Rapid and specific targeting of monoclonal antibody A33 to a colon cancer xenograft in nude mice.
Barendswaard EC. Scott AM. Divgi CR. Williams C Jr. Coplan K. Riedel E. Yao TJ. Gansow OA. Finn RD. Larson SM. Old LJ. Welt S.
Ludwig Institute for Cancer Research, Heidelberg, Victoria, Australia.
Monoclonal antibody (mAb) A33 detects a glycoprotein homogeneously expressed by > 95% of human colon cancers and by normal colon cells. The A33 antigen is not secreted or shed and after mAb A33 binds to antigen on the cell membrane, a fraction of membrane-bound mAb A33 is internalized into endosomes. Phase I 131I-mAb A33 biodistribution studies have shown consistent, specific tumor-targeting, and phase I radioimmunotherapy trials with 131I- or 125I-mAb A33 have demonstrated antitumor effects. Here we describe a nude mouse model that was established using a human colon cancer cell line, SW1222, which grows as a relatively hypovascular, invasive heterotransplant when injected i.m. Peak uptake of 131I-labeled or 111In-chelated mAb A33 was observed at 48-96 h, with a mean of 34% (SE +/- 5.0) and 46.7% (SE +/- 1.7) injected dose per gram of tumor tissue, respectively. 111In-mAb A33 was retained in tumor tissue longer than halide radioimmunoconjugates. The specificity of antibody localization was assessed using a control antibody (tumor uptake and pharmacokinetics), a control tumor, corrections for vascular antibody blood-pooling in tumor tissue, and blocking of radiolabeled mAb A33 localization by pretreating mice with excess unlabeled mAb A33. These experiments demonstrate that mAb A33 localization in tumor was specific, and they emphasize the unexpected rapidity with which the antibody localizes. Our conclusions were confirmed by immunohistochemical techniques which allowed direct visualization of localization and distribution of the humanized version of mAb A33 in tumor tissue. Furthermore, antibody doses approximating tumor-saturating doses demonstrated that a homogeneous distribution of antibody in tumor is possible. This model will be valuable for studies focusing on general physiologic aspects of antibody-to-tumor cell localization and critical as a guide to the evaluation of various A33 antibody constructs and combinations with other therapies for the treatment of colon cancer.
P21 protein expression and ras-oncogene mutations in gastric carcinoma: correlation with clinical data.
Kasper HU. Schneider-Stock R. Mellin W. Roessner A.
Department of Pathology, Otto-von-Guericke-University, Leipziger Str. 44, D-39120 Magdeburg, Germany.
Ras oncogenes coding for P21 protein are frequently involved in the carcinogenesis of various human tumours. For gastric carcinomas, the role of these oncogenes has not yet been fully understood. Forty-five primary gastric carcinomas were investigated for point mutations in the hot spot regions codon 12 and 13 of exon 1 and codon 61 of exon 2 of H-, K- and N-ras gene. PCR-SSCP technique followed by direct sequencing was used. The expression of P21 protein was analysed immunohistochemically. The results were correlated to clinicopathologic data. There were no point mutations in the genes of the ras family. The incidence of P21 protein expression was 66.7% (30 of 45 cases). This expression was more common in carcinomas of the intestinal type than in carcinomas of the diffuse type. There was no correlation with tumour size, metastasis, localisation of the tumour in the stomach, histologic type, grade of malignancy, gender, or clinical outcome of the disease. Overexpression of ras oncoproteins without point mutation seems to occur frequently in gastric carcinoma, particularly in tumours of the intestinal type. There is no prognostic impact. P21 protein expression cannot be used in a predictive staging system.
Multiple cell populations in colorectal carcinomas: analysis by 3-colour fluorescence in situ hybridization.
Greenman J. Ashman JN. Brankin V. McDonald AW. Duthie GS. Lee PW. Kerin MJ. Monson JR.
Academic Surgical Unit, University of Hull, Medical Research Laboratory, Wolfson Building, Hull, HU6 7RX, UK.
A three-colour FISH approach using centromere-specific DNA probes was used to analyse the number of chromosomes 7, 17 and 18 found within individual tumour cells and the results were correlated with total DNA ploidy determined by image analysis. FISH analysis showed a high level of heterogeneity in the majority of tumour samples with only 7 out of 44 samples having a single chromosome profile occurring in greater than 40% of the cells. Analysis of the modal chromosome number showed that a diploid 2/2/2 profile for chromosome 7, 17 and 18 respectively occurred most commonly. The DNA ploidy index for biopsies with a 2/2/2 profile varied between 0.93-2.06. No gain of chromosome was observed in the adenoma samples or Dukes A tumours but a loss of chromosome 18 was seen in 50% of these early carcinomas. A modal chromosome profile of 4/2/2 was commonly found in Dukes B and C tumours suggesting that endoreduplication with the relative loss of chromosome 17 and 18 is common in advanced cancers. The DNA ploidy index for the more advanced tumours was also variable but significantly higher than that found in the early tumours and non-tumour controls. In conclusion, this work shows that tumours are highly heterogeneous and that the majority of tumours consist of a large number of cell sub-populations with respect to the expression of chromosomes 7, 17 and 18.
Immunomodulatory properties of antineoplastic drugs administered in conjunction with GM-CSF-secreting cancer cell vaccines.
Nigam A. Yacavone RF. Zahurak ML. Johns CM. Pardoll DM. Piantadosi S. Levitsky HI. Nelson WG.
