Reduction of telomeric repeats as a possible predictor for development of hepatocellular carcinoma: convenient evaluation by slot-blot analysis

Metabolic dysfunction and cancer in HCV: Shared pathways and mutual interactions

HCV hijacks many host metabolic processes in an effort to aid viral replication. The resulting hepatic metabolic dysfunction underpins many of the hepatic and extrahepatic manifestations of chronic hepatitis C (CHC). However, the natural history of CHC is also substantially influenced by the host metabolic status: obesity, insulin resistance and hepatic steatosis are major determinants of CHC progression toward hepatocellular carcinoma (HCC). Direct-acting antivirals (DAAs) have transformed the treatment and natural history of CHC. While DAA therapy effectively eradicates the virus, the long-lasting overlapping metabolic disease can persist, especially in the presence of obesity, increasing the risk of liver disease progression. This review covers the mechanisms by which HCV tunes hepatic and systemic metabolism, highlighting how systemic metabolic disturbance, lipotoxicity and chronic inflammation favour disease progression and a precancerous niche. We also highlight the therapeutic implications of sustained metabolic dysfunction following sustained virologic response as well as considerations for patients who develop HCC on the background of metabolic dysfunction.

Role of Caspase-1 in the Pathogenesis of Inflammatory-Associated Chronic Noncommunicable Diseases

Caspase-1 is the first and extensively studied inflammatory caspase that is activated through inflammasome assembly. Inflammasome is a cytosolic formation of multiprotein complex that aimed to start inflammatory response against infections or cellular damages. The process leads to an auto-activation of caspase-1 and consequent maturation of caspase-1 target molecules such as interleukin (IL)-1β and IL-18. Recently, the role of caspase-1 and inflammasome in inflammatory-induced noncommunicable diseases (NCDs) like obesity, diabetes mellitus (DM), cardiovascular diseases (CVDs), cancers and chronic respiratory diseases have widely studied. However, their reports are distinct and even they have reported contrasting role of caspase-1 in the development and progression of NCDs. A few studies have reported that caspase-1/inflammasome assembley has a protective role in the initiation and progression of these diseases through the activation of the noncanonical caspase-1 target substrates like gasdermin-D and regulation of immune cells. Conversely, others have revealed that caspase-1 has a direct/indirect effect in the development and progression of several NCDs. Therefore, in this review, we systematically summarized the role of caspase-1 in the development and progression of NCDs, especially in obesity, DM, CVDs and cancers.

A Review of Hepatocellular Carcinoma in Elderly Patients Focused on Management and Outcomes

Recent studies report a significant age-specific increase in hepatocellular carcinoma (HCC) development among persons over 75 years old. Therefore, there is an urgent need to determine the optimal treatment strategy in elderly patients with HCC. This systemic review examines the clinical characteristics, efficacy, and safety of first-line treatment modalities. The literature was searched regarding epidemiology and clinical outcomes in elderly patients (age ≥75 years) undergoing first-line treatment for HCC. Causative or comorbid conditions of HCC in elderly patients differed from those in younger patients. Radiofrequency ablation may be effective and safe in early stages. Surgical resection may also be feasible in the early stages for selected patients. Transarterial chemoembolization may be safe and effective for intermediate HCC, and sorafenib may be feasible in elderly patients with advanced HCC. Prospective randomized trials are needed to establish the treatment strategy for elderly patients with HCC.

Associations between polymorphisms of the ACYP2 gene and Liver cancer risk: A case-control study and meta-analysis

Background

ACYP2 gene may be involved in the process of telomere shortening which may be involved in the liver cancer. So, this research was to examine whether the ACYP2 gene polymorphism has impact on the risk of liver cancer in Chinese population.

Methods

Two hundred and fifty cirrhosis patients and 248 liver cancer patients were selected. Unconditional logistic regression was to calculate the odds ratio (OR) and 95% confidence intervals (CIs). Analyze the relationship between ACYP2 gene polymorphism and tumor using meta‐analysis. Analyze the expression of ACYP2 gene in liver cancer and its influence on the prognosis of liver cancer by databases (Ualcan, GTEX and Kaplan–Meier plotter).

