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HCC Tissues (hcc + tissue)

Distribution by Scientific Domains

Medical Sciences	86%

Distribution within Medical Sciences

Oncology & Radiotherapy	50%
Hepatology	24%
Gastroenterology & Hepatology	19%

Selected Abstracts

Genetic and epigenetic alterations of the KLF6 gene in hepatocellular carcinoma

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2006
Jaehwi Song
Abstract Background and Aim:, Kruppel-like factor 6 (KLF6) is a zinc finger tumor suppressor gene that is frequently mutated in several human cancers and is broadly involved in differentiation and development, growth-related signal transduction, cell proliferation, apoptosis, and angiogenesis. The aim of this study was to elucidate the potential etiological role of KLF6 in the development of hepatocellular carcinoma (HCC) in Korea. Methods:, The gene mutation, allelic loss, and methylation status of the KLF6 gene was analyzed in a series of 85 Korean patients: 21 with dysplastic nodules and 85 with HCC. Results:, No somatic mutations were observed in the patients with dysplastic nodules or with HCC. Allelic loss was found in five (6.8%) of 73 informative HCC tissues. Three of the five patients with allelic loss had HCC with hepatitis B virus infection and cirrhosis, and the remaining two had no viral infection and a non-specific background. In methylation analysis, unmethylated and methylated DNAs of the KLF6 gene were amplified in all corresponding non-neoplastic liver tissues. Only one HCC tissue showed methylated DNA without unmethylated DNA. Conclusions:, The results suggest that genetic and epigenetic alteration of KLF6 may play a minor role in the development of HCC. [source]

Nebivolol Dilates Human Penile Arteries and Reverses Erectile Dysfunction in Diabetic Rats through Enhancement of Nitric Oxide Signaling

THE JOURNAL OF SEXUAL MEDICINE, Issue 8 2010
Javier Angulo PhD
ABSTRACT Introduction., Traditional beta-blockers have sometimes been associated with erectile dysfunction (ED). Nebivolol is a cardioselective ,1 -adrenoceptor antagonist that promotes vasodilation through a nitric oxide (NO)-dependent mechanism. Aim., We evaluated the effects of nebivolol on the NO/cyclic guanosine monophosphate (cGMP) signaling pathway, on erectile function and dysfunction, and in human penile vascular tissues. Methods., Erectile response to cavernosal nerve electrical stimulation in control and diabetes-induced ED rats were evaluated, along with serum nitrite/nitrate (NOx) concentration and plasma/tissue cGMP levels. Endothelium-dependent and sildenafil-induced relaxation of isolated human corpus cavernosum (HCC) and human penile resistance arteries (HPRA) were also determined. Main Outcome Measures., The effects of nebivolol on erectile function and dysfunction and on NO/cGMP-mediated responses. Results., Treatment with nebivolol significantly potentiated erectile response in control rats, regardless of its effects on blood pressure. Nebivolol increased NOx and plasma cGMP by 3-fold and 2.75-fold, respectively, and significantly augmented the elevation of plasma cGMP produced by sildenafil. Nebivolol enhanced endothelium-dependent and sildenafil-induced relaxations of HCC tissue, and produced endothelium-dependent vasodilation of HPRA. Nebivolol, but not atenolol, significantly improved erectile response in diabetic rats (51.6%, 53.2%, and 87.1% of response at 3 Hz in nondiabetic rats, for vehicle-treated, atenolol-treated, and nebivolol-treated diabetic rats, respectively); after sildenafil administration, ED was completely reversed in nebivolol-treated diabetic rats (69.6% and 112% for diabetic rats treated with sildenafil and nebivolol plus sildenafil, respectively). Accordingly, nebivolol restored systemic NOx levels and cGMP content in penile tissue from these animals. Conclusions., Nebivolol in vivo activated the NO/cGMP pathway, enhanced erectile response and reversed ED in diabetic rats. Moreover, nebivolol in vitro potentiated NO/cGMP-mediated relaxation of human erectile tissues. These effects may account for the low incidence of ED in nebivolol-treated hypertensive patients. Nebivolol therefore may have utility in the treatment of ED, particularly ED associated with diabetes. Angulo J, Wright HM, Cuevas P, González-Corrochano R, Fernández A, Cuevas B, La Fuente JM, Gupta S, and de Tejada IS. Nebivolol dilates human penile arteries and reverses erectile dysfunction in diabetic rats through enhancement of nitric oxide signaling. J Sex Med 2010;7:2681,2697. [source]

