MiR-126 in Hepatocellular Carcinoma and Cholangiocellular Carcinoma: A Reappraisal with an in situ Detection of miR-126.

OBJECTIVE

Hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCA) represent the most common malignant tumors of the liver. MicroRNAs (miRNAs) are small non-coding RNAs that play a role in regulating gene expression post-transcriptionally. The altered expression of miRNAs has been observed in many malignancies, including liver cancer. However, the expression level of miR-126 in HCC and CCA and its role in carcinogenesis show debatable data currently.

METHODS

In this study, we investigate the expression level, localization, and biological significance of miRNA-126 in HCC and CCA.

RESULTS

Our in situ hybridization analysis showed a significant reduction in miR-126 levels in HCC and CCA tissues relative to their corresponding healthy tissues. Conversely, miR-126 was expressed in the normal hepatocytes, blood vessels, and sinusoidal cells. Also, we detected a low expression level of miR-126 in HCC and CCA cell lines. The overexpression of miR-126 in HepG2 and HuCCT1 using miRNA mimics significantly inhibited cell proliferation, growth, and migration.

CONCLUSION

This study further suggests that miR-126 plays a critical role in hepatic carcinogenesis. In our opinion, miR-126 warrants further investigations because this marker may have both diagnostic and prognostic implications in hepatocarcinogenesis.