Hepatitis B Virus Covalently Closed Circular DNA Predicts Postoperative Liver Cancer Metastasis Independent of Virological Suppression
Chao-Wei Hsu 1 2 , Yu-De Chu 1 , Ming-Wei Lai 1 3 , Chih-Lang Lin 4 , Kung-Hao Liang 5 , Yang-Hsiang Lin 1 , Chau-Ting Yeh 1 6
Affiliations
Affiliations
1
Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
2
Department of Hepatogastroenterology, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
3
Division of Pediatric Gastroenterology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
4
Liver Research Unit, Chang Gung Memorial Hospital, Keelung 204, Taiwan.
5
Medical Research Department, Taipei Veterans General Hospital, Taipei 112, Taiwan.
6
Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan.
PMID: 33572617 DOI: 10.3390/cancers13030538
Abstract
New antiviral therapies against hepatitis B virus (HBV) focus on the elimination of covalently closed circular DNA (cccDNA). However, traditional cccDNA-specific quantitative PCR (qPCR) has a narrow effective range, hindering a reliable comparison between the levels of biopsy-derived cccDNAs. Collaterally, the prognostic role of cccDNA in HBV-related hepatocellular carcinoma (HCC) cannot be clearly defined. Here, we developed a peptide nucleic acid (PNA)-clamping qPCR method to provide a wider range of specific cccDNA quantification (up to 5 logs of effective range). Extrachromosomal DNA was extracted from para-neoplastic tissues for cccDNA quantification. In total, 350 HBV-related HCC patients were included for an outcome analysis. Without differential pre-dilution, cccDNA levels in para-neoplastic liver tissues were determined, ranging from < 2 × 103 to 123.0 × 106 copies/gram. The multivariate linear regression analysis showed that cccDNA was independently correlated with the HBV e antigen (p < 0.001) and serum HBV-DNA levels (p = 0.012). The Cox proportional hazard model analysis showed that cccDNA independently predicted overall survival (p = 0.003) and extrahepatic metastasis-free survival (p = 0.001). In virologically suppressed HCC patients, cccDNA still effectively predicted intrahepatic recurrence-free (p = 0.003) and extrahepatic metastasis-free (p = 0.009) survivals. In conclusion, cccDNA independently predicted postoperative extrahepatic metastasis-free survival.
Keywords: covalently closed circular DNA; hepatitis B virus; hepatocellular carcinoma; metastasis; peptide nucleic acid clamping.
Grant support
107-2314-B-182-004-MY3; 107-2314-B-182A-109/Ministry of Science and Technology, Taiwan
CRRPG3F0053; CMRPG3H1441/Chang Gung Memorial Hospital, Linkou