Comparative analysis of ATP-binding cassette (ABC) transporter gene expression levels in peripheral blood leukocytes and in liver with hepatocellular carcinoma

CANCER SCIENCE, Issue 6 2004
Mohsen A. Moustafa
ATP-binding cassette (ABC) transporters comprise a superfamily of similar proteins involved in transmembrane transport of various substances. ABC transporter family members in the liver participate in bile formation and lipid metabolism. In order to assess whether peripheral blood leukocytes (PBL) are available as a surrogate for determination of the expression of ABC transporter genes in the liver, we compared ABC transporter gene expression levels in PBL with those in liver tissues from patients with hepatocellular carcinoma (HCC). We measured ABCA1, A2, B1-B4, C1°C5, G1 and G2 gene expression levels in PBL, and cancerous and non-cancerous portions of liver from patients with hepatocellular carcinoma by means of real time reverse-transcription (RT)-PCR. We could not detect ABCC5 expression in any tissue of the liver. Close correlations between ABCA2, C1 and 67 in PBL and in non-tumor tissues of the liver were found. Compared with the non-tumor part, HCC tissue expressed lower levels of ABCA1, B4 and G2. We think monitoring of ABCA2, C1 and G7 gene expression levels in PBL will be useful for selection of anti cancer agents and monitoring of drug resistance of HCC. Administration of chemotherapeutic agents which are substrates of ABCA1, B4 and G2 should be effective for the treatment of HCC. (Cancer Sci 2004; 95: 530,536) [source]

Enhanced expression of vascular endothelial growth factor-A in ground glass hepatocytes and its implication in hepatitis B virus hepatocarcinogenesis,

HEPATOLOGY, Issue 6 2009
Jui-Chu Yang
Ground glass hepatocytes (GGH) in chronic hepatitis B virus (HBV) infection harbor HBV pre-S deletion mutants in endoplasmic reticulum (ER) and exhibit complex biologic features such as ER stress, DNA damage, and growth advantage. The presence of pre-S mutants in serum has been shown to predict the development of hepatocellular carcinoma (HCC) in HBV carriers. GGHs hence represent a potentially preneoplastic lesion. Whether a specific growth factor is overexpressed and activated in GGHs remains to be clarified. In this study, growth factor(s) up-regulated by pre-S mutants was identified using a growth factor array in HuH-7 cells. Immunohistochemistry, reverse-transcriptase polymerase chain reaction, and Western blot analysis were performed to study the participation of these genes and their signal pathways in HuH-7 cells and liver tissues. We demonstrate that vascular endothelial growth factor-A (VEGF-A) was up-regulated by pre-S mutants in HuH-7 cells and further confirmed in GGHs by immunostaining. The VEGF-A up-regulation by pre-S mutants could be suppressed by vomitoxin, an ER stress inhibitor. Furthermore, pre-S mutants-expressed HuH-7 cells exhibited activation of Akt/mTOR (mammalian target of rapamycin) signaling and increased growth advantage, which could be inhibited by VEGF-A neutralization. Consistent with this notion, enhanced expression of VEGF-A and activation of Akt/mTOR signaling, comparable to the levels of paired HCC tissues, were also detected in HBV-related nontumorous livers. Conclusion: The enhanced expression of VEGF-A in GGHs provides potential mechanism to explain the progression from preneoplastic GGHs to HCC in chronic HBV infection. (HEPATOLOGY 2009;49:1962,1971.) [source]

