapy.
Collapse
Affiliation(s)
- Shinobu Nishitani
- Exploratory Research Laboratories, Research Center, Ajinomoto Pharmaceuticals, Co, Ltd, Kanagawa, Japan
| | - Mayumi Horie
- Exploratory Research Laboratories, Research Center, Ajinomoto Pharmaceuticals, Co, Ltd, Kanagawa, Japan
| | - Sonoko Ishizaki
- Exploratory Research Laboratories, Research Center, Ajinomoto Pharmaceuticals, Co, Ltd, Kanagawa, Japan
- * E-mail:
| | - Hirohisa Yano
- Department of Pathology, Kurume University School of Medicine, Kurume, Japan
| |
Collapse
|
1230
|
Tattoli I, Sorbara MT, Yang C, Tooze SA, Philpott DJ, Girardin SE. Listeria phospholipases subvert host autophagic defenses by stalling pre-autophagosomal structures. EMBO J 2013; 32:3066-78. [PMID: 24162724 PMCID: PMC3844955 DOI: 10.1038/emboj.2013.234] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/02/2013] [Indexed: 12/31/2022] Open
Abstract
Listeria can escape host autophagy defense pathways through mechanisms that remain poorly understood. We show here that in epithelial cells, Listeriolysin (LLO)-dependent cytosolic escape of Listeria triggered a transient amino-acid starvation host response characterized by GCN2 phosphorylation, ATF3 induction and mTOR inhibition, the latter favouring a pro-autophagic cellular environment. Surprisingly, rapid recovery of mTOR signalling was neither sufficient nor necessary for Listeria avoidance of autophagic targeting. Instead, we observed that Listeria phospholipases PlcA and PlcB reduced autophagic flux and phosphatidylinositol 3-phosphate (PI3P) levels, causing pre-autophagosomal structure stalling and preventing efficient targeting of cytosolic bacteria. In co-infection experiments, wild-type Listeria protected PlcA/B-deficient bacteria from autophagy-mediated clearance. Thus, our results uncover a critical role for Listeria phospholipases C in the inhibition of autophagic flux, favouring bacterial escape from host autophagic defense.
Collapse
Affiliation(s)
- Ivan Tattoli
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Department of Immunology, University of Toronto, Toronto, Canada
| | | | - Chloe Yang
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Sharon A Tooze
- Secretory Pathways Laboratory, London Research Institute, Cancer Research UK, London, UK
| | - Dana J Philpott
- Department of Immunology, University of Toronto, Toronto, Canada
| | - Stephen E Girardin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| |
Collapse
|
1231
|
Giovinazzo F, Schimmack S, Svejda B, Alaimo D, Pfragner R, Modlin I, Kidd M. Chromogranin A and its fragments as regulators of small intestinal neuroendocrine neoplasm proliferation. PLoS One 2013; 8:e81111. [PMID: 24260544 PMCID: PMC3834250 DOI: 10.1371/journal.pone.0081111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 10/17/2013] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Chromogranin A is a neuroendocrine secretory product and its loss is a feature of malignant NEN de-differentiation. We hypothesized that chromogranin A fragments were differentially expressed during NEN metastasis and played a role in the regulation of NEN proliferation. METHODS Chromogranin A mRNA (PCR) and protein (ELISA/western blot) were studied in 10 normal human mucosa, 5 enterochromaffin cell preparations, 26 small intestinal NEN primaries and 9 liver metastases. Cell viability (WST-1 assay), proliferation (bromodeoxyuridine ELISA) and expression of AKT/AKT-P (CASE ELISA/western blot) in response to chromogranin A silencing, inhibition of prohormone convertase and mTOR inhibition (RAD001/AKT antisense) as well as different chromogranin A fragments were examined in 4 SI-NEN cell lines. RESULTS Chromogranin A mRNA and protein levels were increased (37-340 fold, p<0.0001) in small intestinal NENs compared to normal enterochromaffin cells. Western blot identified chromogranin A-associated processing bands including vasostatin in small intestinal NENs as well as up-regulated expression of prohormone convertase in metastases. Proliferation in small intestinal NEN cell lines was decreased by silencing chromogranin A as well as by inhibition of prohormone convertase (p<0.05). This inhibition also decreased secretion of chromogranin A (p<0.05) and 5-HT (p<0.05) as well as expression of vasostatin. Metastatic small intestinal NEN cell lines were stimulated (50-80%, p<0.05) and AKT phosphorylated (Ser473: p<0.05) by vasostatin I, which was completely reversed by RAD001 (p<0.01) and AKT antisense (p<0.05) while chromostatin inhibited proliferation (~50%, p<0.05). CONCLUSION Chromogranin A was differentially regulated in primary and metastatic small intestinal NENs and cell lines. Chromogranin A fragments regulated metastatic small intestinal NEN proliferation via the AKT pathway indicating that CgA plays a far more complex role in the biology of these tumors than previously considered.
Collapse
Affiliation(s)
- Francesco Giovinazzo
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Laboratory of Translational Surgery-LURM, University of Verona, Verona, Italy
| | - Simon Schimmack
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
- University Hospital of General, Visceral- and Transplantation-Surgery of Heidelberg, Heidelberg, Germany
| | - Bernhard Svejda
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Pathophysiology and Immunology, University of Graz, Graz, Austria
| | - Daniele Alaimo
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Roswitha Pfragner
- Department of Pathophysiology and Immunology, University of Graz, Graz, Austria
| | - Irvin Modlin
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Mark Kidd
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
| |
Collapse
|
1232
|
Vakana E, Arslan AD, Szilard A, Altman JK, Platanias LC. Regulatory effects of sestrin 3 (SESN3) in BCR-ABL expressing cells. PLoS One 2013; 8:e78780. [PMID: 24260131 PMCID: PMC3832611 DOI: 10.1371/journal.pone.0078780] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 09/23/2013] [Indexed: 11/18/2022] Open
Abstract
Chronic myeloid leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL) are characterized by the presence of the BCR-ABL oncoprotein, which leads to activation of a plethora of pro-mitogenic and pro-survival pathways, including the mTOR signaling cascade. We provide evidence that in BCR-ABL expressing cells, treatment with tyrosine kinase inhibitors (TKIs) results in upregulation of mRNA levels and protein expression of sestrin3 (SESN3), a unique cellular inhibitor of mTOR complex 1 (mTORC1). Such upregulation appears to be mediated by regulatory effects on mTOR, as catalytic inhibition of the mTOR kinase also induces SESN3. Catalytic mTOR inhibition also results in upregulation of SESN3 expression in cells harboring the TKI-insensitive T315I-BCR-ABL mutant, which is resistant to imatinib mesylate. Overexpression of SESN3 results in inhibitory effects on different Ph+ leukemic cell lines including KT-1-derived leukemic precursors, indicating that SESN3 mediates anti-leukemic responses in Ph+ cells. Altogether, our findings suggest the existence of a novel mechanism for the generation of antileukemic responses in CML cells, involving upregulation of SESN3 expression.
