bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluctuations in Tumor Blood Flow under Normotension and the Effect of Angiotensin II‐induced Hypertension
Authors: Hori Katsuyoshi , Suzuki Maroh , Tanda Shigeru , Saito Sachiko , Shinozaki Mika , Zhang Qiu‐Hang
Published: August 2005

To elucidate the significance of angiotensin II (AID‐induced hypertension chemotherapy, changes of tissue blood flow both in normal subcutis and in tumors (AH109A, LY80) were measured with the hydrogen gas clearance method. A newly‐developed anesthetic machine was used to keep the animals' condition constant. Tissue blood flow in normal subcutis and tumors always fluctuated with time under normotension. The nature and the rate of fluctuation in tumor Wood flow were almost identical in two different types of tumors. However, the fluctuation of blood flow in tumor and that in normal subcutis were almost always inversely related when blood flows in these different tissues were measured simultaneously, i.e., when tissue blood flow in normal subcutis decreased, tumor blood flow increased, and vice versa. The findings supported the idea that the connection mode between the tumor vascular bed and normal vascular bed is a parallel circuit. Vascular resistance in the normal vascular bed under All‐induced hypertension seemed to be greater than that under normotension, because the All‐increased tumor blood flow always exceeded the maximum tumor blood flow under normotension. Due to the fluctuations of tumor blood flow, no‐flow or low‐flow areas, resistant to delivery of anti‐cancer drugs, moved sporadically within the tumor under the normotensive condition. However, good conditions for drug delivery to tumor tissue were induced by All‐induced hypertension.
Tumorigenic Transformation of Primary Rat Embryonal Fibroblasts by Human Papillomavirus Type 8 E7 Gene in Collaboration with the Activated H‐ras Gene
Authors: Nishikawa Takeshi , Yamashita Toshiharu , Yamada Takashi , Kobayashi Hitoshi , Ohkawara Akira , Kei Kei
Published: August 2005

Particular types of human papillomavirus (HPV) are associated with skin cancer of epidermo‐dysplasia verruciformis (EV) patients. Here, we show, for the first time, that the E7 gene of EV‐associated HPV8 possesses a potential oncogenic transforming ability. The HPV8 E7 open reading frame (ORF) and the HPV16 E7 ORF were cloned under the SV40 promoter/enhancer to construct recombinant plasmids pcD2‐8E7 and pcD2‐16E7, respectively. Transfection of primary rat embryonal flbroblasts having an activated H‐ras gene revealed that pcD2‐8E7 as well as pcD2‐16E7 induced transformation of cells In G418‐resistant colonies at an efficiency of 12.3% and 42.9%, respectively. The resulting transformed cell lines induced by pcD2‐8E7 and activated H‐ras were tumorigenic when injected into syngeneic immunocompetent rats. The potential tumorigenicity of HPV8 E7 seemed to be higher than that of HPV16 E7.
Flow Cytometric Measurements of Somatic Cell Mutations in Thorotrast Patients
Authors: Umeki Shigeko , Kyoizumi Seishi , Kusunoki Yoichiro , Nakamura Nori , Sasaki Masao , Mori Takesaburo , Ishikawa Yuichi , Cologne John B. , Mitoshi Mitoshi
Published: August 2005

Exposure to ionizing radiation has long been well‐recognized as a risk factor for cancer development. Since ionizing radiation can induce mutations, an accurate way of measuring somatic mutation frequencies could be a useful tool for evaluating cancer risks. In the present study, we have examined in vivo somatic mutation frequencies at the erythrocyte glycophorin A (GPA) and T‐cell receptor (TCR) loci in 18 Thorotrast patients who have been continuously irradiated with alpha‐particles emitted from the internal deposition of thorium dioxide and who thus have increased risks of certain malignant tumors. When compared with controls, the results showed a significantly higher frequency of mutants at the lymphocyte TCR loci but not at the erythrocyte GPA loci in the Thorotrast patients. The discrepancy between the results of the two assays is discussed.
Second Primary Cancers Following Colon and Rectal Cancer in Osaka, Japan
Authors: Tanaka Hideo , Hiyama Tomohiko , Hanai Aya , Isaburo Isaburo
Published: August 2005

The frequencies of second primary cancers following colon and rectal cancers were estimated using the Osaka Cancer Registry's population‐based data for Osaka, Japan. A series of 7,312 colon and 6,923 rectal cancer cases newly diagnosed in the period of 1966‐1986 were followed up until the end of 1986. The average follow‐up period was 3.6 years for colon cancer and 3.7 years for rectal cancer. Significantly elevated risks of second primary cancers following colon cancer were observed for cancers of the rectum (O/E= 2.0; 95% confidence interval (CI) = 1.1‐3.4 among males, O/E=4.3; 95% CI=2.4‐7.2 among females), corpus uteri (O/E=8.2; 95% CI = 3.3‐16.9), ovary (O/E=4.3; 95% CI = 1.0‐5.0), and female thyroid gland (O/E=4.7; 95% CI=1.7‐8.8). These findings were more notable among right‐sided colon cancer patients than left‐sided colon cancer patients. The elevated risks of second primary cancers were particularly evident among patients younger than 50 years of age at the time of diagnosis of the initial cancer (colon cancer: O/E = 3.1 among males, 3.4 among females, rectal cancer: O/E=1.7 among males, 1.3 among females). These findings suggest that younger colorectal cancer patients should undergo more careful checkups throughout their lives.
Rapid Induction of Endometrial Carcinoma in ICR Mice Treated with N‐Methyl‐N‐nitrosourea and 17β‐Estradiol
Authors: Niwa Kenji , Tanaka Takuji , Mori Hideki , Yokoyama Yasuhiro , Furui Tatsuro , Mori Hidehiro , Teruhiko Teruhiko
Published: August 2005

