Specific molecular signatures of non-tumor liver tissue may predict a risk of hepatocarcinogenesis

Magnetic resonance imaging-based risk factors of hepatocellular carcinoma after direct-acting antiviral therapy: A multicenter observational study

AIM

To determine risk factors associated with hepatocellular carcinoma (HCC) development following direct-acting antiviral (DAA) therapy.

METHODS

We enrolled patients with chronic hepatitis C who underwent direct-acting antiviral therapy and achieved sustained virologic response at 12 weeks between 2012 and 2018. Subsequently, patients were followed up. The primary endpoint was the development of HCC or the date of the last follow up when the absence of HCC was confirmed. Uni- and multivariate Cox proportional hazards models were used to identify factors contributing to HCC development, including gadoxetic acid-enhanced magnetic resonance imaging findings. The cumulative incidence rates of HCC development were calculated using the Kaplan-Meier method, and differences between groups were assessed using the log-rank test.

RESULTS

The final study cohort comprised 482 patients (median age 70.5 years; 242 men). The median follow-up period was 36.8 months. Among 482 patients, 96 developed HCC (19.9%). The 1-, 3-, and 5-year cumulative rates of HCC development were 4.9%, 18.6%, and 30.5%, respectively. Multivariate analysis revealed that age, male sex, history of HCC, and hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were independent risk factors significantly associated with HCC development (p < 0.001-0.04). The highest risk group included patients with both a history of HCC and the presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement (the 1- and 3-year cumulative HCC development rates were 14.2% and 62.2%, respectively).

CONCLUSION

History of HCC and presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were strong risk factors for HCC development following direct-acting antiviral therapy.

Impact of WTAP in small HCC and paired adjacent non-neoplastic liver tissue on recurrence: A cohort study with external extension analysis

Background: To evaluate prognostic value of WTAP levels in tumor and paired adjacent non-neoplastic liver tissues (PANLT) for cases of hepatitis B virus (HBV)-positive Asian small hepatocellular carcinoma (sHCC) patients who received curative partial hepatectomy. Method: The investigation with two external cohorts were included. Associations between hazard risk of recurrence and continuous WTAP levels were investigated with restricted cubic spline models. Cox and inverse probability weighting models were established for survival analysis. Based on interaction effects, further stratification analysis was performed. Landmark analysis was employed to analyze cases of late recurrence. Finally, sensitivity analysis was performed to assess unmeasured confounders. Findings: In an investigation cohort of 307 patients, restricted cubic spline models indicated that hazard risk of recurrence increases with elevated WTAP levels for sHCC and PANLT. However, using Cox and inverse probability weighting models, no significant differences were observed in recurrence-free survival (RFS) between groups with different WTAP levels in sHCC. Multivariate analysis showed that patients with high PANLT WTAP levels had significantly worse RFS (HR 1.567, 95% CI 1.065-2.307; p = 0.023). Based on the significant interaction effect between WTAP levels in sHCC and PANLT, stratification analysis revealed that recurrence risk is more pronounced in patients with high WTAP levels in both PANLT and sHCC. Landmark analysis showed that late recurrence was more likely to occur in patients with high PANLT WTAP levels (HR 2.058, 95% CI 1.113-3.805; p = 0.021). Moreover, the detrimental effects of elevated PANLT WTAP levels on RFS were validated with two external cohorts. Sensitivity analysis confirmed the robustness of results. Conclusion: Increased PANLT WTAP expression levels independently predict high recurrence risk in HBV-positive Asian sHCC patients. Both tumor tissues and PANLT need to be considered together in future clinical practice to obtain a more comprehensive and accurate evaluation for recurrence risk.

Functionalized PAMAM-Based Nanoformulation for Targeted Delivery of 5-Fluorouracil in Hepatocellular Carcinoma

BACKGROUND

Efficacy of a traditional anticancer drug is challenged by adverse effects of the drug including its nonspecific bio-distribution, short half-life and side effects. Dendrimer-based targeted drug delivery sysytem has been considered as a promising strategy to increase targeting ability and reduce adverse effects of anti-cancer drugs.

