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Iglesias-Corral D, García-Valles P, Arroyo-Garrapucho N, Bueno-Martínez E, Ruiz-Robles JM, Ovejero-Sánchez M, González-Sarmiento R, Herrero AB. Chloroquine-induced DNA damage synergizes with DNA repair inhibitors causing cancer cell death. Front Oncol 2024; 14:1390518. [PMID: 38803536 PMCID: PMC11128598 DOI: 10.3389/fonc.2024.1390518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024] Open
Abstract
Background Cancer is a global health problem accounting for nearly one in six deaths worldwide. Conventional treatments together with new therapies have increased survival to this devastating disease. However, the persistent challenges of treatment resistance and the limited therapeutic arsenal available for specific cancer types still make research in new therapeutic strategies an urgent need. Methods Chloroquine was tested in combination with different drugs (Panobinostat, KU-57788 and NU-7026) in 8 human-derived cancer cells lines (colorectal: HCT116 and HT29; breast: MDA-MB-231 and HCC1937; glioblastoma: A-172 and LN-18; head and neck: CAL-33 and 32816). Drug´s effect on proliferation was tested by MTT assays and cell death was assessed by Anexin V-PI apoptosis assays. The presence of DNA double-strand breaks was analyzed by phospho-H2AX fluorescent staining. To measure homologous recombination efficiency the HR-GFP reporter was used, which allows flow cytometry-based detection of HR stimulated by I-SceI endonuclease-induced DSBs. Results The combination of chloroquine with any of the drugs employed displayed potent synergistic effects on apoptosis induction, with particularly pronounced efficacy observed in glioblastoma and head and neck cancer cell lines. We found that chloroquine produced DNA double strand breaks that depended on reactive oxygen species formation, whereas Panobinostat inhibited DNA double-strand breaks repair by homologous recombination. Cell death caused by chloroquine/Panobinostat combination were significantly reduced by N-Acetylcysteine, a reactive oxygen species scavenger, underscoring the pivotal role of DSB generation in CQ/LBH-induced lethality. Based on these data, we also explored the combination of CQ with KU-57788 and NU-7026, two inhibitors of the other main DSB repair pathway, nonhomologous end joining (NHEJ), and again synergistic effects on apoptosis induction were observed. Conclusion Our data provide a rationale for the clinical investigation of CQ in combination with DSB inhibitors for the treatment of different solid tumors.
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Affiliation(s)
- Diego Iglesias-Corral
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Paula García-Valles
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Nuria Arroyo-Garrapucho
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Elena Bueno-Martínez
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Juan Manuel Ruiz-Robles
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - María Ovejero-Sánchez
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Rogelio González-Sarmiento
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Ana Belén Herrero
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
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Wear D, Bhagirath E, Balachandar A, Vegh C, Pandey S. Autophagy Inhibition via Hydroxychloroquine or 3-Methyladenine Enhances Chemotherapy-Induced Apoptosis in Neuro-Blastoma and Glioblastoma. Int J Mol Sci 2023; 24:12052. [PMID: 37569432 PMCID: PMC10418453 DOI: 10.3390/ijms241512052] [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: 06/07/2023] [Revised: 07/14/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
Neuroblastoma is the most common tumour in children under 1 year old, accounting for 12-15% of childhood cancer deaths. Although current treatments are relatively efficacious against this cancer, associated adverse effects could be detrimental to growth and development. In contrast, glioblastoma accounts for 52% of brain tumours and has an extremely poor prognosis. Current chemotherapeutics include temozolomide, which has numerous negative side-effects and a low-effective rate. Previous studies have shown the manipulation of autophagy to be a promising method for targeting cancers, including glioblastoma. We sought to determine the effects of autophagic alterations in combination with current chemotherapies in both neuroblastoma and glioblastoma. Supplementing cisplatin or temozolomide with autophagy activator rapamycin stabilized cancer cell mitochondria, despite having little effect on apoptosis or oxidative stress. Autophagy inhibition via 3-methyladenine or hydroxychloroquine alongside standard chemotherapies enhanced apoptosis and oxidative stress, with 3-methyladenine also disrupting mitochondrial health. Importantly, combining hydroxychloroquine with 0.5 µM cisplatin or 50 µg/mL temozolomide was as or more effective than 2 µM cisplatin or 100 µg/mL temozolomide alone. Analyzing these interesting results, a combined treatment of autophagy inhibitor with a standard chemotherapeutic agent could help to improve patient prognosis and reduce chemotherapy doses and their associated side-effects.
