Error-prone translesion synthesis mediates acquired chemoresistance.
The development of cancer drug resistance is a persistent clinical problem limiting the successful treatment of disseminated malignancies. However, the molecular mechanisms by which initially chemoresponsive tumors develop therapeutic resistance remain poorly understood. Error-prone translesional DNA synthesis (TLS) is known to underlie the mutagenic effects of numerous anticancer agents, but little is known as to whether mutation induced by this process is ultimately relevant to tumor drug resistance. Here, we use a tractable mouse model of B-cell lymphoma to interrogate the role of error-prone translesional DNA synthesis in chemotherapy-induced mutation and resistance to front-line chemotherapy. We find that suppression of Rev1, an essential TLS scaffold protein and dCMP transferase, inhibits both cisplatin- and cyclophosphamide-induced mutagenesis. Additionally, by performing repeated cycles of tumor engraftment and treatment, we show that Rev1 plays a critical role in the development of acquired cyclophosphamide resistance. Thus, chemotherapy not only selects for drug-resistant tumor population but also directly promotes the TLS-mediated acquisition of resistance-causing mutations. These data provide an example of an alteration that prevents the acquisition of drug resistance in tumors in vivo. Because TLS also represents a critical mechanism of DNA synthesis in tumor cells following chemotherapy, these data suggest that TLS inhibition may have dual anticancer effects, sensitizing tumors to therapy as well as preventing the emergence of tumor chemoresistance.
Department of Biology, MIT, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Kun
K
Xie
Jason
J
Doles
Michael T
MT
Hemann
Graham C
GC
Walker
D000818:Animals; D002945:Cisplatin / Q000494:pharmacology / Q000627:therapeutic use; D003520:Cyclophosphamide / Q000494:pharmacology / Q000627:therapeutic use; D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004261:DNA Replication / Q000187:drug effects; D004259:DNA-Directed DNA Polymerase; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005260:Female; D016393:Lymphoma, B-Cell / Q000188:drug therapy / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D016296:Mutagenesis / Q000187:drug effects; D009713:Nucleotidyltransferases / Q000172:deficiency / Q000378:metabolism; D000099270:Y-Family DNA Polymerases
D002945:Cisplatin; D003520:Cyclophosphamide; D004247:DNA; D004259:DNA-Directed DNA Polymerase; D009713:Nucleotidyltransferases; C496086:Rev1 protein, mouse; D000099270:Y-Family DNA Polymerases