OBJECTIVE

This study analyzed the feasibility whether the anticancer drug 5-fluorouracil (5-FU) could be delivered by functionalized fifth-poly(amidoamine) (PAMAM) with the peptide WP05 and the acetic anhydride to the liver cancer cells, reducing toxicity of the PAMAM and improving the targeting property of 5-FU during delivery.

METHODS

The functionalized PAMAM-based nanoformulation (WP05-G5.0NHAC-FUA) was fabricated through an amide condensation reaction to improve therapeutic efficacy of 5-Fluorouracil (5-FU) in hepatocellular carcinoma (HCC). The physicochemical structure, particle size, zeta potential, stability and in vitro release characteristics of WP05-G5.0NHAC-FUA were evaluated. In addition, the targeting, biocompatibility, anti-proliferation and anti-migration of WP05-G5.0NHAC-FUA were investigated. The anti-tumor effect of WP05-G5.0NHAC-FUA in vivo was evaluated by constructing xenograft tumor models of hunman hepatoma cells (Bel-7402) implanted in nude mice.

RESULTS

The resultant WP05-G5.0NHAC-FUA displayed spherical-like nanoparticles with the size of 174.20 ± 3.59 nm. Zeta potential and the drug loading of WP05-G5.0NHAC-FUA were 5.62 ± 0.41mV and 28.67 ± 1.25 %, respectively. Notably, the optimized 5-FU-loaded formulation showed greater cytotoxicity with an IC50 of 30.80 ±4.04 μg/mL than free 5-FU (114.93 ±1.43 μg/mL) in Bel-7402 cancer liver cells, but a significantly reduced side effect relative to free 5-FU in L02 normal liver cells. In vivo animal study further confirmed efficient tumor accumulation and enhanced therapeutic efficiency.

CONCLUSION

The developed nanoformulation is a promising platform for the targeting delivery of 5-FU and provides a promising solution for improving the efficacy of hepatocellular carcinoma chemotherapy.

Prognostic Model for the Risk Stratification of Early and Late Recurrence in Hepatitis B Virus-Related Small Hepatocellular Carcinoma Patients with Global Histone Modifications

Background and Aim

To assess the profile of global histone modifications in small hepatocellular carcinoma (small HCC) and identify its prognostic value in predicting recurrence.

Methods

The expression profiles of global histone modifications, including H2AK5AC, H2BK20AC, H3K4me2, H3K9AC, H3K18AC, H4K12AC, and H4R3me2, were evaluated with immunohistochemistry in 335 HBV related small HCC patients. Two histone signature classifiers were then developed using least absolute shrinkage and selection operator Cox regression. A nomogram was built using the classifier and independent risk factors. The performances of the classifier and nomogram were assessed by receiver operating characteristic curves.

Results

Histone modifications were more pronounced in tumor tissues than in adjacent liver tissues. In tumor tissues, the risk score built based on the seven-histone signature exhibited satisfactory prediction efficiency, with an AUC = 0.71 (0.63–0.79) for 2-year survival in the training cohort. Patients with a high risk score had shorter recurrence-free survival than those with a low risk score (HR: 1.96, 95% CI: 1.24–3.08, p = 0.004; HR: 1.95, 95% CI: 1.12–3.42, p = 0.019; and HR: 1.97, 95% CI: 1.39–2.80, p < 0.001 for the training, validation and total cohorts, respectively). Furthermore, the statistical nomogram built using the histone classifier for early recurrence had a C-index = 0.68. In non-neoplastic liver tissues, the hepatic signature based on H3K4me2 and H4R3me2 was related to late recurrence (HR: 2.00, 95% CI: 1.15–3.48, p = 0.01).

Conclusion

Global histone modifications in tumor and adjacent liver tissues are novel predictors of early and late recurrence, respectively, in HBV-related small HCC patients.