The present study was undertaken to develop an animal model for endometrial neoplasms. A total of 107 female ICR mice, 10 weeks of age, were used and treated as follows: Group 1 (31 mice) was given intravaginal instillation of N‐methyl‐N‐nitrosourea (MNU) solution (1 mg/100 g body wt.) once a week for three weeks and then fed diet containing 5 ppm 17/β‐estradiol (E2) for 20 weeks, starting one week after the last exposure to MNU, Group 2 (30 mice) was given MNU alone. Group 3 (31 mice) was given E2 diet alone. Group 4 (15 mice) was fed the basal diet alone and served as the untreated control. At the termination of the experiment (week 23), all surviving mice were killed. Histopathological examination revealed that adenocarcinomas in the uterine corpus developed in mice of Groups 1‐3, with a high incidence of endometrial hyperplasia. The incidence of endometrial carcinomas in Group 1 (15/31, 48%) was significantly higher than in Group 2 (2/29, 7%, P < 0.001) or Group 3 (7/31, 23%, P > 0.01). In the uterine cervix, small numbers of squamous cell carcinomas and pre‐neoplastic lesions (dysplasias and hyperplasias) were also present in mice of Groups 13. In Groups 1 and 3, an increased E2/progesterone (P) ratio was observed. Thus, the results indicated that this medium‐term model for endometrial neoplasms is useful for studying the pathogenesis of endometrial cancer and that an increased E2/P ratio is an important factor for the development of endometrial adenocarcinoma.
Detection of Human Antibody against the Human Papillomavirus Type 16 E7 Protein
Authors: Hashido Madoka , Kanda Tadahito , Zanma Soichi , Watanabe Sumie , Komiyama Naoki , Yoshikawa Hiroyuki , Yamaguchi Nobuo , Kawana Takashi , Kunito Kunito
Published: August 2005

We examined 500 human sera for the presence of antibody against the human papillomavirus type 16 E7 protein by enzyme‐linked immunosorbent assay with bacterially expressed fusion protein lac‐E7, and by radioimmunoprecipitation and immunofluorescence assays with the E7 protein expressed in monkey COS‐1 cells. The anti‐E7 antibody was detectable in 6 out of 54 cases of cervical carcinoma, but in none of the others, including patients with other gynecologic cancers, those with sexually transmitted diseases, and healthy adults. The data indicate that expression of the E7 protein is closely related to cervical carcinoma.
Tissue Distribution of Mouse Mammary Tumor Virus (MMTV) Antigens and Endogenous MMTV Loci in Japanese Laboratory Mouse Strains
Authors: Wajjwalku Worawidh , Takahashi Masahide , Miyaishi Osamu , Lu Jin , Sakata Keita , Yokoi Toyoharu , Saga Shinsuke , Imai Masao , Matsuyama Mutsushi , Hoshino Munemitsu
Published: August 2005

The distribution of mouse mammary tumor virus (MMTV) antigens was studied by the immunoper‐oxidase method in the II‐TES and I‐TES mouse strains as well as their progenitors, CS and DBA/2 strains. In the II‐TES, I‐TES and CS strains, and BALB/c mice foster‐nursed with these strains, MMTV antigens were found not only in epithelial cells of the mammary glands but also in those of other tissues including the seminal vesicle, vas deferens, epididymis, prostate, parotid, submandibular, lacrimal, sebaceous, and urethral glands. In DBA/2 and BALB/cfDBA/2 mice, however, the MMTV antigens were found only in the mammary glands. Electron microscopic examination showed MMTV particles in these organs. When we examined the presence of Mtv‐1 and 2 proviruses, which are known to be responsible for MMTV expression, in the genomes of the II‐TES, I‐TES, CS and DBA/2 strains by Southern blotting, Mtv‐2 was not found in any of the mice and Mtv‐1 was found in the II‐TES and DBA/2 mice but not in the I‐TES and CS mice. Instead, four new endogenous MMTV loci, which have never previously been reported in laboratory mouse strains, were detected in the genomes of the II‐TES, I‐TES and CS strains. One (designated Mtv‐42) was common in the three strains and the other three (designated Mtv‐43, 44 and 45) were common in the II‐TES and I‐TES strains or the II‐TES and CS strains. These results thus suggest that new endogenous MMTV loci may be responsible for MMTV expression in a variety of tissues of these three strains.
Aberrant Elevation of Tyrosine‐specific Phosphorylation in Human Gastric Cancer Cells
Authors: Takeshima Eisuke , Hamaguchi Michinari , Watanabe Tadashi , Akiyama Seiji , Kataoka Masato , Ohnishi Yukano , Xiao Hengyi , Nagai Yoshiyuki , Hiroshi Hiroshi
Published: August 2005

Phosphotyrosine‐containing proteins in various human cancer cell lines were studied by immunoblotting with anti‐phosphotyrosine antibody. Of 29 cell lines derived from oral epidermoid cancer, esophageal cancer, gastric cancer, colon cancer, pancreatic cancer, hepatocellular carcinoma and malignant melanoma, 3 of the 6 gastric cancer cells showed aberrant elevation of tyrosine‐speciflc phosphorylation. On the other hand, both esophageal cancer cells and colon cancer cells, which were reported to have amplified epidermal growth factor receptor and activated p60v‐src kinase, respectively, showed no apparent elevation of tyrosine‐specific phosphorylation, and their profiles of phosphorylation were similar to that of normal human fibroblasts. Two gastric cancer cells, NUGC‐4 and MKN‐45, showed similar profiles of phosphorylation but their responses to growth factors differed from each other. Tyrosine phosphorylation in NUGC‐4 was strongly activated by treatment with epidermal growth factor and quickly reduced by the acid treatment which is effective in removing growth factors from cellular surface receptors. On the contrary, phosphorylation in MKN‐45 did not respond to either growth factor or acid treatment. These results suggest that NUGC‐4 and MKN‐45 have tyrosine kinases which are activated by different mechanisms but share similar substrates.
Cytochrome P‐450 Isozyme Pattern Is Related to Individual Susceptibility to Diethylnitrosamine‐induced Liver Cancer in Rats
Authors: Aitio Antero , Aitio Mirja‐Liisa , Camus Anne‐Marie , Cardis Elisabeth , Bartsch Helmut
Published: August 2005

