bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory Effect of a Somatostatin Analogue (SMS 201–995) on the Growth of Androgen‐dependent Mouse Mammary Tumor (Shionogi Carcinoma 115)
Authors: Noguchi Shinzaburo , Nishizawa Yasuko , Motomura Kazuyoshi , Inaji Hideo , Imaoka Shingi , Koyama Hiroki , Matsumoto Keishi
Published: August 2005

The influence of a soinatostatin analogue, SMS 201–995 (SMS), on the growth of an androgen‐dependent mouse mammary tumor, Shionogi carcinoma 115 (SC115), was studied. Treatment of SC11S tumor‐transplanted male mice with s.c. injections of SMS (0.04, 0.2,1, and 5 μg twice a day) resulted in a dose‐dependent inhibition of tumor growth. The growth‐inhibitory effect of SMS reached its peak at a dose of 1 μg twice a day. SMS was found not to elicit its growth‐inhibitory effect through lowering plasma testosterone levels or down‐regulating androgen receptor of SC115 tumors. Since specific binding sites for somatostatin were not observed in the membrane fractions of SC115 tumors and SMS did not inhibit the proliferation of primarily cultured SC115 tumor cells, a direct inhibitory mechanism of SMS on SC115 tumors was unlikely to be operative. Since SMS is a very potent inhibitor of growth hormone (GH) secretion, it was speculated that SMS might inhibit the growth of SC115 tumors indirectly through down‐regulation of plasma GH levels. This possibility was evaluated by studying the influence of GH replacement on the growth of SC115 tumors grown in SMS‐treated mice. GH replacement was done both in a male secretory pattern (intermittent injection, human GH 500 μg/kg twice a day) and in a female secretory pattern (continuous infusion, 1000 μg/kg/day). Intermittent injections of GH fully restored the growth of SC115 tumors in the SMS‐treated mice to that in the normal controls but continuous infusion of GH was without effect. These results suggest that SMS inhibits the growth of SC115 tumors through suppression of GH secretion, and that the mode of GH administration is an important determinant of its action on SC115 tumor growth.
Cellular Stress‐ and Transformation‐associated Cell Surface Antigens Expressed on Human and Rodent Tumor Cells
Authors: Torigoe Toshihiko , Tsuboi Norioki , Wada Yoshimasa , Qi Weimin , Ohtani Seiji , Kishi Akihiko , Sato Noriyuki , Kikuchi Kokichi
Published: August 2005

Stress‐induced proteins may have significant roles in anti‐tumor resistance. To clarify the immunobiological roles of these proteins, we first developed monoclonal antibody (mAb) H1A that detects the HeLa cell‐surface antigens whose expression was enhanced by treatment of the cells with physico‐chemical stressors, such as heat, H2O2 and tumor necrosis factor. H1A (IgM) detects several molecules with mol. wt. 30, 43, 75, 90, 100, 120 and 150 kDa in Western blot analysis of HeLa cell lysates. Although the antigen was constitutively expressed on the HeLa cell surface, the cell‐surface expression of H1A‐defined antigen was rapidly enhanced (within 1 h) after heat treatment of HeLa cells. H1A antigens were also transformation‐associated, since 1) the activated oncogene‐transformed fibroblasts expressed the antigens, but parental nontransformed cells did not, and 2) certain human neoplastic but not normal cells strongly expressed the antigens. Furthermore, H1A mAb also partly blocked the cytotoxicity of purified protein derivatives‐stimulated human T cell receptor γδ‐type T cells towards HeLa cells. Taken together, these data indicate that H1A‐defined stress‐inducible proteins may play a vital role in anti‐tumor resistance by cytotoxic T cells.
Chemiluminescence Immunoassay to Detect Anti‐HTLV‐I Antibodies
Authors: Kamihira Shimeru , Nakashima Shigehiro , Saitoh Shin , Kawamoto Michiko , Kawashima Yumiko , Shimamoto Mitoshi
Published: August 2005

A fully automated chemiluminescence immunoassay was developed for the detection of antibodies to HTLV‐I. We used partially purified viral antigens coated on small polystyrene beads together with acridinium ester‐labeled anti‐human immunoglobulin G mouse immunoglobulin G in this method. A good agreement was observed between our proposed method, the indirect immunofluorescence assay, the particle‐agglutination test and the enzyme immunoassay. This new method, which is simple, sensitive, specific and rapid, should be useful for mass screening of anti‐HTLV‐I antibodies.
Does High Gastric Cancer Risk Associated with Low Serum Ferritin Level Reflect Achlorhydria? An Examination via Cross‐sectional Study
Authors: Kabuto Michnori , Imai Hideki , Tsugane Shoichiro , Watanabe Shaw
Published: August 2005

With respect to the inverse association of serum ferritin level (SFL) with the risk of gastric cancer (GC) observed in some recent epidemiologic studies, possible mediation by achlorhydria as well as atrophic gastritis (AG), both of which are strongly associated with GC risk at not only the individual but also the population level, was examined in a cross‐sectional study of 634 men aged 40 to 49 years randomly selected from 5 populations in Okinawa, Iwate, Nagano, Akita and Tokyo. AG and achlorhydria were serologically diagnosed based on the criteria of pepsinogen (Pep) I level <70 ng/ml and Pep I/Pep II ratio <3.0, as described previously, and a serum gastrin level of over 140 pg/ml, respectively. In the results, while the mean SFL for all the subjects differed significantly by area, similar areal differences in SFL were also found even when only the non‐AG cases were considered. However, both of the above differences were eliminated with the exception of those between Okinawa and each of the other 4 areas, when adjustments were made for medical histories of diabetes mellitus, ulcers and liver disease, body mass index and γ‐glutamyltranspeptidase level. Therefore, no correlation among the 5 areas was observed between the adjusted areal mean SFLs and GC mortality in either case. However, in 17 (45%) achlorhydric cases identified among the 38 subjects with severe AG, which were further discriminated with stricter criteria (Pep I <30 ng/ml and Pep I/Pep II ratio <2.0), their averaged SFL was significantly lower than the values for the non‐AG cases (3.78 vs. 4.64 In(ng/ml), P<0.001) and mild/moderate AG cases (3.78 vs. 4.47 ln(ng/ml), P<0.01), while the differences were not significant with respect to the other 21 (55%) severe AG cases without achlorhydria. Thus, it is suggested that the negative association of SFL, for which no mechanism has been shown in cancer etiology, with GC risk is indirect, since both of them are associated primarily with achlorhydria found among the severe AG cases. Moreover, areal mean SFLs, which are not determined only on the basis of the prevalence of achlorhydric AG cases, could not be related to GC mortality rates, suggesting that no direct association exists at the population level either.
The Rat Urinary Bladder as a New Target of Heterocyclic Amine Carcinogenicity: Tumor Induction by 3‐Amino‐l‐methyl‐5H‐pyrido[4,3‐β]indole Acetate
Authors: Takahashi Michihito , Toyoda Kazuhiro , Aze Yoshiya , Furuta Kyoko , Mitsumori Kunitoshi , Hayashi Yuzo
Published: August 2005

