1
|
Zhang J, Zhou Y, Feng J, Xu X, Wu J, Guo C. Deciphering roles of TRIMs as promising targets in hepatocellular carcinoma: current advances and future directions. Biomed Pharmacother 2023; 167:115538. [PMID: 37729731 DOI: 10.1016/j.biopha.2023.115538] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/15/2023] [Accepted: 09/17/2023] [Indexed: 09/22/2023] Open
Abstract
Tripartite motif (TRIM) family is assigned to RING-finger-containing ligases harboring the largest number of proteins in E3 ubiquitin ligating enzymes. E3 ubiquitin ligases target the specific substrate for proteasomal degradation via the ubiquitin-proteasome system (UPS), which seems to be a more effective and direct strategy for tumor therapy. Recent advances have demonstrated that TRIM genes associate with the occurrence and progression of hepatocellular carcinoma (HCC). TRIMs trigger or inhibit multiple biological activities like proliferation, apoptosis, metastasis, ferroptosis and autophagy in HCC dependent on its highly conserved yet diverse structures. Remarkably, autophagy is another proteolytic pathway for intracellular protein degradation and TRIM proteins may help to delineate the interaction between the two proteolytic systems. In depth research on the precise molecular mechanisms of TRIM family will allow for targeting TRIM in HCC treatment. We also highlight several potential directions warranted further development associated with TRIM family to provide bright insight into its translational values in hepatocellular carcinoma.
Collapse
Affiliation(s)
- Jie Zhang
- Department of Gastroenterology, Putuo People's Hospital, Tongji University School of Medicine, Shanghai 200060, China; Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Yuting Zhou
- Department of Gastroenterology, Shanghai Tenth People's Hospital, School of Clinical Medicine of Nanjing Medical University, Shanghai 200072, China
| | - Jiao Feng
- Department of Gastroenterology, Putuo People's Hospital, Tongji University School of Medicine, Shanghai 200060, China; Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
| | - Xuanfu Xu
- Department of Gastroenterology, Shidong Hospital, University of Shanghai for Science and Technology, Shanghai 200433, China.
| | - Jianye Wu
- Department of Gastroenterology, Putuo People's Hospital, Tongji University School of Medicine, Shanghai 200060, China.
| | - Chuanyong Guo
- Department of Gastroenterology, Putuo People's Hospital, Tongji University School of Medicine, Shanghai 200060, China; Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
| |
Collapse
|
2
|
Lu K, Pan Y, Huang Z, Liang H, Ding ZY, Zhang B. TRIM proteins in hepatocellular carcinoma. J Biomed Sci 2022; 29:69. [PMID: 36100865 PMCID: PMC9469581 DOI: 10.1186/s12929-022-00854-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/02/2022] [Indexed: 11/19/2022] Open
Abstract
The tripartite motif (TRIM) protein family is a highly conserved group of E3 ligases with 77 members known in the human, most of which consist of a RING-finger domain, one or two B-box domains, and a coiled-coil domain. Generally, TRIM proteins function as E3 ligases to facilitate specific proteasomal degradation of target proteins. In addition, E3 ligase independent functions of TRIM protein were also reported. In hepatocellular carcinoma, expressions of TRIM proteins are both regulated by genetic and epigenetic mechanisms. TRIM proteins regulate multiple biological activities and signaling cascades. And TRIM proteins influence hallmarks of HCC. This review systematically demonstrates the versatile roles of TRIM proteins in HCC and helps us better understand the molecular mechanism of the development and progression of HCC.
Collapse
Affiliation(s)
- Kan Lu
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China
| | - Yonglong Pan
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China
| | - Zhao Huang
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China
- Key Laboratory of Organ Transplantation, Ministry of Education, Wuhan, China
- Key Laboratory of Organ Transplantation, National Health Commission, Wuhan, China
- Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, China
| | - Huifang Liang
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China
| | - Ze-Yang Ding
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China.
- Key Laboratory of Organ Transplantation, Ministry of Education, Wuhan, China.