Collapse
MESH Headings
- Animals
- Cell Line, Tumor
- Fusion Proteins, bcr-abl/biosynthesis
- Fusion Proteins, bcr-abl/genetics
- Gene Expression Regulation, Leukemic
- Heat-Shock Proteins/biosynthesis
- Heat-Shock Proteins/genetics
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Mechanistic Target of Rapamycin Complex 1
- Mice
- Multiprotein Complexes/antagonists & inhibitors
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Up-Regulation/genetics
Collapse
Affiliation(s)
- Eliza Vakana
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, Chicago, Illinois, United States of America
| | - Ahmet Dirim Arslan
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, Chicago, Illinois, United States of America
| | - Amy Szilard
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, Chicago, Illinois, United States of America
| | - Jessica K. Altman
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, Chicago, Illinois, United States of America
- Division of Hematology-Oncology, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
| | - Leonidas C. Platanias
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, Chicago, Illinois, United States of America
- Division of Hematology-Oncology, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
1233
|
Renna M, Bento CF, Fleming A, Menzies FM, Siddiqi FH, Ravikumar B, Puri C, Garcia-Arencibia M, Sadiq O, Corrochano S, Carter S, Brown SD, Acevedo-Arozena A, Rubinsztein DC. IGF-1 receptor antagonism inhibits autophagy. Hum Mol Genet 2013; 22:4528-44. [PMID: 23804751 PMCID: PMC3889807 DOI: 10.1093/hmg/ddt300] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 06/20/2013] [Indexed: 12/18/2022] Open
Abstract
Inhibition of the insulin/insulin-like growth factor signalling pathway increases lifespan and protects against neurodegeneration in model organisms, and has been considered as a potential therapeutic target. This pathway is upstream of mTORC1, a negative regulator of autophagy. Thus, we expected autophagy to be activated by insulin-like growth factor-1 (IGF-1) inhibition, which could account for many of its beneficial effects. Paradoxically, we found that IGF-1 inhibition attenuates autophagosome formation. The reduced amount of autophagosomes present in IGF-1R depleted cells can be, at least in part, explained by a reduced formation of autophagosomal precursors at the plasma membrane. In particular, IGF-1R depletion inhibits mTORC2, which, in turn, reduces the activity of protein kinase C (PKCα/β). This perturbs the actin cytoskeleton dynamics and decreases the rate of clathrin-dependent endocytosis, which impacts autophagosome precursor formation. Finally, with important implications for human diseases, we demonstrate that pharmacological inhibition of the IGF-1R signalling cascade reduces autophagy also in zebrafish and mice models. The novel link we describe here has important consequences for the interpretation of genetic experiments in mammalian systems and for evaluating the potential of targeting the IGF-1R receptor or modulating its signalling through the downstream pathway for therapeutic purposes under clinically relevant conditions, such as neurodegenerative diseases, where autophagy stimulation is considered beneficial.
Collapse
Affiliation(s)
- Maurizio Renna
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Carla F. Bento
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Angeleen Fleming
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
- Department of Physiology, Development and
Neuroscience, University of Cambridge,
Cambridge, UK
| | - Fiona M. Menzies
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Farah H. Siddiqi
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Brinda Ravikumar
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Claudia Puri
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Moises Garcia-Arencibia
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | - Oana Sadiq
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| | | | - Sarah Carter
- Mammalian Genetics Unit,
Medical Research Council, Harwell,
UK
| | | | | | - David C. Rubinsztein
- Department of Medical Genetics,
Cambridge Institute for Medical Research,
University of Cambridge, Wellcome/MRC Building,
Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY,
UK
| |
Collapse
|
1234
|
Oneyama C, Kito Y, Asai R, Ikeda JI, Yoshida T, Okuzaki D, Kokuda R, Kakumoto K, Takayama KI, Inoue S, Morii E, Okada M. MiR-424/503-mediated Rictor upregulation promotes tumor progression. PLoS One 2013; 8:e80300. [PMID: 24244675 PMCID: PMC3823661 DOI: 10.1371/journal.pone.0080300] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/01/2013] [Indexed: 12/27/2022] Open
Abstract
mTOR complex 2 (mTORC2) signaling is upregulated in multiple types of human cancer, but the molecular mechanisms underlying its activation and regulation remain elusive. Here, we show that microRNA-mediated upregulation of Rictor, an mTORC2-specific component, contributes to tumor progression. Rictor is upregulated via the repression of the miR-424/503 cluster in human prostate and colon cancer cell lines that harbor c-Src upregulation and in Src-transformed cells. The tumorigenicity and invasive activity of these cells were suppressed by re-expression of miR-424/503. Rictor upregulation promotes formation of mTORC2 and induces activation of mTORC2, resulting in promotion of tumor growth and invasion. Furthermore, downregulation of miR-424/503 is associated with Rictor upregulation in colon cancer tissues. These findings suggest that the miR-424/503-Rictor pathway plays a crucial role in tumor progression.
