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Jaiswal AS, Williamson EA, Jaiswal AS, Kong K, Hromas RA. In Vitro Reconstitutive Base Excision Repair (BER) Assay. Methods Mol Biol 2023; 2701:91-112. [PMID: 37574477 DOI: 10.1007/978-1-0716-3373-1_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The mammalian cell genome is continuously exposed to endogenous and exogenous insults that modify its DNA. These modifications can be single-base lesions, bulky DNA adducts, base dimers, base alkylation, cytosine deamination, nitrosation, or other types of base alteration which interfere with DNA replication. Mammalian cells have evolved with a robust defense mechanism to repair these base modifications (damages) to preserve genomic stability. Base excision repair (BER) is the major defense mechanism for cells to remove these oxidative or alkylated single-base modifications. The base excision repair process involves replacement of a single-nucleotide residue by two sub-pathways, the single-nucleotide (SN) and the multi-nucleotide or long-patch (LP) base excision repair pathways. These reactions have been reproduced in vitro using cell free extracts or purified recombinant proteins involved in the base excision repair pathway. In the present chapter, we describe the detailed methodology to reconstitute base excision repair assay systems. These reconstitutive BER assay systems use artificially synthesized and modified DNA. These reconstitutive assay system will be a true representation of biologically occurring damages and their repair.
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Affiliation(s)
- Aruna S Jaiswal
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, USA.
- Division of Hematology and Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX, USA.
| | - Elizabeth A Williamson
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, USA
| | - Arunima S Jaiswal
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, USA
| | - Kimi Kong
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, USA
| | - Robert A Hromas
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, USA
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2
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Chen X, Hu M, Chen Y, Li A, Hua Y, Jiang H, Li H, Lin M. Targeted deep sequencing reveals APC mutations as predictors of overall survival in Chinese colorectal patients receiving adjuvant chemotherapy. Scand J Gastroenterol 2022; 57:465-472. [PMID: 34978498 DOI: 10.1080/00365521.2021.2022189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Objective: Targeted deep sequencing was used to characterize the mutational spectrum of APC in Chinese colorectal tumors in comparison to that in Caucasians from The Cancer Genome Atlas (TCGA) and to investigate whether APC mutations can predict overall survival in CRC patients receiving adjuvant chemotherapy.Methods: A total of 315 Chinese CRC patients including 241 stage II/III patients receiving fluorouracil-based adjuvant chemotherapy were included in this study. Next generation sequencing was carried out to detect somatic mutations on all APC exons. The associations between APC mutations and overall survival were determined by the Cox proportional hazards model.Results:APC was mutated in 221 of 315 colorectal tumors (70.2%). Chinese CRC had a much higher frequency of missense mutations (16.2% vs. 2.4%), but a lower frequency of nonsense (41.0% vs. 54.2%) and frameshift mutations (10.5% vs. 18.4%) than Caucasian CRC. Among stage II/III patients receiving fluorouracil-based adjuvant chemotherapy, APC mutations showed a significant association with worse survival (HR = 1.69; 95% CI, 1.10-2.62; p = .0179). Of the mutation types, frameshift mutations conferred the highest risk of death (HR = 2.88; 95% CI, 1.54-5.37; p =.0009). Among individual mutation sites, Arg232Ter, the most frequent mutation in Chinese CRC, exhibited the strongest negative impact on survival (HR = 2.65; 95% CI, 1.16-6.03; p =.0202).Conclusion:APC overall mutation was an independent predictor for overall survival of stage II/III CRC patients receiving fluorouracil-based chemotherapy.
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Affiliation(s)
- Xin Chen
- Department of General Surgery, Yangpu Hospital Affiliated to Tongji University, Tongji University School of Medicine, Shanghai, China
| | - Mengjun Hu
- Department of Pathology, Zhuji People's Hospital, Shaoxing, China
| | - Ying Chen
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Institute of Gastrointestinal Surgery and Translational Medicine, Tongji University School of Medicine, Shanghai, China
| | - Ajian Li
- Department of General Surgery, Yangpu Hospital Affiliated to Tongji University, Tongji University School of Medicine, Shanghai, China
| | - Yutong Hua
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Institute of Gastrointestinal Surgery and Translational Medicine, Tongji University School of Medicine, Shanghai, China
| | - Huihong Jiang
- Department of General Surgery, Yangpu Hospital Affiliated to Tongji University, Tongji University School of Medicine, Shanghai, China
| | - Huaguang Li
- Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Institute of Gastrointestinal Surgery and Translational Medicine, Tongji University School of Medicine, Shanghai, China
| | - Moubin Lin
- Department of General Surgery, Yangpu Hospital Affiliated to Tongji University, Tongji University School of Medicine, Shanghai, China.,Center for Clinical Research and Translational Medicine, Yangpu Hospital, Tongji University School of Medicine, Shanghai, China.,Institute of Gastrointestinal Surgery and Translational Medicine, Tongji University School of Medicine, Shanghai, China
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3
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Tortora K, Margheri F, Luceri C, Mocali A, Ristori S, Magnelli L, Caderni G, Giovannelli L. Colon fibroblasts from Pirc rats (F344/NTac-Apc am1137 ) exhibit a proliferative and inflammatory phenotype that could support early stages of colon carcinogenesis. Int J Cancer 2022; 150:362-373. [PMID: 34486752 PMCID: PMC9291568 DOI: 10.1002/ijc.33796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/03/2021] [Accepted: 08/16/2021] [Indexed: 12/28/2022]
Abstract
The role of fibroblast APC mutation in carcinogenesis is not clear. Apc+/− colon fibroblasts have been previously characterized: however, little is known about their behavior at very early‐stage of colon carcinogenesis. We cultured colon mucosa fibroblasts (PCF, Apc+/−) of Pirc rats (F344/NTac‐Apcam1137) at an early stage of tumorigenesis, in absence of preneoplastic lesions, and of age‐matched wt (WCF): DNA damage levels, inflammatory phenotype and the expression of known markers of CAFs were analyzed. The latter were also assessed by microarray analysis on colon normal mucosa of Pirc and wt animals. PCF exhibited higher proliferative rates (P < .001) and delayed replicative senescence onset (P < .05) compared to WCF, along with a lower level of oxidative DNA damage (P < .05). Furthermore, a constitutively higher expression of COX‐2 and sensitivity to inflammatory stimuli was found in PCF compared to WCF (P < .05), accompanied by higher invasive capability (P < .05) and presence of cytoplasmic chromatin foci (cytoplasmic chromatin foci, P < .05). However, they neither expressed CAFs markers (α‐SMA, IL‐6) nor responded to CAFs activating stimuli (TGF‐β). Accordingly, CAFs markers and activating stimuli resulted down‐regulated in Pirc normal mucosa compared to wt, whereas DNA damage response and tolerance pathways were overexpressed. These data show for the first time that a proliferative and inflammatory phenotype characterizes Apc+/− colon fibroblasts since very early stages of colon tumorigenesis, and indicate a role of Apc mutation in driving fibroblast phenotypic alterations that could support the establishment of a protumorigenic environment. Early pharmacological targeting of these dysfunctions might impact on tumor prevention in FAP patients.
What's new?
Heterozygous mutations in APC represent the earliest event in sporadic colorectal carcinogenesis onset and cause familial adenomatous polyposis syndrome. However, the role of APC‐mutated fibroblasts remains unclear. Here, Apc+/‐ fibroblasts isolated from apparently‐normal colon tissue of Pirc rats showed proliferative, inflammatory features and resistance to oxidative DNA damage, although they did not show cancer‐associated fibroblast features. These data suggest that, at the very early stages of colon tumourigenesis, Apc‐mutated colon fibroblasts favour the establishment of a pro‐tumourigenic environment for pre‐neoplastic lesion development. Early pharmacological targeting of these dysfunctions might be valuable for tumour prevention in familial adenomatous polyposis patients.
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Affiliation(s)
- Katia Tortora
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Florence, Italy
| | - Francesca Margheri
- Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Cristina Luceri
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Florence, Italy
| | - Alessandra Mocali
- Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Sara Ristori
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Florence, Italy
| | - Lucia Magnelli
- Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Giovanna Caderni
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Florence, Italy
| | - Lisa Giovannelli
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Florence, Italy
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4
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Sethy C, Kundu CN. PARP inhibitor BMN-673 induced apoptosis by trapping PARP-1 and inhibiting base excision repair via modulation of pol-β in chromatin of breast cancer cells. Toxicol Appl Pharmacol 2022; 436:115860. [PMID: 34998856 DOI: 10.1016/j.taap.2021.115860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/31/2021] [Accepted: 12/31/2021] [Indexed: 01/05/2023]
Abstract
PARP inhibitors emerged as clinically effective anti-tumor agents in combination with DNA damaging agents but the toxicity of DNA damaging agents and their off-target effects caused serious problems in cancer therapy. They confer cytotoxicity in cancer cells both by catalytic inhibition and trapping of PARP-1 at the DNA damage site. There is a lack of direct evidence to quantitatively determine the trapped PARP-1 in cellular DNA. Here, we have precisely evaluated the mechanism of PARP trapping mediated anti-cancer action of Quinacrine (QC), BMN-673, and their combination (QC + BMN-673) in breast cancer cells. We introduced a strategy to measure the cellular PARP trapping potentiality of BMN-673 in QC pretreated cells using a fluorescence-based assay system. It was found that QC+ BMN-673 induced apoptosis by triggering DNA damage in breast cancer cells. Treatment with QC + BMN-673 stimulated the expression of PARP-1 in the chromatin compared to that of PARP-2 and PARP-3. QC + BMN-673 treatment also caused a dose-dependent and time-dependent accumulation of PARP-1 and inhibition of PARylation in the chromatin. Upregulation of BER components (pol-β and FEN-1), an unchanged HR and NHEJ pathway proteins, and reduction of luciferase activity of the cells transfected with R-p21-P (LP-BER) were noted in combined drug-treated cells. Interestingly, silencing of pol-β resulted in unchanged PARP-1 trapping and PAR activity in the chromatin with increasing time after QC + BMN-673 treatment without altering APC and FEN-1 expression. Thus, our data suggested that the QC + BMN-673 augmented breast cancer cell death by pol-β mediated repair inhibition primarily through trapping of PARP-1 besides PARP-1 catalytic inhibition.
