bluuebunny/crossref_metadata_2025 huggingface dataset:
Polyclonal Antibodies to DNA Modified with 4‐Nitroquinoline 1‐Oxide: Application for the Detection of 4‐Nitroquinoline 1‐Oxide‐DNA Adducts in vivo
Authors: Morita Toshiteru , Ikeda Sachiya , Minoura Yasushi , Kojima Misaki , Tada Mariko
Published: August 2005

Antibodies against 4‐nitroquinoline 1‐oxide (4NQO) adducts were elicited in rabbits immunized with 4NQO‐modified DNA complexed with methylated bovine serum albumin. In enzymelinked immunosorbent assay (ELISA), the antibodies could recognize either denatured or native 4NQO‐modified DNA, but not unmodified DNA, DNA modified with other carcinogens or free 4NQO derivative. Modification levels as low as 5 μmol of adduct per one mole DNA nucleotide (5 adducts/106 nucleotides) can be easily detected by the competitive ELISA. Indirect immunofluorescence staining by anti 4NQO‐DNA antibody indicated that the antibodies bound specifically to the nuclei of normal human skin fibroblast cells treated with 4NQO. The intensity of fluorescence was proportional to the dose of 4NQO used to treat the cells, and the fluorescence positive cells could be detected after treatment with 0.25μM 4NQO (which resulted in the formation of 104 adducts per cell). Applying the competitive ELISA to the quantitation of DNA‐adducts in rats treated with 4NQO, it was confirmed that the sensitivity of immunochemical assays was equivalent to that of isotopic assays. These methods should be helpful in studies on the formation of adducts and their removal in cells and tissues.
The Dynamics of Tumor Cords in an Irradiated Mouse Mammary Carcinoma with a Large Hypoxic Cell Component
Authors: Moore James V.
Published: August 2005

The tumor cord model represents a histologically based framework for interpretation of radiobiological phenomena, particularly the resistance to radiation conferred by absence of oxygen. For the mammary carcinoma T50/80 grown in B6D2F1 male mice, average oxygenation was poor, based on tumor growth delay after irradiation. There was no improvement in radiobiological oxygenation for several days after a high dose of radiation. This was consistent with events in the cords of the tumor, where although up to 20% of all cells became pyknotic by 8 hr, the cords did not shrink for at least 2 days. The cellular kinetics of populations of intact and dead cells, adjacent to and remote from the capillaries of the cords, were examined for up to 60 hr after irradiation and it was found that: (i) before treatment, average LI (adjacent) was 13% and LI (remote) was 2%, (ii) after irradiation, cells expressed pyknosis after passing through the S phase of the cell cycle, so that (iii) at early intervals there was a larger proportional rise in pyknotic cells in the adjacent than the remote zone. However, (iv) at later intervals there was always a higher proportion of dead cells in the remote zone.
Immunochemical and Immunohistological Analyses of Tumor‐associated Antigens Defined by Murine Monoclonal Antibodies against Human Pancreatic Carcinoma Cells
Authors: Koyama Shohei , Mukai Ryozaburo , Fukao Katashi , Osuga Toshiaki
Published: August 2005

Two murine monoclonal antibodies, SK‐930 (isotype IgG2a) and SK‐117 (isotype IgG1), were produced from spleen cells of mice immunized against human pancreatic carcinoma cell lines, MIA‐PaCa 2 and Panc‐1. With the use of the avidin‐biotin‐immunoperoxidase technique, the SK‐930 and SK‐117 antibodies detected an antigen found in 24 and 23 formalin‐fixed tissue sections, respectively, of tumors obtained from 30 different patients with pancreatic carcinoma. Reactivity was also frequently found with tumors of the gallbladder, bile duct, stomach, colon and esophagus, while a large panel of normal human tissues, including normal pancreatic tissues, displayed little reactivity. These observations suggest that SK‐930 and SK‐117 are of value in identifying tumor‐associated antigen (TAA) expressed in pancreatic carcinoma and other carcinomas of the digestive system. SK‐930 antibody immunoprecipitated a 134 kilodalton molecule from extracts of 125I‐ or [35S]methionine‐ or [3H]glucosamine‐labeled tumor cells. The SK‐117‐defined antigen corresponds to 152/137 kilodalton molecules. Moreover, cytofluorometric analyses showed that cells treated with periodic acid exhibited greatly decreased reactivity to the two antibodies, but cells treated with neuraminidase, trypsin or pronase showed unchanged reactivity. The findings suggest that the epitopes of the novel TAA expressed on pancreatic carcinoma cells are carbohydrate moieties.
The Screening of Cattle with Potential for Developing Leukemia by Using Monoclonal Antibody against Bovine Leukemia Cells
Authors: Onuma Misao , Yasutomi Yasuhiro , Okada Hiroyuki M. , Matsukawa Kiyoshi , Yoshikawa Hiroyasu , Yoshikawa Takashi , Okada Kōsuke , Takahashi Kiyoshi , Kirisawa Rikio , Kawakami Yoshimi
Published: August 2005

