I1307K APC gene variant and the risk for colorectal neoplasia: no clinical implication and no phenotype modification by lifestyle risk factors

Hana Strul1, 2, Erez Birenbaum1, 2, Myra Gartner1, Eli Eljadeff4, Revital Kariv2, Yonathan Eljadeff4, Dina Kazanov1, Ludmila Strier 1, Andre Keidar3, Yehudit Knaani1, 2, Yaara Degani1, 2, Hadas Sobol-Drori1, Zamir Halpern2, Nadir Arber1,2.

Gastrointestinal Oncology Unit1, Departments of Gastroenterology2 and Surgery B3, Tel-Aviv Sourasky Medical Center and Haifa Technion Institute4, Israel.

Background: APC gene variant has been designated as a pre-mutation leading to higher risk for colorectal cancer (CRC) in Ashkenazi Jews. The clinical importance of this variant in determining the risk for CRC and whether it merits a special approach for carriers is unclear.

Aims: 1) To prospectively assess the clinical implication of this polymorphism in Israeli Jews at average and high risk for CRC.

2) To examine lifestyle factors that may alter the phenotypic expression of I1307K.

Methods: 1370 consecutive subjects were stratified into average and high risk groups. DNA was amplified by PCR. The primers were designed to detect the I1307K.

Results: I1307K was found in 7.1% (9.1% among Ashkenazi and 1.7% among non-Ashkenazi Jews). The relative risk (RR) for colonic neoplasia in carriers was 1.3. The carrier rate was 8.0% and 9.5% in average and high risk Ashkenazim, respectively (p=0.58). Age, gender and histopathological features of neoplasia did not differ between carriers and non-carriers. Lifestyle risk factors (smoking, alcohol consumption, high BMI, low physical activity and vitamins intake) did not affect CRC risk in the carriers.

Conclusions: In contrast to earlier reports, I1307K harbors a minor RR of 1.3 for CRC. It is inferior to other acceptable clinical markers such as personal and family history of CRC. Its combination with established well-known lifestyle modifiers does not contribute in the clinical assessment of these average and high-risk carriers. I1307K is not an efficient marker for CRC risk and it does not necessitate intensified screening and surveillance modalities.

Immunotherapy of human colorectal cancer (CRC) hepatic metastases by BAT monoclonal antibody in nude mice

Britta Hardy, Sara Morgenstern, Annat Raiter, Galina Rodionov and Yaron Niv

Felsenstein Medical Research Center, Departments of Pathology and Gastroenterology, Tel-Aviv University School of Medicine, Rabin Medical Center, Beilinson campus, Petah Tikva, and CureTech LTD Yavneh, Israel.

Introduction: CRC becomes life threatening when metastasizes to the liver. We have previously reported that BAT monoclonal antibody is an immune modulating antibody that manifests anti tumor properties. (Cancer Res. 1994;54:5793).

Aim: In this study we present the efficacy of BAT treatment of human CRC in nude mice for prevention of hepatic metastases.

Methods: BAT was developed and produced as previously described. LIM6 and HM7 are sub-clones of the human CRC cell line LS174T, selected for high mucin synthesis and metastatic potential. The cells were injected into the spleen of anesthetized nude mice. Low dose of BAT was administered 12 days later and mice were sacrificed 35 days post inoculation. The livers weighed, and the number of metastatic nodules counted. Liver tissue was processed for histology and immuno-histochemistry.

Results: BAT prevented LIM-6 xenografts development. The average weight of xenografts from treated mice and controls were 0.14±0.17gr and 0.98±1.12gr, respectively (P=0.004). HM7 cells resulted in large number of bulky liver metastases that could be prevented by a single administration of BAT. This was manifested by the reduction of liver weight from 3.38±0.5gr in non-treated mice to 1.51±0.1 and 1.43±0.1gr in BAT and HuBAT treated mice. A similar decrease was found in the number of metastases, from 134.5±34 to 8.36±3 and 4.88±2. BAT prevented the accumulation of lymphocytes near the tumor.

Conclusion: Treatment with BAT was efficient for prevention of liver metastases in the murine model. The role of lymphocyte may be related to outcome and suggests a mechanism for BAT therapy.

