Abstract
Background: Multidrug resistance modifiers were indentified against ABC transporters such as ABCB1, but there are other resistance mechanisms based upon such transporters as CTR1 or ATP7A/B membrane proteins. Cisplatin resistance due to the lower expression of CTR1 or to the over-expression of ATP7A/B is also responsible for therapeutic failures in many cancer types.
Materials and Methods: 35 modified steroid derivatives were tested for their multidrug reversal and proliferation inhibitory activity comparing their effects in human ABCB1-transfected mouse T-cell lymphoma and cisplatin resistant human ovary carcinoma cell lines. The selected potent resistance reversal agents were tested in a checkerboard assay in the presence of the anticancer drug doxorubicin on mouse lymphoma or cisplatin on human ovary cancer cell lines.
Results: Correlations between chemical structure of different steroidal compounds on their effects on drug resistance were investigated. A common characteristic feature of D-ring substituents with N or O atom in the position of 1,3 was found within the effective inhibitors of proliferation when comparing the effective compounds on the two cancer cell lines.
Conclusion: We assume that the polar substituents forming a bidentate part may serve as a binding moiety on the polar protein-glycan surface of the cells and can result in an effect independent of the structure of the A ring.
Keywords: ABCB1, Cisplatin resistance, Human ovary carcinoma cell line, Modified steroids, Mouse T-cell lymphoma cell line, Multidrug resistance, ABC transporters, T-cell lymphoma, drug doxorubicin, ovary cancer cell, protein-glycan, copper transporter 1, amphipathic compounds, estrane, pregnenolone, enamino, Ureido, guanidino, Steraloids, Mass spectra, chloroform, pyridinium tosylate, boron trifluoride etherate, guanidinium chloride, p-amino-benzene-sulphonamide, sulphonamide, Pregnadienolon, hydrocortisone, sodium tetrahydroborate, bromocresol, Acetylation, cisplatin, foetal bovine serum, L-glutamine, antibiotics, thiazolyl blue tetrazolium bromide, Verapamil, colchicine
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