Results

In the allele model, ACYP2 rs843720 was protection against the occurrence of cirrhosis developed into liver cancer (OR = 0.76, 95% CI: 0.58–0.99, p = 0.04). Rs1682111 and rs843720 play a protective role in the additive model (rs1682111: OR = 0.69, 95% CI: 0.52–0.93, p = 0.01; rs843720: OR = 0.73, 95% CI: 0.54–0.98, p = 0.04).While rs843645 G allele increased the risk of cirrhosis developed into liver cancer under the additive model (OR = 1.42, 95% CI: 1.02–2.00, p = 0.04).The haplotype analysis detected that “ATATCGCC” decreased the risk of cirrhosis developed into liver cancer (OR = 0.69, 95% CI: 0.51–0.92, 95% CI: p = 0.013); however, “TGAGCGTC” increased the risk of cirrhosis developed into liver cancer (OR = 1.48, 95% CI: 1.04–2.10, p = 0.027). Meta‐analysis shown that ACYP2 rs1682111 was associated with the risk of cancer (OR = 0.90, 95% CI: 0.78–1.05, p = 0.02). ACYP2 gene high expression was found to be associated with better OS for all liver patients.

Conclusion

Based on this research, we surmised that ACYP2 gene may be involved in the occurrence of liver cancer in Chinese populations.

Expression signature of lysosomal-associated transmembrane protein 4B in hepatitis C virus-induced hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is a lethal disease worldwide and therefore the establishment of novel diagnostic biomarkers is imperative. In this study, it was hypothesized that an abnormal expression of the lysosomal-associated protein transmembrane 4 beta ( LAPTM4B) gene is crucial in the pathogenesis of hepatitis C virus-mediated hepatocellular carcinoma; hence we investigated the expression profile of LAPTM4B in hepatitis C virus-induced hepatocellular carcinoma.

METHODS

A group of 189 consecutive patients (hepatitis C virus-related hepatocellular carcinoma as tumor cases; n=93, hepatitis C virus-related cirrhotics as disease controls; n=96) opting for living donor liver transplantation as a therapeutic surgical regimen were recruited with informed consent. Additionally, paired adjacent non-tumorous tissues (n=93) obtained from cases were also included. Serum LAPTM4B protein concentrations were assessed by third-generation enzyme-linked immunosorbent assay and LAPTM4B mRNA, and protein expressions at tissue level were determined by quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry techniques, respectively.

RESULTS

LAPTM4B protein concentrations in sera of patients were higher ( p<0.001) in tumor cases (1.25±0.25 ng/ml) compared to disease controls (0.53±0.28 ng/ml). Our study also depicts positive clinicopathological correlations between alpha-fetoprotein titers (b=0.65; p<0.001), quantitative hepatitis C virus RNA copies (b=0.33; p<0.001), and LAPTM4B protein concentrations, all in sera of patients. In addition, qRT-PCR and immunohistochemistry analyses revealed a significantly higher ( p<0.05) tissue LAPTM4B mRNA and protein expression, respectively, in tumor cases rather than in non-tumorous tissues and disease controls.

CONCLUSIONS

Together, our results illustrate the LAPTM4B gene as a diagnostic biomarker in patients with hepatocellular carcinoma having documented evidence of chronic hepatitis C virus infection.

Inflammasomes in Inflammation-Induced Cancer

The inflammasome is an important multiprotein complex that functions during inflammatory immune responses. The activation of inflammasome will lead to the autoactivation of caspase-1 and subsequent cleavage of proIL-1β and proIL-18, which are key sources of inflammatory manifestations. Recently, the roles of inflammasomes in cancers have been extensively explored, especially in inflammation-induced cancers. In different and specific contexts, inflammasomes exhibit distinct and even contrasting effects in cancer development. In some cases, inflammasomes initiate carcinogenesis through the extrinsic pathway and maintain the malignant cancer microenvironment through the intrinsic pathway. On the contrary, inflammasomes also exert anticancer effects by specialized programmed cell death called pyroptosis and immune regulatory functions. The phases and compartments in which inflammasomes are activated strongly influence the final immune effects. We systemically summarize the functions of inflammasomes in inflammation-induced cancers, especially in gastrointestinal and skin cancers. Besides, information about the current therapeutic use of inflammasome-related products and potential future developing directions are also introduced.

Hepatocellular carcinoma in elderly patients: challenges and solutions

Hepatocellular carcinoma (HCC) is the second most common cause of death by cancer in the world. Due to the delayed HCC development in hepatitis C carriers and nonalcoholic fatty liver disease, the incidence of HCC in the elderly is increasing and is becoming a global health issue. Elderly patients with HCC should be assessed through proper oncologic approach, namely, screening tools for frailty (Geriatric-8 or Vulnerable Elders Survey-13) and comprehensive geriatric assessment. This review of the literature supports the same treatment options for elderly patients as for younger patients, in elderly patients selected as fit following proper oncogeriatric assessment. Unfit patients should be managed through a multidisciplinary team involving both oncological and geriatrician professionals. Specific studies and recommendations for HCC in the elderly should be encouraged.

