Hepatic stem cells and transforming growth factor β in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and lethal cancers worldwide. It arises from modulation of multiple genes by mutations, epigenetic regulation, noncoding RNAs and translational modifications of encoded proteins. Although >40% of HCCs are clonal and thought to arise from cancer stem cells (CSCs), the precise identification and mechanisms of CSC formation remain poorly understood. A functional role of transforming growth factor (TGF)-β signalling in liver and intestinal stem cell niches has been demonstrated through mouse genetics. These studies demonstrate that loss of TGF-β signalling yields a phenotype similar to a human CSC disorder, Beckwith-Wiedemann syndrome. Insights into this powerful pathway will be vital for developing new therapeutics in cancer. Current clinical approaches are aimed at establishing novel cancer drugs that target activated pathways when the TGF-β tumour suppressor pathway is lost, and TGF-β itself could potentially be targeted in metastases. Studies delineating key functional pathways in HCC and CSC formation could be important in preventing this disease and could lead to simple treatment strategies; for example, use of vitamin D might be effective when the TGF-β pathway is lost or when wnt signalling is activated.     

Systemic chemotherapy for hepatocellular carcinoma in non-cirrhotic liver： A retrospective study

AIM： To investigate the efficacy and toxicity of systemic chemotherapy in a retrospective study of patients with hepatocellular carcinoma （HCC） occurring in normal or fibrotic liver without cirrhosis.
METHODS： Twenty-four patients with metastatic or locally advanced HCC in a normal or a fibrotic liver were given systemic chemotherapy （epirubicin, cisplatin and 5-fluorouracil or epirubicin, cisplatin and capecitabine regimens）. Tumor response, time to progression, survival, and toxicity were evaluated.
RESULTS： There were 7 women and 17 men, mean age 54 ± 10 years; 18 patients had a normal liver and 6 had a fibrotic liver （F1/F2 on biopsy）. Mean tumor size was 14 cm, 5 patients had portal vein thrombosis and 7 had metastasis. Patients received a median of 4 chemotherapy sessions. Overall tolerance was good. There were 5 partial responses （objective response rate = 22%）, and tumor control rate was 52%. Second line surgical resection was possible in two patients. Median survival was 11 mo, and 1- and 2-year overall survival rates were 50% ± 10% and 32 ± 11%, respectively.
CONCLUSION： In patients with HCC in a non-cirrhotic liver, chemotherapy was well tolerated and associated with an objective response rate of 22%, including two patients who underwent secondary surgical resection.     

Transforming growth factor-β1 gene expression in hepatocellular carcinoma: A preliminary report

Background and study aimsThe transforming growth factor (TGF)-β signalling pathway plays a dual role in hepatocarcinogenesis. It has been recognised for its role as a tumour suppressor as well as a tumour promoter depending on the cellular context.The aim of this study was to investigate the clinical significance of serum TGF-β1 level and TGF-β1 messenger RNA (mRNA) in the peripheral blood of liver cirrhosis and hepatocellular carcinoma (HCC) patients as noninvasive biomarkers in diagnosing HCC.Patients and methodsTwenty patients were allocated to each of the liver cirrhosis and HCC groups, in addition to 20 healthy volunteers. TGF-β1 gene expression in peripheral blood was quantitated using real-time polymerase chain reaction (PCR), while serum TGF-β1 was analysed using enzyme-linked immunosorbent assay (ELISA).ResultsTGF-β1 gene expression was significantly lower in HCC patients (median 0.401 (0.241–0.699) fold change) than in liver cirrhosis patients (median 0.595 (0.464–0.816)) (p = 0.042) and normal controls (median 1.00 (0.706–1.426) fold change) (p = 0.001). TGF-β1 gene expression showed significant positive correlation with serum TGF-β1 (r = 0.272, p = 0.036) and significant negative correlation with alpha-fetoprotein (AFP) (r = −0.528, p = 0.001). Receiver operating characteristic (ROC) analysis was conducted for TGF-β1 gene expression in comparison with AFP. The area under the curve for TGF-β1 gene expression was 0.688 (95% CI = 0.517–0.858) (p = 0.042) and AFP was 0.869 (95% CI = 0.761–0.976) (p = 0.001). The sensitivity and specificity of TGF-β1 gene expression were 65% and 75%, respectively, at a cutoff value of 0.462 fold change.ConclusionTGF-β1 gene expression in the peripheral blood may be used as a molecular marker for the diagnosis of HCC. Additional studies on a large-scale population are necessary to gain greater insight into the impact of TGF-β1 gene expression in the pathogenesis of HCC.     

