Characterization of acquired paclitaxel resistance of breast cancer cells and involvement of ABC transporters.
Development of taxane resistance has become clinically very important issue. The molecular mechanisms underlying the resistance are still unclear. To address this issue, we established paclitaxel-resistant sublines of the SK-BR-3 and MCF-7 breast cancer cell lines that are capable of long-term proliferation in 100nM and 300nM paclitaxel, respectively. Application of these concentrations leads to cell death in the original counterpart cells. Both sublines are cross-resistant to doxorubicin, indicating the presence of the MDR phenotype. Interestingly, resistance in both paclitaxel-resistant sublines is circumvented by the second-generation taxane SB-T-1216. Moreover, we demonstrated that it was not possible to establish sublines of SK-BR-3 and MCF-7 cells resistant to this taxane. It means that at least the tested breast cancer cells are unable to develop resistance to some taxanes. Employing mRNA expression profiling of all known human ABC transporters and subsequent Western blot analysis of the expression of selected transporters, we demonstrated that only the ABCB1/PgP and ABCC3/MRP3 proteins were up-regulated in both paclitaxel-resistant sublines. We found up-regulation of ABCG2/BCRP and ABCC4 proteins only in paclitaxel-resistant SK-BR-3 cells. In paclitaxel-resistant MCF-7 cells, ABCB4/MDR3 and ABCC2/MRP2 proteins were up-regulated. Silencing of ABCB1 expression using specific siRNA increased significantly, but did not completely restore full sensitivity to both paclitaxel and doxorubicin. Thus we showed a key, but not exclusive, role for ABCB1 in mechanisms of paclitaxel resistance. It suggests the involvement of multiple mechanisms in paclitaxel resistance in tested breast cancer cells.
Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic. Electronic address: vlasta.furstova@lf3.cuni.cz.
Vlasta
V
Němcová-Fürstová
Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Dana
D
Kopperová
Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Kamila
K
Balušíková
Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic.
Marie
M
Ehrlichová
Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic.
Veronika
V
Brynychová
Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic.
Radka
R
Václavíková
Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Petr
P
Daniel
Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic.
Pavel
P
Souček
Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
Jan
J
Kovář
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D000089762:Multidrug Resistance-Associated Protein 2; D017239:Paclitaxel / Q000494:pharmacology*
C000715087:ABCC2 protein, human; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D000089762:Multidrug Resistance-Associated Protein 2; D017239:Paclitaxel
ABC transporter; ABCB1; Breast cancer cells; Doxorubicin; Paclitaxel resistance; Taxane SB-T-1216