In order to examine the carcinogenicity of 3‐amino‐l‐methyl‐5H‐pyrido[4,3‐β]indole acetate (Trp‐P‐2), 30 male and 30 female F344 rats were maintained on diet containing 0, 30, or 100 ppm Trp‐P‐2 for 112 weeks. The overall mean chemical intakes in the 100 ppm and 30 ppm groups were 3.84 and 1.14 mg/kg/day in males, and 4.57 and 1.34 ing/kg/day in females, respectively. Females of the 100 ppm group showed increased mortality in the late period of the study. In the 100 ppm group, significant increases in the incidences of neoplastic lesions were found in the liver, urinary bladder and mammary gland in males, and in the mammary gland, hematopoietic system and clitoral gland in females. Histologically, tumors induced by Trp‐P‐2 were hepatocellular adenomas, transitional cell tumors (papillomas and carcinomas) of the urinary bladder, fibroadenomas/fibromas of the mammary gland, malignant lymphomas and clitoral gland tumors (adenomas and adenocarcinomas). These results indicate multi‐target carcinogenicity of Trp‐P‐2 in F344 rats and provide evidence that the urinary bladder is also a target for heterocyclic amine action.
Effects of Chronic Administration of Low Doses of 2‐Ammo‐3,8‐dimethylimidazo‐[4,5‐f]qumoxaline on Glutathione S‐Transferase Placental Form‐positive Foci Development in the Livers of Rats Fed a Choline‐deficient Diet
Authors: Sone Hideko , Wakabayashi Keiji , Kushida Hiromi , Ochiai Masako , Sugimura Takashi , Nagao Minako
Published: August 2005

Effects of chronic administration of 2‐amino‐3,8‐dimethylimidazo[4,S‐f]quinoxaline (MeIQx) at the very low doses of 0.4 and 4 ppm, respectively 1000‐ and 100‐fold less than the dose shown to be carcinogenic (400 ppm), on the liver of rats fed a choline‐deficient (CD) diet were examined in terms of glutathione S‐transferase placental form (GST‐P)‐positive foci. Male F344 rats were given CD diet containing 0, 0.4 or 4 ppm MeIQx for 20 or 40 weeks. As controls, rats received choline‐supplemented (CS) diet in the same manner. MeIQx at 4 ppm in the CD diet significantly increased both the number and area of GST‐P‐positive foci, the values being 2.3‐ and 2.1‐fold at 20 weeks and 2.0‐ and 3.3‐fold at 40 weeks, respectively, compared with those observed for CD diet alone. MeIQx at 0.4 ppm in CD diet did not affect the development of GST‐P‐positive foci. No influence of the heterocyclic amine was found in the CS groups, where only very small numbers of minute lesions were observed. The level of MeIQx‐DNA adducts in rats given the CD diet containing 4 ppm MeIQx was 2‐ to 3‐fold lower than that in rats given the CS diet containing 4 ppm MeIQx at 20 and 40 weeks. This result indicates that DNA adduct formation and cell proliferation are both required for the increase of GST‐P‐positive foci in rats fed 4 ppm MeIQx in a CD diet. The above findings strongly suggest that MeIQx could be carcinogenic even at 4 ppm under CD conditions, where liver cell regeneration is continuously occurring.
Genetic Changes and Histopathological Grades in Human Hepatocellular Carcinomas
Authors: Konishi Motoko , Kikuchi‐Yanoshita Rei , Tanaka Kiyoko , Sato Chieko , Tsuruta Kouji , Maeda Yoshiharu , Koike Morio , Tanaka Satoshi , Nakamura Yusuke , Hattori Nobu , Miyaki Michiko
Published: August 2005

Loss of heterozygosity (LOH) on chromosomes 1p, 4q, 5q, 8p, 13q, 16q, 17p, and 22q, and mutation of the p53 gene were simultaneously analyzed in 63 hepatocellular carcinomas (HCCs) with distinct histopathological grades, 80% of the tumors being from patients who had been exposed to hepatitis B virus (HBV) or hepatitis C virus (HCV). The frequencies of LOH on 8 chromosomes were 0–25% in 10 well differentiated HCCs, LOH being observed on 4q, 5q and 17p, 21–53% in 26 moderately differentiated HCCs, LOH on 8p and 17p being high, and 29–75% in 27 poorly differentiated HCCs, LOH on 17p, 4q and 8p heing the most frequent. p53 gene mutation was detected in moderately and poorly differentiated HCCs at 15% and 52%, respectively, but not at all in well differentiated HCCs. Of the mutations detected, 42% were transition mutation and only 5% were CpG transition, in contrast to the high frequencies of these types of mutations in colon tumors (78% and 54%, respectively). LOH on every chromosome and p53 mutation were more frequent in more advanced tumors, and accumulation of genetic changes increased with increase of the histopathological grade. Frequency of genetic changes in HCCs from HBV‐positive patients was comparable to that from HCV‐positive patients. The present results suggest that accumulation of genetic changes in multiple tumor suppressor genes, especially LOH on 17p, 4q and 8p, and mutation in p53 gene, are involved in the progression of liver cancer, and LOH on 17p and 4q precedes other genetic changes. Differences in the direction of p53 mutation between HCC and colon carcinoma suggest that liver carcinogens are distinct from colon carcinogens. Furthermore, mechanisms affecting the frequency of LOH in HCCs in HBV‐infected patients may be similar to those in HCV‐infected patients.
Infiltrating Lymphocytes and Accessory Cells in Nasopharyngeal Carcinoma1
Authors: Zong Yong‐sheng , Zhang Chang‐qing , Zhang Feng , Kuan Jian‐bo , Chen Mo‐ye , Feng Kai‐tao , Yu Zhao‐fang
Published: August 2005

