Significance of Aurora B overexpression in hepatocellular carcinoma. Aurora B Overexpression in HCC

<p>Abstract</p> <p>Background</p> <p>To investigate the significance of Aurora B expression in hepatocellular carcinoma (HCC).</p> <p>Methods</p> <p>The <it>Aurora B </it>and <it>Aurora A </it>mRNA level was measured in 160 HCCs and the paired nontumorous liver tissues by reverse transcription-polymerase chain reaction. Mutations of the <it>p53 </it>and <it>β-catenin </it>genes were analyzed in 134 and 150 tumors, respectively, by direct sequencing of exon 2 to exon 11 of <it>p53 </it>and exon 3 of <it>β-catenin</it>. Anticancer effects of AZD1152-HQPA, an Aurora B kinase selective inhibitor, were examined in Huh-7 and Hep3B cell lines.</p> <p>Results</p> <p><it>Aurora B </it>was overexpressed in 98 (61%) of 160 HCCs and in all 7 HCC cell lines examined. The overexpression of <it>Aurora B </it>was associated with <it>Aurora A </it>overexpression (<it>P </it>= 0.0003) and <it>p53 </it>mutation (<it>P </it>= 0.002) and was inversely associated with <it>β</it>-<it>catenin </it>mutation (<it>P </it>= 0.002). <it>Aurora B </it>overexpression correlated with worse clinicopathologic characteristics. Multivariate analysis confirmed that <it>Aurora B </it>overexpression was an independent poor prognostic factor, despite its interaction with Aurora A overexpression and mutations of <it>p53 </it>and <it>β</it>-<it>catenin</it>. In Huh-7 and Hep3B cells, AZD1152-HQPA induced proliferation blockade, histone H3 (Ser10) dephosphorylation, cell cycle disturbance, and apoptosis.</p> <p>Conclusion</p> <p><it>Aurora B </it>overexpression is an independent molecular marker predicting tumor invasiveness and poor prognosis of HCC. Aurora B kinase selective inhibitors are potential therapeutic agents for HCC treatment.</p

Male Germ Cell-Specific RNA Binding Protein RBMY: A New Oncogene Explaining Male Predominance in Liver Cancer

Male gender is a risk factor for the development of hepatocellular carcinoma (HCC) but the mechanisms are not fully understood. The RNA binding motif gene on the Y chromosome (RBMY), encoding a male germ cell-specific RNA splicing regulator during spermatogenesis, is aberrantly activated in human male liver cancers. This study investigated the in vitro oncogenic effect and the possible mechanism of RBMY in human hepatoma cell line HepG2 and its in vivo effect with regards to the livers of human and transgenic mice. RBMY expression in HepG2 cells was knocked down by RNA interference and the cancer cell phenotype was characterized by soft-agar colony formation and sensitivity to hydrogen-peroxide-induced apoptosis. The results revealed that RBMY knockdown reduced the transformation and anti-apoptotic efficiency of HepG2 cells. The expression of RBMY, androgen receptor (AR) and its inhibitory variant AR45, AR-targeted genes insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) was analyzed by quantitative RT-PCR. Up-regulation of AR45 variant and reduction of IGF-1 and IGFBP-3 expression was only detected in RBMY knockdown cells. Moreover, RBMY positive human male HCC expressed lower level of AR45 as compared to RBMY negative HCC tissues. The oncogenic properties of RBMY were further assessed in a transgenic mouse model. Liver-specific RBMY transgenic mice developed hepatic pre-cancerous lesions, adenoma, and HCC. RBMY also accelerated chemical carcinogen-induced hepatocarcinogenesis in transgenic mice. Collectively, these findings suggest that Y chromosome-specific RBMY is likely involved in the regulation of androgen receptor activity and contributes to male predominance of HCC

Dominance of Functional Androgen Receptor Allele with Longer Cag Repeat in Hepatitis B Virus-Related Female Hepatocarcinogenesis

The CAG polymorphism in exon 1 of the androgen receptor (AR) gene has been shown associated with the development of human male hepatocellular carcinoma (HCC) with the shorter AR alleles conferring a higher risk. However, the significance of AR-CAG repeats in female hepatocarcinogenesis remains to be addressed. In this study, seventy-six pairs of female HCCs and corresponding nontumorous tissues were collected, and 180 cirrhotic nodules were microdissected from 7 cirrhotic livers. The clonality status, functional AR alleles, and CAG repeat number of each sample were determined by AR methylation analysis. In a total of 44 monoclonal HCCs, the mean of CAG repeats in the active alleles was significantly longer than that in the inactive alleles (22.0 +/- 2.8 versus 20.7 +/- 3 .6; P = 0.047). When we divided HCCs into hepatitis B virus- positive [HBV(+)] and HBV(-) subgroups, the long AR allele dominance was found only in HBV(+) ones (P = 0.006 versus P = 0.923). Notably, the preference of long CAG repeat has also been found in the 100 monoclonal nodules (P = 0.013). For comparison of monoclonal nodules obtained from the same individual, a dominant long AR allele was found in 6 patients. The proportion of monoclonal cirrhotic nodules and HCCs expressing longer AR allele, 69 and 68%, are both significantly higher than 50%, the assumed value in normal liver (P < 0.001 for cirrhotic nodules and P = 0.005 for HCC ). The dominance is again only prominent in HBV-infected HCCs [85% for HBV(+) HCC ; P < 0.001 but 54% for HBV(-) HCC; P = 0.27]. The results indicated that in female hepatocarcinogenesis, hepatocytes expressing the longer AR allele seem to be favorably selected for autonomous growth and transformation, especially in synergy with HBV infection