Clinical characteristics and survival outcomes of super-elderly hepatocellular carcinoma patients not indicated for surgical resection

AIM

Considering the dramatic increase in average life expectancy during the 20th century throughout the world, the management of elderly patients with cancer has become a global issue. We herein investigated the clinical characteristics and outcomes of super-elderly hepatocellular carcinoma (HCC) patients over 80 years old not indicated for surgical resection.

METHODS

We retrospectively evaluated 206 newly diagnosed HCC patients. The patients were divided into two groups according to their age at inclusion; a super-elderly group (n = 37, ≥80 years) and a younger group (n = 169, <80 years). We compared the clinical characteristics, overall survival (OS) and disease-specific survival (DSS) rates among the two groups. Both univariate and multivariate analyses were performed to identify the factors associated with the OS and DSS.

RESULTS

The proportion of women was higher in the super-elderly group than in the younger group (P = 0.017). There were no significant differences in the OS (P = 0.171) or DSS (P = 0.176) between the two groups. The multivariate analysis revealed that only the Cancer Liver Italian Program score (hazard ratio [HR], 2.972; P < 0.0001; HR, 3.694; P < 0.0001) was independently associated with the OS and DSS. Age was not found to be associated with the OS or DSS according to either the univariate or multivariate analysis.

CONCLUSION

There were no significant differences in the OS and DSS rates among the super-elderly HCC patients and younger HCC patients not indicated for surgical resection. An advanced age itself does not restrict the therapeutic approach, even in super-elderly HCC patients not indicated for surgical resection.

Clinical features and prognosis of elderly patients with hepatocellular carcinoma not indicated for surgical resection

Hepatocellular carcinoma (HCC) is a major health problem worldwide. The average life expectancy during the 20th century has increased in many parts of the world, and therefore the opportunities to examine elderly HCC patients have significantly increased worldwide. Many elderly patients develop HCC with intermediate to advanced stages of disease at the initial diagnosis, and have more comorbidities and compromised liver regeneration compared with younger patients. These circumstances show that elderly patients with HCC are poorer candidates for surgical resection or transplantation. The aim of the present review was to focus on the clinical features and prognosis of elderly HCC patients not indicated for surgical resection including multimodal treatment. Although the chronological age of 60 or 65 years as the definition of an elderly person is accepted in most countries, many studies in our review article define elderly as those aged 75 years or older. Geriatr Gerontol Int 2017; 17: 189-201.

Telomere length analysis and preterm infant health: the importance of assay design in the search for novel biomarkers

Preterm infants develop an 'aged' phenotype in comparison with term-born infants, one component of which is adverse metabolic health and, therefore, long-term health follow-up is warranted to identify morbidity. In light of this, the identification and use of biomarkers to aid with prognosis would be a welcome development. Telomeres are repeat sequences at the ends of each chromosome arm known to shorten as a consequence of cellular aging, and in relation to several disease conditions. The hypothesis that expreterm infants manifest alterations in telomere attrition rate is, therefore, one of interest. Analysis of telomere length maybe a plausible technique to predict prognosis in relation to preterm birth, and early life environmental and nutritional exposures. In this article, we review the literature on telomere length analysis in the preterm infant population and examine the tools available to measure telomere length.

Risk factors for hepatocellular carcinoma in hepatitis C patients with normal alanine aminotransferase treated with pegylated interferon and ribavirin

Pegylated interferon (Peg-IFN) plus ribavirin combination therapy is effective in patients with hepatitis C virus (HCV) infection and normal alanine aminotransferase levels (NALT). However, it remains unclear whether the risk of hepatocellular carcinoma (HCC) incidence is actually reduced in virological responders. In this study, HCC incidence was examined for 809 patients with NALT (ALT ≤ 40 IU/mL) treated with Peg-IFN alpha-2b and ribavirin for a mean observation period of 36.2 ± 16.5 months. The risk factors for HCC incidence were analysed by Kaplan-Meier method and Cox proportional hazards model. On multivariate analysis among NALT patients, the risk of HCC incidence was significantly reduced in patients with sustained virological response (SVR) or relapse compared with those showing nonresponse (NR) (SVR vs NR, hazard ratio (HR): 0.16, P = 0.009, relapse vs NR, HR: 0.11, P = 0.037). Other risk factors were older age (≥65 years vs <60 years, HR: 6.0, P = 0.032, 60-64 vs <60 years, HR: 3.2, P = 0.212) and male gender (HR: 3.9, P = 0.031). Among 176 patients with PNALT (ALT ≤ 30 IU/mL), only one patient developed HCC and no significant risk factors associated with HCC development were found. In conclusion, antiviral therapy for NALT patients with HCV infection can lower the HCC incidence in responders, particularly for aged and male patients. The indication of antiviral therapy for PNALT (ALT ≤ 30 IU/mL) patients should be carefully determined.