Departments of Oncology, Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Cancer cells genetically modified to secrete immunoregulatory cytokines offer great promise for human cancer treatment as tumor vaccines. However, in preclinical animal studies, large established cancer burdens have appeared difficult to eradicate with such vaccines. For example, lethally-irradiated GM-CSF-secreting CT26 colon carcinoma cell vaccine therapy tends to cure only animals bearing 1 x 10(5) wild-type CT26 cells or less. For many human cancers, antineoplastic chemotherapy can often significantly reduce systemic cancer burdens. Unfortunately, for most advanced metastatic solid organ cancers, such as cancers of the breast, colon, and prostate, antineoplastic drug treatments generally fail to effect cancer cures. Treatment regimens combining genetically-modified cancer cell vaccine therapy and antineoplastic chemotherapy have the potential to increase advanced cancer cure rates if antineoplastic drugs and drug combinations that do not inhibit vaccine-induced immune responses can be identified. To assess the potential immunomodulatory properties of commonly-used antineoplastic drugs that might be used in combination with cancer vaccine treatments, we studied the effects of the drugs on antitumor immune responses manifest by animals receiving lethally-irradiated GM-CSF-secreting CT26 cell vaccines. Immunomodulatory properties of the antineoplastic drugs were evaluated i) by monitoring drug effects on the generation of tumor-specific CD8+ cytotoxic T-lymphocytes (CTLs) in response to GM-CSF-secreting CT26 vaccine administration, ii) by determining drug effects on the resistance of vaccinated animals to subsequent challenge with lethal inoculac of CT26 cells, and iii) by evaluating combination drug and vaccine treatment efficacy against established CT26 tumors. Using this approach, doxorubicin was found to possess apparent immunostimulatory activities, depending on the dose and schedule of administration, while cyclophosphamide appeared immunosuppressive. The different immunomodulatory properties of doxorubicin and cyclophosphamide may be clinically relevant: combination doxorubicin and vaccine treatment of established CT26 cancers increased cure rates over that achieved with either agent alone, while combination cyclophosphamide and vaccine treatment of animals carrying CT26 tumors was no better in curing the animals than drug treatment alone.
Induction of antitumor effect on human esophageal carcinoma cells by the retroviral expression of granulocyte macrophage-colony stimulating factor gene.
Sugaya M. Tagawa M. Matsubara H. Gunji Y. Takenaga K. Maeda T. Koide Y. Asano T. Ochiai T. Isono K. Sakiyama S.
Department of Surgery (II), School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260, Japan.
We have examined antitumor effect of human esophageal carcinoma cells (T.Tn) which were retrovirally transduced to express mouse granulocyte macrophage-colony stimulating factor (mGM-CSF) gene. Nude mice inoculated with T.Tn cells secreting mGM-CSF developed small tumors but the tumors regressed spontaneously, although the proliferation in vitro of transduced cells was not different from that of wild-type cells. In contrast, the tumor of T.Tn cells transduced with human GM-CSF grew as that of wild-type cells, since murine GM-CSF receptors do not bind to human GM-CSF. Histological examination of the regressing tumor of mGM-CSF-producing T.Tn cells revealed predominant infiltration of inflammatory cells including macrophages. In addition, local injection of mGM-CSF-producing T.Tn cells into the established wild-type tumors significantly induced the retardation of subsequent wild-type tumor growth, suggesting that T-cell independent local response plays a crucial role in destroying tumor cells.
DNA synthesis, mismatch repair and cancer.
Hoffmann JS. Cazaux C.
Institut de Pharmacologie et de Biologie Structurale, CNRS UPR 9062, 205 route de Narbonne, 31077 Toulouse cedex, France.
The entire nucleotide sequence of the genome must be transmitted from one generation to the next with no or few errors. Preservation of this integrity requires multiple genes whose alteration can lead to an early event in tumorigenesis by increasing the mutation rate. This mutator phenotype would provide a continuing pool of mutants upon which selection could act to promote a tumor. Recent evidence consistant with this hypothesis is the mutator phenotype of tumor cells of patients with a hereditary form of colon cancer (HNPCC) which exhibit a several hundred-fold increase in spontaneous mutations in addition to a high degree of microsatellite instability. The multiple genomic alterations increasingly reported as associated with most cancers may therefore be linked to a variety of DNA metabolic processes guardians of the genome, including fidelity of the DNA synthesis and mismatch repair. The connection between cancer and deregulation of nucleotide synthesis, imbalance of the pools of nucleotides, deficiency of DNA polymerases, and mismatch repair is the subject of this review. We consider how perturbation in these DNA transactions results in instability of the genome and cancer.
Characterization of CCK-B/gastrin-like receptors in human gastric carcinoma.
Smith JP. Shih AH. Wotring MG. McLaughlin PJ. Zagon IS.
Division of Gastroenterology, The Milton S. Hershey Medical Center, The Pennsylvania State University, 500 University Drive, Hershey, PA, 17033-0850, USA.
In this study we identified and characterized the receptor related to the modulation of growth of human gastric cancer by gastrin. By performing receptor binding assays on human AGS gastric cancer cells with the selective CCK-B/gastrin receptor antagonist [3H]L-365,260, specific and saturable binding were determined. Binding was dependent on protein concentration, time, temperature, and the presence of protease inhibitors, and was located in the membrane fraction. Gastrin, as well as CCK, stimulated gastric cancer cell growth in a receptor-mediated fashion at a concentration consistent with the binding affinity. Receptor gene expression for the CCK-B/gastrin receptor, but not for the CCK-A receptor, was found by reverse transcription polymerase chain reaction. Receptor binding assays as well as transcriptional and growth studies provide evidence that gastrin-stimulated growth of human gastric cancer is mediated by CCK-B/gastrin-like receptors.
Clinicopathologic study of multiple primary superficial carcinoma of the esophagus.
Fujii T. Yamana H. Fujita H. Sueyoshi S. Nakashima A. Hayashi I. Nishi M. Kato S. Shirouzu K. Morimatsu M.
Department of Surgery and Second Department of Pathology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Japan.
Endoscopic examination with iodine staining has led to the easy detection of multiple superficial esophageal carcinoma (MSEC). The purpose of this study was to better understand the characteristics of MSEC. Of 49 patients with multiple esophageal carcinomas, 19 had superficial carcinoma. Multiple esophageal carcinomas were more often found in superficial carcinomas (31.1%) than in advanced carcinomas (14.4%). Comparing the depth of invasion of multiple esophageal carcinomas, the secondary lesions represented relatively early stages. Ki-67-positive cells were seen significantly more frequently in the main lesion of MSEC than in the secondary lesions, but proliferating cell nuclear antigen positivity and p53 expression did not differ significantly. Since multiple carcinoma occurs more frequently, care should be taken to look for small secondary lesions when treating superficial esophageal carcinoma. Ki-67 immunohistochemistry suggested that tumor cells proliferate more slowly in secondary lesions than in main lesions of MSEC.
Immunoexpression of E-cadherin and beta-catenin correlates to survival of patients with hepatocellular carcinomas.
Garcia S. Martini F. De Micco C. Andrac L. Hardwigsen J. Sappa P. Lavaut MN. Le Treut YP. Charpin C.
Service d'Anatomie et Cytologie Pathologiques, Faculte de Medecine, Secteur Nord. Bd P. Dramard, Marseille, cedex 20, 13915, France.
