1
|
Feng Y, Jiang Y, Liu J, Liu J, Shi M, Chen J, Zhang J, Tian Y, Yang X, Liu H. Targeting RPA promotes autophagic flux and the antitumor response to radiation in nasopharyngeal carcinoma. J Transl Med 2023; 21:738. [PMID: 37858134 PMCID: PMC10585929 DOI: 10.1186/s12967-023-04574-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 05/25/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Autophagy is involved in nasopharyngeal carcinoma (NPC) radioresistance. Replication protein A 1 (RPA1) and RPA3, substrates of the RPA complex, are potential therapeutic targets for reversing NPC radioresistance. Nevertheless, the role of RPA in autophagy is not adequately understood. This investigation was performed to reveal the cytotoxic mechanism of a pharmacologic RPA inhibitor (RPAi) in NPC cells and the underlying mechanism by which RPAi-mediated autophagy regulates NPC radiosensitivity. METHODS AND RESULTS We characterized a potent RPAi (HAMNO) that was substantially correlated with radiosensitivity enhancement and proliferative inhibition of in vivo and in NPC cell lines in vitro. We show that the RPAi induced autophagy at multiple levels by inducing autophagic flux, AMPK/mTOR pathway activation, and autophagy-related gene transcription by decreasing glycolytic function. We hypothesized that RPA inhibition impaired glycolysis and increased NPC dependence on autophagy. We further demonstrated that combining autophagy inhibition with chloroquine (CQ) treatment or genetic inhibition of the autophagy regulator ATG5 and RPAi treatment was more effective than either approach alone in enhancing the antitumor response of NPC to radiation. CONCLUSIONS Our study suggests that HAMNO is a potent RPAi that enhances radiosensitivity and induces autophagy in NPC cell lines by decreasing glycolytic function and activating autophagy-related genes. We suggest a novel treatment strategy in which pharmacological inhibitors that simultaneously disrupt RPA and autophagic processes improve NPC responsiveness to radiation.
Collapse
Affiliation(s)
- Yanchun Feng
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Yingming Jiang
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Department of General Surgery (Department of Gastric Surgery Section 2, ), The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jun Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jiaqi Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Mengchen Shi
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Junxiong Chen
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jingdan Zhang
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Yu Tian
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Xiangling Yang
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China.
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
| | - Huanliang Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China.
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
| |
Collapse
|
2
|
Zhang Z, Huo H, Liao K, Wang Z, Gong Z, Li Y, Liu C, Hu G. RPA1 downregulation enhances nasopharyngeal cancer radiosensitivity via blocking RAD51 to the DNA damage site. Exp Cell Res 2018; 371:330-341. [PMID: 30144445 DOI: 10.1016/j.yexcr.2018.08.025] [Citation(s) in RCA: 11] [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] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/01/2018] [Accepted: 08/21/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND/AIM Nasopharyngeal cancer (NPC) has a high local recurrence rate due to its resistance to ionizing radiation (IR). Replication protein A1 (RPA1) is one of the main elements in the homologous repair (HR) pathway, which is closely associated with the repair of DNA double strand breaks (DDBs). Studies on the relationship between RPA1 and the radiosensitivity of NPC are substantially limited. It was hypothesized that RPA1 plays a crucial role in predicting the radiosensitivity of NPC. METHODS The protein expression of RPA1 in 182 patients with NPC in the complete response (CR) and non-complete response (nCR) groups was evaluated using immunohistochemistry. Then, univariate and multivariate analysis were performed using SPSS software vision 22 to determine the relationship between the expression of RPA1 and the clinicopathological features. In addition, the mRNA expression of RPA1 was tested in 24 fresh samples using qRT-PCR. RPA1 was silenced in CNE-2R cell lines combined with IR to measure the radiosensitivity, proliferation, DNA damage repair and cell cycle of CNE-2R cells. Xenograft models in nude mice were used to determine the effect of RPA1 on tumor growth after IR. Immunoblotting and immunofluorescence staining were performed to identify proteins that interacted with RPA1. All statistical tests were two-sided. RESULTS RPA1 protein was overexpressed in NPC patients with nCR (65.31%), and was an independent predictor of radiosensitivity (HR: 3.755, 95% CI: 1.990-7.085), in addition to Epstein-Barr virus (EBV; HR: 3.984; 95% CI: 1.524-10.410). The silencing of RPA1 increased the radiosensitivity of CNE-2R cells, blocked the repair of DNA, impaired cell proliferation, and contributed to G2/M cell cycle arrest. Furthermore, the xenograft models in nude mice revealed that silencing RPA1 combined with irradiation significantly retarded the growth of tumors. Moreover, the knockdown of RPA1 decreased Rad51 collection to the damage site and prolonged the time of DNA repair. CONCLUSION RPA1 protein is frequently overexpressed in NPC patients with nCR. The silencing of RPA1 enhanced the radiosensitivity of CNE-2R cells. These present findings reveal that RPA1 is a potential biomarker for predicting the radiosensitivity in NPC.
