Infection of H69AR cells with retroviral particles harboring interfering RNAi significantly reduced the multidrug resistance of these small cell lung cancer cells

Kanagaraj Palaniyandi, Qing Zhao, Xiu Bao Chang

Research output: Contribution to journalArticle

6 Scopus citations


Incubation of the drug-sensitive H69, a small cell lung cancer cell line, with increased concentrations of adriamycin yielded multidrug resistant (MDR) H69AR cells that over-express multidrug resistance-associated protein (MRP1). MRP1 co-transports its substrate with glutathione (GSH), leading to lower intracellular GSH. In this report we tested whether depleting intracellular GSH in MRP1-expressing cells could hyper-sensitize them to anticancer drugs or not. We have found that the GSH contents in MRP1-expressing cells are significantly lower than their corresponding control cells. The treatment with MRP1 substrate verapamil or the GSH synthetase inhibitor buthionine sulfoximine significantly reduced the intracellular GSH contents in MRP1-expressing cells. Interestingly, depleting intracellular GSH contents can hyper-sensitize the MRP1-cDNA transfected BHK cells to daunomycin, but not the adriamycinselected H69AR cells. Further analyses indicated that anti-apoptotic factor Bcl2 might be a factor responsible for the fact that depleting intracellular GSH could not hyper-sensitize H69AR cells to daunomycin. We hypothesized that knocking down the expression of Bcl2 could hyper-sensitize H69AR cells to daunomycin. Interestingly, infection of H69AR cells with retroviral particles harboring Bcl2 interfering RNAi not only reduced the expression of Bcl2, but also many factors that contribute to MDR, such as Bcl-xL, MRP1 and ABCC3, etc., leading to the MDR H69AR cells more sensitive to daunomycin than the parental H69 cell. Thus, although the mechanisms of the down-regulation of the genes contributing to MDR remain to be elucidated, retroviral particles harboring Bcl2 interfering RNAi could be used as an alternative way to sensitize the MDR cancer cells to anticancer drugs.

Original languageEnglish (US)
Pages (from-to)155-167
Number of pages13
JournalInternational Journal of Biochemistry and Molecular Biology
Issue number2
StatePublished - Jun 10 2011



  • Bcl2
  • Glutathione (GSH)
  • MRP1
  • Multidrug resistance (MDR)
  • PCR array
  • Small cell lung cancer (SCLC)
  • Small interfering RNAi

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

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