| Background:MicroRNAs(mi RNAs or mi Rs) are non-protein coding single-stranded small molecule RNAs, which have highly conservative sequence; they are endogenous and widely in eukaryotes. Mi RNAs are regulators of gene expression through inhibition of target m RNA translation or degradation of target m RNA to participate in development, metabolism, proliferation, differentiation, and oncogenesis, etc. Mi RNAs are closely related to the series of tumor development and progression, so the biological function of mi RNAs may have great significance to the diagnosis and treatment of breast cancer. Although breast cancer have abnormal expressions of mi RNAs, the roles of mi R-182 in the development of breast cancer research are rare.Objective:1. To investigate the expression and significance of mi R-182 in breast carcinoma cells and breast benign or malignant tissues.2. To investigate the effect of mi R-182 on breast cancer cell invasion, migration and proliferation potential.Method:1. On the foundation of cell cultures, applying Real time PCR to 2 normal breast cell lines, 9 breast carcinoma cell lines(including 5 low-grade malignant, 4 high-grade malignant) in detection of mi RNA-182;2. Applying Real time PCR to fresh breast tissues(tissue samples of 22 breast cancer and 11 benign breast diseases) in detection of mi RNA-182;3. Using tissue microarray platform and applying in situ hybridization detection mi RNA-182 in tissue samples of 79 human breast carcinoma cases, and 21carcinoma adjacent tissues cases;4. Human breast cancer MCF-7 cells were transfected with mi R-182 inhibitors by Lipofectamine. MCF-7 cells transfected with negative control(NC) were cultured as negative control. Cell proliferation ability was evaluated by MTS kit assay. Cell invasion potential and migrating ability was detected by transwell migration and invasion assay.Results:1. The levels of mi R-182 expression in 2 normal breast cell lines, 5 low-grade malignant breast carcinoma cell lines and 4 high-grade malignant breast carcinoma cell lines were decreasing. P-values were both <0.001 and statistically significant;2. In breast tissue specimens, the mean level of mi R-182 expression in 11 benign breast disease tissues were higher than that in 22 breast carcinoma tissues and there are significant differences(P<0.001);3. The positive rate of mi R-182 expression in breast carcinoma tissues(36.7%) were lower than those of carcinoma adjacent tissues(66.7%)(P<0.05);4. The level of mi R-182 expressions in breast carcinoma tissues were negatively correlated to the metastasis of lymph node(P=0.035). The study also found that the expression of mi R-182 in breast carcinoma tissues have nothing with the expression levels of ER, PR and HER-2, and the patient age, cancer sizes, histological grades, TNM grades(P>0.05);5. The survival rates and overall survival rates of 5 years without recurrence after surgery of mi R-182 negative expression were both lower than that of mi R-182 positive expression(P<0.05);6. MCF-7 cells showed growth strengthen in mi R-182 ASO transfectant compared with the control transfectant(P<0.05);7. Transfection of mi R-182 ASO led to a significant increase in cell invision and migration detected by transwell invasion and migration assay(both P<0.05).Conclusion:1. The levels of mi R-182 expression in human breast cancer is down-regulated,mir-182 is probably related to the occurrence of breast cancer;2. Mi R-182 negatively regulate the invasion and migration potential of breast cancer cells. |
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