MicroRNA EXPRESSION PROFILES OF HEAD AND NECK SQUAMOUS CELL CARCINOMA WITH DOCETAXEL-INDUCED MULTIDRUG RESISTANCE

Background. The purpose of this study was to investigate the potential role of variable microRNA (miRNA) expression in the development of multidrug resistance (MDR) in head and neck cancer. Methods. Head and neck squamous cell carcinoma cell lines UMSCC-1 and SQ20B were treated with docetaxel at increasing concentrations to develop resistant cell lines. Parental and resistant cells were treated with cisplatin, 5-fluorouracil, paclitaxel, methotrexate, and doxorubicin to confirm cross-resistance. The miRNA pattern of resistant cells was then compared with their parental cells. Results. Docetaxel treatment successfully induced resistance primarily and induced multidrug cross-resistance. Resistant cells showed significant downregulation of miR-100, miR-130a, and miR-197 and upregulation in miR-101, miR-181b, miR-181d, and miR-195 expression when compared with their parent cells (p < .01). Real-time polymerase chain reaction (PCR) analysis confirmed statistically significant downregulation in miR-100 and miR-130a and upregulation in miR-181d expression (p < .001). Conclusion. Alterations in miRNA expression has direct relationship to MDR in head and neck cancer and may serve as biomolecular targets for reversal of MDR. (C) 2010 Wiley Periodicals, Inc. Head Neck 33: 786-791, 2011