Research Of MiR-551b On The Effect Of Biological Behavior Of Gastric Cancer Cell

Objective To investigate the effect of miR-551b on the invasive, metastatic and apoptosis of gastric cancerMethods The potential target-gene for miR-551b-3p was analyzed by four miRNA target-gene prediction websites:miRbase, miRwalk, miRanda and Targetscan human. With fluorescent markers of chemical synthesis of the mimics of miR-551b-3p was transfected into MKN-45gastric cancer cell line by Lipofectmine2000TM, Using the fluorescent inverted microscope to observe the intracellular fluorescence, In transfection group cell and the control group cell was respectively detected the expression of miR-551b-3p and the expression level of target-gene mRNA by qRT-PCR. The protein level of target-gene regulated by miR-551b-3p was detected by Western Blot experiment.The proportion of apoptotic cells in MKN-45cells transfect with miR-551b-3p mimics was assessed by FACS analyses."Scratch wound healing"and transwell with or without matrigel was used to investigate the impact of miR-551b-3p on migratory and invasive abilities of MKN-45cells.Result①Use qRT-PCR to detect the expression of miR-551b-3p,the miR-551b-3p transfected group was277.5fold of the control group, So the transfected miR-551b-3p mimics was expressed successfully, the PAK4mRNA expression level was1.145fold of the control group.②Extracted protein do Western Blot experiment after48h,the PAK4protein expression level of the transfected miR-551b-3p mimics group was lower than in control groups.③We assayed the polarized migration of MKN-45cell using "Scratch wound healing" assay. After24h,the transfection miR-551b-3p mimics cell group compared with control groups, the scratch width was no obvious change between the groups. But after48h, the transfection miR-551b-3p mimics cell group compared with control groups, the scratch width was obvious change between these groups. MKN-45cell transfected with miR-551b-3p mimics closed the scratch wound more slowly than these groups.④Transwell with or without matrigel results showed that overexpression of miR-551b-3p significantly inhibited migratory and invasive numbers of MKN-45cells.⑤The proportion of apoptotic cells in MKN-45cell transfected of miR-551b-3p mimics was20.95%,and in the control group cell was3.19%.There are significant differences between the two groups.Conclusion The PAK4may be a target gene of miR-551b-3p,in gastric cancer cell MKN-45,miR-551b-3p can inhibit the protein expression of PAK4.Overexpression of miR-551b-3p can significantly reduce the invasion and migration ability of gastric cancer cell,and can promote cell apoptosis.