Expression of E-cadherin (E-cad) and -catenin ( -cat) was investigated immunohistologically in 91 cases of excised hepatocellular carcinomas. Immunodectection was altered in 56% of tumours for E-cad and in 30.8% for -cat. Downregulation of E-cad and -cat correlated with the size of tumours, and high nuclear grade, but only E-cad alteration correlated with the mitotic index. Alterations of E-cad and -cat expression correlated with survival. Although E-cad and -cat immunodetections were independent prognostic factors, their prognostic value was lower than that of current clinicopathological parameters.
p53 overexpression in small hepatocellular carcinomas containing two different histologic grades.
Nakashima Y. Hsia CC. Yuwen H. Minemura M. Nakashima O. Kojiro M. Tabor E.
Division of Transfusion Transmitted Diseases, Food and Drug Administration, Bethesda, MD, USA.
There is evidence to suggest that a focus of less-differentiated hepatocellular carcinoma (HCC) may arise within a pre-existing well-differentiated HCC, eventually replacing it. In the present study, the p53 tumor suppressor gene was analyzed by immunohistochemistry in 31 hepato-cellular carcinomas (HCCs) containing two or more regions in the same nodule with different histologic grades. p53 was overexpressed in the nucleus in 13 of 31 HCCs (42%), in seven of which p53 overexpression was seen only in the less-differentiated area of the tumor. This suggests that overexpression of presumed mutant p53 may have contributed to dedifferentiation during the development of HCC.
Polymorphonuclear elastase in human colorectal carcinoma.
Bjornland K. Buo L. Scott H. Konttinen Y. Johansen HT. Aasen AO.
Institute for Surgical Research, The National Hospital, 0027 Oslo, Norway.
proteinases are required for invasion through the extracellular matrix (ECM) during tumor invasion and metastasis. Polymorphonuclear (PMN) elastase can degrade ECM components and modulate other proteinases. In the present study PMN elastase activity was found in tissue extracts from 8 of 15 human colorectal carcinomas. Immunoreactive PMN elastase was demonstrated in all carcinoma biopsies with particular enrichment at the tumor-host interface. Immunofluorescence staining localized immunoreactive PMN elastase mainly to neutrophile granulocytes. The human colon carcinoma cell lines Caco-2 and HT-29 did not express PMN elastase. An interaction between tumor cells and elastase producing leukocytes is suggested.
Establishment of a new human myeloma cell line, KMS-18, having t(4;14)(p16.3;q32.3) derived from a case phenotypically transformed from Ig A-lambda to BJP-lambda, and associated with hyperammonemia.
Otsuki T. Nakazawa N. Taniwaki M. Yamada O. Sakaguchi H. Wada H. Yawata Y. Ueki A.
Department of Hygiene, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-01, Japan.
A new human myeloma cell line, KMS-18, was established from a 58-year-old male with multiple myeloma associated with hyperammonemia. The original leukemic cells and established KMS-18 cells possessed several of the same chromosomal abnormalities, including add(1)(q32), add(10) (q24) and add(17)(p11). In addition, the KMS-18 cells showed novel t(4;14)(p16.3;q32.3) masked translocation which was determined by the FISH method. Moreover, we compared the ammonia production in culture medium of the KMS-18 cell line with that of non-myeloma hematological malignant cell lines and a hepatocellular carcinoma cell line. KMS-18 produced higher levels of ammonia in medium than the other cell lines examined. This new cell line may prove helpful in analyzing the role and biological mechanisms of the t(4;14)(p16.3;q32.3) translocation in myeloma and also in investigating hyperammonemia in cases with myeloma.
The role of proteolytic enzymes in the pathology of epithelial ovarian carcinoma.
Stack MS. Ellerbroek SM. Fishman DA.
Northwestern University Medical School, 303 E. Chicago Ave, Tarry 4-751, Chicago, IL 60611, USA.
Epithelial ovarian cancer is the leading cause of death from gynecologic malignancy among North American women. The vast majority of women are diagnosed after the cancer has metastasized into the peritoneum, resulting in a low 5-year survival. Because of difficulties associated with early detection of ovarian carcinoma and the invasive potential of these malignancies, a more detailed understanding of the mechanism(s) by which ovarian carcinomas metastasize may suggest novel therapeutic approaches which could impact favorably on long-term survival. Connective tissue degrading proteinases are necessary for tumor cell invasion and enzymes in the plasminogen activator (PA) and matrix metalloproteinase (MMP) families have been implicated in ovarian cancer metastasis. The goal of this review is to summarize current data regarding the role of these proteinases in ovarian carcinoma invasion.
Mutational study of p16CDKN2/MTS1/INK4A and p57KIP2 genes in hepatocellular carcinoma.
Bonilla F. Orlow I. Cordon-Cardo C.
Molecular Genetics Unit, Clinica del Trabajo, Avd. de la Reina Victoria, 21, Madrid, 28003, Spain.
p16 and p15 are representative members of cyclin-dependent kinase inhibitors. Because the selective expression of p57KIP2 in liver, and because p16CDKN2/MTS1/INK4A has been found altered in many primary tumors, we undertook the present study to determine the presence of alterations in these genes in a group of hepatocellular carcinomas (HCC). Seventeen tumor and normal DNA pairs were analyzed by Southern blot, PCR-SSCP and DNA sequencing. Microsatellite markers surrounding the area of the p16 gene was also used. Southern blot analysis did not show allelic losses of the p16 or p57KIP2 genes. In 4 cases, an extra band was observed when hybridizing with the specific p16 cDNA. Overall, 4/17 (24%) cases presented microsatellite alterations at the 9p21-24 region. These results suggest that deletions or point mutations in these genes are not frequent if present at all in HCC, but reveals the existence of microsatellite alterations at the 9p21-24 region in HCC.
The selective reduction in PTPdelta expression in hepatomas.
Urushibara N. Karasaki H. Nakamura K. Mizuno Y. Ogawa K. Kikuchi K.
Section of Biochemistry, Institute of Immunological Science, Hokkaido University, Kita-15, Nishi-7, Kita-Ku, Sapporo 060, Japan.
The mRNA levels for receptor-like protein tyrosine phosphatases (PTPases), PTPalpha, PTPdelta, PTPgamma and LAR, were evaluated by Northern blot analysis in two types of chemically-induced rat primary hepatomas. In the four PTPases the PTPdelta mRNA was selectively reduced in these hepatoma tissues. It was also diminished in HepG2 hepatoblastoma cell line and in all of the poorly differentiated ascites hepatoma cells examined. PTPalpha, PTPgamma and LAR did not show such a characteristic decrease. This selective reduction in PTPdelta expression strongly suggests PTPdelta plays an important role in hepatocarcinogenesis, possibly as a tumor suppressor gene.