Differences in susceptibility to chemical carcinogenesis between rodent strains and species have been linked to variations in genetically‐determined mixed function oxidase activities. In order to verify whether such variations also determine the susceptibility of individual animals of the same strain to a chemical carcinogen, outbred male Wistar rats were administered diethylnitrosamine (DEN) (1, 2, or 3 nig/kg) five times a week for 20 weeks. The relationship was examined between the outcome (i.e. presence or absence of liver tumors, and latency period) and the hepatic activities of mixed function oxidases and conjugating enzymes, as well as of O6‐methylguanine‐DNA‐methyltransferase, measured before the carcinogen treatment. In addition, the metabolic profiles of two model drugs, antipyrine and disopyramide, in the urine were analyzed and correlated with the carcinogen susceptibility. The length of the latency period of hepatocellular tumors in individual rats was negatively related to the activities of hepatic dimethylnitrosamine N‐demethylase, aryl hydrocarbon hydroxylase and epoxide hydrolase and positively related to the amount of microsomal protein. Consistent relationships between the other 10 measured parameters and the susceptibility to DEN‐induced carcinogenesis were not detected. Long‐term treatment with DEN slightly decreased the proportion of metabolism of antipyrine into norantipyrine, and increased the share of 4‐hydroxyantipyrine; a decrease in the metabolism of disopyramide to N‐deisopropyldisopyramide was also detected. It is concluded that the pattern of cytochrome P‐450 isoenzymes is related to differences in individual susceptibility to nitrosamineinduced carcinogenesis. The relationship was most marked at low dose levels, which are the levels at which nitrosamine exposures of humans are known to occur.
Platelet Aggregation Induced by Adenosine Diphosphate Released from Cloned Murine Fibrosarcoma Cells Is Positively Correlated with the Experimental Metastatic Potential of the Cells
Authors: Mogi Yoshihiro , Kogawa Katsuhisa , Takayama Tetsuji , Yoshizaki Naohito , Bannai Kiyoshi , Muramatsu Hirohito , Koike Kazuhiko , Kohgo Yutaka , Watanabe Naoki , Niitsu Yoshiro
Published: August 2005

We established five clones (ML‐01, ML‐02, MH‐01, MH‐02, MH‐03) from murine 3‐methylcholan‐threne‐induced fibrosarcoma A (Meth A), and investigated their experimental metastatic potentials in relation to their platelet‐aggregating activities. A clone with a high metastatic potential (MH‐02) showed a characteristic biphasic pattern of platelet aggregation, of which the first peak was not present in the aggregation patterns of the clone with low metastatic potential (ML‐01). The first peak was eliminated by treatment of the cells with apyrase, indicating that adenosine diphosphate (ADD was the causative substance of this particular peak. The metastatic potential of clones correlated well with the ADP concentration of the culture media. These results suggest that the increased ADP production and consequential enhancement of platelet‐aggregating activity are closely related to the increment of pulmonary metastatic potential of MH‐02 clone.
Release of Esterase from Murine Lymphokine‐activated Killer Cells in Antibody‐dependent Cellular Cytotoxic Reaction
Authors: Kato Kazunori , Agatsuma Toshinori , Tanabe Toshifumi , Masuko Takashi , Hashimoto Yoshiyuki
Published: August 2005

Release of granule enzyme(s) (BLT esterase) in the antibody dependent lymphokine‐activated killer (LAK) cell‐mediated cytotoxic reaction (LAK ADCC) was studied using LAK cells induced from murine splenocytes and thymocytes, various human tumor cells and relevant monoclonal antibodies (mAbs) to the tumor cells. BLT esterase was not significantly released from LAK cells in direct LAK cell‐mediated cytotoxic reactions (LAK CMC). However, cultures of LAK cells and IgG‐coated target tumor cells resulted in release of the enzyme concomitantly with target cell lysis, although esterase release proceeded faster than target cell lysis. Anti‐LFA‐1 mAb showed an inhibitory effect on LAK CMC but not on either LAK ADCC or BLT esterase release in the ADCC. These results indicate that exocytosis of granule enzyme from LAK cells is triggered by stimulation of Fc receptor on LAK cells and that LAK CMC and LAK ADCC differ in their lytic mechanism in terms of the release of BLT esterase.
Induction of Intestinal Adenocarcinomas by 2‐Amino‐l‐methyl‐6‐phenylimidazo‐[4,5‐b] pyridine in Nagase Analbuminemic Rats
Authors: Ochiai Masako , Ogawa Kumiko , Wakabayashi Keiji , Sugimura Takashi , Nagase Sumi , Esumi Hiroyasu , Nagao Minako
Published: August 2005

2‐Amino‐l‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), the most abundant mutagenic heterocyclic amine in cooked foods, was examined for carcinogenic potential using Nagase analbuminemic rats (NARs), which are sensitive to various carcinogens. The concentration of PhIP in the diet was 0.04% at the beginning of the experiment, this being subsequently gradually reduced to 0.01% to avoid severe body weight loss. Ten of 13 treated NARs developed a total of 36 intestinal tumors within the 311‐day experimental period. Among these, 22 were adenocarcinomas and 2 were adenomas of the small intestine, 4 were adenocarcinomas of the cecum and 8 were adenocarcinomas of the large intestine. The results suggest that PhIP could represent a significant risk to human populations exposed to foods containing heterocyclic amines.
Improvement of Gelatin Particle Agglutination Test for Detection of Anti‐HTLV‐I Antibody
Authors: Fujino Ryuichi , Kawato Katsuhito , Ikeda Mikio , Miyakoshi Hideo , Mizukoshi Mikio , Imai Joko
Published: August 2005

