Kazuhiro Hirohashi

p16 Promoter Hypermethylation in Human Hepatocellular Carcinoma with or without Hepatitis Virus Infection

Background: Epigenetic alteration through methylation is one of the most important steps in carcinogenesis. However, the relation between hepatitis virus infection and epigenetic alterations is poorly understood. Methods: Sixteen patients without hepatitis B virus (HBV) and hepatitis C virus (HCV) and 35 patients with HBV or HCV who underwent liver resection for hepatocellular carcinoma (HCC) were studied. Mutation of p53 was detected by direct sequencing. Methylation status of p16 was evaluated in tumor and noncancerous liver tissues by methylation-specific polymerase chain reaction. Results: In HCC without HBV and HCV, p53 mutations were detected in 5 (31%) of 16 HCCs. Methylation of p16 promoter was detected in 2 (25%) of 8 moderately differentiated HCCs, 6 (75%) of 8 poorly differentiated HCCs, and none of 16 noncancerous tissue specimens. In HCC with HBV or HCV, p53 mutations were detected in 8 (23%) of 35 HCCs. Methylation of p16 promoter was detected in 2 (100%) of 2 well-differentiated HCCs, 13 (76%) of 17 moderately differentiated HCCs, 12 (75%) of 16 poorly differentiated HCCs, and 9 (26%) of 35 noncancerous liver tissue specimens. Conclusions: Our results suggest that hepatitis viruses might induce methylation of p16 promoter in liver with chronic inflammation, before appearance of HCC.

Cytokeratin-19 fragments in serum (CYFRA 21-1) as a marker in primary liver cancer

Using an electrochemiluminescence immunoassay, CYFRA 21-1 concentrations were measured in sera from 187 patients with primary liver cancer (164 with hepatocellular carcinoma (HCC) and 23 with intrahepatic cholangiocarcinoma (ICC)) and 87 patients with benign liver diseases. Concentrations of CYFRA 21-1 were significantly higher in patients with ICC (5.0; interquartile range 3.1–10.7u2009ngu2009ml−1) than in those with benign liver disease (1.4; 1.0–1.9; Mann–Whitney U-test, P<0.0001) or HCC (1.7; 1.1–2.7; Mann–Whitney U-test, P<0.0001). Using cutoff values selected for 95% specificity in the benign group (3.0u2009ngu2009ml−1), CYFRA 21-1 showed higher sensitivity for ICC (87.0%) than three commonly used markers including α-fetoprotein (17.4%), carcinoembryonic antigen (34.8%), and carbohydrate antigen 19-9 (60.9%). Serum CYFRA 21-1 increased in ICC from stages I/II to IV (Kruskal–Wallis test, P=0.0102). CYFRA 21-1 concentration increased with extent of local invasion, but not nodal status. Serum CYFRA 21-1 represents a useful diagnostic test for ICC that offers high sensitivity. CYFRA 21-1 reflected differences in tumour burden, suggesting applicability to staging and follow-up.

Correlation between clinical characteristics and mitochondrial D-loop DNA mutations in hepatocellular carcinoma.

BackgroundMitochondrial DNA (mtDNA) mutations are found in many kinds of human cancer. The aim of this study was to evaluate the relationship between mtDNA mutations in the liver and human hepatocarcinogenesis.MethodsDirect sequencing of mtDNA was done in 54 hepatocellular carcinomas (HCCs) and 47 surrounding liver tissue samples, obtained from 54 patients with HCC, and in 5 liver samples without inflammation, obtained from 5 patients with metastatic liver tumors. We also examined p53 mutations in the 54 HCCs to examine the correlation between nuclear DNA mutations and mtDNA mutations.ResultsMutations of mtDNA in the D-loop region were found in both HCC and noncancerous liver tissue. In normal liver without chronic inflammation, no mtDNA mutation was detected. In every case, the number of mtDNA mutations in HCC correlated with that in noncancerous liver tissue. Twelve of 52 mutation sites in the D-loop region of mtDNA were specific for HCC. The mean number of mtDNA mutations was 1.7 in well-differentiated HCC, as compared with 4.5 in moderately differentiated HCC and 4.6 in poorly differentiated HCC. The frequency of mtDNA mutations was thus higher in less differentiated HCC. We detected p53 mutations in 15 (28%) of 54 HCCs. The mean number of mtDNA mutations was 5.3 in HCC with p53 mutations and 3.8 in HCC with wild-type p53 (P = 0.024).ConclusionsA higher frequency of mtDNA mutations was found in less differentiated HCCs, and it is also possible that mtDNA mutations are related to nuclear DNA mutations in HCC. The accumulation of mtDNA mutations is a useful predictor of hepatocarcinogenesis.

