Altered gene expression in drug-resistant human breast cancer cells.

摘要: It is increasingly recognized that drug-resistant cells undergo transitions not directly linked to "classical" drug resistance. We examined the expression of growth factors, factor receptors, and estrogen receptor in 17 2 revertant human breast cancer sublines provide an understanding phenotypic changes occur how these could affect biology cell. These were derived from five parental cell lines (MCF-7, ZR75B, T47D, MDA-MB-231, MDA-MB-453). The was absent or decreased 6 15 resistant MCF-7, T47D sublines. Increases as much 49-fold compared levels observed transforming alpha, epidermal receptor, c-erbB2, and/or c-erbB3 mRNA 14 Altered amphiregulin insulin-like factor-I nine four sublines, respectively. No major alterations c-erbB4 expression. Few two receptor-negative cells. Higher phosphotyrosine residues detected a subset indicating increased tyrosine kinase activity Interestingly, rates all despite up-regulated factor-related gene Taken together, data suggest loss pathway genes, rate regularly Although we do know whether altered genes cause consequence reduced rate, it well established confers serve initiate, support, extend