Effect of monastrol, an inhibitor of a mitotic kinesin, on cells from A GASTRIC CARCINOMA CELL LINE

Ilit Horshi#, Alexander Fich* and Larisa Gheber#*

Departments of Gastroenterology* and Clinical Biochemistry#, Faculty of the Health Sciences and Soroka Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel

Background: Mitotic chromosome segregation is an essential process, accomplished by the spindle. Recent studies have shown that kinesin-related proteins play essential roles in mediating spindle dynamics. In human cells a mitotic kinesin HsEg5 was found to be a major factor in spindle dynamics.

Recently a small molecule, monastrol, was found to be a highly specific inhibitor of the mitotic kinesin Eg5, in Xenopus cells. The effect of monastrol on human cells has not been studied. Our long-term objective is to investigate the possibility of specific inhibition of a human mitotic kinesin as a potential anticancer agent.

Aim: To examine the effect of monastrol on human cells from a gastric carcinoma cell line.

Methods: AGS cells were grown under standard conditions. Cell growth was examined by trypan blue staining. Cell cycle was analyzed by flow cytometry. Apoptosis was demonstrated by acridine orange and ethidium bromide staining and by JC-1 dye. Spindle structure was demonstrated by immunostaining.

Results: Monastrol inhibits AGS cell growth in a dose-dependent manner. Exposure to 100 µM monastrol for 24, 48 and 72h causes G2/M cell-cycle arrest. The 24 h monastrol-induced arrest of AGS cells is reversible, while 48h and 72h of exposure to monastrol leads to irreversible G2/M arrest. After 48h of monastrol treatment about 50% of AGS cells are undergoing apoptosis.

Conclusions: Monastrol inhibits AGS cell growth by imposing G2/M cell cycle arrest. Long-term treatment with monastrol, causes irreversible G2/M arrest of AGS cells and cell death, probably by an apoptotic pathway.

nkt lymphocytes mediate Suppression of hepatocellular carcinoma growth via tumor antigens pulsed dendritic cells

Oren Shibolet, Ruslana Alper, Lidia Zolotarov, Yaron Ilan. Liver Unit, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.

Background: NKT lymphocytes and Dendritic cells (DC) were sHown to play a role in immune regulation of anti tumor response. Aims: To evaluate the anti tumor effect of NKT lymphocytes and DC pulsed with tumor or viral-associated antigens in HBV-expressing HCC in mice. Methods: Balb/C mice were sublethally irradiated and transplanted with Hep3b HCC cell line, followed by transplantation of naive splenocytes. DC were separated using CD11c beads and pulsed with HBV envelope proteins (group A), HCC cell lysate (group B), or BSA (control group C). Mice were followed for survival, and tumor size. To determine the mechanism of the anti tumor effect, FACS analysis for T cells sub-populations, ELISPOT and T cell proliferation assays, and cytokine analysis were performed. Results: Treatment with tumor-associated antigens-pulsed DC significantly improved survival (40% and 50% as compared with 0% in groups A, B, and control group C, respectively, p<0.005). Tumor size decreased to 12.8±0.4 and 0, compared with 60.4±0.9 mm3, in groups A, B, and control group C, respectively (p<0.005). A significant increase in NKT and CD8+ along with a decrease in CD4+ lymphocytes was achieved in the treated groups. A significant increase in HBV-specific-IFNg spot-forming-colonies, and T-cell stimulation index was evident in treated mice. IFNg and IL-12 serum levels significantly increased in treated groups. Conclusions: Tumor antigen pulsed DC effectively suppressed the growth of hepatocellular carcinoma in mice. This effect was mediated via enhancement of the anti-tumor/anti-viral specific IFNg production, and may be mediated via enhanced NKT and CD8+ lymphocyte function.

