Effects Of MiR-98 On Proliferation, Apoptosis, Invasion And Migration Of Hepatocellular Carcinoma HepG2 Cells

Backgroud: Hepatocellular carcinoma(HCC) is one of the common malignant tumors in digestive system, particularly high incidence in our country.At present, surgical resection is still the main treatment, but the surgical resection is high risk, low efficiency.And hepatocellular carcinoma is not sensitive to radiotherapy and chemotherapy, the systemic overall effectiveness is also less than 10%,therefore, the discovery of new diagnostic markers and therapeutic targets has become the key to explore the treatment and prognosis of hepatocellular carcinoma. Several studies have confirmed that the abnormal expression of small RNA(mi RNAs) is closely related to the occurrence and development of hepatocellular carcinoma,the intensive study of the function and the related mechanism of mi RNAs in HCC may provide new ideas for the treatment of HCC in a certain degree. The research group tested the mi RNA expression profile of Hep G2 cells using mi RNA array, and found that the expression level of mi R-98 significantly down-regulated in Hep G2 cells compared with normal liver cells. This study was designed to change the expression level of mi R-98 in Hep G2 cells by transfection technology and looked for the effects of mi R-98 on Hep G2 cells,to explore the role of mi R-98 in the occurrence and development in liver cancer, in order to find new therapeutic target to lay the theoretical foundation.Objectives: To study the effects of mi R-98 on proliferation, apoptosis,invasion and migration of hepatocellular carcinoma Hep G2 cells, and its possible mechanism.Method:1.The Lipofectamine 3000 and mi R-98 mimics were in accordance with the different proportion.The transfection efficiency was tested by the Taqman real-time fluorescent quantitative polymerase chain reaction(PCR) 24 h post-transfection.2.Mi R-98 mimics,mi R-98 inhibitor were transfected into Hep G2 cells using Lip ofectamine 3000. The transfection efficiency was detected by Taqman q RT-PCR24 h post-transfection.3.The effects of mi R-98 mimics,mimics-NC,mi R-98 inhibitor,inhibitor-NC on cell proliferation was determind by MTT assay.4.The effects of mi R-98 mimics,mimics-NC,mi R-98 inhibitor,inhibitor-NC on cell proliferation was tested by Annexin V-FITC / PI.5.The effects of mi R-98 mimics,mimics-NC,mi R-98 inhibitor,inhibitor-NC on cell migration ability was tested by Transwell migration assay.6.The effects of mi R-98 mimics,mimics-NC,mi R-98 inhibitor,inhibitor-NC on cell invasion ability was tested by Transwell invasion assay.7.The effects of mi R-98 mimics,mimics-NC,mi R-98 inhibitor,inhibitor-NC on expression of apoptosis protein Bcl- 2 was tested by Western blot assay.Results:1. Mi R-98 in mi RNAs minics: Lipo3000 = 1:5 group has the highest expression level in cells, 33.36573 times as much as the control group.2. q RT-PCR results showed that the relative expression level of mi R-98 in mi R-98 mimics group and mi R-98 inhibitor group was respectively(34.81±4.80) and(0.33±0.03) times as much as the blank control group 24 h post-transfection.3. MTT assay demonstrated that, the cell survival rate of mi R-98 mimics group was lower than the blank control group and mimics-NC group(P<0.05);the cell survival rate of mi R-98 inhibitor group was higher than the blank control group and inhibitor-NC group(P<0.05).4. Flow cytometry showed that the cell apoptosis rate of mi R-98 mimics group was significantly higher than the blank control group and mimics-NC group(P<0.05); the cell apoptosis rate of mi R-98 inhibitor group was lower than the blank control group and inhibitor-NC group(P<0.05).5. Transwell migration assay showed that the number of Hep G2 cells that spenetrated into the lower chamber in mi R-98 mimics group was less than the blank control group and mimics-NC group(P<0.05),while the number of Hep G2 cells that spenetrated into the lower chamber in mi R-98 inhibitor group was significantly more than the blank control group and inhibitor-NC group(P<0.05).6. Transwell invasion assay showed that the number of Hep G2 cells that spenetrated into the lower chamber in mi R-98 mimics group was less than the blank control group and mimics-NC group(P<0.05),while the number of Hep G2 cells that spenetrated into the lower chamber in mi R-98 inhibitor group was significantly more than the blank control group and inhibitor-NC group(P<0.05).7.Western blot assay demonstrated that the expression level of Bcl-2 in mi R-98 mimics group was significantly lower than the blank control group and mimics-NC group(P<0.05).,while the expression level of Bcl-2 in mi R-98 inhibitor group was significantly higher than the blank control group and inhibitor-NC group(P<0.05) 48 h post-transfection.Conclusion:1.The expression level of mi R-98 was up-regulated by mi R-98 mimics effectively,while the expression level of mi R-98 was down-regulated by mi R-98 inhibitor effectively.2.Up-regulation of mi R-98 could inhibit cell proliferation of Hep G2 cells and increase cell apoptosis of Hep G2 cells,reduced the ability of invasion and migration.3.Down-regulation of mi R-98 could relatively promote cell proliferation of Hep G2 cells and decrease cell apoptosis of Hep G2 cells,enhanced the ability of invasion and migration.4.mi R-98 may promote the apoptosis of Hep G2 cells by down-regulating the expression of Bcl-2,...