Targeted knockdown of Bcl2 in tumor cells using a synthetic TRAIL 3 '-UTR microRNA INTERNATIONAL JOURNAL OF CANCER Zhang, J., Huang, S., Zhang, H., Wang, H., Guo, H., Qian, G., Fan, X., Lu, J., Hoffman, A. R., Hu, J., Ge, S. 2010; 126 (9): 2229-2239

Abstract

Targeting tumor-related overexpression of anti-apoptotic Bcl2 protein by RNAi has been suggested as a potential treatment for cancer. However, the stability of RNAi and its delivery are still major obstacles to the clinical testing of Bcl2 RNAi. Here, we explore a novel strategy of expressing a synthetic Bcl2 microRNA (smRNA) in the 3' untranslated region (UTR) of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), an apoptosis-inducing protein without apparent toxic effects in normal cells. TRAIL was specifically expressed from the human telomerase reverse transcriptase promoter (pTRT) that is active in many human tumors. Using this approach, we demonstrated that pTRT drove the tumor-specific expression of Bcl2 smRNA, which was processed by the host RNAi machinery and silenced endogenous Bcl2 expression in tumor cells. Bcl2 smRNA induced tumor cell apoptosis by activating caspase-3 and led to significant sensitization of tumor cells to TRAIL-induced apoptosis, while normal cells were spared. We also showed that the combined therapy of TRAIL-induced apoptosis and Bcl2 downregulation was superior to the mono-therapy of TRAIL or Bcl2 smRNA alone. This study proves a general paradigm for cancer therapy by using 3' UTR microRNA technology.

View details for DOI 10.1002/ijc.24821

View details for Web of Science ID 000276173700022

View details for PubMedID 19676053

View details for PubMedCentralID PMC2924819