FAMILIAL JUVENILE POLYPOSIS AT THE TEL AVIV MEDICAL CENTER:

DEMOGRAPHIC AND CLINICAL FEATURES

Paul Rozen1,2, Ziona Samuel1, Eli Brazowski2,3, Zamir Halpern1,2, Jacob Rattan1,2, Markus Jakubowicz1

1Gastroenterology Dept., 2Pathology Dept., Tel Aviv Medical Center and 3Tel Aviv University Medical School, Israel

Background: Familial juvenile polyposis (JP) is an uncommon, but widespread genetic disorder that develops multiple gastrointestinal, but mainly colonic juvenile polyps and, if untreated, to large bowel or other gastrointestinal cancer. Little is known about its occurrence and characteristics in the Israeli population. Aims: To evaluate JP prevalence, phenotypic manifestations and compliance for diagnosis and follow-up in our registry. Methods: Since 1993 our JP patients were registered, followed-up before and/or after surgery and their families encouraged to have endoscopic screening and treatment. Results: 10 pedigrees were identified, all Jewish, but dissimilar to the general population as only 1 was Ashkenazi, 6 Sepharadi and 3 Oriental. 139 first-degree relatives were at-risk for JP (62 (45%) had JP or cancer), 56 (40.3%) available for follow-up & 35 entered the registry. 71% of those registered reported rectal bleeding, 31% had 20-100 colonic polyps, <20 polyps in 40%; multiple gastric polyps in 1 patient. Cancer occurred in 22.9% (6 colonic, 2 gastric) before JP diagnosis or during follow-up elsewhere or non-compliance, but 1 gastric cancer developed during our follow-up. In 46% the initial diagnosis was incorrect. Compliance for evaluation and follow-up of pedigree members and individual FAP patients was inadequate in 20% and 26% respectively. Conclusions: JP occurs in the Israeli Jewish population but not at the expected proportion in the Ashkenazi population, it is often misdiagnosed & inadequately recognized in non-Jews. The inadequate compliance for screening and follow-up needs to be addressed by educating the public, health care workers and Health Insurers.

MOLECULAR ANALYSIS OF THE APC GENE IN 71 ISRAELI FAMILIES: 17 NOVEL MUTATIONS

Avi Orr-Urtreger1,4, Yuval Yaron1,4, Tova Naiman1, Dani Bercovich1, Nancy Gavert2, Cyril Legum1,4, Paul Rozen3,4, Zamir Halpern3,4, Ruth Shomrat1

1Genetic Institute & Prenatal Diagnosis Unit, 2Department of Surgery B, 3Consultative Service for Hereditary Cancer, Department of Gastroenterology, Tel Aviv Sourasky Medical Center, Israel, affiliated to 4Sackler Faculty of Medicine, Tel Aviv University, Israel

Background: There is little known about germ-line APC gene mutations in Israeli familial adenomatous polyposis (FAP) families.

Methods: 71 Israeli families were referred for APC molecular analysis by the protein truncation test (PTT) of exon 15, & if negative, by direct sequencing of exon 1 to 14.

Results: Mutations were found in 36 (50.7%) probands. Mutation detection rates depended on pattern of referral, so that in 40 probands referred from the Service for Hereditary Cancer the mutation detection rate was 70%, whereas among 31 probands referred by other gastroenterologists the detection rate was significantly lower (25.8%). Of the 36 mutations detected, 21 were within exon 15 (58.3%), 13 (36.2%) within exons 1 to 14 & 2 (5.5%) were newly described splicing mutations in introns 9 & 14. A relatively high mutation rate was detected in exon 9 (6/36, 16.7%), five of them newly described; altogether 17 new mutations. Within patients of Ashkenazi & non-Ashkenazi origin, there was no significant difference in the mutation detection rate or distribution of mutations within the APC gene. No founder mutation was detected.

Conclusions: Our data confirm that higher detection rates may be expected in patients referred by clinical services specializing in hereditary colon cancer. These results further underscore the importance of complete analysis of all exons & exon/intron boundaries by utilizing a new faster & accurate methodology, a dHPLC, in order to achieve maximal detection rate in patients suspected for FAP.

The role of abdominal CT in the evaluation of patients with asymptomatic iron deficiency anemia- a prospective study.

Eva Niv 1, M.D., Avishay Elis 1, M.D., Rivka Zissin 2, M.D.,Timna Naftali 3, M.D., Ben-Zion Novis 3, M.D. and Michael Lishner 1, M.D.

From the Departments of Medicine 1, Diagnostic Imaging 2 and Gastroenterology 3, Sapir Medical Center, Kfar-Saba and Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

Background and aim

Despite the increasing use of computed tomography(CT) for abdominal imaging, its role in the evaluation of iron deficiency anemia(IDA) has not been studied to date. Our aim was to compare the yield of abdominal CT with gastrointestinal(GI) tract endoscopies in patients with asymptomatic IDA.