The infiltrating lymphocytes (LCs) and accessory cells (ACs) including dendritic cells (DCs) and monocytes/macrophages in nasopharyngeal biopsies taken from 4 groups of nasopharyngeal carcinoma (NPC) patients were observed by using an immunostaining technique and the correlation of the results to the clinical manifestations and follow‐up data was examined. The findings were as follows. (1) NPCs without lymph node metastasis always had marked infiltrating LCs and DCs as compared with those with lymph node(s) metastasis. (2) Advanced NPCs with lymph node(s) involvement (T1–4N1–3M0) and a rapid development of distant metastasis followed by death within 1 year after radiotherapy always showed fewer infiltrating LCs and DCs as compared with those with lymph node(s) metastasis (T1–4N1–3M0) and having longer than 5‐year survival after radiotherapy. The amount of both LCs and ACs, especially DCs, infiltrating in NPC tissues appears to be an indicator of the activity of host immune defence mechanisms against cancer and influences the progression of the neoplasm as well as the prognosis.
Southernmost Carriers of HTLV‐I/II in the World
Authors: Cartier Luis , Araya Fernando , Castillo Jose Luis , Zaninovic Vladimir , Hayami Masanori , Miura Tomoyuki , Imai Joko , Sonoda Shunro , Shiraki Hiroshi , Miyamoto Kanji , Tajima Kazuo
Published: August 2005

To clarify the real distribution of HTLV‐I and ‐II carriers among indigenous people in central and South America, blood samples collected from indigenous people in isolated regions of Southern Chile were examined. Among 199 inhabitants from Chiloe Island and Pitrufquen town, three cases (1.5%) showed positive anti‐HTLV‐I antibodies. Two out of the three (82‐year‐old male and 58‐year‐old female) reacted to HTLV‐II‐specific Gag and/or Env proteins but not to HTLV‐I‐specific ones. The latter case was confirmed as an HTLV‐II carrier by polymerase chain reaction test.
Differential Alterations of Dihydrofolate Reductase Gene in Human Leukemia Cell Lines Made Resistant to Various Folate Analogues
Authors: Miyachi Hayato , Takemura Yuzuru , Kobayashi Hiroyuki , Ando Kiyoshi , Ando Yasuhiko
Published: August 2005

In order to clarify a molecular mechanism of folate resistance in leukemia cells, we studied alterations of the dihydrofolate reductase (DHFR) gene in a human leukemia cell line, MOLT‐3, and its sublines made resistant to methotrexate (MTX), trimetrexate (TMQ) and N10‐propargyl‐5,8‐dideazafolic acid (CB3717), alone or in combination. Major alterations of the DHFR gene were examined by Southern analysis of high‐molecular‐weight DNA. The presence of a base change (T→C) at nucleotide position 91 of the DHFR gene, which is reported to be responsible for the reduced affinity of the enzyme for MTX in an MTX‐resistant human colon carcinoma cell, was examined by allele‐specific oligonucleotide hybridization. In a 10,000‐fold MTX‐resistant subline (MOLT‐3/MTX10,000), the normal allele of DHFR gene had been amplified. In contrast, a 200‐fold TMQ‐resistant subline (MOLT‐3/TMQ200) and a 30‐fold CB3717‐resistant subline selected from MOLT‐3/TMQ200 (MOLT‐3/TMQ200‐CB‐371730) were shown to have the mutant allele. Furthermore, the mutant allele had been amplified in a 500‐fold MTX‐resistant subline, which was established by the continuous exposure of the MOLT‐3/TMQ200 cells to stepwise increases of drug concentration and designated as MOLT‐3/TMQ200‐MTX500. On the other hand, a 40‐fold‐resistant subline to CB3717 alone (MOLT‐3/CB371740) showed the normal allele without amplification. These data suggest that complex alterations of the DHFR gene are involved in the molecular mechanisms of folate resistance that can be differentially introduced into leukemia cells by exposure to various folate analogues, alone or in combination.
Relationship of Diet to Small and Large Adenomas of the Sigmoid Colon
Authors: Kono Suminori , Imanishi Koji , Shinchi Koichi , Yanai Fumio
Published: August 2005

The relation of dietary factors to the risk of adenomas of the sigmoid colon was examined in men receiving a retirement health examination at the Self‐Defense Forces Fukuoka Hospital between October 1986 and 1990. A total of 187 adenoma cases and 1557 controls with normal colonoscopy were identified in the series. Cases were further classified into small‐adenoma (<5 mm, n=78) and large‐adenoma (≥5 mm, n=67) groups. The consumptions of selected foods and beverages were ascertained before colonoscopy by means of a self‐administered questionnaire. After adjustment for smoking, alcohol use, rank and body mass index, low rice consumption and high meat intake were independently associated with an increased risk of large adenomas. The risk of small adenomas was not related to either rice consumption or meat intake. Adjusted odds ratios of large adenomas for the low, intermediate and high consumption levels of rice were estimated to be 1.0 (referent), 0.83 and 0.43, respectively (trend P= 0.08), and the corresponding figures for meat consumption were 1.0 (referent), 1.58 and 2.38, respectively (trend P=0.02). The findings suggest that low rice consumption and high meat intake may promote the growth of colon adenomas, thereby increasing the risk of colon cancer.
Effect of an Inhibitor of Tumor Promotion, α‐Difluoromethylornithine, on Tumor Induction by Repeated Beta Irradiation in Mice
Authors: Ootsuyama Akira , Tanooka Hiroshi
Published: August 2005

