MicroRNA-451Acts As A Tumour Suppressor By Down-regulating IL6R Pathway

Aim The miR-451was found to be down-regulated frequently in tumours, indicatingthat miR-451could play a big role in carcinogenesis. This study uncovered themechanism by which the miR-451functions as a tumour suppressor.Methods The target genes of miR-451were predicted using target gene predictionsoftwares. Then the miR-451mimics were introduced into RKO and Hela cellsrespectively. The proliferation and invasion of cells were monitored by MTT, cellcycle and in vitro extracellular matrix invasion assays. Also the angiogenesis ofHUVEC cells transfected with miR-451mimics was examined. In the meantime,IL6R, the predicted target gene of miR-451, was studied by real time PCR, westernblotting, and siRNA technologies.Results The mRNA and protein levels of IL6R gene were found to be down-regulatedin the RKO and Hela cells transfected with miR-451mimics. Meanwhile, the cellproliferation was inhibited. Also the invasion of RKO cells was suppressed.Furthermore, the angiogenesis of HUVEC cells transfected with miR-451mimics wasassayed and the decreased angiogenic ability was seen compared to the controls. Theall of results above were validated by the IL6R siRNA experiments.Conclusions The IL6R gene is a target gene of miR-451. The miR-451behaves as atumour suppressor probably by down-regulating IL6R pathway.