Synthetic Tet-inducible artificial microRNAs targeting β-catenin or HIF-1α inhibit malignant phenotypes of bladder cancer cells T24 and 5637

Ribonucleic acid interference (RNAi) based on microRNA (miRNA) may provide efficient and safe therapeutic opportunities. However, natural microRNAs can not easily be regulated and usually cause few phenotypic changes. Using the engineering principles of synthetic biology, we provided a novel and standard platform for the generation of tetracycline (Tet)-inducible vectors that express artificial microRNAs in a dosage-dependent manner. The vector generates a Pol II promoter-mediated artificial microRNA which was flanked by ribozyme sequences. In order to prove the utility of this platform, we chose β-catenin and HIF-1α as the functional targets and used the bladder cancer cell lines 5637 and T24 as the test models. We found that the Tet-inducible artificial microRNAs can effectively silence the target genes and their downstream genes, and induce anti-cancer effects in the two bladder cancer cell lines. These devices can inhibit proliferation, induce apoptosis, and suppress migration of the bladder cancer cell lines 5637 and T24. The Tet-inducible synthetic artificial microRNAs may represent a kind of novel therapeutic strategies for treating human bladder cancer.