P53, cyclin D1 and Rb genes expression changes in esophageal squamous cell carcinoma in iran

kinase activity of PKD2. Wild type PKD2 was mainly localized in the cytoplasm. Upon addition of gastrin, PKD2 was detectable in the perinuclear region as well as in the nucleus. Nuclear translocation of PKD2 required an intact Zinc finger domain, kinase activity as well as the presence of gastrin. In conclusion, PKD2 is a serine threonine kinase which is activated and translocates to the nucleus in response to gastrin in human gastric cancer cells suggesting a potential role of this kinase as a novel mediator of transcriptional regulation by gastrin.

in gastric cells but show that the region -871/-1 bp ( + 1 corresponds to the transhtion stan site) is relevant for Cdx2 expression in gastric cells. This region has a consensus binding site for the transcription factor OCT1, which is involved in Cdx2 expression in intestinal cells. The region -1251A1 bp shows putative repressor binding sites. In conclusion, our results show that Cdxl and Cdx2 are aberrantly expressed in gastric carcinoma cell lines, similarly to previous observations in intestinal metaplasia and gastric carcinomas. Promoter studies suggest that a transcription factor that is involved in the expression of Cdx2 in intestinal cells, OCT-l, might be involved in the regulation of this gene in gastric cell lines.

M1033 ZD1839 (Iressa) inhibits anticancer-drug-induced activation of the EGF/EGFR autocrine loop and IL-8 production in gastric cancer cells Osamu Kishida, Yoshiji Miyazaki, Miyuki Toyota, Tamana Miyazaki, Kenji Watabe, Tatsuya Kiyohara, Shnsaku Tsutsui, Yasuhisa Shinomura, Yuji Matsuzawa

M1036

P53,Cyclin D1 and Rb Genes Expression Changes in Esophageal Squamous Cell Carcinoma in Iran Seyed Javad Mirhassani Moghaddam, Mohammad All Daneshmand, Arezoo Aghakhani, Mohammad Omid Edrissian, Mohammad Reza Zali

Backgrounds & Aims: Several anticancer drugs are known to produce reactive oxygen species, which mediate a vanety of cellular reactions. The present study was performed to determine the effects of SN38 (an active metabolite of CPT-11) and CDDP on epidermal growth factor receptor (EGFR) activation and interleukin-8 (IL-8) expression in gastric cancer cells, and to examine if ZD1839, an EGFR-TKI (EGFR tyrosine kinase inhibitor), abrogates these reactions. Methods: MKN28 and AGS gastric cancer cells were treated with SN38 or CDDP. The expression of heparin-binding EGF-like growth factor (HB-EGF), amphiregulin (AR), transforming growth factor a (TGF-a) and 1L-8 were evaluated by Northern blotting and/or ELISA. Tyrosine phosphorylation of EGFR and activation of AP-1 and NF-KB were determined by Western blotting and electrophoretic mobility shift assay, respectively. Results: Both SN38 and CDDP induced tyrosine phosphorylation of EGFR within 30 rain, followed by the expression of HB-EGF, AR and TGF-cr in a time-dependent manner. These drugs also activated AP-1 and NF-KB, which are the critical transcription factors for IL-8, and induced the expression of IL-8 mRNA and protein. Overall, SN-38 was more potent in inducing these reactions than CDDP. ZD1839 (1 IzM) abrogated SN38-induced tyrosine phosphorylation of EGFR, expression of EGF-like growth factors, activation of AP-1 and NF-KB and production of 1L-8 Conclusions: Anticancer drugs are capable of activating the EGF/EGFR autocrine loop, followed by activation of AP-1 and NF-KB, which mediate induction of IL-8, an angiogenic factor, in gastric cancer cells. Because ZD1839 abrogates these reactions, the combination of conventional anticancer drugs with ZD1839 may be a reasonable therapeutic approach in certain gastric cancers

Background: Esophageal squamous cell carcinoma is the third most common gastrointestinal malignancy and is ranked among the first ten cancers worldwide. The effect of some genes especially those involved in cell cycle regulation have been shown in development of the disease. We studied expression changes of p53, Cyclin D1 and Rb genes in our samples. Methods: The paraffin--embedded tissue samples of 135 patients (68 male and 67 female) with documented esophageal sqnamons cell carcinoma were collected from 22 pathology centers in Tehran, during a period of 3 years (1999 -2001).Using immunohistochemistry method (Avidin-Biotin-Peroxidase),they were stained for detection of p53,Cyclin D1 and Rb proteins. The results were expressed as frequency and odds ratio. Results: The mean -+SD age of patients was 57.39 +_ 10.66 years old. Sixty (44.4%), 66(48.9%), and 60(44.4%)patients were positive for p53, Rb and Cyclin D1, respectively. Among those with positive p53, 36(60%) were Rb positive and 38(63.3%) Cyclin D1 positive, while among those with negative p53, 30(40%) were Rb positive and 22(29.3%) Cyclin D1 positive. Comparing p53 positive cases with the negative ones, the former group showed a higher (2.25 times) risk of being positive for Rb gena. This figure was 4.16 for Cyclin D1. Among those with positive Cyclin D1, the risk of being positive for Rb was 7.71 times greater than negative cases for this gene. We could find no significant difference between p53, Cyclin D1 and Rb gene expression changes and the degree of tumor differentiation using MannWhitney in each sample (p>0.5). Conclusion: Like other parts of the world, the development of mutation in p53 ,Cyclin D 1 and Rb genes appears to have a key role in the carcinopathogenesis of esophageal squamons cell carcinoma in Iran. Also a significant association between the mutations of these three genes during development of this cancer is likely.

