[RNA interference used for reversal of multi-drug resistance in leukemia cells -- review]

Chemotherapy remains at the first line for the treatment of leukemia. However, the multi-drug resistance of the tumor cells caused by chemotherapeutic drugs has seriously affected the effect of chemotherapy. And this is the main reason for the failure of the leukemia treatment. Therefore, to explore an effective way of reversing drug resistance has become the key of leukemia treatment. RNA interference, a system within living cells, helps to determine which genes are active and how active they are. It is a process in which translation of some cell messenger RNA (mRNA) sequences is prevented, because of the presence of (and consequent destruction of) matching double-stranded RNA sequences. RNA interference is also called post-transcriptional gene silencing (PTGS), since its effect on gene expression occurs after the production of mRNA during transcription. It is believed that RNA interference can protect the cell against viruses and other threats. The greatest advantage of RNAi is the specificity and high efficiency which can induce suppression of specific genes of interest but the unrelated genes are not affected. The selective and robust effect of RNAi on gene expression makes it a valuable research tool both in cell culture and living organisms because synthetic dsRNA introduced into cells can induce the suppression of specific genes of interest. Nowadays, the technology has been widely used in biomedical fields, especially in the diagnosis and treatment of blood system disease. However, besides the stability, targeting and biological safety in genetics, the immune response induced by exogenous RNA is also one of the key factors to limit the clinical practice of this emerging technology. In this review, the breakthrough of the technology in multi-drug resistance reversal in leukemia is summarized with the RNA interference technology as a starting point.