Characterization of high-molecular-mass forms of basic fibroblast growth factor produced by hepatocellular carcinoma cells: possible involvement of basic fibroblast growth factor in hepatocarcinogenesis

FGF2 Functions in H2S's Attenuating Effect on Brain Injury Induced by Deep Hypothermic Circulatory Arrest in Rats

Deep hypothermic circulatory arrest (DHCA) can protect the brain during cardiac and aortic surgery by cooling the body, but meanwhile, temporary or permanent brain injury may arise. H2S protects neurons and the central nervous system, especially from secondary neuronal injury. We aim to unveil part of the mechanism of H2S's attenuating effect on brain injury induced by DHCA by exploring crucial target genes, and further promote the clinical application of H2S in DHCA. Nine SD rats were utilized to provide histological and microarray samples, and further the differential expression analysis. Then we conducted GO and KEGG pathway enrichment analyses on candidate genes. The protein-protein interaction (PPI) networks were performed by STRING and GeneMANIA. Crucial target genes' expression was validated by qRT-PCR and western blot. Histological study proved DHCA's damaging effect and H2S's repairing effect on brain. Next, we got 477 candidate genes by analyzing differentially expressed genes. The candidate genes were enriched in 303 GO terms and 28 KEGG pathways. Then nine genes were selected as crucial target genes. The function prediction by GeneMANIA suggested their close relation to immunity. FGF2 was identified as the crucial gene. FGF2 plays a vital role in the pathway when H2S attenuates brain injury after DHCA. Our research provides more information for understanding the mechanism of H2S attenuating brain injury after DHCA. We infer the process might probably be closely associated with immunity.

Capsaicin: Effects on the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent cancers, and to date, there have been very few drugs available that can improve survival, the most well-known being sorafenib. The pathogenesis of HCC is complex, involving multiple processes including abnormal cell and tissue regeneration, angiogenesis, genomic instability, cellular proliferation, and signaling pathway alterations. Capsaicin is a substance that holds increasingly high interest and is studied as a therapeutic option in a wide array of diseases. Several studies have investigated capsaicin roles in various stages of HCC oncogenesis. This paper aims to thoroughly detail the available information on the individual effects of capsaicin on the cellular mechanisms and pathways involved in HCC development, as well as investigate their possible cooperation and interferences. The synergistic antitumor effects of capsaicin and sorafenib are also addressed.

Multiple genomic signatures of selection in goats and sheep indigenous to a hot arid environment

Goats and sheep are versatile domesticates that have been integrated into diverse environments and production systems. Natural and artificial selection have shaped the variation in the two species, but natural selection has played the major role among indigenous flocks. To investigate signals of natural selection, we analyzed genotype data generated using the caprine and ovine 50K SNP BeadChips from Barki goats and sheep that are indigenous to a hot arid environment in Egypt's Coastal Zone of the Western Desert. We identify several candidate regions under selection that spanned 119 genes. A majority of the genes were involved in multiple signaling and signal transduction pathways in a wide variety of cellular and biochemical processes. In particular, selection signatures spanning several genes that directly or indirectly influenced traits for adaptation to hot arid environments, such as thermo-tolerance (melanogenesis) (FGF2, GNAI3, PLCB1), body size and development (BMP2, BMP4, GJA3, GJB2), energy and digestive metabolism (MYH, TRHDE, ALDH1A3), and nervous and autoimmune response (GRIA1, IL2, IL7, IL21, IL1R1) were identified. We also identified eight common candidate genes under selection in the two species and a shared selection signature that spanned a conserved syntenic segment to bovine chromosome 12 on caprine and ovine chromosomes 12 and 10, respectively, providing, most likely, the evidence for selection in a common environment in two different but closely related species. Our study highlights the importance of indigenous livestock as model organisms for investigating selection sweeps and genome-wide association mapping.

The JNK inhibitor SP600129 enhances apoptosis of HCC cells induced by the tumor suppressor WWOX

BACKGROUND/AIMS

The FRA16D fragile site gene WWOX is a tumor suppressor that participates in p53-mediated apoptosis. The c-jun N-terminal kinase JNK1 interacts with WWOX and inhibits apoptosis. We investigated the function of WWOX in human hepatocellular carcinoma (HCC) and the effect of JNK inhibition on WWOX-mediated apoptosis.