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Affiliation(s)
- Chinmayee Sethy
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
| | - Chanakya Nath Kundu
- Cancer Biology Division, School of Biotechnology, Kalinga Institute of Industrial Technology, Campus-11, Patia, Bhubaneswar, Odisha 751024, India.
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5
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Tortora K, Vitali F, De Filippo C, Caderni G, Giovannelli L. DNA damage in colon mucosa of Pirc rats, an Apc-driven model of colon tumorigenesis. Toxicol Lett 2020; 324:12-19. [PMID: 32035981 DOI: 10.1016/j.toxlet.2020.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 01/15/2020] [Accepted: 02/02/2020] [Indexed: 02/08/2023]
Abstract
APC mutation is the first event triggering colon carcinogenesis (CRC). The contribution of APC to colon mucosa DNA damage is not well characterized yet. Similarly, the role of genotoxin-producer gut microorganisms is unclear. DNA strand breaks and oxidative damage were measured in Pirc rats, mutated in Apc, with the COMET assay at age 1 (T1) and 11 months (T11), i.e. in absence and presence of colon adenomas. In Pirc colon mucosa a 2-fold increase in the mean level of DNA oxidative damage was found at T11 compared to T1. Moreover, the analysis of DNA damage distribution showed that the proportion of Pirc mucosa cells in the highest DNA damage class was increased compared to wt rats at T1 and T11 months (p < 0.05 and <0.001, respectively). The analysis of colon mucosa-associated microbiota composition showed that this result was not attributable to the presence of genotoxin-producer bacteria B. fragilis nor E. coli. However, Pirc colon mucosa was enriched in Clostridium cluster XI, harmful bacteria in the large intestine, while the wt colon mucosa was enriched in Clostridium cluster IV. This work provides an original way to investigate the interplay between Apc and gut microbiota in affecting DNA stability during CRC.
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Affiliation(s)
- Katia Tortora
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - Francesco Vitali
- Institute of Agricultural Biology and Biotechnology, National Research Council, Via Moruzzi, 1, 56124 Pisa, Italy
| | - Carlotta De Filippo
- Institute of Agricultural Biology and Biotechnology, National Research Council, Via Moruzzi, 1, 56124 Pisa, Italy
| | - Giovanna Caderni
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - Lisa Giovannelli
- NEUROFARBA Department, Pharmacology and Toxicology Section, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
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6
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Jaiswal AS, Williamson EA, Srinivasan G, Kong K, Lomelino CL, McKenna R, Walter C, Sung P, Narayan S, Hromas R. The splicing component ISY1 regulates APE1 in base excision repair. DNA Repair (Amst) 2019; 86:102769. [PMID: 31887540 DOI: 10.1016/j.dnarep.2019.102769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 11/01/2019] [Accepted: 12/09/2019] [Indexed: 11/19/2022]
Abstract
The integrity of cellular genome is continuously challenged by endogenous and exogenous DNA damaging agents. If DNA damage is not removed in a timely fashion the replisome may stall at DNA lesions, causing fork collapse and genetic instability. Base excision DNA repair (BER) is the most important pathway for the removal of oxidized or mono-alkylated DNA. While the main components of the BER pathway are well defined, its regulatory mechanism is not yet understood. We report here that the splicing factor ISY1 enhances apurinic/apyrimidinic endonuclease 1 (APE1) activity, the multifunctional enzyme in BER, by promoting its 5'-3' endonuclease activity. ISY1 expression is induced by oxidative damage, which would provide an immediate up-regulation of APE1 activity in vivo and enhance BER of oxidized bases. We further found that APE1 and ISY1 interact, and ISY1 enhances the ability of APE1 to recognize abasic sites in DNA. Using purified recombinant proteins, we reconstituted BER and demonstrated that ISY1 markedly promoted APE1 activity in both the short- and long-patch BER pathways. Our study identified ISY1 as a regulator of the BER pathway, which would be of physiological relevance where suboptimal levels of APE1 are present. The interaction of ISY1 and APE1 also establishes a connection between DNA damage repair and pre-mRNA splicing.
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Affiliation(s)
- Aruna S Jaiswal
- Division of Hematology and Medical Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229 United States.
| | - Elizabeth A Williamson
- Division of Hematology and Medical Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229 United States
| | - Gayathri Srinivasan
- Division of Hematology and Medical Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229 United States
| | - Kimi Kong
- Division of Hematology and Medical Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229 United States
| | - Carrie L Lomelino
- Department of Biochemistry and Molecular Biology, University of Florida Health, Gainesville, FL 32610 United States
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, University of Florida Health, Gainesville, FL 32610 United States
| | - Christi Walter
- Department of Cell Systems and Anatomy, University of Texas Health Science Center, San Antonio, TX 78229 United States
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT 06520 San Antonio, TX 78229 United States
| | - Satya Narayan
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610 United States
| | - Robert Hromas
- Division of Hematology and Medical Oncology, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229 United States.
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7
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Kathera C, Zhang J, Janardhan A, Sun H, Ali W, Zhou X, He L, Guo Z. Interacting partners of FEN1 and its role in the development of anticancer therapeutics. Oncotarget 2017; 8:27593-27602. [PMID: 28187440 PMCID: PMC5432360 DOI: 10.18632/oncotarget.15176] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 01/24/2017] [Indexed: 11/25/2022] Open
Abstract
Protein-protein interaction (PPI) plays a key role in cellular communication, Protein-protein interaction connected with each other with hubs and nods involved in signaling pathways. These interactions used to develop network based biomarkers for early diagnosis of cancer. FEN1(Flap endonuclease 1) is a central component in cellular metabolism, over expression and decrease of FEN1 levels may cause cancer, these regulation changes of Flap endonuclease 1reported in many cancer cells, to consider this data may needs to develop a network based biomarker. The current review focused on types of PPI, based on nature, detection methods and its role in cancer. Interacting partners of Flap endonuclease 1 role in DNA replication repair and development of anticancer therapeutics based on Protein-protein interaction data.
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Affiliation(s)
- Chandrasekhar Kathera
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Jing Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Avilala Janardhan
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Hongfang Sun
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Wajid Ali
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xiaolong Zhou
- The Laboratory of Animal Genetics, Breeding, and Reproduction, College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, China
| | - Lingfeng He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Zhigang Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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8
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ABT-888 and quinacrine induced apoptosis in metastatic breast cancer stem cells by inhibiting base excision repair via adenomatous polyposis coli. DNA Repair (Amst) 2016; 45:44-55. [DOI: 10.1016/j.dnarep.2016.05.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 05/23/2016] [Accepted: 05/27/2016] [Indexed: 01/21/2023]
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9
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Schell MJ, Yang M, Teer JK, Lo FY, Madan A, Coppola D, Monteiro ANA, Nebozhyn MV, Yue B, Loboda A, Bien-Willner GA, Greenawalt DM, Yeatman TJ. A multigene mutation classification of 468 colorectal cancers reveals a prognostic role for APC. Nat Commun 2016; 7:11743. [PMID: 27302369 PMCID: PMC4912618 DOI: 10.1038/ncomms11743] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 04/25/2016] [Indexed: 02/07/2023] Open
Abstract
Colorectal cancer (CRC) is a highly heterogeneous disease, for which prognosis has been relegated to clinicopathologic staging for decades. There is a need to stratify subpopulations of CRC on a molecular basis to better predict outcome and assign therapies. Here we report targeted exome-sequencing of 1,321 cancer-related genes on 468 tumour specimens, which identified a subset of 17 genes that best classify CRC, with APC playing a central role in predicting overall survival. APC may assume 0, 1 or 2 truncating mutations, each with a striking differential impact on survival. Tumours lacking any APC mutation carry a worse prognosis than single APC mutation tumours; however, two APC mutation tumours with mutant KRAS and TP53 confer the poorest survival among all the subgroups examined. Our study demonstrates a prognostic role for APC and suggests that sequencing of APC may have clinical utility in the routine staging and potential therapeutic assignment for CRC.
