Objective To investigate the expression levels of miR-494 in
breast cancer tissues and
cell lines,and its correlations with the clinical stages,
metastasis and
prognosis of
breast cancer.
Methods The expression levels of miR--494 in 5
breast cancer cell lines,including MDA-MB-231,MDA-MB-453,HCC-1937,MDA-MB-468 and MCF-7,and normal
breast cell line HBL-100,were detected by
quantitative real-time polymerase chain reaction (qRT-
PCR).The
breast cancer tissues and normal adjacent
tissues from 54
patients with
breast cancer were collected,and their expression levels of miR-494 were determined by qRT-
PCR.Then,the correlations of miR-494 levels with clinical stages,
metastasis and
prognosis of
breast cancer were analyzed.Results The expression levels of miR-494 in MDA-MB-231,MDA-MB-453,HCC-1937,MDA-MB-468 and
MCF-7 cells were significantly lower than that in HBL-100
cells (t =212.9,37.73,27.53,10.61 and 19.46,respectively,and all P <0.05).The expression levels of miR-494 in
breast cancer tissues were also significantly lower than that in normal adjacent
tissues (t =5.80,P < 0.01).Moreover,the expression of miR-494 was significantly related to the clinical stage (x2 =17.41,P <0.05),
tumor grade (x2 =5.33,P <0.05),C-erbB-2 expression (x2 =9.83,P < 0.05) and the percentage of Ki-67 positive
cells ((2 =6.13,P < 0.05) of
breast cancer.Conclusion The expression levels of miR-494 are significantly dowrregulated in
breast cancer tissues and
cell lines,and related to the clinical stage,
metastasis and
prognosis of
breast cancer,indicating that miR-494 may serve as a new
biomarker for the
diagnosis and
prognosis of
breast cancer.