Expression of transforming growth factor beta-1 in chronic hepatitis and hepatocellular carcinoma associated with hepatitis C virus infection

Transforming Growth Factor Β as a Marker of Hepatocellular Carcinoma in Patients with Chronic Hepatitis C Virus Infection

Background

The Transforming Growth Factor-beta (TGF-β) is one of the main growth factors associated with fibrosis or cirrhosis progression in the liver, but its role in hepatocarcinogenesis is controversial. To highlight the role of Transforming Growth Factor β as a marker of Hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus (HCV) infection.

Methods

Ninety subjects were enrolled in this study, classified into three groups: Group I (chronic HCV group) included 30 patients with chronic HCV infection; Group II (HCC group) include 30 patients having HCC and chronic HCV infection and Group III consisted of 30 age and sex-matched healthy controls. TGF-β was evaluated in all the enrollees and its levels were correlated to liver function and other clinical parameters.

Results

TGF-β was found significantly higher in HCC group than in control and chronic HCV (P<0.001). In addition, it was correlated with biochemical and clinical parameters of cancer.

Conclusion

Patients with HCC showed increased level of TGF-β compared to chronic HCV infection patients and controls.

Induction of tolerogenic dendritic cells by activated TGF-β/Akt/Smad2 signaling in RIG-I-deficient stemness-high human liver cancer cells

BACKGROUND

Dendritic cells (DCs) alter their role from being immunostimulatory to immunosuppressive at advanced stages of tumor progression, but the influence of cancer stem cells (CSCs) and their secreted factors on generation and phenotypic change of DCs is unknown. Retinoic acid-inducible gene I (RIG-I) plays a role in regulation of other cellular processes including leukemic stemness besides its antiviral function.

METHODS

Short hairpin RNA-mediated gene silencing was employed to generate stable RIG-I-knocked-down human hepatocellular carcinoma (HCC) cell lines. Expression levels of genes and proteins in spheres of those HCC cells were determined by quantitative real-time PCR and Western bot, respectively. Levels of secreted cytokines were measured by ELISA. The surface molecule expression levels of DCs were analyzed using flow cytometry. The ability of DCs to induce proliferation of T cells was assessed by a mixed lymphocyte reaction (MLR) assay.

RESULTS

RIG-I-knocked-down HCC cells showed upregulated expression of stem cell marker genes, enhanced secretion of factors suppressing in vitro generation of DCs into the conditioned medium (CM), and induction of a phenotype of tumor-infiltrating DCs (TIDCs) with low levels of DC markers in their tumors in nude mice. Those DCs and TIDCs showed reduced MLR, indicating RIG-I deficiency-induced immunotolerance. The RIG-I-deficient HCC cells secreted more TGF-β1 than did reference cells. The tumors formed after injection of RIG-I-deficient HCC cells had higher TGF-β1 contents than did tumors derived from control cells. DC generation and MLR suppressed by the CM of RIG-I-deficient HCC cells were restored by an anti-TGF-β1 antibody. TGF-β1-induced phosphorylation of Smad2 and Akt was enhanced in RIG-I-deficient HCC spheres, knockdown of AKT gene expression abolishing the augmentation of TGF-β1-induced Smad2 phosphorylation. Akt and p-Akt were co-immunoprecipitated with Smad2 in cytoplasmic proteins of RIG-I-deficient spheres but not in those of control spheres, the amounts of co-immunoprecipitated Akt and p-Akt being increased by TGF-β stimulation.

CONCLUSIONS

Our results demonstrate that RIG-I deficiency in HCC cells induced their stemness, enhanced secretion and signaling of TGF-β1, tolerogenic TIDCs and less generation of DCs, and the results suggest involvement of TGF-β1 in those RIG-I deficiency-induced tolerogenic changes and involvement of CSCs in DC-mediated immunotolerance.

Targeting cancer stem cells by using the nanoparticles

Cancer stem cells (CSCs) have been shown to be markedly resistant to conventional cancer treatments such as chemotherapy and radiation therapy. Therefore, therapeutic strategies that selectively target CSCs will ultimately lead to better cancer treatments. Currently, accessible conventional therapeutic agents mainly eliminate the bulk tumor but do not eliminate CSCs. Therefore, the discovery and improvement of CSC-targeting therapeutic agents are necessary. Nanoparticles effectively inhibit multiple types of CSCs by targeting specific signaling pathways (Wnt/β-catenin, Notch, transforming growth factor-β, and hedgehog signaling) and/or specific markers (aldehyde dehydrogenases, CD44, CD90, and CD133) critically involved in CSC function and maintenance. In this review article, we summarized a number of findings to provide current information about their therapeutic potential of nanoparticles in various cancer cell types and CSCs.