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Affiliation(s)
- Michael J Schell
- Department of Biostatistics and Bioinformatics, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida 33612, USA
| | - Mingli Yang
- Gibbs Cancer Center and Research Institute, 380 Serpentine Drive, Spartanburg, South Carolina 29303, USA
| | - Jamie K Teer
- Department of Biostatistics and Bioinformatics, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida 33612, USA
| | - Fang Yin Lo
- Genomic Services, LabCorp Clinical Trials, 401 Terry Avenue North, Suite 200, Seattle, Washington 98109, USA
| | - Anup Madan
- Genomic Services, LabCorp Clinical Trials, 401 Terry Avenue North, Suite 200, Seattle, Washington 98109, USA
| | - Domenico Coppola
- Department of Anatomic Pathology, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida 33612, USA
| | - Alvaro N A Monteiro
- Department of Epidemiology, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida 33612, USA
| | - Michael V Nebozhyn
- Genetics and Pharmacogenomics, Merck, Sharp and Dohme, PO Box 4, 770 Sumneytown Pike, Building 53, West Point, Pennsylvania 19486, USA
| | - Binglin Yue
- Department of Biostatistics and Bioinformatics, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida 33612, USA
| | - Andrey Loboda
- Genetics and Pharmacogenomics, Merck, Sharp and Dohme, PO Box 4, 770 Sumneytown Pike, Building 53, West Point, Pennsylvania 19486, USA
| | | | - Danielle M Greenawalt
- Genetics and Pharmacogenomics, Merck, Sharp and Dohme, PO Box 4, 770 Sumneytown Pike, Building 53, West Point, Pennsylvania 19486, USA
| | - Timothy J Yeatman
- Gibbs Cancer Center and Research Institute, 380 Serpentine Drive, Spartanburg, South Carolina 29303, USA
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10
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Interaction between APC and Fen1 during breast carcinogenesis. DNA Repair (Amst) 2016; 41:54-62. [PMID: 27088617 DOI: 10.1016/j.dnarep.2016.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 04/06/2016] [Indexed: 02/07/2023]
Abstract
Aberrant DNA base excision repair (BER) contributes to malignant transformation. However, inter-individual variations in DNA repair capacity plays a key role in modifying breast cancer risk. We review here emerging evidence that two proteins involved in BER - adenomatous polyposis coli (APC) and flap endonuclease 1 (Fen1) - promote the development of breast cancer through novel mechanisms. APC and Fen1 expression and interaction is increased in breast tumors versus normal cells, APC interacts with and blocks Fen1 activity in Pol-β-directed LP-BER, and abrogation of LP-BER is linked with cigarette smoke condensate-induced transformation of normal breast epithelial cells. Carcinogens increase expression of APC and Fen1 in spontaneously immortalized human breast epithelial cells, human colon cancer cells, and mouse embryonic fibroblasts. Since APC and Fen1 are tumor suppressors, an increase in their levels could protect against carcinogenesis; however, this does not seem to be the case. Elevated Fen1 levels in breast and lung cancer cells may reflect the enhanced proliferation of cancer cells or increased DNA damage in cancer cells compared to normal cells. Inactivation of the tumor suppressor functions of APC and Fen1 is due to their interaction, which may act as a susceptibility factor for breast cancer. The increased interaction of APC and Fen1 may occur due to polypmorphic and/or mutational variation in these genes. Screening of APC and Fen1 polymorphic and/or mutational variations and APC/Fen1 interaction may permit assessment of individual DNA repair capability and the risk for breast cancer development. Such individuals might lower their breast cancer risk by reducing exposure to carcinogens. Stratifying individuals according to susceptibility would greatly assist epidemiologic studies of the impact of suspected environmental carcinogens. Additionally, a mechanistic understanding of the interaction of APC and Fen1 may provide the basis for developing new and effective targeted chemopreventive and chemotherapeutic agents.
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11
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Das D, Preet R, Mohapatra P, Satapathy SR, Siddharth S, Tamir T, Jain V, Bharatam PV, Wyatt MD, Kundu CN. 5-Fluorouracil mediated anti-cancer activity in colon cancer cells is through the induction of Adenomatous Polyposis Coli: Implication of the long-patch base excision repair pathway. DNA Repair (Amst) 2015; 24:15-25. [PMID: 25460919 DOI: 10.1016/j.dnarep.2014.10.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 12/18/2022]
Abstract
Colorectal cancer (CRC) patients with APC mutations do not benefit from 5-FU therapy. It was reported that APC physically interacts with POLβ and FEN1, thus blocking LP-BER via APC's DNA repair inhibitory (DRI) domain in vitro. The aim of this study was to elucidate how APC status affects BER and the response of CRC to 5-FU. HCT-116, HT-29, and LOVO cells varying in APC status were treated with 5-FU to evaluate expression, repair, and survival responses. HCT-116 expresses wild-type APC; HT-29 expresses an APC mutant that contains DRI domain; LOVO expresses an APC mutant lacking DRI domain. 5-FU increased the expression of APC and decreased the expression of FEN1 in HCT-116 and HT-29 cells, which were sensitized to 5-FU when compared to LOVO cells. Knockdown of APC in HCT-116 rendered cells resistant to 5-FU, and FEN1 levels remained unchanged. Re-expression of full-length APC in LOVO cells caused sensitivity to 5-FU, and decreased expression of FEN1. These knockdown and addback studies confirmed that the DRI domain is necessary for the APC-mediated reduction in LP-BER and 5-FU. Modelling studies showed that 5-FU can interact with the DRI domain of APC via hydrogen bonding and hydrophobic interactions. 5-FU resistance in CRC occurs with mutations in APC that disrupt or eliminate the DRI domain's interaction with LP-BER. Understanding the type of APC mutation should better predict 5-FU resistance in CRC than simply characterizing APC status as wild-type or mutant.
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Affiliation(s)
- Dipon Das
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India
| | - Ranjan Preet
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India
| | - Purusottam Mohapatra
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India
| | - Shakti Ranjan Satapathy
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India
| | - Sumit Siddharth
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India
| | - Tigist Tamir
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Vaibhav Jain
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Mohali, Punjab 160062, India
| | - Prasad V Bharatam
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Mohali, Punjab 160062, India
| | - Michael D Wyatt
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Chanakya Nath Kundu
- KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024, India.
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12
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White AJ, Chen J, McCullough LE, Xu X, Cho YH, Teitelbaum SL, Neugut AI, Terry MB, Hibshoosh H, Santella RM, Gammon MD. Polycyclic aromatic hydrocarbon (PAH)-DNA adducts and breast cancer: modification by gene promoter methylation in a population-based study. Cancer Causes Control 2015; 26:1791-802. [PMID: 26407953 DOI: 10.1007/s10552-015-0672-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 09/16/2015] [Indexed: 12/19/2022]
Abstract
PURPOSE Polycyclic aromatic hydrocarbon (PAH)-DNA adducts have been associated with breast cancer incidence. Aberrant changes in DNA methylation may be an early event in carcinogenesis. However, possible relations between PAH-DNA adducts, methylation, and breast cancer are unknown. The objectives of this study were to (1) assess associations between PAH-DNA adducts, and breast cancer, stratified by DNA methylation markers and (2) examine interactions between adducts and DNA methylation in association with breast cancer and tumor subtype. METHODS In a population-based case-control study, promoter methylation of 13 breast cancer-related genes was measured in tumor tissue (n = 765-851 cases). Blood DNA from breast cancer cases (n = 873) and controls (n = 941) was used to assess PAH-DNA adducts and global methylation. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI); and the ratio of the OR (ROR) was used to assess heterogeneity. RESULTS Women with detectable PAH-DNA adducts and methylated RARβ (ROR 2.69, 95% CI 1.02-7.12; p for interaction = 0.03) or APC (ROR 1.76, 95% CI 0.87-3.58; p for interaction = 0.09) genes were more likely to have hormone receptor-positive tumors than other subtypes. Interactions with other methylation markers were not apparent (p ≥ 0.10). The association between adducts and breast cancer did not vary by methylation status of the tumor nor did adducts associate with global methylation in the controls. CONCLUSIONS Gene-specific methylation of RARβ, and perhaps APC, may interact with PAH-DNA adducts to increase risk of hormone receptor-positive breast cancer. There was little evidence that adducts were associated with or interacted with other methylation markers of interest.
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Affiliation(s)
- Alexandra J White
- Department of Epidemiology, University of North Carolina, CB#7435, McGavran-Greenberg Hall, Chapel Hill, NC, 27599-7435, USA.
| | - Jia Chen
- Departments of Preventive Medicine, Ichan School of Medicine at Mt. Sinai, New York, NY, USA.,Departments of Oncological Science, Ichan School of Medicine at Mt. Sinai, New York, NY, USA.,Departments of Pediatrics, Ichan School of Medicine at Mt. Sinai, New York, NY, USA
| | - Lauren E McCullough
- Department of Epidemiology, University of North Carolina, CB#7435, McGavran-Greenberg Hall, Chapel Hill, NC, 27599-7435, USA
| | - Xinran Xu
- Research Center for Translational Medicine, Shanghai East Hospital of Tongji University School of Medicine, Shanghai, China
| | - Yoon Hee Cho
- Department of Environmental Health Sciences, Columbia University, New York, NY, USA
| | - Susan L Teitelbaum
- Departments of Preventive Medicine, Ichan School of Medicine at Mt. Sinai, New York, NY, USA
| | - Alfred I Neugut
- Department of Epidemiology, Columbia University, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA
| | - Mary Beth Terry
- Department of Epidemiology, Columbia University, New York, NY, USA
| | | | - Regina M Santella
- Department of Environmental Health Sciences, Columbia University, New York, NY, USA
| | - Marilie D Gammon
- Department of Epidemiology, University of North Carolina, CB#7435, McGavran-Greenberg Hall, Chapel Hill, NC, 27599-7435, USA
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13
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Narayan S, Sharma R. Molecular mechanism of adenomatous polyposis coli-induced blockade of base excision repair pathway in colorectal carcinogenesis. Life Sci 2015; 139:145-52. [PMID: 26334567 DOI: 10.1016/j.lfs.2015.08.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/31/2015] [Accepted: 08/23/2015] [Indexed: 02/07/2023]
Abstract
Colorectal cancer (CRC) is the third leading cause of death in both men and women in North America. Despite chemotherapeutic efforts, CRC is associated with a high degree of morbidity and mortality. Thus, to develop effective treatment strategies for CRC, one needs knowledge of the pathogenesis of cancer development and cancer resistance. It is suggested that colonic tumors or cell lines harbor truncated adenomatous polyposis coli (APC) without DNA repair inhibitory (DRI)-domain. It is also thought that the product of the APC gene can modulate base excision repair (BER) pathway through an interaction with DNA polymerase β (Pol-β) and flap endonuclease 1 (Fen-1) to mediate CRC cell apoptosis. The proposed therapy with temozolomide (TMZ) exploits this particular pathway; however, a high percentage of colorectal tumors continue to develop resistance to chemotherapy due to mismatch repair (MMR)-deficiency. In the present communication, we have comprehensively reviewed a critical issue that has not been addressed previously: a novel mechanism by which APC-induced blockage of single nucleotide (SN)- and long-patch (LP)-BER play role in DNA-alkylation damage-induced colorectal carcinogenesis.