Multi-Institutional Development and External Validation of a Nomogram for Prediction of Extrahepatic Recurrence After Curative-Intent Resection for Hepatocellular Carcinoma

BACKGROUNDS

Extrahepatic recurrence of hepatocellular carcinoma (HCC) after surgical resection is associated with unfavorable prognosis. The objectives of the current study were to identify the risk factors and develop a nomogram for the prediction of extrahepatic recurrence after initial curative surgery.

METHODS

A total of 635 patients who underwent curative-intent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. The clinicopathological characteristics, risk factors, and long-term survival of patients with extrahepatic recurrence were analyzed. A nomogram for the prediction of extrahepatic recurrence was established and validated in 144 patients from an external cohort.

RESULTS

Among the 635 patients in the derivative cohort, 283 (44.6%) experienced recurrence. Among patients who recurred, 80 (28.3%) patients had extrahepatic ± intrahepatic recurrence, whereas 203 (71.7%) had intrahepatic recurrence only. Extrahepatic recurrence was associated with more advanced initial tumor characteristics, early recurrence, and worse prognosis versus non-extrahepatic recurrence. A nomogram for the prediction of extrahepatic recurrence was developed using the β-coefficients from the identified risk factors, including neutrophil-to-lymphocyte ratio, multiple lesions, tumor size, and microvascular invasion. The nomogram demonstrated good ability to predict extrahepatic recurrence (c-index: training cohort 0.786; validation cohort: 0.845). The calibration plots demonstrated good agreement between estimated and observed extrahepatic recurrence (p = 0.658).

CONCLUSIONS

An externally validated nomogram was developed with good accuracy to predict extrahepatic recurrence following curative-intent resection of HCC. This nomogram may help identify patients at high risk of extrahepatic recurrence and guide surveillance protocols as well as adjuvant treatments.

A dual-functional nanovehicle with fluorescent tracking and its targeted killing effects on hepatocellular carcinoma cells

All-in-one drug delivery nanovehicles with low cytotoxicity, high clinical imaging tracking capability, and targeted- and controlled-releasing performances are regarded as promising nanoplatforms for tumor theranostics. Recently, the design of these novel nanovehicles by low molecular weight amphiphilic chitosan (CS) was proposed. Based on fluorescent gold nanoclusters (AuNCs), a tumor-targeting nanovehicle (i.e. AuNCs-CS–AS1411) was prepared via electrostatic attraction between AuNC-conjugated chitosan (i.e. AuNCs-CS) and the anti-nucleolin aptamer, AS1411. After that, the anticancer drug methotrexate (MTX) was encapsulated into the nanovehicles and then the dual-functional nano-drug (i.e. MTX@AuNCs-CS–AS1411) was comparatively supplied to the human hepatocellular carcinoma cell line HepG2 and the human normal liver cell line LO2, to exhibit its “all in one” behavior. Under the conditions of the same concentration of MTX, MTX@AuNCs-CS–AS1411 demonstrates more intensive cytotoxicity and apoptosis-inducing activity against HepG2 cells than those against normal LO2 cells, mainly due to the targeting effect of AS1411 on the nucleolins that were found at high levels on the surface of tumor cells, but are at low levels or absent on normal cells. On the other hand, the MTX release from the MTX@AuNCs-CS–AS1411 was much faster in mildly acidic solution than that in neutral pH. Thus, it may provide a possibility to more significantly release MTX in intracellular lysosome of tumor cells, rather than let loose MTX during transport of the drug from blood vessels to tumor tissue. In conclusion, our dual-functional nanovehicle possesses high fluorescence efficiency and photostability, low cytotoxicity, pH-dependent controlled release, high sensitivity and target-specificity to cancer cells which allowed concurrent targeted imaging and delivery in cancer chemotherapies.

Schematic illustration of the synthesis of the MTX@AuNCs-CS–AS1411, and its targeted delivery and imaging of hepatocellular carcinoma cells.