Growth suppression mediated by transfection of wild-type hMLH1 in human cancer cells expressing endogenous truncated hMLH1 protein.
Shin KH. Han HJ. Park JG.
Laboratory of Cell Biology, Cancer Research Center and Cancer Research Institute, Seoul National University, College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-799, Korea.
Many genes that are frequently mutated in human cancer are known to be involved in the control of normal cellular proliferation. One of the genes involved in DNA mismatch repair is hMLH1, defective mutations of which are found in some familial and various sporadic cancers. Although the DNA mismatch repair activity of hMLH1 has been identified, other biological functions of hMLH1 have not been well investigated. To investigate the effect of wild-type hMLH1 in cellular proliferation, wild-type hMLH1 cDNA was introduced into human colorectal carcinoma cell line HCT116 and human gastric carcinoma cell line SNU-1, each containing a homozygous non-sense mutation at codon 252 and 226 in hMLH1, repectively. The hMLH1-transfected stable clones showed mRNA and protein expression of transfected hMLH1. Three in vitro cell growth experiments demonstrated that compared with parental and vector-transfected control counterparts, both hMLH1-transfected HCT116 and SNU-1 clones displayed: i) decreased cellular proliferation; ii) a significant decrease in the rate of DNA synthesis and iii) a dramatic reduction of anchorage-independence and the size of colonies in semisolid medium. In addition to DNA repair activity, these results suggest that hMLH1 may play a role in the negative regulation of HCT116 and SNU-1 cell growth.
Hepatocyte growth factor enhances the invasion activity of human hepatocellular carcinoma cell lines.
Kamiyama T. Une Y. Uchino J. Hamada J.
Kushiro Rosai Hospital, 13-23 Nakazono-cho, Kushiro, 085, Japan.
We investigated whether hepatocyte growth factor (HGF) enhances the invasion activity of three human HCC cell lines, HLF, HLE, and HC-4, in vitro. The analysis of the invasiveness consisted of the production of u-PA and the chemotaxis for fibronectin. Invasion activity of all cell lines was enhanced by the addition of recombinant human hepatocyte growth factor (rhHGF) to the medium. HGF stimulated the production of u-PA in HLF cells. HGF accelerated the chemotaxis of HC-4 and HLE. These data suggest that HGF increase the invasion activity of human HCC cell lines by affecting the production of u-PA or the chemotaxis for fibronectin.
Glyceraldehyde-3-phosphate dehydrogenase mRNA expression in hepatocellular carcinoma.
Yamagata M. Mori M. Begum NA. Shibuta K. Shimoda K. Barnard GF.
Medical Institute of Bioregulation, Department of Surgery, Kyushu University, Beppu, Japan.
Glyceraldehyde-3-phosphate dehydrogenase (G3PDH) is often used as a control gene for mRNA expression, however it has been proposed to be overexpressed in all hepatocellular carcinomas (HCC). Equal amounts of tumor and paired normal (T/N) RNA, based on OD260/280 nm, were compared using ethidium bromide staining, poly-T probing, gene-specific dot blot and Northern blots using control probes G3PDH, actin and histone H4. Using mRNA blots 13/20 surgical HCC pairs did not overexpress G3PDH. Those 7/20 intact samples which did appear to overexpress G3PDH on Northern blot could not be detected by poly-T probing of dot blots. The apparent overexpression was not specific for the control gene G3PDH nor for the malignancy HCC. It may represent partial mRNA degradation, or the presence of as yet unknown substances which interfere with absorption at 260/280 nm. We advise caution in selecting human T/N pairs for differential gene expression studies. For HCC, no clinicopathological variables, including cirrhosis, predicted whether a T/N sample pair was likely to be balanced or not.
Lovastatin inhibits proliferation of pancreatic cancer cell lines with mutant as well as with wild-type K-ras oncogene but has different effects on protein phosphorylation and induction of apoptosis.
Muller C. Bockhorn AG. Klusmeier S. Kiehl M. Roeder C. Kalthoff H. Koch OM.
Department of Internal Medicine A, University of Munster, Germany.
Besides its pharmacological effect on cholesterol biosynthesis, lovastatin inhibits p21ras proteins by substrate depletion for post-translational protein farnesylation and geranylation. This inhibition has previously been used to reverse cell proliferation after cellular transformation by the mutant p21ras oncogene. We investigated the biological effects of lovastatin on two pancreatic carcinoma cell lines. The SW-850 cell line contained the k-ras wild-type gene and the A818-4 cell line contained the mutant gene with a point mutation at codon 12 (GGTZCGT; glyZarg). Lovastatin inhibited the proliferation of pancreatic carcinoma cells dose-dependently showing an IC20-30 at 5 microM and IC40-50 at 10 microM. Proliferation of both cancer cell lines, A818-4 (p21ras-M) and SW-850 (p21ras-WT) were inhibited to a very similar extent. After 24 h of drug exposure, cell cycle arrest in G1 and G2/M-phase occurred in a large proportion of cells. At this time, neither cell line showed alteration of protein phosphorylation and did not undergo apoptosis. However, after 72 h of drug exposure, lovastatin significantly decreased protein phosphorylation on tyrosine, serine and threonine residues in A818-4 (p21ras-M) cells. Only a minute reduction of protein phosphorylation was detected in SW-850 (p21ras-WT) cells. Apoptosis occurred in both cell lines, but the SW-850 (p21ras-WT) showed a higher percentage of apoptotic cells than the A818-4 (p21ras-M). In conclusion, there is further evidence for a growth inhibitory effect on cancer cells regardless of the ras mutation status. However, as the effects on protein phosphorylation and induction of apoptosis differed between the mutant and wild-type cell lines, the mechanism of action of lovastatin may depend on partially different mechanisms.
Diagnosis of the level of depth in superficial depressed-type colorectal tumors in terms of stereomicroscopic pit patterns.
Kawano H. Tsuruta O. Ikeda H. Toyonaga A. Tanikawa K.
Second Department of Medicine, Kurume University, School of Medicine, 67 Asahi-machi, Kurume City 830, Japan.