Treatment for hepatocellular carcinoma in elderly patients: a literature review

An aging society means that the number of elderly patients with cancer is predicted to rise in the future. Hepatocellular carcinoma (HCC) usually develops in patients with hepatitis B virus infection, hepatitis C virus infection, or alcoholic liver disease. The risk of developing HCC is also known to be age-dependent and elderly patients sometimes present with HCC. The increased longevity of the population thus means that more elderly HCC patients are to be expected in the coming years. In general, many elderly patients are not receiving optimal therapy for malignancies, because it is often withheld from them because of perceived minimal survival advantage and the fear of potential toxicity. Comprehensive data with regard to treatment of elderly patients with HCC are currently limited. Furthermore, current guidelines for the management of HCC do not satisfy strategies according to age. Thus, there is urgent need for investigation of safety and clinical outcomes in elderly patients who receive therapy for HCC. In this review, we primarily refer to current knowledge of clinical characteristics and outcome in elderly patients with HCC who underwent different treatment approaches (i.e., surgical resection, liver transplantation, locoregional therapies, and molecular-targeting therapy).

Reduced expression of argininosuccinate lyase is closely associated with postresectional survival in hepatocellular carcinoma: an immunohistochemistry study of 61 cases

Argininosuccinate lyase (ASL) is an important enzyme in the hepatic urea cycle, and catalyzes the reversible reaction of argininosuccinate to arginine and fumarate. Its expression is significantly reduced in some hepatocellular carcinomas (HCC). In this study, we aimed to investigate the correlation of reduced ASL expression and clinicopathologic features and prognosis in HCC patients. Immunohistochemistry was used to determine the expression of ASL in HCC tissues from 61 patients who had undergone hepatic tumor resection. The correlation of ASL expression in HCC with background liver status, viral status, tumor size, portal vein invasion, histopathologic differentiation, early tumor recurrence, sex, and age were assessed with the χ(2) test. Patient survival and survival differences were determined by the Kaplan-Meier method and log-rank test. Cox regression (proportional hazard model) was used for multivariate analysis of prognostic factors. Strong positive staining was found in 39/61 HCCs and normal liver tissues, and reduced ASL staining was found in 22/61 HCCs (36.1%). Patients with low ASL expression had a significantly poorer overall survival and disease-free survival (both P<0.001). Reduced ASL expression in carcinoma tissues was also significantly associated with the tumor-node-metastasis stage and early tumor recurrence, and histopathologic differentiation and portal vein invasion (P<0.05). Cox regression analysis showed that ASL is an independent prognostic marker for HCC. Therefore, reduced ASL expression may be a novel maker for poor prognosis in HCC patients.

Chemoprevention of gastrointestinal cancer: the reality and the dream

Despite substantial progress in screening, early diagnosis, and the development of noninvasive technology, gastrointestinal (GI) cancer remains a major cause of cancer-associated mortality. Chemoprevention is thought to be a realistic approach for reducing the global burden of GI cancer, and efforts have been made to search for chemopreventive agents that suppress acid reflux, GI inflammation and the eradication of Helicobacter pylori. Thus, proton pump inhibitors, statins, monoclonal antibodies targeting tumor necrosis factor-alpha, and nonsteroidal anti-inflammatory agents have been investigated for their potential to prevent GI cancer. Besides the development of these synthetic agents, a wide variety of the natural products present in a plant-based diet, which are commonly called phytoceuticals, have also sparked hope for the chemoprevention of GI cancer. To perform successful searches of chemopreventive agents for GI cancer, it is of the utmost importance to understand the factors contributing to GI carcinogenesis. Emerging evidence has highlighted the role of chronic inflammation in inducing genomic instability and telomere shortening and affecting polyamine metabolism and DNA repair, which may help in the search for new chemopreventive agents for GI cancer.

Hepatocellular telomere length in biliary atresia measured by Q-FISH

BACKGROUND

Liver transplantation for biliary atresia is indicated whenever a Kasai portoenterostomy is considered unfeasible. However, the timing of liver transplantation in biliary atresia has not been precisely defined. Excessive shortening of hepatocellular telomeres may occur in patients with biliary atresia, and therefore, telomere length could be a predictor of hepatocellular reserve capacity.

METHODS

Hepatic tissues were obtained from 20 patients with biliary atresia who underwent LT and 10 age-matched autopsied individuals (mean age, 1.7 and 1.2 years, respectively). Telomere lengths were measured by Southern blotting and quantitative fluorescence in situ hybridization using the normalized telomere-centromere ratio. The correlation between the normalized telomere-centromere ratio for the hepatocytes in biliary atresia and the pediatric end-stage liver disease score was analyzed.