- Key Laboratory of Organ Transplantation, National Health Commission, Wuhan, China.
- Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, China.
| | - Bixiang Zhang
- Hepatic Surgery Center, and Hubei Key Laboratory of Hepato-Pancreato-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
- Clinical Medical Research Center of Hepatic Surgery at Hubei Province, Wuhan, Hubei, China.
- Key Laboratory of Organ Transplantation, Ministry of Education, Wuhan, China.
- Key Laboratory of Organ Transplantation, National Health Commission, Wuhan, China.
- Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, China.
| |
Collapse
|
3
|
Zhao G, Liu C, Wen X, Luan G, Xie L, Guo X. The translational values of TRIM family in pan-cancers: From functions and mechanisms to clinics. Pharmacol Ther 2021; 227:107881. [PMID: 33930453 DOI: 10.1016/j.pharmthera.2021.107881] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 02/08/2023]
Abstract
Cancer is the second leading cause of human death across the world. Tripartite motif (TRIM) family, with E3 ubiquitin ligase activities in majority of its members, is reported to be involved in multiple cellular processes and signaling pathways. TRIM proteins have critical effects in the regulation of biological behaviors of cancer cells. Here, we discussed the current understanding of the molecular mechanism of TRIM proteins regulation of cancer cells. We also comprehensively reviewed published studies on TRIM family members as oncogenes or tumor suppressors in the oncogenesis, development, and progression of a variety of types of human cancers. Finally, we highlighted that certain TRIM family members are potential molecular biomarkers for cancer diagnosis and prognosis, and potential therapeutic targets.
Collapse
Affiliation(s)
- Guo Zhao
- Department of Preventive Medicine, Institute of Biomedical Informatics, Bioinformatics Center, Henan Provincial Engineering Center for Tumor Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Chuan Liu
- Department of Preventive Medicine, Institute of Biomedical Informatics, Bioinformatics Center, Henan Provincial Engineering Center for Tumor Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Xin Wen
- Department of Preventive Medicine, Institute of Biomedical Informatics, Bioinformatics Center, Henan Provincial Engineering Center for Tumor Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China
| | - Gan Luan
- Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Longxiang Xie
- Department of Preventive Medicine, Institute of Biomedical Informatics, Bioinformatics Center, Henan Provincial Engineering Center for Tumor Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China.
| | - Xiangqian Guo
- Department of Preventive Medicine, Institute of Biomedical Informatics, Bioinformatics Center, Henan Provincial Engineering Center for Tumor Molecular Medicine, School of Basic Medical Sciences, Henan University, Kaifeng 475004, China.
| |
Collapse
|
4
|
Chung YL, Wu ML. Dual oncogenic and tumor suppressor roles of the promyelocytic leukemia gene in hepatocarcinogenesis associated with hepatitis B virus surface antigen. Oncotarget 2016; 7:28393-407. [PMID: 27058621 PMCID: PMC5053734 DOI: 10.18632/oncotarget.8613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/18/2016] [Indexed: 12/25/2022] Open
Abstract
Proteasome-mediated degradation of promyelocytic leukemia tumor suppressor (PML) is upregulated in many viral infections and cancers. We previously showed that PML knockdown promotes early-onset hepatocellular carcinoma (HCC) in hepatitis B virus surface antigen (HBsAg)-transgenic mice. Here we report the effects of PML restoration on late-onset HBsAg-induced HCC. We compared protein expression patterns, genetic mutations and the effects of pharmacologically targeting PML in wild-type, PML-/-, PML+/+HBsAgtg/o and PML-/-HBsAgtg/o mice. PML-/- mice exhibited somatic mutations in DNA repair genes and developed severe steatosis and proliferative disorders, but not HCC. PML-/-HBsAgtg/o mice exhibited early mutations in cancer driver genes and developed hyperplasia, fatty livers and indolent adipose-like HCC. In PML+/+HBsAg-transgenic mice, HBsAg expression declined over time, and HBsAg-associated PML suppression was concomitantly relieved. Nevertheless, these mice accumulated mutations in genes contributing to oxidative stress pathways and developed aggressive late-onset angiogenic trabecular HCC. PML inhibition using non-toxic doses of arsenic trioxide selectively killed long-term HBsAg-affected liver cells in PML+/+HBsAgtg/o mice with falling HBsAg and rising PML levels, but not normal liver cells or early-onset HCC cells in PML-/-HBsAgtg/0 mice. These findings suggest dual roles for PML as a tumor-suppressor lost in early-onset HBsAg-induced hepatocarcinogenesis and as an oncogenic promoter in late-onset HBsAg-related HCC progression.