Reduction of T-Box 15 gene expression in tumor tissue is a prognostic biomarker for patients with hepatocellular carcinoma

Genome-wide analysis is widely applied to detect molecular alterations during oncogenesis and tumor progression. We analyzed DNA methylation profiles of hepatocellular carcinoma (HCC), and investigated the clinical role of most heypermethylated of tumor, encodes T-box 15 (TBX15), which was originally involved in mesodermal differentiation. We conducted a genome-wide analysis of DNA methylation of tumor and non-tumor tissue of 15 patients with HCC, and revealed TBX15 was the most hypermethylated gene of tumor (Beta-value in tumor tissue = 0.52 compared with non-tumor tissue). Another validation set, which comprised 58 HCC with radical resection, was analyzed to investigate the relationships between tumor phenotype and TBX15 mRNA expression. TBX15 mRNA levels in tumor tissues were significantly lower compared with those of nontumor tissues (p < 0.0001). When we assigned a cutoff value = 0.5-fold, the overall survival 5-year survival rates of the low-expression group (n = 17) were significantly shorter compared with those of the high-expression group (n = 41) (43.3% vs. 86.2%, p = 0.001). Multivariate analysis identified low TBX15 expression as an independent prognostic factor for overall and disease-free survival. Therefore, genome-wide DNA methylation profiling indicates that hypermethylation and reduced expression of TBX15 in tumor tissue represents a potential biomarker for predicting poor survival of patients with HCC.

Risk Factors for Hepatocellular Carcinoma Recurrence and Survival after Liver Transplantation in Patients with HCV-Related Cirrhosis

Purpose

We aimed to identify prognostic factors for survival and recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) for patients with HCC and hepatitis C virus-related cirrhosis (HCV-cirrhosis).

Methods

This retrospective cohort study followed all adult patients with HCV-cirrhosis who underwent LT because of HCC or had incidental HCC identified through pathologic examination of the explanted liver at a university hospital in Rio de Janeiro, Brazil, over 11 years (1998-2008). We used Cox regression models to assess the following risk factors regarding HCC recurrence or death after LT: age, Model for End-stage Liver Disease score, Child-Pugh classification, alpha-fetoprotein (AFP), whether patients had undergone locoregional treatment before transplantation, the number of packed red blood cell units (PRBCU) transfused during surgery, the number and size of HCC lesions in the explanted liver, and the presence of microvascular invasion and necrotic areas within HCC lesions.

Results

Seventy-six patients were followed up for a median (interquartile range (IQR)) of 4.4 (0.7-6.6) years. Thirteen (17%) patients had HCC recurrence during the follow-up period, and 26 (34%) died. The median survival time was 6.6 years (95% CI: 2.4-12.0), and the 5-year survival was 52.5% (95% CI: 42.3-65.0%). The final regression model for overall survival included four variables: age (hazard ratio (HR): 1.02, 95% CI: 0.96-1.08, P = 0.603), transplantation waiting time (HR: 1.00, 95% CI: 1.00-1.00, P = 0.190), preoperative AFP serum levels (HR: 1.01, 95% CI: 1.00-1.02, P = 0.006), and whether >4 PRBCU were transfused during surgery (HR: 1.15, 95% CI: 1.05-1.25, P = 0.001). The final cause-specific Cox regression model for HCC recurrence included only microvascular invasion (HR: 14.86, 95% CI: 4.47-49.39, P < 0.001).

Conclusion

In this study of LT for HCV-cirrhosis, preoperative AFP levels and the number of PRBCU transfused during surgery were associated with overall survival, whereas microvascular invasion with HCC recurrence.

