Expression of insulin-like growth factor II (IGF-II) in human hepatocellular carcinomas: an immunohistochemical study

Tissue miRNA 483-3p expression predicts tumor recurrence after surgical resection in histologically advanced hepatocellular carcinomas

The choice of surgical treatment for hepatocellular carcinoma (HCC) depends on several prognostic variables, among which histological features, like microvascular invasion and tumor grade, are well established. This study aims to identify the tissue miRNAs predictive of recurrence after liver resection in "histologically advanced" HCC. We selected 54 patients: 15 retrospective resected patients without recurrence (group A), 19 retrospective resected patients with HCC recurrence (group B), and 20 prospective patients (group C), with 4 recurrence cases. All selected HCC were "histologically advanced" (high Edmondson grade and/or presence of microvascular invasion). A wide spectrum of miRNAs was studied with TaqMan Human microRNA Arrays; qRT-PCR assays were used to validate results on selected miRNAs; immunohistochemistry for IGF2 was applied to study the mechanism of miR-483-3p. As a result, a significant differential expression between group A and B was found for 255 miRNAs. Among them we selected miR-483-3p and miR-548e (P<0.001). As a single variable (group C), HCC with miR-483-3p downregulation (mean fold increase 0.21) had 44.4% of recurrence cases; HCC with miR-483-3p upregulation (mean fold increase 5.94) showed no recurrence cases (P=0.011). At immunohistochemistry (group C), the HCC with loss of cytoplasmic IGF2 expression showed a down-regulation of miR-483-3p (fold increase 0.57). In conclusion, in patients with "histologically advanced" HCC, the analysis of specific tissue miRNAs (particularly miR-483-3p) could help identify the recurrence risk and choose which treatment algorithm to implement (follow-up, resection or transplantation). This could have an important impact on patient survival and transplantation outcome, improving organ allocation.

The hepatitis B virus-associated tumor microenvironment in hepatocellular carcinoma

In contrast to a majority of cancer types, the initiation of hepatocellular carcinoma (HCC) is intimately associated with a chronically diseased liver tissue, with one of the most prevalent etiological factors being hepatitis B virus (HBV). Transformation of the liver in HBV-associated HCC often follows from or accompanies long-term symptoms of chronic hepatitis, inflammation and cirrhosis, and viral load is a strong predictor for both incidence and progression of HCC. Besides aiding in transformation, HBV plays a crucial role in modulating the accumulation and activation of both cellular components of the microenvironment, such as immune cells and fibroblasts, and non-cellular components of the microenvironment, such as cytokines and growth factors, markedly influencing disease progression and prognosis. This review will explore some of these components and mechanisms to demonstrate both underlying themes and the inherent complexity of these interacting systems in the initiation, progression, and metastasis of HBV-positive HCC.

Characterization of the inflammatory microenvironment and identification of potential therapeutic targets in wilms tumors

The role of inflammation in cancer has been reported in various adult malignant neoplasms. By contrast, its role in pediatric tumors has not been as well studied. In this study, we have identified and characterized the infiltration of various inflammatory immune cells as well as inflammatory markers in Wilms tumor (WT), the most common renal malignancy in children. Formalin-fixed paraffin-embedded blocks from tumors and autologous normal kidneys were immunostained for inflammatory immune cells (T cells, B cells, macrophages, neutrophils, and mast cells) and inflammatory markers such as cyclooxygenase-2 (COX-2), hypoxia-inducible factor 1α, phosphorylated STAT3, phosphorylated extracellular signal-related kinases 1 and 2, inducible nitric oxide synthase, nitrotyrosine, and vascular endothelial growth factor expression. Overall, we found that there was predominant infiltration of tumor-associated macrophages in the tumor stroma where COX-2 was robustly expressed. The other tumor-associated inflammatory markers were also mostly localized to tumor stroma. Hence, we speculate that COX-2-mediated inflammatory microenvironment may be important in WT growth and potential therapies targeting this pathway may be beneficial and should be tested in clinical settings for the treatment of WTs in children.