Methods

Forty eight patients older then 50 years with asymptomatic IDA underwent colonoscopy, gastroscopy and abdominal CT .The radiologist and gastroenterologists were unaware of each other’s findings. The results of these tests were compared .

Results

In 14 patients (29.2 %) a malignancy was responsible for the IDA. CT detected all malignant tumors, which were found at endoscopy. In addition, it identified one case of colon carcinoma, which was missed by colonoscopy, and one small intestinal tumor. There was one false positive CT and one incidental finding of a prostatic carcinoma. CT did not detect benign superficial mucosal pathologies.

Conclusions

This prospective study shows that CT has an excellent concordance with endoscopies in the detection of GI tract malignancies, a frequent and important cause of asymptomatic IDA in patients >50 years old. Therefore, it should have an important role in the evaluation of such patients who cannot or refuse to undergo invasive diagnostic procedures.

Colonoscopic Perforations- Incidence and Management: 8 Years` Experience.

Hagit Tulchinsky, MD, Osnat Madhala, MD, Shlomo Lelckuk, MD, Yaron Niv, MD,

Departments of Surgery B and Gastroenterology, Rabin Medical Center, Beilinson Campus, Petah Tiqva and Sackler Faculty of Medicine, Tel Aviv University

Background: Colonoscopy is the best method for the diagnosis, treatment and follow-up of colorectal pathologies, but as an invasive procedure it carries major risks such as hemorrhage, perforation and death.

Objective: To review the experience of a major medical teaching center with diagnostic and therapeutic colonoscopies and to assess the incidence and management of related colonic perforations.

Methods: All colonoscopies performed between January 1994 and December 2001 were studied. Data on patients, colonoscopic reports and procedure-related complications were collected from the departmental computerized database. The medical records of the patients with post procedural colonic perforation were reviewed.

Results: A total of 12,067 colonoscopies were performed during the 8 years of the study. Seven colonoscopic perforations (4 females, 3 males) were diagnosed (0.058%). Five occurred after diagnostic and two after therapeutic colonoscopy. Most were treated surgically. No deaths were reported.

Conclusions: primary repair due to colonoscopic perforations can be done safely with low morbidity and mortality in a selected group of patients, unless there is a colonic pathology that necessitates resection.

Consensus and Controversy in the Management of Pediatric Crohn’s Disease: An International Survey

Arie Levine M.D1, Tamir Milo MD1, Hans Buller M.D2,James Markowitz M.D3

Pediatric Gastroenterology Unit, E.Wolfson Medical Center , Holon,Israel1, Sophia Children’s Hospital, Rotterdam, The Netherlands2, North Shore University Hospital, Manhasset, New York, USA3

Background: Treatment options for Crohn’s disease (CD) have expanded, but the use in clinical practice of some of these options remain controversial We therefore attempted to evaluate current trends in treatment, and assess areas of consensus or controversy.

Methods: An international survey of certified pediatric gastroenterologists by e-mail questionnaire, which attempted to evaluate the treatment of active disease, attitudes towards four types of therapy, and role of testing for osteopenia and 6 thioguanine levels.

Results: 167 physicians from the USA, Canada, Western Europe, and Israel were included. The majority of North American physicians (71%) prefer use of conventional steroids and AZA before nutritional therapy or budesonide in mild to moderate active disease, versus 21% of Western Europeans (p<0.001). West Europeans prefer nutritional therapy followed by budesonide or steroids for non severe disease. Only 4% of North American gastroenterologists use nutritional therapy frequently, versus 62% of their West European colleagues (p<0.001). Infliximab was thought to be effective in steroid unresponsive disease by almost all physicians surveyed, though its efficacy as a maintenance therapy was rated higher by North American physicians in comparison to European or Israeli colleagues (p<0.01). Bone mineral density is routinely evaluated by about 45% of physicians in Europe and North America.

Conclusions: Attitudes toward current therapies influence how patients are managed, and vary significantly by region, with North Americans strongly favoring corticosteroids followed by immunomodulatory therapy, and Europeans favoring nutritional therapy or budesonide and the avoidance of conventional corticosteroids.