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Affiliation(s)
- Satya Narayan
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610 United States.
| | - Ritika Sharma
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610 United States
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14
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Targeting the DNA replication checkpoint by pharmacologic inhibition of Chk1 kinase: a strategy to sensitize APC mutant colon cancer cells to 5-fluorouracil chemotherapy. Oncotarget 2015; 5:9889-900. [PMID: 25301724 PMCID: PMC4259445 DOI: 10.18632/oncotarget.2475] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
5-fluorouracil (5-FU) is the first line component used in colorectal cancer (CRC) therapy however even in combination with other chemotherapeutic drugs recurrence is common. Mutations of the adenomatous polyposis coli (APC) gene are considered as the initiating step of transformation in familial and sporadic CRCs. We have previously shown that APC regulates the cellular response to DNA replication stress and recently hypothesized that APC mutations might therefore influence 5-FU resistance. To test this, we compared CRC cell lines and show that those expressing truncated APC exhibit a limited response to 5-FU and arrest in G1/S-phase without undergoing lethal damage, unlike cells expressing wild-type APC. In SW480 APC-mutant CRC cells, 5-FU-dependent apoptosis was restored after transient expression of full length APC, indicating a direct link between APC and drug response. Furthermore, we could increase sensitivity of APC truncated cells to 5-FU by inactivating the Chk1 kinase using drug treatment or siRNA-mediated knockdown. Our findings identify mutant APC as a potential tumor biomarker of resistance to 5-FU, and importantly we show that APC-mutant CRC cells can be made more sensitive to 5-FU by use of Chk1 inhibitors.
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15
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Maizels Y, Gerlitz G. Shaping of interphase chromosomes by the microtubule network. FEBS J 2015; 282:3500-24. [PMID: 26040675 DOI: 10.1111/febs.13334] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 05/11/2015] [Accepted: 06/01/2015] [Indexed: 12/31/2022]
Abstract
It is well established that microtubule dynamics play a major role in chromosome condensation and localization during mitosis. During interphase, however, it is assumed that the metazoan nuclear envelope presents a physical barrier, which inhibits interaction between the microtubules located in the cytoplasm and the chromatin fibers located in the nucleus. In recent years, it has become apparent that microtubule dynamics alter chromatin structure and function during interphase as well. Microtubule motor proteins transport several transcription factors and exogenous DNA (such as plasmid DNA) from the cytoplasm to the nucleus. Various soluble microtubule components are able to translocate into the nucleus, where they bind various chromatin elements leading to transcriptional alterations. In addition, microtubules may apply force on the nuclear envelope, which is transmitted into the nucleus, leading to changes in chromatin structure. Thus, microtubule dynamics during interphase may affect chromatin spatial organization, as well as transcription, replication and repair.
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Affiliation(s)
- Yael Maizels
- Department of Molecular Biology, Faculty of Natural Sciences, Ariel University, Israel
| | - Gabi Gerlitz
- Department of Molecular Biology, Faculty of Natural Sciences, Ariel University, Israel
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16
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VanKlompenberg MK, Bedalov CO, Soto KF, Prosperi JR. APC selectively mediates response to chemotherapeutic agents in breast cancer. BMC Cancer 2015; 15:457. [PMID: 26049416 PMCID: PMC4458029 DOI: 10.1186/s12885-015-1456-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 05/20/2015] [Indexed: 02/25/2023] Open
Abstract
Background The Adenomatous Polyposis Coli (APC) tumor suppressor is mutated or hypermethylated in up to 70 % of sporadic breast cancers depending on subtype; however, the effects of APC mutation on tumorigenic properties remain unexplored. Using the ApcMin/+ mouse crossed to the Polyoma middle T antigen (PyMT) transgenic model, we identified enhanced breast tumorigenesis and alterations in genes critical in therapeutic resistance independent of Wnt/β-catenin signaling. Apc mutation changed the tumor histopathology from solid to squamous adenocarcinomas, resembling the highly aggressive human metaplastic breast cancer. Mechanistic studies in tumor-derived cell lines demonstrated that focal adhesion kinase (FAK)/Src/JNK signaling regulated the enhanced proliferation downstream of Apc mutation. Despite this mechanistic information, the role of APC in mediating breast cancer chemotherapeutic resistance is currently unknown. Methods We have examined the effect of Apc loss in MMTV-PyMT mouse breast cancer cells on gene expression changes of ATP-binding cassette transporters and immunofluorescence to determine proliferative and apoptotic response of cells to cisplatin, doxorubicin and paclitaxel. Furthermore we determined the added effect of Src or JNK inhibition by PP2 and SP600125, respectively, on chemotherapeutic response. We also used the Aldefluor assay to measure the population of tumor initiating cells. Lastly, we measured the apoptotic and proliferative response to APC knockdown in MDA-MB-157 human breast cancer cells after chemotherapeutic treatment. Results Cells obtained from MMTV-PyMT;ApcMin/+ tumors express increased MDR1 (multidrug resistance protein 1), which is augmented by treatment with paclitaxel or doxorubicin. Furthermore MMTV-PyMT;ApcMin/+ cells are more resistant to cisplatin and doxorubicin-induced apoptosis, and show a larger population of ALDH positive cells. In the human metaplastic breast cancer cell line MDA-MB-157, APC knockdown led to paclitaxel and cisplatin resistance. Conclusions APC loss-of-function significantly increases resistance to cisplatin-mediated apoptosis in both MDA-MB-157 and the PyMT derived cells. We also demonstrated that cisplatin in combination with PP2 or SP600125 could be clinically beneficial, as inhibition of Src or JNK in an APC-mutant breast cancer patient may alleviate the resistance induced by mutant APC. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1456-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Monica K VanKlompenberg
- Harper Cancer Research Institute, A134 Harper Hall, 1234 Notre Dame Ave., South Bend, IN, 46617, USA.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine - South Bend, South Bend, IN, USA
| | - Claire O Bedalov
- Harper Cancer Research Institute, A134 Harper Hall, 1234 Notre Dame Ave., South Bend, IN, 46617, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Katia Fernandez Soto
- Harper Cancer Research Institute, A134 Harper Hall, 1234 Notre Dame Ave., South Bend, IN, 46617, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Jenifer R Prosperi
- Harper Cancer Research Institute, A134 Harper Hall, 1234 Notre Dame Ave., South Bend, IN, 46617, USA. .,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine - South Bend, South Bend, IN, USA. .,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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17
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Jaiswal AS, Panda H, Law BK, Sharma J, Jani J, Hromas R, Narayan S. NSC666715 and Its Analogs Inhibit Strand-Displacement Activity of DNA Polymerase β and Potentiate Temozolomide-Induced DNA Damage, Senescence and Apoptosis in Colorectal Cancer Cells. PLoS One 2015; 10:e0123808. [PMID: 25933036 PMCID: PMC4416822 DOI: 10.1371/journal.pone.0123808] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 03/07/2015] [Indexed: 01/29/2023] Open
Abstract
Recently approved chemotherapeutic agents to treat colorectal cancer (CRC) have made some impact; however, there is an urgent need for newer targeted agents and strategies to circumvent CRC growth and metastasis. CRC frequently exhibits natural resistance to chemotherapy and those who do respond initially later acquire drug resistance. A mechanism to potentially sensitize CRC cells is by blocking the DNA polymerase β (Pol-β) activity. Temozolomide (TMZ), an alkylating agent, and other DNA-interacting agents exert DNA damage primarily repaired by a Pol-β-directed base excision repair (BER) pathway. In previous studies, we used structure-based molecular docking of Pol-β and identified a potent small molecule inhibitor (NSC666715). In the present study, we have determined the mechanism by which NSC666715 and its analogs block Fen1-induced strand-displacement activity of Pol-β-directed LP-BER, cause apurinic/apyrimidinic (AP) site accumulation and induce S-phase cell cycle arrest. Induction of S-phase cell cycle arrest leads to senescence and apoptosis of CRC cells through the p53/p21 pathway. Our initial findings also show a 10-fold reduction of the IC50 of TMZ when combined with NSC666715. These results provide a guide for the development of a target-defined strategy for CRC chemotherapy that will be based on the mechanisms of action of NSC666715 and TMZ. This combination strategy can be used as a framework to further reduce the TMZ dosages and resistance in CRC patients.
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Affiliation(s)
- Aruna S. Jaiswal
- Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Harekrushna Panda
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Brian K. Law
- Department of Pharmacology and Experimental Therapeutics, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Jay Sharma
- Celprogen Inc., Torrance, California, 90503, United States of America
| | - Jitesh Jani
- Celprogen Inc., Torrance, California, 90503, United States of America
| | - Robert Hromas
- Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Satya Narayan
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, Florida, 32610, United States of America
- * E-mail:
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18
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ZHANG YINING, XIAO QINGHUAN, ZHANG HUIJING, SUN XUREN, GE HUIJUAN, LIU XIAOMING, GUAN LIN, SUN MINGJUN. Adenomatous polyposis coli determines sensitivity to the EGFR tyrosine kinase inhibitor gefitinib in colorectal cancer cells. Oncol Rep 2014; 31:1811-7. [DOI: 10.3892/or.2014.3041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/05/2014] [Indexed: 11/05/2022] Open
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19
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Das D, Preet R, Mohapatra P, Satapathy SR, Kundu CN. 1,3-Bis(2-chloroethyl)-1-nitrosourea enhances the inhibitory effect of Resveratrol on 5-fluorouracil sensitive/resistant colon cancer cells. World J Gastroenterol 2013; 19:7374-7388. [PMID: 24259968 PMCID: PMC3831219 DOI: 10.3748/wjg.v19.i42.7374] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/22/2013] [Accepted: 06/06/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the mechanism of 5-fluorouracil (5-FU) resistance in colon cancer cells and to develop strategies for overcoming such resistance by combination treatment.
