Study of mechanism(s) of acquired doxorubicin resistance in human breast cancer cellsPenchatr Diskul Na Ayudthaya
( M.Sc. )
M.R. Jisnuson Svasti
Doxorubicin is considered as one of the first-line chemotherapies in breast cancer. Unfortunately, resistance to this agent continues to be a major problem in the treatment of breast cancer. Understanding the mechanism(s) underlying this resistance would be useful for the treatment and prognosis of cancer patients. In this study, we established doxorubicin resistant MDA-MB-231/DOXO subline from parental MDA-MB-231 human breast cancer cells. MDA-MB-231/DOXO was 100-fold more resistant to doxorubicin than its parental cells. It showed cross-resistance to taxol, vinblastine, etoposide and colchicine, but not to cisplatin, curcumin and fluorouracil (5-FU) compared to parental cells. Real-time PCR was used to identify resistance mechanisms and the overexpression of multidrug resistance 1 (MDR1) and glutathione-S-transferase-pi (GST) were shown in resistant cells as compared to those of parental cells. The overexpression of P-glycoprotein (P-gp) was confirmed by using immunoblotting and reversal assays. Moreover, proteomics was used to identify the alteration of proteins between parental and resistant cells in cellular, subcellular fractionated and secreted proteins. The decrease of glucose-6-phosphate dehydrogenase, nucleophosmin, group of histone proteins and heat shock proteins were found in total cellular proteins while the increase of peroxiredoxin II, peroxiredoxin IV, peroxiredoxin VI, breast cancer metastasis suppressor I, nucleolin, pyruvate kinase and annexin A2 were found in both cellular and subcellular proteins in resistant cells. In addition, we also found seven secreted proteins which have been reported to be involved in cancer resistance mechanisms including apolipoprotein E, laminin-binding protein, uncharacterized protein C17orf89 which were found only in parental cells, while ADAM metallopeptidase domain 22, fibronectin and annexin A2 were found only in resistant cells, and beta-2 microglobulin and serum albumin were found in both cell lines. The identified proteins may provide targets for the development of therapeutic agents and also in future cancer treatments in breast cancer cells.
Doxorubicin/ resistance/ human breast cancer/ MDA-MB-231/ cellular proteins/ subcellular fractionated/ secreted proteins/ proteomics