Tumor cells from cattle with enzootic bovine lymphosarcoma (EBL) have a tumor‐associated antigen (TAA) which is distinct from bovine leukemia virus (BLV)‐induced antigens. We were able to sacrifice 8 TAA‐positive cattle with no clinical signs of EBL and to examine whether or not they had gross or histological tumors. At necropsy, 4 animals had tumors macroscopically. Three animals had no tumors histologically but had initial lesions showing follicular hyperplasia and had the TAA on affected lymph nodes. The remaining one showed medullary hyperplasia in the spleen but there were no findings of tumors. These results suggest that most BLV‐infected cattle which are TAA‐positive but have no clinical signs of EBL, do have tumors and have a higher potential for developing EBL in the future when compared to BLV‐infected but TAA‐negative cattle.
A POSSIBLE ROLE OF GLUCOCORTICOIDS: AN INTRINSIC INHIBITOR OF THE CYTOTOXIC ACTIVITY OF TUMOR NECROSIS FACTOR
Authors: Abe Shigeru , Yamamoto Takahiko , Iihara Seiji , Yamazaki Masatoshi , Mizuno Den'ichi
Published: August 2005

The cytotoxic activity of tumor necrosis factor (TNF) against L929 fibroblasts in vivo was non‐competitively inhibited by physiological concentrations of glucocorticoids such as hydrocortisone (10‐7M), corticosterone (5 × 10‐8M) and dexamethasone (5 × 10‐9M). The inhibition was abolished by the addition of actinomycin D (0.5 μg/ml) or cycloheximide (4μM). A phospholipase A2 inhibitor, quinacrine (2 × 10‐6M), also inhibited the TNF cytotoxicity. These findings suggest that the antitumor cytotoxic reaction by TNF is regulated by glucocorticoid through some mechanism involving de novo transcription and translation and that this regulatory mechanism may involve inhibition of phospholipase A2 activity.
Decreased Sensitivity to Phalloidin of Normal‐looking Rat Hepatocytes after Short‐term 2‐Acetylaminofluorene Feeding
Authors: Mitaka Toshihiro , Tsukada Hideyuki
Published: August 2005

Male F344/DuCrj rats were fed a diet containing 0.02% 2‐acetylaminofluorene (2‐AAF) for 1 or 3 weeks, and then fed a basal diet for 2 days, 2 weeks, 8 weeks, 22 weeks or 36 weeks. Hepatocytes were isolated from the liver by collagenase perfusion, and their sensitivity to phalloidin, in terms of the formation of multiple cytoplasmic blebs, was examined. The sensitivity of gamma‐glutamyltransferase (GGT)‐negative hepatocytes decreased on the 22nd and 36th weeks after withdrawal of 2‐AAF feeding, and that of GGT‐positive cells decreased on the 36th week. Induction of a small number of foci positive for the placental form of glutathione S‐transferase (GSTP) was observed in the liver of all rats on the 8th, 22nd and 36th weeks after the withdrawal of the carcinogen. However, the total area of the foci was estimated to account for less than 0.2% of liver tissues even on the 36th week. Therefore, the decrease in phalloidin sensitivity of hepatocytes, particularly of GGT‐negative hepatocytes, on the 22nd and 36th weeks after 2‐AAF withdrawal is suggested to be a result of a decrease in the sensitivity of otherwise normal‐looking hepatocytes, which may be precursors of the cells forming the preneoplastic foci.
T‐cell Receptor β‐Chain Gene Expression in B‐lineage Acute Lymphoblastic Leukemia
Authors: Tawa Akio , Kawa‐Ha Keisei , Ishihara Shigehiko , Yumura‐Yagi Keiko , Terada Naohiro , Murata Mitsunori , Izumi Yutaka , Yabuuchi Hyakuji
Published: August 2005

The T‐cell receptor β‐chain (Tβ) gene expression was examined in 16 children with B‐lineage acute lymphoblastic leukemia (ALL), including eight patients with rearrangement of the Tβ gene as well as immunoglobulin (Ig) heavy chain gene rearrangement. In contrast to the 1.3 kb full‐length transcripts of the Tβ gene observed in T‐lineage leukemia and lymphoma cells, no transcript of the Tβ gene was detected in 10 patients, including four with Tβ gene rearrangement. Low levels of Tβ transcripts were found in three patients with Tβ gene rearrangement and two patients without Tβ gene rearrangement, but those transcripts were truncated. In contrast to those findings, a single patient with Tβ gene rearrangement showed abundant 1.3 kb Tβ transcripts. These data indicate that Tβ gene expression is not restricted to T‐lineage cells and demonstrate the heterogeneity of B‐lineage ALL at the expression level of the Tβ gene. Our findings also suggest that Tβ gene expression is not always accompanied with Tβ gene rearrangement.
Separation of the Tumor Rejection Antigen of Rous Sarcoma Virus‐induced Murine Fibrosarcoma
Authors: Suda Takashi , Shimizu Jun , Mizushima Yumiko , Fujiwara Hiromi , Hamaoka Toshiyuki
Published: August 2005