We investigated the relationship between stereomicroscopic pit patterns and histological structures in 93 lesions of superficial depressed-type colorectal tumors to assess the possibility of diagnosing the level of invasion by the pit patterns. All 9 lesions with Va (amorphous)-type pit pattern showed massive invasion into the submucosal layer (sm2, sm3). Massive invasion into sm was observed in 66.7% (6/9) of lesions with Vi (irregular)-type pit pattern, whereas 22.2% (2/9) of the lesions invaded the shallow layer of the submucosa (sm1) and 11.1% (1/9) were limited to the mucosa. Among the lesions with pit patterns other than Va and Vi, 93. 3% (70/75) were limited to the mucosa, whereas 6.7% (5/70) invaded the submucosal layer, but all were limited to sm1. These findings show that stereomicroscopic analysis of the pit patterns of the superficial depressed-type colorectal tumors is useful for diagnosing the level of invasion.
Heterogeneous induction of apoptosis in colon cancer cells by wild-type p53 gene transfection.
Namoto M. Yonemitsu Y. Nakagawa K. Hashimoto S. Kaneda Y. Nawata H. Sueishi K.
First Department of Pathology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan.
To examine the effects of wild-type (wt)-p53 gene transfer on cancer cell growth and apoptosis induction, we transduced human wt-p53 cDNA into three colon cancer cell lines either with or without a mutation of the p53 gene using the HVJ-cationic liposome method. Wt-p53 gene transfer, thus, induced an apparent growth arrest in all cell lines, but its enhancement of the apoptotic rate varied (from about 4 to 70 times). The simultaneous doxorubicin treatment was able to enhance growth arrest and the apoptosis induction rate. These findings suggest that wt-p53 gene transfer using HVJ-cationic liposomes seems to be a potentially effective therapeutic strategy, however wt-p53 gene transfer still appears to be more effective in combination with other cytotoxic treatments.
p53 genetic alterations, protein expression and autoantibodies in human colorectal carcinoma: A comparative study.
Hallak R. Mueller J. Lotter O. Gansauge S. Gansauge F. el-Deen Jumma M. Montenarh M. Safi F. Beger H.
Department of Clinical Biochemistry, University of Damascus Syria.
This study investigated a total number of 120 colorectal malignant tumor tissues by applying a new quantitative luminometric assay (LIA)-mat, immunohistochemistry (IHC) (n=100), PCR/SSCP (n=42), and sequencing (n=7). Sera were collected from 235 patients suffering from colorectal carcinoma in addition to 195 healthy individuals as a control group. Manual ELISA kit was developed to detect p53 autoantibodies in the sera of those patients. Our data demonstrated that the LIA-mat yields reliable estimates of p53 expression in soluble cell extracts as compared with results obtained by immunohistochemistry which showed positive immunostaining in 63% of the studied cases. Using a cut-off value of 1.8 ng/mg protein, 65 tumors out of 120 (54%) were classified to be positive by LIA-mat, manifesting protein overexpression, while 22 out of 42 (52%) tumor samples showed p53 gene alteration when applying single strand conformation polymorphism (SSCP) analysis on polymerase chain reaction products. In tumor samples without a p53 gene alteration, the median soluble p53 protein level was 4.3 ng/mg protein, whereas the median p53 protein level for tumor samples with p53 gene alteration was 7.5 times higher. Despite a significant correlation between the outcome of LIA and SSCP, a disagreement was found in 30% of cases. We found no significant correlation between p53 protein overexpression and clinicopathological findings except for distant metastasis (p=0.33), indicating p53 immunoreactivity to be an independent prognostic factor. Our data showed that 18% of patients suffering from colorectal cancer developed autoantibodies against p53 in their sera which might be an early indicator for tumor development and distant metastasis.
TGF-beta1 produced by gastric cancer cells affects mesothelial cell morphology in peritoneal dissemination.
Nishimura S. Hirakawa-Chung KY. Yashiro M. Inoue T. Matsuoka T. Fujihara T. Murahashi K. Sawada T. Nakata B. Jikihara I. Takagi H. Sowa M.
First Department of Surgery, Osaka City University Medical School, 1-5-7 Asahimachi, Abeno-ku, Osaka 545, Japan.
In vitro morphologic change of mesothelial cells was observed following the addition of serum-free conditioned medium (SF-CM) from peritoneal dissemination cell line OCUM-2MD3. The same morphologic change of mesothelial cells was observed following the addition of 10 ng/ml TGF-beta1, but not following the addition of b-FGF, IGF-I, VEGF or PDGF-AA. In the in vivo study, mesothelial cells of mice treated with SF-CM from OCUM-2MD3 and TGF- beta1 were separated from one another, resulting in exposure of the submesothelial connective tissue. The molecular size of the mesothelial morphology changing activity was estimated by running the SF-CM from OCUM-2MD3 through a gel filtration column TSK-gel G2000SW. The mesothelial morphology changing activity was recognized at positions equivalent of Mr 6, 500-30,000. 25 kDa TGF-beta1 was detected in the active fraction from the TSK-gel G2000SW column and the SF-CM of OCUM-2MD3 by Western blotting using a monoclonal antibody against TGF-beta1. These findings suggest that TGF-beta1 produced by gastric cancer cells changes the morphology of mesothelial cells and may thus be closely associated with peritoneal dissemination.
Cell kinetic patterns in early gastric cancer.
Spina D. Miracco C. Vindigni C. Gallorini M. Presenti L. Marrelli D. Roviello F. Pinto E. Filipe MI. Tosi P.
Institute of Pathological Anatomy and Histology, University of Siena, Italy.
Early gastric cancers (EGC) may be subdivided into 2 groups by means of the use of mitotic index, apoptotic index and cell density: EGCs with high cell turnover and low cell density, which show high cell dissociation and, more frequently, lymph node invasion; EGCs with low cell turnover and high cell density. The same parameters discriminate among intestinal type tumors, when separately considered from diffuse ones. No correlation is noted of these 2 groups with transforming growth factor-alpha, epidermal growth factor receptor and p53 expression, gross type, entity of neoangiogenesis, and submucosal invasion.
Genetic identification and management of hereditary nonpolyposis colorectal cancer.
Park JG. Yuan Y.
Laboratory of Cell Biology, Cancer Research Institute, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul, 110-744, Korea.