Collapse
Affiliation(s)
- Zixin Zhang
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China; Department of Radiotherapy, the General Hospital of Ningxia Medical University, Yinchuan 750004, China
| | - Haifeng Huo
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Kui Liao
- Department of Oncology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhihai Wang
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhitao Gong
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yanshi Li
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Chuan Liu
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Guohua Hu
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| |
Collapse
|
3
|
Mateos-Gomez PA, Kent T, Deng SK, McDevitt S, Kashkina E, Hoang TM, Pomerantz RT, Sfeir A. The helicase domain of Polθ counteracts RPA to promote alt-NHEJ. Nat Struct Mol Biol 2017; 24:1116-1123. [PMID: 29058711 PMCID: PMC6047744 DOI: 10.1038/nsmb.3494] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [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: 05/02/2017] [Accepted: 09/22/2017] [Indexed: 12/15/2022]
Abstract
Mammalian polymerase theta (Polθ) is a multifunctional enzyme that promotes error-prone DNA repair by alternative nonhomologous end joining (alt-NHEJ). Here we present structure-function analyses that reveal that, in addition to the polymerase domain, Polθ-helicase activity plays a central role during double-strand break (DSB) repair. Our results show that the helicase domain promotes chromosomal translocations by alt-NHEJ in mouse embryonic stem cells and also suppresses CRISPR-Cas9- mediated gene targeting by homologous recombination (HR). In vitro assays demonstrate that Polθ-helicase activity facilitates the removal of RPA from resected DSBs to allow their annealing and subsequent joining by alt-NHEJ. Consistent with an antagonistic role for RPA during alt-NHEJ, inhibition of RPA1 enhances end joining and suppresses recombination. Taken together, our results reveal that the balance between HR and alt-NHEJ is controlled by opposing activities of Polθ and RPA, providing further insight into the regulation of repair-pathway choice in mammalian cells.