The tumor antigen capable of inducing tumor resistance (tumor rejection antigen; TRA) was separated and some of its physicochemical properties were characterized. Cytosol and plasma membrane fractions were separated from Rous sarcoma virus (RSV)‐induced CSA1M tumor cells. Immunization with membrane but not cytosol fraction of these tumor cells together with complete Freund's adjuvant resulted in complete protection against subsequent challenge with viable CSA1M cells. The TRA activity contained in the membrane fraction was recovered in the sodium dodecyl sulfate (SDS)‐solubilized fraction after the SDS‐extraction of CSA1M membranes. This CSA1M SDS‐solubilized preparation gave protection against syngeneic RSV‐induced CSA9F tumor cells as well as the homologous tumor cell type, but failed to induce resistance to RSV‐unrelated tumor cells. The membrane or SDS‐solubilized fraction from RSV‐unrelated tumor cells was unable to generate anti‐CSA1M protective immunity. Physicochemical analyses have demonstrated that TRA activity in the SDS‐solubilized fraction was completely abolished by treatment with proteinase K but was only marginally affected after treatment with glycosidase mixture. When the SDS‐solubilized preparation was applied to a Sephacryl S‐300 superfine column, TRA activity was recovered in the range of molecular weight of 50‐90 kD. Further fractionation of this TRA‐positive fraction by SDS‐polyacrylamide gel electrophoresis revealed that the molecular size of TRA is 56–68 kD. These results indicate that membrane proteins which were isolated from CSA1M tumor cells and have a molecular size of about 60 kD are capable of inducing RSV‐induced tumor‐specific in vivo protective immunity.
Mechanism of Methotrexate‐sensitivity of Choriocarcinoma Cells in Culture
Authors: Indue Takami , Nagura Eiichi , Toyoda Tetsuya , Ishizuka Takao , Gotoh Setsuko , Kawashima Kohei , Tomoda Yutaka , Nagai Yoshiyuki
Published: August 2005

Four cell lines established from choriocarcinoma were compared for sensitivity to methotrexate (MTX). In this paper, we have compared the relative gene copy number of dihydrofolate reductase (DHFR), the target enzyme of methotrexate (MTX), in order to clarify whether or not amplification of the gene is involved in the relative resistance to MTX observed for one of the cell lines, designated NaUCC‐1, which is 4‐ to 5‐fold more resistant to MTX as compared with the other cell lines and exhibits a reduced uptake of [3H]MTX. Neither dot blot nor Southern blot hybridization revealed any significant difference in the gene copy number among the four cell lines. Therefore, the resistance to MTX of the NaUCC‐1 line is explained by a reduced uptake of the drug, rather than amplification of the target gene.
Strain Differences in N‐Butyl‐N‐(4‐hydroxybutyl)nitrosamine Bladder Carcinogenesis in Rats
Authors: Nakanowatari Jun‐ichi , Fukushima Shoji , Imaida Katsumi , Ito Nobuyuki , Nagase Sumi
Published: August 2005

Differences in susceptibility of the urinary bladder epithelium to N‐butyl‐N‐(4‐hydroxybutyl)‐nitrosamine (BBN) in various strains were examined. In experiment 1, 5 strains of male rats were given 0.025% BBN in the drinking water for 8 weeks followed by drinking water without BBN for 32 weeks. Analbuminemic rats (NAR) and ACI rats had high incidences of urinary bladder lesions (papillary or nodular hyperplasia, papilloma and carcinoma), F344 and Wistar rats had low incidences, and Sprague‐Dawley (SD) rats showed an intermediate incidence. Carcinoma area was largest in NAR rats followed in decreasing order by SD, ACI and F344 rats. The extent of tumor invasion was higher in NAR and ACI rats than in SD rats. In experiment 2, the 5 strains of male rats were administered 0.025% BBN in the drinking water. Some rats from each group were killed after each of weeks 4 and 8. The urinary bladder of ACI and NAR rats given BBN had the most marked lesions observed by scanning electron microscopy, with less marked changes in SD rats. F344 and Wistar rats showed the weakest response. Cytochrome P‐450 content of the liver in ACI rats treated with BBN for 4 weeks was significantly higher than those of the controls. Cytochrome P‐450 and Cytochrome b5 contents of the control and BBN‐treated rats were significantly higher in ACI and SD rats than in Wistar, F344 or NAR rats. These results indicate that there are strain differences in the urinary bladder response to BBN.
Combined Use of α‐Difluoromethylornithine and an Inhibitor of S‐Adenosylmethionine Decarboxylase in Mice Bearing P388 Leukemia or Lewis Lung Carcinoma
Authors: Nakaike Shiro , Kashiwagi Keiko , Terao Kiyoshi , Iio Kokoro , Igarashi Kazuei
Published: August 2005

The antitumor and antimetastatic effects of α‐difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, combined with an inhibitor of S‐adenosylmethionine decarboxylase, either methylglyoxal bis(guanylhydrazone) (MGBG) or ethylglyoxal bis(guanylhydrazone) (EGBG), were studied in mice bearing P388 leukemia or Lewis lung carcinoma. Although EGBG is a more specific inhibitor of polyamine biosynthesis than the widely used MGBG, the antitumor effect of the DFMO‐EGBG combination on P388 leukemia‐bearing mice was less than that of the DFMO‐MGBG combination. The prolongation of survival time by the DFMOC1000 mg/kg)‐MGBG(25 mg/kg) combination was 2.65‐fold, while that of the DFMO(1000 mg/kg)‐EGBG(50 mg/kg) combination was 1.34‐fold. When mice were fed a polyamine‐deficient diet, stronger antitumor effects were exerted; the prolongation of survival time by the DFMO‐MGBG and the DFMO‐EGBG combinations was 2.89‐fold and 2.03‐fold, respectively. The antitumor effect of combined use of the two polyamine antimetabolites with mice on normal and polyamine‐deficient diets correlated with a decrease of polyamine charge contents in the tumor cells. The above in vivo results were confirmed clearly in the KB cell culture system. The antimetastatic activity of DFMO on Lewis lung carcinoma‐bearing mice was strengthened by the addition of MGBG or EGBG. The antimetastatic activity of the DFMO‐MGBG or DFMO‐EGBG combination did not parallel the polyamine charge contents in the primary tumor and blood.
Oxic and Hypoxic Cells in a Murine Squamous Cell Carcinoma
Authors: Takai Yoshihiro , Sakamoto Kiyohiko , Okada Shigefumi
Published: August 2005