Overexpression of cyclooxygenase-2 and transforming growth factor-beta 1 is an independent predictor of poor virological response to interferon therapy in chronic HCV genotype 4 patients

BACKGROUND/AIMS

COX-2 and TGF-β1 are overexpressed in hepatitis C virus (HCV) infection and are related to hepatitis pathogenesis and hepatic fibrosis. The current study investigated the relationship between pretreatment COX-2 and TGF-β1 hepatic expression in HCV genotype 4 and the virological response to interferon therapy.

PATIENTS AND METHODS

Liver biopsies of 55 patients with HCV infection genotype 4 were selected together with 10 liver biopsies as control. The patients' clinicopathological data were collected. Immunohistochemistry was done using anti-COX-2 and anti-TGF-β1 antibodies. Statistical tests were used to determine the association between both COX-2 and TGF-β1 expression in relation to clinicopathological parameters and response to interferon therapy.

RESULTS

COX-2 was upregulated especially in nonresponders and was an independent predictor of poor virological response. However, COX-2 showed no association with other clinicopathological features. TGF-β1 was upregulated and associated with nonresponders, histological activity, and fibrosis stage. There was no association between TGF-β1 and other clinicopathological features. There was an association between COX-2 and TGF-β1 immunoexpression.

CONCLUSION

Overexpression of COX-2 and TGF-β1 is an independent predictor for poor outcome of interferon and ribavirin therapy and these might be useful markers for the response to treatment. Both molecules are associated together; however, their role during hepatitis treatment has to be clarified.

MAGE-4 gene m-RNA and TGF in blood as potential biochemical markers for HCC in HCV-infected patients

Progression from chronic hepatitis C virus infection to cirrhosis then to hepatocellular carcinoma usually results in some protein changes in peripheral blood. We evaluated MAGE-4 mRNA, TGFβ1 and AFP in peripheral blood as potential biochemical markers for diagnosis and prognosis of some complications of HCV infection. MAGE-4 mRNA in blood by reverse transcription polymerase chain reaction, serum TGF-Β1 and AFP by ELISA was assayed in seventy-five individuals who were classified into five groups: group I (control) comprised fifteen apparently healthy volunteers, group II involved fifteen HCV-infected patients without cirrhosis, group III involved fifteen HCV fifteen HCV-infected patients with cirrhosis, group IV included fifteen HCV-infected patients with cirrhosis and early stage HCC, and group V included fifteen HCV cirrhotic patients and late-stage HCC. We found that the frequency of positivity of MAGE-4 among the late hepatoma group was 40 %, while in the early hepatoma group the positivity was 6.7 %. The results for TGF-Β1 revealed a significant increase in serum TGF-Β1 in groups IV and V as compared to control, II, III groups. The obtained results of AFP showed a significant positive increase in serum AFP in groups IV and V when compared to groups II and III. Detection of MAGE-4 transcripts in blood, especially with follow-up survey, may help to predict the prognosis and monitoring of the response to the therapy, and serum TGF-Β1 level in HCC patients is directly correlated with metastasis and recurrence of tumors and increases gradually with the progression of HCC.

Hepatitis C virus-host interactions: Etiopathogenesis and therapeutic strategies

Hepatitis C virus (HCV) is a significant health problem facing the world. This virus infects more than 170 million people worldwide and is considered the major cause of both acute and chronic hepatitis. Persons become infected mainly through parenteral exposure to infected material by blood transfusions or injections with nonsterile needles. Although the sexual behavior is considered as a high risk factor for HCV infection, the transmission of HCV infection through sexual means, is less frequently. Currently, the available treatment for patients with chronic HCV infection is interferon based therapies alone or in combination with ribavirin and protease inhibitors. Although a sustained virological response of patients to the applied therapy, a great portion of patients did not show any response. HCV infection is mostly associated with progressive liver diseases including fibrosis, cirrhosis and hepatocellular carcinoma. Although the focus of many patients and clinicians is sometimes limited to that problem, the natural history of HCV infection (HCV) is also associated with the development of several extrahepatic manifestations including dermatologic, rheumatologic, neurologic, and nephrologic complications, diabetes, arterial hypertension, autoantibodies and cryglobulins. Despite the notion that HCV-mediated extrahepatic manifestations are credible, the mechanism of their modulation is not fully described in detail. Therefore, the understanding of the molecular mechanisms of HCV-induced alteration of intracellular signal transduction pathways, during the course of HCV infection, may offer novel therapeutic targets for HCV-associated both hepatic and extrahepatic manifestations. This review will elaborate the etiopathogenesis of HCV-host interactions and summarize the current knowledge of HCV-associated diseases and their possible therapeutic strategies.

