The Expression Of MiR-494 In Serum And Tissues Of Breast Cancer Patients And Its Clinical Significance

Objective: To investigate the expression of mi RNA-494 in breast cancer tissue of patients and breast cancer cell lines and its relationship with the clinical stages,metastasis and prognosis of breast cancer.Methods: The expression of miR-494 was measured by quantitative real-time polymerase chain reaction(qRT-PCR)in 5 breast cancer cells(MDA-MB-231,MDA-MB-453,HCC-1937,MDA-MB-468,MCF-7)and 1 normal breast cell HBL-100.The expression of miR-494 was validated by qRT-PCR in breast cancer tissue and paraneoplastic tissue(n=54),and their correlation with clinical pathological parameters was analyzed.Results: The results of qRT-PCR indicated that the expression of miR-494 was downregulated in breast cancer cell lines compared with normal breast cells.The level of mi R-494 in all 5 breast cancer cell lines(MDA-MB-231,MDA-MB-453,HCC-1937,MDA-MB-468,MCF-7)were significantly downregulated compared with the normal breast cell(t = 212.9、37.73、27.53、10.61、19.46,P<0.05).In addition,the expression of miR-494 in breast cancer tissues were significantly downregulatedcompared with normal adjacent tissues(t=5.80,P<0.01).MiR-494 downregulation is notably correlated with clinical stage(χ2=17.41,P<0.05),tumor grade(χ2=5.33,P<0.05),C-erbB-2 positive or negative(χ2=9.83,P<0.05)and the percentage of Ki-67 positive cell(χ2=6.13,P<0.05).In addition,the expression of miR-494 in breast cancer tissues were significantly downregulatedcompared with normal adjacent tissues(t=5.80,P<0.01).MiR-494 downregulation is notably correlated with clinical stage(χ2=17.41,P<0.05),tumor grade(χ2=5.33,P<0.05),C-erbB-2 positive or negative(χ2=9.83,P<0.05)and the percentage of Ki-67 positive cell(χ2=6.13,P<0.05).Conclusion: The expression of mi R-494 was significantly downregulated in breast cancer tissues and breast cancer cell lines.MiR-494 downregulation was dramatically associated with the advanced clinical staging,metastasis and prognosis.MiR-494 may serve as a new biomarker to detection and prognosis estimates of breast cancer.