[125I]Iododeoxyuridine labeling of a squamous cell carcinoma and follow‐up of 125I activity at the tumor in situ revealed that the 125I activity remained at a constant level from the 24th to the 100th hour post‐labeling and then decreased with a half time of about 200 hr. Autoradiographic studies with [3H]thymidine showed that the tumor cells were labeled around capillaries, spread through the corded structure (the cord) and finally reached the necrotic regions. One could speculate that the constant 125I period represents the transit time of the labeled cells through the cord and that the decline occurs mostly in the necrotic regions. X‐Irradiation shortened the constant period of 125I activity by about 24 hr and accelerated the declining rate in a dose‐dependent manner. When tumors were made hypoxic by clamping the legs, the declining rate decreased significantly. When misonidazol (a hypoxic radiosensitizer) was administered before X‐rays, the declining rate increased to a level higher than that of the oxic tumors. From the time course studies, it was suggested that the tumor cells immediately after 125I‐labeling were oxic, that they became gradually hypoxic during their transit through the cord and that they became anoxic when they reached the necrotic regions.
INDUCTION AND PROMOTION OF γ‐GLUTAMYLTRANSPEPTIDASE‐POSITIVE FOCI IN THE RAT LIVER BY METHYLGLYOXAL
Authors: Martelli Antonietta , Ghia Marco , Mereto Eugenio , Marinari Umberto Maria , Brambilla Giovanni
Published: August 2005

The effect of pre‐(initiation) and post‐(promotion) administration of methylglyoxal (MG) on the induction of γ‐glutamyltranspeptidase (GGT)‐positive foci in the liver of F344 male rats was investigated. GGT‐positive foci were produced in doserelated amounts by 0.05 and 0.2% MG in drinking water, either when administered to uninitiated rats or when given in the promotion phase.
MEDULLASIN INDUCES ACTIVATED KILLER CELLS FROM HUMAN LYMPHOCYTES
Authors: Aoki Yosuke
Published: August 2005

Treatment of human lymphocytes with a physiological amount of medullasin, a serine protease found in bone marrow cells, resulted in the induction of activated killer cells which can lyse both natural killer‐sensitive and ‐resistant target cells. The optimum concentration of medullasin was 20 μg/ml when lymphocytes were treated with the protease at 37° for 60 min. Kinetic studies of the induction revealed that the maximum induction was achieved 24 hr after medullasin treatment.
Natural Human Interferon‐γ Derived from Lipopolysaccharide‐stimulated Human Myelomonocytic HBL‐38 Cells
Authors: Ando Shunsaku , Ohta Tsunetaka , Tanimoto Tadao , Sano Osamu , Yamauchi Hiroshi , Andoh Osamu , Torigoe Kakuji , Kurimoto Masashi
Published: August 2005

A human myelomonocytic cell line, HBL‐38 cells, propagated in vivo, spontaneously produced interferon (IFN)‐γ and IFN‐α. Whereas hemmagglutinating virus of Japan (HVJ) enhanced the production of IFN‐α, bacterial lipopolysaccharide (LPS) markedly enhanced the production of IFN‐γ. LPS could be replaced with lipid A. Furthermore, the enahancement of production of IFN‐γ by LPS was completely abolished by polymixin B. IFN‐γ derived from LPS‐stimulated HBL‐38 cells was purified to homogeneity and characterized. The apparent molecular weight, subspecies composition, amino acid sequence and glycosylated sites were in agreement with those of the product of normal human peripheral blood lymphocytes (PBL). These results indicate that the myelomonocytic HBL‐38 cells, not a T‐cell line, can also produce IFN‐γ identical to the product of normal human PBL.
Co‐amplification of c‐myc and c‐erbB‐2 Oncogenes in a Poorly Differentiated Human Gastric Cancer
Authors: Tsuchiya Terumasa , Ueyama Yoshito , Tamaoki Norikazu , Yamaguchi Sachiko , Shibuya Masabumi
Published: August 2005

c‐erbB‐2 oncogenc has been reported to be frequently amplified in differentiated, tubular type of gastric cancer. Here we report a human gastric cancer which bore co‐amplified c‐myc and c‐erbB‐2 oncogenes: a portion of the amplified c‐erbB‐2 oncogene was found to be rearranged. Furthermore, c‐myc and c‐erbB‐2 oncogenes were over‐expressed in the tumor cells. In contrast to the previous reports, this gastric adenocarcinoma was classified as a poorly differentiated type, and was highly tutnorigenic in nude mice. These results might suggest that activated c‐myc and c‐erbB‐2 oncogenes co‐operate and influence the malignant state of some gastric carcinomas.
Diacylglycerols Enhance the Anti‐tumor Effect of Glucocorticoid on L5178Y Lymphoblasts in vivo
Authors: Fukusen Naomi , Kido Hiroshi , Kato Yasuhisa , Ishidoh Kazumi , Katunuma Nobuhiko
Published: August 2005