Hereditary nonpolyposis colorectal cancer (HNPCC) is a syndrome involving a predisposition to cancers of the colon, endometrium and several other extra-colonic sites, accounting for approximately 1-5% of all colorectal cancer cases. It is not easily recognized because of a lack of distinctive clinical markers, making diagnosis and management of this disease problematic. To provide a basis for uniformity in diagnosis of HNPCC, the Amsterdam criteria were proposed and are currently in use. More recently, the discovery of four human mismatch repair genes (hMSH2, hMLH1, hPMS1 and hPMS2) has provided novel insight into the genetic basis of this disease, and raised the possibility of genetic diagnosis for management of HNPCC patients and their family members. This report summarizes the clinicopathologic aspects of HNPCC, reviews the recent genetic findings and surveillance strategies, and suggests a novel designation of certain patients as suspected HNPCC.
Characterization, cloning and expression of the Tage4 gene, a member of the immunoglobulin superfamily.
Laboratoire de Biochimie Specialisee, Institut de Biologie, 9 quai Moncousu, Nantes, 44035, France.
pE4 is a rat carcinoma-associated antigen identified by monoclonal antibody E4, which was raised against a rat colon carcinoma cell line. This glycoprotein is expressed at the surface of all the rat colon carcinoma cell lines tested, as determined by immunofluorescence analysis. In contrast, a barely detectable level was found on normal adult rat colon and lung and no expression could be detected on the other normal rat tissues tested. The corresponding Tage4 gene (tumor-associated glycoprotein E4) is also expressed in rat colon tumors induced by 1,2-dimethylhydrazine and in Min mouse intestinal adenomas. The Tage4 gene product is closely related to the hepatocellular carcinoma antigen TuAg.1. The Tage4 cDNA has been isolated and sequenced. Analysis of the deduced aminoacid sequence indicated that Tage4 is a member of the immunoglobulin supergene family. This family contains cell adhesion molecules which have wide-ranging functions and mediate a variety of homotypic and heterotypic cellular interactions playing a general role in cell surface recognition. The Tage4 gene has been mapped to rat chromosome 1q22 and mouse 7A2-B1, regions that are homologous to the long arm of human chromosome 19. Summary review of our work is presented.
Expression of vascular endothelial growth factor correlates with tumor progression in gallbladder cancer.
Okita S. Kondoh S. Shiraishi K. Kaino S. Hatano S. Okita K.
First Department of Internal Medicine, Yamaguchi University, 1144 Kogushi, Ube, Yamaguchi, 755, Japan.
Angiogenesis must occur for malignant tumors to proliferate and vascular endothelial growth factor (VEGF) is now believed to be central to this process. Immunohistochemical staining for VEGF was performed on surgical resection specimens from 50 patients with gallbladder cancer. VEGF-positive rate was 38%. Comparison of clinicopathologic parameters between the groups with and without VEGF expression showed significant differences in tumor size, lymphatic invasion and disease stage. Survival rate was worse in the patients whose tumors demonstrated VEGF expression. It is suggested that VEGF is correlated with tumor progression and may be used as a prognostic indicator.
Usefulness of K-ras gene mutation at codon 12 in bile for diagnosing biliary strictures.
Ito R. Tamura K. Ashida H. Nishiwaki M. Nishioka A. Yamamoto Y. Furuyama JI. Utsunomiya J.
Second Department of Surgery, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo, 663, Japan.
Point mutations of the K-ras gene at codon 12 are often detected in the pancreatic juice of patients with pancreatic cancer. Detection of these mutations may, thus, have diagnostic implications. K-ras mutations may also have diagnostic potential for other biliary tumors. We sought to detect K-ras mutations in DNA obtained from bile in patients with biliary tract cancers, pancreatic cancer and benign biliary disease but who had obstructive jaundice. In 35 patients, bile was collected during percutaneous transhepatic choledocal drainage (PTCD) catheters. K-ras gene mutations at codon 12 in the samples were examined using mutant-allele-specific-amplification (MASA). We compared these results with cytological analyses of bile. K-ras mutations at codon 12 in bile were detected in 11 of 14 (79%) of the patients with biliary duct cancer, 3 of 9 (33%) with pancreatic cancer but not in patients with gallbladder cancer (n=3), papilla of Vater's cancer (n=3) or benign biliary diseases (n=6). In the patients, where cytological evaluation did not reveal malignant cells, K-ras mutations in bile were detected in 5 of 7 (71%) patients with biliary duct cancer and 2 of 5 (40%) with pancreatic cancer. This approach, when used in conjunction with bile cytology, may improve the yield in diagnosing suspected malignant tumors of the pancreatic-biliary system.
Hereditary and sporadic ovarian cancer: genetic testing and clinical implications (review).
Angioli R. Estape R. Mason M. Penalver M.
Division of Gynecologic Oncology (D-52), Jackson Memorial Hospital, University of Miami School of Medicine, 1611 N.W. 12th Ave., ET 7007, Miami, FL 33136, USA.
The two most common forms of hereditary ovarian cancer are: the breast ovarian cancer syndrome, and ovarian cancer associated with HNPCC (hereditary nonpolyposis colorectal cancer) syndrome. Studies have shown that these diseases may be associated with mutations in a number of tumor suppressor genes, mainly BRCA1 and BRCA2. Malfunction of the protein products of these genes have also been found to be involved in sporadic ovarian cancer, which makes up the majority of ovarian cancer cases. HNPCC-ovarian cancer associated families reveal frequent mutations in at least four genes (hMSH2, hMLH1, hPMS1, and hPMS2) involved in the repair of mismatched DNA. With ovarian cancer being such an important health issue, the push is on to design reliable screening tests to detect defective inherited or somatic alleles in individual carriers. So far, most progress has been demonstrated in those patients with family histories of the disease who are at increased risk. The ramifications of such research may impact a variety of scientific, clinical, legal, ethical, and psychosocial issues. In addition to current treatment modalities, positive results of these tests may indicate the need for increased clinical surveillance, prophylactic treatment, and genetic counseling of patients on an individual basis. It remains to be seen whether the technology can be made reliable enough to not only benefit high-risk individuals but also the general population.
Mutation of the transforming growth factor-beta type II receptor gene is a rare event in human sporadic gastric carcinomas.
Shitara Y. Yokozaki H. Yasui W. Takenoshita S. Nagamachi Y. Tahara E.
First Department of Pathology, Hiroshima University School of Medicine, Hiroshima 734-8551, Japan.
