Hepatocellular carcinoma--survival and clinical characteristics in relation to various histologic molecular markers in Western patients

Major histocompatibility complex class II in the tumor microenvironment: functions of nonprofessional antigen-presenting cells

Major histocompatibility complex class-II-restricted presentation by nonprofessional antigen-presenting cells in the tumor microenvironment can regulate antitumor T-cell responses. In murine models, tumor cell-specific MHC class II expression decreases in vivo tumor growth, dependent on T cells. Tumor cell-specific MHC class II expression is associated with improved survival and response to immune checkpoint inhibitors in human cancers. Antigen-presenting cancer-associated fibroblasts (apCAF) present MHC class-II-restricted antigens and activate CD4 T cells. The role of MHC class II on apCAFs depends on the cell of origin. MHC class II on tumoral lymphatic endothelial cells leads to expansion of regulatory T cells and increased in vivo tumor growth.

Role of Tetraspanins in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is characterized by high prevalence, morbidity, and mortality. Liver cancer is the sixth most common cancer worldwide; and its subtype, HCC, accounts for nearly 80% of cases. HCC progresses rapidly, and to date, there is no efficacious treatment for advanced HCC. Tetraspanins belong to a protein family characterized by four transmembrane domains. Thirty-three known tetraspanins are widely expressed on the surface of most nucleated cells and play important roles in different biological processes. In our review, we summarize the functions of tetraspanins and their underlying mechanism in the life cycle of HCC, from its initiation, progression, and finally to treatment. CD9, TSPAN15, and TSPAN31 can promote HCC cell proliferation or suppress apoptosis. CD63, CD151, and TSPAN8 can also facilitate HCC metastasis, while CD82 serves as a suppressor of metastasis. TSPAN1, TSPAN8, and CD151 act as prognosis indicators and are inversely correlated to the overall survival rate of HCC patients. In addition, we discuss the potential of role of the tetraspanin family proteins as novel therapeutic targets and as an approach to overcome drug resistance, and also provide suggestions for further research.

Activated platelets inhibit hepatocellular carcinoma cell differentiation and promote tumor progression via platelet-tumor cell binding

Lack of differentiation in hepatocellular carcinoma (HCC) is associated with increased circulating platelet size. We measured platelet activation and plasma adenosine diphosphate (ADP) levels in HCC patients based on differentiation status. Local platelet accumulation and platelet-hepatoma cell binding were measured using immunohistochemistry (IHC) or flow cytometry. Using a xenograft assay in NON/SCID mice, we tested the effects of the anti-platelet drug clopidogrel on platelet activation, platelet infiltration, platelet-tumor cell binding and tumor cell differentiation. HCC patients with poor differentiation status displayed elevated platelet activation and higher ADP levels. Platelets accumulated within poorly differentiated tissues and localized at hepatoma cell membranes. Platelet-tumor cell binding was existed in carcinoma tissues, largely mediated by P-selectin on platelets. NOD/SCID mice with xenograft tumors also exhibited increased platelet activation and platelet-tumor cell binding. Clopidogrel therapy triggered hepatoma cell differentiation by attenuating platelet activation and platelet-tumor cell binding. TCF4 knockdown promoted HepG-2 cell differentiation and inhibited tumor formation, and TCF4 could be the potential downstream target for clopidogrel therapy.

Candidate genes responsible for early key events of phenobarbital-promoted mouse hepatocellular tumorigenesis based on differentiation of regulating genes between wild type mice and humanized chimeric mice

Phenobarbital (PB) is a nongenotoxic hepatocellular carcinogen in rodents. PB induces hepatocellular tumors by activating the constitutive androstane receptor (CAR). Some previous research has suggested the possible involvement of epigenetic regulation in PB-promoted hepatocellular tumorigenesis, but the details of its molecular mechanism are not fully understood. In the present study, comprehensive analyses of DNA methylation, hydroxymethylation and gene expression using microarrays were performed in mouse hepatocellular adenomas induced by a single 90 mg kg-1 intraperitoneal injection dose of diethylnitrosamine (DEN) followed by 500 ppm PB in the diet for 27 weeks. DNA modification and expression of hundreds of genes are coordinately altered in PB-induced mouse hepatocellular adenomas. Of these, gene network analysis showed alterations of CAR signaling and tumor development-related genes. Pathway enrichment analysis revealed that differentially methylated or hydroxymethylated genes belong mainly to pathways involved in development, immune response and cancer cells in contrast to differentially expressed genes belonging primarily to the cell cycle. Furthermore, overlap was evaluated between the genes with altered expression levels with 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) alterations in mouse hepatocellular adenoma induced by DEN/PB and the genes with altered expression levels in the liver of CD-1 mice or humanized chimeric mice treated with PB for 7 days. With the integration of transcriptomic and epigenetic approaches, we detected candidate genes responsible for early key events of PB-promoted mouse hepatocellular tumorigenesis. Interestingly, these genes did not overlap with genes altered by the PB treatment of humanized chimeric mice, thus suggesting a species difference between the effects of PB in mouse and human hepatocytes.