Partial modifications of antigen components were made to improve the gelatin particle agglutination (PA) test for the detection of antibodies against human T cell leukemia virus type‐I. Envelope glycoproteins prepared by lentil lectin affinity chromatography were further added to the purified viral antigens to be coated on the gelatin particles. Comparative studies with a conventional PA test kit (Serodia ATLA) and indirect immunofluorescence assay showed that the specificity and sensitivity of the new PA test were increased and that abnormal agglutination such as the prozone phenomenon was abolished by this improvement.
Chromosomal Insertion and Amplification of Human Papillomavirus 16 DNA Sequences in a Cell Line of Argyrophil Small Cell Carcinoma of the Uterine Cervix
Authors: Hori Tada‐aki , Ichimura Hiroshi , Minamihisamatsu Masako , Takahashi Ei‐ichi , Yamauchi Masatake , Hama Yuko , Kurimura Osamu , Yamasaki Masato , Kurimura Takashi
Published: August 2005

The chromosomal location of human papillomavirus (HPV) 16 DNA sequences integrated in a cell line derived from argyrophil small cell carcinoma of the uterine cervix was determined by means of fluorescence in situ hybridization (FISH). The HPV 16 DNA sequences were integrated near a fragile site and the location of the c‐myc oncogene at 8q24.1. Amplification of the integrated viral sequences resulted in an abnormally banded region. The amplified HPV 16 DNA sequences were also detected in every interphase nucleus by FISH.
Appearance of a Carcinoid–like Pattern in Rat Hepatic Tumors Induced by 3′–Methyl‐4–dimethyl ‐aminoazobenzene
Authors: Karaki Yoshiaki , Munakata Shuji , Saeki Toshio , Hirota Sanae , Fujimaki Masao
Published: August 2005

This study investigated the histological distribution of argyrophilic cells in experimental hepatic neoplasms, the number of these cells, and the proportion of neoplasms with such cells. Seventy 6–week–old male Donryu rats were given a 0.06% 3′–methyl–4–dimethyl–aminoazobenzene (3′–MeDAB) diet for 10 weeks, followed by an ordinary diet for an additional 10 weeks. Of the 70 rats, 50 were used for this investigation; 29 had hepatic tumors, 18 had cholangiofibrosis, and the other three had oval cell proliferation only. Hepatic tissues were stained with Grimelius and Fontana–Masson stains as well as routine hematoxylin–eosin stain. Argyrophilic cells were found in the hepatic neoplasms of 8 rats without argentaffin cells, while cholangiofibrosis was associated with argentaffin cells in almost all cases. Of the 8 rats with argyrophilic cells, three had an abundant population of these cells. The argyrophilic cells were found in areas of the neoplasms with a glandular, trabecular, tubular, or poorly differentiated pattern. Electron microscopy revealed that the neoplastic cells with a positive argyro–phil reaction contained small round electron–dense endocrine granules. In addition, in the areas of cholangiofibrosis, two different types of gut endocrine cells were present (G and EC cells). These results suggest that 3′–MeDAB might induce hepatic carcinoid under certain conditions, though we have yet to confirm the development of a pure hepatic carcinoid due to this substance.
Quantitative Assay of Epidermal Growth Factor Receptor in Human Squamous Cell Carcinomas of the Oral Region by an Avidin‐Biotin Method
Authors: Kawamoto Tomoyuki , Takahashi Kojiro , Nishi Mieko , Kimura Takuji , Matsumura Tomohiro , Taniguchi Shigehiko
Published: August 2005

A quantitative assay method for epidermal growth factor receptors (EGFRs) of human tumor tissues was established, based on enzyme‐labeled avidin‐biotin (LAB) interaction with anti‐human EGFR monoclonal antibody 52SIgG. A standard calibration curve for EGFR estimation in human tumor tissues was obtained with A431#8 cells cloned from A431 human epidermoid carcinoma cell line. The coefficient of variance for the standard curve was below 35% in the application to tumor tissues from nude mice implanted with human tumor cell lines. The minimum tissue amount required for the quantitative assay was around 0.1 g (wet weight). Using the LAB method, the correlation between the level of EGFR number and tumor malignancy was examined for 14 human squamous cell carcinomas (SCCs) from the oral region. Seven of the SCCs showed a more than two‐fold higher EGFR number compared to normal gingival tissues. Three highly aggressive carcinomas with poor prognosis possessed five to ten times higher levels of EGFR number than normal tissues. The elevated EGFR level in the SCCs seems to correlate to increasing tumor size and the stage of SCCs as clinically classified according to the 1987 UICC TNM system.
Establishment of Mouse Lymphokine‐activated Killer Cell Clones and Their Properties
Authors: Kato Kazunori , Sato Naoko , Tanabe Toshifumi , Yagita Hideo , Agatsutna Toshinori , Hashimoto Yoshiyuki
Published: August 2005

To assess the properties of lymphokine‐activated killer (LAK) cells, we established mouse LAK cell clones from LAK cell lines induced from C57BL/6 mouse spleen cells. Although these clones expressed similar phenotypes to the parent LAK cells, Lyt‐2 was expressed in a restricted portion of the clones. All clones were found to express T3 CD3 and T cell receptor (TcR) αβ on their cell surface. Rearrangement patterns of TcR were the same among the clones derived from the same parent cell line but differed in those from different cell lines as determined by using Cβ1 and Jβ probes. The molecules responsible for LAK‐target cell binding were examined by using a monoclonal antibody (mAb) against lymphocyte function associated antigen 1 (LFA‐1). This mAb (termed KBA) showed inhibitory effects on both LAK‐target cell binding and cytolytic activity of LAK cell clones, indicating a principal role of LFA‐1 in LAK cell clones. The magnitude of perform mRNA expression in LAK cell clones was unrelated to their cytolytic activities.
Augmentation by Tumor Necrosis Factor α of the Systemic Therapeutic Effect of Lymphokine‐activated Killer Cells in Adoptive Immunotherapy of Murine Tumor
Authors: Kato Kazunori , Tanabe Toshifumi , Agatsuma Toshinori , Suzuki Shinya , Nitanai Hironobu , Hashimoto Yoshiyuki
Published: August 2005