Expression and role of Bcl-xL in human hepatocellular carcinomas

HEPATOLOGY, Issue 1 2001
Tetsuo Takehara
Transformed hepatocytes survive various apoptotic insults during their growth in vivo. However, molecular mechanisms that inhibit apoptosis and support their survival are not well understood. In this study, we investigated the expression and role of Bcl-xL, an antiapoptotic member of the Bcl-2 family, in human hepatocellular carcinoma (HCC). The Bcl-xL protein was expressed in HepG2, Hep3B, and Huh7 human hepatoma cell lines at high levels, but none of these cells expressed Bcl-2. Down-modulation of Bcl-xL by antisense oligonucleotide activated apoptosis in HepG2 cells in response to cellular stresses induced by staurosporine treatment or by serum starvation. Ectopic expression of transcriptionally active p53 alone was not sufficient for the activation of apoptosis in p53 -null Hep3B cells, but apoptosis was induced when endogenous Bcl-xL was simultaneously inhibited by antisense oligonucleotide in these cells. Bcl-xL was expressed in all 20 surgically resected human HCC tissues when examined by Western blot analysis and immunohistochemistry, and levels of its expression were higher in a subset of HCC tissues than those of adjacent nontumor liver tissues or normal livers. We conclude that Bcl-xL expressed in human HCC cells inhibits apoptosis produced by various cellular stresses, such as staurosporine treatment, serum starvation, and p53 activation, and may play an important role in their survival. [source]

Epigenetic and genetic alterations of PTEN in hepatocellular carcinoma

HEPATOLOGY RESEARCH, Issue 5 2007
Li Wang
Aim:, To investigate the roles of epigenetic and genetic alterations of the phosphatase and tensin homologue on chromosome 10 gene (PTEN) in carcinogenesis and the development of hepatocellular carcinomas (HCC). Methods:, A total of 56 cases of HCC tissues and six liver cell lines were studied for the expression of PTEN by immunohistochemistry and Western blot analysis. The PTEN gene mutations in exon5 and exon8 were detected by a combination of single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Methylation-specific PCR (MSP) was used to identify PTEN promoter methylation. Results:, Of the 56 cases of HCC, 24 (42.9%) expressed the PTEN protein. All surrounding liver tissues of the hepatoma (32 cases) were positive for PTEN. Of the six cell lines, three liver cancer cell lines showed a low expression of PTEN. Five mutations of 56 HCC samples were detected. All of them were located at intron4. No mutation was found in exon5 and exon8. After MSP analysis, we found nine cases of PTEN promoter methylation in 56 specimens (16.1%). However, no CpG island of PTEN was found to be methylated in all six liver cell lines. Conclusion:, The level of PTEN protein was altered in part of the HCC. The downregulation of PTEN expression may not be mainly associated with the PTEN mutations, but partly due to PTEN promoter methylation and other epigenetic regulation. [source]

Upregulation of miR-23a,27a,24 decreases transforming growth factor-beta-induced tumor-suppressive activities in human hepatocellular carcinoma cells

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2008
Shenglin Huang
Abstract Transforming growth factor-beta (TGF-beta) plays a dual and complex role in human cancer. In this report, we observe a specific set of MicroRNAs (miRNAs) changed in response to TGF-beta in human hepatocellular carcinoma (HCC) cells by miRNA microarray screening. A cluster of miRNA, miR-23a,27a,24, is induced in an early stage by TGF-beta in Huh-7 cells. Knockdown of Smad4, Smad2 or Smad3 expression by RNA interference can attenuate the response of miR-23a,27a,24 to TGF-beta addition, indicating that this induction is dependent on Smad pathway. We also explore that miR-23a,27a,24 can function as an antiapoptotic and proliferation-promoting factor in liver cancer cells. In addition, expression of this miRNA cluster is found to be remarkably upregulated in HCC tissues versus normal liver tissues. These findings suggest a novel, alternative mechanism through which TGF-beta could induce specific miRNA expression to escape from tumor-suppressive response in HCC cells. © 2008 Wiley-Liss, Inc. [source]

Differential DNA methylation associated with hepatitis B virus infection in hepatocellular carcinoma

