Inhibition of ABCB1 expression overcomes acquired docetaxel resistance in prostate cancer

Menée sur des lignées cellulaires de cancer de la prostate, cette étude met en évidence le rôle joué par la surexpression de la protéine ABCB1 dans la résistance au docétaxel

Résumé en anglais

Docetaxel is the first-line standard treatment for castration resistant prostate cancer (CRPC). However, relapse eventually occurs due to the development of resistance to docetaxel. In order to unravel the mechanism of acquired docetaxel resistance, we established docetaxel-resistant prostate cancer cells, TaxR, from castration resistant C4-2B prostate cancer cells. The IC50 for docetaxel in TaxR cells was about 70-fold higher than parental C4-2B cells. Global gene expression analysis revealed alteration of expression of a total of 1604 genes with 52% being upregulated and 48% downregulated. ABCB1, which belongs to the ATP-binding cassette (ABC) transporter family, was identified among the top upregulated genes in TaxR cells. The role of ABCB1 in the development of docetaxel resistance was examined. Knockdown of ABCB1 expression by its specific shRNA or inhibitor resensitized docetaxel resistant TaxR cells to docetaxel treatment by enhancing apoptotic cell death. Furthermore, we identified that apigenin, a natural product of the flavone family, inhibits ABCB1 expression and resensitizes docetaxel resistant prostate cancer cells to docetaxel treatment. Collectively, these results suggest that overexpression of ABCB1 mediates acquired docetaxel resistance and targeting ABCB1 expression could be potential approach to resensitize docetaxel resistant prostate cancer cells to docetaxel treatment.