The Aurora Kinase Inhibitor Ve-465 Has Anticancer Effects in Pre-Clinical Studies of Human Hepatocellular Carcinoma

Background/Aims: Hepatocelfular carcinoma (HCC) is one of the most common malignancies worldwide and novel therapies are urgently needed. Recently, aberrant expression of Aurora kinases has been reported in various human cancers including HCC. We sought to investigate the potential of a potent and selective Aurora kinase inhibitor, VE-465, for targeted therapy of HCC . Methods: Cytotoxicity effects of VE -465 were tested in Huh-7 and HepG2 cell lines. Inhibition of Aurora kinase activity was demonstrated by Western blotting and immunofluorescence staining. Mitotic perturbation was visualized by confocal microscopy. Cell cycle profiles and apoptosis were assessed by flow cytometry . In vivo efficacy was determined in nude mice with human HCC xenografts. Results: We demonstrated that VE-465 induced proliferation blockade, histone H3 (Ser10) dephosphorylation, mitotic disturbance, endoreduplication, and apoptosis in Huh-7 and HepG2 cells. We also found that VE-465 suppressed Aurora kinase activity, prevented tumor growth, and induced apoptosis in a Huh-7 xenograft model. Conclusions: These findings show that VE-465 has potent anticancer effects in human HCC . Inhibitors of Aurora kinases may deserve further exploration as molecular targeted agents against HCC. (C) 2008 European Association for the Study of the Liver

Association of Downregulation of Cyclin D1 and of Overexpression of Cyclin E with P53 Mutation, High Tumor Grade and Poor Prognosis in Hepatocellular Carcinoma

Background/Aims: The major regulatory events leading to cell proliferation occur in the G(1) phase of cell cycle, and the deranged expression of G(1) cyclins is related to oncogenesis. In this study, we analyzed the aberrant expressions of cyclins D1 and E, and their role in hepatocellular carcinoma. Methods: We examined paired hepatocellular carcinoma and liver RNAs taken from 71 patients who had been followed for more than 4 years after tumor resection, using reverse transcription- polymerase chain reaction supplemented with Northern blotting and immunohistochemistry. The genetic alterations of the p53 gene were also studied. Results: Downregulation of cyclin D1 mRNA was detected in 29 hepatocellular carcinomas (40.8%), while overexpression was detected in only 4 hepatocellular carcinomas (5.6%). Downregulation of cyclin D1 was associated significantly with large hepatocellular carcinomas (p=0.0006) and poorly differentiated (grades HI- IV) hepatocellular carcinoma (p=0. 057), but not seen in any of 15 minute hepatocellular carcinomas (less than or equal to 2.5 cm in size). Cyclin E mRNA was overexpressed in 40 hepatocellular carcinomas, regardless of tumor size. Overexpression of cyclin E was significantly associated with poorly differentiated and invasive hepatocellular carcinoma (p=0.001 and p=0.015, respectively). Downregulation of cyclin D1 and overexpression of cyclin E were significantly associated with the p53 mutation (p=0.023 and p=0.005, respectively). Hepatocellular carcinomas expressing both downregulation of cyclin D1 and overexpression of cyclin E had the worst 4-year survival (p <0.03), and higher frequencies of the p53 mutation (p<0.001), large hepatocellular carcinoma (p<0.001), and invasive tumor (p<0. 01). Conclusions: The deranged expressions of G(1) cyclins correlate with the p 53 mutation, tumor progression, and tumor biologic behavior of hepatocellular carcinoma. Overexpression of cyclin E occurs early, and downregulation of cyclin D1 late in hepatocellular carcinoma growth

Beta-Catenin Mutations Are Associated with a Subset of Low-Stage Hepatocellular Carcinoma Negative for Hepatitis B Virus and with Favorable Prognosis

To better understand the role of beta-catenin mutation in hepatocellular carcinoma (HCC), we correlated the gene mutation with hepatitis virus B ( HBV) and hepatitis virus C (HCV) status and the clinicopathological features in 366 patients with resected primary unifocal HCC. beta-Catenin mutations were also analyzed in 55 patients with multifocal HCC (68 tumors ). Of the whole series, 57 (13.1%) of 434 tumors examined had beta-catenin mutations, 34 occurred at the serine/threonine residues of the GSK-3beta region of beta-catenin. Outside the GSK-3beta phosphorylation site, codons 32 and 34 were two mutational hot spots (17 tumors). The non-HBV-related HCC that was predominantly HCV related had a higher frequency of mutation (P:

Prolonged Asymptomatic Dense Deposit Disease in Chinese - Report of 2 Cases in Taiwan

Dense deposit disease (DDD) is a less common form of membranoproliferative glomerulonephritis (MPGN). The disease occurs predominantly in children and young adults and the prognosis is variable. DDD varies considerably in incidence among different populations and has not been reported in Chinese. Herein we reported 2 cases of DDD in young Chinese girls in Taiwan. Although 1 case (case 2) had mild hypertension, both patients had asymptomatic proteinuria and ran a benign course of 8 and 14 years, respectively, The histological features of case 1 resembled membranous glomerulonephritis (MGN) on hematoxylin-eosin stain, but revealed DDD on periodic acid Schiff and chromotrope-2R silver methenamine stains. Whereas case 2 showed focal MPGN on light miscroscopy, she had a fine granular immunofluorescence pattern resembling MGN. Characteristic intramembranous dense deposits were demonstrated by electron microscopy in the basement membranes of the glomeruli, Bowman's capsules and the renal tubules. Both patients were followed closely, and had stable normal renal function 1 year after renal biopsy