Mutations of the transforming growth factor-beta type II receptor (TGF-beta RII) gene have been detected in several human cancers. However, mutation analysis of coding sequences of TGF-beta RII in gastric carcinomas has not yet been fully elucidated. We performed PCR-SSCP analysis and direct DNA sequencing of the entire coding region of TGF- RII in 38 human sporadic gastric cancers and 8 gastric cancer cell lines. Mutations of the TGF-beta RII were detected in two tumors and three cell lines. Two tumors had one base deletion in the polyadenine tract in exon 3, the cystein-rich extracellular domain. Three cell lines had a silent mutation in the kinase domain located in exon 4. Polymorphisms were detected in introns 2 and 3. An a/g polymorphism was observed at the seventh base in intron 2 and an a/t polymorphism was observed at the fourth to last base in intron 3. There were no mutations in exons 1, 2, 5, 6 and 7. These results indicate that the polyadenine tract in the TGF-beta RII is a mutational hot spot in human gastric cancer. However, these results also suggest that mutations of the gene are rare events in human sporadic gastric cancer.
Aberrant p16INK4 expression related to clinical stage and prognosis in patients with pancreatic cancer.
Naka T. Kobayashi M. Ashida K. Toyota N. Kaneko T. Kaibara N.
First Department of Surgery, Faculty of Medicine, Tottori University, 36-1 Nishicho Yonago, Tottori, 683-8504, Japan.
The p16 tumor suppressor gene is thought to play an important role in cell cycle regulation by encoding for protein products that can inhibit the progression from G1 to S phase in the cell cycle. Recently, the p16 gene has been found to be mutated or deleted in a variety of different types of primary human malignant tumors and human-derived malignant tumor cell lines. In this study, primary ductal pancreatic adenocarcinomas from 32 human patients were analyzed immunohistochemically for expression of p16 protein, with emphasis on the role of abberant p16 protein expression as a prognostic indicator. In addition, the same tumors were also assessed for p53 protein expression, AgNOR counts, and DNA ploidy. Nineteen out of the 32 cases (59%) showed positive immunoreactivity for p16 protein in their tumors and a significant association was found between lack of p16 protein expression, and both advancing clinical stage classification of disease, and poorer survival (p
P-glycoprotein-mediated multidrug resistance is modulated by pretreatment with chemosensitizers in HCT-8 carcinoma cells in vitro.
Haberl I. Swatonek H. Schaufler K. Ulsperger E. Wenzl E. Theyer G. Hamilton G. Thalhammer T.
Department of Surgery, University of Vienna, Vienna, Austria.
The effects of pretreatment with the multidrug resistance (MDR) modulators verapamil (VPM), tamoxifen (TMX), cyclosporin A (CsA), and SDZ PSC833 (PSC) on drug sensitivity of the P-glycoprotein (Pgp) expressing human ileocecal carcinoma cell line HCT-8 is described. Following pretreatment of 2, 16 and 48 h with the individual modulators, rhodamine 123 efflux (RHO), transepithelial vinblastine transport (VIN) across treated HCT-8 monolayers, and chemosensitivity to doxorubicin (DOX) were determined and compared to Pgp protein expression and phosphorylation. After 2 h, VPM, TMX, CsA and PSC inhibited RHO efflux and VIN transport and increased the chemosensitivity of HCT-8 to DOX significantly. Prolonged exposure failed to further increase inhibition of Pgp-mediated transport, but in contrast maximized phosphorylation of Pgp (16 h) and Pgp protein expression (48 h), respectively.
Angiogenesis in hepatocellular carcinoma: an experimental study in the chick embryo chorioallantoic membrane.
Marzullo A. Vacca A. Roncali L. Pollice L. Ribatti D.
Institute of Pathology, University of Bari Medical School, I-70124 Bari, Italy.
Ten samples of human hepatocellular carcinoma and three of a laceration injure of the liver (controls) were grafted onto the chick embryo chorioallantoic membrane (CAM) to investigate their possible angiogenic activity. The angiogenic response in pathological and control implants was assessed on histologic sections by a morphometric method, 4 days after grafting. The vascular count in the CAMs treated with the pathological implants was significantly higher compared to control ones and the angiogenic response induced by pathological implants was comparable to that of a well known angiogenic molecule, namely basic fibroblast growth factor. The role played in vasoproliferative response by angio-genic cytokines released by tumor cells, by CAM extracellular matrix and by the perivascular mononuclear cells was supported by this study.
A novel dosage approach for evaluation of SMANCS [poly-(styrene-co-maleyl-half-n-butylate) - neocarzinostatin] in the treatment of primary hepatocellular carcinoma.
Seymour LW. Olliff SP. Poole CJ. De Takats PG. Orme R. Ferry DR. Maeda H. Konno T. Kerr DJ.
CRC Institute for Cancer Studies, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
We report a Phase I/II clinical trial of poly-(styrene-co-maleyl-half-n-butylate)-neocarzinostatin (SMANCS) for intra-arterial treatment of hepatoma. Early patients received 4 or 8 mg SMANCS dissolved in Lipiodol; later patients were treated according to tumour size and degree of filling achieved. SMANCS/Lipiodol drained rapidly from normal liver but was retained within tumour interstitium. Tumour nodules filled with SMANCS/Lipiodol usually stabilised and often regressed. No UICC criteria-defined responses were achieved, partly due to difficulties of filling several lesions simultaneously. Signs of therapeutic activity suggest a more extensive clinical study is warranted.
Frequent microsatellite instability and loss of heterozygosity in the region including BRCA1 (17q21) in young patients with gastric cancer.
Semba S. Yokozaki H. Yasui W. Tahara E.
First Department of Pathology, Hiroshima University School of Medicine, Hiroshima 734-8551, Japan.
It is known that nearly 5% of gastric carcinomas arise under the age of 40. To elucidate genetic alterations in these patients, we performed studies using microsatellite assay in 27 gastric cancers under 35 years of age, composed of 5 well and 22 poorly differentiated adenocarcinomas. We detected replication errors (RERs) in 18 (67%) of 27 tumors, but no germline mutation in DNA mismatch repair genes (hMLH1 and hMSH2), except fory 3 somatic mutations in the hMLH1 gene. Loss of heterozygosity (LOH) at D17S855, located on chromosome 17q21 (BRCA1), was detected in 8 (40%) of 20 informative cases. In 12 (44%) of 27 cases, LOH on chromosome 17q12-21 including the BRCA1 was found in several neighboring markers in this region, while no mutation was found in the BRCA1 gene. Four (40%) of 10 scirrhous type gastric cancers exhibited wide allelic deletions on chromosome 17q12-21. These results overall suggest that young gastric cancer patients display highly frequent micro-satellite instability that might be due to defect of DNA repair system rather than hMLH1 and hMSH2. In addition, chromosome 17q12-21 including BRCA1 locus may contain a candidate for tumor suppressor gene, particularly in scirrhous type gastric cancers arising in young patients.