α-Fetoprotein,tissue polypeptide antigen and ferritin in diagnosing primary hepatocellular carcinoma in patients with liver cirrhosis

Summary This study was undertaken in order to compare the usefulness of three indices of tumour proliferation in detecting primary hepatocellular carcinoma (HCC) and in differentiating this neoplasm from liver cirrhosis. In 10 patients with HCC and in 63 with liver cirrhosis serum -fetoprotein (AFP), tissue polypeptide antigen (TPA) and ferritin were assayed. Increased levels of AFP but not of TPA and ferritin were observed in HCC as compared to liver cirrhosis. The receiver-operating characteristic curves demonstrated that AFP is more discriminating between HCC and liver cirrhosis than the other two markers. Correlations between liver function tests and serum markers were observed in liver cirrhosis but not in HCC. We can conclude that AFP is more useful than TPA and ferritin in detecting HCC in patients with liver cirrhosis, owing to the high frequency of false positive results of the latter two indices in liver cirrhosis. Liver dysfunction is probably involved in increasing all these markers of malignancy, thus reducing the specificity of these tests.Abbreviations AFP -tetoprotein - TPA tissue polypeptide antigen - HCC primary hepatocellular carcinoma Partially supported by a grant of the Italian National Research Council, Special Project Oncology, contract 87.01.541.04. Under the auspices of the R. Farini association for gastroenterological research     

Activation of c-Yes in hepatocellular carcinoma: A preliminary study

TO THE EDITOR Hepatocellular carcinoma (HCC) is thought to develop through a multistep process[1]. A long history of viralhepatitis or prolonged exposure to environmental toxins predisposes liver cells to mutations of the genes critical in the control of hepatocyte growth. In fact, both activa- tion of cellular oncogenes and inactivation of tumor- suppressor genes are involved in the development of HCC. Activation of oncogenes by hepatitis virus integra- tion has been shown in the woodc…     

Activation of c-Yes in hepatocellular carcinoma： A preliminary study

TO THE EDITOR Hepatocellular carcinoma (HCC) is thought to develop through a multistep process[1]. A long history of viral hepatitis or prolonged exposure to environmental toxins predisposes liver cells to mutations of the genes critical in the control of hepatocyte growth. In fact, both activation of cellular oncogenes and inactivation of tumorsuppressor genes are involved in the development of HCC. Activation of oncogenes by hepatitis virus integration has been shown in the woodchuck animal model[2],although the significance of this finding in human hepatocarcinogenesis is still under investigation.     

Fibroblast growth factor 2 and transforming growth factor β1 interactions in human liver myofibroblasts

During liver fibrogenesis, myofibroblastic liver cells proliferate and synthesize components of fibrosis. Fibroblast growth factor 2 (FGF-2) is expressed in vivo in myofibroblastic liver cells (MFLCs) during fibrogenesis, and exogenous FGF-2 is mitogenic for MFLCs. The aim of this study was to study the expression and role of endogenous FGF-2 in cultured human MFLCs. FGF-2 and FGF-2 receptors were studied using immunoblotting. All RNA studies used ribonuclease protection. Growth of MFLCs was studied using [³H]thymidine incorporation and direct cell counting. MFLCs expressed FGF-2 and its receptors FGF receptor 1 and FGF receptor 2. An antibody to FGF-2 blocked the mitogenic effect of transforming growth factor β1 (TGF-β1) for MFLCs but not TGF-β1-induced increase in cellular fibronectin messenger RNA (mRNA). TGF-β1 increased levels of FGF-2 and FGF receptor mRNAs in MFLCs. We have previously shown that TGF-β1 also increased platelet-derived growth factor (PDGF) A chain mRNA in these cells and that anti-PDGF antibody blunted the mitogenic effect of TGF-β1. The present results show that anti-FGF-2 and anti-PDGF-AA are not additive and that FGF-2 and PDGF-AA are not sequentially induced by TGF-β1. FGF-2 mediates the mitogenic but not the profibrogenic effect of TGF-β1 for human MFLCs, and autocrine FGF-2 and PDGF-A interact in the mediation of the mitogenic effect of TGF-β1.     

Transforming growth factor-β1 regulates platelet-derived growth factor receptor β subunit in human liver fat-storing cells

Activated liver fat-storing cells (FSC) are known to play a key role in the development of liver fibrosis. An important element in FSC activation process is the increased expression of receptors for platelet-derived growth factor (PDGF), a potent mitogen for FSC. The aim of the present study was to evaluate the expression PDGF-receptor alpha and beta subunits in cultured human FSC and their regulation induced by transforming growth factor-β1 (TGF-β), a cytokine potentially involved in an autocrine loop. TGF-β induced a significant increase of the mitogenic effect of PDGF-BB and did not affect the mitogenicity of PDGF-AA and PDGF-AB, suggesting a selective action of the PDGF-receptor-β subunit. This hypothesis was confirmed by regulation experiments showing selective and time-dependent upregulation of the messenger (m)RNA encoding for the PDGF-receptor-β subunit and the relative protein induced by TGF-β. In addition, binding studies showed a parallel increase of PDGF-BB binding sites after incubation of human FSC with TGF-β. These studies provide evidence for an additional mechanism leading to the perpetuation of FSC activation and proliferation and contribute to a better understanding of the role of TGF-β and PDGF in the development of liver fibrosis.     