RESULTS

The median terminal restriction fragment length of the hepatic tissues in biliary atresia was not significantly different from that of the control (p = 0.425), whereas the median normalized telomere-centromere ratio of hepatocytes in biliary atresia was significantly smaller than that of the control (p < 0.001). Regression analysis demonstrated a negative correlation of the normalized telomere-centromere ratio with the pediatric end-stage liver disease score in biliary atresia (p < 0.001).

CONCLUSIONS

Telomere length analysis using quantitative fluorescence in situ hybridization could be an objective indicator of hepatocellular reserve capacity in patients with biliary atresia, and excessive telomere shortening supports the early implementation of liver transplantation.

Emerging avenues linking inflammation and cancer

The role of inflammation in carcinogenesis has been extensively investigated and well documented. Many biochemical processes that are altered during chronic inflammation have been implicated in tumorigenesis. These include shifting cellular redox balance toward oxidative stress; induction of genomic instability; increased DNA damage; stimulation of cell proliferation, metastasis, and angiogenesis; deregulation of cellular epigenetic control of gene expression; and inappropriate epithelial-to-mesenchymal transition. A wide array of proinflammatory cytokines, prostaglandins, nitric oxide, and matricellular proteins are closely involved in premalignant and malignant conversion of cells in a background of chronic inflammation. Inappropriate transcription of genes encoding inflammatory mediators, survival factors, and angiogenic and metastatic proteins is the key molecular event in linking inflammation and cancer. Aberrant cell signaling pathways comprising various kinases and their downstream transcription factors have been identified as the major contributors in abnormal gene expression associated with inflammation-driven carcinogenesis. The posttranscriptional regulation of gene expression by microRNAs also provides the molecular basis for linking inflammation to cancer. This review highlights the multifaceted role of inflammation in carcinogenesis in the context of altered cellular redox signaling.

Clinical characteristics of hepatocellular carcinoma in elderly patients

The incidence of hepatocellular carcinoma (HCC) in elderly patients in Japan has been on the increase. The aim of the present study was to evaluate the impact of aging on the clinicopathological findings and the survival of HCC patients. A total of 624 patients with HCC were examined in this study. The patients were classified according to their age at the time of diagnosis: one group comprised younger patients (<75 years; n=544) and the second comprised elderly patients [(≥75 years; n=80, (12%)]. Results showed that there were significantly more female patients (younger:elderly, 22:36; p=0.005), normal livers (younger:elderly, 0.3:6%; p=0.0002), non-viral HCC (younger:elderly, 11:31%; p<0.001) and solitary tumors (younger:elderly, 53:76%; p=0.0008) in the elderly group. Five out of seven (71%) non-B non-C (NBNC) HCC patients who developed HCC in the normal liver were elderly patients. Survival between the younger and elderly HCC groups was not significantly different (younger:elderly, 4.38:3.45 years; p=0.665). Additionally, elderly HCC patients had fewer tumors, more mild underlying liver damage, and more frequent NBNC HCC. Their prognosis was not necessarily poorer than that of the younger HCC patients. Additionally, it appears that elderly patients develop HCC even without fibrosis. Therefore, aging may be a factor affecting hepatocarcinogenesis.

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.

LAPTM4B-35 overexpression is a risk factor for tumor recurrence and poor prognosis in hepatocellular carcinoma

PURPOSE

Lysosomal protein transmembrane 4 beta-35 (LAPTM4B-35) is a tetra-transmembrane glycoprotein that is abundantly localized on membrane-bound organelles including endosomes and lysosomes, and promotes cell proliferation and tumorigenesis through regulation of cell cycle and signaling pathways. The aim of the present study is to determine the potential clinical implications of LAPTM4B-35 expression in hepatocellular carcinoma (HCC).

METHODS

Immunohistochemistry assay was used to determine the expression of LAPTM4B-35 protein in normal and HCC tissues from 71 patients. The correlations of LAPTM4B-35 expression with clinicopathological parameters, including gender, age, background liver, viral status, tumor size, portal vein invasion, histopathological differentiation, serum AFP level, TNM staging and recurrence of HCC were assessed by Chi-squared test. Patient survival and their differences were determined by Kaplan-Meier method and log-rank test. Cox regression (Proportional hazard model) was adopted for multivariate analysis of prognostic factors.

RESULTS

LAPTM4B-35 immunoreactivity was negative or low in normal liver tissues, but high in HCC tissues (51/71, 71.8%). The overexpression of LAPTM4B-35 was significantly associated with recurrence, TNM staging and portal vein invasion of HCC. Patients with high LAPTM4B-35 expression had significantly poorer overall survival (OS) and disease-free survival (DFS) (both P < 0.001) when compared with patients with the low expression of LAPTM4B-35. On multivariate analysis, LAPTM4B-35 expression was found to be an independent prognostic factor for OS and DFS (P = 0.018 and P = 0.001, respectively).

