Catenin phosphorylation in Barrett's esophagus

A1414 AGA ABSTRACTS

GASTROENTEROLOGY Vol.

6422 IMMUNOPHENOTIPIC STUDY OF EPITHELIAL GASTRIC DYSPLASIA (EGD). Gianni Testino, Matteo Cornaggia, Daniela Gada, Maurizio Valentini, Gastroenterology Unit, S Martino Hasp, Genova, Italy; Dept of Human Pathology, Univ of Varese, Varese, Italy. 70 cases of low grade dysplasia (LGD) (mean age 56) and 50 cases of high grade dysplasia (HGD) (mean age 58) were retrospectively selected and investigated using Abs against pepsinogen C (PC), gastric foveolar Ml, intestinal CAR5 and pancreatic DUPAN2 Ags. Gastric biopsy specimens obtained in the course of gastroscopy were studied for dyspepsia: for each patients, at least 8 specimens (range 4-16) were obtained. EGD diagnosis was done by experienced pathologists (MC,DG) with a good interobserver agreement. The clinical outcome subdivision of EGD was made using the criteria of Rugge: association with GC (AGC), progression to GC within I year (PGC), persistence (P) and regression (R). Results: the results of the immunohistochemical investigation are reported in Table I. The coexpression of the four immunohistochemical markers and the correlation with the clinical behaviour (CB) of the lesions have been effected: gastric markers (GM): PC+Ml; enteropancreatic markers (EPM): CAR5+DUPAN2; gastric and enteropancreatic markers (GEPM): PC+Ml +CAR5+DUPAN2; no markers expression (NM). CB: LGD AGC 4(5.7%), PGC 2(2.9%), P 19(27.1%), R 45(64.3%); HGD AGC 33(66%), PGC 4(8%), P 5(10%), R 8(16%). Coexpression: LGD GM 5(7.1%), EPM II (15.7%-6 cases AGCI PGC), GEPM 54(77.1%); HGD GM 2(4%-2 cases PIR), EPM 34(68%), GEPM 10(20%-11 cases PIR), NM 4(8%). Conclusions: I)EGD is characterized by a progressive reduction of GM with a progressive expression of enteropancreatic antigens, 2) LGD are characterized by a frequent expression of MI and CAR5, 3)HGD are characterized by a frequent expression ofCAR5 and DUPAN2, 4) LGD are characterized by a frequent GEPM coexpression, while HGD by a frequent EPM coexpression or by NM, 5) LGD with greater EPM are progressed more frequently towards GC, while HGD with lower EPM are in the group with persisted or regressed cases. Table I-

PGC M1 CAR·5 DU·PAN·2

LGD

HGD

1(14%) 65(92.9%) 68(97.1%) 19(27%)

1(2%) 10(20%) 38(76%) 22(44%)

n.s, p=0.2 x 10(·6) p=0.04 p=004

6423 TUMOR REDUCTION SURGERY FOLLOWED BY ALLOGENEIC STEM CELL TRANSPLANTATION. A TREATMENT FOR DIS· SEMINATED GASTROINTESTINAL CANCER? Anders Thorne, Henrik Zetterquist, Patrik Hentchke, John Mattsson, Mehmet Uzunel, Johan Aschan, Susanne Ohman, Olle Ringden, Karolinska Inst, S-141 86 Huddinge, Sweden; Dept of Surg, Huddinge, Sweden; Ctr of Allogeneic Cell Transplantation, Huddinge, Sweden. Allogeneic stemcell transplantation (ASCT) is an established treatment of malignant haematological diseases such as leukemia and Iymfoma. ASCT has a well known anti-tumor (Graft-vs-Tumor) effect but also potential serious side effects (Graft-vs-Host disease and infections. With a modified ASCT protocol (mASCT), it is possible to reduce the side-effects with preserved anti-tumor effect. In mASCT, a mild immunosupressive conditioning protocol using Fludarabin and total body irradiation (2 Gy), is followed by peripheral stemcell infusion from a HLA-identical sibling. The stemcells are harvested from the peripheral blood circulation of the donor following 5 days s.c.administration of granulocyte colony stimulating factor (G-CSF). The purpose of the study is to find evidence of an anti-tumor effect of mASCT in patients with disseminated gastrointestinal cancer. Patients with identical histopathology and tumor burden but without a HLA-identical sibling serve as controls. The presence of stemcells from the donor (mixed chimerism) is monitored using molecular techniques. The effect of the mASCT treatment is monitored with repeated CT, MRI and/or CEA, CA 19-9 and CA 50 levels in serum. So far, II patients has been evaluated for a possible mASCT. Six of them had no HLAidentical sibling and were thus not subjects for mASCT. Two patients has been transplanted to date and another patient will undergo mACST in the near future. The first patient, who had a non-resectable lung metastasis and disseminated lymphnode involvement following a colorectal cancer (CRC) has undergone mASCT without complications. Two months post transplantation, >50% reduction of lymphnode metastasis is demonstrated by CT. The second patient with persistent elevated tumor markers after liver resection of CRC metastasis was recently transplanted without complications in an out-patient manner but the effect of the mASCT treatment is to