Signaling networks in human hepatocarcinogenesis--novel aspects and therapeutic options

Hepatocellular carcinoma (HCC) represents one of the most common human malignancies with poor prognosis. Because therapeutic strategies are insufficient for most HCC patients, there is a great need to determine the central molecular mechanisms and pathways in order to derive novel targets for systemic therapy. There is vast evidence that not only the dysregulation of distinct signaling cascades, but also their interactions at different levels, affect tumor cell function. Through these interactions, the effects of pathways can be increased, and even new tumor-supporting qualities acquired that further facilitate HCC progression. Although several approaches for the modulation of these relevant pathways are under development, future therapeutic strategies should take into account that oncogenic stimuli cannot be understood in a monodimensional manner. In order to avoid escape mechanisms during therapy, strategies based on comprehensive knowledge of the interactive regulatory network in hepatocarcinogenesis are necessary.

Novel therapeutic strategies for targeting liver cancer stem cells

The cancer stem cell (CSC) hypothesis was first proposed over 40 years ago. Advances in CSC isolation were first achieved in hematological malignancies, with the first CSC demonstrated in acute myeloid leukemia. However, using similar strategies and technologies, and taking advantage of available surface markers, CSCs have been more recently demonstrated in a growing range of epithelial and other solid organ malignancies, suggesting that the majority of malignancies are dependent on such a compartment.

Primary liver cancer consists predominantly of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). It is believed that hepatic progenitor cells (HPCs) could be the origin of some HCCs and ICCs. Furthermore, stem cell activators such as Wnt/β-catenin, TGF-β, Notch and Hedgehog signaling pathways also expedite tumorigenesis, and these pathways could serve as molecular targets to assist in designing cancer prevention strategies. Recent studies indicate that additional factors such as EpCAM, Lin28 or miR-181 may also contribute to HCC progression by targeting HCC CSCs. Various therapeutic drugs that directly modulate CSCs have been examined in vivo and in vitro. However, CSCs clearly have a complex pathogenesis, with a considerable crosstalk and redundancy in signaling pathways, and hence targeting single molecules or pathways may have a limited benefit for treatment. Many of the key signaling molecules are shared by both CSCs and normal stem cells, which add further challenges for designing molecularly targeted strategies specific to CSCs but sparing normal stem cells to avoid side effects. In addition to the direct control of CSCs, many other factors that are needed for the maintenance of CSCs, such as angiogenesis, vasculogenesis, invasion and migration, hypoxia, immune evasion, multiple drug resistance, and radioresistance, should be taken into consideration when designing therapeutic strategies for HCC.

Here we provide a brief review of molecular signaling in liver CSCs and present insights into new therapeutic strategies for targeting liver CSCs.

Liver stem cells and molecular signaling pathways in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal cancers. Surgical intervention is the only curative option, with only a small fraction of patients being eligible. Conventional chemotherapy and radiotherapy have not been effective in treating this disease, thus leaving patients with an extremely poor prognosis. In viral, alcoholic, and other chronic hepatitis, it has been shown that there is an activation of the progenitor/stem cell population, which has been found to reside in the canals of Hering. In fact, the degree of inflammation and the disease stage have been correlated with the degree of activation. Dysregulation of key regulatory signaling pathways such as transforming growth factor-beta/transforming growth factor-beta receptor (TGF-beta/TBR), insulin-like growth factor/IGF-1 receptor (IGF/IGF-1R), hepatocyte growth factor (HGF/MET), Wnt/beta-catenin/FZD, and transforming growth factor-alpha/epidermal growth factor receptor (TGF-alpha/EGFR) in this progenitor/stem cell population could give rise to HCC. Further understanding of these key signaling pathways and the molecular and genetic alterations associated with HCC could provide major advances in new therapeutic and diagnostic modalities.