METHODS: We established and characterized a 5-FU resistance (5-FU-R) cell line derived from continuous exposure (25 μmol/L) to 5-FU for 20 wk in 5-FU sensitive HCT-116 cells. The proliferation and expression of different representative apoptosis and anti-apoptosis markers in 5-FU sensitive and 5-FU resistance cells were measured by the MTT assay and by Western blotting, respectively, after treatment with Resveratrol (Res) and/or 1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU). Apoptosis and cell cycle arrest was measured by 4',6'-diamidino-2-phenylindole hydrochloride staining and fluorescence-activated cell sorting analysis, respectively. The extent of DNA damage was measured by the Comet assay. We measured the visible changes in the DNA damage/repair cascade by Western blotting.
RESULTS: The widely used chemotherapeutic agents BCNU and Res decreased the growth of 5-FU sensitive HCT-116 cells in a dose dependent manner. Combined application of BCNU and Res caused more apoptosis in 5-FU sensitive cells in comparison to individual treatment. In addition, the combined application of BCNU and Res caused a significant decrease of major DNA base excision repair components in 5-FU sensitive cells. We established a 5-FU resistance cell line (5-FU-R) from 5-FU-sensitive HCT-116 (mismatch repair deficient) cells that was not resistant to other chemotherapeutic agents (e.g., BCNU, Res) except 5-FU. The 5-FU resistance of 5-FU-R cells was assessed by exposure to increasing concentrations of 5-FU followed by the MTT assay. There was no significant cell death noted in 5-FU-R cells in comparison to 5-FU sensitive cells after 5-FU treatment. This resistant cell line overexpressed anti-apoptotic [e.g., AKT, nuclear factor κB, FLICE-like inhibitory protein), DNA repair (e.g., DNA polymerase beta (POL-β), DNA polymerase eta (POLH), protein Flap endonuclease 1 (FEN1), DNA damage-binding protein 2 (DDB2)] and 5-FU-resistance proteins (thymidylate synthase) but under expressed pro-apoptotic proteins (e.g., DAB2, CK1) in comparison to the parental cells. Increased genotoxicity and apoptosis were observed in resistant cells after combined application of BCNU and Res in comparison to untreated or parental cells. BCNU increased the sensitivity to Res of 5-FU resistant cells compared with parental cells. Fifty percent cell death were noted in parental cells when 18 μmol/L of Res was associated with fixed concentration (20 μmol/L) of BCNU, but a much lower concentration of Res (8 μmol/L) was needed to achieve the same effect in 5-FU resistant cells. Interestingly, increased levels of adenomatous polyposis coli and decreased levels POL-β, POLH, FEN1 and DDB2 were noted after the same combined treatment in resistant cells.
CONCLUSION: BCNU combined with Res exerts a synergistic effect that may prove useful for the treatment of colon cancer and to overcome drug resistance.
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20
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Jaiswal AS, Panda H, Pampo CA, Siemann DW, Gairola CG, Hromas R, Narayan S. Adenomatous polyposis coli-mediated accumulation of abasic DNA lesions lead to cigarette smoke condensate-induced neoplastic transformation of normal breast epithelial cells. Neoplasia 2013; 15:454-60. [PMID: 23555190 PMCID: PMC3612917 DOI: 10.1593/neo.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 02/06/2013] [Accepted: 02/08/2013] [Indexed: 11/18/2022]
Abstract
Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5'-flap endonuclease 1 and interferes in BER. Previously, we have also reported that cigarette smoke condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model.
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Affiliation(s)
- Aruna S Jaiswal
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL
- Department of Medicine, University of Florida, Gainesville, FL
| | - Harekrushna Panda
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL
| | - Christine A Pampo
- Department of Radiation Oncology, University of Florida, Gainesville, FL
| | - Dietmar W Siemann
- Department of Radiation Oncology, University of Florida, Gainesville, FL
| | - C Gary Gairola
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY
| | - Robert Hromas
- Department of Medicine, University of Florida, Gainesville, FL
| | - Satya Narayan
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL
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21
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Adenomatous polyposis coli interacts with flap endonuclease 1 to block its nuclear entry and function. Neoplasia 2012; 14:495-508. [PMID: 22787431 DOI: 10.1593/neo.12680] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 05/04/2012] [Accepted: 05/07/2012] [Indexed: 11/18/2022] Open
Abstract
In previous studies, we found that adenomatous polyposis coli (APC) blocks the base excision repair (BER) pathway by interacting with 5'-flap endonuclease 1 (Fen1). In this study, we identify the molecular features that contribute to the formation and/or stabilization of the APC/Fen1 complex that determines the extent of BER inhibition, and the subsequent accumulation of DNA damage creates mutagenic lesions leading to transformation susceptibility. We show here that APC binds to the nuclear localization sequence of Fen1 (Lys(365)Lys(366)Lys(367)), which prevents entry of Fen1 into the nucleus and participation in Pol-β-directed long-patch BER. We also show that levels of the APC/Fen1 complex are higher in breast tumors than in the surrounding normal tissues. These studies demonstrate a novel role for APC in the suppression of Fen1 activity in the BER pathway and a new biomarker profile to be explored to identify individuals who may be susceptible to the development of mammary and other tumors.
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22
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Preet R, Mohapatra P, Das D, Satapathy SR, Choudhuri T, Wyatt MD, Kundu CN. Lycopene synergistically enhances quinacrine action to inhibit Wnt-TCF signaling in breast cancer cells through APC. Carcinogenesis 2012; 34:277-86. [PMID: 23129580 DOI: 10.1093/carcin/bgs351] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We previously reported that quinacrine (QC) has anticancer activity against breast cancer cells. Here, we examine the mechanism of action of QC and its ability to inhibit Wnt-TCF signaling in two independent breast cancer cell lines. QC altered Wnt-TCF signaling components by increasing the levels of adenomatous polyposis coli (APC), DAB2, GSK-3β and axin and decreasing the levels of β-catenin, p-GSK3β (ser 9) and CK1. QC also reduced the activity of the Wnt transcription factor TCF/LEF and its downstream targets cyclin D1 and c-MYC. Using a luciferase-based Wnt-TCF transcription factor assay, it was shown that APC levels were inversely associated with TCF/LEF activity. Induction of apoptosis and DNA damage was observed after treatment with QC, which was associated with increased expression of APC. The effects induced by QC depend on APC because the inhibition of Wnt-TCF signaling by QC is lost in APC-knockdown cells, and consequently, the extent of apoptosis and DNA damage caused by QC is reduced compared with parental cells. Because we previously showed that QC inhibits topoisomerase, we examined the effect of another topoisomerase inhibitor, etoposide, on Wnt signaling. Interestingly, etoposide treatment also reduced TCF/LEF activity, β-catenin and cyclin D1 levels commensurate with induction of DNA damage and apoptosis. Lycopene, a plant-derived antioxidant, synergistically increased QC activity and inhibited Wnt-TCF signaling in cancer cells without affecting the MCF-10A normal breast cell line. Collectively, the data suggest that QC-mediated Wnt-TCF signal inhibition depends on APC and that the addition of lycopene synergistically increases QC anticancer activity.
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Affiliation(s)
- Ranjan Preet
- Cancer Biology Laboratory, Department of KIIT School of Biotechnology, Campus-11, KIIT University, Patia, Bhubaneswar, Orissa 751024, India
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23
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Prasad R, Williams JG, Hou EW, Wilson SH. Pol β associated complex and base excision repair factors in mouse fibroblasts. Nucleic Acids Res 2012; 40:11571-82. [PMID: 23042675 PMCID: PMC3526277 DOI: 10.1093/nar/gks898] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During mammalian base excision repair (BER) of lesion-containing DNA, it is proposed that toxic strand-break intermediates generated throughout the pathway are sequestered and passed from one step to the next until repair is complete. This stepwise process is termed substrate channeling. A working model evaluated here is that a complex of BER factors may facilitate the BER process. FLAG-tagged DNA polymerase (pol) β was expressed in mouse fibroblasts carrying a deletion in the endogenous pol β gene, and the cell extract was subjected to an ‘affinity-capture’ procedure using anti-FLAG antibody. The pol β affinity-capture fraction (ACF) was found to contain several BER factors including polymerase-1, X-ray cross-complementing factor1-DNA ligase III and enzymes involved in processing 3′-blocked ends of BER intermediates, e.g. polynucleotide kinase and tyrosyl-DNA phosphodiesterase 1. In contrast, DNA glycosylases, apurinic/aprymidinic endonuclease 1 and flap endonuclease 1 and several other factors involved in BER were not present. Some of the BER factors in the pol β ACF were in a multi-protein complex as observed by sucrose gradient centrifugation. The pol β ACF was capable of substrate channeling for steps in vitro BER and was proficient in in vitro repair of substrates mimicking a 3′-blocked topoisomerase I covalent intermediate or an oxidative stress-induced 3′-blocked intermediate.
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Affiliation(s)
- Rajendra Prasad
- Laboratory of Structural Biology, NIEHS, National Institutes of Health, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
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Abstract
This review is focusing on a critical mediator of embryonic and postnatal development with multiple implications in inflammation, neoplasia, and other pathological situations in brain and peripheral tissues. These morphogenetic guidance and dependence processes are involved in several malignancies targeting the epithelial and immune systems including the progression of human colorectal cancers. We consider the most important findings and their impact on basic, translational, and clinical cancer research. Expected information can bring new cues for innovative, efficient, and safe strategies of personalized medicine based on molecular markers, protagonists, signaling networks, and effectors inherent to the Netrin axis in pathophysiological states.