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Affiliation(s)
- Darcy Wear
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; (D.W.); (E.B.); (A.B.); (C.V.)
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5R 0A3, Canada
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
| | - Eesha Bhagirath
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; (D.W.); (E.B.); (A.B.); (C.V.)
- Public Health, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 3K7, Canada
| | - Arpana Balachandar
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; (D.W.); (E.B.); (A.B.); (C.V.)
- Department of Medicine, University of Toronto, Toronto, ON M5R 0A3, Canada
| | - Caleb Vegh
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; (D.W.); (E.B.); (A.B.); (C.V.)
| | - Siyaram Pandey
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; (D.W.); (E.B.); (A.B.); (C.V.)
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Hai R, Yang D, Zheng F, Wang W, Han X, Bode AM, Luo X. The emerging roles of HDACs and their therapeutic implications in cancer. Eur J Pharmacol 2022; 931:175216. [PMID: 35988787 DOI: 10.1016/j.ejphar.2022.175216] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/03/2022] [Accepted: 08/12/2022] [Indexed: 12/25/2022]
Abstract
Deregulation of protein post-translational modifications is intensively involved in the etiology of diseases, including degenerative diseases, inflammatory injuries, and cancers. Acetylation is one of the most common post-translational modifications of proteins, and the acetylation levels are controlled by two mutually antagonistic enzyme families, histone acetyl transferases (HATs) and histone deacetylases (HDACs). HATs loosen the chromatin structure by neutralizing the positive charge of lysine residues of histones; whereas HDACs deacetylate certain histones, thus inhibiting gene transcription. Compared with HATs, HDACs have been more intensively studied, particularly regarding their clinical significance. HDACs extensively participate in the regulation of proliferation, migration, angiogenesis, immune escape, and therapeutic resistance of cancer cells, thus emerging as critical targets for clinical cancer therapy. Compared to HATs, inhibitors of HDAC have been clinically used for cancer treatment. Here, we enumerate and integratethe mechanisms of HDAC family members in tumorigenesis and cancer progression, and address the new and exciting therapeutic implications of single or combined HDAC inhibitor (HDACi) treatment.
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Affiliation(s)
- Rihan Hai
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Deyi Yang
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Feifei Zheng
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Weiqin Wang
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Xing Han
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA
| | - Xiangjian Luo
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China; Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China; Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, China; Key Laboratory of Biological Nanotechnology of National Health Commission, Central South University, Changsha, Hunan, 410078, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410078, China.
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Chloroquine-Induced DNA Damage Synergizes with Nonhomologous End Joining Inhibition to Cause Ovarian Cancer Cell Cytotoxicity. Int J Mol Sci 2022; 23:ijms23147518. [PMID: 35886866 PMCID: PMC9323666 DOI: 10.3390/ijms23147518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 12/04/2022] Open
Abstract
Ovarian cancer (OC) is the most lethal gynecological malignancy; therefore, more effective treatments are urgently needed. We recently reported that chloroquine (CQ) increased reactive oxygen species (ROS) in OC cell lines (OCCLs), causing DNA double-strand breaks (DSBs). Here, we analyzed whether these lesions are repaired by nonhomologous end joining (NHEJ), one of the main pathways involved in DSB repair, and if the combination of CQ with NHEJ inhibitors (NHEJi) could be effective against OC. We found that NHEJ inhibition increased the persistence of γH2AX foci after CQ-induced DNA damage, revealing an essential role of this pathway in the repair of the lesions. NHEJi decreased the proliferation of OCCLs and a strong in vitro synergistic effect on apoptosis induction was observed when combined with CQ. This effect was largely abolished by the antioxidant N-Acetyl-L-cysteine, revealing the critical role of ROS and DSB generation in CQ/NHEJi-induced lethality. We also found that the NHEJ efficiency in OCCLs was not affected by treatment with Panobinostat, a pan-histone deacetylase inhibitor that also synergizes with CQ in OCCLs by impairing homologous recombination. Accordingly, the triple combination of CQ-NHEJi-Panobinostat exerted a stronger in vitro synergistic effect. Altogether, our data suggest that the combination of these drugs could represent new therapeutic strategies against OC.