Collapse
Affiliation(s)
- Yih-Lin Chung
- Department of Radiation Oncology, Koo Foundation Sun-Yat-Sen Cancer Center, Taipei, Taiwan
| | - Mei-Ling Wu
- Department of Pathology and Laboratory Medicine, Koo Foundation Sun-Yat-Sen Cancer Center, Taipei, Taiwan
| |
Collapse
|
5
|
Kurinna S, Barton MC. Cascades of transcription regulation during liver regeneration. Int J Biochem Cell Biol 2011; 43:189-97. [PMID: 20307684 PMCID: PMC2923255 DOI: 10.1016/j.biocel.2010.03.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Revised: 01/13/2010] [Accepted: 03/15/2010] [Indexed: 01/20/2023]
Abstract
An increasing demand for new strategies in cancer prevention and regenerative medicine requires a better understanding of molecular mechanisms that control cell proliferation in tissue-specific manner. Regenerating liver is a unique model allowing use of biochemical, genetic, and engineering tools to uncover molecular mechanisms and improve treatment of hepatic cancers, liver failure, and fibrotic disease. Molecular mechanisms of liver regeneration involve extra- and intracellular factors to activate transcription of genes normally silenced in quiescent liver. While many upstream signaling pathways of the regenerating liver have been extensively studied, our knowledge of the downstream effectors, transcription factors (TFs), remains limited. This review describes consecutive engagement of pre-existing and de novo synthesized TFs, as cascades that regulate expression of growth-related and metabolic genes during liver regeneration after partial hepatectomy in mice. Several previously recognized regulators of regenerating liver are described in the light of recently identified co-activator and co-repressor complexes that interact with primary DNA-binding TFs. Published results of gene expression and chromatin immunoprecipitation analyses, as well as studies of transgenic mouse models, are used to emphasize new potential regulators of transcription during liver regeneration. Finally, a more detailed description of newly identified transcriptional regulators of liver regeneration illustrates the tightly regulated balance of proliferative and metabolic responses to partial hepatectomy.
Collapse
Affiliation(s)
- Svitlana Kurinna
- Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology, Graduate Program in Genes and Development, UT-Houston Graduate School of Biomedical Sciences, UT MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michelle Craig Barton
- Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology, Graduate Program in Genes and Development, UT-Houston Graduate School of Biomedical Sciences, UT MD Anderson Cancer Center, Houston, TX 77030, USA
| |
Collapse
|
6
|
Virador VM, Flores-Obando RE, Berry A, Patel R, Zakhari J, Lo YC, Strain K, Anders J, Cataisson C, Hansen LA, Yuspa SH. The human promyelocytic leukemia protein is a tumor suppressor for murine skin carcinogenesis. Mol Carcinog 2009; 48:599-609. [PMID: 19058256 PMCID: PMC2711034 DOI: 10.1002/mc.20498] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Expression of the PMLRARalpha fusion dominant-negative oncogene in the epidermis of transgenic mice resulted in spontaneous skin tumors attributed to changes in both the PML and RAR pathways [Hansen et al., Cancer Res 2003; 63:5257-5265]. To determine the contribution of PML to skin tumor susceptibility, transgenic mice were generated on an FVB/N background, that overexpressed the human PML protein in epidermis and hair follicles under the control of the bovine keratin 5 promoter. PML was highly expressed in the epidermis and hair follicles of these mice and was also increased in cultured keratinocytes where it was confined to nuclear bodies. While an overt skin phenotype was not detected in young transgenic mice, expression of keratin 10 (K10) was increased in epidermis and hair follicles and cultured keratinocytes. As mice aged, they exhibited extensive alopecia that was accentuated on the C57BL/6J background. Following skin tumor induction with 7, 12-dimethylbenz[a]anthracene (DMBA) as initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as promoter, papilloma multiplicity and size were decreased in the transgenic mice by 35%, and the conversion of papillomas to carcinomas was delayed. Cultured transgenic keratinocytes underwent premature senescence and upregulated transcripts for p16 and Rb but not p19 and p53. Together, these changes suggest that PML participates in regulating the growth and differentiation of keratinocytes that likely influence its activity as a suppressor for tumor development.