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25
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Lui C, Mills K, Brocardo MG, Sharma M, Henderson BR. APC as a mobile scaffold: regulation and function at the nucleus, centrosomes, and mitochondria. IUBMB Life 2011; 64:209-14. [PMID: 22162224 DOI: 10.1002/iub.599] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/02/2011] [Indexed: 12/13/2022]
Abstract
Genetic mutations of adenomatous polyposis coli (APC) predispose to high risk of human colon cancer. APC is a large tumor suppressor protein and truncating mutations disrupt its normal roles in regulating cell migration, DNA replication/repair, mitosis, apoptosis, and turnover of oncogenic β-catenin. APC is targeted to multiple subcellular sites, and here we discuss recent evidence implicating novel protein interactions and functions of APC in the nucleus and at centrosomes and mitochondria. The ability of APC to shuttle between these and other cell locations is hypothesized to be integral to its cellular function.
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Affiliation(s)
- Christina Lui
- Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute at Westmead Hospital, New South Wales, Australia
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Brocardo MG, Borowiec JA, Henderson BR. Adenomatous polyposis coli protein regulates the cellular response to DNA replication stress. Int J Biochem Cell Biol 2011; 43:1354-64. [PMID: 21664290 DOI: 10.1016/j.biocel.2011.05.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 05/12/2011] [Accepted: 05/24/2011] [Indexed: 10/18/2022]
Abstract
The adenomatous polyposis coli (APC) tumor suppressor traffics between nucleus and cytoplasm to perform distinct functions. Here we identify a specific role for APC in the DNA replication stress response. The silencing of APC caused an accumulation of asynchronous cells in early S phase and delayed S phase progression in cells released from hydroxyurea-mediated replication arrest. Immunoprecipitation assays revealed a selective binding of APC to replication protein A 32kDa subunit (RPA32), and the APC-RPA32 complex increased at chromatin after hydroxyurea treatment. Interestingly, APC knock-down prevented accumulation at chromatin of the stress-induced S33- and S29-phosphorylated forms of RPA32, and reduced the expression of ATR-phosphorylated forms of S317-phospho-Chk1 and γ-H2AX. Using RPA32-inducible cells we showed that reconstitution of RPA32 diminished the S-phase delay caused by loss of APC. In contrast to full-length APC, the truncated APC mutant protein expressed in SW480 colon cancer cells was impaired in its binding and regulation of RPA32, and failed to regulate cell cycle after replication stress. We propose that APC associates with RPA at stalled DNA replication forks and promotes the ATR-dependent phosphorylation of RPA32, Chk1 and γ-H2AX in response to DNA replication stress, thereby influencing the rate of re-entry into the cell cycle.
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Affiliation(s)
- Mariana G Brocardo
- Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute at Westmead Hospital, Westmead, New South Wales 2145, Australia.
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Jaiswal AS, Narayan S. Assembly of the base excision repair complex on abasic DNA and role of adenomatous polyposis coli on its functional activity. Biochemistry 2011; 50:1901-9. [PMID: 21261287 DOI: 10.1021/bi102000q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The assembly and stability of base excision repair (BER) proteins in vivo with abasic DNA and the role of adenomatous polyposis coli (APC) protein in this process are currently unclear. We have studied the assembly of a multiprotein BER complex onto abasic DNA (F-DNA) and characterized the physical and functional activity of the associated proteins. We found that the BER complex contained all the essential components of the long-patch BER system, such as APE1, Pol-β, Fen1, and DNA ligase I. Interestingly, wild-type APC was also present in the BER complex. Kinetics of the assembly of BER proteins onto the F-DNA were rapid and appeared in sequential order depending upon their requirement in the repair process. The presence of wild-type APC in the BER complex caused a decrease in the level of assembly of BER proteins and negatively affected long-patch BER. These results suggest that major BER proteins in the complex are assembled onto F-DNA and are competent in performing DNA repair. Wild-type APC in the BER complex reduces the repair activity, probably because of interaction with multiple components of the system.
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Affiliation(s)
- Aruna S Jaiswal
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, Florida 32610, United States.
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Jaiswal AS, Banerjee S, Aneja R, Sarkar FH, Ostrov DA, Narayan S. DNA polymerase β as a novel target for chemotherapeutic intervention of colorectal cancer. PLoS One 2011; 6:e16691. [PMID: 21311763 PMCID: PMC3032781 DOI: 10.1371/journal.pone.0016691] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 01/03/2011] [Indexed: 01/22/2023] Open
Abstract
Chemoprevention presents a major strategy for the medical management of colorectal cancer. Most drugs used for colorectal cancer therapy induce DNA-alkylation damage, which is primarily repaired by the base excision repair (BER) pathway. Thus, blockade of BER pathway is an attractive option to inhibit the spread of colorectal cancer. Using an in silico approach, we performed a structure-based screen by docking small-molecules onto DNA polymerase β (Pol-β) and identified a potent anti-Pol-β compound, NSC-124854. Our goal was to examine whether NSC-124854 could enhance the therapeutic efficacy of DNA-alkylating agent, Temozolomide (TMZ), by blocking BER. First, we determined the specificity of NSC-124854 for Pol-β by examining in vitro activities of APE1, Fen1, DNA ligase I, and Pol-β-directed single nucleotide (SN)- and long-patch (LP)-BER. Second, we investigated the effect of NSC-124854 on the efficacy of TMZ to inhibit the growth of mismatch repair (MMR)-deficient and MMR-proficient colon cancer cell lines using in vitro clonogenic assays. Third, we explored the effect of NSC-124854 on TMZ-induced in vivo tumor growth inhibition of MMR-deficient and MMR-proficient colonic xenografts implanted in female homozygous SCID mice. Our data showed that NSC-124854 has high specificity to Pol-β and blocked Pol-β-directed SN- and LP-BER activities in in vitro reconstituted system. Furthermore, NSC-124854 effectively induced the sensitivity of TMZ to MMR-deficient and MMR-proficient colon cancer cells both in vitro cell culture and in vivo xenograft models. Our findings suggest a potential novel strategy for the development of highly specific structure-based inhibitor for the prevention of colonic tumor progression.
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Affiliation(s)
- Aruna S. Jaiswal
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Sanjeev Banerjee
- Barbara Ann Karmanos Cancer Institute, Department of Pathology, School of Medicine, Wayne State University, Detroit, Michigan, United States of America
| | - Ritu Aneja
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Fazlul H. Sarkar
- Barbara Ann Karmanos Cancer Institute, Department of Pathology, School of Medicine, Wayne State University, Detroit, Michigan, United States of America
| | - David A. Ostrov
- Department of Pathology, Immunology and Laboratory of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Satya Narayan
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Jaiswal AS, Banerjee S, Panda H, Bulkin CD, Izumi T, Sarkar FH, Ostrov DA, Narayan S. A novel inhibitor of DNA polymerase beta enhances the ability of temozolomide to impair the growth of colon cancer cells. Mol Cancer Res 2009; 7:1973-83. [PMID: 19996303 DOI: 10.1158/1541-7786.mcr-09-0309] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The recent emerging concept to sensitize cancer cells to DNA-alkylating drugs is by inhibiting various proteins in the base excision repair (BER) pathway. In the present study, we used structure-based molecular docking of DNA polymerase beta (Pol-beta) and identified a potent small molecular weight inhibitor, NSC-666715. We determined the specificity of this small molecular weight inhibitor for Pol-beta by using in vitro activities of APE1, Fen1, DNA ligase I, and Pol-beta-directed single-nucleotide and long-patch BER. The binding specificity of NSC-666715 with Pol-beta was also determined by using fluorescence anisotropy. The effect of NSC-666715 on the cytotoxicity of the DNA-alkylating drug temozolomide (TMZ) to colon cancer cells was determined by in vitro clonogenic and in vivo xenograft assays. The reduction in tumor growth was higher in the combination treatment relative to untreated or monotherapy treatment. NSC-666715 showed a high specificity for blocking Pol-beta activity. It blocked Pol-beta-directed single-nucleotide and long-patch BER without affecting the activity of APE1, Fen1, and DNA ligase I. Fluorescence anisotropy data suggested that NSC-666715 directly and specifically interacts with Pol-beta and interferes with binding to damaged DNA. NSC-666715 drastically induces the sensitivity of TMZ to colon cancer cells both in in vitro and in vivo assays. The results further suggest that the disruption of BER by NSC-666715 negates its contribution to drug resistance and bypasses other resistance factors, such as mismatch repair defects. Our findings provide the "proof-of-concept" for the development of highly specific and thus safer structure-based inhibitors for the prevention of tumor progression and/or treatment of colorectal cancer.
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Affiliation(s)
- Aruna S Jaiswal
- Department of Anatomy and Cell Biology and University of Florida Shands Cancer Center, University of Florida, Gainesville, FL 32610, USA
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Panda H, Jaiswal AS, Corsino PE, Armas ML, Law BK, Narayan S. Amino acid Asp181 of 5'-flap endonuclease 1 is a useful target for chemotherapeutic development. Biochemistry 2009; 48:9952-8. [PMID: 19769410 DOI: 10.1021/bi9010754] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
DNA alkylation-induced damage is one of the most efficacious anticancer therapeutic strategies. Enhanced DNA alkylation and weakened DNA repair capacity in cancer cells are responsible for the effectiveness of DNA-alkylating therapies. 5'-Flap endonuclease 1 (Fen1) is an important enzyme involved in base excision repair (BER), specifically in long-patch BER (LP-BER). Using the site-directed mutagenesis approach, we have identified an important role for amino acid Asp181 of Fen1 in its endonuclease activity. Asp181 is thought to be involved in Mg(2+) binding in the active site. Using structure-based molecular docking of Fen1 targeted to its metal binding pocket M2 (Mg(2+) site), we have identified a potent low-molecular weight inhibitor (LMI, NSC-281680) that efficiently blocks LP-BER. In this study, we have demonstrated that the interaction of this LMI with Fen1 blocked its endonuclease activity, thereby blocking LP-BER and enhancing the cytotoxic effect of DNA-alkylating agent Temozolomide (TMZ) in mismatch repair (MMR)-deficient and MMR-proficient colon cancer cells. The results further suggest that blockade of LP-BER by NSC-281680 may bypass other drug resistance mechanisms such as mismatch repair (MMR) defects. Therefore, our findings provide groundwork for the development of highly specific and safer structure-based small molecular inhibitors targeting the BER pathway, which can be used along with existing chemotherapeutic agents, like TMZ, as combination therapy for the treatment of colorectal cancer.
