Expression of a drug resistance gene in human neuroblastoma cell lines: modulation by retinoic acid-induced differentiation.

摘要: Expression of a multidrug resistance gene (mdr1) and its protein product, P-glycoprotein (Pgp), has been correlated with the onset in vitro human cell lines selected for to chemotherapeutic agents derived from natural products. this also observed normal tissues tumors, including neuroblastoma. We therefore examined total RNA prepared neuroblastoma before after differentiation retinoic acid or sodium butyrate. An increase level mdr1 mRNA was treatment four lines, SK-N-SH line. Western blot (immunoblot) analysis demonstrated concomitant increases Pgp. However, studies 3H-vinblastine uptake failed show Pgp-mediated decrease cytotoxic drug accumulation. To provide evidence that Pgp localized on surface, an immunotoxin conjugate directed against added cells acid. Incorporation [3H]leucine decreased by acid-treated compared undifferentiated cells. These results demonstrate whereas expression can be modulated differentiating agents, increased levels are not necessarily associated