Collapse
Affiliation(s)
- Chitose Oneyama
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- * E-mail:
| | - Yoriko Kito
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Rei Asai
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Jun-ichiro Ikeda
- Department of Pathology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Takuya Yoshida
- Laboratory of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Daisuke Okuzaki
- DNA-chip Developmental Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Rie Kokuda
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Kyoko Kakumoto
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Ken-ichi Takayama
- Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Satoshi Inoue
- Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama, Japan
| | - Eiichi Morii
- Department of Pathology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Masato Okada
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| |
Collapse
|
1235
|
Fong JT, Jacobs RJ, Moravec DN, Uppada SB, Botting GM, Nlend M, Puri N. Alternative signaling pathways as potential therapeutic targets for overcoming EGFR and c-Met inhibitor resistance in non-small cell lung cancer. PLoS One 2013; 8:e78398. [PMID: 24223799 PMCID: PMC3817236 DOI: 10.1371/journal.pone.0078398] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 09/11/2013] [Indexed: 01/21/2023] Open
Abstract
The use of tyrosine kinase inhibitors (TKIs) against EGFR/c-Met in non-small cell lung cancer (NSCLC) has been shown to be effective in increasing patient progression free survival (PFS), but their efficacy is limited due to the development of resistance and tumor recurrence. Therefore, understanding the molecular mechanisms underlying development of drug resistance in NSCLC is necessary for developing novel and effective therapeutic approaches to improve patient outcome. This study aims to understand the mechanism of EGFR/c-Met tyrosine kinase inhibitor (TKI) resistance in NSCLC. H2170 and H358 cell lines were made resistant to SU11274, a c-Met inhibitor, and erlotinib, an EGFR inhibitor, through step-wise increases in TKI exposure. The IC50 concentrations of resistant lines exhibited a 4–5 and 11–22-fold increase for SU11274 and erlotinib, respectively, when compared to parental lines. Furthermore, mTOR and Wnt signaling was studied in both cell lines to determine their roles in mediating TKI resistance. We observed a 2–4-fold upregulation of mTOR signaling proteins and a 2- to 8-fold upregulation of Wnt signaling proteins in H2170 erlotinib and SU11274 resistant cells. H2170 and H358 cells were further treated with the mTOR inhibitor everolimus and the Wnt inhibitor XAV939. H358 resistant cells were inhibited by 95% by a triple combination of everolimus, erlotinib and SU11274 in comparison to 34% by a double combination of these drugs. Parental H2170 cells displayed no sensitivity to XAV939, while resistant cells were significantly inhibited (39%) by XAV939 as a single agent, as well as in combination with SU11274 and erlotinib. Similar results were obtained with H358 resistant cells. This study suggests a novel molecular mechanism of drug resistance in lung cancer.
Collapse
Affiliation(s)
- Jason T. Fong
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
| | - Ryan J. Jacobs
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
| | - David N. Moravec
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
| | - Srijayaprakash B. Uppada
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
| | - Gregory M. Botting
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
| | - Marie Nlend
- Thermo Fisher Scientific, Rockford, Illinois, United States of America
| | - Neelu Puri
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, Illinois, United States
- * E-mail:
| |
Collapse
|
1236
|
Wilson GJ, Bunpo P, Cundiff JK, Wek RC, Anthony TG. The eukaryotic initiation factor 2 kinase GCN2 protects against hepatotoxicity during asparaginase treatment. Am J Physiol Endocrinol Metab 2013; 305:E1124-33. [PMID: 24002574 PMCID: PMC3840205 DOI: 10.1152/ajpendo.00080.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Asparaginase is an important drug in the treatment regimen for acute lymphoblastic leukemia. Asparaginase depletes circulating asparagine and glutamine, activating an amino acid stress response (AAR) involving phosphorylation of eukaryotic initiation factor 2 (eIF2) by general control nonderepressible kinase 2 (GCN2). We hypothesized that GCN2 functions to mitigate hepatic stress during asparaginase therapy by activating the AAR. To test this idea, C57BL/6J wild-type mice (Gcn2(+/+)) and those deleted for Gcn2 (Gcn2(-/-)) were injected with asparaginase or saline excipient one time daily for 1 or 6 days. In liver, increased phosphorylation of eIF2 and mRNA expression of AAR target genes activating transcription factor 4, asparagine synthetase, eIF4E-binding protein 1, and CAAT enhancer-binding protein homologous protein were significantly blunted or blocked in the liver of Gcn2(-/-) mice. Loss of AAR during asparaginase coincided with increases in mammalian target of rapamycin signaling, hepatic triglyceride accumulation, and DNA damage in association with genetic markers of oxidative stress (glutathione peroxidase) and inflammation (tumor necrosis factor alpha-α). Although asparaginase depleted circulating asparagine in both Gcn2(+/+) and Gcn2(-/-) mice, all other amino acids, including plasma glutamine, were elevated in the plasma of Gcn2(-/-) mice. This study shows that loss of GCN2 promotes oxidative stress and inflammatory-mediated DNA damage during asparaginase therapy, suggesting that patients with reduced or dysfunctional AAR may be at risk of developing hepatic complications during asparaginase treatment.
Collapse
Affiliation(s)
- Gabriel J Wilson
- Department of Nutritional Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | | | | | | | | |
Collapse
|
1237
|
Abstract
PURPOSE OF REVIEW To highlight recent research on amino acid sensing and signaling and the role of amino acid transporters in the regulation of human skeletal muscle protein metabolism. RECENT FINDINGS The mechanisms that sense amino acid availability and activate mechanistic target of rapamycin complex 1 signaling and protein synthesis are emerging, with multiple new proteins and intracellular amino acid sensors recently identified. Amino acid transporters have a role in the delivery of amino acids to these intracellular sensors and new findings provide further support for amino acid transporters as possible extracellular amino acid sensors. There is growing evidence in human skeletal muscle that amino acid transporter expression is dynamic and responsive to various stimuli, indicating amino acid transporters may have a unique role in the regulation of human skeletal muscle adaptation. SUMMARY There is a clear need to further examine the role of amino acid transporters in human skeletal muscle and their link to cellular amino acid sensing and signaling in the control of protein metabolism. A better understanding of amino acid transport and transporters will allow us to optimize nutritional strategies to accelerate muscle health and improve outcomes for clinical populations.