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2007
Pei-Fen Su
Abstract Gene inactivation through DNA hypermethylation plays a pivotal role in carcinogenesis. This study aimed to profile aberrant DNA methylation in different stages of liver disease, namely noncirrhosis, cirrhosis and hepatocellular carcinoma (HCC), and also to clarify the influence of hepatitis B virus (HBV) infection on the aberrant DNA methylation in HCCs. Promoter methylation in p14ARF, p16INK4a, O6 -methylguanine-DNA methyltransferase (MGMT), glutathione S -transferase pi (GSTP1) and E-cadherin (E-Cad) genes of 58 HCCs paired with adjacent nontumorous tissues was assayed by methylation-specific PCR. HBV infection was determined using a hepatitis B virus surface antigen (HBsAg) serological assay. The frequency of p16INK4a promoter methylation increased from noncirrhotic, cirrhotic, to HCC tissues (noncirrhotic vs. HCC, p < 0.001), while that of GSTP1 promoter methylation increased in cirrhotic tissues compared to noncirrhotic ones (p = 0.029). The frequency of GSTP1 promoter hypermethylation is significantly higher in HCC than in nontumorous tissues (p = 0.022) from HBsAg-positive patients, but not the HBsAg-negative controls (p = 0.289). While the frequency of E-Cad promoter hypermethylation remained high in both nontumorous tissues and HCCs from HBsAg-positive patients (p = 0.438), it was lower in HCCs than in nontumorous tissues from HBsAg-negative patients (p = 0.002). In contrast, the frequency of p16INK4a, MGMT and p14ARF promoter hypermethylation in HCCs was unrelated to HBsAg status. In conclusion, aberrant DNA methylation may begin at different stages of liver disease in a gene-dependent manner. Moreover, HBV infection may enhance or maintain GSTP1 and E-Cad promoter methylation and thereby affect hepatocarcinogenesis. © 2007 Wiley-Liss, Inc. [source]

Role of interleukin-18 and its receptor in hepatocellular carcinoma associated with hepatitis C virus infection

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2006
Masami Asakawa
Abstract Interleukin (IL)-18 is a proinflammatory cytokine that is up-regulated in patients with hepatitis C virus (HCV) infection, which is the most common underlying disease in hepatocellular carcinoma (HCC). The purpose of our study was to investigate the role of IL-18 in HCC associated with HCV infection. Sixty-five patients with HCC and HCV infections who received curative surgical resections were examined in our study. The expression of the IL-18 receptor was investigated in HCC tissues obtained from these patients and in 2 HCC cell lines. Nuclear factor (NF)-,B activity and the expression of Bcl-xL and xIAP mRNA were tested in the cell lines using recombinant human (rh) IL-18. The IL-18 receptor was expressed in both the HCC tissues and the cell lines. NF-,B activation and the expression of Bcl-xL and xIAP mRNA were increased by rhIL-18. Moreover, rhIL-18 suppressed the apoptosis of HCC cells which was induced by etoposide in vitro. The overall survival rate (55.4%) was significantly worse in the IL-18 receptor-positive patients than in the IL-18 receptor-negative patients (p = 0.015). In a Cox multivariate analysis, the expression of the IL-18 receptor was found to be a significant predictor of a poor outcome in HCC patients. The expression of the IL-18 receptor and an antiapoptotic mechanism involving NF-,B activation in HCC cells may be implicated in a poor patient outcome. © 2005 Wiley-Liss, Inc. [source]

Replication efficiency and sequence analysis of full-length hepatitis B virus isolates from hepatocellular carcinoma tissues

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2002
Xu Lin
Abstract Prolonged replication of hepatitis B virus (HBV) in liver tissues of hepatitis B patients has been considered as an important risk factor for the development of malignancy. Few studies on full-length HBV sequencing in association with the replication efficiency of isolates from HCC tissues have been reported. To study the structural and functional genomics of HBV isolates from Chinese hepatocellular carcinoma (HCC) patients, full-length HBV genomes were amplified from 6 HBV-marker positive HCC tissues and used to transfect HepG2 cells. Five of 6 isolates showed high replicative efficiency. All isolates were of genotype C and "hot-spots" mutations were detected in the B cell and T helper (Th) cell epitopes of the envelope and the core region. In addition, the X region of 2 isolates contained a stop-codon mutation that was predicted to result in a truncated X protein. High replicative HBV immune escape mutants that persist in infected hepatocytes could be 1 of the important factors to initiate pathological processes for the development of HCC in Chinese patients. © 2002 Wiley-Liss, Inc. [source]

Genetic and epigenetic alterations of the KLF6 gene in hepatocellular carcinoma

Enhancement of poly-adenosine diphosphate-ribosylation in human hepatocellular carcinoma

