RNA interference--about the reality to be exploited in cancer therapy

The discovery of RNA interference (RNAi) in mammalian cells raises the expectations of gene therapy, especially in cancer. However, it is too early to say how great this promise may be because of many disputable problems including intracellular delivery of siRNA, the transient nature of RNAi and potential side effects after long-term treatment. The present microarray study demonstrates that the RNAi of one oncogene (encoding bcr-abl fusion protein in chronic myelogenous leukemia) triggers an overexpression of other "sleeping" oncogenes, antiapoptotic genes and factors, preserving the immortalization of bcr-abl-positive leukemia cells.