Collapse
Affiliation(s)
- Jared M Dickinson
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas, USA
| | | |
Collapse
|
1238
|
He J, Wang MY, Qiu LX, Zhu ML, Shi TY, Zhou XY, Sun MH, Yang YJ, Wang JC, Jin L, Wang YN, Li J, Yu HP, Wei QY. Genetic variations of mTORC1 genes and risk of gastric cancer in an Eastern Chinese population. Mol Carcinog 2013; 52 Suppl 1:E70-9. [PMID: 23423739 DOI: 10.1002/mc.22013] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/09/2012] [Accepted: 01/13/2013] [Indexed: 02/05/2023]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) plays an important role in maintaining proper cellular functions, and genetic variations in this complex may affect cancer risk. In this study, we examined the associations between eight potential functional single nucleotide polymorphisms in the mTORC1 genes (rs2536T>C and rs1883965G>A for mTOR, rs3160T>C, and rs26865A>G for mLST8, rs3751934C>A, rs1062935T>C, rs3751932T>C, and rs12602885G>A for Raptor, not included in published gastric cancer genome-wide association studies) and gastric cancer risk in 1125 gastric cancer cases and 1196 cancer-free controls. We performed conditional logistic regression and multifactor dimensionality reduction (MDR) analyses to assess their associations with gastric cancer risk. We also used false-positive report probabilities (FPRP) for assessing significant findings. We found that only the rs1883965A variant genotypes were associated with an increased risk of gastric cancer (AG vs. GG: adjusted odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.00-1.59; AA vs. GG: adjusted OR = 1.85, 95% CI = 0.67-5.16 and dominant model: adjusted OR = 1.28, 95% CI = 1.03-1.61). Patients with ≥1 risk genotypes of mTOR had significant increased risk (adjusted OR = 1.25, 95% CI = 1.04-1.49), compared with those having zero risk genotypes. In the stratified analysis, the risk effect of the rs1883965 AG/AA genotypes was evident in subgroups of ever-smokers, non-gastric cardia adenocarcinoma and clinical stage I + II, which were noteworthy findings as evaluated by FPRP. The MDR analysis identified smoking status and rs1883965 as the strongest two-factors for gastric cancer risk. These data support the hypothesis that functional polymorphisms of mTOR may contribute to gastric cancer risk. Clearly, our results require validation in larger studies with different ethnic populations.
Collapse
Affiliation(s)
- Jing He
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
1239
|
Tuval-Kochen L, Paglin S, Keshet G, Lerenthal Y, Nakar C, Golani T, Toren A, Yahalom J, Pfeffer R, Lawrence Y. Eukaryotic initiation factor 2α--a downstream effector of mammalian target of rapamycin--modulates DNA repair and cancer response to treatment. PLoS One 2013; 8:e77260. [PMID: 24204783 PMCID: PMC3808413 DOI: 10.1371/journal.pone.0077260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 08/30/2013] [Indexed: 02/06/2023] Open
Abstract
In an effort to circumvent resistance to rapamycin – an mTOR inhibitor - we searched for novel rapamycin-downstream-targets that may be key players in the response of cancer cells to therapy. We found that rapamycin, at nM concentrations, increased phosphorylation of eukaryotic initiation factor (eIF) 2α in rapamycin-sensitive and estrogen-dependent MCF-7 cells, but had only a minimal effect on eIF2α phosphorylation in the rapamycin-insensitive triple-negative MDA-MB-231 cells. Addition of salubrinal – an inhibitor of eIF2α dephosphorylation – decreased expression of a surface marker associated with capacity for self renewal, increased senescence and induced clonogenic cell death, suggesting that excessive phosphorylation of eIF2α is detrimental to the cells' survival. Treating cells with salubrinal enhanced radiation-induced increase in eIF2α phosphorylation and clonogenic death and showed that irradiated cells are more sensitive to increased eIF2α phosphorylation than non-irradiated ones. Similar to salubrinal - the phosphomimetic eIF2α variant - S51D - increased sensitivity to radiation, and both abrogated radiation-induced increase in breast cancer type 1 susceptibility gene, thus implicating enhanced phosphorylation of eIF2α in modulation of DNA repair. Indeed, salubrinal inhibited non-homologous end joining as well as homologous recombination repair of double strand breaks that were induced by I-SceI in green fluorescent protein reporter plasmids. In addition to its effect on radiation, salubrinal enhanced eIF2α phosphorylation and clonogenic death in response to the histone deacetylase inhibitor – vorinostat. Finally, the catalytic competitive inhibitor of mTOR - Ku-0063794 - increased phosphorylation of eIF2α demonstrating further the involvement of mTOR activity in modulating eIF2α phosphorylation. These experiments suggest that excessive phosphorylation of eIF2α decreases survival of cancer cells; making eIF2α a worthy target for drug development, with the potential to enhance the cytotoxic effects of established anti-neoplastic therapies and circumvent resistance to rapalogues and possibly to other drugs that inhibit upstream components of the mTOR pathway.
