The Role And Mechanism Of Micro RNA-204 In The Regulation Of PI3K/AKT Pathway On The Proliferation And Metastasis Of Breast Cancer

The incidence of breast cancer in China ranks first among female malignant tumors and has become the number one killer of women,while the incidence of breast cancer in China is increasing year by year and showing a younger trend.Although the development of early breast cancer screening and the improvement of comprehensive treatment level improve the therapeutic effect,there are still 30% of breast cancer patients with advanced recurrence and metastasis,which seriously threaten the health and safety of women.With the continuous in-depth study of breast cancer and other tumors,people gradually realize the role of "micro RNA" in tumorigenesis.Various kinds of micro RNAs are the basis of genetic regulation of tumour genes,which affect the biological behavior of differentiation,metabolism and invasion of tumour cells in varying degrees.A large number of studies also show that there are pathological data and predictions in many tumors,including breast cancer and micro RNA.Later correlation.Among them,the relationship between mi R-204 and breast cancer is the focus of this study.Understanding the role and mechanism of micro RNAs in the occurrence and progression of breast cancer is helpful to effectively prevent and control the treatment and prognosis of breast cancer.To clarify the expression of mi R-204 in breast cancer patients is helpful to find markers for early diagnosis and molecular targets for precise treatment of breast cancer,and has extremely important clinical significance for improving the level of comprehensive treatment of breast cancer.Part I The relationship between the expression of mi R-204 and clinicopathological data of breast cancerObjectiveTo clarify the correlation between the expression of mi R-204 and clinicopathological data of breast cancer patients.MethodsRT-qPCR was used to detect the expression of mi R-204 in breast cancer pathological tissues,and the correlation between mi R-204 and clinical data was analyzed with pathological data.Result1.The expression of mi R-204 in normal breast tissues and cancerous tissues was significantly lower than that in normal breast tissues(P<0.05).2.There was no significant correlation between the level of mi R-204 and age,tumor diameter,ER,RP and HER2 expression intensity.The level of mi R-204 decreased significantly with the increase of histopathological grade and clinical stage,and the level of mi R-204 in lymphatic metastasis was significantly lower than that in non-lymphatic metastasis transferred tissues(P<0.05).Part II Effects of Micro RNA-204 on Proliferation,Invasion and Apoptosis of Breast Cancer CellsObjectiveTo investigate the effects of mi R-204 on proliferation,invasion and apoptosis of breast cancer MCF-7 cell line.Methodsmi R-204 was transfected into MCF-7 cells by liposome.The proliferation of MCF-7 cells was detected by MTT assay.Apoptosis was detected by Hoechst 33342 staining.Cell cycle was detected by flow cytometry and cell invasion and migration were detected by Transwell method.Result1.External transfection of mi R-204 mimics to MCF7 cells significantly increased the level of mi R-204,and overexpression of mi R-204 significantly inhibited the viability of MCF7 cells compared with the mi R-NC group.2.The results of Hoechst 33342 showed that the number of apoptotic cells in the mi R-204 mimics group was significantly higher than that in the mi R-NC group.Annexin V/PI test also showed that the apoptotic rate in the mi R-204 MICs group was significantly higher than that in the mi R-NC group.3.Overexpression of mi R-204 can induce G2/M cell cycle arrest in breast cancer MCF7 cells4.Compared with the mi R-NC group,the number of MCF7 cells transfected with mi R-204 Minics decreased significantly.5.Compared with the mi R-NC group,the invasive ability of MCF7 cells transfected with mi R-204 Minics was significantly reduced.Part III Effects of Micro RNA-204 Overexpression on PI3K/AKT Signaling Pathway in Breast CancerObjectiveTo investigate the effect of mi R-204 on the biological behavior of MCF-7 cells and the mechanism of the occurrence and development of breast cancer.MethodsThe expression of PTEN in breast cancer cells and human breast cells was compared.Using Target Scan target gene prediction software,PTEN was screened as the regulatory target gene of mi R-204,which was validated by test the influence of mir-204 on PTEN expression.The effect of mi R-204 on the expression of PTEN in MCF-7 cells was analyzed;and the activity changes of PI3K/AKT signaling pathway related proteins were detected.Result1.The expression level of PTEN in MCF-7 cells was lower than that in HS 841.T cells.2.The Target Scan target gene prediction report showed that there were complementary fragments in mi R-204 and PTEN sequences,suggesting that PTEN was a potential downstream target gene regulated by mi R-204.3.Overexpression of mi R-204 in MCF-7 cells can improve the expression of PTEN m RNA and protein.4.Over expression of mi R-204 in MCF-7 cells can significantly inhibit the PI3K/AKT pathway related protein activity.Conclusion1.The expression of mi R-204 was lower in breast cancer tissues and correlated with clinical data of breast cancer.2.Overexpression of mi R-204 can affect the biological behavior of breast cancer MCF-7 cells,such as proliferation,apoptosis,cell cycle and invasion.3.Mi R-204 targeting PTEN inhibits PI3K/AKT signaling pathway and inhibits the occurrence and development of breast cancer.