The therapeutic effect of a combined modality of lymphokine‐activated killer (LAK) cells and tumor necrosis factor α (TNFα) on MBL‐2 tumor in C57BL/6 mice was studied. Murine LAK cells induced from splenocytes by interleukin 2 (IL2) could lyse MBL‐2 target cells in vitro, but no enhancement of the LAK activity was found by the treatment of LAK cells with TNFαin vitro. However, the treatment of MBL‐2 with TNFα enhanced the sensitivity to LAK cells. Moreover, administration of TNFα to mice bearing solid MBL‐2 tumor led to increased tumor vascular permeability within 1 h, and resulted in the enhanced accumulation of systemically transferred LAK cells in tumor tissue. Based on these results, we treated MBL‐2‐bearing mice with TNFα and then with LAK cells 1 h later, No therapeutic effect was observed when tumor‐bearing mice were treated with TNFα alone or LAK cells plus IL2. However, adoptive immunotherapy using LAK cells and TNFα had therapeutic effects, i.e. growth inhibition of tumor nodules and prolongation of survival. These results indicated that appropriately timed pretreatment of tumor‐bearing mice with TNFα augmented the anti‐tumor efficacy of LAK cells.
The Effect of Interferon on Carcinogenesis by N‐Ethyl‐N'‐nitro‐N‐nitrosoguanidine in the Duodenum of Mice
Authors: Yamane Tetsuro , Fujita Yoshihiro , Sagara Yukihiko , Takahashi Toshio , Imanishi Jiro
Published: August 2005

The inhibitory effect of murine interferon α/β (Mu‐IFN) on the induction of adenocarcinoma of the duodenum in C57BL/6 mice given N‐ethyl‐N‐nitro‐N‐nitrosoguanidine (ENNG) was examined. ENNG was given continuously in drinking water for 4 weeks and Mu‐IFN was given intraperitoneally for 12 weeks. Then, the duodenal tumors of mice were examined stereomicroscopically and histologically. The level of IFN activity and natural killer (NK) activity were evaluated after an intraperitoneal single injection of Mu‐IFN, and the level of NK activity was evaluated 2, 5 and 8 weeks after giving ENNG and Mu‐IFN. In the mice given Mu‐IFN, the incidence of duodenal tumors was significantly decreased (P < 0.01), compared with that in mice given ENNG alone. Further, anti‐asialo GM1 was given intraperitoneally every 5 days for 8 weeks to depress NK function and the incidence and size of duodenal tumors were examined. The results indicated that NK cells also have an important effect on the process of carcinogenesis. These data suggest that chemoprevention with IFN may be feasible.
Antitumor Activity of Fluoropyrimidines and Thymidylate Synthetase Inhibition
Authors: Kubota Tetsuro , Fujita Shin , Kodaira Susumu , Yamamoto Takaaki , Josui Kazuya , Arisawa Yoshito , Suto Akihiko , Ishibiki Kyuya , Abe Osahiko , Mabuchi Kazunori , Fuse Makoto
Published: August 2005

Experimental chemotherapy with 5‐fluorouracil (5‐FU; 60 mg/kg), l‐hexylcarbamoyl‐5‐fluorouracil (HCFU; 70 mg/kg), 3‐(3‐(6‐benzoyloxy‐3‐cyano‐2‐pyridyloxycarbonyI)benzoyl)‐l‐ethoxymethyl‐5‐fluorouracil (BOF‐A2; 30 mg/kg) and UFT (20 mg/kg as tegafur with uracil at a molar ratio of 1:4) was performed using human gastric (H‐111) and colon (Co‐4) carcinoma strains in nude mice. 5‐FU was administered ip with a q4d × 3 schedule and the other agents were given po daily for three weeks. Concentrations of 5‐FU in the serum and the tumor were assessed by gas chromatography‐ntass fragmentography, two hours or 12 days (5‐FU) after the last treatment, and thymidy late synthetase (TS) was assayed according to the method of Spears et al. using the same schedule. The antitumor activity of the agents was assessed in terms of the actual tumor weight at the end of the experiment. HCFU was effective against both strains and 5‐FU was effective against Co‐4, although the other agents were ineffective against either strain. Statistically significant correlations were found between the serum and tumor concentrations of 5‐FU and antitumor activity. Statistically significant correlations were also observed between the antitumor activity and TS inhibition rate (TSIR) and the activity of free thymidylate synthetase (TSfree), with higher TSIR and lower TSfree resulting in higher antitumor activity. Therefore, TSIR and TSfree were thought to be promising indicators for predicting the antitumor activity of fluoropyrimidines.
Serum Requirement for in vitro Invasion by Tumor Cells
Authors: Imamura Fumio , Horai Takeshi , Mukai Mutsuko , Shinkai Kiyoko , Akedo Hitoshi
Published: August 2005

The effect of fetal calf serum (FCS) on in vitro invasion by rat ascites hepatoma cells (AH130) was studied by using the in vitro invasion assay. Although the coculture of the highly invasive clone (MM1) of AH130 cells and the mesothelial cell layer or endothelial cell layer in modified minimum essential medium supplemented with 10% PCS resulted in extensive penetration of the layer by the tumor cells, the omission of PCS resulted in an almost complete elimination of the in vitro invasion. The in vitro invasiveness by human small cell lung cancer cells (OCIO) was also remarkably reduced by the omission of PCS from the assay medium, suggesting a requirement of serum for the in vitro tumor cell invasion. When 10% PCS was added to the medium 2 h after the tumor cell seeding in FCS‐free invasion assay system, penetration by MM1 cells was observed within an hour. This rate of penetration was almost the same as that when 10% PCS was added at the time of tumor cell seeding. PCS was also required for the penetration of a mesothelial cell monolayer by MM1 cells in a defined growth medium (SFM‐101), in which MM1 cells were well maintained. The invasion‐inducing activity appears to be independent of the growth‐stimulating activity in serum.
Induction of Transplantable Tumors by Repeated Subcutaneous Injections of Natural and Synthetic Vitamin E in Mice and Rats
Authors: Nitta Yumiko , Kamiya Kenji , Tanimoto Masanori , Sadamoto Seiji , Niwa Ohtsura , Yokoro Kenjiro
Published: August 2005