Collapse
MESH Headings
- Antineoplastic Agents/pharmacology
- Cell Line, Tumor
- Cellular Senescence/drug effects
- Cinnamates/pharmacology
- DNA Repair/drug effects
- DNA, Neoplasm/genetics
- DNA, Neoplasm/metabolism
- Deoxyribonucleases, Type II Site-Specific/genetics
- Deoxyribonucleases, Type II Site-Specific/metabolism
- Drug Resistance, Neoplasm/drug effects
- Drug Resistance, Neoplasm/genetics
- Drug Resistance, Neoplasm/radiation effects
- Eukaryotic Initiation Factor-2/antagonists & inhibitors
- Eukaryotic Initiation Factor-2/genetics
- Eukaryotic Initiation Factor-2/metabolism
- Female
- Gamma Rays
- Gene Expression Regulation, Neoplastic/drug effects
- Gene Expression Regulation, Neoplastic/radiation effects
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Humans
- Hydroxamic Acids/pharmacology
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Morpholines/pharmacology
- Peptidomimetics/pharmacology
- Phosphorylation/drug effects
- Phosphorylation/radiation effects
- Pyrimidines/pharmacology
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Signal Transduction
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Thiourea/analogs & derivatives
- Thiourea/pharmacology
- Transgenes
- Vorinostat
Collapse
Affiliation(s)
- Liron Tuval-Kochen
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Shoshana Paglin
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
- * E-mail:
| | - Gilmor Keshet
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Yaniv Lerenthal
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Charles Nakar
- Department of Oncology, Memorial Sloan-Kettering, New-York, New York, United States of America
| | - Tamar Golani
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Amos Toren
- Department of Pediatric Hematology-Oncology, Safra Children's Hospital, Tel-Hashomer, Ramat-Gan, Israel
| | - Joachim Yahalom
- Department of Oncology, Memorial Sloan-Kettering, New-York, New York, United States of America
| | - Raphael Pfeffer
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| | - Yaacov Lawrence
- Cancer Research Center, Chaim Sheba Medical Center, Tel-Hashomer, Ramat-Gan, Israel
| |
Collapse
|
1240
|
Abstract
Lysosomes are membrane-bound organelles that contain acid hydrolases that degrade cellular proteins, lipids, nucleic acids, and oligosaccharides, and are important for cellular maintenance and protection against age-related decline. Lysosome related organelles (LROs) are specialized lysosomes found in organisms from humans to worms, and share many of the features of classic lysosomes. Defective LROs are associated with human immune disorders and neurological disease. Caenorhabditis elegans LROs are the site of concentration of vital dyes such as Nile red as well as age-associated autofluorescence. Even though certain short-lived mutants have high LRO Nile red and high autofluorescence, and other long-lived mutants have low LRO Nile red and low autofluorescence, these two biologies are distinct. We identified a genetic pathway that modulates aging-related LRO phenotypes via serotonin signaling and the gene kat-1, which encodes a mitochondrial ketothiolase. Regulation of LRO phenotypes by serotonin and kat-1 in turn depend on the proton-coupled, transmembrane transporter SKAT-1. skat-1 loss of function mutations strongly suppress the high LRO Nile red accumulation phenotype of kat-1 mutation. Using a systems approach, we further analyzed the role of 571 genes in LRO biology. These results highlight a gene network that modulates LRO biology in a manner dependent upon the conserved protein kinase TOR complex 2. The results implicate new genetic pathways involved in LRO biology, aging related physiology, and potentially human diseases of the LRO. Lysosome related organelles (LROs) are specialized, membrane-bound organelles that share many common features of canonical lysosomes. Mutations in critical components of LRO biogenesis lead to human diseases of immunity, blood clotting, and pigmentation. In Caenorhabditis elegans, LROs are the site of accumulation of aging-related autofluorescence and the vital dye Nile red when fed to living C. elegans. Through classical genetics we show that the LRO is regulated by a conserved genetic pathway involving serotonin, a mitochondrial ketothiolase, and a proton-coupled solute transporter. Though previously thought to be linked in an obligatory manner, through systems level analysis we show that accumulation of C. elegans LRO Nile red and autofluorescence are mechanistically distinct processes. Contrary to the prior notion that LRO Nile red indicates lipid stores, we show that LRO Nile red is not correlated with, and may be anticorrelated with, C. elegans lipid stores. Using hundreds of candidate gene inactivations that disrupt Nile red accumulation, we determined which LRO regulatory genes specifically interact with 6 genetic mutants known to have altered LRO biology, identifying changes specifically dependent upon target of rapamycin complex 2 signaling. These data reveal relationships between LRO biology and aging and metabolism in C. elegans.
Collapse
Affiliation(s)
- Alexander A. Soukas
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (AAS); (GR)
| | - Christopher E. Carr
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Earth and Interplanetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (AAS); (GR)
| |
Collapse
|
1241
|
Tanaka Y, Matsuwaki T, Yamanouchi K, Nishihara M. Increased lysosomal biogenesis in activated microglia and exacerbated neuronal damage after traumatic brain injury in progranulin-deficient mice. Neuroscience 2013; 250:8-19. [PMID: 23830905 DOI: 10.1016/j.neuroscience.2013.06.049] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/11/2013] [Accepted: 06/21/2013] [Indexed: 01/12/2023]
Abstract
Progranulin (PGRN) is known to play a role in the pathogenesis of neurodegenerative diseases. Recently, it has been demonstrated that patients with the homozygous mutation in the GRN gene present with neuronal ceroid lipofuscinosis, and there is growing evidence that PGRN is related to lysosomal function. In the present study, we investigated the possible role of PGRN in the lysosomes of activated microglia in the cerebral cortex after traumatic brain injury (TBI). We showed that the mouse GRN gene has two possible coordinated lysosomal expression and regulation (CLEAR) sequences that bind to transcription factor EB (TFEB), a master regulator of lysosomal genes. PGRN was colocalized with Lamp1, a lysosomal marker, and Lamp1-positive areas in GRN-deficient (KO) mice were significantly expanded compared with wild-type (WT) mice after TBI. Expression of all the lysosome-related genes examined in KO mice was significantly higher than that in WT mice. The number of activated microglia with TFEB localized to the nucleus was also significantly increased in KO as compared with WT mice. Since the TFEB translocation is regulated by the mammalian target of rapamycin complex 1 (mTORC1) activity in the lysosome, we compared ribosomal S6 kinase 1 (S6K1) phosphorylation that reflects mTORC1 activity. S6K1 phosphorylation in KO mice was significantly lower than that in WT mice. In addition, the number of nissl-positive and fluoro-jade B-positive cells around the injury was significantly decreased and increased, respectively, in KO as compared with WT mice. These results suggest that PGRN localized in the lysosome is involved in the activation of mTORC1, and its deficiency leads to increased TFEB nuclear translocation with a resultant increase in lysosomal biogenesis in activated microglia and exacerbated neuronal damage in the cerebral cortex after TBI.
