Inhibition of α Folate Receptor Resulting in a Reversal of Taxol Resistance in Nasopharyngeal Carcinoma

Abstract

Objective. To further determine the role of FOLR1 in taxol resistance of nasopharyngeal carcinoma (NPC) and whether inhibition of FOLR1 expression reverses the taxol-resistant phenotype.Study Design. Correlation study between gene expression and cancer cell survival.Setting. University hospital.Subjects and Methods. Three taxol-resistant sub–cell lines with a different resistant index were established from the parental CNE-1 NPC cell line. The correlation between FOLR1 expression and taxol sensitivity was statistically analyzed. Inhibition of FOLR1 expression was carried out by RNA interference and by a FOLR1-specific monoclonal antibody, and taxol sensitivity was examined by colony formation assays. FOLR1 expression was also examined in 72 NPC patient specimens by immunohistochemistry.Results. The levels of FOLR1 expression were positively and significantly correlated with a taxol resistance phenotype ( P < .05). Inhibition of FOLR1 expression resulted in a significantly increased sensitivity of taxol to taxol-resistant NPC cells ( P < .05). An increase of FOLR1 expression by gene transfection caused a taxol-resistant phenotype in parental NPC cells. The level of FOLR1 expression was found to be related to clinical stage in NPC tissue samples.Conclusion. These results suggest that FOLR1 plays an important role in taxol resistance of NPC cells.