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Affiliation(s)
- Harekrushna Panda
- Department of Anatomy and Cell Biology and UF Shands Cancer Center, University of Florida, Gainesville, Florida 32610, USA
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Yamtich J, Sweasy JB. DNA polymerase family X: function, structure, and cellular roles. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1804:1136-50. [PMID: 19631767 DOI: 10.1016/j.bbapap.2009.07.008] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/02/2009] [Accepted: 07/03/2009] [Indexed: 10/20/2022]
Abstract
The X family of DNA polymerases in eukaryotic cells consists of terminal transferase and DNA polymerases beta, lambda, and mu. These enzymes have similar structural portraits, yet different biochemical properties, especially in their interactions with DNA. None of these enzymes possesses a proofreading subdomain, and their intrinsic fidelity of DNA synthesis is much lower than that of a polymerase that functions in cellular DNA replication. In this review, we discuss the similarities and differences of three members of Family X: polymerases beta, lambda, and mu. We focus on biochemical mechanisms, structural variation, fidelity and lesion bypass mechanisms, and cellular roles. Remarkably, although these enzymes have similar three-dimensional structures, their biochemical properties and cellular functions differ in important ways that impact cellular function.
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Affiliation(s)
- Jennifer Yamtich
- Department of Therapeutic Radiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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Abstract
Mutational inactivation of the tumor suppressor gene APC (Adenomatous polyposis coli) is thought to be an initiating step in the progression of the vast majority ofcolorectal cancers. Attempts to understand APC function have revealed more than a dozen binding partners as well as several subcellular localizations including at cell-cell junctions, associated with microtubules at the leading edge of migrating cells, at the apical membrane, in the cytoplasm and in the nucleus. The present chapter focuses on APC localization and functions in the nucleus. APC contains two classical nuclear localization signals, with a third domain that can enhance nuclear import. Along with two sets of nuclear export signals, the nuclear localization signals enable the large APC protein to shuttle between the nucleus and cytoplasm. Nuclear APC can oppose beta-catenin-mediated transcription. This down-regulation of nuclear beta-catenin activity by APC most likely involves nuclear sequestration of beta-catenin from the transcription complex as well as interaction of APC with transcription corepressor CtBP. Additional nuclear binding partners for APC include transcription factor activator protein AP-2alpha, nuclear export factor Crm1, protein tyrosine phosphatase PTP-BL and perhaps DNA itself. Interaction of APC with polymerase beta and PCNA, suggests a role for APC in DNA repair. The observation that increases in the cytoplasmic distribution of APC correlate with colon cancer progression suggests that disruption of these nuclear functions of APC plays an important role in cancer progression. APC prevalence in the cytoplasm of quiescent cells points to a potential function for nuclear APC in control of cell proliferation. Clear definition of APC's nuclear function(s) will expand the possibilities for early colorectal cancer diagnostics and therapeutics targeted to APC.
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Suehiro Y, Wong CW, Chirieac LR, Kondo Y, Shen L, Webb CR, Chan YW, Chan ASY, Chan TL, Wu TT, Rashid A, Hamanaka Y, Hinoda Y, Shannon RL, Wang X, Morris J, Issa JPJ, Yuen ST, Leung SY, Hamilton SR. Epigenetic-genetic interactions in the APC/WNT, RAS/RAF, and P53 pathways in colorectal carcinoma. Clin Cancer Res 2008; 14:2560-9. [PMID: 18451217 DOI: 10.1158/1078-0432.ccr-07-1802] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Early events in colorectal tumorigenesis include mutation of the adenomatous polyposis coli (APC) gene and epigenetic hypermethylation with transcriptional silencing of the O(6)-methylguanine DNA methyltransferase (MGMT), human mut L homologue 1 (hMLH1), and P16/CDKN2A genes. Epigenetic alterations affect genetic events: Loss of MGMT via hypermethylation reportedly predisposes to guanine-to-adenine or cytosine-to-thymine (G:C-->A:T) transition mutations in KRAS and P53, and silencing of hMLH1 leads to high levels of microsatellite instability (MSI-H)/mutator phenotype, suggesting that epigenetic-genetic subtypes exist. EXPERIMENTAL DESIGN We evaluated the relationships of aberrant methylation of APC, MGMT, hMLH1, P16, N33, and five MINTs to mutations in APC, KRAS, BRAF, and P53 in 208 colorectal carcinomas. RESULTS We found that APC hypermethylation was age related (P = 0.04), in contrast to the other genes, and did not cluster with CpG island methylator phenotype (CIMP) markers. Hypermethylation of APC concurrently with either MGMT or hMLH1 was strongly associated with occurrence of G-to-A transitions in APC [odds ratio (OR), 26.8; P < 0.0002 from multivariable logic regression model], but C-to-T transitions had no associations. There was no relationship of hypermethylation of any gene, including MGMT, with G-to-A or C-to-T transitions in KRAS or P53, although APC hypermethylation was associated with P53 mutation (P < 0.0002). CIMP with MSI-H due to hMLH1 hypermethylation, or CIMP with loss of MGMT expression in non-MSI-H tumors, was associated with BRAF mutation (OR, 4.5; P < 0.0002). CIMP was also associated with BRAF V600E T-to-A transversion (OR, 48.5; P < 0.0002). CONCLUSIONS Our findings suggest that the heterogeneous epigenetic dysregulation of promoter methylation in various genes is interrelated with the occurrence of mutations, as manifested in epigenetic-genetic subgroups of tumors.
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Affiliation(s)
- Yutaka Suehiro
- Department of Pathology, Division of Pathology and Laboratory Medicine, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
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34
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A novel function of adenomatous polyposis coli (APC) in regulating DNA repair. Cancer Lett 2008; 271:272-80. [PMID: 18662849 DOI: 10.1016/j.canlet.2008.06.024] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 04/07/2008] [Accepted: 06/11/2008] [Indexed: 11/22/2022]
Abstract
Prevailing literature suggests diversified cellular functions for the adenomatous polyposis coli (APC) gene. Among them a recently discovered unique role of APC is in DNA repair. The APC gene can modulate the base excision repair (BER) pathway through an interaction with DNA polymerase beta (Pol-beta) and flap endonuclease 1 (Fen-1). Taken together with the transcriptional activation of APC gene by alkylating agents and modulation of BER activity, APC may play an important role in carcinogenesis and chemotherapy by determining whether cells with DNA damage survive or undergo apoptosis. In this review, we summarize the evidence supporting this novel concept and suggest that these results will have implications for the development of more effective strategies for chemoprevention, prognosis and chemotherapy of certain types of tumors.
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35
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Wang Y, Azuma Y, Moore D, Osheroff N, Neufeld KL. Interaction between tumor suppressor adenomatous polyposis coli and topoisomerase IIalpha: implication for the G2/M transition. Mol Biol Cell 2008; 19:4076-85. [PMID: 18632987 DOI: 10.1091/mbc.e07-12-1296] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The tumor suppressor adenomatous polyposis coli (APC) is implicated in regulating multiple stages of the cell cycle. APC participation in G1/S is attributed to its recognized role in Wnt signaling. APC function in the G2/M transition is less well established. To identify novel protein partners of APC that regulate the G2/M transition, APC was immunoprecipitated from colon cell lysates and associated proteins were analyzed by matrix-assisted laser desorption ionization/time of flight (MALDI-TOF). Topoisomerase IIalpha (topo IIalpha) was identified as a potential binding partner of APC. Topo IIalpha is a critical regulator of G2/M transition. Evidence supporting an interaction between endogenous APC and topo IIalpha was obtained by coimmunoprecipitation, colocalization, and Förster resonance energy transfer (FRET). The 15-amino acid repeat region of APC (M2-APC) interacted with topo IIalpha when expressed as a green fluorescent protein (GFP)-fusion protein in vivo. Although lacking defined nuclear localization signals (NLS) M2-APC predominantly localized to the nucleus. Furthermore, cells expressing M2-APC displayed condensed or fragmented nuclei, and they were arrested in the G2 phase of the cell cycle. Although M2-APC contains a beta-catenin binding domain, biochemical studies failed to implicate beta-catenin in the observed phenotype. Finally, purified recombinant M2-APC enhanced topo IIalpha activity in vitro. Together, these data support a novel role for APC in the G2/M transition, potentially through association with topo IIalpha.
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Affiliation(s)
- Yang Wang
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA
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36
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McCartney BM, Näthke IS. Cell regulation by the Apc protein Apc as master regulator of epithelia. Curr Opin Cell Biol 2008; 20:186-93. [PMID: 18359618 DOI: 10.1016/j.ceb.2008.02.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/08/2008] [Accepted: 02/08/2008] [Indexed: 01/12/2023]
Abstract
The adenomatous polyposis coli (Apc) protein participates in many of the fundamental cellular processes that govern epithelial tissues: Apc is directly involved in regulating the availability of beta-catenin for transcriptional de-repression of Tcf/LEF transcription factors, it contributes to the stability of microtubules in interphase and mitosis, and has an impact on the dynamics of F-actin. Thus Apc contributes directly and/or indirectly to proliferation, differentiation, migration, and apoptosis. This particular multifunctionality can explain why disruption of Apc is especially detrimental for the epithelium of the gut, where Apc mutations are common in most cancers. We summarise recent data that shed light on the molecular mechanisms involved in the different functions of Apc.