Collapse
Affiliation(s)
- Y Tanaka
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | | | | |
Collapse
|
1242
|
Sun ZJ, Zhang L, Zhang W, Hall B, Bian Y, Kulkarni AB. Inhibition of mTOR reduces anal carcinogenesis in transgenic mouse model. PLoS One 2013; 8:e74888. [PMID: 24124460 PMCID: PMC3790781 DOI: 10.1371/journal.pone.0074888] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 08/06/2013] [Indexed: 01/09/2023] Open
Abstract
The molecular mechanism of human anal squamous cell carcinoma (ASCC) is unclear, and the accumulating evidence indicate association of ASCC with the activation of the Akt/mTOR pathway. Here we describe a mouse model with spontaneous anal squamous cell cancer, wherein a combined deletion of Tgfbr1 and Pten in stratified squamous epithelia was induced using inducible K14-Cre. Histopathologic analyses confirmed that 33.3% of the mice showed increased susceptibility to ASCC and precancerous lesions. Biomarker analyses demonstrated that the activation of the Akt pathway in ASCC of the Tgfbr1 and Pten double knockout (2cKO) mouse was similar to that observed in human anal cancer. Chemopreventive experiments using mTOR inhibitor-rapamycin treatment significantly delayed the onset of the ASCC tumors and reduced the tumor burden in 2cKO mice by decreasing the phosphorylation of Akt and S6. This is the first conditional knockout mouse model used for investigating the contributions of viral and cellular factors in anal carcinogenesis without carcinogen-mediated induction, and it would provide a platform for assessing new therapeutic modalities for treating and/or preventing this type of cancer.
Collapse
Affiliation(s)
- Zhi-Jun Sun
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (ABK); (ZJS)
| | - Lu Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Wei Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Bradford Hall
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yansong Bian
- Head and Neck Surgery Branch, National Institute of Deafness and Other Communicative Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ashok B. Kulkarni
- Functional Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (ABK); (ZJS)
| |
Collapse
|
1243
|
Xu B, Lee KK, Zhang L, Gerton JL. Stimulation of mTORC1 with L-leucine rescues defects associated with Roberts syndrome. PLoS Genet 2013; 9:e1003857. [PMID: 24098154 PMCID: PMC3789817 DOI: 10.1371/journal.pgen.1003857] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 08/21/2013] [Indexed: 12/22/2022] Open
Abstract
Roberts syndrome (RBS) is a human disease characterized by defects in limb and craniofacial development and growth and mental retardation. RBS is caused by mutations in ESCO2, a gene which encodes an acetyltransferase for the cohesin complex. While the essential role of the cohesin complex in chromosome segregation has been well characterized, it plays additional roles in DNA damage repair, chromosome condensation, and gene expression. The developmental phenotypes of Roberts syndrome and other cohesinopathies suggest that gene expression is impaired during embryogenesis. It was previously reported that ribosomal RNA production and protein translation were impaired in immortalized RBS cells. It was speculated that cohesin binding at the rDNA was important for nucleolar form and function. We have explored the hypothesis that reduced ribosome function contributes to RBS in zebrafish models and human cells. Two key pathways that sense cellular stress are the p53 and mTOR pathways. We report that mTOR signaling is inhibited in human RBS cells based on the reduced phosphorylation of the downstream effectors S6K1, S6 and 4EBP1, and this correlates with p53 activation. Nucleoli, the sites of ribosome production, are highly fragmented in RBS cells. We tested the effect of inhibiting p53 or stimulating mTOR in RBS cells. The rescue provided by mTOR activation was more significant, with activation rescuing both cell division and cell death. To study this cohesinopathy in a whole animal model we used ESCO2-mutant and morphant zebrafish embryos, which have developmental defects mimicking RBS. Consistent with RBS patient cells, the ESCO2 mutant embryos show p53 activation and inhibition of the TOR pathway. Stimulation of the TOR pathway with L-leucine rescued many developmental defects of ESCO2-mutant embryos. Our data support the idea that RBS can be attributed in part to defects in ribosome biogenesis, and stimulation of the TOR pathway has therapeutic potential.
Collapse
Affiliation(s)
- Baoshan Xu
- Stowers Institute for Medical Research, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
| | - Kenneth K. Lee
- Stowers Institute for Medical Research, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
| | - Lily Zhang
- Stowers Institute for Medical Research, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
| | - Jennifer L. Gerton
- Stowers Institute for Medical Research, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
- Department of Biochemistry and Molecular Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
| |
Collapse
|
1244
|
Sharvit E, Abramovitch S, Reif S, Bruck R. Amplified inhibition of stellate cell activation pathways by PPAR-γ, RAR and RXR agonists. PLoS One 2013; 8:e76541. [PMID: 24098526 PMCID: PMC3788137 DOI: 10.1371/journal.pone.0076541] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 08/28/2013] [Indexed: 02/06/2023] Open
Abstract
Peroxisome proliferator activator receptors (PPAR) ligands such as 15-Δ12,13-prostaglandin L(2) [PJ] and all trans retinoic acid (ATRA) have been shown to inhibit the development of liver fibrosis. The role of ligands of retinoic X receptor (RXR) and its ligand, 9-cis, is less clear. The purpose of this study was to investigate the effects of combined treatment of the three ligends, PJ, ATRA and 9-cis, on key events during liver fibrosis in rat primary hepatic stellate cells (HSCs). We found that the anti-proliferative effect of the combined treatment of PJ, ATRA and 9-cis on HSCs was additive. Further experiments revealed that this inhibition was due to cell cycle arrest at the G0/G1 phase as demonstrated by FACS analysis. In addition, the combined treatment reduced cyclin D1 expression and increased p21 and p27 protein levels. Furthermore, we found that the three ligands down regulated the phosphorylation of mTOR and p70(S6K). The activation of HSCs was also inhibited by the three ligands as shown by inhibition of vitamin A lipid droplets depletion from HSCs. Studies using real time PCR and western blot analysis showed marked inhibition of collagen Iα1 and αSMA by the combination of the three ligands. These findings suggest that the combined use of PJ, ATRA and 9-cis causes inhibition of cell proliferation by cell cycle arrest and down-regulation of fibrotic markers to a greater extent compared to each of the ligands alone.