Collapse
Affiliation(s)
- Victoria M Virador
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research. National Cancer Institute, NIH, Bethesda, Maryland 20892-4255, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Sobol PT, Hummel JL, Rodrigues RM, Mossman KL. PML has a predictive role in tumor cell permissiveness to interferon-sensitive oncolytic viruses. Gene Ther 2009; 16:1077-87. [PMID: 19474810 DOI: 10.1038/gt.2009.68] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The oncotropic phenotypes of several viruses correlate with tumor-associated deficiencies within interferon (IFN) signaling pathways. This observation formed the conceptual basis for developing oncolytic viruses deleted for viral proteins that inhibit the host IFN-dependent antiviral response, such as herpes simplex virus type-1 infected cell protein-0 (ICP0) and vesicular stomatitis virus matrix protein. Many viruses have evolved means to disrupt promyelocytic leukemia protein (PML) nuclear bodies. For example, ICP0 promotes PML degradation to inhibit the antiviral activities of this IFN-stimulated gene. As PML is downregulated in a variety of tumors, we hypothesized ICP0-null herpes simplex type-1 viruses are selectively oncolytic in tumors with impaired PML expression. We illustrate that ICP0-null herpes simplex type-1 viruses target tumor cells that either possess impaired PML signaling or cannot upregulate PML because of impaired IFN responsiveness. Disruption of PML signaling through overexpression of the dominant-negative protein PML-retinoic acid receptor alpha in PML-positive cells renders them sensitive to oncolysis by ICP0-null herpes simplex virus type-1 and vesicular stomatitis virus M protein mutant viruses, whereas PML overexpression reverses this phenomenon. Together, these data illustrate that PML mediates an antiviral mechanism that predicts the tropism of IFN-sensitive oncolytic viruses. To our knowledge, these viruses are the first examples of anti-cancer therapeutics capable of targeting deficiencies in PML expression.
Collapse
Affiliation(s)
- P T Sobol
- Departments of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | | | | | | |
Collapse
|
8
|
Borden KLB. Pondering the puzzle of PML (promyelocytic leukemia) nuclear bodies: can we fit the pieces together using an RNA regulon? BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1783:2145-54. [PMID: 18616965 PMCID: PMC2652867 DOI: 10.1016/j.bbamcr.2008.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 06/03/2008] [Accepted: 06/10/2008] [Indexed: 12/26/2022]
Abstract
The promyelocytic leukemia protein PML and its associated nuclear bodies are hot topics of investigation. This interest arises for multiple reasons including the tight link between the integrity of PML nuclear bodies and several disease states and the impact of the PML protein and PML nuclear bodies on proliferation, apoptosis and viral infection. Unfortunately, an understanding of the molecular underpinnings of PML nuclear body function remains elusive. Here, a general overview of the PML field is provided and is extended to discuss whether some of the basic tenets of "PML-ology" are still valid. For instance, recent findings suggest that some components of PML nuclear bodies form bodies in the absence of the PML protein. Also, a new model for PML nuclear body function is proposed which provides a unifying framework for its effects on diverse biochemical pathways such as Akt signaling and the p53-Mdm2 axis. In this model, the PML protein acts as an inhibitor of gene expression post-transcriptionally via inhibiting a network node in the eIF4E RNA regulon. An example is given for how the PML RNA regulon model provided the basis for the development of a new anti-cancer strategy being tested in the clinic.
