Relationship Between Serum microRNA155 and Telomerase Expression in Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Activation of telomerase reverse transcriptase (hTERT) has a role in liver carcinogenesis where telomerase is normally suppressed in most human somatic tissues after birth. In the current study we aimed to detect the significance of hTERT mRNA in early detection of hepatocellular carcinoma (HCC) and to determine the relationship between serum microRNA155 and telomerase expression.

METHODS: Serum and liver tissue samples were collected from 40 patients (17 samples from patients with liver cirrhosis and 23 samples from patients with HCC) and 12 blood samples from healthy subjects were collected. Serum miRNA155 levels and blood and tissue hTERT mRNA were detected by real-time quantitative reverse-transcriptase PCR (RT-qPCR) among liver cirrhosis and HCC patients. Moreover, miR-155, blood and tissue hTERT levels were analyzed in relation to clinical and pathological features.

RESULTS: Calculated expression of miRNA155 revealed that relative quantity (RQ) miR 155 was overexpressed in sera of HCC patients when compared to patients with liver cirrhosis and controls (p <0.0001). The median values of serum telomerase were significantly increased among HCC patients than in patients with liver cirrhosis and controls (p = 0.04). Moreover, tissue expression of telomerase was significantly higher in malignant tissue more than adjacent nonmalignant tissue among HCC patients (p = 0.02). It was also found that tissue expression of telomerase was significantly decreased in tissue of liver cirrhosis patients (p = 0.03). Interestingly, we found that blood telomerase was directly correlated with serum miRNA155 (p = 0.003).

CONCLUSIONS: Both mir 155 and telomerase may have a role in development of HCC and mir 155 could regulate telomerase expression during liver carcinogenesis.