α‐Difluoromethylornithine (DFMO) is an inhibitor of putrescine biosynthesis and of tumor promotion. Studies were made of its effect on induction of skin and bone tumors by repeated beta irradiation of the back of female ICR mice 3 times weekly at a dose of 3 Gy per exposure. When given at a concentration of 10 mg/ml in the drinking water, DFMO significantly delayed the time of tumor emergence and decreased the yield of skin tumors, although the cumulative tumor incidence computed by the Kaplan‐Meier method finally reached 100%. These results indicate that tumor‐promoting activity is involved in repeated beta irradiation, besides its tumor‐initiating activity.
bcl‐2 Gene Rearrangement Analysis of Japanese Follicular Lymphomas by Polymerase Chain Reaction in Formalin‐fixed, Paraffin‐embedded Tissue Specimens
Authors: Mitani Shoko , Aoki Naoto , Mizutani Shuki , Fujiwara Mutsunori , Kitagawa Tomoyuki , Uehara Toshitaka , Mori Shigeo
Published: August 2005

The prevalence of chromosomal translocation t(14;18) was examined in 41 cases of follicular lymphoma covering all histopathological subtypes, using the polymerase chain reaction and hybridization method with non‐radioactive oligonucleotide probes. DNAs were extracted from unfixed fresh‐frozen and/or formalin‐fixed paraffin‐embedded biopsy specimens. The t(14;18) chromosomal translocation, resulting in bcl‐2‐JH (immunoglobulin heavy chain gene joining segment) fusion gene, was detected in 7 (36.8%) of 19 follicular small cleaved cell lymphomas and 6 (54.5%) of 11 follicular mixed, small cleaved cell and large cell lymphomas. Meanwhile, 11 cases of follicular large cell lymphoma revealed no bcl‐2‐JH fusion gene. There was a statistically significant difference in the frequency of bcl‐2‐JH rearrangement between follicular, small cleaved cell and large cell lymphoma (two‐sided Fisher exact test, P= 0.049). The difference of bcl‐2 rearrangement frequency between follicular, mixed and large cell lymphoma was also statistically significant (P= 0.012).
Artificial Pneumothorax as a Risk Factor for Development of Pleural Lymphoma
Authors: Aozasa Katsuyuki , Ohsawa Masahiko , Iuchi Keiji , Tajima Kazuo , Komatsu Hikotaro , Shimoyama Masanori
Published: August 2005

An etiologically important role of chronic tuberculous empyema for development of plenral lymphocytic lymphoma of B‐cell type has been suggested. To examine risk factors for development of pleural lymphoma in patients with chronic tuberculous empyema, a case‐control study was carried out. Onset age of lung tuberculosis and empyema, presence of chemotherapy, surgical treatment, extent of empyema, presence of fistula, history of smoking, and height and weight of patients at first admission were compared in patients with empyema alone (70 controls) and empyema complicated with lymphoma (42 cases): the date of birth and sex were matched by group. The patients receiving artificial pneumothorax showed a significant increase in risk for development of pleural lymphoma (relative risk = 4.92, P<0.05). We could not find any report describing development of pleural neoplasias in patients with chronic empyema receiving surgical resection of pleural pyogenic membrane. From these findings, it is suggested that artificial pneumothorax left chronic non‐healing inflammation in the pleural cavity, which resulted in development of pleural lymphoma.
T Cell Response to Embryonal Carcinoma F9 Cells: Induction and Characterization of T Cell Receptor αβ+ Double‐negative Cytotoxic T Lymphocytes
Authors: Imada Mie , Fujimoto Shigeyoshi
Published: August 2005

We investigated the mechanism of T cell response to marine embryonal carcinoma F9 cells. Thy‐1+, CD4−, CD8− (double‐negative) cytotoxic effector cells were induced in spleen cells obtained from immune A.BY mice to F9 cells, and the cytotoxic activity was major histocompatibility complex (MHC)‐unrestricted. Furthermore, CD4+ T cells were essential for the induction of double‐negative cytotoxic T lymphocytes directed to F9 cells. Most of the double‐negative cytotoxic T lymphocyte lines obtained by long‐term culture of the effector cells had CD3 molecule and T‐cell receptor β chain on their cell surface, and the CDS molecule was found to be involved in target cell recognition. The T cell receptor αβ+ double‐negative cytotoxic T lymphocyte line (2A5) also lysed various tumor cells in a non‐MHC‐restricted manner, but did not lyse concanavalin A‐stimulated blasts of 129 strain, from which F9 cells had originated. These results indicate that T cell receptor αβ+ double‐negative cytotoxic T lymphocytes induced by F9 cells recognize a common antigen(s) expressed on F9 cells and other tumor cells but not minor histocompatibility antigens.
Characterization of OM‐B Monoclonal Antibody‐defined Antigen Associated with Mucinous Type Human Ovarian Tumor
Authors: Nishida Keiko , Ueda Ryuzo , Sakakibara Katsumi , Minoura Yasushi , Ohta Masahiro , Ariyoshi Yutaka , Takahashi Toshitada
Published: August 2005