Correlation Between Preoperative Serum Concentration of Type IV Collagen 7s Domain and Hepatic Failure Following Resection of Hepatocellular Carcinoma

Objective:To determine the predictive value of the preoperative serum concentration of type IV collagen 7s domain (7s collagen) for postoperative hepatic failure in patients undergoing liver resection for hepatocellular carcinoma. Summary Background Data:Clear and reliable criteria for predicting hepatic failure after liver resection are needed. The serum 7s collagen concentration correlates with the histologic degree of active hepatitis and hepatic fibrosis and may predict the regenerative potential of the liver. Methods:Potential risk factors for postoperative hepatic failure, including the serum 7s collagen concentration, were evaluated in 251 patients who underwent liver resection for hepatocellular carcinoma. Prognostic significance was determined by univariate and multivariate analyses. Results:Hepatic failure developed postoperatively in 25 patients, 4 of whom died. The serum 7s collagen concentration correlated with the histologic degree of hepatitis activity and hepatic fibrosis. The serum 7s collagen concentration was a risk factor for postoperative hepatic failure by univariate analysis and was the only risk factor on multivariate analysis. No patient with a serum 7s collagen concentration <12 ng/mL died of postoperative hepatic failure, and all 4 patients who died had a serum 7s collagen concentration ≥12 ng/mL. Conclusions:The preoperative serum 7s collagen concentration correlated independently with hepatic failure following liver resection for hepatocellular carcinoma. Patients whose serum 7s collagen is ≥12 ng/mL are poor candidates for hepatic resection.

Multicentric occurrence of hepatocellular carcinoma in patients with a somatic mutation of mitochondorial DNA and hepatitis C virus

The relationship between the multicentric occurrence of hepatocellular carcinoma (HCC) and the frequency of mutation of mitochondrial DNA (mtDNA) in the noncancerous hepatic tissue in patients infected with hepatitis C virus was investigated. Of the 48 patients, multicentric occurrence of HCC was found in ten of 33 patients with three or more mutations in the mtDNA, whereas no patients had multicentric HCCs in 15 patients with two or fewer mutations in the mtDNA (P=0.0201). A high rate of mtDNA mutation in noncancerous hepatic tissue may be related to multicentric hepatocarcinogenesis and the hypercarcinogenic state in such patients.

Serum concentration of type IV collagen 7S domain as a marker for increased risk of recurrence after liver resection for hepatocellular carcinoma.

Background/Aims: Serum concentration of type IV collagen 7S domain (7S collagen) is a marker of hepatic fibrosis. We investigated the usefulness of measuring the serum 7S collagen concentration as a risk factor for recurrence after liver resection for hepatocellular carcinoma (HCC). Methods: The serum 7S collagen concentration was measured before liver resection for HCC in 219 patients. Group 1 included 102 patients with a high serum concentration of 7S collagen (≧8.0 ng/ml), and group 2 consisted of 117 patients with a low serum concentration of 7S collagen (<8.0 ng/ml). Clinicopathologic findings and outcome after surgery were compared between groups. Results: The results of liver function tests were better in group 2 than in group 1. The percentage of patients with cirrhosis or who underwent minor resection was higher in group 1 than in group 2. The percentage of patients with moderately or poorly differentiated HCC or portal invasion was higher in group 2 than in group 1. Univariate and multivariate analyses identified that a high serum concentration of 7S collagen (≧8.0 ng/ml) was an independent risk factor for recurrence. Conclusion: Measuring the serum 7S collagen concentration is useful to estimate the risk of recurrence after resection of HCC.