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Ma Z, Ma Y, Feng J, Xu Z, Cheng C, Qin J, Li S, Jiang J, Kong R. NDRG2 acts as a negative regulator of the progression of small-cell lung cancer through the modulation of the PTEN-AKT-mTOR signalling cascade. Toxicol Appl Pharmacol 2024; 485:116915. [PMID: 38537875 DOI: 10.1016/j.taap.2024.116915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 03/20/2024] [Accepted: 03/24/2024] [Indexed: 04/08/2024]
Abstract
N-myc downstream-regulated gene 2 (NDRG2) has been recognised as a negative regulator of the progression of numerous tumours, yet its specific role in small-cell lung carcinoma (SCLC) is not fully understood. The purpose of the current study was to investigate the biological role and mechanism of NDRG2 in SCLC. Initial investigation using the Gene Expression Omnibus (GEO) dataset revealed marked downregulation of NDRG2 transcripts in SCLC. The decreased abundance of NDRG2 in SCLC was verified by examining clinical specimens. Increasing NDRG2 expression in SCLC cell lines caused significant changes in cell proliferation, cell cycle progression, colony formation, and chemosensitivity. NDRG2 overexpression decreased the levels of phosphorylated PTEN, AKT and mTOR. In PTEN-depleted SCLC cells, the upregulation of NDRG2 did not result in any noticeable impact on AKT or mTOR activation. Additionally, the reactivation of AKT reversed the antitumour effects of NDRG2 in SCLC cells. Notably, increasing NDRG2 expression retarded the growth of SCLC cell-derived xenografts in vivo. In conclusion, NDRG2 serves as an inhibitor of SCLC, and its cancer-inhibiting effects are achieved through the suppression of AKT/mTOR via the activation of PTEN. This work suggests that NDRG2 is a potential druggable target for SCLC treatment.
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Affiliation(s)
- Zhenchuan Ma
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Yuefeng Ma
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Jie Feng
- Department of Nephrology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Zhengshui Xu
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Chuantao Cheng
- Department of Dermatology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Jie Qin
- Department of Orthopedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Shaomin Li
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Jiantao Jiang
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
| | - Ranran Kong
- Department of Thoracic Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
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Goris M, Jacobsen RG, Lewis AE. Presence of active AKT in the nucleus upon adipocyte differentiation of 3T3-L1 cells. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001140. [PMID: 38495585 PMCID: PMC10940900 DOI: 10.17912/micropub.biology.001140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/14/2024] [Accepted: 02/25/2024] [Indexed: 03/19/2024]
Abstract
AKT is an essential player in the phosphoinositide 3-kinase (PI3K) signalling pathway. Although the mechanisms of its action are well understood at the plasma membrane, AKT can also be found in the nucleus. In adipocytes, this pathway is activated during the process of adipogenesis and solicits both plasma membrane and nuclear AKT activity. However, the endogenous presence of active AKT in the nucleus during adipogenesis has not been shown. Here, we show that the levels of active AKT phosphorylated at Ser-473 increase rapidly after the induction of differentiation in 3T3-L1 cells, both in the cytoplasm and in the nucleus, and tend to remain elevated over the course of differentiation. In conclusion, these results support the notion that nuclear AKT plays an important role in this process.
