MiR-145 Suppresses The Proliferation And Invasion Of Breast Cancer MCF-7 Cells Through Targeting ADAM17

Objectives To observe the effect of mi R-145 on the proliferation and invasion of human breast cancer MCF-7 cell line, and explore the relationship between mi R-145 and ADAM17、EGFR.Methods 1 Using mi RN A target gene prediction software to search for possible regulatory effects of mi RNA on ADAM17. 2 The experiment was divided into 3 groups: control group(normal MCF-7 cells), nonsense sequence group(MCF-7 cells with transfected NC) and transfection group(MCF-7 cells with transfected mi R-145 mimics). 3 Real- time PCR was used to detect the mi R-145 transfection efficiency in each group. 4 The proliferation ability of the cells was detected by MTT. 5 The invasion ability of the cells was detected by Transwell invasion assay. 6 The m RN A and protein expression of ADAM17、EGFR in each group were detected by real-time PCR and western blot, respectively.Results 1 Online target gene prediction results showed that there was continuous base complementation between mi R-145 5’ terminal region and ADAM17 m RNA 3’ end region. 2 Real- time PCR results showed that the expression of mi R-145 in transfeciton group(13964.33±1265.30) was significantly higher than that in control group(1.00±0.05, P<0.01) and NC group(1.03±0.15, P<0.01). The expression of ADAM17 m RNA in transfeciton group(1.71±0.08) was significantly higher than that in control group(1.00±0.07, P<0.01), but there was no difference in ADAM17 m RNA expression between control group and NC group(1.61±0.12, P > 0.05). The expression of EGFR m RNA in control group, NC group and transfection group was 1.00±0.08, 1.04±0.09, 1.05±0.09, respectively. There was no statistical differences in three groups(P >0.05). 3 The results of MTT showed that the proliferation ability of transfected group was significantly lower than that of control group and NC group in 24, 48 and 72h(P < 0.01). The inhibition rate curve also showed that the inhibition rate of transfection group increased with time and reached the maximum value at 72h(46%). 4 Transwell invasion assay results showed that the number of transmembrane cells in transfection group, NC group and control group was 56.20±2.17, 91.80±4.97, 92.80±3.90/vision, respectively. The invasion ability of transfec tion group was significantly lower than that in control group and NC group(P<0.01). 5 Western blot results showed that the expression of ADAM17 and EGFR in control group, NC group and transfection group was 0.302±0.023, 0.307±0.017, 0.185±0.015 and 0.337±0.039, 0.315±0.015, 0.083±0.009, respectively. The expression of ADAM17 and EGFR protein in transfeciton group were significantly lower than that in control group and NC group(P<0.01).Conclusions mi R-145 can significantly inhibit the proliferation and invasion of breast cancer MCF-7 cells, which inhibitory effect is achieved through the target ADAM17 and its downstream EGFR pathway.