1,2‐Dioleoyl‐rac‐glycerol, a potent activator of protein kinase C, was found to enhance the growth‐inhibitory effect of triamcinolone acetonide on L5178Y lymphoblasts in adrenalectomized, male DBA/2 mice. On the other hand, in mice without adrenalectomy, it markedly inhibited tumor growth without increasing the plasma level of corticosterone or adrenocorticotropic hormone or reducing the body weight. These results suggest that diacylglycerol enhances the action of endogenous glucocorticoid to a sufficient level to inhibit the growth of lymphoblasts. Of various diacylglycerols with different carbon chain lengths tested, 1,2‐dioleoyl‐rac‐glycerol was the most potent growth inhibitor and was maximally effective at a dose of above 30 μg/100 g body weight. This finding suggests that diacylglycerols may he useful for enhancing the antitumor effect of a low dose of glucocorticoid or endogenous glucocorticoid on lymphoblasts without any significant side effect.
Expression of P‐Glycoprotein mRNA in Human Gastric Tumors
Authors: Sugimoto Yoshikazu , Asami Noriko , Tsuruo Takashi
Published: August 2005

We have isolated a cDNA clone, pCA12–2, from a 2 gt11 cDNA library of an adriamyciii‐resistant subline of human myelogenous leukemia K562 (K562/ADM) by plaque hybridization with the 2.6 kb genomic probe of P‐glycoprotein reported previously. The cDNA pCA12–2 was identified as the 3′‐part of P‐glycoprotein cDNA by dideoxy sequencing. By using the cDNA probe, expression of P‐glycoprotein mRNA was examined in human gastric xenograft lines transplanted in nude mice and clinical samples of human gastric normal tissues and tumors. Five gastric tumor xenograft lines expressed low but significant levels of P‐glycoprotein mRNA. The extent of expression was higher in some cases than that observed for R1–3, a weakly drug‐resistant subline of K562. Normal gastric tissues from three patients expressed similar levels of P‐glycoprotein mRNA and the extent of expression was slightly higher than that of R1–3. Two of three gastric tumor samples expressed higher levels of mRNA than normal gastric tissues. These results suggest that the intrinsic insensitivity of human gastric cancers to chemotherapy could be partly explained by the expression of P‐glycoprotein.
Effect of Adriamycin on DNA, RNA and Protein Biosyntheses in Mouse Tissues, in Connection with Its Cardiotoxicity
Authors: Sazuka Yasuyuki , Tanizawa Hisayuki , Takino Yoshio
Published: August 2005

We examined whether the cause of the remarkable decreases in the activities of lipid peroxidationpreventive enzymes in the heart of adriamycin (ADR)‐treated mice might be related to inhibition of DNA, RNA or protein biosynthesis. It was found that biosyntheses of DNA, RNA and protein in the heart, liver and kidney of mice were markedly inhibited by ADR (15 mg/kg, ip). The inhibitory effects of ADR on each type of biosynthesis were particularly marked in the heart among the tissues examined. Strong correlations between the percentage inhibition of DNA and protein biosynthesis by ADR, and the percentage decrease in the activities of lipid peroxidationpreventive enzymes were observed in the heart, liver, kidney and lung, especially for the decrease of glutathione peroxidase activity and the inhibition of DNA and protein biosyntheses. We also found that marked decreases of DNA, RNA and protein biosyntheses in ADR‐treated mice occurred not only in the heart but also in tumor tissues. From these results, we conclude that the increment of cardiac lipid peroxide in ADR‐treated mice, which is closely related to the cardiotoxicity of ADR, results from inhibition of DNA, RNA and protein biosyntheses after the distribution of ADR.
In vivo Antitumor Mechanism of Natural Human Tumor Necrosis Factor Involving a T Cell‐mediated Immunological Route
Authors: Asami Tetsuya , Imai Meroni , Tanaka Yasuo , Hosaka Yoshitaka , Kato Kazuharu , Nakamura Norio , Horisawa Yoshifumi , Ashida Yoshikazu , Kanamori Toshinori , Nobuhara Masahiro , Kurimoto Masashi
Published: August 2005

We have investigated the in vivo antitumor mechanism of natural human tumor necrosis factor (n‐TNF) isolated from a culture of human leukemic B cell line (BALL‐1), especially its action as an immunomodulator, and found that the in vivo antitumor effect of n‐TNF on Meth A sarcoma implanted in BALB/c mice pretreated with monoclonal antibody against T cell‐specific surface antigen (Thy‐1) was significantly diminished. Furthermore, when BALB/c mice were treated with T cell subset‐specific monoclonal antibodies, anti‐L3T4 or anti‐Lyt‐2.2, the antitumor effect of n‐TNF on Meth A sarcoma was significantly reduced. Therefore, it was suggested that the in vivo antitumor mechanism of n‐TNF might involve a T cell‐mediated immunological route.
Induction of Lymphoma in CDF1 Mice by the Food Mutagen, 2‐Amino‐l‐methyl‐6‐phenylimidazo[4,5‐b]pyridine
Authors: Esumi Hiroyasu , Ohgaki Hiroko , Kohzen Emiko , Takayama Shozo , Sugimura Takashi
Published: August 2005