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early to evaluate. The third patient, who is suffering from liver metastasis from CRC is scheduled for tumor reduction liver surgery and mASCT. Another two patients with CRC and resected liver metastasis are potential candidates for mASCT if they demonstrate persistent elevated tumor markers on the follow ups. Concept and protocols as well as our latest results of disseminated gastrointestinal cancer with tumor reduction surgery and mASCT will be presented.

6424 IMMUNOBLOT ANALYSIS OF THE E-CADHERIN-CATENIN AND THE ADENOMATOUS POLYPOSIS COLI-CATENIN COM· PLEXES IN COLONIC CANCER CELL LINES. Muneta Tomizawa, Masao Noda, Shoji Mitsufuji, Hiroyuki Sugihara, Tadashi Kodama, Kei Kashima, Takanori Hattori, Kyoto Prefectural Univ of Medicine, Kyoto, Japan; Shiga Univ of Med Sci, Otsu, Japan. Background: The cadherin-catenin complex is a key component of the adherens junction, and its reduced expression has been shown to be associated with tumor differentiation, infiltrative growth and lymph node involvement in colonic adenocarcinomas. Furthermore, /3-catenin can bind the adenomatous polyposis coli (APC) gene product, and may regulate cell proliferation interacting with nuclear transcription factors TCFILEF. In this study, we evaluated, quantitatively, the expression of E-cadherin concomitantly with (l', /3, v-catenin. p120, and APC in a panel of colonic cancer cell lines. Methods: Human colonic cancer cell lines Cac02, HT29, LSI74T, SWI222 (well or moderately differentiated adenocarcinoma), HCTI16, SW480 and SW620 (poorly differentiated adenocarcinoma) were cultured in DMEM supplemented with 10% fetal bovine serum. Cell lysates were fractionated on SDS-polyacrylamide gel and transferred to nitrocellulose membrane. The proteins of interest were detected using monoclonal antibodies followed by a HRP-labelled species specific secondary antibody and developed using ECL chemiluminescence. Results: Normal E-cadherin was not detected in LS l74T, and decreased in HCTI16, SW480 and SW620. The normal 94-kilodalton band of /3-catenin was found in all cell lines, and the expression was up-regulated in LS 174T, SW1222, SW480 and SW620. o- and ')'- catenins were decreased in LSI74T, HCTlI6, SW480 and SW620 compared to the other cell lines. As for p120, normal single band was detected in HCTll6 but extra-bands were found to various extents in other cell lines. Conclusion: The expressions of E-cadherin, (l'- and ')'-catenins showed similar patterns of intensity in each cell line, whereas /3-catenin was increased independently. The pl20 expression was mutated in all cell lines except for HCTI16 which is known to have full length APC. These findings support the direct contribution of /3-catenin and pl20 to the development and progression of colonic carcinomas.

6425 CATENIN PHOSPHORYLATION IN BARRETT'S ESOPHAGUS. Chris Tselepis, Ian Perry, Robert Hardy, Janusz A. Jankowski, Univ of Birmingham, Birmingham, United Kingdom. Barrett's esophagus is a premalignant condition which can progress to esophageal adenocarcinoma. It has previously been reported that in Barrett's esophagus there is an increase in growth factors and their receptors, such as EGF and EGFR, and that there is also an alteration in the cell-cell adhesion systems, principally a loss of E-cadherin. In this study we show nuclear localization of /3 and '}'-catenin in esophageal cancer specimens, despite APC and /3-catenin mutations being rare. Using immunoprecipitation studies on normal and diseased tissue the nuclear /3- and v-catenin are tyrosine hyper-phosphorylated and no longer bind E-cadherin and the desmosomal cadherin Dsg respectively. In cell culture studies, treating primary esophageal cultures with EGFITGF causes a change in cell morphology from epithelial to spindle shape which correlates with loss of E-cadherin, tyrosine hyper-phosphorylation and nuclear accumulation of /3-catenin. Stimulation with TNF and TGFIEGF (but not with TGFIEGF alone), resulted in y-catenin nuclear localisation and this was again correlated with a down-regulation of E-cadherin. It appears that growth factors and cytokines which are elevated in Barrett's esophagus may cause catenin phosphorylation and may signal catenins to the nucleus where they may induce oncogene expression.