Partial characterization of the OM‐B antigen associated with mucinous‐type ovarian tumors was conducted. This antigen was defined by OM‐B monoclonal antibody, which was raised against a mucinous‐type ovarian tumor, and was present in all the mucinous‐type tumors tested, but only a fraction of serous‐type tumors. The OM‐B crude antigen preparation fractionated from cystic fluids had a density of 1.40–1.43 g/ml, with a high neutral sugar content. Molecular mass (Mr) estimated by gel filtration was more than 2,000,000. Trypsinization of the antigen preparation under appropriate conditions resulted in two major bands and one minor band with molecular sizes of less than Mr 250,000, as detected by immunoblotting. Immunoaffinity chromatography was then conducted and the amino acid composition of the purified product was determined; the high contents of serine, threonine and proline are characteristic of a mucin. Binding inhibition enzyme‐linked immunosorbent assay was developed to measure OM‐B antigen activity in cystic fluids and sera from patients with mucinous‐type tumors. The antigen was easily detected in most cystic fluids, but not in sera, suggesting that improvement in the sensitivity of this assay is necessary before its utilization for serum diagnosis will be feasible.
Analysis of DNA Fragmentation in Human Uterine Cervix Carcinoma HeLa S3 Cells Treated with Duocarmycins or Other Antitumor Agents by Pulse Field Gel Electrophoresis
Authors: Okamoto Akihiko , Okabe Masami , Gomi Katsushige
Published: August 2005

Pulse field gel electrophoresis using a contour‐clamped homogeneous electric field was applied for the analysis of DNA‐fragmenting activity of antitumor agents towards human uterine cervix carcinoma HeLa S3 cells. Duocarmycins (DUMs), novel antitumor antibiotics with ultrapotent cell growth‐inhibitory activities, caused DNA fragmentation at 10 times their IC50 values at 2 h exposure. At 100 times their IC50 values, the size of the smallest fragments was about 245 kilobase pairs (kbp). DUMA, DUMB1 and DUMB2 exhibited similar DNA fragmentation patterns, suggesting similar action mechanisms. DNA fragmentation was also detected in cells treated with radical producers, intercalators and topoisomerase inhibitors. Two bands of about 1800 and 1500 kbp were commonly detected in the cells treated with DUMs and these agents. In addition, fragments of about 900 kbp were detected in the cells treated with a topoisomerase inhibitor, 4′‐(9‐acridinylamino)methane‐sulfon‐m‐anisidine, and fragments in the broad size range between 700 and 245 kbp in the cells treated with radical producers, bleomycin and neocarzinostatin. DUMs showed a characteristic DNA fragmentation pattern, since both types of fragments induced by the topoisomerase inhibitor and the radical producers were simultaneously detected, suggesting a novel mode of interaction with DNA. DNA‐crosslinking agents and mitotic inhibitors did not induce DNA fragmentation under these conditions. The pulse field gel electrophoresis is potentially useful for characterizing DNA‐cleaving activity of various antitumor agents at the cellular level.
Influence of Esculetin on Incidence, Proliferation, and Cell Kinetics of Mammary Carcinomas Induced by 7,12‐Dimethylbenz[α]anthracene in Rats on High‐ and Low‐fat Diets
Authors: Noguchi Masakuni , Kitagawa Hirohisa , Miyazaki Itsuo , Mizukami Yuji
Published: August 2005

The effects of a high‐fat diet and esculetin were investigated on 7,12‐dimethylbenz[α]anthracene (DMBA)‐induced mammary carcinogenesis in female Sprague‐Dawley rats. Rats were given a 5‐mg dose of DMBA. Seven days later, they were fed either a high‐fat (20% soybean oil) or low‐fat (0.5% soybean oil) diet. A half of the rats received diets containing 0.03% esculetin. Esculetin significantly inhibited tumor incidence, growth and cell kinetics of the tumor in the rats fed the high‐fat and the low‐fat diets. Our findings indicate that DMBA‐induced mammary tumorigenesis is affected by lipoxygenase products.
Absence of Linkage between the Retinoblastoma Gene and hts Gene in the LEC Rat: A Model of Human Wilson's Disease
Authors: Sasaki Nobuya , Hayashizaki Yoshihide , Kasai Noriyuki
Published: August 2005

The LEC rat is an authentic model of human Wilson's disease (WD) with an autosomal recessively inherited hepatitis. We investigated linkage between the hepatitis gene (hts) and the rat retinoblas‐toma gene (RB), that is closely linked to the WD gene in humans, to see whether or not the hts gene is located on the syntenic region of WD and is the counterpart of the WD gene. Polymerase chain reaction‐single strand conformation polymorphism analysis with backcross progenies from LEC and TM strains showed that the recombination rate between these two loci was 55.6%, demonstrating that the hts and RB genes are not linked to each other. These data indicate that the hts gene is not the counterpart of the WD gene and that the human syntenic region on which the WD locus and human RB gene are located, is not conserved in the rat genome.
Growth Dependence of Human Papillomavirus 16 DNA‐positive Cervical Cancer Cell Lines and Human Papillomavirus 16‐Transformed Human and Rat Cells on the Viral Oncoproteins
Authors: Watanabe Sumie , Kanda Tadahito , Yoshiike Kunito
Published: August 2005

The dependence on human papillomavirus (HPV) Oncoproteins of the growth of cervical cancer cell lines [C4‐1, HeLa (both containing HPV 18 DNA), CaSki and SiHa (both containing HPV 16 DNA)], HPV 16‐transformed human embryonic kidney cells, and HPV 16‐transformed rat brain and 3Y1 cells was examined by using antisense RNA approaches. The cells were transfected with plasmids expressing RNA antisense to the HPV 16 or 18 open reading frames E6E7, together with plasmids expressing the hygromycin B resistance gene, and drug‐resistant colonies were scored three weeks later. In all the human cell lines, the efficiency of colony formation was lowered by RNA antisense to the resident HPV type. Some of the rat cell lines responded to the antisense plasmids, but some did not. From a nonresponding rat tumor line (3Y1HP‐1T), cell clones with various levels of E7 protein were isolated after transaction with the antisense plasmid, and were examined for anchorageindependent growth in soft agar. The colonies formed by the clones with lower E7 levels tended to be smaller and fewer than those formed by the clones with higher E7 levels. These findings strongly suggest that some of the transformed or cancer phenotypes of cells in vitro are dependent, even after extensive passages and malignant changes, on expression of the oncoproteins of the resident HPV.
Clinical Application of Serum Pepsinogen I and II Levels for Mass Screening to Detect Gastric Cancer
Authors: Miki Kazumasa , Ichinose Masao , Ishikawa Koichi B. , Yahagi Naohisa , Matsushima Masashi , Kakei Nobuyuki , Tsukada Shinko , Kido Masahiro , Ishihama Satoshi , Shimizu Yasuhito , Suzuki Takehisa , Kurokawa Kiyoshi
Published: August 2005