The mutagenic compound, 2‐amino‐l‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), originally isolated from cooked beef, was tested for carcinogenicity in CDF1 mice of both sexes. When PhIP was given in the diet at a concentration of 0.04%, high incidences and early appearances of lymphomas were observed in both sexes during the 579‐day experiment.
A Variant Schmidt‐Ruppin Strain of Rous Sarcoma Virus with Increased Affinity for Mammalian Cells
Authors: Kawai Sadaaki , Nishizawa Makoto , Shinno‐Kohno Hideko , Shiroki Kazuko
Published: August 2005

SR‐RSV‐D(H), a variant virus with extremely high tropism for mammalian cells, was isolated by passage of the Schmidt‐Ruppin strain of Rous sarcoma virus of subgroup D (SR‐RSV‐D) through hamster cells. This variant virus has acquired an altered envelope glycoprotein, encoded by the env gene, that has high affinity for receptors on the surface of mammalian cells. The variant virus transforms rat cells at about 100 times the efficiency of the parental virus, SR‐RSV‐D(S), as assayed by focus formation. Addition of amphotericin B (Fungizone) to the medium at a concentration of 0.2 μg/ml completely inhibited rat cell transformation by SR‐RSV‐D(H), possibly by blocking virus penetration into the cells, whereas the drug showed no inhibitory effect on transformation of chick embryo flbroblast (CEF) cells by the variant virus or on transformation of rat cells by the parental virus. The efficiency of transformation of rat cells by the variant virus was much less than its efficiency of transformation of CEF cells. Analysis of infection of rat cells suggested that the virus can infect rat cells as efficiently as CEF cells but that rat cells were not transformed by the virus as fully as CEF cells because of inefficiency of some post‐penetrational step involved in viral gene expression. The finding that El AY cells, rat cells expressing adenovirus El A gene, were transformed by SR‐RSV‐D(H) as efficiently as CEF cells supports this conclusion and suggests that expression of the E1A gene in rat cells may overcome the defect in the transforming step(s) in rat cells.
Two Populations of Mouse Lymphokine‐activated Killer Cells Separated by Use of Soybean Agglutinin
Authors: Takano Mariko , Okada Tomoko , Maruyama Toshiyuki , Harada Kenji , Imai Yasuyuki , Osawa Toshiaki
Published: August 2005

We separated lymphokine‐activated killer (LAK) cells induced from spleen cells of BALB/c mice by culturing with recombinant interleukin‐2 (rIL‐2) into soybean agglutinin‐positive (SBA+) and soybean agglutinin‐negative (SBA‐) fractions with a cell sorter at the time when LAK activity reached a maximum (day 3). We found that the cells with LAK activity were enriched in the SBA+ fraction. Analysis of cell surface phenotypes revealed that the SBA+ cells are of non‐T cell origin, while the SBA‐ fraction consists of T cells. We also found that the large granular lymphocyte (LGL) fraction of spleen cells obtained with a Percoll gradient became SBA+ after culture for 3 days with rIL‐2, whereas cells of high density did not. The change in SBA binding sites was also examined on C57BL/6 mouse spleen cells and we found that NK1.1+ non‐T cells selectively acquire SBA binding sites at an early stage of activation with rIL‐2. On the other hand, sorted SBA‐ cells gradually acquired SBA binding sites on extended culturing with rIL‐2. These results suggest that the expression of SBA binding sites is related to the stage of cell activation with rIL‐2, though cells of the NK‐lineage became SBA+ at an earlier period of a culture with rIL‐2 than cells of the T‐lineage. Utilizing these findings, we separated NK‐derived LAK cells by means of SBA‐binding, and used the separated cells for adoptive immunotherapy for experimental pulmonary metastasis. We found that SBA+‐NK cell‐derived LAK cells showed stronger activity for the inhibition of experimental pulmonary metastasis than SBA ‐T cell‐derived LAK cells.
Growth Inhibition and Differentiation of Murine Melanoma B16‐BL6 Cells Caused by the Combination of Cisplatin and Caffeine
Authors: Tsuchiya Hiroyuki , Tomita Katsuro , Yasutake Hidetoshi , Ueda Yoshimichi , Tanaka Motohiro , Sasaki Takuma
Published: August 2005

We preliminarily investigated the combined effects of cisplatin and caffeine on murine melanoma B16‐BL6 cells in vitro. When caffeine was added before or simultaneously with cisplatin, there was little growth inhibition. The addition of 2.0 mM caffeine after 1 h of exposure to cisplatin inhibited growth and induced cell differentiation. This treatment resulted in fewer cells, and the numbers of melanosomes and mitochondria and the amount of Golgi's complex and endoplasmic reticulum were increased. DNA histograms obtained by flow cytometry showed that cells treated with cisplatin alone accumulated in the G2/M phase, with a partial G2 block. The addition of 2.0 mM caffeine after 1 h of treatment with cisplatin reduced this block. Caffeine caused murine melanoma B16‐BL6 cells treated with cisplatin to differentiate, and this inhibited growth.
Enhancing Effect of High Fat Diet on 4‐Nitroquinoline 1‐Oxide‐induced Pulmonary Tumorigenesis in ICR Male Mice
Authors: Imaida Katsumi , Sato Hidetaka , Okamiya Hideaki , Takahashi Michihito , Hayashi Yuzo
Published: August 2005