CONCLUSION

LAPTM4B-35 expression showed a strong association with the potencies of recurrence and metastasis and progression of HCC, and that may be applied as a novel marker for the prediction of recurrence and metastasis potency of HCC, and helpful for improving the diagnosis, prognosis and treatment of HCC.

Clinicopathological features of elderly patients with hepatitis C virus-related hepatocellular carcinoma

BACKGROUND

It is well known that the incidence of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV) correlates with progression of liver fibrosis. However, there is little information on the impact of aging on hepatocarcinogenesis. The aim of this study was to elucidate the clinicopathological features of elderly patients with HCV-related HCC.

METHODS

The study subjects were 693 consecutive patients newly diagnosed with HCC with anti-HCV. First, we divided them into a younger group (<70 years) and an elderly group (> or =70 years) and compared clinicopathological features between the two groups. Next, we selected pure HCV-related HCC patients by excluding the patients with other probable factors for hepatocarcinogenesis (anti-HBc, interferon therapy, and alcohol) and compared the two groups again.

RESULTS

Higher platelet count, lower male/female ratio, lower rate of habitual alcohol consumption, and better Child-Pugh class were recognized in the elderly group thant the younger group, statistically. In 133 cases of hepatic resection, fibrosis stage was lower in the elderly than the younger group. After selection of pure HCV-related HCC patients, in a stepwise multi variate analysis, male sex and platelet count <10 x 10(4)/mm3 were significant variables associated with age <70. Regarding the latency period to HCC development, the patients who received a blood transfusion at an older age developed HCC sooner despite their lower grade of fibrosis.

CONCLUSIONS

The elderly patients developed HCC more often, despite their lower grade of fibrosis, compared with the younger patients. In addition to fibrosis, aging could be a factor affecting HCV-related hepatocarcinogenesis.

X protein of hepatitis B virus functions as a transcriptional corepressor on the human telomerase promoter

The X protein of hepatitis B virus (HBx) is essential for transactivation of hepatitis B viral and host cellular genes. It has been specifically implicated in the development of hepatocellular carcinoma; however, the molecular mechanism remains unknown. Telomeres, the DNA-protein complexes at the ends of eukaryotic chromosomes, protect chromosomes from degradation at the terminal regions, fusion with a broken DNA end, and inappropriate recombination. The shortening of telomeres that occurs during hepatocellular carcinogenesis has been well studied. In the present study, we isolated an HBx isoform that resulted in telomere shortening in hepatoma cell lines. We found that this HBx isoform down-regulated the expression of human telomerase by transcriptionally repressing its promoter. To further determine the molecular mechanism, we examined human telomerase promoter and identified myc-associated zinc finger protein (MAZ) as a transcriptional repressor of the promoter. We found that the HBx isoform achieved transcriptional suppression of human telomerase by enhancing MAZ binding to its consensus sequence in the promoter through physical association with MAZ.

CONCLUSION

The data suggest that HBx can induce telomere shortening by acting as a transcriptional corepressor of MAZ on the human telomerase promoter.

Up-regulation of telomere-binding proteins, TRF1, TRF2, and TIN2 is related to telomere shortening during human multistep hepatocarcinogenesis

The telomeric repeat-binding factor 1 (TRF1), TRF2, and the TRF1-interacting nuclear protein 2 (TIN2) are involved in telomere maintenance. We describe the regulation of expression of these genes along with their relationship to telomere length in hepatocarcinogenesis. The transcriptional expression of these genes, TRF1 protein, and telomere length was examined in 9 normal livers, 14 chronic hepatitis, 24 liver cirrhosis, 5 large regenerative nodules, 14 low-grade dysplastic nodules (DNs), 7 high-grade DNs, 10 DNs with hepatocellular carcinoma (HCC) foci, and 31 HCCs. The expression of TRF1, TRF2, TIN2 mRNA, and TRF1 protein was gradually increased according to the progression of hepatocarcinogenesis with a marked increase in high-grade DNs and DNs with HCC foci and a further increase in HCCs. There was a gradual shortening of telomere during hepatocarcinogenesis with a significant reduction in length in DNs. Most nodular lesions (52 of 67) had shorter telomeres than their adjacent chronic hepatitis or liver cirrhosis, and the telomere lengths were inversely correlated with the mRNA level of these genes (P </= 0.001). This was more evident in DNs and DNs with HCC foci. In conclusion, TRF1, TRF2, and TIN2 might be involved in multistep hepatocarcinogenesis by playing crucial roles in telomere shortening.