METHODS

Allelic imbalance on chromosome 16 was analyzed in 73 HCCs using 53 microsatellite markers. WWOX mRNA in HCC cell lines and primary HCCs was measured by real-time RT-PCR. Effects of WWOX on proliferation and apoptosis and the interaction between WWOX and JNK inhibition were examined.

RESULTS

Loss on chromosome 16 occurred in 34 of 73 HCCs. Of 11 HCC cell lines, 2 had low, 7 intermediate, and 2 had high WWOX mRNA. Of 51 primary tumors, 23 had low WWOX mRNA. Forced expression of WWOX in SNU387 cells decreased FGF2-mediated proliferation and enhanced apoptosis induced by staurosporine and the JNK inhibitor SP600129. Conversely, knockdown of WWOX in SNU449 cells using shRNA targeting WWOX increased proliferation and resistance to SP600129-induced apoptosis.

CONCLUSIONS

WWOX induces apoptosis and inhibits human HCC cell growth through a mechanism enhanced by JNK inhibition.

hSulf1 Sulfatase promotes apoptosis of hepatocellular cancer cells by decreasing heparin-binding growth factor signaling

BACKGROUND AND AIMS

The heparin-binding growth factors fibroblast growth factor (FGF) and hepatocyte growth factor (HGF) are potent mitogens for hepatocellular carcinomas (HCCs). Heparin-binding growth factor signaling is regulated by sulfation of cell-surface heparan sulfate proteoglycans (HSPGs). We hypothesized that hSulf1, a recently described sulfatase, regulates growth signaling in HCCs.

METHODS

Expression of hSulf1 in human HCC tumors was determined by real-time PCR. Down-regulation of hSulf1 expression was investigated by analyzing loss of heterozygosity (LOH) at the hSulf1 locus and the effect of the DNA methylation inhibitor 5-aza-deoxycytidine on hSulf1 expression. The subcellular location of hSulf1 and sulfation state of cell-surface HSPGs were assessed by immunocytochemistry. FGF and HGF signaling was examined by phospho-specific immunoblot analysis. Cell growth was measured by trypan blue exclusion, and the MTT assay and apoptosis were quantitated by fluorescence microscopy.

RESULTS

hSulf1 expression was decreased in 29% of HCCs and 82% of HCC cell lines. There was LOH at the hSulf1 locus in 42% of HCCs. Treatment with 5-aza-deoxycytidine reactivated hSulf1 expression in hSulf1-negative cell lines. Low hSulf1-expressing cells showed increased sulfation of cell-surface HSPGs, enhanced FGF and HGF-mediated signaling, and increased HCC cell growth. Conversely, forced expression of hSulf1 decreased sulfation of cell-surface HSPGs and abrogated growth signaling. HCC cells with high-level hSulf1 expression were sensitive to staurosporine- or cisplatin-induced apoptosis, whereas low expressing cells were resistant. Transfection of hSulf1 into hSulf1-negative cells restored staurosporine and cisplatin sensitivity.

CONCLUSIONS

Down-regulation of hSulf1 contributes to hepatocarcinogenesis by enhancing heparin-binding growth factor signaling and resistance to apoptosis.

Expression of HNFs and C/EBP alpha is correlated with immunocytochemical differentiation of cell lines derived from human hepatocellular carcinomas, hepatoblastomas and immortalized hepatocytes

Objective assessment of the differentiation grade of hepatocellular carcinomas (HCCs) is important for evaluation of the pathological diagnosis, prognosis and therapeutic treatment. Differentiation of hepatocytes is reflected by their expression of hepatic functional proteins in the mouse embryo, and liver-enriched transcription factors (LETFs) have been shown to regulate hepatic functional genes strictly. Previous reports demonstrated that the level of LETF expression is altered in HCC or preneoplastic nodules compared with noncancerous tissues. Therefore, LETF expression levels might be useful as a measure of HCC maturation. In this study, to clarify the correlation between the expression of LETFs and the differentiation grade of HCCs, we performed a quantitative analysis of the mRNA expressions of HNFs and C/EBP alpha using real-time reverse-transcription PCR and immunocytochemical analysis for hepatic functional proteins in twelve cell lines. Furthermore, we examined orthotopic transplantations of the HCC cell lines in C.B-17/Icrj-scid/scid mice and characterized the histologic and cytologic differentiation of the tumors that developed. Our results showed that comprehensive expressions of HNF-3beta, HNF-4 alpha, HNF-1 alpha, and C/EBP alpha were specific to HCCs with well-differentiated function and morphology. Furthermore, among these four transcription factors, HNF-4 alpha and HNF-1 alpha expressions showed synchronism and had a close relation with HCC differentiation. These in vitro results were confirmed in tumors developed in SCID mice in vivo. These findings suggested that HNF-4 alpha and HNF-1 alpha are useful markers to assess the degree of HCC differentiation, which we suggest could be evaluated objectively by the quantitative analysis of HNFs and C/EBP alpha in HCCs.