A considerable number of gastric cancers derive from stomach mucosa where chronic atrophic gastritis is severe and extensive. Based on the fact that the serum pepsinogen levels provide a precise measure of the extent of chronic atrophic gastritis, we have devised a mass screening method involving serum pepsinogen measurement to identify subjects at high risk of gastric cancer. In 1991, we screened 4,647 workers (male: 4,113, female: 534, mean age: 49.0 years) at a Japanese company using this method. Out of 875 subjects (18.8%) with a serum pepsinogen I level of less than 50 μg/liter and a pepsinogen I/II ratio of less than 3.0, 676 subjects (14.5%) were selected for further investigation by endoscopy. This led to the detection of four subjects (0.086%) with gastric cancer (three in an early stage) and four subjects with adenoma. The cancer detection rate of this new screening method was comparable, and in some respects superior, to that of the traditional barium X‐ray screening. Since the incidence of test‐positive subjects was as low as 10% amongst subjects aged less than 40, this screening method appears to be especially useful for screening of younger generations. The new method is less expensive than the traditional barium X‐ray and subjects experience little discomfort. Further, many serum samples can be quickly measured simultaneously. The results of this study have indicated that serum pepsinogen screening provides a valuable method for detecting gastric cancers.
A Novel Renal Cell Carcinoma Susceptibility Gene Maps on Chromosome 10 in the Eker Rat
Authors: Hino Okio , Mitani Hiroaki , Nishizawa Masae , Katsuyama Hiroshi , Kobayashi Etsuko , Hirayama Youko
Published: August 2005

Hereditary renal cell carcinoma (RC) in the rat, originally reported by Eker in 1954, is an example of Mendelian dominant predisposition to a specific cancer in an experimental animal. We previously reported that this predisposing inherited gene is a tumor suppressor gene fitting Knudson's “two‐hit” model. This study was designed to map the RC susceptibility gene in the Eker rat using backcross animals. Our present data clearly show that the RC gene is genetically linked to the protamine‐1 gene (Lod score = 11.65) and the interleukin‐3 gene (Lod score=4.13), both of which are located on the proximal part of rat chromosome 10. Rat chromosome 10 is currently believed to have no syntenic relationship to human chromosome 3p, the presumed site of the putative tumor suppressor gene for human RC and the locus of von Hippel Lindau disease (affected patients develop multiple RCs). Thus, the Eker rat might have a mutation of a novel tumor suppressor gene related to renal carcinogenesis.
An Evaluation of Mass Screening Using Fecal Occult Blood Test for Colorectal Cancer in Japan: A Case‐Control Study
Authors: Hiwatashi Nobuo , Morimoto Tomizo , Fukao Akira , Sato Hirofusa , Sugahara Nobuyuki , Hisamichi Shigeru , Toyota Takayoshi
Published: August 2005

There is as yet no firm evidence showing that mass screening for colorectal cancer using fecal occult blood tests (FOBTs) reduces the mortality from this cancer. Therefore we evaluated the effectiveness of the screening by a case‐control study in Miyagi Prefecture, Japan. The study included as case subjects 28 individuals who had died from colorectal cancer and had had an opportunity to participate in the mass screening before the date of diagnosis as colorectal cancer, and 3 controls for each case subject randomly selected from residents who were alive on the date of death of case subjects and matched by sex, age (within 3 years) and living area using residential files. For each set, i.e., a case subject and 3 controls, screening histories before the date of the diagnosis of the case as colorectal cancer were examined. Both the case subjects and the controls who had participated in the screening at least once within 3 years before the date of diagnosis of the case were classified as “screened.” The 28 case subjects consisted of 12 males and 16 females (average age: 60.8 years). The odds ratio of death from colorectal cancer for the screened versus the non‐screened persons was 0.24 (95% confidence interval = 0.08–0.76) by the Mantel‐Haenszel method. The present study suggests that mass screening using FOBTs for colorectal cancer significantly reduces the mortality from this cancer epidemiologically.
Alteration of Radiosensitivity of Quiescent Cell Populations in Solid Tumors Irradiated with X‐Rays Twice at Various Intervals
Authors: Masunaga Shin‐ichiro , Ono Koji , Mitsumori Michihide , Abe Mitsuyuki
Published: August 2005

5‐Bromo‐2′‐deoxyuridine (BUdR) was injected into SCC VII or EMT6/KU tumor‐bearing mice intraperitoneally to label all the proliferating tumor cells. First, the mice were irradiated with X‐rays at a dose of 10 Gy, followed by a dose of 0–20 Gy at 0, 12, 24 or 48 h later. During the interval, no BUdR was injected. Immediately after the second irradiation, the tumors were excised and trypsinized. The micronucleus (MN) frequency in cells without BUdR labeling was determined by means of incubation with cytochalasin‐B (a cytokinesis‐blocker) and immunoftuorescence staining for BUdR. When the tumors were not pretreated with BUdR before the first irradiation, the MN frequency in all tumor cells was determined. To determine the labeling indices of SCC VII and EMT6/KU tumors at the time of the second irradiation, each group also included mice that were continuously administered BUdR until just before the second irradiation using mini‐osmotic pumps which had been implanted subcutaneously 5 days before the first irradiation. The MN frequency of all tumor cell populations obtained immediately after the second irradiation decreased in proportion to the increase in interval time. However, in both tumor systems, the MN frequency of unlabeled cell populations, which could be regarded as quiescent cells in the tumors at the time of the first irradiation, was raised with increase in the interval time. In addition, the labeling index at the second irradiation was higher than that at the first irradiation. These findings support the occurrence of recruitment from quiescent to proliferating state during fractionated irradiation.
Enhancement of Tumorigenicity and Invasion Capacity of Rat Mammary Adenocarcinoma Cells by Epidermal Growth Factor and Transforming Growth Factor‐β
Authors: Li Xiaobin , Nagayasu Hiroki , Hamada Jun‐ichi , Hosokawa Masuo , Takeichi Noritoshi
Published: August 2005

