Correlation between copy number of mitochondrial DNA and clinico-pathologic parameters of hepatocellular carcinoma

Aims In the current study, we investigated possible correlations of the mtDNA copy number in hepatocellular carcinoma (HCC) with the pathological findings and prognosis. Methods We studied 31 HCC specimens using quantitative real-time polymerase chain reaction analysis, and the correlation between the mtDNA copy number and the clinicopathologic parameters and mutations in the D-loop region of the mitochondrial genome. Results The mtDNA copy number was reduced in HCCs compared with the corresponding non-cancerous liver tissues (p=0.002), and significantly correlated with tumour size (p=0.014) and cirrhosis (p=0.048). Patients with a low mtDNA copy number tended to show shorter 5-year survival rates than patients with a high mtDNA copy number when assessed by Kaplan–Meier curves, but not a significant (overall survival rate, 63 vs 83%; p=0.19). The copy number of HCC with mtDNA D-loop mutation or deletion was lower, but not significantly so (p=0.656, p=0.590, respectively). Conclusions Our results indicated that a reduced copy number of mtDNA is correlated with HCC and associated with malignant potential.