Increased DNA methyltransferase expression is associated with an early stage of human hepatocarcinogenesis

The present study was designed to determine whether changes in DNA methyltransferase (DNA MTase) expression are involved in hepatocarcinogenesis. We examined DNA MTase expression in normal liver tissue (with no remarkable histological findings), liver tissue showing chronic hepatitis or cirrhosis, which are generally thought to be precancerous conditions, and hepatocellular carcinomas (HCCs) using the reverse-transcriptase polymerase chain reaction assay. DNA MTase mRNA levels were significantly higher in liver tissue showing chronic hepatitis and cirrhosis (DNA MTase mRNA/beta-actin mRNA ratio = 0.30 +/- 0.22, n = 24, P < 0.01) than in normal liver tissue either from patients with liver metastatic lesions of colonic cancer (0.14 +/- 0.05, n = 6) or from patients with HCCs (0.16 +/- 0.07, n = 3). DNA MTase mRNA levels were even higher in HCC tissue (0.34 +/- 0.18, n = 29). These results suggest that increased DNA MTase expression may be an early event during hepatocarcinogenesis. DNA MTase is a potential target for HCC preventive therapy.

Basic fibroblast growth factor regulates proliferation and motility of human hepatoma cells by an autocrine mechanism

BACKGROUND/AIMS

Basic fibroblast growth factor has mitogenic and angiogenic properties. In this study, we aimed to evaluate the role of fibroblast growth factor in the development and progression of human hepatocellular carcinoma.

METHODS

The expression of basic fibroblast growth factor, fibroblast growth factor receptor-1, and a receptor isoform was investigated by in situ hybridization, immunohistochemistry, reverse transcription-polymerase chain reaction, Western blot analysis and confocal laser-scanning microscopy. The influence of exogenous basic fibroblast growth factor on DNA synthesis and motility of human hepatoma cells were also evaluated.

RESULTS

Basic fibroblast growth factor and fibroblast growth factor receptor-1 messenger RNAs were present mainly in tumor cells and less so in hepatocytes from noncancerous liver tissue. Immunoreactive products of basic fibroblast growth factor and fibroblast growth factor receptor-1 were observed in tumor cells. The isoform IIIc was expressed in hepatocellular carcinoma tissue and hepatoma cell lines. Exogenous basic fibroblast growth factor stimulated DNA synthesis and motility of hepatoma cells. The effect was more marked in poorly-differentiated hepatoma cells than in well-differentiated hepatoma cells. Fibroblast growth factor-1 expression on hepatoma cells was also more marked in poorly-differentiated hepatoma cells than in well-differentiated hepatoma cells. The stimulated motility on basic fibroblast growth factor was suppressed by an anti-fibroblast growth factor receptor-1 antibody.

CONCLUSIONS

Basic fibroblast growth factor may play an important role in the development and progression of hepatocellular carcinoma via an autocrine mechanism involving fibroblast growth factor and its receptor.

Expression of vascular endothelial growth factor in normal liver and hepatocellular carcinoma: an immunohistochemical study

Angiogenesis is of vital importance during the development and progression of solid tumors. To examine the role of vascular endothelial growth factor (VEGF) in hepatocarcinogenesis, we evaluated the expression of peptide in normal human liver (n = 6) and in 36 cases of hepatocellular carcinoma (HCC). Immunoreactivity for VEGF was present in the extracellular matrix of the portal tracts in the normal and nontumor part of liver, but not in hepatocytes and bile duct epithelium. For HCC, variable amounts of VEGF were expressed in 13 cases (36.1%) of tumor cells. Using a logistic regression model, expression of VEGF was significantly associated with a higher proliferative index (P = .01) and sonographic portal vein thrombosis (P = .05). However, VEGF expression did not correlate with a biochemical liver profile, alpha-fetoprotein levels, histological grading, gender, or clinical stage of cirrhosis (P > 0.1, respectively). Log-rank test showed that evaluation of VEGF did not provide more prognostic information (P > .5) than that from tumor volume and portal vein thrombosis (P < .01, respectively). In addition, VEGF was always present in the fibrovascular stroma or pericellular matrix of HCC, although no strong relationship was observed with the expression of VEGF in tumor cells (P > .5). Our data suggested that expression of VEGF may characterize a progression toward higher proliferation in hepatocarcinogenesis in vivo. The relevance of VEGF existing in the extracellular matrix of the normal liver and HCC remains to be clarified.