Effect of epigenetic modulation on cancer sphere

Background : Cancer stem cell properties are highly relevant to the biology of treatment-resistant cancers. Epigenetic modification regulates gene expressions by chromatin remodeling during malignant transformation. The aim of this study was to elucidate the possible strategy for cancer stem cells focusing on epigenetic modification. Methods : We made cancer sphere from HepG2 cells, and we added Histone deacetylase (HDAC) inhibitor, valproic acid to cancer sphere. And we compared methylation status and the gene expression between normal HepG2 and cancer sphere groups, and between cancer sphere and sphere with HDAC inhibitor treatment groups. Results : Valproic acid (VPA) cancelled this spheroid formation. In comparison between normal HepG2 and cancer sphere, the number of methylation status changes more than 0.1 of beta level was 826 probes, and we could isolate some epithelial-mesenchymal transition (EMT) related genes. And VPA reduced the expressions of EMT related genes in sphere with RT-PCR. On the other hand, in comparison between cancer sphere and sphere with VPA treatment, we detected 29 probe of methylation status change, and VPA reduced the expressions of Bcl-6 in sphere. Conclusions : HDAC inhibitor affected the methylation status of cancer stem cells. Histone-acetylation might overcome treatmet-resistant cancer through the regulation of cancer stem cell. J. Med. Invest. 67 : 70-74, February, 2020.

Delivery of Liver-Specific miRNA-122 Using a Targeted Macromolecular Prodrug toward Synergistic Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) poses a great threat to human health. The elegant combination of gene therapy and chemotherapy by nanocarriers has been repeatedly highlighted to realize enhanced therapeutic efficacy relative to monotreatment. However, the leading strategy to achieve the efficient codelivery of the gene and drug remains the electrostatic condensation with the nucleic acid and the hydrophobic encapsulation of drug molecules by the nanocarriers, which suffers substantially from premature drug leakage during circulation and severe off-target-associated side effects. To address these issues, we reported in this study the codelivery of liver-specific miRNA-122 and anti-cancer drug 5-fluorouracil (5-Fu) using a macromolecular prodrug approach, that is, electrostatic condensation with miRNA-122 using galactosylated-chitosan-5-fluorouracil (GC-FU). The delivery efficacy was evaluated comprehensively in vitro and in vivo. Specifically, the biocompatibility of GC-FU/miR-122 nanoparticles (NPs) was assessed by hemolysis activity analysis, BSA adsorption test, and cell viability assay in both normal liver cells (L02 cells) and endothelial cells. The resulting codelivery systems showed enhanced blood and salt stability, efficient proliferation inhibition of HCC cells, and further induction apoptosis of HCC cells, as well as downregulated expression of ADAM17 and Bcl-2. The strategy developed herein is thus a highly promising platform for an effective codelivery of miRNA-122 and 5-Fu with facile fabrication and great potential for the clinical translation toward HCC synergistic therapy.

Identification of Tissue-Specific DNA Methylation Signatures for Thyroid Nodule Diagnostics

PURPOSE

Thyroid cancer is frequently difficult to diagnose due to an overlap of cytologic features between malignant and benign nodules. This overlap leads to unnecessary removal of the thyroid in patients without cancer. While providing some improvement over cytopathologic diagnostics, molecular methods frequently fail to provide a correct diagnosis for thyroid nodules. These approaches are based on the difference between cancer and adjacent thyroid tissue and assume that adjacent tissues are the same as benign nodules. However, in contrast to adjacent tissues, benign thyroid nodules can contain genetic alterations that can be found in cancer.Experimental Design: For the development of a new molecular diagnostic test for thyroid cancer, we evaluated DNA methylation in 109 thyroid tissues by using genome-wide single-base resolution DNA methylation analysis. The test was validated in a retrospective cohort containing 65 thyroid nodules.

RESULTS

By conducting reduced representation bisulfite sequencing in 109 thyroid specimens, we found significant differences between adjacent tissue, benign nodules, and cancer. These tissue-specific signatures are strongly linked to active enhancers and cancer-associated genes. Based on these signatures, we developed a new epigenetic approach for thyroid diagnostics. According to the validation cohort, our test has an estimated specificity of 97% [95% confidence interval (CI), 81-100], sensitivity of 100% (95% CI, 87-100), positive predictive value of 97% (95% CI, 83-100), and negative predictive value of 100% (95% CI, 86-100).