Natural vitamin E and synthetic vitamin E (dl/‐α‐tocopheryl acetate) were tested for their tnmorigenicity in rodents. Transplantable tumors, at the site of injection, were induced by repeated injections of these compounds in two strains of mice, NFS/N and C57BL/6N × C3H/He Fl, and in a strain of rats, Fischer 344. Natural vitamin E was tumorigenic in both strains of female mice only when injected with soya oil. In contrast, dl‐α‐tocopheryl acetate alone was capable of inducing tumors in Fischer 344 rats. Only one out of 5 male NFS/N mice given dl‐α‐tocopheryl acetate developed a tumor. Therefore, Fischer 344 rats were more susceptible to tumor formation by dl‐α‐tocopheryl acetate than NFS/N mice. dl‐α‐Tocopheryl acetate with soya oil or with palm oil also resulted in the formation of transplantable tumors in NFS/N mice and Fischer 344 rats. There was no difference in the tumor incidence between mice treated with dl‐α‐a‐tocopheryl acetate alone and dl‐α‐tocopheryl acetate plus soya oil or palm oil. However, in rats, the incidence was lower for a group treated with dl‐α‐tocopheryl acetate plus palm oil than for those with dl‐αa‐tocopheryl acetate alone and with dl‐α‐tocopheryl acetate plus soya oil.
Multipotent and Committed CD34+ Cells in Bone Marrow Transplantation
Authors: Ema Hideo , Suda Toshio , Nakauchi Hiromitsu , Nakamura Yukio , Iwama Atsushi , Imagawa Shigehiko , Akutsu Miyuki , Kano Yasuhiko , Kato Shunichi , Yabe Miharu , Yoshida Minoru , Sakamoto Shinobu , Amemiya Youichi , Miura Yasusada
Published: August 2005

In order to study the role of CD34+ cells in hematological recovery following bone marrow transplantation (BMT), bone marrow cells stained with HPCA‐1 (CD34) and MY‐9 (CD33) monoclonal antibodies were analyzed by using a fluorescence‐activated cell sorter on or about days 14 and 28, as well as at later times, following BMT in 6 recipients. Single cell cultures of CD34+ cells were also performed to evaluate their in vitro hematopoietic function. CD34+ cells were detectable in bone marrow cells on day 14. More than 80% of CD34+ cells co‐expressed the CD33 antigen, and macrophage (Mac) colony‐forming cells predominated among total colony‐forming cells of CD34+ cells. In normal bone marrow cells, CD34+, CD33+ cells amounted to about 40% of CD34+ cells, and the incidences of erythroid bursts, granulocyte/macrophage (GM) colonies, and Mac colonies were similar to each other. After more than 10 weeks, CD34+, CD33− cells gradually recovered, as erythroid burst colony‐forming cells increased following GM colony‐forming cells. This phenomenon was well‐correlated with the time course of peripheral blood cell recovery. CD34+, CD33+ cells as committed progenitors and CD34+, CD33− cells as multipotent stem cells have distinctive biological behaviors in BMT.
Establishment of Drug Resistance in Human Gastric and Colon Carcinoma Xenograft Lines
Authors: Satta Tetsuya , Isobe Ken‐ichi , Yamauchi Masaji , Nakashima Izumi , Akiyama Seiji , Itou Katsuki , Watanabe Tadashi , Takagi Hiroshi
Published: August 2005

We established multidrug‐resistant human gastric and colon xenograft lines by means of intratu moral injections of four agents, doxorubicin (DXR), cisplatin (CDDP), 5‐fluorouracil (5‐FU) and mitomycin C (MMC), into subcutaneous SC1NU and SW480 tumors once a week or less. Such intermittent drug exposure is commonly used in clinical chemotherapeutic protocols. All xenograft lines acquired resistance to the injected drugs as evaluated by in vivo drug‐resistance tests. Many of the drug‐resistant lines showed various patterns of cross resistance to other drugs. In order to analyze the mechanism of resistance in vivo, we investigated the expression of drug resistance gene, which has been extensively studied in vitro. We used four complementary DNAs (cDNAs) for multidrug resistance (MDR1), glutathione S‐transferase‐ (GST‐), thymidylate synthase (TS) and dehydrofolate reductase (DHFR), as probes. We observed GST‐, DHFR and TS mRNA expression at various levels, but MDR1 mRNA expression was found only in SW480/DXR by the method of poly (A+) RNA selection. Four resistant SW480 lines had higher TS mRNA expressions. Six resistant lines had stronger GST‐ mRNA expression. Five resistant lines had higher DHFR mRNA expression. Drug resistance genes related to the treated drug were also expressed in this in vivo model; MDR1 in SW480/DXR, GST‐ in SW480/CDDP and in SC1NU/CDDP and TS in SW480/5‐FU. In contrast to in vitro resistant lines which have been reported as models of drug resistance, the expression of drug resistance genes in vivo was not always correlated to the acquisition of cross resistance. These resistant xenograft lines and the methods developed to induce drug resistance in vivo should be useful for studies on the mechanism of drug resistance in the clinical setting.
Initiating Activity of Diethylnitrosamine in a Rapid Production Model for Pancreatic Carcinomas in Syrian Hamsters
Authors: Amanuma Toshihiro , Mizumoto Kazuhiro , Tsutsumi Masahiro , Tsujiuchi Toshifumi , Kitazawa Shunji , Hasegawa Kiyohiko , Denda Ayumi , Maruyama Hiroshi , Konishi Yoichi
Published: August 2005