The insulin-like growth factor (IGF) signaling axis and hepatitis C virus-associated carcinogenesis (review)

Insulin-like growth factor (IGF) signaling plays an important autocrine, paracrine and endocrine role in growth promotion involving various tissues and organs. Synthesis of both IGFs (IGF-1 and IGF-2) in normal conditions takes place mainly in the liver even if the proteins can be produced in every cell of the human body. The alterations in the IGF signaling axis in human hepatocarcinogenesis are described, but mechanisms of the interactions between expression of oncogenic hepatitis C virus (HCV) proteins and components of the IGF system in progression of chronic hepatitis C to primary hepatocellular carcinoma (HCC) have been poorly recognised. In advanced stages of liver diseases, lowered serum levels of IGF-1 and IGF-2 have been documented. This was supposed to reflect significant damage to liver parenchyma, a decreased number of growth hormone receptors and a decreased genomic expression of IGF binding proteins (IGF BPs). In HCC, a decreased tissue expression of IGF-1, and an increased expression of IGF-1 receptor (IGF-1R) were noted, compared to the control. Potential mechanisms of augmented IGF-2 expression in HCC were also described and dysregulation of IGF signaling in HCC was concluded to occur predominantly at the level of IGF-2 bioavailability. The review aimed at presentation of involvement of IGF-1, IGF-1R and IGF BPs (mostly IGF BP-3 and IGF BP-6) in HCV-related hepatocarcinogenesis. Manifestation of various mRNA transcripts and IGF-1 proteins and their potential involvement in carcinogenesis are also discussed.

Insulin-like growth factor II in hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common malignant human tumors. Hepatocarcinogenesis is a multistep process with a multifactorial etiology. Chronic hepatitis B and hepatitis C virus infection, alcohol drinking and cirrhosis of any etiology are the major risk factors for hepatocellular carcinoma. Growth factors, their receptors and related proteins are involved in the process of malignant transformation. The IGF axis is involved in the proliferation and differentiation of normal, transformed and malignant hepatocytes. In the context of hepatocarcinogenesis, IGF-II has, in particular, been investigated thoroughly. Increased IGF-II bioavailability, protease activity of IGF-binding proteins and IGF-I receptor expression, decreased expression of IGF-II receptor and IGF-binding proteins are thought to contribute to hepatocellular carcinoma genesis. This review will first focus on the role of the IGF axis in hepatocarcinogenesis. In the second part it will emphasize circulating IGF-II levels in chronic liver disease and hepatocellular carcinoma, and diagnostic application of serum IGF-II level in both small and larger hepatocellular carcinoma.

Reactivation of the insulin-like growth factor-II signaling pathway in human hepatocellular carcinoma

Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma (HCC). Especially the overexpression of the fetal growth factor IGF-II, IGF-Ireceptor (IGF-IR), and cytoplasmic downstream effectors such as insulin-receptor substrates (IRS) contribute to proliferation, anti-apoptosis, and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-II signaling during HCC development and progression. Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies, various experimental strategies have been developed, including neutralizing antibodies and selective receptor kinase inhibitors, with respect to the specific and efficient reduction of oncogenic IGF-II/IGF-IR-signaling.

The role of the IGF system in cancer growth and metastasis: overview and recent insights

IGF-I receptor (IGF-IR) signaling and functions are mediated through the activities of a complex molecular network of positive (e.g., type I IGF) and negative (e.g., the type II IGF receptor, IGF-IIR) effectors. Under normal physiological conditions, the balance between the expression and activities of these molecules is tightly controlled. Changes in this delicate balance (e.g., overexpression of one effector) may trigger a cascade of molecular events that can ultimately lead to malignancy. In recent years, evidence has been mounting that the IGF axis may be involved in human cancer progression and can be targeted for therapeutic intervention. Here we review old and more recent evidence on the role the IGF system in malignancy and highlight experimental and clinical studies that provide novel insights into the complex mechanisms that contribute to its oncogenic potential. Controversies arising from conflicting evidence on the relevance of IGF-IR and its ligands to human cancer are discussed. Our review highlights the importance of viewing the IGF axis as a complex multifactorial system and shows that changes in the expression levels of any one component of the axis, in a given malignancy, should be interpreted with caution and viewed in a wider context that takes into account the expression levels, state of activation, accessibility, and functionality of other interacting components. Because IGF targeting for anticancer therapy is rapidly becoming a clinical reality, an understanding of this complexity is timely because it is likely to have an impact on the design, mode of action, and clinical outcomes of newly developed drugs.

