Jpn J Cancer Res

Geographic clustering patterns in mortality from biliary tract cancer in Japan.

Year 1998
Kodama K. Nakadaira H. Endoh K. Yamamoto M.
Department of Hygiene and Preventive Medicine, Niigata University School of Medicine.
We calculated the standardized mortality ratios (SMRs) of biliary tract cancer (BTC) in Japan from 1981 to 1990 and statistically analyzed the results according to 333 Secondary Areas of Medical Care, as well as sex and subsite [gallbladder cancer (GBC) and extrahepatic bile duct cancer (BDC)], in order to examine geographic clustering patterns of BTC. In GBC in both sexes, the Secondary Areas of Medical Care with high SMRs were clustered in the eastern part of Japan. In BDC in both sexes, the Areas with high SMRs were clustered between the northern and eastern parts of Japan. In comparison with GBC, this clustering favored the northern part of Japan. In males, the clustering pattern in mortality from BTC was mainly due to the occurrence of BDC. In females, the clustering pattern in mortality from BTC reflected that of GBC. The clustering of BTC, especially GBC, seems to be related to the distribution of plains, basins, and rivers.

Alteration of p53 clonality accompanying colorectal cancer progression.

Year 1998
Kuwabara A. Watanabe H. Ajioka Y. Yasuda K. Saito H. Matsuda K. Kijima H. Hatakeyama K.
First Department of Pathology, Niigata University School of Medicine.
The aim of this study was to clarify whether or not the status of gene alteration is heterogeneous in intramucosal carcinoma and homogeneous within invasive carcinoma. We selected 10 colorectal carcinoma cases (1 mucosal, 5 submucosal and 4 advanced carcinomas including 2 cases with lymph node metastasis) and analyzed the p53 gene sequence. Six colorectal cancers in this study showed heterogeneity in p53 mutations in cells from the intramucosal part. In the invasive part of a carcinoma, p53 mutation status was homogeneous intratumorally in all cases. These data indicate that, in regard to p53 gene alterations, colorectal cancers can be composed of various subclones when limited to the mucosa, but clonal selection occurs when one of these subclones commences invasion to the submucosa, generating a monoclonal invasive carcinoma.

Calcium, magnesium, and nitrate in drinking water and gastric cancer mortality.

Year 1998
Yang CY. Cheng MF. Tsai SS. Hsieh YL.
School of Public Health, Kaohsiung Medical College, Taiwan.
The possible association between the risk of gastric cancer and the levels of calcium, magnesium, and nitrate in drinking water from municipal supplies was investigated in a matched case-control study in Taiwan. Records of gastric cancer deaths among eligible residents in Taiwan from 1987 through 1991 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by sex, year-of-birth, and year-of-death. Each matched control was selected randomly from the set of possible controls for each case. Data on calcium, magnesium, and nitrate levels in drinking water throughout Taiwan were obtained from the Taiwan Water Supply Corporation. The municipality of residence of the cases and controls was assumed to be the source of the subject's calcium, magnesium, and nitrate exposure via drinking water. The subjects were divided into tertiles according to the levels of calcium, magnesium, and nitrate in their drinking water. The results of the present study show that there is a significant positive association between drinking water nitrate exposure and gastric cancer mortality. The present study also suggests that there was a significant protective effect of calcium intake from drinking water on the risk of gastric cancer. Magnesium also exerts a protective effect against gastric cancer, but only for the group with the highest levels.

Globotriaosyl ceramide and globoside as major glycolipid components of fibroblasts in scirrhous gastric carcinoma tissues.