Hepatocellular carcinoma: Exploring the impact of ethnicity on molecular biology

Hepatocellular carcinoma (HCC) is the sixth most common cancer in the world and the third leading cause of cancer-related death. The high rate of diagnosis in non-curable stages and the lack of novel active treatments make it necessary to review all the possible sources of misleading results in this scenario. The incidence of HCC shows clear geographical variation with higher annual incidence in Asia and Africa than in Western countries; we aimed to review the literature to find if there are different trends in the main activated molecular pathways. Hyperactivation of RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signalling and epithelial to mesenchymal transition (EMT) process are more prevalent in the Western population; however, fibroblast growth factor (FGF), transforming growth factor β (TGFβ) and Notch pathways seems to be more relevant in Asian population. Whether these variations just reflect the distinct distribution of known causes of HCC or proper ethnical differences remain to be elucidated. Nevertheless, these clearly different patterns are relevant to regional or worldwide clinical trial design. If this information is neglected by sponsors and researchers the rate of failure in HCC trials will not improve.

Management of hepatocellular carcinoma: Predictive value of immunohistochemical markers for postoperative survival

Hepatocellular carcinoma (HCC) accounts for over 90% of all primary liver cancers. With an ever increasing incidence trend year by year, it has become the third most common cause of death from cancer worldwide. Hepatic resection is generally considered to be one of the most effective therapies for HCC patients, however, there is a high risk of recurrence in postoperative HCC. In clinical practice, there exists an urgent need for valid prognostic markers to identify patients with prognosis, hence the importance of studies on prognostic markers in improving the prediction of HCC prognosis. This review focuses on the most promising immunohistochemical prognostic markers in predicting the postoperative survival of HCC patients.

Tetraspanin-enriched microdomains and hepatocellular carcinoma progression

As in many tumors, heterogeneity within the cell population is one of the main features of hepatocellular carcinoma (HCC). Heterogeneity results from the ability of tumor to produce multiple subpopulations of cells with diverse genetic, biochemical and immunological characteristics. Little is known about how heterogeneity emerges and how it is maintained. Fluctuations in single cells can be masked or completely misrepresented when cell populations are analyzed. It has become exceedingly apparent that the utility of measurement based on the analysis of bulk specimens is limited by intra-tumor genetic and epigenetic heterogeneity, as characteristics of the most abundant cell type might not necessarily predict the properties of cell populations. Yet, such non-uniformities often unveil molecular patterns that can represent mechanisms of tumor progression. Interestingly, variability among single cells in a population may arise from different responses to intrinsic and extrinsic perturbations mainly mediated by the plasma membrane. The association of certain proteins, including tetraspanins, and lipids in specific location on the plasma membrane constitutes specialized structure called tetraspanin-enriched microdomains (TEMs). TEMs organization in cancer may reveal essential clues for understanding pathogenic mechanisms underlying cancer progression. Along these lines, TEMs and HCC progression represent a valuable paradigm for gaining a deeper understanding of such mechanisms.

Current evidence on the relationship between murine double minute 2 T309G polymorphism and esophageal cancer susceptibility

The relationship between murine double minute 2 (MDM2) T309G polymorphism and esophageal cancer risk has been discussed with discrepant results. The aim of our study is to investigate the systematic association between the potentially functional MDM2 T309G polymorphism and esophageal cancer risk. Eligible studies were included through searching the databases of PubMed, EMBASE, and Chinese National Knowledge Infrastructure (up to April 2014). The crude odds ratio (OR) and 95% confidence interval (CI) were used to estimate the strength of the association. Six published case-control studies, including 1899 cases and 3016 controls, were identified. Overall, our study suggested that MDM2 T309G polymorphism was significantly associated with increased risk of esophageal cancer (TT vs. GG: OR = 0.77, 95% CI = 0.65-0.90, P = 0.002; T vs. G: OR = 0.88, 95% CI = 0.81-0.96, P = 0.002). In subgroup analyses stratified by source of controls, ethnicity, and quality score assessment, respectively, similar results were obtained (TT vs. GG: OR = 0.65, 95% CI = 0.48-0.89, P = 0.007 for hospital-based studies; T vs. G: OR = 0.90, 95% CI = 0.81-0.99, P = 0.04 for population-based studies; and T vs. G: OR = 0.85, 95% CI = 0.78-0.93, P = 0.004 for Asians). The results of Begg's test and Egger's test did not suggest publication bias in the studies. Therefore, the MDM2 T309G polymorphism may be significantly associated with increased esophageal cancer risk, especially among Asians.

Autoantibody response to murine double minute 2 protein in immunodiagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Although new therapeutic strategies have been continuously developed and applied to clinical treatment for HCC, the prognosis is still very poor. Thus, early detection of HCC may enhance effective and curative management. In this study, autoantibody responses to MDM2 protein in HCC patient's serum were evaluated by enzyme-linked immunosorbent assay (ELISA) and part sera were evaluated by Western blotting and indirect immunofluorescence assay. Immunohistochemistry (IHC) over tissue array slides was also performed to analyze protein expression of MDM2 in HCC and control tissues. The prevalence of autoantibodies against MDM2 was significantly higher than that in liver cirrhosis (LC), chronic hepatitis (CH), and normal human sera (NHS). The average titer of autoantibodies against MDM2 in HCC serum was higher compared to that in LC, CH, and NHS. A high titer of autoantibodies against MDM2 in ELISA could be observed in the serum in 6 to 9 months before the clinical diagnosis of HCC in the serum of several HCC patients with serial bleeding samples. Our preliminary data indicate that MDM2 and anti-MDM2 system may be a potential biomarker for early stage HCC screening and immunodiagnosis.

