This study consisted of 2 aims: (i) to determine genes associated with hepatocellular carcinoma (HCC) by microarray analysis; and (ii) to evaluate the clinicopathological significance of human ubiquitin-conjugating enzyme E2C (Ube2c) found to be overexpressed in HCC from microarray analysis. Laser microdissection and cDNA-microarray were performed to identify genes associated with HCC. We then focused on the Ube2c gene. Using realtime quantitative reverse transcription-polymerase chain reaction (RT-PCR), Ube2c expression status and clinicopathological significance were studied in 65 clinical HCC samples. A number of genes upregulated in HCC cells compared to noncancerous liver cells were identified, one of which was the Ube2c gene. Ube2c gene expression in the cancer tissue was higher than in the corresponding noncancerous tissue in 62 of the 65 cases (95.4%, p < 0.01). Tumors with high Ube2c expression showed higher frequencies of tumor invasion to capsular formation (fc-inf), invasion to portal vein (vp) and tumor de-differentiation (p < 0.05). Patients with high Ube2c expression also showed significantly worse disease-free survival rates than those with low Ube2c expression (p < 0.01). In addition, Ube2c expression was found to be an independent prognostic factor for disease-free survival rate in multivariate analysis. We identified differentially expressed genes between HCC and normal liver tissues. Of those, the Ube2c gene appeared to be associated with HCC progression, and may be useful as a prognostic indicator for HCC patients. ' 2007 Wiley-Liss, Inc.

No abstract

Up-regulation of the IL-1-IL-6 network stimulates systemic expression of C-reactive protein (CRP). This cytokine network system plays a pivotal role in inducing angiogenic growth factors in intestinal mucosa. Serum CRP level and tissue concentrations of cytokines in colorectal cancer patients were determined and an in vitro model was employed to determine the time course of induction of IL-6 in Caco-2 cells. Increased serum CRP was associated with recurrent disease and shorter survival time. Intense surgical stress and the presence of an acute phase reactant were independently associated with overexpression of IL-6 in the tumor. Enhanced IL-6 protein expression in Caco-2 cells induced by the initial treatment with IL-1beta or lipopolysaccharide could be abrogated by additional presupplementation of IL-1ra. The presence of an acute phase reactant reflects uncontrolled up-regulation of the local IL-1-IL-6 network system in the tumor, which may enhance the survival and proliferation of remnant cancer cells after tumor resection.

We identified radiation-related genes in colorectal cancer and demonstrated that PTMA may play an important role in radiosensitivity. Our findings suggest that PTMA may be a novel marker for predicting the effectiveness of radiotherapy in clinical cases.

No abstract

To evaluate the optimal schedule of 5-fluorouracil (5-FU) radiosensitization in rectal cancer, we investigated the interaction between radiation and several doses of 5-FU on colon cancer cell lines based on pharmacokinetics of oral fluoropyrimidine. Cellular cytotoxicity in colon cancer cell lines, LoVo, WiDr and Caco-2 was determined, using a WST-8 colorimetric assay, after 24 h exposure to several concentrations of 5-FU and a radiation dose of 5 Gy. Cells were exposed to 5-FU 24 and 0 h before radiation. 5-FU doses were classified into three groups: uracil-tegafur (0.01-0.1 μM), S-1 (0.1-1.0 μM) and pharmacokinetic modulating chemotherapy (0.1-10 μM). In addition, the effect of 5-FU on the steadystate levels of a human excision repair cross-complementing 1 gene and cell cycle distribution were examined. Regardless of time of 5-FU exposure, all cell growth was significantly inhibited in a dose-dependent manner. In Caco-2 cells, the cytotoxicity of radiation followed by 5-FU was significantly greater than that of 5-FU followed by radiation, unlike in the other cell lines. The growth inhibitory effect of radiation followed by 5-FU increased in a dose-dependent manner to reach a plateau at S-1 doses in all cell lines. In cell cycle distribution, 5-FU exposure for 24 h increased the S phase fraction in a dose-dependent manner. RT-PCR showed that 5-FU post-treatment graduallly inhibited mRNA expression of ERCC1, which may affect recombination repair efficiency, accounting for the higher tumor sensitivity. Oral fluoropyrimidines, like S-1, that can maintain a constant level of 5-FU may be an acceptable alternative radiosensitizer to protracted 5-FU infusion, when the aim of neoadjuvant chemoradiotherapy for rectal cancer is locoregional control.

No abstract

The range of optimal concentration for PXL pretreatment was 0.01-0.1 microM in these cells. Two major mechanisms of radio-enhancement are suggested: (1) PXL induces G2/M arrest leading to increased DNA damage after radiation, which results in mitotic death, and (2) PXL suppresses the expression of radiation-induced DNA repair molecules and angiogenesis factors, resulting in inhibition of cell growth and cell death.