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2000
Fumio Nomura
Abstract Background: Poly-adenosine diphosphate (ADP)-ribosylation, catalysed by poly(ADP-ribose) polymerase (PARP), is a post-translational modification of nuclear proteins and is involved in a wide range of biological processes including DNA repair, cell proliferation and malignant transformation. Alteration of this reaction in human hepatocellular carcinoma (HCC) is of interest, but has not yet been explored. The aim of this study was to evaluate poly-ADP-ribosylation and to compare the expression of PARP in HCC and adjacent non-tumour tissues. Methods: Tumorous and adjacent non-tumorous tissues were obtained from five consecutive patients with HCC during surgery for tumour resection. Tissue homogenates were subjected to ADP-ribosylation with [32P]-nicotinamide adenine dinucleotide. The ADP-ribosylated proteins were separated by sodium dodecylsulfate,polyacrylamide gel electrophoresis, followed by autoradiography. Expression of PARP was also evaluated by western blotting. Results: Several proteins were ADP-ribosylated in human HCC tissues. Notably, the radiolabelling of a 116-kDa protein was remarkably greater than that in adjacent non-tumorous tissues (86.5 ± 35.2 arbitrary units by densitometry vs 12.2 ± 9.9, mean± SD, n = 5, P < 0.02). The radiolabelling of the 116-kDa protein was decreased in the presence of PARP inhibitors in a concentration-dependent manner. Immunoblot analyses revealed that the radiolabelled protein was PARP and that its expression was significantly greater in HCC than in adjacent non-tumorous tissues (333 ± 204% of non-tumorous tissue, P < 0.05). Conclusions: We found that poly-ADP-ribosylation and PARP expression were significantly increased in human HCC compared with those in adjacent non-tumorous tissues in surgically obtained specimens. [source]

Hepatitis B virus X protein upregulates expression of calpain small subunit 1 via nuclear facter-,B/p65 in hepatoma cells

JOURNAL OF MEDICAL VIROLOGY, Issue 6 2010
Feng Zhang
Abstract Hepatitis B virus (HBV) infection is closely correlated with the development of hepatocellular carcinoma (HCC), in which hepatitis B virus X protein (HBx) plays crucial roles. HBx is believed to be a multifunctional oncoprotein. It has been reported that the calpain small subunit 1 (Capn4) is upregulated in the HCC tissues and involved in the metastasis of HCC. Therefore, we suppose that HBx may promote hepatoma cell migration through Capn4. In the present study, we investigated the effect of HBx on regulating Capn4 expression in human HCC cells. Our data showed that HBx could increase promoter activity of Capn4 and upregulate the expression of Capn4 at the levels of mRNA and protein in human hepatoma HepG2 (or H7402) cells using luciferase reporter gene assay, real-time quantitative RT-PCR assay and Western blot analysis. While, the RNA interference targeting HBx mRNA was able to abolish the upregulation. Interestingly, we found that the inhibition of nuclear factor-,B (NF-,B) mediated by siRNA targeting NF-,B/p65 mRNA or PDTC (an inhibitor of NF-,B) could attenuate the upregulation of Capn4. While, HBx failed to increase the promoter activity of Capn4 in hepatoma cells when the putative NF-,B binding site of the Capn4 promoter was mutant, suggesting that NF-,B is involved in the activation of Capn4 mediated by HBx. In function, wound healing assay showed that HBx could significantly enhance the migration ability of HepG2 cells through upregulating Capn4. Thus, we conclude that HBx upregulate Capn4 through NF-,B/p65 to promote migration of hepatoma cells. J. Med. Virol. 82:920,928, 2010. © 2010 Wiley-Liss, Inc. [source]