The potential initiating activity of diethylnitrosamine (DEN) was studied in a rapid production model for pancreatic carcinogenesis in hamsters developed in our laboratory incorporating the principle of selection based on resistance to cytotoxicity, originally demonstrated for liver carcinogenesis in rats. Female Syrian golden hamsters were given DEN at a dose of 100 mg/kg body weight or N‐nitrosobis‐(2‐oxopropyI)amine (BOP) at a dose of 70 mg/kg body weight as initiators followed by 3 cycles of augmentation pressure (choline‐deficient diet combined with DL‐ethionine, L‐methionine upon return to basal diet and then administration of 20 mg/kg body weight BOP), and killed 10 weeks after the beginning of the experiment. DEN followed by the augmentation pressure induced a 65% incidence of total pancreatic lesions including 15% carcinomas, while BOP followed by the augmentation pressure induced 100% incidence of total pancreatic lesions and 84.2% for carcinomas. These yields were significantly greater than those observed for augmentation pressure alone. The results thus indicate that DEN possesses weak initiating activity for pancreatic carcinogenesis under the present experimental conditions.
Promoting Effect of Sodium Chloride Solution Mist on the Induction of Papillomas on Syrian Hamster Tracheal Mucosa Following Administration of Diethylnitrosamine
Authors: Karube Toshiaki , Katayama Hiroo , Takemoto Kazuo , Watanabe Shaw
Published: August 2005

The promoting effect of NaCI solution mist was studied in the induction of papillomas on Syrian hamster trachea following single subcutaneous injection of diethylnitrosamine (DEN). Sixty male hamsters were divided into three groups. Group A; Exposure to a 5% NaCl solution mist for 32 weeks following single subcutaneous injection of DEN at a dose of 3 mg/100 g body weight. Group B; Subcutaneous DEN injection alone. Group C; Exposure to the NaCI mist for 32 weeks alone. Total numbers of papillomas on the trachea in each group were 107 in group A, 64 in group B, and 0 in group C (P0.05 between group A and B, P<0.01 between either groups A or B and C). Comparing the incidence of large papillomas with a diameter of more than 2 mm, that in group A hamsters was significantly greater than that of group B (22 large papillomas vs. 8 large papillomas, P<0.01). No difference in the effects on the epithelial cells of the nasal cavity, the bronchial or the alveolar cells in the lung was recognized between groups A and B. The hamsters in group C were not observed to have any changes in any of the respiratory organs. Inhalation of NaCI solution mist is considered to have a promoting effect on the induction of papillomas in the hamster trachea following DEN injection.
Competitive Binding Radioassay for the Determination of 5‐Fluorodeoxyuridine and 5‐Fluorodeoxyuridine‐5′‐monophosphate Levels in Plasma and Tumor Tissue
Authors: Miyata Seiji , Mikami Hidetada , Tai Masaru , Hori Takako , Fujita Hiroshi
Published: August 2005

A competitive binding radioassay was developed to measure 5‐fluoro‐2′‐deoxyuridine (FUDR) as well as 5‐fluoro‐2′‐deoxyuridine monophosphate (FdUMP). FdUMP has been measured by a competitive binding radioassay with thymidylate synthase as the binding enzyme (TS assay). FUDR was enigmatically converted to FdUMP by thymidine kinase, and then the converted FdUMP was measured by the competitive binding assay to determine the concentration of FUDR in plasma and tumor tissue. As little as 100 pg/ml of FUDR or 50 pg/ml of FdUMP can be detected quantitatively by this method. When TS assay and high‐performance liquid chromatography were compared for the measurement of FUDR and FdUMP levels in plasma and tumor tissue of Ehrlich carcinoma (EQ‐bearing mice following administration of FUDR, a close agreement was observed for FUDR levels, though low FdUMP levels were detectable only by the TS assay method. The examination of intracellular metabolism of FUDR in EC cells by this method showed that metabolic conversion of FUDR into FdUMP or 5‐fluorouracil is rapid. Thus, we have established a highly sensitive method for measuring not only FdUMP but also FUDR with TS assay. This should be very useful for experimental and clinical studies on fluoropyrimidines.
Evidence of Sex Difference in DNA Synthesis in Hepatocellular Carcinoma
Authors: Tarao Kazuo , Shimizu Akio , Harada Masaoki , Ono Tetsuo , Kuni Yukifusa , Ohkawa Shinichi , Ito Yoshihiko , Tamai Setsuo , Limori Kazuto , Sugimasa Yukio , Takemiya Shoji , Okamoto Takashi , Inoue Tohru , Kanisawa Masayoshi
Published: August 2005

To clarify sex differences in DNA synthesis in hepatocellular carcinoma (HCC), bromodeoxyuridine labeling indices (BrdU LI) of HCC cells included in tumor biopsy specimens from 12 consecutive male patients and from 5 consecutive female patients all with liver cirrhosis and HCC were examined using an in vitro labeling technique. The mean BrdU LI ± SE of HCC from male patients (7.7 ±0.8%) was significantly (P<0.05) higher than that from female patients (4.4± 1.0%). While 7 of the 12 male HCC patients belonged to the high DNA synthesis group (BrdU LI ≥7.0%), none of the 5 female HCC patients showed high DNA synthesis (P<0.05). We conclude that DNA synthesis in HCC was higher in males than in females.
Enhancement of the Antitumor Effect of Glucose Oxidase by Combined Administration of Hydrogen Peroxide Decomposition Inhibitors Together with an Oxygenated Fluorocarbon
Authors: Higuchi Yoshihiro , Shoin Susumu , Matsukawa Shigeru
Published: August 2005

Glucose oxidase (GO) catalyzes the conversion ofβ‐D‐glucose and molecular oxygen to Dδ‐glucono‐δ‐lactone and H2O2. H2O2 produced by GO was effective in preventing tumor growth in mice bearing not only ascites tumor but also solid tumor. The effect of GO was enhanced by the combined administration of catalase inhibitors such as 3‐aminotriazole, hydroxylamine and sodium azide or the GSH synthesis inhibitor buthionine‐(S,R)‐sulfoximine in vivo. The cytolytic activity of GO against T‐24 cultured cells in vitro was also enhanced by addition of these inhibitors together with GO. In the peritoneal cavity of mice the antitumor effect of GO seemed to be dependent on the amount of oxygen released from oxygenated fluorocarbon‐43 (FC‐O2), an oxygen‐supplying substance. Furthermore, the combined administration of H2O2‐decomposing enzyme inhibitors and FC‐O2 synergistically enhanced the antitumor effect of GO. These results suggest that GO is suitable for antitumor chemotherapy and that the use of inhibitors of H2O2‐decomposing enzymes and FC‐O2 potentiated the GO therapy.
Expression of cripto, a Novel Gene of the Epidermal Growth Factor Family, in Human Gastrointestinal Carcinomas
Authors: Kuniyasu Hiroki , Yoshida Kazuhiro , Yokozaki Hiroshi , Yasui Wataru , Ito Hisao , Toge Tetsuya , Ciardiello Fortunate , Persico M. Graziella , Saeki Toshiaki , Salomon David S. , Tahara Eiichi
Published: August 2005