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Wang J, Wang K, Liang J, Jin J, Wang X, Yan S. Chitosan-tripolyphosphate nanoparticles-mediated co-delivery of MTHFD1L shRNA and 5-aminolevulinic acid for combination photodynamic-gene therapy in oral cancer. Photodiagnosis Photodyn Ther 2021; 36:102581. [PMID: 34648994 DOI: 10.1016/j.pdpdt.2021.102581] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/29/2021] [Accepted: 10/07/2021] [Indexed: 01/01/2023]
Abstract
BACKGROUND Rationally designed nanostructured materials can produce improved drug carriers that play an increasingly important role in cancer treatment. In comparison with conventional drug combination approaches, using co-delivery systems of multiple drugs achieves sophisticated targeting strategies and multifunctionality. METHODS First, a nano-co-delivery of chitosan/tripolyphosphate (CS-TPP) was synthesized and characterized combining 5-aminolevulinic acid photodynamic therapy (ALA-PDT) with methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L) shRNA. In this report, we investigated the efficacy of the simultaneous delivery of shRNA/photosensitizer on the gene expression of oral squamous cell carcinoma (OSCC) cells. The efficacy of CS-TPP-(shMTHFD1L-ALA)-PDT in inducing apoptosis and in generating of reactive oxygen species (ROS) in vitro was then assessed by Annexin V-PI and DCFH-DA assays respectively. In vivo therapeutic experiments were conducted in well-established orthotopic animal models of HNSCC. RESULTS The results showed that the CS-TPP-(shMTHFD1L-ALA) nanoparticles (NPs) were approximately 145 nm in size. The cytotoxicity of OSCC cells was significantly increased by co-delivery of MTHFD1L shRNA and ALA-PDT compared with other groups. Furthermore, individual and combined therapies revealed remarkable pro-apoptotic, ROS and anti-tumorigenesis effects, and CS-TPP-(shMTHFD1L-ALA)-PDT had additive effects in vitro and in vivo. CONCLUSION These observations indicate that CS-TPP-(shMTHFD1L-ALA) NPs may be an ideal candidate for gene/photosensitizer delivery.
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Affiliation(s)
- Jian Wang
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, 100101, China
| | - Ke Wang
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, 100101, China
| | - Jin Liang
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, 100101, China
| | - Jianqiu Jin
- Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100100, China
| | - Xing Wang
- Foshan (Southern China) Institute for New Materials, Foshan, 528220, China.
| | - Shu Yan
- Department of Stomatology, PLA Strategic Support Force Medical Center, Beijing, 100101, China; PLA 306 Clinical College of Anhui Medical University, Hefei, 230001, China.
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Li Y, Yang G, Yang C, Tang P, Chen J, Zhang J, Liu J, Ouyang L. Targeting Autophagy-Related Epigenetic Regulators for Cancer Drug Discovery. J Med Chem 2021; 64:11798-11815. [PMID: 34378389 DOI: 10.1021/acs.jmedchem.1c00579] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Existing evidence has demonstrated that epigenetic modifications (including DNA methylation, histone modifications, and microRNAs), which are associated with the occurrence and development of tumors, can directly or indirectly regulate autophagy. In particular, nuclear events induced by several epigenetic regulators can regulate the autophagic process and expression levels of tumor-associated genes, thereby promoting tumor progression. Tumor-associated microRNAs, including oncogenic and tumor-suppressive microRNAs, are of great significance to autophagy during tumor progression. Targeting autophagy with emerging epigenetic drugs is expected to be a promising therapeutic strategy for human tumors. From this perspective, we aim to summarize the role of epigenetic modification in the autophagic process and the underlying molecular mechanisms of tumorigenesis. Furthermore, the regulatory efficacy of epigenetic drugs on the autophagic process in tumors is also summarized. This perspective may provide a theoretical basis for the combined treatment of epigenetic drugs/autophagy mediators in tumors.