TP53 immunohistochemical expression is associated with the poor outcome for hepatocellular carcinoma: evidence from a meta-analysis

Various studies examined the relationship between p53 expression with the clinical outcome in patients with hepatocellular carcinoma (HCC), but yielded conflicting results. Electronic databases updated to July 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between p53 expression and survival of patients with HCC. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of 24 studies that evaluated the correlation between p53 expression and survival in patients with HCC. Combined hazard ratios suggested that p53 expression had an unfavorable impact on overall survival (OS) (HR (hazard ratio) = 1.55, 95 % CI (confidence interval) 1.36-1.74) and disease-free survival (DFS) (HR = 1.54, 95 % CI 1.21-1.88) in patients with HCC. No significant heterogeneity was observed among 20 studies for OS (P = 0.786) and among 11 studies for DFS (P = 0.698). P53 expression indicates a poor prognosis for patients with hepatocellular carcinoma.

Prognostic significance of TP53 expression for patients with hepatocellular carcinoma: a meta-analysis

BACKGROUND

Various studies evaluated the relationship between p53 expression and the clinical outcome in patients with hepatocellular carcinoma (HCC), but yielded conflicting results.

METHODS

Electronic databases updated to Dec 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between p53 expression and survival of patients with HCC. Survival data were aggregated and quantitatively analyzed.

RESULTS

We performed a meta-analysis of 24 studies that evaluated the correlation between p53 expression and survival in patients with HCC. Combined hazard ratios (HRs) suggested that p53 expression had an unfavorable impact on overall survival (OS) [HR =1.64, 95% confidence interval (CI): 1.40-1.85], and disease free survival (DFS) (HR =1.57, 95% CI: 1.26-1.87) in patients with HCC.

CONCLUSIONS

p53 expression indicates a poor prognosis for patients with HCC.

MDM2 SNP309T>G polymorphism and hepatocellular carcinoma risk: a meta-analysis

Case-control studies on the association between mouse double-minute 2 homolog (MDM2) SNP309T>G polymorphism and hepatocellular carcinoma have provided either controversial or inconclusive results. To clarify the effect of MDM2 SNP309T>G polymorphism on the risk of hepatocellular carcinoma, a meta-analysis of all case-control observational studies was performed. Pooled odds ratios (ORs) for various polymorphisms were estimated using random and fixed effects models. The Q-statistic was used to evaluate the homogeneity, and Egger and Begg tests were used to assess publication bias. Overall, the MDM2 SNP309T>G polymorphism was associated with a risk of hepatocellular carcinoma (OR = 0.68; 95% CI = 0.54-0.85 for allele contrast, p = 0.0005, phet = 0.004). The contrast of homozygotes and the recessive and dominant models produced the same pattern of results as the allele contrast. In the analysis stratified by ethnicity, significant associations were found in the Caucasian population in all of the genetic models. In addition, heterogeneity disappeared in subgroups of Caucasian subjects. Our pooled data suggest evidence for a major role of MDM2 SNP309T>G polymorphism in the carcinogenesis of hepatocellular carcinoma, especially among Caucasian populations.

Cellular reprogramming and hepatocellular carcinoma development

Hepatocellular carcinoma (HCC) is one of the most common cancers, and is also the leading cause of death worldwide. Studies have shown that cellular reprogramming contributes to chemotherapy and/or radiotherapy resistance and the recurrence of cancers. In this article, we summarize and discuss the latest findings in the area of cellular reprogramming in HCC. The aberrant expression of transcription factors OCT4, KLF4, SOX2, c-MYC, NANOG, and LIN28 have been also observed, and the expression of these transcription factors is associated with unfavorable clinical outcomes in HCC. Studies indicate that cellular reprogramming may play a critical role in the occurrence and recurrence of HCC. Recent reports have shown that DNA methylation, miRNAs, tumor microenvironment, and signaling pathways can induce the expression of stemness transcription factors, which leads to cellular reprogramming in HCC. Furthermore, studies indicate that therapies based on cellular reprogramming could revolutionize HCC treatment. Finally, a novel therapeutic concept is discussed: reprogramming control therapy. A potential reprogramming control therapy method could be developed based on the reprogramming demonstrated in HCC studies and applied at two opposing levels: differentiation and reprogramming. Our increasing understanding and control of cellular programming should facilitate the exploitation of this novel therapeutic concept and its application in clinical HCC treatment, which may represent a promising strategy in the future that is not restricted to liver cancer.

The fibrotic microenvironment as a heterogeneity facet of hepatocellular carcinoma

It has long been recognized that hepatocellular carcinoma heterogeneity arises from variation in the microenvironment or from genomic alteration. Only recently it has become clear that non-genetic alterations, such as cytoskeletal rearrangement, protein localization and formation of protein complexes, are also involved in generating phenotype variability. These proteome fluctuations cause genetically identical cells to vary significantly in their responsiveness to microenvironment stimuli. In the cirrhotic liver pre-malignant hepatocytes are continuously exposed to abnormal microenvironments, such as direct contact with activated hepatic stellate cells (HSCs) and extracellular matrix components. These abnormal environments can have pronounced influences on the epigenetic aspects of cells, translating into abnormal phenotypes. Here we discuss non-genetic causes of phenotypic heterogeneity of hepatocellular carcinoma, with an emphasis on variability of membrane protein complexes and transferred functions raising important implications for diagnosis and treatment.

MicroRNA-22 expression in hepatocellular carcinoma and its correlation with ezrin protein

Objective

Expression of microRNA-22 (miR-22) and ezrin protein (a membrane–cytoskeleton linking protein) in hepatocellular carcinoma (HCC) was investigated.

