Down-regulation of tissue microRNA-126 was associated with poor prognosis in patients with cutaneous melanoma

Background: MiR-126 is frequently downregulated in a variety of malignancies and acts as a potential tumor suppressor. It also played a tumor suppressor role in human melanoma through the direct or indirect repression of several key oncogenic molecules. Methods: qRT-PCR assay was performed to examine the expression of miR-126. Associations between miR-126 expression and various clinicopathological characteristics were analyzed using the χ2 test. Survival rate was determined with Kaplan-Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis. Results: Significant differences for miR-126 expression were shown between dysplastic nevi and primary cutaneous melanoma (P<0.01), between primary melanoma and metastatic cutaneous melanomas (P<0.01), and between primary cutaneous melanomas and metastatic cutaneous melanomas (P<0.001). The patients with low miR-126 expression showed shorter 5-year overall survival than those with high miR-126 expression (P=0.039; log-rank test). Multivariate regression analysis showed that the status of miR-126 expression was an independent prognostic factor overall survival (HR=3.782, 95% CI: 2.479-16.334, P=0.005). Conclusion: The status of miR-126 might be an independent prognostic factor for patients with cutaneous melanoma.