Identification of a unique gene expression signature that differentiates hepatocellular adenoma from well-differentiated hepatocellular carcinoma

It is often difficult to distinguish hepatocellular adenoma (HCA) from well-differentiated hepatocellular carcinoma (WDHCC) when limited tissue from a needle biopsy is evaluated. The aim of this study was to identify gene expression patterns that can distinguish HCA from WDHCC, with the ultimate goal of discovering novel diagnostic markers. Gene expression profile analysis was performed using Affymetrix U133Plus2 GeneChip microarrays on RNA isolated from frozen tissue of 6 HCA and 8 WDHCC specimens. Statistical analysis of microarray data identified 63 genes whose expression levels were significantly different between HCA and WDHCC. These included 57 genes overexpressed by HCA and 6 overexpressed by WDHCC. Eight genes were chosen for further analysis by quantitative RT-PCR on RNA derived from archived, paraffin-embedded tissue blocks of an independent validation set comprising 9 HCAs and 9 HCCs. Seven of the 8 genes demonstrated average expression differences between HCA and HCC that were concordant with the microarray findings, and their expression pattern correctly classified the 18 tumors into HCA and HCC using unsupervised clustering analysis. Furthermore, immunohistochemical staining performed on a third, independent set of 27 HCAs and 33 HCCs confirmed the expression differences at protein levels for 5 of the genes. Taken together, our data demonstrate significant molecular differences between HCA and WDHCC, despite their morphologic similarity. More importantly, we have identified a unique set of genes whose expression pattern can discriminate between these two types of hepatocellular neoplasms, suggesting the possibility of future development of ancillary molecular and immunohistochemical diagnostic methods.

Regulation of vascular endothelial growth factor expression by insulin-like growth factor-II in human keratinocytes, differential involvement of mitogen-activated protein kinases and feedback inhibition of protein kinase C

BACKGROUND

Vascular endothelial growth factor (VEGF) is overexpressed in hyperproliferative diseases such as psoriasis and cancer, which are characterized by an increased angiogenesis. It was reported that insulin-like growth factor (IGF)-II is highly expressed during hepatocarcinogenesis and is increased in psoriatic lesions. The increase in IGF-II is believed to be associated with the pathogenesis of these diseases by increasing angiogenesis.

OBJECTIVES

In order to investigate the relationship between IGF-II and angiogenesis-related VEGF, VEGF expression in the IGF-II-treated human keratinocytes was monitored and the IGF-II signalling pathways were examined with respect to VEGF expression.

METHODS

Northern blot analysis for the VEGF mRNA levels and an enzyme-linked immunosorbent assay for the VEGF protein were performed to determine if IGF-II (100 ng mL(-1)) can increase the VEGF expression levels with or without a pretreatment with protein inhibitors in primary normal human keratinocytes and HaCaT cells.

RESULTS

The mRNA and protein levels of VEGF by IGF-II were increased in a time-dependent manner and reached the maximum level 2 h and 8 h after the IGF-II treatment, respectively. However, this increase was abrogated by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor but not by a p38 inhibitor. The IGF-II-mediated VEGF induction was also effectively inhibited by a pretreatment with the tyrosine kinase inhibitor and Src inhibitor. The PI3-kinase inhibitor also inhibited the expression of VEGF by IGF-II. However, the phospholipase C (PLC) and protein kinase C (PKC) inhibitors did not block the increases of VEGF mRNA level and its protein level by IGF-II, and the PKC inhibitor instead increased VEGF expression by IGF-II.

CONCLUSIONS

These results suggest that the tyrosine kinase-Src-ERK1/2 pathway and the PI3-kinase pathway are involved in IGF-II-mediated VEGF expression, but PKC is negatively associated in the IGF-II-mediated VEGF expression.

Molecular profiling of human hepatocellular carcinoma defines mutually exclusive interferon regulation and insulin-like growth factor II overexpression

Molecular subtyping of human hepatocellular carcinoma (HCC) with potential mechanistic and therapeutic impact has not been achieved thus far. We have analyzed the mRNA expression patterns of 43 different human HCC samples and 3 HCC cell lines in comparison with normal adult liver using high-density cDNA microarrays. Two main groups of HCC, designated group A (65%) and group B (35%), were distinguished based on clustering of the most highly varying genes. Group A HCCs were characterized by induction of a number of interferon (IFN)-regulated genes, whereas group B was characterized mainly by down-regulation of several apoptosis-relevant and IFN-regulated genes. The number of apoptotic tumor cells and tumor-infiltrating lymphocytes was significantly higher in tumors of group A as compared with those of group B. Based on the expression pattern, group B was further subdivided into two subgroups, designated subgroup B1 (6 of 43 tumors, 14%) and subgroup B2 (9 of 43 tumors, 21%). A prominent characteristic of subgroup B1 was high overexpression of insulin-like growth factor (IGF)-II. All tested HCC cell lines expressed equally high concentrations of IGF-II transcripts and co-segregated with group B1 in clustering. IGF-II overexpression and induction of IFN-related genes were mutually exclusive, even when analysis was extended to other cancer expression profile studies. Moreover, IFN-gamma treatment substantially reduced IGF-II expression in HCC cells. In conclusion, cDNA microarray analyses provided subtyping of HCCs that is related to intratumor inflammation and tumor cell apoptosis. This profiling may be of mechanistic and therapeutic impact because IGF-II overexpression has been linked to reduced apoptosis and increased proliferation and may be accessible to therapeutic intervention.