Methods

Specimens of HCC and paracancerous tissue (control; ∼5 cm away from tumour tissue) were collected from 192 patients. miR-22 expression was detected by real-time polymerase chain reaction; ezrin protein expression in tumour tissue was assessed immunohistochemically. Associations between miR-22 expression and clinicopathological features of HCC and ezrin expression were analysed.

Results

miR-22 expression was lower in HCC tissue than in paracancerous tissue samples (median relative expression 0.676 versus 1.000 for control tissue). Expression of miR-22 was significantly associated with histological differentiation (relative expression 0.431 for lower grades of differentiation versus 0.918 for higher grades), and was associated with lymphatic metastasis (relative expression 0.518 if metastasis was present, 0.919 if absent). Survival time was shorter in patients with low miR-22 expression than in those with high expression (31.0 ± 2.6 versus 52.2 ± 5.1 months). There was a significant negative correlation between the expression of miR-22 and that of ezrin.

Conclusions

miR-22 is downregulated in HCC and its expression is associated with the differentiation, metastasis and prognosis of the carcinoma. Ezrin is a potential regulatory protein of miR-22.

MDM2 is a useful prognostic biomarker for resectable gastric cancer

Expression of MDM2 protein appears to be increased in malignancy and correlated to prognosis of tumors, but its role in gastric cancer remains controversial. Our recent investigations indicated that JWA was a novel candidate biomarker for gastric cancer. To evaluate the impact of MDM2 protein expression alone, and in combination with JWA, on the prognostic and predictive of patients with resectable gastric cancer, expression of MDM2 and JWA were examined by immunohistochemistry in three large cohorts (total n = 1131) of patient with gastric cancer. We found that MDM2 protein levels were significantly upregulated in gastric cancer (70.4%, 57 of 81) compared with adjacent non-cancerous tissues. High tumoral MDM2 expression significantly correlated with clinicopathologic characteristics, as well as with shorter overall survival (OS; P < 0.001 for all cohorts) in patients without adjuvant treatment. The effect of adjuvant fluorouracil-leucovorin-oxaliplatin (FLO) in improving OS compared with surgery alone was evident only in the high MDM2 group (hazard ratio = 0.57; 95% confidence interval, 0.37-0.89; P = 0.013). Furthermore, knockdown of MDM2 and overexpression of JWA had a synergistic effect on suppression of gastric cancer cell proliferation and migration. Patients with low MDM2 and high JWA expression had a better outcome of survival compared with the other groups (P < 0.001 for all cohorts). For the first time, our data suggest that MDM2 is a potent prognostic and predictive factor for benefit from adjuvant fluorouracil-leucovorin-oxaliplatin chemotherapy in resectable gastric cancer. The combination of MDM2 expression and JWA could serve as a more effective candidate prognostic biomarker for gastric cancer.

MDM2 SNP309T>G polymorphism increases susceptibility to hepatitis B virus-related hepatocellular carcinoma in a northeast Han Chinese population

BACKGROUND AND AIMS

The murine double minute 2 (MDM2) gene encodes a negative regulator of the tumour protein p53. A single nucleotide polymorphism (SNP) in MDM2 promoter, SNP309 T > G, has been showed to influence MDM2 protein expression and accelerate tumour formation. To investigate further the role of this locus, we examined the association of the SNP with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in a northeast Han Chinese population.

METHODS

MDM2 SNP309 was genotyped in 310 HBV-related HCC patients, 314 non-HCC subjects with HBV infection and 480 healthy controls by using a PCR-RFLP method.

RESULTS

Significant differences of MDM2 SNP309 were detected between HBV-related HCC patients and healthy controls (OR 1.729, 95%CI 1.369-2.183, P < 0.0001) or non-HCC subjects with HBV infection (OR 1.351, 95% CI 1.060-1.722, P = 0.015) by a logistic regression analysis. Our data also revealed that subjects with the G allele had higher HBV-related HCC susceptibility than those with the T allele in various genetic models. In a meta-analysis, where we pooled our data with other published studies, the association between this loci and the disease was further confirmed (pooled OR 1.54, 95% CI 1.37-1.72, P < 0.0001).

CONCLUSIONS

These results suggested that the MDM2 SNP309 might influence the risk of developing HBV-related HCC in a northeast Han Chinese population.

Alterations of TP53 are associated with a poor outcome for patients with hepatocellular carcinoma: evidence from a systematic review and meta-analysis

BACKGROUND

The prognostic significance of p53 aberration in hepatocellular carcinoma (HCC) remains inconclusive. This systematic review and meta-analysis aimed to provide comprehensive evidence on the association of p53 alterations with recurrence-free survival (RFS) and overall survival (OS) in HCC patients.

METHODS

Systematic literature searches were conducted until July 2010. Meta-analysis was performed to estimate prognostic effects of p53 alterations on patient outcomes in HCC. Sensitivity and subgroup analyses were also conducted in the meta-analysis.

RESULTS

Thirty-seven studies (7 tumour p53 mutation, 23 tumour p53 expression and 7 serum anti-p53 antibodies) were included in the systematic review and meta-analysis. The average percentages of p53 mutation, p53 expression upregulation and anti-p53 antibody level elevation in HCC patients were 31.5%, 35.0% and 23.8%, respectively. Tumour p53 alterations were associated significantly with poor patient outcomes in HCC: the summary hazard ratio (HR) of mutant p53 versus wild type p53 phenotype was 2.58 [95% confidence interval (CI): 1.96-3.41] for OS and 3.19 [95% CI: 2.21-4.60] for RFS, respectively; and the summary HR of upregulated p53 expression versus low/undetectable p53 expression was 1.68 [95% CI: 1.49-1.90] for OS and 1.89 [95% CI: 1.34-2.66] for RFS, respectively. However, elevated serum anti-p53 antibody was only associated with poor OS in HCC group with a high proportion of (≥ 50%) of hepatitis C virus (HCV) infection [HR: 1.92; 95% CI: 1.30-2.85]. Moreover, sensitivity analyses showed that the results of meta-analyses were not altered.