Dysregulation of growth factor signaling in human hepatocellular carcinoma

Dysregulation of pleiotropic growth factors, receptors and their downstream signaling pathway components represent a central protumorigenic principle in human hepatocarcinogenesis. Especially the Insulin-like Growth Factor/IGF-1 receptor (IGF/IGF-1R), Hepatocyte Growth Factor (HGF/MET), Wingless (Wnt/beta-catenin/FZD), Transforming Growth Factor alpha/Epidermal Growth Factor receptor (TGFalpha/EGFR) and Transforming Growth Factor beta (TGFbeta/TbetaR) pathways contribute to proliferation, antiapoptosis and invasive behavior of tumor cells. This review focuses on the relevant alterations in these pathways identified in human human hepatocellular carcinomas (HCCs). Resultant functional effects are modulated by multiple cross-talks between the different signaling pathways and additional tumor-relevant factors, such as cyclooxygenase-2 and p53. Several specific strategies are currently under development such as receptor kinase inhibitors, neutralizing antibodies and antagonistic proteins, which may improve the systemic treatment of human HCCs.

Expression of Ki-67, transforming growth factor beta1, and B-cell lymphoma-leukemia-2 in liver tissue of patients with chronic liver diseases

BACKGROUND

The purpose of the present paper was to assess expression of proliferation, fibrosis and apoptosis markers in different phases of chronic liver diseases.

METHODS

Sixty-six adults with chronic liver diseases (chronic hepatitis C, n = 48; chronic hepatitis B, n = 10; alcohol chronic liver disease, n = 8) treated at the Department of Infectious Diseases and Hepatology from 1999 to 2001, composed the study group. Liver biopsy specimens were used for immunohistochemical assessment of expression of Ki-67, transforming growth factor beta1 (TGF-beta1) and B-cell lymphoma-leukemia-2 (Bcl-2). Grade of liver inflammation and stage of fibrosis were evaluated according to the Scheuer scale.

RESULTS

Expression of Ki-67 in hepatocytes was most intensive in patients with grade 2 and 3 inflammation. The expression in patients with grade 4 inflammation was low. The expression of Ki-67 in lymphocytes was most intensive in patients with grade 2 inflammation. Expression of TGF-beta1 in hepatocytes reached a maximum in patients with grade 2 or 3 inflammation and dropped in patients with grade 4 inflammation. There was a statistically significant correlation between stage of fibrosis and expression of TGF-beta1 in liver stromal cells. A very strong correlation was found between the expression of Bcl-2 in bile ductules epithelium and the grade of inflammation (P = 0.006). The expression of Bcl-2 in hepatocytes was observed only in patients with very intense liver inflammation (grade 3) and in patients with stage 3 or 4 fibrosis.

CONCLUSION

Processes of proliferation, fibrosis and apoptosis are not directly correlated to progression of liver disease. Expression of studied markers can be used for analysis of dynamics of these processes.

Overexpression of a DEAD box/RNA helicase protein, rck/p54, in human hepatocytes from patients with hepatitis C virus-related chronic hepatitis and its implication in hepatocellular carcinogenesis

Hepatitis C virus (HCV) infection is the most common cause of chronic hepatitis, which frequently progresses to hepatocellular carcinoma. The pathogenesis of its persistent infection and tumour progression has not been fully characterized yet. The RCK gene was previously cloned at the breakpoint of the t(11;14)(q23;q32) chromosome translocation observed in human B-cell lymphoma cell line RC-K8. The RCK protein, rck/p54, which is a 54-kDa cytoplasmic protein belonging to the DEAD box/RNA helicase family, is considered to facilitate the translation of mRNA(s) of genes for cell proliferation and malignant transformation not only in B-cell lymphomas having the t(11;14) translocation but also in other solid tumours. The aim of this work was to examine the involvement of rck/p54 in carcinogenesis of hepatocellular carcinoma from HCV-related chronic hepatitis. We examined the expression of rck/p54 in 29 cases of HCV-related chronic hepatitis and eight cases of hepatocellular carcinoma by immunohistochemistry and Western blot analysis. Twenty-six of 29 cases with HCV-related chronic hepatitis and all cases with hepatocellular carcinoma tested overexpressed rck/p54 protein. The expression of rck/p54 was lowered by treatment with IFN-alpha in two cases who showed the decrease in HCV RNA levels. These findings suggest that rck/p54 protein is possibly involved in the replication of HCV genomes in hepatocytes and in tumourigenesis of hepatocellular carcinomas.

Transforming growth factor beta in hepatitis C virus infection: in vivo and in vitro findings

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic liver disease (CLD) worldwide. The chronicity is a result of viral persistence and the ability of the virus to escape from the immune mechanisms of the host. Transforming growth factor (TGF)-beta is a cytokine thought to be responsible for viral persistence and liver fibrogenesis.

