Экспрессия генов изоформ тиоредоксина и тиоредоксинредуктазы при формировании лекарственной устойчивости опухолевых клеток к доксорубицину

Проведена оценка экспрессии генов изоформ тиоредоксина и тиоредоксинредуктазы при формировании лекарственной устойчивости опухолевых клеток к доксорубицину. Показано, что у резистентных к DOX опухолевых клеток K562/DOX, MCF-7/DOX, SKVLB обнаружен рост экспрессии генов TRX2 и TRXRD1, тогда как повышение экспрессии гена TRX1 установлено только в клетках SKVLB. Во всех трех типах резистентных клеток обнаружен рост активности как Trx, так и TrxR. Увеличение экспрессии генов, контролирующих систему Trx/TrxR, в значительной степени можно расценивать как важную часть адаптивного антиоксидантного ответа в редокc-зависимом механизме развития резистентности исследуемых линий опухолевых клеток к DOX.

Expression of genes encoding isoforms of thioredoxin and thioredoxin reductase under development of cancer cell resistance to doxorubicin

Redox-dependent processes substantially influence the functional activity of many proteins and participate in regulation of the most important vital processes of the cell such as proliferation, differentiation, and apoptosis. Investigation of regulation of intracellular thiol-disulfide balance by thioredoxin/thioredoxin reductase system is actual now. The aim of the research was a study of expression of genes encoding isoforms of thioredoxin (Trx) and thioredoxin reductase (TrxR) under development of cancer cell resistance to doxorubicin (DOX). The cell lines were used in the study: human erythroleukemia K562, human breast carcinoma MCF-7 and human ovarian carcinoma SKOV-3 - DOX-sensitive cells (K562/S, MCF-7/S, SKOV-3 с IC50 - 0,35, 1,1, 0,2 µМ respectively) and DOX-resistant cells (K562/DOX, MCF-7/DOX, SKVLB с IC50 - 5,2, 25, 1,6 µМ respectively). Level of mRNA was determined using qRT-PCR. Electrophoresis of PCR products was conducted in 1,5-2% agarose gel followed by densitometry. Gel analysis was performed using the BioCaptMW software (Vilber Lourmat). Activity of Trx and TrxR was estimated by spectrophotometry assays. Growth of expression of TRX2 and TRXRD1genes was found in DOX-resistant K562/DOX, MCF-7/DOX, SKVLB cells whereas an increase of expression of TRX1gene was detected only in SKVLB cells. Elevation of Trx and TrxR activity was observed in all three types of resistant cells. The growth of expression of genes controlled Trx/TrxR system may be estimated as the important part of adaptive antioxidant response in redox-dependent mechanism of development of the cancer cells resistance to DOX.