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Affiliation(s)
- Yang Li
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Gaoxia Yang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Chengcan Yang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Pan Tang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Juncheng Chen
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Jifa Zhang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Jie Liu
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
| | - Liang Ouyang
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China
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Kommalapati VK, Kumar D, Tangutur AD. Quisinostat mediated autophagy is associated with differentiation in neuroblastoma SK-N-SH cells. Mol Biol Rep 2021; 48:4973-4979. [PMID: 34125328 DOI: 10.1007/s11033-021-06481-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/05/2021] [Indexed: 01/18/2023]
Abstract
Neuroblastoma (NB) is the most common childhood cancer that arises from the sympathetic nervous system. NB is characterized by poor prognosis. One of the strategies to control NB is activating the differentiation process in undifferentiated NB cells. Many differentiating agents including 13-cis-retinoic acid (RA) led to disappointing results. In the current study, we investigated the effect of Quisinostat/JNJ-26481585(JNJ) on NB SK-N-SH cells differentiation. The SK-N-SH cell differentiation was observed by morphology and neurite length measurement. The cell cycle arrest was determined by FACS analysis. The relative levels of autophagy marker LC3-II, neuronal markers βIII-tubulin and Eno-2, cell cycle related proteins cyclin D1 and CDK 4 were detected by western blotting. JNJ induces differentiation in SK-N-SH cells, as evident by the morphological features and expression of neuronal markers, βIII-tubulin and Eno-2. Cell cycle arrest at G1 phase was confirmed by a decrease in the expression of cyclin D1 and CDK 4. Furthermore, we also observed that autophagy plays an important role in JNJ induced cell differentiation of SK-N-SH cells. We demonstrated that autophagy is induced upon JNJ treatment and is important for the neuronal differentiation of human SK-N-SH cells.
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Affiliation(s)
- Vamsi Krishna Kommalapati
- Department of Applied Biology, CSIR- Indian Institute of Chemical Technology, Hyderabad, 500007, Telangana, India
- Academy of Scientific and Innovative Research, Ghaziabad, 201002, Uttar Pradesh, India
| | - Dinesh Kumar
- Department of Applied Biology, CSIR- Indian Institute of Chemical Technology, Hyderabad, 500007, Telangana, India
- Academy of Scientific and Innovative Research, Ghaziabad, 201002, Uttar Pradesh, India
| | - Anjana Devi Tangutur
- Department of Applied Biology, CSIR- Indian Institute of Chemical Technology, Hyderabad, 500007, Telangana, India.
- Academy of Scientific and Innovative Research, Ghaziabad, 201002, Uttar Pradesh, India.
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Ovejero-Sánchez M, González-Sarmiento R, Herrero AB. Synergistic effect of Chloroquine and Panobinostat in ovarian cancer through induction of DNA damage and inhibition of DNA repair. Neoplasia 2021; 23:515-528. [PMID: 33930758 PMCID: PMC8100353 DOI: 10.1016/j.neo.2021.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 12/24/2022]
Abstract
Ovarian cancer (OC) is the deadliest gynecologic malignancy, which is mainly due to late-stage diagnosis and chemotherapy resistance. Therefore, new and more effective treatments are urgently needed. The in vitro effects of Panobinostat (LBH), a histone deacetylase inhibitor that exerts pleiotropic antitumor effects but induces autophagy, in combination with Chloroquine (CQ), an autophagy inhibitor that avoid this cell survival mechanism, were evaluated in 4 OC cell lines. LBH and CQ inhibited ovarian cancer cell proliferation and induced apoptosis, and a strong synergistic effect was observed when combined. Deeping into their mechanisms of action we show that, in addition to autophagy modulation, treatment with CQ increased reactive oxygen species (ROS) causing DNA double strand breaks (DSBs), whereas LBH inhibited their repair by avoiding the correct recruitment of the recombinase Rad51 to DSBs. Interestingly, CQ-induced DSBs and cell death caused by CQ/LBH combination were largely abolished by the ROS scavenger N-Acetylcysteine, revealing the critical role of DSB generation in CQ/LBH-induced lethality. This role was also manifested by the synergy found when we combined CQ with Mirin, a well-known homologous recombination repair inhibitor. Altogether, our results provide a rationale for the clinical investigation of CQ/LBH combination in ovarian cancer.
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Affiliation(s)
- María Ovejero-Sánchez
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain; Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain; Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain
| | - Rogelio González-Sarmiento
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain; Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain; Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain.
| | - Ana Belén Herrero
- Institute of Biomedical Research of Salamanca (IBSAL), Salamanca, Spain; Molecular Medicine Unit, Department of Medicine, University of Salamanca, Salamanca, Spain; Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-CSIC, Salamanca, Spain.
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