Expression of CD44 containing variant exon 9 (CD44v9) in gastric adenomas and adenocarcinomas: relation to the proliferation and progression.
Yasui W. Kudo Y. Naka K. Fujimoto J. Ue T. Yokozaki H. Tahara E.
First Department of Pathology, Hiroshima University School of Medicine, Hiroshima 734-8551, Japan.
The expression of CD44 splice variant containing exon 14 (variant exon 9: CD44v9) was examined immunohistochemically in non-neoplastic mucosa, adenoma and adenocarcinoma of the stomach and analyzed the relation with the expression of Ki-67 antigen and p53 protein. In non-neoplastic gastric mucosa, basolateral membrane of the epithelial cells in the pyloric glands showed the expression of CD44v9. The epithelial cells in the intestinal metaplastic mucosa of the stomach sometimes expressed CD44v9. In the neoplastic lesions, the expression of CD44v9 was detected in 20% (34/170) of the adenomas and 28% (132/478) of the adenocarcinomas, respectively. The incidence of CD44v9 expression did not differ among histological type of gastric carcinoma. Twelve per cent of the adenocarcinomas showed strong expression of CD44v9, whereas non of the adenomas did. The incidence of CD44v9 expression was significantly higher in carcinomas invading into muscularis propria or the cases of stages 3 and 4 in comparison with that in carcinomas limited to submucosa or the stages 1 and 2 cases (p
3F8 monoclonal antibody treatment of patients with stage 4 neuroblastoma: a phase II study.
Cheung NK. Kushner BH. Yeh SD. Larson SM.
Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
3F8 is an IgG3 murine monoclonal antibody directed against the ganglioside GD2. In a phase II study, 3F8 was administered i.v. to 16 patients (pts) who had stage 4 neuroblastoma. Response was seen in bony lesions (2 of 7 pts) and marrow (3 of 8 pts). Acute toxicities of pain, fever, urticaria, hypertension, hypotension and anaphylactoid reactions were self-limited and manageable. Three pts are long-term survivors between 79-130+ months after 3F8 treatment without additional systemic therapy and no delayed neurological complications. The potential benefits of 3F8 when added to chemoradio-therapy warrant further investigation.
Reduced expression of mismatch repair genes in colorectal cancer patients in Egypt.
Soliman AS. Bondy ML. Guan Y. El-Badawi S. Mokhtar N. Bayomi S. Raouf AA. Ismail S. McPherson RS. Abdel-Hakim TF. Beasley RP. Levin B. Wei Q.
Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
An Egyptian hospital-based pilot case-control study was conducted to investigate the relationship between the expression level of mismatch repair (MMR) genes and the risk of colorectal cancer. The relative expression of five known MMR genes, i.e., hMSH2, hMLH1, hPMS1, hPMS2, and GTBP/hMSH6, was measured by a multiplex reverse transcriptase (RT)-polymerase chain reaction (PCR) in peripheral blood lymphocytes from 31 colorectal cancer patients and 47 age- and-sex matched controls. The expression of hMSH2, GTBP/hMSH6, hPMS1 and hPMS2 tended to be lower in patients than controls, but only the difference in hPMS2 expression was statistically significant (p
Detection of ras gene mutations in peripheral blood of carcinoma patients using CD45 immunomagnetic separation and nested mutant allele specific amplification.
Shibata K. Mori M. Kitano S. Akiyoshi T.
Department of Surgery, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan.
We developed a sensitive technique of detecting circulating tumor cells in carcinoma patients, using CD45 immunomagnetic separation to isolate epithelial cells in blood samples and specific polymerase chain reaction analysis to identify point mutations of the K-ras gene. The method is based on the fact that the peripheral blood mononuclear cells (PBMC) that express CD45 antigen are trapped with anti-CD45 conjugated supramagnetic microbeads while the carcinoma cells that do not express CD45 antigen are not trapped and pass through the magnetic fields. This method concentrated the number of carcinoma cells 3.3 times. After this separation, the modified method of mutant allele specific amplification was applied and this method was able to ten control carcinoma cells in a background of 107 PBMC. A preliminary clinical study demonstrated that six cases of end-stage carcinoma with K-ras mutations in the primary tumor showed the same mutations in the peripheral blood samples, while two cases without K-ras mutation in the primary tumor and 10 healthy volunteers showed no mutation in the peripheral blood samples. The results suggest that this method may be very useful to detect circulating carcinoma cells in the patient whose primary tumor shows K-ras mutations.
No evidence for constitutional ATM mutation in breast/gastric cancer families.
Bay JO. Grancho M. Pernin D. Presneau N. Rio P. Tchirkov A. Uhrhammer N. Verrelle P. Gatti RA. Bignon YJ.
Laboratoire d'Oncologie Moleculaire, INSERM CRI 9502 and EA2145, Centre Jean Perrin, BP 392, 63011 Clermont-Ferrand cedex 1, France.
Ataxia-Telangiectasia (A-T) is a rare autosomal recessive disease characterised by cutaneous telangiectasia, cerebellar ataxia, immunodeficiency, high sensitivity to ionising radiation, chromosomal instability and an increased risk of cancer. The gene mutated in A-T patients, ATM, is located on chromosome 11q22-23. ATM heterozygotes are thought to have a high tendency to develop malignancies, such as breast cancer. In order to determine the contribution of heterozygous ATM mutation to cancer, studies of cancer-affected patients have been undertaken in non site-specific cancer families and sporadic breast cancer cases. No evidence of an important role of ATM heterozygous mutations has been shown. In order to give another contribution to these results, we tried to define a specific family phenotype according to the most common cancers observed in ATM heterozygotes. Breast and gastric cancers appear to be the most frequent malignancies in A-T carriers and one ATM germ-line mutation has been described in a breast/gastric cancer family. Therefore we further investigated the role of ATM mutation in additional breast/gastric cancer families. In eighteen families associating these two malignancies, we used the protein transcription/translation test to detect ATM mutations in the index case from each family. We found one case of ATM mutation which did not cosegregate with the gastric cancer in the family.