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Affiliation(s)
- Marianne Goris
- Department of Biological Sciences, University of Bergen, Bergen, Vestland, Norway
| | - Rhîan G. Jacobsen
- Department of Biological Sciences, University of Bergen, Bergen, Vestland, Norway
| | - Aurélia E. Lewis
- Department of Biological Sciences, University of Bergen, Bergen, Vestland, Norway
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Xu X, Hou D, Wang Y, Zhang J, Hei Y, Wang B, Tian S, Zhang Y, Wang F. Knockdown of NF-κB activating protein promotes pancreatic cancer growth and metastasis through mTOR signaling pathway. Mol Biol Rep 2023; 50:7501-7513. [PMID: 37486443 DOI: 10.1007/s11033-023-08665-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023]
Abstract
BACKGROUND NF-κB activating protein (NKAP) acts as a transcriptional suppressor in the Notch signaling pathway, It plays a role in hematopoiesis maintenance, immune cell development, maturation, and functional competency acquisition. NKAP has been found to act as an oncogene in many tumors, but it has not been reported in PAAD.The purpose of this study was to investigate the effect of NKAP on the growth and metastasis of pancreatic adenocarcinoma(PAAD). METHODS AND RESULTS In this study, western blot and qRT-PCR showed that highly expressed NKAP was found in PAAD cell lines, and small interfering RNA (siRNA) was employed to reduce the expression of NKAP in PAAD cell lines. The results of CCK-8, clony formation, Transwell and flow cytometry showed that knockdown of NKAP significantly inhibited biological function of PAAD cells, and increased cell apoptosis. Study also observed that knockdown of NKAP inhibited the expression levels of apoptosis proteins and cyclin in PAAD cells. In addition, mTOR's degree of phosphorylation and the expression of its downstream target p70S6K can both be activated by NKAP. This effect was also confirmed in salvage experiments performed with Rapamycin(RaPa), an inhibitor of mTOR. At the end of the experiment, It was investigated how NKAP affected the drug sensitivity of gemcitabine used to treat PAAD. The results showed that knocking down NKAP could increase the drug sensitivity of gemcitabine. CONCLUSIONS NKAP as an oncogene regulates the development of PAAD cells. The research found that the mTOR signaling pathway is engaged in the oncogenic role of NKAP in PAAD for the first time.
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Affiliation(s)
- Xiangrong Xu
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Danyang Hou
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Yujie Wang
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Jing Zhang
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Yu Hei
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Bobo Wang
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Shuyue Tian
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China
| | - Yunqing Zhang
- Laboratory of Obstetrics and Gynecology, Affiliated Hospital of Yan'an University, Yan'an, Shaanxi Province, 716000, China
| | - Fenghui Wang
- Medical Research and Experimental Center, Medical College, Yan'an University, Yan'an, 716000, People's Republic of China.
- Yan'an Key Laboratory of Fungal Resources Development and Biological Control, Yan'an, Shaanxi Province, 716000, China.
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Ma Z, Ding J, Wang Y, Zhang T, Chen G, Huang J. Study of platelet-rich fibrin promoting endothelial cell differentiation and angiogenesis induced by transplantation of adipose-derived stem cells. Acta Histochem 2023; 125:152059. [PMID: 37329849 DOI: 10.1016/j.acthis.2023.152059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 06/04/2023] [Accepted: 06/04/2023] [Indexed: 06/19/2023]
Abstract
Diabetic patients are characterized by long wound healing time, and adipose stem cells (ADSCs) can secrete growth factors to promote angiogenesis and improve diabetic wound healing. In this research, we attempted to interrogate the impact of platelet-rich fibrin (PRF) on ADSCs in diabetic wound healing. ADSCs were harvested from human adipose tissues and identified through flow cytometry. After pretreatment with cultured medium supplemented with different concentrations of PRF (2.5%, 5%, and 7.5%), proliferation and differentiation capacity of ADSCs were assessed by CCK-8 assay, qRT-PCR and immunofluorescence (IF), respectively. Tube formation assay measured angiogenesis. Western blot analysis analyzed expression of endothelial markers and the extracellular signal-regulated kinase (ERK) and serine/threonine kinase (Akt) pathways in PRF-induced ADSCs. The CCK-8 experiment indicated that PRF enhanced proliferation of ADSCs in dose-dependent manner, relative to normal control group. The expression of endothelial markers and the capacity of tube formation were significantly promoted by 7.5% PRF. The release of growth factors containing vascular endothelial grow factor (VEGF) and insulin-like growth factor-1 (IGF-1) from PRF was increased with the extension of detection time. When the receptors of VEGF or/and IGF-1 were neutralized, ADSCs differentiation into endothelial cells were obviously inhibited. Additionally, PRF stimulated ERK and Akt pathways, and the inhibitors of ERK and Akt attenuated PRF-induced differentiation of ADSCs into endothelial cells. In conclusion, PRF promoted endothelial cell differentiation and angiogenesis induced by ADSCs in diabetic wound healing, which appears to give guidance for treating patients.
