title: Fanconi anemia pathway heterogeneity revealed by cisplatin and oxaliplatin treatments.
abstract: Genetic or epigenetic inactivation of the pathway formed by the Fanconi Anemia (FA) proteins occurs in several cancer types, including head and neck squamous cell carcinomas (HNSCC), rendering the affected tumors potentially hypersensitive to DNA crosslinking agents. However, the cytotoxicity of other commonly used cancer therapeutics in cells with FA pathway defects remains to be defined. Here, we focused on the effects of cisplatin and oxaliplatin in a panel of HNSCC and fibroblast cell lines. We found that FANCC- and FANCD2-mutant cells were unexpectedly more sensitive to platinum drugs than FANCA-mutant cells, and mono-ubiquitination of FANCD2, which is mediated by the FANCA and FANCC containing FA core complex was not required for platinum resistance. Interestingly, platinum hypersensitivity could be dissociated from mitomycin C hypersensitivity suggesting different underlying mechanisms. FANCD2 or RAD51 subnuclear foci were not useful as biomarkers of platinum hypersensitivity of FANCC/FANCD2-mutant cells. Our data add to an emerging body of evidence indicating that the FA pathway is not linear and that several protein subcomplexes with different functions exist. It will be important to establish biomarkers that can predict the sensitivity of tumors with specific FA defects to chemotherapeutic agents.
authors.affiliation: Laboratory of Cellular and Molecular Radiation Oncology, Department of Radiation Oncology, Massachusetts General Hospital Cancer Center, Charlestown, MA 02129, USA. lisa.kachnic@bmc.org
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kachnic
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Loreen
authors.initials: L
authors.lastname: Fournier
authors.forename: Henning
authors.initials: H
authors.lastname: Willers
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D004351:Drug Resistance; D052217:Fanconi Anemia Complementation Group A Protein / Q000172:deficiency; D052218:Fanconi Anemia Complementation Group C Protein / Q000235:genetics; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000172:deficiency; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D009944:Organoplatinum Compounds / Q000494:pharmacology*; D000077150:Oxaliplatin
chemical_list: D000970:Antineoplastic Agents; D052217:Fanconi Anemia Complementation Group A Protein; D052218:Fanconi Anemia Complementation Group C Protein; D052236:Fanconi Anemia Complementation Group D2 Protein; D051856:Fanconi Anemia Complementation Group Proteins; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D002945:Cisplatin