Telomere shortening and telomerase reactivation in dysplastic nodules of human hepatocarcinogenesis

BACKGROUNDS/AIMS

The maintenance of telomere with telomerase reactivation, vital for carcinogenesis, was studied in human multistep hepatocarcinogenesis for the characterization of borderline lesions.

METHODS

The terminal restriction fragment length (TRFL) and telomerase activity (TA) were examined in 3 chronic hepatitis (CH), 10 cirrhosis, 7 large regenerative nodules (LRNs), 30 low grade dysplastic nodules (LGDNs), 6 high grade DNs (HGDNs), 3 DNs with hepatocellular carcinoma (HCC) foci, 11 HCCs, and 4 normal livers by Southern hybridization and TRAPeze Elisa telomerase detection.

RESULTS

The TRFL and TA showed significant differences between the LGDNs and HGDNs. Most LGDNs had similar levels of TRFL and TA to those of the CH, cirrhosis and LRNs, however, 17% of LGDNs revealed shortening of telomeres up to the levels of HGDNs and 7% of LGDNs showed high levels of TA. The levels of TRFL and TA in HGDNs showed no significant differences from those of DNs with HCC foci and HCCs.

CONCLUSIONS

The shortening of telomeres and reactivation of telomerase occur in the DNs during the early stages of hepatocarcinogenesis, with a significant change in the transition of LGDNs to HGDNs. The characteristics of HGDNs are considered to be closer to those of HCCs.

Telomere length variation and maintenance in hepatocarcinogenesis

BACKGROUND

Despite the recent discovery of interchromosomal telomere length variation, a role for heterogeneity in telomere maintenance has yet to be established. This study investigated the significance of telomere length variation between chromosomes with respect to the association of cancer progression and telomere length regulation.

METHODS

Terminal restriction fragment (TRF) was evaluated in 20 surgically resected hepatocellular carcinoma specimens (HCC), corresponding noncancerous liver tissue specimens (NCL), and in 10 liver tissue specimens with chronic liver diseases devoid of cancer (DOC). Average TRF length (TRF-A) was defined as the point of maximum intensity. Shorter and longer TRF lengths (TRF-S and TRF-L) were defined as the length above which 90% of TRF distribution was involved. A ratio, (TRF-L-TRF-S)/TRF-A, was defined as telomere length dispersion.

RESULTS

The dispersion was significantly larger in HCC than in NCL specimens (P = 0.012) and in NCL than in DOC (P = 0.048). TRF-A and TRF-S were significantly shorter in HCC than in NCL (P = 0.0026, P = 0.0010). In seven patients in whom HCC recurred within 1 year, TRF-A and TRF-S were significantly shorter than in 10 patients in whom recurrence occurred after 1 year (P = 0.018, P = 0.0097). Telomeric repeat binding factor 1 was up-regulated in HCC with elongated TRF-L, whereas expression of human telomerase reverse transcriptase was greater in HCC with a shorter TRF-S.

CONCLUSIONS

These results suggest that telomere length varied through chronic liver diseases by preferentially increasing shorter telomeres, whose length is a good indicator for malignant potential of HCC. Telomere length variation may be a crucial code in telomere maintenance through hepatocarcinogenesis.

Interchromosomal telomere length variation

Despite the recent discovery of interchromosomal telomere length variation, a role for heterogeneity in telomere maintenance has yet to be established. This study aimed to clarify relative telomere length differences between chromosomes. Combined chromosomal sorting and telomeric repeat content analysis in GM130B cells, the relative telomeric repeat content in each chromosome, were calculated. Each chromosome could be isolated except for chromosomes 1 and 2 and chromosomes 9 to 12, which were isolated in a group. Telomere length was correlated with the size of the corresponding chromosome. Concomitant relative telomeric repeat content analysis in each chromosome and terminal restriction fragment analysis using the whole genome revealed that the terminal restriction fragments of each chromosome were heterogenously distributed through the smear of the fragments. This is the first description of an association between telomere length and chromosome size.

Replicative senescence in normal liver, chronic hepatitis C, and hepatocellular carcinomas