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Affiliation(s)
- Zhibing Ma
- Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210000, People's Republic of China
| | - Jin Ding
- Department of Pathology, Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210000, People's Republic of China
| | - Yawen Wang
- Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210000, People's Republic of China
| | - Tianqi Zhang
- Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210000, People's Republic of China
| | - Gang Chen
- Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210000, People's Republic of China
| | - Jinlong Huang
- Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210000, People's Republic of China.
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Ahmad Hairi H, Jayusman PA, Shuid AN. Revisiting Resveratrol as an Osteoprotective Agent: Molecular Evidence from In Vivo and In Vitro Studies. Biomedicines 2023; 11:1453. [PMID: 37239124 PMCID: PMC10216404 DOI: 10.3390/biomedicines11051453] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Resveratrol (RSV) (3,5,4'-trihydroxystilbene) is a stilbene found in abundance in berry fruits, peanuts, and some medicinal plants. It has a diverse range of pharmacological activities, underlining the significance of illness prevention and health promotion. The purpose of this review was to delve deeper into RSV's bone-protective properties as well as its molecular mechanisms. Several in vivo studies have found the bone-protective effects of RSV in postmenopausal, senile, and disuse osteoporosis rat models. RSV has been shown to inhibit NF-κB and RANKL-mediated osteoclastogenesis, oxidative stress, and inflammation while increasing osteogenesis and boosting differentiation of mesenchymal stem cells to osteoblasts. Wnt/β-catenin, MAPKs/JNK/ERK, PI3K/AKT, FoxOs, microRNAs, and BMP2 are among the possible kinases and proteins involved in the underlying mechanisms. RSV has also been shown to be the most potent SIRT1 activator to cause stimulatory effects on osteoblasts and inhibitory effects on osteoclasts. RSV may, thus, represent a novel therapeutic strategy for increasing bone growth and reducing bone loss in the elderly and postmenopausal population.
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Affiliation(s)
- Haryati Ahmad Hairi
- Department of Biochemistry, Faculty of Medicine, Manipal University College Malaysia, Jalan Batu Hampar, Bukit Baru, Melaka 75150, Malaysia;
| | - Putri Ayu Jayusman
- Department of Craniofacial Diagnostics and Biosciences, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia;
| | - Ahmad Nazrun Shuid
- Department of Pharmacology, Faculty of Medicine, Universiti Teknologi Mara (UITM), Jalan Hospital, Sungai Buloh 47000, Malaysia
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Pietrus M, Pitynski K, Waligora M, Milian-Ciesielska K, Ludwin A, Socha MW, Skrzypek K. Association of Membranous WNT-1 and Nuclear mTOR with Endometrial Cancer Grade. Int J Mol Sci 2023; 24:ijms24098342. [PMID: 37176048 PMCID: PMC10179139 DOI: 10.3390/ijms24098342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/29/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Endometrial cancer remains a common cancer affecting the female reproductive system. There is still a need for more efficient ways of determining the degree of malignancy and optimizing treatment. WNT and mTOR are components of signaling pathways within tumor cells, and dysfunction of either protein is associated with the pathogenesis of neoplasms. Therefore, the aim of our study was to assess the impact of subcellular WNT-1 and mTOR levels on the clinical course of endometrial cancer. WNT-1 and mTOR levels in the plasma membrane, nucleus, and cytoplasm were evaluated using immunohistochemical staining in a group of 64 patients with endometrial cancer of grades 1-3 and FIGO stages I-IV. We discovered that the levels of WNT-1 and mTOR expression in the cellular compartments were associated with tumor grade and staging. Membranous WNT-1 was negatively associated, whereas cytoplasmic WNT-1 and nuclear mTOR were positively associated with higher grading of endometrial cancer. Furthermore, nuclear mTOR was positively associated with FIGO stages IB-IV. To conclude, we found that the assessment of WNT-1 in the cell membrane may be useful for exclusion of grade 3 neoplasms, whereas cytoplasmic WNT-1 and nuclear mTOR may be used as indicators for confirmation of grade 3 neoplasms.