Year 1998
Sawada R. Hotta H. Chung YS. Sowa M. Tai T. Yano I.
First Department of Surgery, Osaka City University Medical School, Osaka.
Scirrhous gastric cancer is characteristic in that cancer cells proliferate and invade with prominent fibrosis. To search for the expression of specific carbohydrate chains in scirrhous gastric cancer, we have examined the glycosphingolipid composition of scirrhous cancer tissues (n=10) in comparison with that of non-scirrhous cancer tissues (n=10) by means of two-dimensional thin layer chromatography, followed by fast atom bombardment mass spectrometry of the individual glycolipids and immunostaining analysis. The major neutral glycosphingolipids from scirrhous gastric cancer tissues were identified as ceramide monohexoside, ceramide dihexoside, globotriaosyl ceramide (Gb3) and globoside (Gb4), while the major acidic glycosphingolipids were II3 NeuAcalpha-LacCer, II3 NeuAcalpha2-LacCer and sulfatide. Relative concentrations of Gb3 and Gb4 in scirrhous gastric cancer tissues (Gb3 + Gb4 = 58%) were two times higher than those in non-scirrhous gastric cancer tissues (29%). Orthotopic fibroblasts cloned from scirrhous gastric cancer tissues showed similar high concentrations of Gb3 and Gb4 to scirrhous gastric cancer tissues. Furthermore, immunohistochemical study revealed that Gb3 and Gb4 were expressed intensely on the fibroblasts. On the other hand, analysis of glycosphingolipids in four scirrhous gastric cancer cell lines yielded the following results. i) The contents of Gb3 and Gb4 were low (6%), compared with orthotopic fibroblasts (62%). ii) Significant amounts of Le(a) (pentaglycosylceramide) and Le(b) (hexa- and heptaglycosylceramides), which could not be detected in scirrhous cancer tissues, were observed. The results show that the major neutral glycosphingolipids such as Gb3 and Gb4 of scirrhous gastric cancer tissues were derived from orthotopic fibroblasts and not from the cancer cells.

Homotypic adhesion through carcinoembryonic antigen plays a role in hepatic metastasis development.

Year 1998
Yoshioka T. Masuko T. Kotanagi H. Aizawa O. Saito Y. Nakazato H. Koyama K. Hashimoto Y.
Department of Surgery, Akita University School of Medicine, Hondo.
We established a cell line with high metastatic potential to the liver (LS-LM4) after four successive repetitions of splenic injection of liver-metastatic cells in SCID mice. This cell line strongly expressed CEA and showed increased homotypic adhesion as compared with the parent cell line (LS174T). To examine the role of CEA in the increased homotypic adhesion, LS-LM4 cells were treated with anti-CEA antibody and subjected to an in vitro adhesion and aggregation assay. Further, to study the role of CEA in the hepatic metastasis of cells with high metastatic potential, LS-LM4 cells were treated with anti-CEA antibody, and the inhibition of hepatic metastasis after splenic injection in vivo was examined. There was a 62% decrease in the homotypic adhesion of anti-CEA antibody-treated (100 microg/ml) LS-LM4 cells under a Ca2+-free condition as compared with the control (P

Increased expression of sucrase and intestinal-type alkaline phosphatase in human gastric carcinomas with progression.

Year 1998
Nakamura W. Inada K. Hirano K. Tsukamoto T. Inoue H. Kito K. Yoshikawa A. Nakamura S. Tatematsu M.
Laboratory of Pathology, Aichi Cancer Center Research Institute, Nagoya.
The activities of sucrase, total alkaline phosphatase (total ALP) and intestinal-type alkaline phosphatase (I-ALP) were assayed in gastric carcinomas and in their surrounding mucosae from 57 patients with advanced cancers, and the localization of sucrase in 203 carcinomas, including 86 early cancers, was examined immunohistochemically using polyclonal anti-sucrase antibody. All three enzymes were active in the 57 carcinomas as well as in their surrounding mucosae, but the levels were fairly low as compared to those in normal jejunum mucosa. A considerable part of the total ALP activity in tumor specimens was assumed to be due to I-ALP itself. Increased sucrase and I-ALP were found with greater depth of invasion by undifferentiated-type carcinomas. The pattern of immunohistochemical localization of sucrase in the 203 carcinomas also clearly indicated increased expression with greater depth of invasion even in differentiated-type carcinomas.

Establishment of Epstein-Barr virus-positive human gastric epithelial cell lines.

Year 1998
Tajima M. Komuro M. Okinaga K.
Central Clinical Laboratory, Teikyo University School of Medicine, Tokyo.
We have established two Epstein-Barr virus (EBV)-positive cell lines, GT38 and GT39, derived from human gastric tissues of two patients bearing gastric carcinoma. Both cell lines were positive for cytokeratin, an epithelial marker, but not for lymphocyte-related markers. Unlike GT39 cell line, GT38 cells lacked the property of contact inhibition. EBV genome was detected in both cell lines. The cell lines were positive for latent membrane protein 1, and EBV-determined nuclear antigen 1 (EBNA1). EBNA2 was also detected in GT38. These cell lines should be useful for studying the interaction of EBV with gastric epithelial cells and its role in gastric carcinogenesis.

Loss of pS2 protein expression is an early event of intestinal-type gastric cancer.