Plasma level of basic fibroblast growth factor increases with progression of chronic liver disease

Basic fibroblast growth factor (FGF) is thought to be involved in carcinogenesis and, to clarify its clinical significance, the study of its blood level in cancer patients is important. Plasma levels of basic FGF are reported to be elevated in some cancers. However, little is known of basic FGF levels in plasma in hepatocellular carcinoma (HCC). In this study, we measured basic FGF plasma levels in patients with chronic liver disease and compared the levels in chronic hepatitis (CH), liver cirrhosis (LC), and HCC. We also examined whether these levels were related to serum levels of asparate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, alkaline phosphatase, leucine aminopeptidase, total bilirubin, total protein, and albumin, and to the indocyanine green test (i.e., liver function tests) and to type III procollagen. 7S domain of IV type collagen, and hyaluronic acid (i.e., markers of liver fibrosis). Levels of basic FGF, determined by a quantitative "sandwich" enzyme immunoassay, were significantly elevated with the progression of liver disease; being 3.67 +/- 2.37 (mean +/- SD). 7.78 +/- 6.61, and 12.37 +/- 7.67 pg/ml in the CH, LC, and HCC groups, respectively. FGF levels were elevated to a greater extent in the HCC patients than in the CH (P < 0.0001) and LC patients (P = 0.0117). Levels were higher in LC than in CH (P = 0.0204). None of the liver function test findings or levels of markers of liver fibrosis were correlated with levels of basic FGF. These results suggest that circulating basic FGF could serve as a new indicator of the progression of chronic liver disease. The extremely elevated plasma of level basic FGF in the HCC group suggests that basic FGF may be related to the development of HCC.

Contribution of primary cultures of adult human hepatocytes to the pathophysiology of hepatocellular carcinoma

BACKGROUND/AIMS

The mechanisms of hepatocarcinogenesis are still poorly understood. The development of hepatocellular carcinoma has recently been shown to be associated with increased DNA synthesis in cirrhosis. The aim of this work was to determine whether the high rate of hepatocyte regeneration observed in cirrhotic liver with hepatocellular carcinoma is associated with the presence of a growth factor that could be detectable in the serum.

METHODS

Adult human hepatocytes in primary culture, allowing the evaluation of the release of circulating hepatotrophic factors, were used. These cultures were treated for 48 h with serum from patients with cirrhosis with and without hepatocellular carcinoma, from patients with liver metastasis, and from healthy subjects. The rate of DNA synthesis in these cultures was assessed by measuring the amount of [3H]-thymidine incorporation into genomic DNA.

RESULTS

On average, the synthesis of DNA was increased 2.5-, 2.2-, 2.1-, and 2.3-fold, respectively, in response to serum from patients with cirrhosis with hepatocellular carcinoma, from patients with cirrhosis without hepatocellular carcinoma, from patients with liver metastasis, and from healthy subjects.

CONCLUSIONS

We conclude that the hepatotrophic activity of the serum is not significantly different in patients with cirrhosis with or without hepatocellular carcinoma. These results suggest that the increased DNA synthesis in hepatocytes of cirrhotic liver with hepatocellular carcinoma might be due to proliferative factor(s) acting by paracrine or autocrine pathways.

Pancreatic cancer: the potential clinical relevance of alterations in growth factors and their receptors

Molecular alterations play a key role in the pathogenesis of gastrointestinal cancers. In the present paper we describe relevant molecular alterations in human pancreatic adenocarcinomas. Overexpression of growth factor receptors (EGF receptor, c-erbB2, c-erbB3, TGF beta receptor I-III), growth factors (EGF, TGF alpha, TGF beta-1-3, aFGF, bFGF), adhesion molecules (ICAM-1, ELAM-1) and gene mutations (p53, K-ras, DCC, APC) are present in a significant number of these tumors. These changes stimulate tumor growth and enhance the metastatic behavior of pancreatic cancer cells and thereby may contribute to shorter postoperative survival following tumor resection.