There is growing evidence that senescent cells accumulate in vivo and are associated with the aging process in parallel with the progressive erosion of telomeres. Because recent data show that telomere shortening is involved in the pathogenesis of liver cirrhosis, we looked for replicative senescence cells in normal livers, chronic hepatitis C, and hepatocellular carcinoma (HCC). Replicative senescent cells were detected on liver tissue cryosections using expression of a specific marker, senescence-associated beta-galactosidase, a cytoplasmic enzyme detected at pH 6. A total of 57 frozen liver samples (15 normal liver, 32 chronic hepatitis C, and 10 HCCs) were studied. Replicative senescence was graded as absent in 56% of cases (32 of 57) and present in 44% (25 of 57). Replicative senescence was considered present in 3 of 15 normal livers (20%), 16 of 32 chronic hepatitis cases (50%), and 6 of 10 HCCs (60%). In the group of nontumoral livers, the presence of senescent cells in liver was associated with older age (P =.03). In the group with chronic hepatitis C, fibrosis stage, but not activity grade, was significantly correlated with the accumulation of replicative senescent cells (P <.001). Finally, beta-Gal staining in nontumoral tissue was strongly correlated with the presence of HCC in the surrounding liver (P <.001). These results suggest that chronic hepatitis C represents a relevant model of accelerated replicative senescence and that accumulation of replicative senescent cells predispose to HCC development. Detection of replicative senescent cells may then serve as a predictive marker of a hepatocellular carcinoma in the surrounding tissue. HUM PATHOL 32:327-332.

Pathogenesis of hepatocellular carcinoma

The pathogenesis of HCC is poorly understood at present. There is insufficient understanding to propose a robust general model of hepatic carcinogenesis, partly because pathogenic host and environmental factors show significant regional variation, making such generalization difficult. Figure 4 is a model based on data presented in this article. Multiple risk factors for HCC have been identified, including cirrhosis, male gender, increasing patient age, toxins, chronic viral hepatitis, and other specific liver diseases. The understanding of how the individual risk factors result in genetic changes is rudimentary, and there is even less understanding about interactions between risk factors. Future studies should acknowledge the geographic origin of the HCCs studied and consider the effects of cirrhosis, gender, and age. A more rigorous approach to these factors may help explicate the interaction with specific liver diseases so that a comprehensive model of hepatic carcinogenesis can be developed.

Quantitative evaluation of genomic instability as a possible predictor for development of hepatocellular carcinoma: comparison of loss of heterozygosity and replication error

Both loss of heterozygosity (LOH) and replication error (RER) are considered to be phenotypes of genomic instability. To unveil the role of the genomic instability in hepatocarcinogenesis, frequencies of LOH and RER were simultaneously determined in 15 hepatocellular carcinomas (HCCs), surrounding nontumorous liver tissues (SL), and 13 liver tissues with chronic viral hepatitis void of cancer (NC) by referencing peripheral blood leukocytes (PBLs) from the corresponding donor using 18 microsatellite markers spread throughout the genome. LOH was significantly frequent in HCC compared with that in SL or NC (P =.005, P =.0003, respectively) and observed preferentially at particular microsatellite loci, D1S204, D2S123, D8S1106, D9S266, D16S748, and D19S601. Although the higher prevalence of RER was also significant in HCC compared with that in NC (P =.03), in most cases the errors were detected at very low frequencies and random loci. Both LOH and RER tended to appear more prevalently in SL than in NC. The occurrence rate of LOH was higher in the tissues associated with hepatitis B virus (HBV) than with hepatitis C virus (HCV) infection especially in HCC (P =.03). When referencing SL instead of PBLs, the prevalence of LOH and RER in HCC significantly decreased (P =.02 and P =.03, respectively). These results suggest that LOH is closely associated with multistep hepatocarcinogenesis especially under HBV infection, but RER is imperceptibly associated. The quantitative evaluation of the frequency of LOH by referencing PBLs may be a useful predictor for HCC development in chronic liver diseases.

Hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) appears to be declining in Taiwan and potentially in other high-prevalence areas as a consequence of vaccination for hepatitis B virus (HBV). However, there is evidence that the incidence of HCC is increasing in North America and Europe. This appears to be related to the increasing prevalence and duration of hepatitis C virus (HCV) infection in these countries. There is also growing evidence to support an increase in the risk of HCC in patients with HCV who are coinfected with occult HBV (patients who have lost HBV surface antigen but still have detectable HBV DNA either in blood or liver). Occult HBV infection in patients with HCV may be more common than previously thought, and HCC that occurs in this setting appears to have a worse prognosis. There is continuing interest in the effect of interferon therapy on the incidence of HCC in patients with HCV. Several studies from Japan have shown a benefit in patients without cirrhosis, although there are a number of potentially confounding variables that may partly explain these results. Prospective randomized studies are needed to investigate this important question. The molecular biology of HCC and the events of malignant transformation in the liver continue to be areas of intense study. Recently, there has been considerable interest in telomeres, the repeat units on the ends of chromosomes, and the enzyme that maintains these, telomerase. Telomeres shorten with each cell division and can be used to determine the number of divisions a cell has undergone. Eventually they reach a critical length, with further loss resulting in cellular senescence. Telomerase restores telomere length and may help malignant cells escape senescence. Nearly all HCCs have telomerase activity and assessments of telomeres and telomerase may be clinically useful.