CONCLUSIONS

These data show that epigenetic testing can provide outstanding diagnostic accuracy for thyroid nodules.See related commentary by Mitmaker et al., p. 457.

Genomic structures of dysplastic nodule and concurrent hepatocellular carcinoma

Although high-grade dysplastic nodule (HGDN) is a preneoplastic lesion that precedes hepatocellular carcinoma (HCC), the genomic structures of HGDN in conjunction with HCC remain elusive. The objective of this study was to identify genomic alterations of HGDN and its difference from HCC that may drive HGDN progression to HCC. We analyzed 16 regions of paired HGDN and HCC from 6 patients using whole-exome sequencing to find somatic mutation and copy number alteration (CNA) profiles of HGDN and HCC. The numbers of mutations, driver mutations, and CNAs of HGDNs were not significantly different from those of HCCs. We identified that the CNA gain of 1q25.3-1q42.13 was predominant in the HCCs compared with that in the HGDNs. Two cases (one nodule-in-nodule case and another case with closely attached HCC and HGDN) showed several overlapped driver mutations (CTNNB1 and CEBPA) and CNAs (losses of CDKN2A, RB1, and TP53) between HGDNs and HCCs, suggesting their roles in the early HCC development. The other 4 cases with spatially separated HCCs and HGDNs showed few overlapped alterations between the paired HCCs and HGDNs. Mutations in ERBB2 and CCND1, and CNAs (gains of CTNNB1, MET, and SMO and losses of PTEN, TP53, and SETD2) were identified as "HCC predominant," suggesting their roles in the progression of HGDN to HCC. Our data show that HCCs are direct descendants of HGDNs in some cases, but there is no direct evidence of such relationship in spatially separated cases. Genomic features of HGDN identified in this study provide a useful resource for dissecting clues for the genetic diagnosis of HGDN and HCC.

Precancer in ulcerative colitis: the role of the field effect and its clinical implications

Cumulative evidence indicates that a significant proportion of cancer evolution may occur before the development of histological abnormalities. While recent improvements in DNA sequencing technology have begun to reveal the presence of these early preneoplastic clones, the concept of 'premalignant field' was already introduced by Slaughter more than half a century ago. Also referred to as 'field effect', 'field defect' or 'field cancerization', these terms describe the phenomenon by which molecular alterations develop in normal-appearing tissue and expand to form premalignant patches with the potential to progress to dysplasia and cancer. Field effects have been well-characterized in ulcerative colitis, an inflammatory bowel disease that increases the risk of colorectal cancer. The study of the molecular alterations that define these fields is informative of mechanisms of tumor initiation and progression and has provided potential targets for early cancer detection. Herein, we summarize the current knowledge about the molecular alterations that comprise the field effect in ulcerative colitis and the clinical utility of these fields for cancer screening and prevention.

Genome-wide DNA methylation analysis during non-alcoholic steatohepatitis-related multistage hepatocarcinogenesis: comparison with hepatitis virus-related carcinogenesis

The aim of this study was to clarify the significance of DNA methylation alterations during non-alcoholic steatohepatitis (NASH)-related hepatocarcinogenesis. Single-CpG-resolution genome-wide DNA methylation analysis was performed on 264 liver tissue samples using the Illumina Infinium HumanMethylation450 BeadChip. After Bonferroni correction, 3331 probes showed significant DNA methylation alterations in 113 samples of non-cancerous liver tissue showing NASH (NASH-N) as compared with 55 samples of normal liver tissue (NLT). Principal component analysis using the 3331 probes revealed distinct DNA methylation profiles of NASH-N samples that were different from those of NLT samples and 37 samples of non-cancerous liver tissue showing chronic hepatitis or cirrhosis associated with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection (viral-N). Receiver operating characteristic curve analysis identified 194 probes that were able to discriminate NASH-N samples from viral-N samples with area under the curve values of more than 0.95. Jonckheere-Terptsra trend test revealed that DNA methylation alterations in NASH-N samples from patients without hepatocellular carcinoma (HCC) were inherited by or strengthened in NASH-N samples from patients with HCC, and then inherited by or further strengthened in 22 samples of NASH-related HCC (NASH-T) themselves. NASH- and NASH-related HCC-specific DNA methylation alterations, which were not evident in viral-N samples and 37 samples of HCC associated with HBV or HCV infection, were observed in tumor-related genes, such as WHSC1, and were frequently associated with mRNA expression abnormalities. These data suggested that NASH-specific DNA methylation alterations may participate in NASH-related multistage hepatocarcinogenesis.