Collapse
Affiliation(s)
- Pedro A. Mateos-Gomez
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, USA
- Department of Cell Biology, New York University School of Medicine, New York, USA
| | - Tatiana Kent
- Temple University Lewis Katz School of Medicine, Philadelphia, USA
| | - Sarah K. Deng
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, USA
- Department of Cell Biology, New York University School of Medicine, New York, USA
| | - Shane McDevitt
- Temple University Lewis Katz School of Medicine, Philadelphia, USA
| | | | - Trung M. Hoang
- Temple University Lewis Katz School of Medicine, Philadelphia, USA
| | | | - Agnel Sfeir
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, USA
- Department of Cell Biology, New York University School of Medicine, New York, USA
| |
Collapse
|
5
|
Ahrabi S, Sarkar S, Pfister SX, Pirovano G, Higgins GS, Porter ACG, Humphrey TC. A role for human homologous recombination factors in suppressing microhomology-mediated end joining. Nucleic Acids Res 2016; 44:5743-57. [PMID: 27131361 PMCID: PMC4937322 DOI: 10.1093/nar/gkw326] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [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: 11/14/2015] [Revised: 04/13/2016] [Accepted: 04/14/2016] [Indexed: 12/22/2022] Open
Abstract
DNA double-strand breaks (DSBs) are toxic lesions, which if improperly repaired can result in cell death or genomic instability. DSB repair is usually facilitated by the classical non-homologous end joining (C-NHEJ), or homologous recombination (HR) pathways. However, a mutagenic alternative NHEJ pathway, microhomology-mediated end joining (MMEJ), can also be deployed. While MMEJ is suppressed by C-NHEJ, the relationship between HR and MMEJ is less clear. Here, we describe a role for HR genes in suppressing MMEJ in human cells. By monitoring DSB mis-repair using a sensitive HPRT assay, we found that depletion of HR proteins, including BRCA2, BRCA1 or RPA, resulted in a distinct mutational signature associated with significant increases in break-induced mutation frequencies, deletion lengths and the annealing of short regions of microhomology (2-6 bp) across the break-site. This signature was dependent on CtIP, MRE11, POLQ and PARP, and thus indicative of MMEJ. In contrast to CtIP or MRE11, depletion of BRCA1 resulted in increased partial resection and MMEJ, thus revealing a functional distinction between these early acting HR factors. Together these findings indicate that HR factors suppress mutagenic MMEJ following DSB resection.
Collapse
Affiliation(s)
- Sara Ahrabi
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sovan Sarkar
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sophia X Pfister
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Giacomo Pirovano
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Geoff S Higgins
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Andrew C G Porter
- Gene Targeting Group, Centre for Haematology, Imperial College Faculty of Medicine, London W12 0NN, UK
| | - Timothy C Humphrey
- CRUK MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| |
Collapse
|
6
|
Patrone JD, Pelz NF, Bates BS, Souza-Fagundes EM, Vangamudi B, Camper DV, Kuznetsov AG, Browning CF, Feldkamp MD, Frank AO, Gilston BA, Olejniczak ET, Rossanese OW, Waterson AG, Chazin WJ, Fesik SW. Identification and Optimization of Anthranilic Acid Based Inhibitors of Replication Protein A. ChemMedChem 2016; 11:893-9. [PMID: 26748787 PMCID: PMC4838552 DOI: 10.1002/cmdc.201500479] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 10/14/2015] [Revised: 12/08/2015] [Indexed: 01/19/2023]
Abstract
Replication protein A (RPA) is an essential single-stranded DNA (ssDNA)-binding protein that initiates the DNA damage response pathway through protein-protein interactions (PPIs) mediated by its 70N domain. The identification and use of chemical probes that can specifically disrupt these interactions is important for validating RPA as a cancer target. A high-throughput screen (HTS) to identify new chemical entities was conducted, and 90 hit compounds were identified. From these initial hits, an anthranilic acid based series was optimized by using a structure-guided iterative medicinal chemistry approach to yield a cell-penetrant compound that binds to RPA70N with an affinity of 812 nm. This compound, 2-(3- (N-(3,4-dichlorophenyl)sulfamoyl)-4-methylbenzamido)benzoic acid (20 c), is capable of inhibiting PPIs mediated by this domain.
Collapse
Affiliation(s)
- James D Patrone
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Rollins College, 1000 Holt Avenue, Winter Park, FL, 32789, USA
| | - Nicholas F Pelz
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Brittney S Bates
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | | | | | - Demarco V Camper
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alexey G Kuznetsov
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Carrie F Browning
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Michael D Feldkamp
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Andreas O Frank
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Benjamin A Gilston
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edward T Olejniczak
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Olivia W Rossanese
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alex G Waterson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Stephen W Fesik
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA.
| |
Collapse
|