CONCLUSION

HCC patients with p53 mutation and upregulated expression in tumour tissue have a shorter OS and RFS than patients with wild type p53 and low/undetectable p53 expression. However, the prognostic value of serum anti-p53 antibody is required to be further examined.

Comparison of hepatocellular carcinoma in American and Asian patients by tissue array analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Although some epidemiologic and etiologic differences between Asian and Western HCC are known, detailed comparative studies with pathologic correlations have not been performed.

METHODS

Paraffin sections of resected HCC specimens from Memorial Sloan-Kettering Cancer Center and Korea University Medical Center were used to construct tissue microarrays. Immunohistochemical staining of microarray sections was performed using antibodies against markers of proliferation and regulators of cell cycle. Patient data were correlated with staining results.

RESULTS

When comparing both cohorts, significant differences were found in expression of p53 and MDM2. In the Asian group, more frequent positive staining for p53 (24%) was observed compared with the American group (9%; P = 0.037). For MDM2, 26% of American cases stained positive compared with 2% of Asian cases (P = 0.0003). No significant differences were found in expression of Ki67, p21, p27, cyclin D1, or bcl2. Female gender, vascular invasion, and lack of viral hepatitis infection correlated with positive MDM2 staining.

CONCLUSION

These data likely correlate with differences in molecular pathogenesis of HCC based on racial and regional differences. These findings may have implications in choice of molecular targeted therapies based on patient ethnicity.

MDM2 SNP309T>G polymorphism with hepatocellular carcinoma risk: a meta-analysis

BACKGROUND AND AIMS

The murine double minute 2 (MDM2) gene encodes a negative regulator of the tumor protein p53. A single nucleotide polymorphism (SNP) in MDM2 promoter, SNP309 T>G, has been reported to alter MDM2 protein expression and accelerate tumor formation in humans. Studies investigating the association between the polymorphism and human hepatocellular carcinoma (HCC) risk reported conflicting results. We performed a meta-analysis to explore the association of this polymorphism and HCC risk.

METHODS

All eligible studies published were searched for in PubMed. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were assessed for the association using fixed- and random-effects models.

RESULTS

We identified five case-control studies including 738 cases and 1014 controls for the present meta-analysis. In studies with limited data, we detected significant associations for all genetic models in the overall analysis (OR = 2.51, 95% CI = 1.88-3.36 for GG vs. TT, p <0.001, P(het) = 0.666; OR = 1.71, 95% CI = 1.35-2.18 for TG vs. TT, p <0.001, P(het) = 0.925; OR = 1.94, 95% CI = 1.54-2.43 for dominant model TG + GG vs. TT, p <0.001, P(het) = 0.772; OR = 1.74, 95% CI = 1.39-2.20 for recessive model GG vs. TT + TG, p <0.001, P(het) = 0.656). Moreover, in the subgroup analysis based on Hardy-Weinberg equilibrium (HWE) in controls, sample size, and ethnicity, significant associations were observed in most genetic models.

CONCLUSIONS

This meta-analysis suggests that the MDM2 309 G allele probably acts as an important HCC risk factor. To further confirm our findings, well-designed studies with large sample sizes and representing different ethnicities are required.

hSSB1 binds and protects p21 from ubiquitin-mediated degradation and positively correlates with p21 in human hepatocellular carcinomas

Downregulation of hSSB1, a single-stranded DNA-binding protein, causes increased radiosensitivity, defective checkpoint activation and genomic instability. However, the mechanisms of hSSB1 function in these responses remain to be uncovered. Here, we present evidence that hSSB1 directly binds p21 and this interaction may prevent p21 from ubiquitin-mediated degradation. Furthermore, both promotion of the G1/S transition and abrogation of the G2/M checkpoints induced by hSSB1 knockdown are partially dependent on p21. Most importantly, hSSB1 and p21 levels are positively correlated in human hepatocellular carcinomas (HCC), as determined by immunostaining. Therefore, hSSB1 may positively modulate p21 to regulate cell cycle progression and DNA damage response, implicating hSSB1 as a novel, promising therapeutic target for cancers such as HCC.

Correlation between clinical characteristics, survival and genetic alterations in patients with hepatocellular carcinoma from Saudi Arabia