We have studied the effects of growth factors and cytokines on the tumorigenicity and invasion capacity of tumor cells by using regressor and progressor tumor cell lines (ER‐1 and ERpP, respectively) derived from an SHR rat mammary adenocarcinoma. ER‐1 cells regress spontaneously whereas ERpP cells show invasive growth and high metastasis to lung and other organs in syngeneic SHR rats. When ER‐1 cells were pretreated with either epidermal growth factor (EGF) or transforming growth factor‐β (TGF‐β) for 24 h in vitro, and intraperitoneally transplanted into SHR rats, they grew and killed the host, whereas ER‐1 cells pretreated with tumor necrosis factor‐α did not. Tumorigenicity and invasion capacity of ERpP cells were also enhanced by treatment with EGF and TGF‐β. The ER‐1 cells pretreated with EGF, once grown in vivo, had acquired irreversible tumorigenicity and invasion capacity without requiring further EGF treatment, and the enhanced malignancy was irreversible. These findings suggest that growth factors play an important role in acquisition of malignancy of tumor cells.
Analysis of Genetic Alterations Related to the Development and Progression of Breast Carcinoma
Authors: Nagayama Koichi , Watatani Masahiro
Published: August 2005

To study genetic alterations related to the development and/or progression of breast carcinoma, we examined amplification of the ERBB2, INT2, and MYC genes, as well as loss of heterozygosity (LOH) at loci on 11p, 16q, 17p (D17S5 and TP53), 17q (D17S74 and NME1), and 18q by restriction fragment length polymorphism analysis. The subjects were 26 patients with small breast carcinomas (≦2 cm) and 88 patients with larger breast carcinomas (2 to < 5 cm). All patients were free of distant metastasis. As tumor diameter increased, the frequency of oncogene amplification and LOH at all loci except D17S5 increased. However, there was no relationship between tumor diameter and amplification of specific oncogenes or allelic loss at specific loci. LOH at D17S5 was detected in 40% of small breast carcinomas (≦2 cm) and 43% of larger breast carcinomas (2 to < 5 cm). There was a significant correlation of LOH at D17S5 with INT2 amplification or with LOH on 11p, 16q, and 18q. These findings suggest that LOH at D17S5 may be involved in the early stage of breast carcinoma development, while INT2 amplification and LOH at 11p, 16q, and 18q appear to be genetic alterations that occur with tumor progression. In addition, as lymph node metastases were significantly related to amplification of the ERBB2 and MYC genes, and LOH of the NME1 gene, these genetic alterations may play a role in the mechanism of lymph node metastases.
Decreased Dimethylnitrosamine‐induced O6‐ and N7‐Methyldeoxyguanosine Levels Correlate with Development and Progression of Lesions in Rat Hepatocarcinogenesis
Authors: Ozaki Keisuke , Kato Toshio , Asamoto Makoto , Wild Christopher P. , Montesano Ruggero , Nagao Shizuko , Iwase Terubiko , Matsumoto Kazuyuki , Tsuda Hiroyuki
Published: August 2005

Formation and repair of O6‐medG and N7‐medG (O6‐ and N7‐methyldeoxyguanosine) in glutathione S‐transferase‐P form (GST‐P)‐positive liver cell foci, nodules, primary hepatocellular carcinoma (HCC) and transplanted hepatocellular carcinoma (TRP) induced by N‐ethyl‐N‐hydroxyethylnitrosamine (EHEN) were immunohistochemically assessed following a single exposure to dimethyl‐nitrosamine (DMN). Male Fischer 344 rats received a 0.1% solution of EHEN as their drinking water for 4 weeks and were maintained on basal diet until week 40, when a single 50 mg/kg body weight dose of DMN was administered intraperitoneally. Nude rats (NIH rnu/rnu) bearing TRP were similarly treated. Sequential Killing 6, 12, 24, 48 and 72 h thereafter revealed significantly decreased indices of cells binding antibodies to O6‐medG and N7‐medG adducts in GST‐P‐positive foci and nodules, and particularly HCC and TRP, as compared to background parenchyma values. Similarly, differences between foci/nodules and HCC/TRP were also significant, indicating that decrease in adduct formation is associated with further malignant conversion. The rate of DNA adduct repair in foci and nodules subsequent to the peak found at the 12 h time‐point did not appear to be significantly different from that in the surrounding tissue at the dose of DMN studied. The results indicate decreased formation of DMN‐associated DNA damage, in line with the known metabolic profile of carcinogen‐induced focal liver lesions.
Establishment and Characterization of a Rat Yolk Sac Tumor Cell Line, NMT‐1, Producing α‐Fetoprotein, with Potential for Lymphatic Metastasis
Authors: Mitsuhashi Norio , Takahashi Takeo , Nozaki Miwako , Matsumoto Hiroko , Sakurai Hideyuki , Takahashi Mitsuhiro , Niibe Hideo
Published: August 2005