The effects of dietary high fat on 4‐nitroquinoline 1‐oxide (4NQO)‐induced lung tumorigenesis were investigated in male ICR mice. Two groups of mice were initially given a single subcutaneous injection of 4NQO at a dose of 15 mg/kg and, thereafter, fed either 20% corn oil‐supplemented diet or a standard basal diet. Two further groups were maintained on the high fat diet or standard diet without administration of 4NQO. Mice were killed at weeks 15, 18 and 25 and the incidence of lung tumors at each time point was found to be significantly increased in the 4NQO/high fat diet group as compared to the 4NQO/standard diet group in terms of both incidence of tumor‐bearing mice and the number of lesions per mouse. The results thus indicate that dietary high fat can enhance 4NQO‐induced lung tumorigenesis in mice.
Inhibitory Effect of (—)‐Epigallocatechin Gallate on Carcinogenesis with N‐Ethyl‐N′‐nitro‐N‐nitrosoguanidine in Mouse Duodenum
Authors: Fujita Yoshihiro , Yamane Tetsuro , Tanaka Masumi , Kuwata Katsuya , Okuzumi Junichi , Takahashi Toshio , Fujiki Hirota , Okuda Takuo
Published: August 2005

(—)‐Epigallocatechin gallate (EGCG) is the main polyphenolic constituent of green tea infusion and inhibits tumor promotion by teleocidin in two‐stage carcinogenesis on mouse skin. In this work, EGCG was found to inhibit tumor promotion in the gastrointestinal tract in a model system of mouse duodenal carcinogenesis with N‐ethyl‐N′‐nitro‐N‐nitrosoguanidine. The duodenal tumors that developed were studied stereomicroscopically and histologically.
Epidemiologic Survey on Lung Cancer with Respect to Cigarette Smoking and Plant Diet1
Authors: Sakai Ryoji
Published: August 2005

This case‐control study of lung cancer was based on a cross‐sectional questionnaire survey of inpatients at 5 general hospitals in Okinawa, Japan, from 1982 to 1987. The purpose of the study was to clarify the relations of lung cancer to cigarette smoking and plant diet. Ingestion frequencies of 17 major dietary plants and/or herbs were obtained by means of a questionnaire interview. As eligible subjects for a case‐control analysis, there were 673 respondents aged over 30 years with clear smoking history, age, sex and diagnosis. Psychiatric patients were excluded. Odds ratios of newly diagnosed lung cancer were calculated by the Mantel‐Haenszel procedure. A pair consisted of a case and two controls which were selected randomly by using multivariate caliper matching. Sixty‐four pairs matched for age (±5) and sex showed a significantly high odds ratio of 2.9 (P< 0.0005). However, three male groups who were categorized by the number of cigarettes smoked did not exhibit dose‐dependency of lung cancer on smoking. Lung cancer was more prevalent in ex‐smokers than in current smokers. Case‐control analyses by male generations revealed that lung cancer incidence was age‐dependent, and there was a clear dose‐response relationship between smoking and lung cancer in males in their sixties. A case‐control analysis of each of 17 edible plants based on 44 pairs who were matched for age (±5), sex and smoking history demonstrated that the odds ratio of aloe (Aloe arborescens Millvar. natalensis Berger) was 0.5 (P<0.1), suggesting that the aloe may prevent human carcinogenesis at various sites.
Promotion by Nialamide of Gastric Carcinogenesis Induced by N‐Methyl‐N′‐nitro‐N‐nitrosoguanidine in Wistar Rats
Authors: Tatsuta Masaharu , Iishi Hiroyasu , Baba Miyako , Taniguchi Haruo
Published: August 2005

The effects of nialamide, a monoamine oxidase inhibitor, on the incidence, number, and histology of gastric cancers induced by N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) were investigated in male Wistar rats. Rats were given subcutaneously 50 mg/kg body weight of nialamide in depot form every other day after 25 weeks of oral treatment with MNNG. Prolonged alternate‐day administration of nialamide caused a significant increase in the incidence and number of gastric cancers of the glandular stomach in week 52, However, it did not affect the histology of the cancers. Nialamide also caused a significant increase in tissue norepinephrine concentrations in the gastric wall and in the labeling indices of the gastric mucosae. However, nialamide had no influence on serum gastrin levels in the fasting state and after re‐feeding. These findings indicate that nialamide promotes gastric carcinogenesis and that this may be related to its effects in increasing norepinephrine in the gastric wall and stimulating proliferation of gastric epithelial cells.
Enhancing Effect of Ethanol on Aflatoxin B1‐induced Hepatocarcinogenesis in Male ACI/N Rats
Authors: Tanaka Takuji , Nishikawa Akiyoshi , Iwata Hitoshi , Mori Yoshio , Kara Akira , Hirono Iwao , Mori Hideki
Published: August 2005

The modifying effect of ethanol (EtOH) on aflatoxin B1 (AFB1)‐induced hepatocarcinogenesis was examined in male ACI/N rats by chronic treatment at the post‐initiation phase. Rats received an ip injection of AFB1 (1.5 mg/kg) twice a week for 10 weeks (a total of 20 doses). Following a week of acclimation, they were given 10% EtOH as drinking water for 56 weeks. The effect of EtOH on the hepatocarcinogenesis was evaluated in terms of the incidence of altered hepatocellular foci and neoplasms at the end of the experiment. Exposure to AFB1 alone induced a substantial number of altered foci (6.98 iron‐excluding foci/cm2) in rats. The number of altered liver cell foci in rats receiving AFB1 followed by EtOH was significantly increased (26.39 iron‐excluding foci/cm2). In the rats given EtOH after AFB1 the total area and mean diameter of both iron‐excluding foci and altered foci identified in hematoxylin and eosin‐stained sections were significantly higher than in the rats exposed to AFB1 alone. The incidence of liver cell tumors of the group given AFB, and EtOH (3/15, 20%) was higher than that of the group treated with AFB1 alone (0/14, 0%). Treatment with EtOH alone for 56 weeks did not induce either. These results indicate an enhancing effect of EtOH on AFB1‐induced hepatocarcinogenesis when it is given in the promotion phase.
Increased Tumor Control Rates in Murine Fibrosarcoma by Combined Therapy with L‐Alanosine and Radiation
Authors: Hong Seong Su , Alfieri Alan A. , Kim Sang Hie , Kim Jae Ho
Published: August 2005

