Interferon therapy improves the irregular regeneration of hepatocytes in liver in patients with C-viral chronic hepatitis and liver cirrhosis

Clinical significance of CDT1 mRNA expression in chronic hepatitis C or liver cirrhosis

We have previously reported that chromatin licensing and DNA replication factor 1 (CDT1) is associated with the postoperative recurrence of hepatocellular carcinoma (HCC). Based on this fact, we verified whether CDT1 mRNA expression is also associated with HCC development from chronic hepatitis C (CHC) and liver cirrhosis (LC). There were 142 cases with CHC or LC who underwent liver biopsy. Detection of CDT1 mRNA in liver was performed by RT-qPCR using frozen liver biopsy tissues. We examined the association between the CDT1 mRNA expression and clinical conditions and long-term outcome. We then examined the association between serum cytokine/chemokine levels and CDT1 mRNA expression in 58 cases. The cumulative incidence rates of HCC development in cases with CDT1 mRNA in the low expression group showed significantly lower than those in the high expression group (p = 0.0391). A significant correlation was found between CDT1 mRNA expression and the extent of proliferation of atypical hepatocytes in hematoxylin and eosin-stained sections (p<0.0001). CDT1 mRNA expression has been associated with cytokines involved in tumorigenesis in experimental and human cancers. We found that cases with high CDT1 mRNA expression were at risk for developing HCC, even if they were CHC or LC.

The significance of CDT1 expression in non-cancerous and cancerous liver in cases with hepatocellular carcinoma

We previously reported that chromatin licensing and DNA replication factor 1 (CDT1) expression was associated with the extent of proliferation of atypical hepatocytes and the time to postoperative recurrence in cases of hepatocellular carcinoma (HCC). This study aimed to clarify the clinical significance or pathogenesis of CDT1 expression in both non-cancerous and cancerous liver in HCC cases, including previously published data. We investigated the association between the expression of CDT1 in non-cancerous or cancerous liver tissues and histologic findings or biochemical examination results in 62 cases. We also examined the dual localization between CDT1 and FbxW7, P57kip2, P53 and c-Myc by confocal laser scanning microscopy. CDT1 mRNA expression was significantly higher in cancerous liver than in non-cancerous liver (p<0.0001). Elevated CDT1 mRNA expression indicates a significantly degree of inflammatory cell infiltration within lobules, along with elevated serum transaminase levels, and hepatic spare decline. CDT1 mRNA was highly expressed in a group of poorly differentiated cancer cells. CDT1 co-localized with P57kip2, Fbwx7, P53 and c-Myc in the nucleus or cytoplasm of hepatocytes and cancer cells. We found that CDT1 mRNA expression could represent the degree of hepatic spare ability and the high carcinogenic state.

The proliferation of atypical hepatocytes and CDT1 expression in noncancerous tissue are associated with the postoperative recurrence of hepatocellular carcinoma

Recently, we reported that extent of proliferation of atypical hepatocytes (atypical hepatocytes) was most important histological risk factor for development of hepatocellular carcinoma (HCC) from chronic hepatitis C or liver cirrhosis. Here, we aimed to clarify whether the atypical hepatocytes in noncancerous sections is also involved in postoperative recurrence. Furthermore, we investigated significant genes involved in the atypical hepatocytes. Association between the extent of atypical hepatocytes in noncancerous tissue and postoperative recurrence was validated in 356 patients with HCC. Next, we identified putative signature genes involved in extent of atypical hepatocytes. First, atypical hepatocytes or hepatocytes other than the atypical hepatocyte in noncancerous sections of 4 HCC patients were selectively collected by laser capture microdissection (LCM). Second, the gene expression profiles of the selected hepatocyte populations were compared using Ion AmpliSeq Transcriptome Human Gene Expression Kit (Thermo Fisher SCIENTIFIC, Waltham, MA, USA) analysis. Finally, we validated the mRNA expression of the extracted genes in noncancerous frozen liver tissue from 62 patients with HCC by RT-qPCR to identify the signature genes involved in both the extent of atypical hepatocytes and postoperative recurrence. Furthermore, the extent of atypical hepatocytes and CDT1 expression in noncancerous sections from 8 patients with HCC were also validated by selectively collecting samples using LCM. The extent of atypical hepatocytes was associated with postoperative recurrence. Of the genes that showed significant differences in expression levels between two populations, the expression of the chromatin licensing and DNA replication factor 1 (CDT1) gene was most strongly associated with the extent of atypical hepatocytes and was also associated with postoperative recurrence. Furthermore, CDT1-positive cells that exhibited stronger expression resembled those morphologically considered to be atypical hepatocytes. CDT1 and Ki-67 were colocalized in the nuclei of both hepatocytes and cancer cells. The hepatocytes in noncancerous livers were not uniform in each hepatocyte population, suggesting that the accumulation of genetic abnormalities was variable. We found that the strong degree of atypical hepatocytes and high CDT1 mRNA expression represent a high carcinogenic state of the liver. Thus, we consider the evaluation of degree of these could support the personalized medicine.