IGF-II-mediated COX-2 gene expression in human keratinocytes through extracellular signal-regulated kinase pathway

We monitored cyclooxygenase-2 (COX-2) expression in the insulin-like growth factor-II (IGF-II) treated human keratinocytes and explored the IGF-II signaling pathways with respect to the expression of COX-2. IGF-II induced COX-2 mRNA and protein levels, and the up-regulation of COX-2 expression by IGF-II was reduced by pretreatment with inhibitors of tyrosine kinase, Src and PI3-kinase. The inhibition of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) 1 also reduced the increased expression of COX-2 by IGF-II, but the inhibition of p38 did not. To further examine the roles of these mitogen-activated protein kinases (MAPKs) in IGF-II-induced COX-2 expression, we performed COX-2 promoter analysis using dominant negative plasmids of MEK1 (DN-MEK1), p38 (DN-p38) and JNK1 (DN-JNK1). Although IGF-II increased COX-2 promoter activity approximately 2.5-fold, this increase was blocked by cotransfection with DN-MEK1 or DN-JNK1. However, DN-p38 did not block the IGF-II-induced COX-2 promoter activity. In addition, inhibition of ERK or JNK1 reduced the increase of IGF-II-induced prostaglandin E(2) synthesis or cell proliferation. These results suggest that IGF-II induces COX-2 expression through the tyrosine kinase-Src-ERK and tyrosine kinase-PI3-kinase pathways, but not via p38 MAPK pathway, and that the basal JNK activity is required for the upregulation of COX-2 by IGF-II, as well.

Different expression of hepatitis B surface antigen between hepatocellular carcinoma and its surrounding liver tissue, studied using a tissue microarray

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and is highly associated with chronic liver disease, including hepatitis B viral infection. In order to study the association between hepatitis B virus (HBV) infection and HCC development, tissue microarrays were used to detect the expression of hepatitis B surface antigen (HBsAg) in 194 HCCs and their surrounding liver tissues, using anti-HBsAg monoclonal antibody. The results showed that the expression of HBsAg is significantly lower in tumour tissue than in non-tumour tissue. Among the 138 cases with positive serum HBsAg, expression of HBsAg was more frequently detected in non-tumour tissue (103 cases, 75%) than in tumour tissue (11 cases, 8%). RT-PCR and Southern blot analysis were performed to explore the mechanism of the decreased expression of HBsAg in tumour cells. The RT-PCR results showed that absence or decreased expression of the HBV S gene was detected in 3/15 (20%) and 6/15 (40%) HCCs, respectively. Integration of HBV in 23 pairs of HCCs and their matched non-tumour liver tissues was studied by Southern blot. The results showed that the integrated HBV S gene sequence was detected in 19/23 tumours (83%) and 1/23 non-tumour tissues (4%), whereas the free replicative virus form was observed in 3/23 tumours (13%) and 14/23 non-tumour tissues (61%). These findings suggest that HBsAg-negative results in tumour tissues were directly related to HBV DNA insertion and provide new insights into the involvement of HBsAg in hepatocarcinogenesis.

The effects of insulin-like growth factors on tumorigenesis and neoplastic growth

Several decades of basic and clinical research have demonstrated that there is an association between the insulin-like growth factors (IGFs) and neoplasia. We begin with a brief discussion of the function and regulation of expression of the IGFs, their receptors and the IGF-binding proteins (IGFBPs). A number of investigational interventional strategies targeting the GH or IGFs are then reviewed. Finally, we have assembled the available scientific knowledge about this relationship for each of the major tumor types. The tumors have been grouped together by organ system and for each of the major tumors, various key elements of the relationship between IGFs and tumor growth are discussed. Specifically these include the presence or absence of autocrine IGF-I and IGF-II production; presence or absence of IGF-I and IGF-II receptor expression; the expression and functions of the IGFBPs; in vitro and in vivo experiments involving therapeutic interventions; and available results from clinical trials evaluating the effect of GH/IGF axis down-regulation in various malignancies.

