Up/down-regulation of miR-21 changes biological function of colon can-cer cells and sensitivity to cetuximab / 中国病理生理杂志

ABSTRACT

AIM:To explore the effects of miR-21 on biological behavior of colon cancer cells and their sensi-tivity to epidermal growth factor receptor monoclonal antibody cetuximab .METHODS:Lentiviral vectors were constructed to generate up-and down-regulations of miR-21 lentiviruses (LV-miR-21 and LV-anti-miR-21, respectively), and the cor-responding negative control viruses (LV-miR-21 NC and LV-anti-miR-21 NC, respectively) were also constructed.The vi-ruses were used to infect human colon cancer RKO cells .The changes of the miR-21 expression level , the cell prolifera-tion, the colony-forming ability, the cell apoptosis and the sensitivity of the cells to cetuximab were detected by real -time PCR, MTT assay, soft agar colony assay , flow cytometry and CCK-8 assay.RESULTS: The lentivirus titers of LV-miR-21, LV-miR-2 NC, LV-anti-miR-21 and LV-anti-miR-21 NC were 3.0 ×1012 TU/L, 6.0 ×1011 TU/L, 2.0 ×1012 TU/L and 8.0 ×1011 TU/L, respectively.The infection efficiency was over 80% by the observation of green fluorescence .The miR-21 expression level , the cell proliferation , and the colony-forming ability in LV-miR-21 group were significantly higher than those in LV-anti-miR-21 group.The early apoptotic rate and the inhibitory rate of cetuximab for the cells in LV-anti-miR-21 group were higher than those in LV-miR-21 group.CONCLUSION: miR-21 promotes the proliferation of colon cancer cells.Down-regulation of miR-21 enhances the sensitivity of the colon cancer cells to the targeted therapy drug cetuximab.