Collapse
Affiliation(s)
- Efrat Sharvit
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shirley Abramovitch
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Shimon Reif
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Pediatric Gastroenterology Unit, Dana Children’s Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Rafael Bruck
- Institute of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
1245
|
Bloor ID, Sébert SP, Saroha V, Gardner DS, Keisler DH, Budge H, Symonds ME, Mahajan RP. Sex differences in metabolic and adipose tissue responses to juvenile-onset obesity in sheep. Endocrinology 2013; 154:3622-31. [PMID: 23885012 DOI: 10.1210/en.2013-1207] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sex is a major factor determining adipose tissue distribution and the subsequent adverse effects of obesity-related disease including type 2 diabetes. The role of gender on juvenile obesity and the accompanying metabolic and inflammatory responses is not well established. Using an ovine model of juvenile onset obesity induced by reduced physical activity, we examined the effect of gender on metabolic, circulatory, and related inflammatory and energy-sensing profiles of the major adipose tissue depots. Despite a similar increase in fat mass with obesity between genders, males demonstrated a higher storage capacity of lipids within perirenal-abdominal adipocytes and exhibited raised insulin. In contrast, obese females became hypercortisolemic, a response that was positively correlated with central fat mass. Analysis of gene expression in perirenal-abdominal adipose tissue demonstrated the stimulation of inflammatory markers in males, but not females, with obesity. Obese females displayed increased expression of genes involved in the glucocorticoid axis and energy sensing in perirenal-abdominal, but not omental, adipose tissue, indicating a depot-specific mechanism that may be protective from the adverse effects of metabolic dysfunction and inflammation. In conclusion, young males are at a greater risk than females to the onset of comorbidities associated with juvenile-onset obesity. These sex-specific differences in cortisol and adipose tissue could explain the earlier onset of the metabolic-related diseases in males compared with females after obesity.
Collapse
Affiliation(s)
- Ian D Bloor
- Academic Division of Child Health School of Clinical Sciences, E Floor, East Block, Queen's Medical Centre, University Hospital, The University of Nottingham, Nottingham NG7 2UH, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
1246
|
Tate JJ, Cooper TG. Five conditions commonly used to down-regulate tor complex 1 generate different physiological situations exhibiting distinct requirements and outcomes. J Biol Chem 2013; 288:27243-27262. [PMID: 23935103 PMCID: PMC3779721 DOI: 10.1074/jbc.m113.484386] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 08/08/2013] [Indexed: 11/06/2022] Open
Abstract
Five different physiological conditions have been used interchangeably to establish the sequence of molecular events needed to achieve nitrogen-responsive down-regulation of TorC1 and its subsequent regulation of downstream reporters: nitrogen starvation, methionine sulfoximine (Msx) addition, nitrogen limitation, rapamycin addition, and leucine starvation. Therefore, we tested a specific underlying assumption upon which the interpretation of data generated by these five experimental perturbations is premised. It is that they generate physiologically equivalent outcomes with respect to TorC1, i.e. its down-regulation as reflected by TorC1 reporter responses. We tested this assumption by performing head-to-head comparisons of the requirements for each condition to achieve a common outcome for a downstream proxy of TorC1 inactivation, nuclear Gln3 localization. We demonstrate that the five conditions for down-regulating TorC1 do not elicit physiologically equivalent outcomes. Four of the methods exhibit hierarchical Sit4 and PP2A phosphatase requirements to elicit nuclear Gln3-Myc(13) localization. Rapamycin treatment required Sit4 and PP2A. Nitrogen limitation and short-term nitrogen starvation required only Sit4. G1 arrest-correlated, long-term nitrogen starvation and Msx treatment required neither PP2A nor Sit4. Starving cells of leucine or treating them with leucyl-tRNA synthetase inhibitors did not elicit nuclear Gln3-Myc(13) localization. These data indicate that the five commonly used nitrogen-related conditions of down-regulating TorC1 are not physiologically equivalent and minimally involve partially differing regulatory mechanisms. Further, identical requirements for Msx treatment and long-term nitrogen starvation raise the possibility that their effects are achieved through a common regulatory pathway with glutamine, a glutamate or glutamine metabolite level as the sensed metabolic signal.
Collapse
Affiliation(s)
- Jennifer J Tate
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Terrance G Cooper
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
| |
Collapse
|
1247
|
Abstract
Melanosomes are lysosome-related organelles that serve as specialized sites of melanin synthesis and storage in melanocytes. The progression of melanosomes through the different stages of their formation requires trafficking of specific proteins and membrane constituents in a sequential manner, which is likely to deploy ubiquitous cellular machinery along with melanocyte-specific proteins. Recent evidence revealed a connection between melanogenesis and the autophagy machinery, suggesting a novel role for members of the latter in melanocytes. Here we focused on ULK1, a key autophagy protein which is negatively regulated by mTORC1, to assess its potential role in melanogenesis in MNT-1 cells. We found that ULK1 depletion causes an increase in melanin levels, suggesting an inhibitory function for this protein in melanogenesis. Furthermore, this increase was accompanied by increased transcription of MITF (microphthalmia-associated transcription factor) and tyrosinase and by elevated protein levels of tyrosinase, the rate-limiting factor in melanin biogenesis. We also provide evidence to show that ULK1 function in this context is independent of the canonical ULK1 autophagy partners, ATG13 and FIP200. Furthermore we show that regulation of melanogenesis by ULK1 is independent of mTORC1 inhibition. Our data thus provide intriguing insights regarding the involvement of the key regulatory autophagy machinery in melanogenesis.
