Alteration of telomeric repeat length in hepatocellular carcinoma is independent of telomerase activity

Association between telomere length and hepatic fibrosis in non-alcoholic fatty liver disease

Telomere length has been linked to the prevalence and progression of metabolic disease. However, clinical implications of telomere length in biopsy-proven non-alcoholic fatty liver disease (NAFLD) patients remain unclear. Therefore, this study aimed to investigate the association of telomere length with the histological severity of NAFLD. The cross-sectional data derived from the prospectively enrolled Boramae NAFLD registry (n = 91) were analyzed. The liver tissues and clinical information were obtained from both NAFLD patients and non-NAFLD subjects. Binary logistic regression was performed to identify the independent association between telomere length and the histological severity of NAFLD. A total of 83 subjects with or without biopsy-proven NAFLD were included for analysis: non-NAFLD in 23 (27.7%), non-alcoholic fatty liver in 15 (18.1%), and non-alcoholic steatohepatitis (NASH) in 45 (54.2%). Telomere length measured from liver tissues showed a strong negative correlation (p < 0.001) with age, regardless of NAFLD status. Therefore, telomere length was corrected for age. Age-adjusted telomere length than decreased gradually with an increasing severity of fibrosis in patients with NAFLD (p < 0.028). In multivariate analysis, age-adjusted telomere length (odds ratio [OR] 0.59; 95% CI 0.37–0.92; p = 0.019) and high-density lipoprotein cholesterol (OR 0.94; 95% CI 0.80–0.99; p = 0.039) were independently associated with significant fibrosis. The age-adjusted telomere length tends to decrease along with the fibrosis stage of NAFLD. In particular, among the histological components of NAFLD, fibrosis severity seems to be related to telomere length in the liver.

Telomerase activity, telomere length and human telomerase reverse transcriptase expression in hepatocellular carcinoma is independent of hepatitis virus status

BACKGROUND

Telomerase expression and the maintenance of a critical telomere length (TL) in cancer initiation indicates that telomere shortening and telomerase expression initiates cancer by induction of chromosomal instability.

METHODS

Telomerase activity, TL and human telomerase reverse transcriptase (hTERT) expression were investigated in 58 hepatocellular carcinoma (HCC) and 17 chronic hepatitis patients by the telomerase repeat amplification protocol, Southern blotting and reverse transcriptase-polymerase chain reaction.

RESULTS

Telomerase was positive in 76% of HCC and 11.8% of chronic hepatitis patients (P<0.0001). The mean telomere length (MTL) in HCC was significantly shorter compared with chronic hepatitis (P<0.0001). The MTL was not significantly different in HCC patients with and without cirrhosis (P=0.77). In hepatitis B virus, hepatitis C virus and non-B non-C-related HCC groups, no differences were found in telomerase activity and MTL (P=0.77). hTERT, a regulator of telomerase, was, however, positive in 81% of HCCs. The correlation between telomerase activity and hTERT mRNA expression was statistically significant (P<0.0001). The MTL in telomerase-positive HCC cases was significantly shorter than the MTL in telomerase-negative cases (P<0.0001).

CONCLUSION

The majority of HCCs exhibited telomerase activity that correlated well with hTERT expression. MTL in HCC was significantly shorter than chronic hepatitis. It was also found that shorter telomeres are present in telomerase-positive HCC cases. However, no correlation was found between telomerase activity and TL with respect to the viral status in HCC.