Hepatitis B virus biology

Hepadnaviruses (hepatitis B viruses) cause transient and chronic infections of the liver. Transient infections run a course of several months, and chronic infections are often lifelong. Chronic infections can lead to liver failure with cirrhosis and hepatocellular carcinoma. The replication strategy of these viruses has been described in great detail, but virus-host interactions leading to acute and chronic disease are still poorly understood. Studies on how the virus evades the immune response to cause prolonged transient infections with high-titer viremia and lifelong infections with an ongoing inflammation of the liver are still at an early stage, and the role of the virus in liver cancer is still elusive. The state of knowledge in this very active field is therefore reviewed with an emphasis on past accomplishments as well as goals for the future.

Insulin-like growth factor II signaling in neoplastic proliferation is blocked by transgenic expression of the metalloproteinase inhibitor TIMP-1

Insulin-like growth factor (IGF) II is overexpressed in many human cancers and is reactivated by, and crucial for viral oncogene (SV40 T antigen, [TAg])-induced tumorigenesis in several tumor models. Using a double transgenic murine hepatic tumor model, we demonstrate that tissue inhibitor of metalloproteinase 1 (TIMP-1) blocks liver hyperplasia during tumor development, despite TAg-mediated reactivation of IGF-II. Because the activity of IGFs is controlled by IGF-binding proteins (IGFBPs), we investigated whether TIMP-1 overexpression altered the IGFBP status in the transgenic liver. Ligand blotting showed that IGFBP-3 protein levels were increased in TIMP-1-overexpressing double transgenic littermates, whereas IGFBP-3 mRNA levels were not different, suggesting that TIMP-1 affects IGFBP-3 at a posttranscriptional level. IGFBP-3 proteolysis assays demonstrated that IGFBP-3 degradation was lower in TIMP-1-overexpressing livers, and zymography showed that matrix metalloproteinases (MMPs) were present in the liver homogenates and were capable of degrading IGFBP-3. As a consequence of reduced IGFBP-3 proteolysis and elevated IGFBP-3 protein levels, dissociable IGF-II levels were significantly lower in TIMP-1-overexpressing animals. This decrease in bioavailable IGF-II ultimately resulted in diminished IGF-I receptor signaling in vivo as evidenced by diminished receptor kinase activity and decreased tyrosine phosphorylation of the IGF-I receptor downstream effectors, insulin receptor substrate 1 (IRS-1), extracellular signal regulatory kinase (Erk)-1, and Erk-2. Together, these results provide evidence that TIMP-1 inhibits liver hyperplasia, an early event in TAg-mediated tumorigenesis, by reducing the activity of the tumor-inducing mitogen, IGF-II. These data implicate the control of MMP-mediated degradation of IGFBPs as a novel therapy for controlling IGF bioavailability in cancer.

Clinical relevance of transforming growth factor-beta 1 in the urine of patients with hepatocellular carcinoma

To assess the clinical relevance of transforming growth factor-beta 1 (TGF-beta 1) in the urine of patients with hepatocellular carcinoma (HCC), TGF-beta 1 was measured, by radioimmunoassay, in 140 patients with HCC, 50 cirrhotic patients, 30 patients with chronic active hepatitis, and 50 healthy controls. The results indicate that there were significantly increased urinary TGF-beta 1 levels in patients with HCC. Raised TGF-beta 1 levels were associated, in a dose-related fashion, with increased risk for development of HCC (odds ratio, 1.05, 95% confidence interval, 1.03-1.07). HCC patients with raised TGF-beta 1 levels had shorter survival than those with normal TGF-beta 1 levels (p = 0.038). TGF-beta 1 levels decreased after successful anticancer therapy (p < 0.0001). There was an inverse correlation between TGF-beta 1 and serum alpha-fetoprotein (AFP) (r = -0.199, p < 0.04). Receiver operating characteristics (ROC) curve analysis indicated that parallel determination of TGF-beta 1 and AFP significantly increased the sensitivity and diagnostic accuracy, with a high specificity. In conclusion, raised urinary TGF-beta 1 was associated with HCC development. It is a predictor of poor prognosis, and a tumor marker for diagnosis and therapeutic follow-up of HCC.