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Affiliation(s)
- Milosz Pietrus
- Department of Gynecology and Oncology, Faculty of Medicine, Jagiellonian University Medical College, 31-501 Krakow, Poland
| | - Kazimierz Pitynski
- Department of Gynecology and Oncology, Faculty of Medicine, Jagiellonian University Medical College, 31-501 Krakow, Poland
| | - Marcin Waligora
- Pulmonary Circulation Centre, Department of Cardiac and Vascular Diseases, Faculty of Medicine, Jagiellonian University Medical College, John Paul II Hospital in Krakow, 31-022 Krakow, Poland
- Center for Innovative Medical Education, Department of Medical Education, Faculty of Medicine, Jagiellonian University Medical College, 30-688 Krakow, Poland
| | - Katarzyna Milian-Ciesielska
- Department of Pathomorphology, Faculty of Medicine, Jagiellonian University Medical College, 31-531 Krakow, Poland
| | - Artur Ludwin
- Department of Gynecology and Oncology, Faculty of Medicine, Jagiellonian University Medical College, 31-501 Krakow, Poland
| | - Maciej W Socha
- Department of Perinatology, Gynecology and Gynecologic Oncology, Faculty of Health Sciences, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, 85-821 Bydgoszcz, Poland
| | - Klaudia Skrzypek
- Department of Transplantation, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University Medical College, 30-663 Krakow, Poland
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Langdon CG. Nuclear PTEN's Functions in Suppressing Tumorigenesis: Implications for Rare Cancers. Biomolecules 2023; 13:biom13020259. [PMID: 36830628 PMCID: PMC9953540 DOI: 10.3390/biom13020259] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/25/2023] [Accepted: 01/28/2023] [Indexed: 01/31/2023] Open
Abstract
Phosphatase and tensin homolog (PTEN) encodes a tumor-suppressive phosphatase with both lipid and protein phosphatase activity. The tumor-suppressive functions of PTEN are lost through a variety of mechanisms across a wide spectrum of human malignancies, including several rare cancers that affect pediatric and adult populations. Originally discovered and characterized as a negative regulator of the cytoplasmic, pro-oncogenic phosphoinositide-3-kinase (PI3K) pathway, PTEN is also localized to the nucleus where it can exert tumor-suppressive functions in a PI3K pathway-independent manner. Cancers can usurp the tumor-suppressive functions of PTEN to promote oncogenesis by disrupting homeostatic subcellular PTEN localization. The objective of this review is to describe the changes seen in PTEN subcellular localization during tumorigenesis, how PTEN enters the nucleus, and the spectrum of impacts and consequences arising from disrupted PTEN nuclear localization on tumor promotion. This review will highlight the immediate need in understanding not only the cytoplasmic but also the nuclear functions of PTEN to gain more complete insights into how important PTEN is in preventing human cancers.