LAPTM4B-35 is a novel prognostic factor of hepatocellular carcinoma

JOURNAL OF SURGICAL ONCOLOGY, Issue 5 2010
Hua Yang MD
Abstract Background LAPTM4B-35 is a 35-kDa tetra-transmembrane protein overexpressed in hepatocellular carcinoma (HCC) and promotes cell survival, proliferation, and tumorigenesis. However, the potential clinical implications of LAPTM4B-35 in HCC are still unclear. This study is aimed to investigate the correlations between LAPTM4B-35 expression and prognosis in patients with HCC. Methods Western blot and immunohistochemistry assays were used to determine the expression of LAPTM4B-35 in HCCs and their paired noncancerous liver tissues from 65 patients. The correlations of LAPTM4B-35 expression with clinicopathological parameters were assessed by Chi-square test. Patient survival was determined by Kaplan,Meier method and log-rank test. Cox regression was adopted for multivariate analysis of prognostic factors. Results LAPTM4B-35 overexpression occurred in 76.9% of HCC tissues, while only in 4.6% of noncancerous liver tissues. Overexpression of LAPTM4B-35 was significantly associated with TNM staging and invasive tumors. Patients with higher LAPTM4B-35 expression had significantly poorer overall survival (OS) and disease-free survival (DFS) (both P,<,0.001). On multivariate analysis, elevated expression of LAPTM4B-35 was found to be an independent prognostic factor for OS and DFS (P,=,0.009, 0.043, respectively). Conclusions LAPTM4B-35 overexpression is an independent prognostic factor for OS and DFS of HCC. J. Surg. Oncol. 2010; 101:363,369. © 2010 Wiley-Liss, Inc. [source]

The tumor suppressor NPRL2 in hepatocellular carcinoma plays an important role in progression and can be served as an independent prognostic factor

JOURNAL OF SURGICAL ONCOLOGY, Issue 5 2009
Satoshi Otani MD
Abstract Background/Aims Hepatocarcinogenesis is a multifactorial, multistep process that involves the activation of oncogenes or the inactivation of tumor suppressor genes throughout the different stages of hepatocellular carcinoma (HCC) progression. NPRL2 is one of the candidate tumor suppressor genes identified on chromosome 3p21.3, a region which frequently contains genetic abnormalities found in the early stages of the development of various human cancers. In the current study, we aimed to evaluate NPRL2 expression in HCC and to explore the prognostic significance of NPRL2. Method We investigated NPRL2 mRNA expression in 70 HCC specimens, using quantitative real-time reverse transcription polymerase chain reaction analysis, and the correlation between NPRL2 expression and clinicopathologic parameters. Results NPRL2 mRNA was found to be expressed equally in both HCC tissues and corresponding non-cancerous liver tissues. However, higher NPRL2 expression correlated significantly with tumor size (P,=,0.0062) and serum PIVKA-II levels (P,=,0.0002). Univariate and multivariate analyses revealed that higher NPRL2 mRNA expression was an independent prognostic factor for overall survival (risk ratio 0.39; P,<,0.0001). Conclusion Our results suggest that NPRL2 mRNA expression has prognostic significance for the survival of patients with HCC. J. Surg. Oncol. 2009;100:358,363. © 2009 Wiley-Liss, Inc. [source]

Frequent integration of precore/core mutants of hepatitis B virus in human hepatocellular carcinoma tissues

JOURNAL OF VIRAL HEPATITIS, Issue 2 2000
Zhong
The development of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) frequently follows persistent HBV infection and may arise in individuals who are hepatitis B e antigen (HBeAg) negative, indicating the possible presence of precore/core mutants. It is unclear whether precore/core mutants are associated with tumour development or are selected for after chromosomal integration of the wild-type viral DNA. We studied the status and sequence variation of the precore/core region of HBV in 56 patients with HBV-associated HCC and in various corresponding non-tumour tissues by Southern blot analysis, polymerase chain reaction and direct sequencing. Southern blot showed that integrated HBV DNA existed in 43 of 56 HCC tissues. Sequence analysis revealed mutations in 65% of the HCC (26/40) and 45% (14/31) of the corresponding non-tumour tissues. The mutation at nucleotide (nt) 1896, known to prevent HBeAg synthesis, was detected in 40% (16/40) of the tumours and in 35.4% (11/31) of the non-tumour tissues. Other mutations were found at nt 1899 (eight of 40 in HCC; three of 31 in non-tumour tissues), nt 1898 (seven of 40 in HCC; two of 31 in non-tumour tissues), nt 1912 (seven of 40 in HCC; none of 31 in non-tumour tissues) and nt 1886 (three of 40 in HCC; none of 31 in non-tumour tissues). To determine whether this finding merely reflected the prevalence of such mutants in this geographical region, HBV DNA from the sera of patients (also in this region) with acute and chronic hepatitis were sequenced. The nt 1896 mutant was found in 5.6% (one of 18) of patients with acute hepatitis B and in 22.8% (nine of 35) of patients with chronic hepatitis B. However, the nt 1898 mutation was not found in any of these sera. The precore/core mutant was observed with increasing frequency from acute hepatitis to chronic hepatitis, non-tumour and HCC, and this difference in frequency was significant between HCC and acute hepatitis B groups (P < 0.01), suggesting that the precore/core mutant or hepatocytes harbouring this mutant may be under immune selection and that such mutations may facilitate integration and subsequent tumour development. [source]