Collapse
Affiliation(s)
- Katherine L B Borden
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada H4M 1J6.
| |
Collapse
|
9
|
Kuwayama K, Matsuzaki K, Mizobuchi Y, Mure H, Kitazato KT, Kageji T, Nakao M, Nagahiro S. Promyelocytic leukemia protein induces apoptosis due to caspase-8 activation via the repression of NFkappaB activation in glioblastoma. Neuro Oncol 2008; 11:132-41. [PMID: 18812519 DOI: 10.1215/15228517-2008-083] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Promyelocytic leukemia (PML) protein plays an essential role in the induction of apoptosis; its expression is reduced in various cancers. As the functional roles of PML in glioblastoma multiforme (GBM) have not been clarified, we assessed the expression of PML protein in GBM tissues and explored the mechanisms of PML-regulated cell death in GBM cells. We examined the PML mRNA level and the expression of PML protein in surgical GBM specimens. PML-regulated apoptotic mechanisms in GBM cells transfected with plasmids expressing the PML gene were examined. The protein expression of PML was significantly lower in GBM than in non-neoplastic tissues; approximately 10% of GBM tissues were PML-null. The PML mRNA levels were similar in both tissue types. The overexpression of PML activated caspase-8 and induced apoptosis in GBM cells. In these cells, PML decreased the expression of transactivated forms of NFkappaB/p65, and c-FLIP gene expression was suppressed. Therefore, PML-induced apoptosis resulted from the suppression of the transcriptional activity of NFkappaB/p65. PML overexpression decreased phosphorylated IkappaBalpha and nuclear NFkappaB/p65 and increased the expression of the suppressor of cytokine signaling (SOCS-1). A proteasome inhibitor blocked the reduction of activated p65 by PML. The reduction of PML is associated with the pathogenesis of GBM. PML induces caspase-8-dependent apoptosis via the repression of NFkappaB activation by which PML facilitates the proteasomal degradation of activated p65 and the sequestration of p65 with IkappaBalpha in the cytoplasm. This novel mechanism of PML-regulated apoptosis may represent a therapeutic target for GBM.
Collapse
Affiliation(s)
- Kazuyuki Kuwayama
- Department of Neurosurgery, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Son SH, Yu E, Ahn Y, Choi EK, Lee H, Choi J. Retinoic acid attenuates promyelocytic leukemia protein-induced cell death in breast cancer cells by activation of the ubiquitin–proteasome pathway. Cancer Lett 2007; 247:213-23. [PMID: 16740359 DOI: 10.1016/j.canlet.2006.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 03/28/2006] [Accepted: 04/24/2006] [Indexed: 02/07/2023]
Abstract
All-trans-retinoic acid and the tumor suppressor promyelocytic leukemia protein (PML) are potent regulators of the growth of cancer cells. This study investigates the individual and combined effects of PML, when overexpressed by the recombinant PML adenovirus, and all-trans-retinoic acid on the proliferation of human estrogen-receptor negative SKBR-3 and estrogen-receptor positive MCF-7 breast cancer cell lines. All-trans-retinoic acid caused a significant degree of cell death in SKBR-3 cells and MCF-7 cells, and PML elicited a similar incidence of or slightly more cell death in MCF-7 cells. Dual-treated cells displayed significantly less cell death than did single-treated cells in the same cell line. We concluded that PML and all-trans-retinoic acid cause cell death by different pathways: PML activates ERK1/2, p38 MAPK, and p21; arrests the cell cycle; and later causes cell death; and all-trans-retinoic acid activates proteasome function, caspase cleavage, and apoptosis. The combined use of all-trans-retinoic acid and PML gene therapy may not be the best treatment for patients with cancer, because the ubiquitinylation of PML and its subsequent proteasome-dependent degradation by retinoic acids occur before overexpressed PML exhibits tumor-suppressive activity.
Collapse
Affiliation(s)
- Se-Hee Son
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | | | | | | | | | | |
Collapse
|