Year 1998
Wu MS. Shun CT. Wang HP. Lee WJ. Wang TH. Lin JT.
Department of Internal Medicine, National Taiwan University Hospital, Taipei.
To investigate the prevalence of pS2 expression in gastric cancer with respect to tumor histopathology, intestinal metaplasia and Helicobacter pylori (H. pylori) infection, pathologic specimens of 91 patients with gastric cancer were immunostained for pS2. Such immunoreactivity was correlated with the status of H. pylori infection, tumor staging, histology, subtyping, and associated intestinal metaplasia. Positive pS2 staining was seen throughout all non-neoplastic epithelia, and in all 9 patients with the complete type of intestinal metaplasia. In contrast, 21 of 45 incomplete type of intestinal metaplasia had negative pS2 staining (P < 0.001), and 54 out of 91 tumors (59.3%) showed loss of pS2 expression in the cancer tissues proper. There was no correlation of pS2 expression with age, gender, depth of invasion, duodenal involvement, lymph node metastasis, venous invasion or H. pylori infection. Negative pS2 staining was significantly higher in the intestinal (74.5%) and Borrmann type I, II, III (64.2%) tumors than the diffuse (43.2%, P < 0.005) and Borrmann type IV (20%, P < 0.05) tumors. Our results indicate that loss of pS2 expression may occur as an early event in the malignant transformation process of intestinal-type tumors.

Genetic alterations of mixed hyperplastic adenomatous polyps in the colon and rectum.

Year 1998
Uchida H. Ando H. Maruyama K. Kobayashi H. Toda H. Ogawa H. Ozawa T. Matsuda Y. Sugimura H. Kanno T. Baba S.
Department of Laboratory Medicine, Hamamatsu University School of Medicine.
Some mixed hyperplastic adenomatous polyps (MHAPs) contain dysplastic lesions or even carcinomas. These polyps are considered to be different from ordinary hyperplastic polyps and may have a preneoplastic potential. We investigated APC and K-ras mutations in MHAPs of the colon and rectum, and also in colorectal adenomas and hyperplastic polyps to identify molecular differences between MHAPs, adenomas and hyperplastic polyps, using direct sequencing of mutation cluster regions (MCR) in APC and K-ras. No APC mutations were identified in 12 MHAPs and 8 hyperplastic polyps, whereas 10 of 27 (37.0%) adenomas showed somatic mutations. K-ras mutations were identified in one of 12 (8.3%) MHAPs, one of 8 (12.5%) hyperplastic polyps, and 10 of 27 (37.0%) adenomas. p53 mutation was found in a carcinoma arising in an MHAP. Mutations other than APC mutations may play a role in the development of MHAPs.

Increased sensitivity to long-term 5-fluorouracil exposure of human colon cancer HT-29 cells resistant to short-term exposure.

Year 1998
Inaba M. Tanaka T. Sawada H.
Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo.
A 5-fluorouracil (5-FU)-resistant subline of human colon cancer HT-29 cells was developed by repeated 1-h exposure in vitro to 5-FU. This subline (HT-29/5-FU/S) had 8-fold resistance to 5-FU in a 1-h exposure assay. However, it had rather increased sensitivity to 5-FU when assayed after a continuous 96-h exposure to it. Significantly less 5-fluorouridine-5'-triphosphate was produced in the resistant cells, leading to a lower level of 5-FU incorporation into the cellular RNA. The reduced activity of orotate phosphoribosyltransferase might explain these results. In contrast, the HT-29/5-FU/S cells were more sensitive to the inhibition of in situ thymidylate synthase (TS) by 5-FU than were the parent cells. The lower in situ TS activity may have made HT-29/5-FU/S cells more sensitive to TS inhibition by 5-FU as compared with the parent cells. The fact that HT-29/5-FU/S was more resistant to short-term 5-FU exposure but more sensitive to long-term exposure than the parent line confirmed the existence of different modes of action of 5-FU, depending on the exposure time.

Heterogeneity of p53 mutational status in esophageal squamous cell carcinoma.

Year 1998
Kuwabara S. Ajioka Y. Watanabe H. Hitomi J. Nishikura K. Hatakeyama K.
First Department of Pathology, Niigata University School of Medicine.
In esophageal squamous cell carcinoma, p53 gene mutations have been analyzed for inter- or intra-patient heterogeneity but only a few studies have investigated intratumoral heterogeneity. We investigated this question within individual esophageal cancers, and also in their lymph-node metastases in 8 cases. Analyzing the p53 gene sequence by direct sequencing of polymerase chain reaction products, we found heterogeneity for p53 mutations in the pre-invasive area in 3 esophageal cancers. In all areas sampled in the invasive portion of each cancer, the p53 mutational status was identical in a given tumor. In heterogeneous tumors, the invasive area showed one of the p53 mutations found in the pre-invasive area. In nodal metastases, the p53 mutation was identical to that in the invasive area of each primary tumor. These data suggest that the timing of p53 alteration is not as early as might have been expected, indicating that, in regard to p53 gene alteration, some esophageal cancers are composed of various subclones in the pre-invasive stage with invasiveness developing in one of them, which becomes predominant through clonal selection.