Transcriptional regulation of basic fibroblast growth factor gene by p53 in human glioblastoma and hepatocellular carcinoma cells

Mutations of the p53 gene are found in various human cancers. The frequency of its mutation is reported to increase during tumor progression in most tumors. In human gliomas, mutations of the p53 gene are found in about one-third of the malignant forms and in few of the benign ones, indicating their possible involvement in tumor progression. On the other hand, we have recently shown that basic fibroblast growth factor (basic FGF) plays a crucial role in tumor progression as an autocrine growth factor in tissues of human gliomas. Therefore, we hypothesized that p53 might regulate the promoter activity of the basic FGF gene, which has several GC boxes and no typical TATA box. In this study, cotransfection assays using human glioblastoma and hepatocellular carcinoma cells and establishment of stable cell lines expressing mutant-type p53 were performed. The basic FGF gene promoter was demonstrated to be regulated by p53 at the transcriptional level and its basal core promoter was found to be responsive to p53. Expression of endogenous basic FGF was also demonstrated to be activated by mutant type p53. Wild-type p53 repressed gene expression of the basic FGF and its mutant activated it in vitro, implying one of the possible pathways in tumor progression.

Purification and characterization of the 210-amino acid recombinant basic fibroblast growth factor form (FGF-2)

Four forms of basic fibroblast-growth factor (bFGF or FGF-2) using one AUG (155 amino acids) and three upstream CUG (210, 201 and 196 amino acids) start codons, were synthesized through an alternative use of initiation codons. The 210-amino acid form of FGF-2 (210FGF-2) was expressed in a plasmid vector under the control of a bacteriophage T7 RNA polymerase promoter system in Escherichia coli. Characterization of the purified protein was performed by electrospray mass spectrometry and Edman degradation. The recombinant 210FGF-2 produced in E. coli had a mitogenic activity similar to the 146-amino acid form extracted from tissues.

Increased expression of acidic and basic fibroblast growth factors in chronic pancreatitis

Acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) belong to a family of mitogenic polypeptides that are involved in cellular proliferation and differentiation. In this study we investigated the potential role of aFGF and bFGF in chronic pancreatitis (CP), a fibrotic condition associated with acinar cell dedifferentiation and atrophy, and fibroblastic proliferation. By immunohistochemistry, aFGF and bFGF were abundant in pancreatic ductal and acinar cells in pancreatic tissues from CP patients. Immunoblotting with the same highly specific monoclonal antibodies demonstrated a marked increase in aFGF and bFGF in pancreatic homogenates from CP patients by comparison with the normal pancreas. Northern blot analysis indicated that, by comparison with normal controls, 16 of 21 CP tissues exhibited a 14-fold increase in aFGF mRNA levels, and 19 of 21 CP tissues exhibited a 15-fold increase in bFGF mRNA levels. In situ hybridization confirmed that this overexpression occurred in ductal and acinar cells, and indicated that both mRNA moieties colocalized with their respective proteins. These findings suggest that aFGF and bFGF may either be involved in the pathobiological mechanisms that occur in CP, or that their overexpression may be the consequence of other perturbations that occur in this disorder.

Inhibition of cell attachment, invasion and metastasis of human carcinoma cells by anti-integrin beta 1 subunit antibody

We investigated the expression of beta 1 integrins in human carcinoma cell lines, and the anti-metastatic and anti-invasive effects of a newly established anti-human beta 1 subunit monoclonal antibody designated NCC-INT-7. All the examined carcinoma cell lines expressed beta 1 integrins upon immunoblot analysis. NCC-INT-7 completely inhibited the adhesion of carcinoma cells to laminin, fibronectin, collagens and acetone-fixed tissues including lung, liver and brain. In an in vitro invasion model, NCC-INT-7 inhibited the invasion of human bladder carcinoma cell line T24 and human gastric carcinoma cell lines TMK-1, MKN-45 and MKN-74 through an artificially reconstructed basement membrane. In an in vivo nude mouse peritoneal dissemination model using MKN-45 and TMK-1, NCC-INT-7 significantly reduced the number of tumor nodules in the mesentery. In an in vivo nude mouse liver metastasis model using a serially transplantable human colonic carcinoma, COL-2-JCK, NCC-INT-7 significantly reduced the number of tumor nodules in liver. These results indicate that beta 1 integrins play an important role in the tissue attachment, migration, invasion and metastasis of human carcinoma cells, and that this new monoclonal antibody is useful for studies aimed at prevention of metastasis.