The knockdown of endogenous replication factor C4 decreases the growth and enhances the chemosensitivity of hepatocellular carcinoma cells

LIVER INTERNATIONAL, Issue 1 2009
Masaaki Arai
Abstract Aims: To identify differentially expressed genes and thereby detect potential molecular targets for future therapies directed against hepatocellular carcinoma (HCC). Methods: To isolate differentially expressed genes between HCC and adjacent non-cancerous liver tissues, cDNA microarray and quantitative reverse transcriptase polymerase chain reaction analyses were performed. Gene knockdown experiments in HepG2 cells were also performed using small interfering RNAs (siRNAs). Proteins were detected by immunostaining, and cell proliferation was analysed using the MTT/WST-8 assay. Apoptosis and cell cycle analyses were performed using flow cytometry. Results: After an intensive screening for differentially expressed genes in HCC tissues, we isolated 23 upregulated genes in these lesions. Among these, we focused on the replication factor C4 (RFC4) gene. The expression of endogenous RFC4 proteins in HepG2 cells was found to be significantly reduced by RFC4 -specific siRNA. This inhibition of RFC4 expression correlated with a decrease in cellular proliferation, increased levels of apoptosis and a sensitizing of the cells to the DNA-damaging chemotherapeutic agents, doxorubicin and camptothecin. Conclusion: The replication factor C4 gene may be a novel target for developing cancer therapeutics, which can enhance the antitumour activity of chemotherapeutic agents that induce DNA damage. [source]

Proteomic profiling of hepatocellular carcinoma in Chinese cohort reveals heat-shock proteins (Hsp27, Hsp70, GRP78) up-regulation and their associated prognostic values

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2006
John M. Luk Dr.
Abstract To facilitate the identification of candidate molecular biomarkers that are linked to the pathogenesis of hepatocellular carcinoma (HCC), we investigated protein-expression profiles of 146 tissue specimens including 67 pairs of tumors and adjacent non-tumors resected from HCC patients as well as 12 normal livers by 2-DE. Among the 1800 spots displayed in the liver proteome, a total of 90 protein species were found to be significantly different between the three groups (P,<,0.05). Three of the top candidate markers up-regulated in HCC, with high receiver operating characteristic (ROC) curves, were identified by MS/MS analysis and belonged to the chaperone members: heat-shock protein (Hsp)27, Hsp70 and glucose-regulated protein (GRP)78. Over-expression of these chaperone proteins in HCC tissues was confirmed by Western blotting and immunohistochemistry. In correlation with clinico-pathological parameters, expression of Hsp27 was linked to ,-fetoprotein level (P,=,0.007) whereas up-regulation of GRP78 was associated with tumor venous infiltration (P,=,0.035). No significant association of Hsp70 with any pathologic features was observed. The present HCC proteome analysis revealed that in response to the stressful cancerous microenvironment, tumor cells strived to increase the expression of chaperone proteins for cyto-protective function and to enhance tumor growth and metastasis. [source]

Proteomic study of human hepatocellular carcinoma using two-dimensional difference gel electrophoresis with saturation cysteine dye