Amplification of the two oncogenes ERBB2 and MYC and deletion of the tumor suppressor gene TP53 are frequently encountered in cancerous tissues. The purpose of this study was to use the fluorescence in situ hybridization (FISH) technique for the assessment of ERBB2 and MYC amplification and TP53 deletion, and to relate these molecular markers to clinical and pathologic factors in Saudi patients with hepatocellular carcinoma. The study was conducted on 40 paraffin-embedded tissue samples originally taken from either hepatitis C virus (HCV)- or HBV-infected patients using the FISH technique. The level of ERBB2, MYC, and TP53 in the malignant group was significantly increased as compared to the control group. Of the 40 patients, 3 (7.5%) had amplification of ERBB2 gene, 4 (10%) different patients had amplification of MYC, and 26 patients (65%) had evidence of deletion of at least one allele on chromosome 17 for the TP53 gene in a high proportion of cells. There was a significant correlation between amplification of MYC oncogene and the number of tumor masses. Moreover, significant correlation was observed between poorly differentiated tumors when compared with moderate or well-differentiated tumors when MYC was analyzed. On the other hand, MYC failed to reveal any significant association between oncogene amplification and other clinicopathologic variables examined. Univariate analysis revealed a strong association between deletion of TP53 and multiple tumor mass (P< 0.001). No statistical correlation could be detected between deletion of TP53 and tumor size, grade, stage, and tumor differentiation. No significant difference could be detected in the mean survival time of patients positive for the alteration of the genes compared to the patients who showed no alterations for the same genes. However, when the stage of the tumor was analyzed, there was a significant difference in the mean survival time between patients who showed gene alterations compared to patients with no changes in the studied genes. When overall survival was analyzed, only patients with MYC amplification had a lower median survival (20.75 months) than patients without MYC amplification (35.82, P = 0.009). Genetic alterations of ERBB2 and TP53 genes had no effect on survival 2 (see Results). The combination of ERBB2, MYC, and TP53 could be useful markers to stratify patients into different risk groups.

Correlation between expression of p53, p21/WAF1, and MDM2 proteins and their prognostic significance in primary hepatocellular carcinoma

Background

Tumor Protein p53 (p53), cyclin-dependent kinase inhibitor 1A (p21/WAF1), and murine double minute 2 (MDM2) participate in the regulation of cell growth. Altered expression of these gene products has been found in malignant tumors and has been associated with poor prognosis. Our aim was to investigate the expression of the 3 proteins in hepatocellular carcinoma (HCC) and their prognostic significance.

Methods

We examined p53, p21/WAF1, and MDM2 expression in 181 pairs of HCC tissues and the adjacent hepatic tissues by performing immunohistochemistry and examined the expression of the 3 proteins in 7 pairs of HCC tissues and the adjacent hepatic tissues by using western blot analysis.

Results

The expression of p53, p21/WAF1, and MDM2 in the HCC tissues was significantly higher than those in the adjacent hepatic tissues (P < 0.05). A statistical correlation was observed between p53 and p21/WAF1 expression in HCC tissues (R = 0.195, P = 0.008). A statistical correlation was observed between expression of p53 and p21/WAF1 (R = 0.380, P = 0.000), p53 and MDM2 (R = 0.299, P = 0.000), p21/WAF1 and MDM2 (R = 0.285, P = 0.000) in 181 liver tissues adjacent to the tumor. Patients with a low pathologic grade HCC (I+II) had a higher tendency to express p53 on tumor cells than the patients with high pathologic grade HCC (III+IV) (P = 0.007). Survival analysis showed that positive p21/WAF1 expression or/and negative MDM2 expression in HCC was a predictor of better survival of patients after tumor resection (P < 0.05).

Conclusions

The proteins p53, p21/WAF1, and MDM2 were overexpressed in all the HCC cases in this study, and p53 and p21/WAF1 overexpression were positively correlated. The expression of p21/WAF1 and MDM2 can be considered as 2 useful indicators for predicting the prognosis of HCC.

Association between MDM2-SNP309 and hepatocellular carcinoma in Taiwanese population

AIM: To investigate the risk association and compare the onset age of hepatocellular carcinoma (HCC) patients in Taiwan with different genotypes of MDM2-SNP309.

METHODS: We analyzed MDM2-SNP309 genotypes from 58 patients with HCC and 138 cancer-free healthy controls consecutively. Genotyping of MDM2-SNP309 was conducted by restriction fragment length polymorphism assay.

RESULTS: The proportion of homozygous MDM2-SNP309 genotype (G/G) in cases and cancer-free healthy controls was similar (17.2% vs 16.7%). Multivariate analysis showed that the risk of G/G genotype of MDM2-SNP309 vs wild-type T/T genotype in patients with HCC was not significant (OR = 1.265, 95% CI = 0.074-21.77) after adjustment for sex, hepatitis B or C virus infection, age, and cardiovascular disease/diabetes. Nevertheless, there was a trend that GG genotype of MDM2-SNP309 might increase the risk in HCC patients infected with hepatitis virus (OR = 2.568, 95% CI = 0.054-121.69). Besides, the homozygous MDM2-SNP309 genotype did not exhibit a significantly earlier age of onset for HCC.

CONCLUSION: Current data suggest that the association between MDM2-SNP309 GG genotype and HCC is not significant, while the risk may be enhanced in patients infected by hepatitis virus in Taiwan.

Tetraspanin CD81-regulated cell motility plays a critical role in intrahepatic metastasis of hepatocellular carcinoma

BACKGROUND & AIMS

Human hepatocellular carcinoma (HCC) can invade the portal vein and metastasize to other parts of the liver. Currently, the molecular and cellular mechanisms underlying intrahepatic metastasis of HCC are poorly understood. Tumor invasiveness could be considered an aspect of dysregulated motility, and the mechanisms that inhibit cell movement are considered to counteract the spreading of cancer cells through the liver. Accumulating observations suggest that the CD81 tetraspanin may have an inhibitory effect on cell movement.

METHODS

In the present study using both loss- and gain-of-gene function approaches, we verified that the functional interaction of tetraspanin CD81 with type II phosphoinositide 4-kinase (PI4KII) suppressed HCC cell motility by promoting the formation of CD81-enriched vesicles, non-endosomal intracellular structures, that sequestered actinin-4 with consequent remodeling of actin cytoskeleton.