A new cell line producing α‐fctoprotein, designated NMT‐1, was established from rat yolk sac tumor with the potential for lymphatic metastasis in inbred Wistar rats. In this paper, we investigated the characteristics of NMT‐1 cells. The cell line grew in a monolayer and had a polygonal epithelioid appearance in phase‐contrast microscopy. The doubling time of NMT‐1 cells during exponential growth was approximately 16 h in RPMI‐1640 with 10% fetal calf serum. The D0 value for radiation sensitivity was 97 ±3 cGy. The extrapolation number, n, for NMT‐1 was 1.08 ± 0.15, In the log phase, the G0/G1, S and G2/M fractions were 23.2%, 62.1% and 14.3%, respectively. Tumor take was observed in all of the rats inoculated with NMT‐1 cells. In the case of flank tumor, the mean survival time was 104 days after inoculation with 106 tumor cells. Inguinal, axillar, paraaortic, mesenteric and mediastinal lymphnode metastases were observed in all rats inoculated with NMT‐1 cells. Rats which survived for a long time developed metastases in a lymphatic vessels of the liver, lung and/or kidney microscopically. The biological behavior and the histopathological features of the tumor induced by inoculation with NMT‐1 cells were the same as those of the original tumor induced by fetectomy.
Telomere Change and Loss of Heterozygosity of Mouse Primary Tumors and Cell Lines
Authors: Hayashi Tatsuhiko , Mafune Yoshiro , Takada Toshinori , Hatakeyama Katsuyoshi , Takagi Nobuo , Kominami Ryo
Published: August 2005

Changes in the number of telomere repeat arrays were examined in mouse tumor cells. Telomeres that function for the protection of chromosomes were detected as bands and a smear by pulsed field gel electrophoresis and gel‐hybridization using (TTAGGG)4, as a probe. Of eight primary tumors induced in F1 mice between C57BL/6 and C3H/He and between C57BL/6 and MSM, three showed telomere alteration, two having extra bands and one having lost several telomere bands. The others exhibited patterns similar to those of normal tissues. However, the change was detected in all four cell lines that were established from one of the tumors. One cell line was further cloned and examined. Two of the nine clones differed in the telomere pattern. The telomere change was also observed in two other cell lines, FM3A cells and nontransformed BALB3T3 cells. These results suggest that telomeres are highly mutable in tumor cells and cultured cell lines. Three of the tumors and one cell line were analyzed for loss of heterozygosity with 51 microsatellite probes covering all 19 autosomes. Also, karyotype analysis of the cell line was performed. No allelic loss was seen and chromosomal abnormality was rare, although aneupoloidy and imbalance in chromosomal number were observed. Possible involvement of the telomere changes observed here in chromosome impairment is discussed.
Functional Analysis of Mononuclear Cells Infiltrating into Tumors: Establishment of T Cell Hybridomas Exhibiting Distinct Interacting Abilities with Endothelial Cells and Extracellular Matrix Components
Authors: Uno Eiji , Kikuchi Kokichi , Saiki Ikuo , Uede Toshimitsu
Published: August 2005

We have established eleven T cell hybridoma cell lines to investigate mechanisms controlling interaction of T lymphocytes with endothelial cells as well as extracellular matrix (ECM) proteins at the clonal level. T cell hybridomas were characterized and subdivided Into four groups on the basis of their interaction behavior with high endothelial venules (HEV). Group 1 (G1) exhibited strong adhesiveness. The binding was temperature‐ and divalent cation‐dependent. Group 2 exhibited both adhesiveness and transendothelial migration (TEM, i.e., transmigration beneath the cytoplasm of endothelial cells). Group 3 exhibited strong TEM. G2 and G3 hybridomas exhibited temperature‐independent and divalent cation‐independent binding to HEV. Group 4 exhibited nonspecific adhesiveness to the surface of a slide glass. BW 5147, a parent of T cell hybridomas, was classified as G4. TEM was dependent on both the nature of T cell hybridomas and endothelial cells. TEM was completely temperature‐dependent. TEM of G3 hybridomas was not divalent cation‐dependent. Each group of T cell hybridomas interacted with various ECM components.
Neutralizing Antibody to Vesicular Stomatitis Virus (HTLV‐I) Pseudotype in Infants Born to Seropositive Mothers
Authors: Iwahara Yoshihito , Sawada Takashi , Taguchi Hirokuni , Hoshino Hiroo , Umemoto Masakazu , Take Hiromichi , Foung Steven , Miyoshi Isao
Published: August 2005

Breast feeding is the major route of mother‐to‐child transmission of human T‐cell leukemia virus type I (HTLV‐I). Our experiments with rabbits have shown that passive immunization is capable of blocking ceil‐to‐cell infection of HTLV‐I by blood transfusion or breast feeding. In this study, sera were collected serially from 3 infants born to seropositive mothers and were tested for the presence of neutralizing antibody to vesicular stomatitis virus (HTLV‐I) pseudotype as well as antibodies to viral structural proteins. There was a good correlation between neutralizing and viral antibody titers, both of which were detectable until 3–6 months after birth. Whether maternally transmitted neutralizing antibody is protective against perinatal infection of HTLV‐I remains to be studied.
Enhanced Antitumor Efficacy of a Combination of CPT‐11, a New Derivative of Camptothecin, and Cisplatin against Human Lung Tumor Xenografts
Authors: Kudoh Shinzoh , Takada Minoru , Masuda Noriyuki , Nakagawa Kazuhiko , Itoh Kazunobu , Kusunoki Yohko , Negoro Shun‐ichi , Matsui Kaoru , Takifuji Nobuhide , Morino Hideo , Fukuoka Masahiro
Published: August 2005

The objective of this study was to evaluate the antitumor efficacy of combined use of 7‐ethyl‐10‐[4‐(1‐piperidino)‐1‐piperidino]carhonyloxycamptothecin (CPT‐11) and cisplatin (CDDP). The antitumor activities of CPT‐11, CDDP and their combination against 3 human lung tumor xenografts were estimated using congenitally athymic BALB/c (nu/nu) mice. The doses were 47 mg/kg for CPT‐11 and 6 mg/kg for CDDP on days 1, 5 and 9. In combination therapy, half of the single dosage of each agent was used. The doses were administered intraperitoneally. The antitumor activity and toxicity were evaluated in terms of the tumor volume and body weight change of mice, respectively. The combination therapy resulted in a statistically significant tumor regression compared to the use of only CPT‐11 or CDDP in two tumor xenografts out of three. The toxicity of the combination therapy was no higher than that of CPT‐11 or CDDP alone. These results suggest that the antitumor activity of the combination of CPT‐11 and CDDP is superior to that of CPT‐11 or CDDP alone.