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2005
Kazuyasu Fujii
Abstract To identify the proteomic alterations associated with carcinogenesis of hepatocellular carcinoma (HCC), we compared the protein expression profiles of nine HCC cell lines with those of primary cultured hepatocytes established from five individuals. A differential proteomic study was performed by two-dimensional difference gel electrophoresis, in which protein samples are labeled with different fluorescent dyes and separated according to their isoelectric point and molecular weight. To label the protein samples, we used a newly developed and highly sensitive fluorescent dye, which reacts with all reduced cysteine residues of proteins. Principal component analysis based on the intensity of 1238,protein spots indicated that the HCC cells and the normal hepatocytes had distinct proteomic profiles. The Wilcoxon test was used to determine the protein spots whose intensity was differentially regulated in the HCC cells compared with the normal hepatocytes, and mass spectrometric analysis was used to identify the proteins corresponding to the spots. The proteins identified are involved in cell cycle regulation, binding to a tumor-suppressor gene product, fatty acid binding, and regulation of translation. Western blotting with specific antibodies revealed the overexpression of PCNA, EB1 and E-FABP in HCC tissues compared with noncancerous tissues. Aberrant regulation of EB1 and E-FABP has not previously been implicated in the development of HCC. [source]

Hepatitis B virus pre-S mutants, endoplasmic reticulum stress and hepatocarcinogenesis

CANCER SCIENCE, Issue 8 2006
Hui-Ching Wang
Although hepatitis B virus (HBV) has been documented to cause hepatocellular carcinoma (HCC), the exact role of HBV in the development of HCC remains enigmatic. Several hypotheses have been proposed to explain the potential mechanism, including insertional mutagenesis of HBV genomes and transcriptional activators of HBV gene products such as hepatitis B x protein (HBx) and truncated middle S mutants. In the past few years, we have identified two types of large HBV surface antigens (LHBs) with deletions at the pre-S1 (,S1-LHBs) and pre-S2 (,S2-LHBs) regions in ground glass hepatocytes. The pre-S mutant LHBs are retained in the endoplasmic reticulum (ER) and escape from immune attack. The pre-S mutants, particularly ,S2-LHBs, are increasingly prevalent in patients with hepatitis B e antigen (HBeAg)-positive chronic HBV infection, ranging from 6% before the 3rd decade to 35% in the 6th decade. In HCC patients, the two pre-S mutants were detected in 60% of HCC patients, in the serum and in HCC tissues. Pre-S mutant LHBs can initiate ER stress to induce oxidative DNA damage and genomic instability. Furthermore, pre-S mutant LHBs can upregulate cyclooxygenase-2 and cyclin A to induce cell cycle progression and proliferation of hepatocytes. In transgenic mice, the pre-S mutants can induce dysplasia of hepatocytes and development of HCC. In a nested control study, the presence of pre-S mutants carried a high risk of developing HCC in HBV carriers. In summary, the findings we describe in this review suggest a potential role for HBV pre-S mutants in HBV-related hepatocarcinogenesis, providing a model of viral carcinogenesis associated with ER stress. (Cancer Sci 2006; 97: 683,688) [source]

Cytochrome P450 gene expression levels in peripheral blood mononuclear cells in comparison with the liver

CANCER SCIENCE, Issue 6 2004
Motonobu Furukawa
Cytochromes P450 (CYPs) compose a superfamily of similar proteins involved in detoxification and elimination, as well as activation of a wide variety of compounds. Most CYP family members are localized in the liver. In order to assess whether peripheral blood leukocytes (PBL) are available as a surrogate for the determination of CYP gene expression levels in the liver, we compared CYP gene expression levels in PBL with those in liver tissues from patients with hepatocellular carcinoma (HCC). We measured CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 2F1, 2J2, 3A4, 3A5, 3A7, 4A11, 4B1 and CYP27 gene expressions in PBL and in the liver by real-time reverse-transcription (RT)-PCR. We could detect expression of CYP1A1, 1A2, P1B1, 2A6, 2B6 and 2E1 genes in PBL and all the genes except for CYP2F1 in the liver. Although gene expression levels within each subfamily were closely correlated within PBL and within the liver, a clear correlation of gene expression levels between PBL and liver tissues was found only for CYP4B1. Although inter-individual variation of the expression level of each CYP gene was wide, the induced level was proportional to the basal expression level. Therefore, monitoring of CYP gene expression levels in PBL, especially those of CYP4B1, could be available as a biomarker for monitoring of exposure to environmental pollutants and assessing the associated risk. Compared with non-tumor tissue, HCC tissues tended to show overexpression of multiple CYP genes, indicating that individualized selection and more effective administration of chemotherapeutic agents could perhaps be based on the pattern of CYP overexpression. [source]