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Affiliation(s)
- Casey G. Langdon
- Department of Pediatrics, Darby Children’s Research Institute, Medical University of South Carolina, Charleston, SC 29425, USA; ; Tel.: +1-(843)-792-9289
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
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de la Torre C, Játiva P, Posadas I, Manzanares D, Blanco JLJ, Mellet CO, Fernández JMG, Ceña V. A β-Cyclodextrin-Based Nanoparticle with Very High Transfection Efficiency Unveils siRNA-Activated TLR3 Responses in Human Prostate Cancer Cells. Pharmaceutics 2022; 14:2424. [PMID: 36365241 PMCID: PMC9692777 DOI: 10.3390/pharmaceutics14112424] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 10/18/2023] Open
Abstract
Synthetic double-stranded small interfering RNAs (siRNAs) mimic interference RNAs (RNAi) and can bind target mRNAs with a high degree of specificity, leading to selective knockdown of the proteins they encode. However, siRNAs are very labile and must be both protected and transported by nanoparticles to be efficiently delivered into cells. In this work, we used a Janus-type polycationic amphiphilic β-cyclodextrin derivative to efficiently transfect siRNAs targeting mRNAs encoding mitogen-activated protein kinase (p42-MAPK) or Ras homolog enriched in brain (Rheb) into different cancer cell lines as well as astrocytes. We took advantage of this high transfection efficiency to simultaneously knock down p42-MAPK and Rheb to boost docetaxel (DTX)-mediated toxicity in two human prostate cancer cell lines (LNCaP and PC3). We found that double knockdown of p42-MAPK and Rheb increased DTX-toxicity in LNCaP but not in PC3 cells. However, we also observed the same effect when scramble siRNA was used, therefore pointing to an off-target effect. Indeed, we found that the siRNA we used in this work induced toll-like receptor 3 activation, leading to β-interferon production and caspase activation. We believe that this mechanism could be very useful as a general strategy to elicit an immune response against prostate cancer cells.
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Affiliation(s)
- Cristina de la Torre
- Unidad Asociada Neurodeath, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
- Centro de Investigación Biomédica En Red (CIBER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Játiva
- Unidad Asociada Neurodeath, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
- Centro de Investigación Biomédica En Red (CIBER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Inmaculada Posadas
- Unidad Asociada Neurodeath, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
- Centro de Investigación Biomédica En Red (CIBER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Darío Manzanares
- Unidad Asociada Neurodeath, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
- Centro de Investigación Biomédica En Red (CIBER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José L. Jiménez Blanco
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Carmen Ortiz Mellet
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain
| | | | - Valentín Ceña
- Unidad Asociada Neurodeath, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
- Centro de Investigación Biomédica En Red (CIBER), Instituto de Salud Carlos III, 28029 Madrid, Spain
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Pei X, Mladenov E, Soni A, Li F, Stuschke M, Iliakis G. PTEN Loss Enhances Error-Prone DSB Processing and Tumor Cell Radiosensitivity by Suppressing RAD51 Expression and Homologous Recombination. Int J Mol Sci 2022; 23:12876. [PMID: 36361678 PMCID: PMC9658850 DOI: 10.3390/ijms232112876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 09/29/2023] Open
Abstract
PTEN has been implicated in the repair of DNA double-strand breaks (DSBs), particularly through homologous recombination (HR). However, other data fail to demonstrate a direct role of PTEN in DSB repair. Therefore, here, we report experiments designed to further investigate the role of PTEN in DSB repair. We emphasize the consequences of PTEN loss in the engagement of the four DSB repair pathways-classical non-homologous end-joining (c-NHEJ), HR, alternative end-joining (alt-EJ) and single strand annealing (SSA)-and analyze the resulting dynamic changes in their utilization. We quantitate the effect of PTEN knockdown on cell radiosensitivity to killing, as well as checkpoint responses in normal and tumor cell lines. We find that disruption of PTEN sensitizes cells to ionizing radiation (IR). This radiosensitization is associated with a reduction in RAD51 expression that compromises HR and causes a marked increase in SSA engagement, an error-prone DSB repair pathway, while alt-EJ and c-NHEJ remain unchanged after PTEN knockdown. The G2-checkpoint is partially suppressed after PTEN knockdown, corroborating the associated HR suppression. Notably, PTEN deficiency radiosensitizes cells to PARP inhibitors, Olaparib and BMN673. The results show the crucial role of PTEN in DSB repair and show a molecular link between PTEN and HR through the regulation of RAD51 expression. The expected benefit from combination treatment with Olaparib or BMN673 and IR shows that PTEN status may also be useful for patient stratification in clinical treatment protocols combining IR with PARP inhibitors.
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Affiliation(s)
- Xile Pei
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Emil Mladenov
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Aashish Soni
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Fanghua Li
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Martin Stuschke
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, 45147 Essen, Germany
| | - George Iliakis
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
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