Clinicopathological criteria for multicentricity of hepatocellular carcinoma and risk factors for such carcinogenesis.

Year 1998
Kubo S. Nishiguchi S. Hirohashi K. Shuto T. Kuroki T. Minamitani S. Ikebe T. Yamamoto T. Wakasa K. Kinoshita H.
Second Department of Surgery, Osaka City University Hospital.
Multicentric occurrence is an important characteristic of hepatocellular carcinoma. We evaluated clinicopathological criteria for multicentric hepatocellular carcinoma and identified risk factors for such carcinogenesis. Subjects were 251 consecutive patients undergoing liver resection for hepatocellular carcinoma. One kind of multicentric hepatocellular carcinoma had at least one tumor consisting of well-differentiated hepatocellular carcinoma, together with moderately or poorly differentiated hepatocellular carcinoma located in a separate region. The other kind had an area of well-differentiated component around hepatocellular carcinoma with less differentiation in all occurrences. The outcome of patients with tumors classified in this way was studied. Univariate and multivariate analyses were done to identify risk factors for multicentric hepatocellular carcinoma. The cumulative survival rate was significantly higher in patients with multicentric hepatocellular carcinoma than in patients with hepatocellular carcinoma associated with intrahepatic metastasis. Analysis by Cox's proportional hazard model showed that multicentricity was not a factor in the outcome. The risk of multicentric occurrence increases with progression of chronic liver disease. Univariate analysis showed hepatitis C virus marker and hepatitis B core antibody to be risk factors. By multivariate analysis, the odds ratio for multicentric occurrence in patients infected with hepatitis C virus and with serum hepatitis B virus core antibody compared with patients without either hepatitis C virus or hepatitis B virus was 10.86. This ratio in patients with hepatitis C virus alone was 4.30. These criteria for multicentric hepatocellular carcinoma seem to be clinically useful. Hepatitis C virus infection with or without former infection by hepatitis B virus is a strong risk factor for multicentric hepatocarcinogenesis.

In vivo adenovirus-mediated prodrug gene therapy for carcinoembryonic antigen-producing pancreatic cancer.

Year 1998
Ohashi M. Kanai F. Tanaka T. Lan KH. Shiratori Y. Komatsu Y. Kawabe T. Yoshida H. Hamada H. Omata M.
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo.
In gene therapy for malignancy, the herpes simplex virus thymidine kinase (HSVtk)-ganciclovir (GCV) system has been widely used. For pancreatic cancer targeting, we estimated the therapeutic efficacy of gene transduction by an adenovirus-carrying HSVtk gene under the control of a carcinoembryonic antigen (CEA) promoter (AdCEAtk) followed by systemic administration of GCV. Four cell lines, CEA-producing Su.86.86. BxPC-3 (pancreatic cancer cells), MKN45 (gastric cancer cells) and CEA-nonproducing HeLa, were used for analysis of GCV sensitivity induced by adenoviral gene transduction. To evaluate the therapeutic efficacy of AdCEAtk and GCV administration in human CEA-positive pancreatic cancer in vivo, a subcutaneously implanted tumor-bearing nude mouse model was used. When the HSVtk gene was transduced with a ubiquitous promoter into these cells, increase of the GCV sensitivity was independent of CEA-production. In contrast, when the cells were transduced with a CEA promoter, the cell-killing effect of GCV was increased in only CEA-producing cells. For in vivo analysis, AdCEAtk was delivered into subcutaneously established tumors of Su.86.86 cells. Immunohistochemical staining of the tumor showed that HSVtk protein was expressed only in tumor cells, and tumor growth was markedly suppressed by administration of GCV. These results suggest that the adenovirus-mediated transfer of HSVtk gene with CEA promoter specifically increases the GCV sensitivity of CEA-producing pancreatic cancer cells in vitro and in vivo. This strategy may provide a useful tool for treating pancreatic cancer, especially CEA-producing tumor cells.