The expression of mRNA for cripto gene, a novel transforming gene of the epidermal growth factor family, was examined in 20 alimentary tract carcinoma cell lines, 60 surgically resected tumor tissues and their adjacent normal mucosas. Although the cripto mRNA was not detected in esophageal carcinomas or in normal mucosas, it was detected in gastric and colorectal carcinomas. In gastric carcinomas, 2.2 kb cripto mRNA was detected in one cell line, all the gastric carcinoma tissues and their adjacent normal mucosas. Of 23 gastric tumor tissues 8 (34.8%) exhibited a higher mRNA level than normal gastric mucosas. cripto mRNA was detected in 2 out of 6 colorectal carcinoma cell lines. Interestingly, 18 (81.8%) out of 22 colorectal carcinoma specimens expressed a higher level of cripto mRNA than that in normal mucosas. The level of the expression was higher than that in gastric carcinoma tissues. The expression was also correlated to tumor stage of colorectal carcinomas.
Characterization of an Etoposide‐resistant Human K562 Cell Line, K/eto
Authors: Sugawara Isamu , Iwahashi Toshiro , Okamoto Kazuya , Sugimoto Yoshikazu , Ekimoto Hisao , Tsuruo Takashi , Ikeuchi Tatsuro , Mori Shigeo
Published: August 2005

An etoposide‐resistant K562 cell line (K/eto) was obtained by stepwise exposure, in culture, to increasing concentrations of etoposide, without the use of mutagens. This cell line was resistant to etoposide, and slightly resistant to adriamycin, but sensitive to anti‐cancer drugs such as camptothecin, vincristine, actinomycin D and so on. P‐GIycoprotein, the mdr1 gene product, was not detected in this cell line, as assessed by immunocytochemistry, itnmunoprecipitation and flow cytometry. Overexpression of mdr1 mRNA was also not found. Interestingly, expression of 85 kD protein recognized by MRK 20 monoclonal antibody was noted. The level of DNA topoisomerase II protein, detected by antibody staining, decreased concomitantly with a general decrease in DNA topoisomerase II unknotting activity, while DNA topoisomerase I activity was not affected. Cellular accumulation of [3H]etoposide was reduced by 75% in the resistant line compared with parental K562. Karyotype analysis showed that the number of chromosomes in K/eto was 55 and neither a homogeneous staining region nor double‐minute chromosomes were detected. These results indicate that this resistance is not due to an altered interaction between the drug and cellular transport machinery, i.e. MDR1, associated with the “classic” multiple drug resistance phenotype, but rather is due to the existence of other mechanism(s) of resistance, decreased transport of the drug and decreased target enzyme, DNA topoisomerase II.
Second Primary Cancer after Diagnosis of Stomach Cancer in Osaka, Japan
Authors: Hiyama Tomohiko , Hanai Aya , Fujimoto Isaburo
Published: August 2005

The risk of developing a second primary cancer following stomach cancer was estimated from data accumulated in the Osaka Cancer Registry. Of the 38,777 male patients and 22,391 female patients newly diagnosed in the period 1966–1986 who were followed up until the end of 1986, 778 and 267 developed a second cancer other than stomach cancer, respectively, whereas the expected numbers had been 928.8 (RR=0.84, 95%CI=0.78‐0.90) and 297.7 (RR = 0.90, 95%CI = 0.79‐1.01). The risks were higher among younger patients (aged 30–54 at the diagnosis of stomach cancer) than among older patients (aged 55–69 at the diagnosis of stomach cancer). Significantly elevated risks were observed for cancers of the oral cavity & pharynx (RR=l.56), colon (RH = 1.61) and rectum (RR = 1.56) for males, and oral cavity & pharynx (RR = 2.59) for females as second cancers. Results were substantially similar among the localized stomach cancer patients. Among younger male patients with gastrectomy, the risk of developing pancreatic cancer was elevated 10 or more years after stomach cancer diagnosis. The present study suggests the necessity of following up stomach cancer patients in order to enable the early diagnosis of digestive tract cancer.
Effect of Alcohol Ingestion on Carcinogenesis by Synthetic Estrogen and Progestin in the Rat Liver
Authors: Yamagiwa Kentaro , Higashi Shunsaku , Mizumoto Ryuji
Published: August 2005

We examined the effect of alcohol ingestion on hepatocarcinogenesis induced hy oral administration of synthetic female hormones, 0.075 mg of ethynylestradiol (EE) and 6.0 mg of norethindrone acetate (NA), every day for 12 months in female Wistar rats. Administration of 10% ethanol in drinking water for 5 days a week every week resulted in the development of hepatocellular carcinoma (HCC) in 38.4% of the hormone‐treated rats at 12 months, which is approximately 5 times the incidence of HCC observed following EE and NA treatment alone. The number of hyperplastic nodules was significantly higher than the number observed in the case of EE and NA treatment alone after 4 months of the experimental period. The additional alcohol treatment also increased the value of unoccupied nuclear estrogen receptors (ERn) at months 6 and 8 of the experimental period, and increased the value of total ERn in the rat liver after 6 months of the experimental period. This indicates that additional alcohol treatment may increase occupied ERn (estrogen‐ER complex) in the rat liver. A 32P‐postlabeling analysis of liver DNA revealed that the maximum number of extra spots consisting of modified nucleotides induced by EE and NA appeared earlier when the additional alcohol treatment was imposed. Consequently, alcohol affects the hepatocarcinogenesis by EE and NA, promoting not only the change in kinetics of ER, but also DNA adduct formation induced by EE and NA in the rat liver.