A mutation in β-tubulin and a sustained dependence on androgen receptor signalling in a newly established docetaxel-resistant prostate cancer cell line

The mechanisms of docetaxel resistance in PC (prostate cancer) are unclear because of the lack of suitable experimental models, and no effective treatment exists for docetaxel-resistant PC. We established a docetaxel-resistant cell line, LNDCr, from an androgen-refractory PC cell line, LNCaP-hr, by intermittent exposure to docetaxel in vitro. The LNDCr cells harboured an F270I mutation in class I beta-tubulin, and demonstrated impaired tubulin polymerization by docetaxel. AR signalling was sustained in LNDCr cells, and AR knockdown suppressed the growth of LNDCr cells. These results suggest that an acquired mutation in beta-tubulin is associated with docetaxel resistance in PC and that a novel AR-targeted therapy is effective for docetaxel-resistant PC.