RESULTS

We reported that HCC cells expressing CD81 showed an inability to metastasize compared with HCC cells with undetectable levels of CD81.

CONCLUSIONS

Taken together, these findings indicate that CD81 functions as a molecular organizer of membrane microdomains, whereby proteins such as PI4KII control actin remodeling and cell motility, establishing a role for these genes as negative modifiers of oncogenicity and HCC progression.

Changes in genomic imprinting and gene expression associated with transformation in a model of human osteosarcoma

Genomic imprinting, a heritable form of epigenetic information, is thought to play an important role in tumor progression. DNA methylation is a common mechanism of genomic imprinting. To evaluate the genome-wide effects of malignant transformation on osteosarcoma progression, we examined multiple biological properties, including DNA methylation, in human osteoblast hFOB1.19 cells (ATCC Catalog No. CRL-11372) transformed by treatment with carcinogenic agent N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG, 1.0 microg/ml) and carcinogenic promoting agent 12-O-tetradecanoyl phorbol-13-acetate (TPA, 200 ng/ml). We also examined global changes in expression of imprinted genes during transformation using microarray analysis. Ten imprinted genes, including H19, MKRN3, NDN, CDKN1C, PHLDA2, MEST, CD81, GRB10, SLC22A18, and SLC22A3 were aberrantly regulated in transformed cells, suggesting roles in tumorigenesis. Moreover, we analyzed the methylation state of the promoter regions of H19, PHLDA2, and SLC22A18 genes by bisulfite sequencing array and observed a correlation between upregulated expression of H19 and PHLDA2 genes and hypomethylation of their promoter regions, although this was not observed for SLC22A18. Our results suggest that changes in expression of imprinted genes caused by changes in methylation are involved, and are among the earliest events, in neoplastic progression.

Failure of Lamivudine to Reverse Hepatitis B Virus-Associated Changes in ERK, Akt and Cell Cycle Regulatory Proteins

Background

Chronic infection with hepatitis B virus (HBV) is a major factor associated with the development of hepatocellular carcinoma, but the mechanism by which this occurs is unknown. Treatment of chronic hepatitis B with lamivudine results in virological suppression and histological improvement; however, the role of lamivudine in preventing the development of hepatocellular carcinoma is less well defined. We recently reported that replication of HBV in a cell-culture system was associated with the upregulation of pERK, pAkt, pc-Myc, nuclear cyclin B1, p21cip1 and p53 together with G2 cell cycle arrest.

Methods

In order to determine whether lamivudine is able to reverse the HBV-induced changes on signal transduction and cell cycle, we infected Huh7 cells with a recombinant adeno-HBV virus in the presence of 0–50 μM of lamivudine. Signal transduction and cell cycle regulatory proteins were analysed by western immunoblot.

Results

Although lamivudine was able to inhibit HBV replication, it failed to reverse the changes on ERK and Akt phosphorylation. Correspondingly, levels of phospho-GSK3β and p21cip1/waf1 were increased, as were cyclin D1, cyclin B1, p53 and pc-Myc.

Conclusions

Lamivudine was ineffective in reversing the HBV-induced changes in signal transduction pathways and cell cycle regulatory proteins, indicating that the HBV-infected cells remained primed for oncogenic transformation despite viral suppression.

Phase I study of individualized stereotactic body radiotherapy for hepatocellular carcinoma and intrahepatic cholangiocarcinoma

PURPOSE

To report outcomes of a phase I study of individualized stereotactic body radiotherapy treatment (SBRT) for unresectable hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC).

PATIENTS AND METHODS

Patients with unresectable HCC or IHC, and who are not suitable for standard therapies, were eligible for six-fraction SBRT during 2 weeks. Radiation dose was dependent on the volume of liver irradiated and the estimated risk of liver toxicity based on a normal tissue complication model. Toxicity risk was escalated from 5% to 10% and 20%, within three liver volume-irradiated strata, provided at least three patients were without toxicity at 3 months after SBRT.

RESULTS

Forty-one patients with unresectable Child-Pugh A HCC (n = 31) or IHC (n = 10) completed six-fraction SBRT. Five patients (12%) had grade 3 liver enzymes at baseline. The median tumor size was 173 mL (9 to 1,913 mL). The median dose was 36.0 Gy (24.0 to 54.0 Gy). No radiation-induced liver disease or treatment-related grade 4/5 toxicity was seen within 3 months after SBRT. Grade 3 liver enzymes were seen in five patients (12%). Two patients (5%) with IHC developed transient biliary obstruction after the first few fractions. Seven patients (five HCC, two IHC) had decline in liver function from Child-Pugh class A to B within 3 months after SBRT. Median survival of HCC and IHC patients was 11.7 months (95% CI, 9.2 to 21.6 months) and 15.0 months (95% CI, 6.5 to 29.0 months), respectively.

CONCLUSION

Individualized six-fraction SBRT is a safe treatment for unresectable HCC and IHC.

P21/WAF1 is an independent survival prognostic factor for patients with hepatocellular carcinoma after resection

BACKGROUND/AIMS

The cyclin kinase inhibitor p21/WAF1 is regulated by p53-dependent or independent pathways and inhibits the action of proliferating cell nuclear antigen (PCNA). The prognostic role of p21/WAF1 in hepatocellular carcinoma (HCC) is ambiguous. To further clarify this, we examined the expression of three genes in HCC.