Immunohistochemical evidence of insulin-like growth factor II in human small hepatocellular carcinoma with hepatitis C virus infection: relationship to fatty change in carcinoma cells

It has recently been reported that insulin-like growth factor II (IGF-II) may play a role in the pathogenesis of hepatocellular carcinoma (HCC). We studied the relationship between the expression of IGF-II and fatty change in human small HCC using immunohistochemical staining techniques. Liver biopsy specimens were obtained from 35 patients with HCC (consisting of 15 patients with fatty change and 20 patients without fatty change). All patients had serum markers for the hepatitis C virus (HCV) and histological findings obtained from non-tumourous lesions showed liver cirrhosis or chronic active hepatitis. Immunohistochemical staining was performed using a monoclonal antibody against rat IGF-II. A positive immunoreaction was found in 69% (24/35) of HCC. Insulin-like growth factor II was immunodetected in 80% (12/15) of HCC with fatty change but only in 60% (12/20) of those without fatty change. In most cases, IGF-II was not found in hepatocytes from non-tumourous lesions. We believe this to be the first time that IGF-II has been detected immunohistochemically in small HCC derived from HCV infection. This growth factor was more frequently immunodetected in HCC with fatty change than without. As insulin is an essential factor for the metabolism of fatty acids, IGF-II may play an important role in both fatty degeneration and in the proliferation of HCC cells. Furthermore, immunohistochemical IGF-II staining may contribute to the diagnosis of HCC, particularly in early stages accompanied by fatty change.

Co-localisation of insulin-like growth factor II and the proliferation marker MIB1 in hepatocellular carcinoma cells

AIM

To assess the effect of insulin-like growth factor II (IGF-II) on proliferation of hepatocellular carcinoma (HCC) cells.

METHODS

Expression of IGF-II mRNA and protein was detected in 10 archival HCC specimens using in situ hybridisation and immunohistochemistry, respectively. Expression of the Ki-67 antigen, a proliferation marker, was determined immunohistochemically on the same sections.

RESULTS

Increased expression of IGF-II mRNA and protein was detected in five of the 10 HCCs in cells located at the periphery of tumour nests. The pattern of localisation of IGF-II was almost identical with that of Ki-67 antigen.

CONCLUSIONS

Most of the Ki-67 antigen positive cells co-expressed IGF-II, suggesting that IGF-II may act as an autocrine or paracrine growth factor, and may play an important role in the development of HCC.

Insulin-like growth factor II expression in primary meningeal hemangiopericytoma and its metastasis to the liver accompanied by hypoglycemia

In situ hybridization and immunohistochemistry were performed to detect insulin-like growth factor II (IGF2) in tissue sections obtained from a patient with hypoglycemia in association with primary meningeal hemangiopericytoma and metastatic foci in the liver. High levels of IGF2 mRNA and IGF2 peptide were detected in both primary and metastatic tumor cells, although the serum IGF2 level was within the normal range. Because the serum level of IGF binding protein-3 was low, whereas the serum insulin level and other endocrinological examinations were normal, we speculate that the mechanism of the hypoglycemia was associated with the tumor-produced IGF2.

Differential expression of transforming growth factor alpha and insulin-like growth factor II in chronic active hepatitis B, cirrhosis and hepatocellular carcinoma

In the present study we investigated the expression of transforming growth factor alpha and insulin-like growth factor II to explain the role of these growth factors in the development of hepatocellular carcinoma from chronic active hepatitis B and cirrhosis. The expression of transforming growth factor alpha and insulin-like growth factor II was tested in 38 tissue samples from patients with chronic active hepatitis B, 32 cirrhosis and 31 hepatocellular carcinoma, by immunohistochemical staining using monoclonal anti-transforming growth factor alpha and anti-insulin-like growth factor II. All patients were seropositive for HBsAg. Transforming growth factor alpha was expressed in 26 (68.4%) of 38 chronic active hepatitis B, 18 (56.3%) of 32 cirrhosis and 16 (51.6%) of 31 hepatocellular carcinoma tissue samples. Transforming growth factor alpha was found in the periportal hepatocytes of chronic active hepatitis B and in regenerating hepatocytes of cirrhotic nodules. In hepatocellular carcinoma tissues, transforming growth factor alpha-containing tumor cells were evenly distributed within the tumor tissues but focal distribution limited to a part of tumor tissues was also observed. The expression of insulin-like growth factor II was observed in 30 (93.8%) of 32 cirrhosis and all the 31 hepatocellular carcinoma tissue samples tested, but not in chronic active hepatitis B samples. Insulin-like growth factor II was expressed in most hepatocytes of regenerating nodules and in tumorous as well as non-tumorous hepatocytes of hepatocellular carcinoma tissues.(ABSTRACT TRUNCATED AT 250 WORDS)