Genome-wide expression patterns associated with oncogenesis and sarcomatous transdifferentation of cholangiocarcinoma

BACKGROUND: The molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation. METHODS: Genes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells. RESULTS: Using unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (<0.5 fold change). Expression of SPP1, EFNB2, E2F2, IRX3, PTTG1, PPARγ, KRT17, UCHL1, IGFBP7 and SPARC proteins was immunohistochemically verified in human and hamster CC tissues. Additional unsupervised hierarchical clustering analysis of sarcomatoid CC cells compared to three adenocarcinomatous CC cell lines revealed 292 differentially upregulated genes (>4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC. CONCLUSION: The deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis

Treatment Outcomes of Clevudine versus Lamivudine at Week 48 in Naïve Patients with HBeAg Positive Chronic Hepatitis B

The authors assessed the efficacy and antiviral resistance of 48-week clevudine therapy versus lamivudine in treatment of naïve patients with HBeAg positive chronic hepatitis B. In this retrospective study, a total of 116 HBeAg positive patients, who received 30 mg of clevudine once daily (n=53) or 100 mg of lamivudine once daily (n=63) for 48 weeks, were included. At week 48, clevudine therapy produced a significantly greater mean reductions in serum HBV DNA levels from baseline than lamivudine therapy (-5.2 vs. -4.2 log10IU/mL; P=0.005). Furthermore, a significantly higher proportion of patients on clevudine achieved negative serum HBV DNA by PCR (<13 IU/mL) at week 48 (60.4% vs. 38.1%; P=0.025). The incidence of virologic breakthrough in the clevudine group was significantly lower than in the lamivudine group (9.4% vs. 25.4%; P=0.031). However, rates of alanine aminotransferase normalization and HBeAg loss or seroconversion were similar in the two groups (83.0% vs. 81.0%, 11.3% vs. 11.1%; P=0.813, 1.000, respectively). In conclusion, clevudine is more potent for viral suppression and lower for antiviral resistance at week 48 than lamivudine in treatment of naïve patients with HBeAg positive chronic hepatitis B

Pro-oncogenic potential of NM23-H2 in hepatocellular carcinoma

NM23 is a family of structurally and functionally conserved proteins known as nucleoside diphosphate kinases (NDPK). There is abundant mRNA expression of NM23-H1, NM23-H2, or a read through transcript (NM23-LV) in the primary sites of hepatocellular carcinoma (HCC). Although the NM23-H1 protein is implicated as a metastasis suppressor, the role of NM23-H2 appears to be less understood. Thus, the aim of this study was to examine whether NM23-H2 is associated with hepatocarcinogenesis. The level of NM23-H2 expression in tumor tissues and the surrounding matrix appeared to be independent of etiology and tumor differentiation. Its subcellular localization was confined to mainly the cytoplasm and to a lesser extent in the nucleus. Ectopic expression of NM23-H2 in NIH3T3 fibroblasts and HLK3 hepatocytes showed a transformed morphology, enhanced focus formation, and allowed anchorage-independent growth. Finally, NIH3T3 fibroblasts and HLK3 hepatocytes stably expressing NM23-H2 produced tumors in athymic mice and showed c-Myc over-expression. In addition, NF-κB and cyclin D1 expression were also increased by NM23-H2. Lentiviral delivery of NM23-H2 shRNA inhibited tumor growth of xenotransplanted tumors produced from HLK3 cells stably expressing NM23-H2. Collectively, these results indicate that NM23-H2 may be pro-oncogenic in hepatocarcinogenesis

NF-Y-dependent cyclin B2 expression in colorectal adenocarcinoma

PURPOSE: Cyclin B2, a G(2)-M cyclin, is overexpressed in colorectal adenocarcinomas compared with the normal mucosa. This study examined the level of cyclin B2 overexpression according to the histologic findings and investigated the mechanism(s) and clinical implications of cyclin B2 overexpression in colorectal adenocarcinomas. EXPERIMENTAL DESIGN: The immunoreactivity of the polyclonal antibodies to cyclin B2 was determined in colorectal cancer cells. The transcriptional regulation of cyclin B2 by NF-Y was analyzed using an in vitro transfection assay and an in vivo chromatin immunoprecipitation assay. The proliferative activity of the colorectal cancer cells in relation to cyclin B2 overexpression was further examined. RESULTS: The cytoplasmic distribution of cyclin B2 immunoreactivity was positive in 42 of 65 (64.6%) cases of colorectal adenocarcinoma, and the level was similar regardless of the histologic type. A dominant-negative form of NF-YA effectively inhibited the cyclin B2 promoter activity, and NF-Y was found to bind three conserved CCAAT boxes in the cyclin B2 promoter in colorectal adenocarcinoma cells. Tumor cells with a higher functional cyclin B2 activity grew faster than those with a lower activity. Furthermore, there was a correlation between the cells showing immunoreactivity to cyclin B2 and those containing the proliferating cell nuclear antigen, a G1-S cyclin, which is also downstream of NF-Y in colorectal adenocarcinoma cells. CONCLUSIONS: Cyclin B2 seems to be a molecular marker of a colorectal adenocarcinoma and that its up-regulation and coordinate expression of the other cell cycle-related genes by NF-Y might contribute to tumor cell proliferation by accelerating cell cycle progression.21CFr ontier Human Genome Project grant FG-1-2 and Korea Research Foundation grants F00351and F00153

Ischemic colitis secondary to inferior mesenteric arteriovenous fistula and portal vein stenosis in a liver transplant recipient

Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a less common and more serious manifestation of AVF. We report a case of ischemic colitis secondary to inferior mesenteric AVF in a patient who underwent a previous liver transplantation, subsequently developed portal vein stenosis, and then presented with acute lower gastrointestinal bleeding. He underwent percutaneous transhepatic placement of a portal vein stent and left colectomy

Frequency of Mutations Conferring Resistance to Nucleoside Reverse Transcriptase Inhibitors in Human Immunodeficiency Virus Type 1-Infected Patients in Korea

A nested PCR and direct sequencing methods were used to define human immunodeficiency virus type 1(HIV-1) reverse transcriptase codons 41 to 219 in DNA from 127 peripheral blood mononuclear cell samples obtained from 35 patients treated with nucleoside reverse transcriptase inhibitors (NRTI). The follow-up period after the initiation of NRTI therapy was 61.8 ± 31 months (mean and standard deviation). In addition to NRTI therapy, 32 of 35 patients were simultaneously treated with Korean red ginseng. The annual decrease in the CD4(+) T-cell count over 5 years was 13.2/μl. Twenty-eight (80%) of the 35 patients had mutations conferring resistance to NRTI. The frequencies of K70R, T215S/Y/F (i.e., mutation of T at codon 215 to S, Y, or F), D67N/E, K219Q, T69N/S/A, M41L, and L210W mutations conferring resistance to zidovudine were 57.6, 36.4, 36.4, 27.2, 24.2, 21.2, and 12.1%, respectively. Mutations conferring resistance to didanosine and lamivudine were detected in 2 (L74V and M184I; 14.2%) of 11 patients tested and in 4 (M184V; 57%) of 7 patients tested, respectively. In particular, the frequency of T69N/S/A increased sharply after more than 48 months of zidovudine monotherapy. However, Q151M was not detected. As the first report on the frequency of NRTI resistance mutations in Korea, our data suggest that genotypic antiretroviral drug testing should be considered for the design of better drug regimens to improve the management of HIV-1-infected patients