M1034 Selective Cox-2 Inhibitor Down-Regulates In Human Gastric Cancer Genes Promoting Cell Growth: Global Gene Expression by DNA Microarray Study Clarke A Hilbig, John Chai, Andrzej S. Tamawski

M1037 Decay-Accelerating Factor as a Surface Marker for Specialized Columnar Epithelium in Barrett's Esophagus Sakiko Hiraoka, Motowo Mizuno, Ryou Terada, Hiroaki Okazaki, Shinichirou Hori, Chiho Makidono, Tatsuya Toyokawa, Ryuta Takenaka, Susumu Take, Kazuhide Yamamoto, Hiroyuki Okada, Yasushi Shiratori

NSAIDs, including COX-2 selective agents, inhibit the growth of gastrointestinal cancers, but the mechanisms of this inhibitory action, the genes involved and the signaling pathways are not fully understood Furthermore, little is known regarding the effects of COX-2 inhibition on human gastric cancer. Using cDNA microarray (gene chip) technology, we studied how selective COX-2 inhibitor alters expression of genes known to regulate cell growth and intracelhilar signaling. Methods: Human gastric cancer AGS cell line was treated with either placebo or COX-2 selective inhibitor NS-398 (0.01raM) for 1 and 5 hours. Studies: 1) Affymetrix Human Focus gene arrays containing cDNA from approximately 8700 genes were used and the data were analyzed via Silicon Genetics' Gene Spring Sequence Database. 2) Expression of selected proteins was assayed using RayBio Human Cytokine Array. 3) Cell death was determined by the TUNEL method. Results: TUNEL staining demonstrated that NS-398 (0.1raM) induced apoptosis in approximately 27% and 31% of AGS cells at 1 and 5 hours respectively. NS-398 treatment for 1 hour significantly downregulated mRNA of pro-growth genes such as: RRAD/ RAS-associated (5 fold), EREG/ epiregulin involved in EGF signaling (5 fold), FOLR3/folate receptor (4 fold), EPSIN/mitotic cycle control (5 fold), and ANGPTL4/hepatic angiopoietin-related protein (3 fold). NS-398 treatment at 5 hours significantly down-regulated mRNA of pro-growth genes such as: DTR/ EGF-like growth factor (20 fold), EGR-1 and -3/early growth response (15 fold and 8 fold), T1EG/TGF-[3 inducible early growth response (4 fold), SGKL/cytokine-independent survival kinase (5 fold), and COX-2 (11 fold). In addition, NS-398 activated several other clusters of genes involved in cell cycle regulation and signaling. Conclusions: 1) COX-2 selective inhibition induces apoptosis in human gastric cancer. 2) This action is related to inhibition of several pathways involved in cell growth and intracenular signaling, including mitogenic growth factors, G-protein signal transduction, DNA binding, mitosis and prostaglandin synthesis. 3) COX-2 inhibitors, in addition to blocking prostaglandin synthesis may directly affect numerous genes involved in cell growth and signaling.

Background and aims: Barrett's esophagus is a condition in which the normal squamous lining of the distal esophagus is replaced by the columnar epithelium consisting of the intestinal metaplasia with goblet cells, i.e., specialized columnar epithelium (SCE). SCE is recognized as the major risk factor for development of esophageal adenocarcinoma. We have previously shown that surface expression of decay-accelerating factor (DAF), a complementregulatory protein, is markedly enhanced in intestinal metaplasia of the gastric mucosa (Histopathology 2002;40:339-47). In this study, we examined an expression of DAF in SCE and analyzed if DAF can be a marker for SCE in Barrett's esophagus. Methods: Fifiy-three endoscopic biopsy specimens were obtained from the area of suspected esophageal columnar mucosa of 45 patients whose squamocolumnar junction was above the level of the esophagogastric junction. SCE was defined by the presence of acid mucin-containing goblet cells using alcian blue (pH 2.5) stain. Tissue specimens were analyzed immunohistochemically for expression of complement-regulatory proteins; DAF, CD59 and membrane cofactor protein. Laser capture microdissection and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to examine DAF mRNA expression in SCE. Results: SCE was identified in 12 of 53 biopsy specimens. DAF intensely stained on the apical surface of SCE in all the 12 specimens, whereas DAF staining was negligible in the other specimens with SCE.negative columnar epithelium (p