title: Evaluation of candidate biomarkers to predict cancer cell sensitivity or resistance to PARP-1 inhibitor treatment.
abstract: Impaired DNA damage response pathways may create vulnerabilities of cancer cells that can be exploited therapeutically. One such selective vulnerability is the sensitivity of BRCA1- or BRCA2-defective tumors (hence defective in DNA repair by homologous recombination, HR) to inhibitors of the poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme critical for repair pathways alternative to HR. While promising, treatment with PARP-1 inhibitors (PARP-1i) faces some hurdles, including (1) acquired resistance, (2) search for other sensitizing, non-BRCA1/2 cancer defects and (3) lack of biomarkers to predict response to PARP-1i. Here we addressed these issues using PARP-1i on 20 human cell lines from carcinomas of the breast, prostate, colon, pancreas and ovary. Aberrations of the Mre11-Rad50-Nbs1 (MRN) complex sensitized cancer cells to PARP-1i, while p53 status was less predictive, even in response to PARP-1i combinations with camptothecin or ionizing radiation. Furthermore, monitoring PARsylation and Rad51 foci formation as surrogate markers for PARP activity and HR, respectively, supported their candidacy for biomarkers of PARP-1i responses. As to resistance mechanisms, we confirmed the role of the multidrug resistance efflux transporters and its reversibility. More importantly, we demonstrated that shRNA lentivirus-mediated depletion of 53BP1 in human BRCA1-mutant breast cancer cells increased their resistance to PARP-1i. Given the preferential loss of 53BP1 in BRCA-defective and triple-negative breast carcinomas, our findings warrant assessment of 53BP1 among candidate predictive biomarkers of response to PARPi. Overall, this study helps characterize genetic and functional determinants of cellular responses to PARP-1i and contributes to the search for biomarkers to exploit PARP inhibitors in cancer therapy.
authors.affiliation: Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Lenka
authors.initials: L
authors.lastname: Oplustilova
authors.forename: Kamila
authors.initials: K
authors.lastname: Wolanin
authors.forename: Martin
authors.initials: M
authors.lastname: Mistrik
authors.forename: Gabriela
authors.initials: G
authors.lastname: Korinkova
authors.forename: Dana
authors.initials: D
authors.lastname: Simkova
authors.forename: Jan
authors.initials: J
authors.lastname: Bouchal
authors.forename: Rene
authors.initials: R
authors.lastname: Lenobel
authors.forename: Jirina
authors.initials: J
authors.lastname: Bartkova
authors.forename: Alan
authors.initials: A
authors.lastname: Lau
authors.forename: Mark J
authors.initials: MJ
authors.lastname: O'Connor
authors.forename: Jiri
authors.initials: J
authors.lastname: Lukas
authors.forename: Jiri
authors.initials: J
authors.lastname: Bartek
mesh_terms: D017766:Acid Anhydride Hydrolases; D000970:Antineoplastic Agents / Q000494:pharmacology; D019313:BRCA1 Protein / Q000235:genetics / Q000378:metabolism; D024682:BRCA2 Protein / Q000235:genetics / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D002277:Carcinoma / Q000188:drug therapy*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004249:DNA Damage; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005720:Gamma Rays / Q000627:therapeutic use; D015972:Gene Expression Regulation, Neoplastic; D019450:Genes, MDR; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D000076228:MRE11 Homologue Protein; D008297:Male; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics* / Q000378:metabolism; D059767:Recombinational DNA Repair / Q000187:drug effects / Q000528:radiation effects; D000071857:Tumor Suppressor p53-Binding Protein 1
chemical_list: D000970:Antineoplastic Agents; D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human; D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; C121766:MRE11 protein, human; C112156:NBN protein, human; D009687:Nuclear Proteins; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1; C499320:PARP1 protein, human; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D000076228:MRE11 Homologue Protein; D017766:Acid Anhydride Hydrolases; C112158:RAD50 protein, human; D045643:DNA Repair Enzymes; D002166:Camptothecin