OBJECTIVE:
MicroRNAs (
miRNAs) are small non-
coding RNAs that regulate
gene expression at the posttranscriptional level. Some
miRNAs, including
let-7a and miR-195, have been described as
tumor suppressors. However, the
roles of these
microRNAs in
breast cancer progression remain controversial. The aim of this study is to evaluate miR-195 and
let-7a expression as potential
biomarkers of invasive
breast cancer.
METHODS:
In the present study, 200 individuals were
separated into three groups (i) 72
women constituting the
control group who were selected according to rigorous and well-established criteria; (ii) 56
patients with benign
breast tumors; and (iii) 72
patients with malignant
breast cancers of different clinical stages. The miR-195 and
let-7a expression levels in
serum were evaluated by
real-time PCR. The results were assessed alone and in combination, and the
analysis included an estimation of
sensitivity and specificity in
ROC curves.
RESULTS:
Compared with the benign and
control groups, both
microRNAs were downregulated in the malignant
breast cancer patient group. Compared with the malignant group, the combination of both
biomarkers in the control and benign groups showed good
sensitivity and specificity in the
serum with AUCs of 0.75 and 0.72, respectively. The
biomarker combination for the
control group versus the malignant group exhibited a better
sensitivity and specificity than for the benign group versus the malignant group.
CONCLUSION:
These findings support the evidence that the
analysis of miR-195 and
let-7a can be used as a non-invasive
biomarker for
breast cancer detection.