METHODS

A total of 122 resected HCC specimens were collected from 1987 to 1998. Expression of p21/WAF1, p53, and PCNA in HCC was analysed by immunohistochemistry.

RESULTS

Immunoreactivity was detectable for p21/WAF1 in 37%, and for p53 in 41.8% of HCCs. Positive expression of both genes does not relate to each other, but both are associated with a high PCNA labelling index (LI) (P<0.05) in tumour. p53 (+) is also associated with high serum alpha-foetoprotein (alphaFP) (P<0.001), tumour dedifferentiation (P=0.001) and advanced pathologic stages (P=0.017). However, p21/WAF1 (+) did not show clinicopathologic significance. Survival analysis indicated that poor prognostic factors were p21/WAF1 (-) (P=0.024), p53 (+) (P=0.008), high PCNA (P<0.001), tumour without capsule (P=0.001), poor tumour differentiation (P=0.004), advanced pathologic stage (P<0.001), and high serum alphaFP(P<0.001). Independent factors were p21/WAF1 expression, pathologic stage, and PCNA.

CONCLUSION

In HCC, increased proliferation index PCNA is significantly associated with positive p53 and p21/WAF1. But p21/WAF1 expression did not relate to p53 expression. P21/WAF1 (+) is a good event and serves as an independent survival prognostic factor for HCC, which is a novel finding apart from previous reports.

Proline-Directed Protein Kinase FAIs a Powerful and Independent Prognostic Predictor for Progression and Patient Survival of Hepatocellular Carcinoma

Purpose

Molecular, cellular, and animal studies have established that overexpressed proline-directed protein kinase FA(PDPK FA) is essential for the development of tumorigenesis, invasion, and metastasis of human cancer cells. However, the prognostic role of PDPK FAin cancer patients remains largely unknown. In this study, association of PDPK FAexpression with poor prognosis of hepatocellular carcinoma (HCC) patients was examined.

Patients and Methods

PDPK FAexpression in the resected tumors of 134 HCC patients (112 men and 22 women) with ages ranging from 33 to 83 years (mean, 55 years) was analyzed by immunohistochemistry. Highly condensed cytoplasmic and nuclear PDPK FAassociated with tumor cells was used as the major scoring parameter for positive PDPK FAexpression.

Results

Approximately 68% of the patients (91 of 134) exhibited positive PDPK FAexpression. Patients with positive PDPK FAshowed poorer disease-free survival and overall survival (P < .001). Cox multivariate regression analysis further established PDPK FAas the strongest independent prognosticator for progression and patient survival of HCC (hazard ratio [HR], 2.878; 95% CI, 1.634 to 5.067 for disease-free survival; and HR, 5.035; 95% CI, 2.137 to 11.866 for overall survival; P < .001).

Conclusion

Consistent with PDPK FA’s essential role in the development of highly malignant phenotypes, the present study establishes the potential prognostic role of PDPK FAin progression and patient survival of surgically resected primary HCC. Taken together, PDPK FArepresents a new modifiable signal-transducing target for prognostic prediction and adjuvant treatment of patients with aggressive HCC after hepatic resection.

Serum tumor markers for detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors and is the second most common cause of cancer death in China. Therefore, it is very important to detect this disease and the recurrence at its earlier period. Serum tumor markers, as the effective method for detecting hepatocellular carcinoma for a long time, could be divided into 4 categories: oncofetal antigens and glycoprotein antigens; enzymes and isoenzymes; genes; and cytokines. Serum alpha fetoprotein (AFP) is the most widely used tumor marker in detecting patients with hepatocellular carcinoma, and has been proven to have capability of prefiguring the prognosis. However, it has been indicated that AFP-L3 and DCP excel AFP in differentiating hepatocellular carcinoma from nonmalignant hepatopathy and detecting small hepatocellular carcinoma. Some tumor markers, such as human cervical cancer oncogene and human telomerase reverse transcriptase mRNA, have also been indicated to have higher accuracies than AFP. Furthermore, some other tumor markers, such as glypican-3, gamma-glutamyl transferase II, alpha-l-fucosidase, transforming growth factor-beta1, tumor-specific growth factor, have been indicated to be available supplementaries to AFP in the detection. AFP mRNA has been shown to correlate with the metastasis and recurrence of HCC, and it may be the most useful marker to prefigure the prognosis. Some other markers, such as gamma-glutamyl transferase mRNA, vascular endothelial growth factor, and interleukin-8, could also be used as available prognostic indicators, and the simultaneous determination of AFP and these markers may detect the recurrence of HCC at its earlier period.

Immunohistochemical Detection of Mdm2 and p53 in Feline Mammary Gland Tumors

The objective of this study was to evaluate nuclear reactivity of Mdm2 and p53 proteins by immunohistochemical means in feline mammary gland tumors; 12 adenomas which included 6 adenomatous lesions obtained from the tissue adjacent to adenocarcinomas, and 22 adenocarcinomas. Seven adenomas and 18 adenocarcinomas showed moderate or marked Mdm2 reactivity. Sixteen adenocarcinomas showed moderate to marked p53 reactivity, but 9 adenomas showed none. Discordant Mdm2 overexpression was found in 5 adenomas and 3 adenocarcinomas, although co-overexpression of Mdm2 and p53 was found in 15 adenocarcinomas. These results suggest that nuclear overexpression of Mdm2 is present in the tumors of early stage without p53 overexpression and related to feline mammary gland tumorigenesis. Nuclear overexpression of p53 is more frequent in adenocarcinomas, but not in adenomas.