Transforming growth factor—β1in invasion and metastasis in colorectal cancer

AIM：To investigate the role of TGFβ1 in invasion and metastasis in colorectal cancer by analysing TGFβ1 correlated wity depth of tumor invasion,stage and metastasis.METHODS:Serum TGFβ1levels were determined in50patients with colorectal cancer and 30healthy volunteers using a TGFβ1 enzyme-linked immunosorbent assay.TGFβ1 expression in primary and lymph node metastatic lesions were detected in 98cases of colorectal cancer by immunohistochemical staining and in situ hybridization.RESULTS:Serum levels of TGFβ1 in patients with colorectal cancer(40±18μg·L^-1)were significantly higher than those in the healthy control group(19±8μg·L^-1),P<0.05.Elevated levels of serum TGFβ1were found in 60%of patients with colorectal cancer when the mean+2s was used as the upper limit of the normal range(35.1μg·L^-1).Increases in serum TGFβ1 levels were significantly asociated with Dukei‘s stage(P<0.05),but there was no significant difference between,Duki‘s stage Bpatients and Dukei‘s stage Cpatients.In the cytoplasm of cancer cells,TGFβ1 was immunostained in37.8%(37/98)of colorectal cancer,and this expression was confirmed by in situ hybridization,Among35cases of colorectal cancer with lymph node metastatic lesions,TGFβ1 positive staining was found in18(51.4%)cases of primary tumor,and 25(71.4%)cases with lymph node metastatic lesions,respectively,Of17cases with no staining in the primary lesion.7(41.2%)casesshowed TGFβ1 staining in the metastatic lesion.Serum TGFβ1 levels and TGFβ1 expression in colorectal cancer tissues were correlated significantly with depth of tumor invasion,stage and metastasis,Patients in stage C-D,T3-T4and with metastasis had significantly higher TGFβ1 levels than patients in stage A-B,T1-T2and without metastasis(P<0.05).CONCLUSION:These results suggest that transforming growth factor-β1 is closely related to the invasion and metastasis of colorectal cancer.It increased the invasive and metastatic potential of tumor by altering a tumor microenvironment.TGFβ1 may be used as a possible biomarke.     

Association between the presence of H pylori in the liver and hepatocellular carcinoma： A meta-analysis

AIM： To evaluate the arguments for and against the possible roles of H pylori in hepatocellular carcinoma （HCC）.
METHODS： We performed a systematic review of all relevant studies published in the literature. A total of 103 clinical trials and reports were identified, but only 10 trials qualified under our selection criteria. A metaanalysis was carried out by a biostatistician according to the Cochrane Reviewers＇ Handbook recommended by The Cochrane Collaboration.
RESULTS： Nine case-control studies and one retrospective cross sectional study were included in the final analysis. Overall the prevalence of H pylori infection was 53.3% （129 of 242） in cases and 10.4% （29 of 280） in controls, and the summary odds ratio for the association of H pylori infection with the risk for HCC （using the fixed-effects model, which accounted for the homogeneity across the 10 studies） was determined to be 13.63 （95% CI, 7.90-23.49）.
CONCLUSION： Our analysis showed a positive association between F1 pylori infection and the risk of HCC, with an indication of possible publication bias and possible confounders due to study designs that showed results of less pronounced associations.     

Serum ferritin and the risk of hepatocellular carcinoma in chronic liver disease of viral etiology: A case–control study

Background

The worldwide incidence rates of hepatocellular carcinoma (HCC) vary widely. Some countries like India have a low incidence despite having a large burden of chronic hepatitis B (HBV) and C virus (HCV) infection. We hypothesized that long-term iron deficiency could attenuate the hepatic inflammation and lead to a lower incidence of HCC in India than expected.

Methods

We evaluated the association of serum ferritin levels and HCC in Indian patients with HBV- or HCV-related chronic liver disease (CLD) using a case–control study design. We enrolled 141 patients with HCC (cases) and 240 patients having chronic HBV or HCV infection-related CLD (controls). Study participants were grouped on the basis of ferritin values into low-normal, high-normal, and high subgroups.

Results

Mean ferritin values were higher in cases as compared to controls (425.8 vs. 135.6 ng/mL, p?=?0.000). A significant dose–response effect for serum ferritin levels and HCC was seen with an odds ratio (95 % confidence interval) of 3.0 (1.6–5.9, p?=?0.001) for subjects with high-normal ferritin levels and 8.2 (4.1–16.5, p?=?0.000) for subjects with high ferritin levels in a multivariate model. Other significant independent risk factors in the multivariate model included older age, male gender, alcohol and tobacco use, elevated alanine aminotransferase, higher family income, and coffee drinking.

Conclusion

We found an independent association between serum ferritin levels and HCC in patients with CLD of viral etiology. Further prospective studies are needed to confirm the hypothesis that iron deficiency protects against HCC in CLD.