What influences preneoplastic colorectal lesion recurrence?

The hypothesis of the local recurrence of preneoplastic lesions was first put forward in the 1950s. Disease recurrence may result from an inherent imbalance in cell proliferation that promotes carcinogenesis in apparently normal mucosa. Our review sheds light on how early preneoplastic lesions could be used to diagnose relapsed preneoplastic and, developing neoplastic lesions. We focus in detail on the clinical-pathological and molecular features of adenoma subtypes and their role in relapsed adenoma and their development into colorectal carcinoma. Moreover, we include the data available on microbiota and its metabolites and their role in recurrence. We strongly believe that a significant improvement could be achieved in colorectal screening by introducing personalized endoscopic surveillance for polyp-bearing patients on the basis of the presence of molecular markers that are predictive of recurrence.

Molecular alterations in the carcinogenesis and progression of hepatocellular carcinoma: Tumor factors and background liver factors

Although hepatocellular carcinoma (HCC) is associated with poor prognosis worldwide, the molecular mechanisms underlying the carcinogenesis and progression of this disease remain unclear. Several tumor characteristics have previously been demonstrated to be prognostic factors of survival following hepatic resection, or the recurrence of HCC or other types of cancer. Comparisons of normal tissues and HCC tumor tissues have revealed the presence of numerous molecular alterations in HCC, including genetic and epigenetic mechanisms, particularly mutations in certain genes and DNA methylation in the promoter regions of tumor-suppressor genes. A number of studies have previously used array analysis to detect variations in the expression levels of cancer-associated genes and microRNAs, and in DNA methylation. However, an investigation of HCC tumor tissues may not determine the effect of noncancerous liver tissues (background liver) in patients with HCC. As HCC may recur multicentrically following resection, a damaged or chronically diseased HCC background liver may be considered as a pre-cancerous organ. Therefore, the influence of the background liver on HCC requires further study. Detailed studies regarding the background liver may be essential for the improved understanding of the carcinogenesis and progression of this malignancy; however only a few studies have investigated the microenvironment of the HCC background liver. The present review discusses prior molecular studies of hepatocarcinogenesis that focus on HCC and background liver tissues.

A Hepatocellular Carcinoma Aggressiveness Index and Its Relationship to Liver Enzyme Levels

BACKGROUND

Prognosis in hepatocellular carcinoma (HCC) is influenced by both liver and tumor factors, which have been considered independent influences. However, recent evidence has shown that the underlying liver also has prognostic information.

AIMS

To investigate possible relationships between liver function parameters and HCC aggressiveness indices.

METHODS

A large HCC patient database with baseline clinical information and survival data was retrospectively examined.

RESULTS

Data on 756 HCC patients with normal bilirubin were examined for a relationship between serum liver enzymes and 4 HCC aggressiveness indices of maximum tumor diameter, portal vein invasion, tumor multifocality or serum alpha-fetoprotein levels. An association was found between elevated enzyme levels and increased HCC aggressiveness. An aggressiveness index was constructed from the 4 indices and expressed as a sum of their scores, which in turn reflected 3 survival groups. In a Cox model, the hazard ratios for each of the groups were significantly different.

