title: Inhibition of ABCB1 expression overcomes acquired docetaxel resistance in prostate cancer.
abstract: Docetaxel is the first-line standard treatment for castration-resistant prostate cancer. However, relapse eventually occurs due to the development of resistance to docetaxel. 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 1,604 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 a potential approach to resensitize docetaxel-resistant prostate cancer cells to docetaxel treatment.
authors.affiliation: Corresponding Author: Allen C. Gao, Department of Urology, University of California Davis Medical Center, 4645 2nd Ave, Research III, Suite 1300, Sacramento, CA 95817. acgao@ucdavis.edu.
authors.forename: Yezi
authors.initials: Y
authors.lastname: Zhu
authors.forename: Chengfei
authors.initials: C
authors.lastname: Liu
authors.forename: Nagalakshmi
authors.initials: N
authors.lastname: Nadiminty
authors.forename: Wei
authors.initials: W
authors.lastname: Lou
authors.forename: Ramakumar
authors.initials: R
authors.lastname: Tummala
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Evans
authors.forename: Allen C
authors.initials: AC
authors.lastname: Gao
mesh_terms: D000074063:ATP Binding Cassette Transporter, Subfamily D, Member 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D047310:Apigenin / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D058990:Molecular Targeted Therapy; D009364:Neoplasm Recurrence, Local; D064129:Prostatic Neoplasms, Castration-Resistant / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D043823:Taxoids / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: C115572:ABCD1 protein, human; D000074063:ATP Binding Cassette Transporter, Subfamily D, Member 1; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D043823:Taxoids; D000077143:Docetaxel; D047310:Apigenin