miR193b Promotes Apoptosis of Gastric Cancer Cells via Directly Mediating the Akt Pathway

Figure 3

miR193b enhances apoptosis of GC cells by targeting KRAS. (a) miR193b has two binding sites in the 3UTR of the KRAS mRNA. (b) Wild-type or mutant versions of the KRAS 3UTR were cloned into the psiCHECK-2 vector. Renilla activities were measured in SGC-7901 cells cotransfected with miR193b and the KRAS-luciferase reporter. Position 303-309 of KRAS 3UTR was mutated in MUT1; Position 1074-1080 of KRAS 3UTR was mutated in MUT2; both two positions were mutated in MUT3. (c) KRAS protein expression decreased in SGC-7901 cells 48 hours after transfection with miR-193b. KRAS levels increased after transfection with miR193b-inhibitor. (d) Validation of the modified KRAS plasmid by Western blot assay. (e) Overexpression of KRAS reduces the apoptosis of SGC-7901 cells. (f) KRAS reduced miR193b-induced apoptosis in SGC-7901 cells. (g) Western blot analysis of KRAS, cleaved-caspase3, bax, and bcl-2 protein levels 48 hours after transfection with negative-control miRNA or miR193b or cotransfection with miR193b and KRAS. and were calculated using Student’s -test.

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