CONCLUSIONS

Statistically significant correlations were found between standard liver function parameters and HCC aggressiveness. A composite aggressiveness index was constructed, yielding 3 groups with different survival probabilities. These findings support the concept of the importance of the underlying liver in relation to HCC biology.

Epigenetic field cancerization in gastrointestinal cancers

Epigenetic alterations, including aberrant DNA methylation, play an important role in human cancer development. Importantly, epigenetic alterations are reversible and can be targets for therapy or chemoprevention for various types of human cancers. A field for cancerization, or a field defect, is formed by the accumulation of genetic and/or epigenetic alterations in normal-appearing tissues and can correlate with risk of cancer development. Thus, a better understanding of epigenetic field cancerization may represent a useful translational opportunity for cancer risk assessment, including previous history and exposure to carcinogenic factors, and for cancer prevention. In this article, we summarize current knowledge regarding epigenetic field cancerization and its clinical implications in gastrointestinal cancers, including colorectal cancer, gastric cancer and esophageal cancer.

Hypermethylation of ACP1, BMP4, and TSPYL5 in Hepatocellular Carcinoma and Their Potential Clinical Significance

BACKGROUND AND AIM

Aberrant methylation of specific genes is frequent event in hepatocellular carcinoma (HCC). Our present study aims to explore the methylation levels of acid phosphatase locus 1 (ACP1), bone morphogenetic protein 4 (BMP4), and testis-specific protein, Y-encoded-like 5 (TSPYL5) and their potential clinical applications in HCC.

METHODS

The methylation levels of ACP1, BMP4 and TSPYL5 were analyzed in 188 HCC tissues, 163 matched adjacent non-tumor tissues, and 29 normal liver tissues using a method of methylation-sensitive restriction enzyme-based quantitative PCR, and their associations with clinicopathological features and prognosis were evaluated.

RESULTS

Compared with adjacent non-tumor tissues and normal liver tissues, the methylation levels of ACP1, BMP4, and TSPYL5 were significantly increased in HCC tissues (All p < 0.0001). The methylation of each individual gene could distinguish HCC tissues well from adjacent non-tumor tissues with the area under the receiver operating characteristic curves (AUC) of 0.753, 0.785 and 0.917, respectively. Furthermore, a higher methylation of BMP4 was statistically associated with worse disease-free survival (p = 0.006) and might be an independent unfavorable factor for disease-free survival by univariate and multivariate analysis (p = 0.011, HR 3.431, 95 % CI 1.333-8.833).

CONCLUSIONS

Our findings suggest that hypermethylation of ACP1, BMP4, and TSPYL5 are common events in HCC and could be used as potentially detectable biomarkers in HCC tissues. Moreover, BMP4 could be potentially served as a methylated biomarker to predict recurrence and metastasis after hepatectomy for HCC patients. However, their potential clinical application value need to be further clarified.

Targeted deep DNA methylation analysis of circulating cell-free DNA in plasma using massively parallel semiconductor sequencing

AIM

To set up a targeted methylation analysis using semiconductor sequencing and evaluate the potential for studying methylation in circulating cell-free DNA (cfDNA).

MATERIALS & METHODS

Methylation of VIM, FBLN1, LTBP2, HINT2, h19 and IGF2 was analyzed in plasma cfDNA and white blood cell DNA obtained from eight hepatocellular carcinoma patients and eight controls using Ion Torrent™ PGM sequencer.

RESULTS

h19 and IGF2 showed consistent methylation levels and methylation was detected for VIM and FBLN1, whereas LTBP2 and HINT2 did not show methylation for target regions. VIM gene promoter methylation was higher in HCC cfDNA than in cfDNA of controls or white blood cell DNA.

CONCLUSION

Semiconductor sequencing is a suitable method for analyzing methylation profiles in cfDNA. Furthermore, differences in cfDNA methylation can be detected between controls and hepatocellular carcinoma cases, even though due to the small sample set these results need further validation.