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Affiliation(s)
- Brooke M McCartney
- Department of Biological Sciences, Carnegie Mellon University, 4400 5th Avenue, Pittsburgh, PA, USA
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37
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Kundu CN, Balusu R, Jaiswal AS, Gairola CG, Narayan S. Cigarette smoke condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells. Oncogene 2007; 26:1428-38. [PMID: 16924228 DOI: 10.1038/sj.onc.1209925] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 07/11/2006] [Accepted: 07/11/2006] [Indexed: 11/09/2022]
Abstract
Our previous studies have shown that treatment with cigarette smoke condensate (CSC) transforms normal breast epithelial cell line, MCF-10A. In the present study, the mechanism of CSC-induced transformation of breast epithelial cells was examined. We first determined whether benzo[a]pyrene (B[a]P)- and CSC-induced levels of APC are capable of inhibiting long-patch base excision repair (LP-BER) since our earlier studies had shown that an interaction of APC with DNA polymerase beta (pol-beta) blocks strand-displacement synthesis. With the use of a novel in vivo LP-BER assay, it was demonstrated that increased and decreased APC levels in different breast cancer cell lines were associated with a decrease or increase in LP-BER activity, respectively. The effect of APC on LP-BER in malignant and pre-malignant breast epithelial cell lines was produced by either overexpression or knockdown of APC. Furthermore, it was shown that the decreased LP-BER in B[a]P- or CSC-treated pre-malignant breast epithelial cells is associated with an increased level of APC and decreased cell growth. Our results suggest that the decreased growth allows cells to repair the damaged DNA before mitosis, and failure to repair damaged DNA has the potential to transform pre-malignant breast epithelial cells.
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Affiliation(s)
- C N Kundu
- Department of Anatomy and Cell Biology, UF Shands Cancer Center, University of Florida, Gainesville, FL 32610, USA
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38
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Jaiswal AS, Balusu R, Armas ML, Kundu CN, Narayan S. Mechanism of adenomatous polyposis coli (APC)-mediated blockage of long-patch base excision repair. Biochemistry 2006; 45:15903-14. [PMID: 17176113 PMCID: PMC2528549 DOI: 10.1021/bi0607958] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently, we found an interaction between adenomatous polyposis coli (APC) and DNA polymerase beta (pol-beta) and showed that APC blocks strand-displacement synthesis of long-patch base excision repair (LP-BER) (Narayan, S., Jaiswal, A. S., and Balusu, R. (2005) J. Biol. Chem. 280, 6942-6949); however, the mechanism is not clear. Using an in vivo LP-BER assay system, we now show that the LP-BER is higher in APC-/- cells than in APC+/+ cells. In addition to pol-beta, the pull-down experiments showed that the full-length APC also interacted with flap endonuclease 1 (Fen-1). To further characterize the interaction of APC with pol-beta and Fen-1, we performed a domain-mapping of APC and found that both pol-beta and Fen-1 interact with a 138-amino acids peptide from the APC at the DRI-domain. Our functional assays showed that APC blocks pol-beta-mediated 1-nucleotide (1-nt) as well as strand-displacement synthesis of reduced abasic, nicked-, or 1-nt gapped-DNA substrates. Further studies demonstrated that APC blocks 5'-flap endonuclease as well as the 5'-3' exonuclease activity of Fen-1 resulting in the blockage of LP-BER. From these results, we concluded that APC can have three different effects on the LP-BER pathway. First, APC can block pol-beta-mediated 1-nt incorporation and strand-displacement synthesis. Second, APC can block LP-BER by blocking the coordinated formation and removal of the strand-displaced flap. Third, APC can block LP-BER by blocking hit-and-run synthesis. These studies will have important implications for APC in DNA damage-induced carcinogenesis and chemoprevention.
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Affiliation(s)
| | | | | | | | - Satya Narayan
- Corresponding author – Satya Narayan, UF Shands Cancer Center, Cancer and Genetics Research Complex, Room 255, PO Box 103633, 1376 Mowry Road, University of Florida, Gainesville, FL 32610. Tel.: 352-273-8163; Fax: 352-273-8285; E-mail:
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Horton JK, Wilson SH. Hypersensitivity phenotypes associated with genetic and synthetic inhibitor-induced base excision repair deficiency. DNA Repair (Amst) 2006; 6:530-43. [PMID: 17113833 PMCID: PMC1911606 DOI: 10.1016/j.dnarep.2006.10.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Single-base lesions in DNA are repaired predominantly by base excision repair (BER). DNA polymerase beta (pol beta) is the polymerase of choice in the preferred single-nucleotide BER pathway. The characteristic phenotype of mouse fibroblasts with a deletion of the pol beta gene is moderate hypersensitivity to monofunctional alkylating agents, e.g., methyl methanesulfonate (MMS). Increased sensitivity to MMS is also seen in the absence of pol beta partner proteins XRCC1 and PARP-1, and under conditions where BER efficiency is reduced by synthetic inhibitors. PARP activity plays a major role in protection against MMS-induced cytotoxicity, and cells treated with a combination of non-toxic concentrations of MMS and a PARP inhibitor undergo cell cycle arrest and die by a Chk1-dependent apoptotic pathway. Since BER-deficient cells and tumors are similarly hypersensitive to the clinically used chemotherapeutic methylating agent temozolomide, modulation of DNA damage-induced cell signaling pathways, as well as BER, are attractive targets for potentiating chemotherapy.
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Affiliation(s)
| | - Samuel H. Wilson
- * Corresponding author. Tel.: 919-541-3267; fax: 919-541-3592. E-mail address: (S.H. Wilson)
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40
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Abstract
Base excision DNA repair (BER) is fundamentally important in handling diverse lesions produced as a result of the intrinsic instability of DNA or by various endogenous and exogenous reactive species. Defects in the BER process have been associated with cancer susceptibility and neurodegenerative disorders. BER funnels diverse base lesions into a common intermediate, apurinic/apyrimidinic (AP) sites. The repair of AP sites is initiated by the major human AP endonuclease, Ape1, or by AP lyase activities associated with some DNA glycosylases. Subsequent steps follow either of two distinct BER subpathways distinguished by repair DNA synthesis of either a single nucleotide (short-patch BER) or multiple nucleotides (long-patch BER). As the major repair mode for regular AP sites, the short-patch BER pathway removes the incised AP lesion, a 5'-deoxyribose-5-phosphate moiety, and replaces a single nucleotide using DNA polymerase (Polbeta). However, short-patch BER may have difficulty handling some types of lesions, as shown for the C1'-oxidized abasic residue, 2-deoxyribonolactone (dL). Recent work indicates that dL is processed efficiently by Ape1, but that short-patch BER is derailed by the formation of stable covalent crosslinks between Ape1-incised dL and Polbeta. The long-patch BER subpathway effectively removes dL and thereby prevents the formation of DNA-protein crosslinks. In coping with dL, the cellular choice of BER subpathway may either completely repair the lesion, or complicate the repair process by forming a protein-DNA crosslink.
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Affiliation(s)
- Jung-Suk Sung
- Department of Life Science, Dongguk University, Seoul, South Korea
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41
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Smirnova E, Toueille M, Markkanen E, Hübscher U. The human checkpoint sensor and alternative DNA clamp Rad9-Rad1-Hus1 modulates the activity of DNA ligase I, a component of the long-patch base excision repair machinery. Biochem J 2005; 389:13-7. [PMID: 15871698 PMCID: PMC1184534 DOI: 10.1042/bj20050211] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The human checkpoint sensor and alternative clamp Rad9-Rad1-Hus1 can interact with and specifically stimulate DNA ligase I. The very recently described interactions of Rad9-Rad1-Hus1 with MutY DNA glycosylase, DNA polymerase beta and Flap endonuclease 1 now complete our view that the long-patch base excision machinery is an important target of the Rad9-Rad1-Hus1 complex, thus enhancing the quality control of DNA.
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Affiliation(s)
- Ekaterina Smirnova
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Magali Toueille
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Enni Markkanen
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Ulrich Hübscher
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
- To whom correspondence should be addressed (email )
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Jaiswal AS, Balusu R, Narayan S. 7,12-Dimethylbenzanthracene-dependent transcriptional regulation of adenomatous polyposis coli (APC) gene expression in normal breast epithelial cells is mediated by GC-box binding protein Sp3. Carcinogenesis 2005; 27:252-61. [PMID: 16150893 DOI: 10.1093/carcin/bgi225] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the present investigation, we have examined the transcriptional regulation of adenomatous polyposis coli (APC) gene expression in the spontaneously immortalized human normal breast epithelial cell line, MCF10A, in response to carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) treatment. The APC mRNA levels and the APC gene's promoter (pAPCP) activity were increased in MCF10A cells after treatment with DMBA. A sequential deletion analysis and site-directed mutagenesis of the pAPCP promoter revealed that the DMBA response is mediated through a GC-box element. Also, the GC-box binding agent mithramycin A, which prevents binding of proteins to the GC-box region, abolished DMBA-mediated increase of the pAPCP promoter activity. The specificity of the proteins binding to the GC-box region was characterized by gel-shift analysis. An increased binding of the GC-box binding proteins was observed in the gel-shift analysis with nuclear extracts from DMBA-treated MCF10A cells, which corresponded to the increased levels of Sp1 and Sp3 proteins. However, a super-shift of the DNA-protein complexes was observed with only anti-Sp3 antibody. Based on the chromatin-immunoprecipitation assay results, the Sp3 appeared to be a genuine protein binding to the GC-box site of the pAPCP promoter. In RNA interference experiments, in which the Sp3 expression was knocked down, the DMBA response on the pAPCP promoter activity was reduced, suggesting that the binding of Sp3 to the GC-box site is critical for DMBA-induced pAPCP promoter activity. From these results we conclude that the increased pAPCP promoter activity in the MCF10A cell line in response to DMBA treatment is mediated by Sp3.
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Affiliation(s)
- Aruna S Jaiswal
- Department of Anatomy and Cell Biology and UF Shands Cancer Center, University of Florida, Gainesville, FL 32610, USA
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