METHODS

The present study examined the levels of TGF-beta messenger (m)RNA by reverse transcription polymerase chain reaction (RT-PCR) in 35 liver biopsies and HCV-transfected HepG2 cells.

RESULTS

Transforming growth factor-beta mRNA was detected in nine liver biopsies from patients with chronic HCV infection, but was not detected in patients with non-HCV-related CLD or controls. On quantitation by semiquantitative PCR, TGF-beta mRNA levels ranged from 10-4.75 to 10-12.8 amol (10-7.46 +/- 3.771) in liver biopsies of HCV-related CLD. No significant difference in TGF-beta receptor levels was observed by RT-PCR in HCV- or non-HCV-related CLD by immunohistochemistry. To correlate these findings with in vitro experiments, levels of TGF-beta mRNA and its receptors were determined by RT-PCR in HepG2 cells transfected with HCV and hepatitis B virus (HBV) constructs, using mock-transfected cells as control. The TGF-beta protein levels were quantitated in these cell supernatants by enzyme immunoassay. The TGF-beta mRNA and protein levels were two logs and approximately 30 times higher in HCV-transfected HepG2 cells than in HBV- and mock-transfected cells, respectively. The TGF-beta receptors in HepG2 cells were also downregulated in HCV-transfected cells as compared with mock-transfected cells.

CONCLUSION

These observations suggest upregulation of TGF-beta in HCV infection and a probable role for TGF-beta in the pathogenesis of HCV-related CLD.

Identification, using cDNA macroarray analysis, of distinct gene expression profiles associated with pathological and virological features of hepatocellular carcinoma

It is still unclear as to whether the gene expression profile in HCV- or HBV-related HCC exhibits a degree of specificity and whether the development of HCC in a context of cirrhosis influences this gene profile. To address these issues, the expression profiles of 15 cases of HCC were analysed using cDNA macroarray. A global analysis and hierarchical clustering, demonstrated the heterogeneity of HCC patterns, with a majority of down-regulated genes. Statistical analysis clearly showed a distinction between the gene expression profiles of HCV- and HBV-related HCC. HBV-associated HCC exhibited involvement of different cellular pathways, those controlling apoptosis, p53 signalling and G1/S transition. In HCV-related HCC we identified a more heterogenous pattern with an over-expression of the TGF-beta induced gene. In HCC developing on non-cirrhotic tissues, beta-catenin encoding gene and genes implicated in the PKC pathway were specifically up-regulated. In addition, our investigation highlighted a distinct profiles of TGF-beta superfamily encoding genes in well, moderately or poorly differentiated HCC. Overall, our study supports the hypothesis that despite the heterogeneity of the HCC pattern, the large-scale screening of gene expression may provide data significant to our understanding of the mechanism of liver carcinogenesis.

Transforming growth factor-beta1 as a useful serologic marker of small hepatocellular carcinoma

BACKGROUND

Although alpha-fetoprotein (AFP) is a useful serologic marker of hepatocellular carcinoma (HCC), it has been reported insufficiently sensitive in detecting small HCCs. Plasma transforming growth factor-beta1 (TGFbeta1) has been reported to be elevated in HCC patients compared with liver cirrhosis patients. It has been reported that TGFbeta1 mRNA was overexpressed in HCC, especially in patients with small HCC and well-differentiated HCC compared with patients with liver cirrhosis. The current study investigated the usefulness of TGFbeta1 compared with AFP in the diagnosis of small HCCs.

METHODS

Thirty-eight patients with small HCC (< or = 3 cm), 31 patients with liver cirrhosis only, and 23 normal volunteers were studied. Using plasma TGFbeta1 and serum AFP levels measured at the time of diagnosis, the sensitivities and specificities were calculated in the diagnosis of small HCCs.

RESULTS

Plasma TGFbeta1 and serum AFP levels were significantly higher in patients with small HCC than in those with liver cirrhosis. In diagnosing small HCCs, the cut-off values of plasma TGFbeta1 and serum AFP were 800 pg/mL and 200 ng/mL, respectively, where the specificities were over 95%. At the cut-off level of plasma TGFbeta1 and serum AFP, the sensitivities were 68% and 24%, respectively.

CONCLUSIONS

The current results suggest that TGFbeta1 may be a useful serologic marker in detecting HCCs earlier because it shows higher sensitivity than, with specificity as, AFP in the diagnosis of small HCCs.