Hepatocyte Turnover in Chronic HCV-Induced Liver Injury and Cirrhosis

Chronic hepatitis C virus (HCV) infection may eventually lead to progressive liver fibrosis and cirrhosis through a complex, multistep process involving hepatocyte death and regeneration. Despite common pathogenetic pathways present in all forms of liver cirrhosis irrespective of etiology, hepatocyte turnover and related molecular events in HCV-induced cirrhosis are increasingly being distinguished from even “similar” causes, such as hepatitis B virus- (HBV-) related cirrhosis. New insights in HCV-induced hepatocellular injury, differential gene expression, and regenerative pathways have recently revealed a different pattern of progression to irreversible parenchymal liver damage. A shift to the significant role of the host immune response rather than the direct effect of HCV on hepatocytes and the imbalance between antiapoptotic and proapoptotic signals have been investigated in several studies but need to be further elucidated. The present review aims to comprehensively summarize the current evidence on HCV-induced hepatocellular turnover with a view to outline the significant trends of ongoing research.

Histopathology of type C liver disease for determining hepatocellular carcinoma risk factors

AIM: To evaluate the histopathological findings of type C liver disease to determine risk factors for development of hepatocellular carcinoma (HCC).

METHODS: We studied 232 patients, who underwent liver biopsy for type C chronic liver disease between 1992 and 2009, with sustained virological response (SVR) after interferon therapy. The patients were divided into two groups according to the F stage 0 + 1 + 2 group (n = 182) and F3 + 4 group (n = 50). We prospectively observed and compared the incidence of HCC of the patients with SVR in the F0 + 1 + 2 and F3 + 4 groups. Then, the background factors and liver histopathological findings, including the degree of fibrosis, F stage, inflammation, necrosis, bile duct obstruction, fat deposition, and degree of irregular regeneration (IR) of hepatocytes, were correlated with the risk of developing HCC.

RESULTS: HCC developed in three of 182 (1.6%) patients in the F0 + 1 + 2 group, and four of 50 (8.0%) in the F3 + 4 group. The cumulative incidence of HCC in the former group was found to be significantly lower than in the F3 + 4 group (log rank test P = 0.0224). The presence of atypical hepatocytes among IR of hepatocytes in the F3 + 4 group resulted in a higher cumulative incidence of HCC, and was significantly correlated with risk of HCC development (RR = 20.748, 95%CI: 1.335-322.5, P = 0.0303).

CONCLUSION: Atypical hepatocytes among the histopathological findings of type C liver disease may be an important risk factor for HCC development along with progression of liver fibrosis.

Early interferon-based treatment after detection of persistent hepatitis C virus infection: a critical decision

Approximately 170 million people are infected with the hepatitis C virus (HCV) worldwide. Infection with this pathogen is persistent in more than 80% of cases, frequently developing severe forms of liver damage such as cirrhosis and hepatocellular carcinoma. No preventive vaccine is available against HCV, and current treatment based on the combination of pegylated interferon and ribavirin is effective in ∼55% of patients infected with genotype 1, the most prevalent genotype. This review analyzes several factors influencing the achievement of a sustained virological response, namely undetectable HCV RNA at 6 months after conclusion of therapy. Particularly, the relevant issue of age and duration of infection is discussed in detail. Indeed, the final decision for starting treatment should be a case-by-case point. However, the cost-benefit analysis seems to indicate that in patients who are motivated and without contraindications, starting the treatment as early as possible is probably the best choice for success.