Collapse
Affiliation(s)
- Eyal Kalie
- Secretory Pathways Laboratory, London Research Institute, Cancer Research UK, London, United Kingdom
| | - Minoo Razi
- Secretory Pathways Laboratory, London Research Institute, Cancer Research UK, London, United Kingdom
| | - Sharon A. Tooze
- Secretory Pathways Laboratory, London Research Institute, Cancer Research UK, London, United Kingdom
| |
Collapse
|
1248
|
Suzuki S, Nozawa Y, Tsukamoto S, Kaneko T, Imai H, Minami N. ING3 is essential for asymmetric cell division during mouse oocyte maturation. PLoS One 2013; 8:e74749. [PMID: 24066152 PMCID: PMC3774679 DOI: 10.1371/journal.pone.0074749] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/05/2013] [Indexed: 12/27/2022] Open
Abstract
ING3 (inhibitor of growth family, member 3) is a subunit of the nucleosome acetyltransferase of histone 4 (NuA4) complex, which activates gene expression. ING3, which contains a plant homeodomain (PHD) motif that can bind to trimethylated lysine 4 on histone H3 (H3K4me3), is ubiquitously expressed in mammalian tissues and governs transcriptional regulation, cell cycle control, and apoptosis via p53-mediated transcription or the Fas/caspase-8 pathway. Thus, ING3 plays a number of important roles in various somatic cells. However, the role(s) of ING3 in germ cells remains unknown. Here, we show that loss of ING3 function led to the failure of asymmetric cell division and cortical reorganization in the mouse oocyte. Immunostaining showed that in fully grown germinal vesicle (GV) oocytes, ING3 localized predominantly in the GV. After germinal vesicle breakdown (GVBD), ING3 homogeneously localized in the cytoplasm. In oocytes where Ing3 was targeted by siRNA microinjection, we observed symmetric cell division during mouse oocyte maturation. In those oocytes, oocyte polarization was not established due to the failure to form an actin cap or a cortical granule-free domain (CGFD), the lack of which inhibited spindle migration. These features were among the main causes of abnormal symmetric cell division. Interestingly, an analysis of the mRNA expression levels of genes related to asymmetric cell division revealed that only mTOR was downregulated, and, furthermore, that genes downstream of mTOR (e.g., Cdc42, Rac1, and RhoA) were also downregulated in siIng3-injected oocytes. Therefore, ING3 may regulate asymmetric cell division through the mTOR pathway during mouse oocyte maturation.
Collapse
Affiliation(s)
- Shinnosuke Suzuki
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Yusuke Nozawa
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Satoshi Tsukamoto
- Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, Chiba, Japan
| | - Takehito Kaneko
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroshi Imai
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Naojiro Minami
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- * E-mail:
| |
Collapse
|
1249
|
Wu P, Jiang J, Liu Y, Hu K, Jiang WD, Li SH, Feng L, Zhou XQ. Dietary choline modulates immune responses, and gene expressions of TOR and eIF4E-binding protein2 in immune organs of juvenile Jian carp (Cyprinus carpio var. Jian). Fish Shellfish Immunol 2013; 35:697-706. [PMID: 23774323 DOI: 10.1016/j.fsi.2013.05.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 03/20/2013] [Accepted: 05/28/2013] [Indexed: 06/02/2023]
Abstract
The present work evaluates the effects of various levels of dietary choline on immune parameters, immune-related gene expression and protection against Aeromonas hydrophila (AH) in juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed with six different experimental diets containing graded levels of choline at 165 (choline-deficient control), 310, 607, 896, 1167 and 1820 mg kg(-1) diet for 65 days. At the end of the feeding trail, Fish were challenged with AH and mortalities were recorded over 17 days. Dietary choline significantly enhanced spleen and head kidney weights, spleen index, red blood cell and white blood cell counts, and intestinal Lactobacillus counts of juvenile Jian carp; whereas, intestinal Escherichia coli and A. hydrophila counts decreased. Moreover, the post-challenge survival rate, leucocyte phagocytic capacity, serum lysozyme and acid phosphatase activities, hemagglutination titer, complement 3 and 4 contents, immunoglobulin M content, and anti-AH antibody titer were significantly enhanced by choline and the lowest in choline-deficient group, while serum total iron-binding capacity was the highest in choline-deficient group. The relative gene expressions of interleukin 10 in spleen and head kidney, target of rapamycin (TOR) in spleen and eIF4E-binding protein2 (4E-BP2) in head kidney significantly increased with increasing of dietary choline up to a certain point. However, the relative gene expressions of interleukin 1β, tumor necrosis factor α and transforming growth factor β2 in spleen and head kidney, TOR in head kidney and 4E-BP2 in spleen significantly decreased. In conclusion, dietary choline improved disease resistance, enhanced the immune function, and regulated immune-related gene expression of juvenile Jian carp.
Collapse
Affiliation(s)
- Pei Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China
| | | | | | | | | | | | | | | |
Collapse
|
1250
|
Abstract
Pediatric low-grade gliomas (pLGG) account for more brain tumors in children than any other histologic subtype. While surgery, chemotherapy and radiation remain the mainstay of upfront treatment, recent advances in molecular interrogation of pLGG have shown a small number of recurring genetic mutations in these tumors that might be exploited therapeutically. Notable findings include abnormalities in the RAS/MAP kinase pathway such as NF-1 loss or BRAF activation and mTOR activation. Recent identification of activating re-arrangements in c-MYB and MYBL1 in pediatric diffuse astrocytoma also provide candidates for therapeutic intervention. Targeting these molecularly identified pathways may allow for improved outcomes for patients as pediatric oncology moves into the era of biology-driven medicine.
Collapse
Affiliation(s)
- Eric Raabe
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Mark W. Kieran
- Dana-Farber/Children’s Hospital Cancer Center, Boston, Massachusetts
| | - Kenneth J. Cohen
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| |
Collapse
|