L‐Alanosine, an analog of L‐aspartie acid, was investigated as one of a series of chemical compounds that may have inhibitory effects on the repair of potentially lethal damage caused by radiation using an in vivo murine fibrosarcoma (Meth‐A tumor) in BALB/cBy male mice. The combined treatment of single administration of L‐alanosine (600 mg/kg) and single dose of X‐irradiation (20 Gy) on Meth‐A tumors produced 62% tumor control, while the radiation alone resulted in less than 5% tumor control. The potentiating effect by L‐alanosine was higher when the drug was administered 8 h prior to X‐irradiation. The dose modification factor of the drug is estimated to be 1.4 for Meth‐A tumor. The increased tumor control rates with combined alanosine and radiation were highly dependent upon the time and sequence of the combined treatment. The reason for reduced efficacy at treatment times of less than 8 h prior to X‐irradiations appears to be related in part to the modulation of the body temperature by L‐alanosine when combined with Ketamine, an anesthetic agent.
Identification of a Human T Cell Clone with the Cytotoxic T Lymphocyte and Natural Killer‐like Cytotoxic Function against Autologous Mammary Carcinoma and K562 Line
Authors: Sato Takashi , Okubo Maraoru , Wada Yoshimasa , Sato Noriyuki , Kikuchi Kokichi
Published: August 2005

Pleural exudative lymphocytes (PLED from a 60‐year‐old female patient showed high cytotoxicity against the autologous mammary tumor line, HMC‐2, and NK‐susceptible K562 cells, although PLEL demonstrated only weak cytotoxic potentials against several allogeneic tumor lines. We successfully obtained seven cytotoxic T cell clones from PLEL bulk populations, and assessed the possibility that these lymphocytes are simply natural killer (NK)‐like cells or have the dual cytotoxic activity of cytotoxic T lymphocytes (CTL) and NK‐like cells. These clones, designated as TcHMC‐2, showed strong cytotoxicity against both HMC‐2 and K562 cells. In contrast, allogeneic human peripheral blood‐derived NK cells could not kill HMC‐2 targets. Furthermore, a blocking study of TcHMC‐2 cytotoxicity using monoclonal antibodies against CD3, CD8 and human MHC class I products showed that all of these antigen molecules were involved in the cytotoxicity of TcHMC.2 clone against autologous HMC‐2 cells, indicating MHC class I recognitive cytotoxicity. These data indicate that the TcHMC‐2 clone may have dual cytotoxicity with CTL‐ and NK‐like activity against autologous HMC‐2 mammary tumor and K562 cells, respectively.
Killing of Alveolar Macrophages and of Monocytes that Have Responded to Granulocyte‐Macrophage Colony‐stimulating Factor by Human Lymphokine‐activated Killer Cells
Authors: Sone Saburo , Inamura Noriaki , Singh Sukh Mahendra , Okubo Akio , Yanagawa Hiroaki , Nakanishi Mie , Ogura Takeshi
Published: August 2005

The susceptibilities of human blood monocytes and alveolar macrophages (AM) to cytotoxicity mediated by lymphokine (IL‐l)‐activated killer (LAK) cells were examined. Monocytes and AM of healthy donors were obtained by counter‐flow centrifugal elutriation (CCE) and bronclioalvcolar lavage, respectively. The LAK activity induced by incubation of blood mononuclear cells (MNC) for 4 days with recombinant interleukin 2 (IL‐2) was measured by a 4‐h 51Cr release assay. The LAK cells were not cytotoxic to freshly isolated monocytes, but were cytotoxic to autologous fresh AM and monocytes that had been incubated for more than 4 days in medium alone. Blood monocytes that had been incubated for 4‐ days in medium with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), macrophage colony‐stimulating factor (M‐CSF) or interleukin 3 (IL‐3) were much more susceptible than untreated monocytes to the cytotoxicity of LAK cells. When blood monocytes were separated by CCE into subpopulations of three sizes (small, medium and large), the medium‐ and large‐sized monocytes showed greater responses to GM‐CSF in terms of DNA synthesis and colony formation than the small‐sized cells. After treatment with GM‐CSF for 4 days, these medium and large monocytes were more susceptible than the small monocytes to the cytotoxic action of LAK cells. These results suggest that LAK cells may be important in situ in down‐regulating the functions of mature macrophages and blood monocytes that have responded to GM‐CSF.
Induction of Squamous Metaplasia, Dysplasia and Carcinoma in situ of the Mouse Tracheal Mucosa by Inhalation of Sodium Chloride Mist Following Subcutaneous Injection of 4‐Nitroquinoline 1‐Oxide
Authors: Karube Toshiaki , Katayama Hiroo , Takemoto Kazuo , Watanabe Shaw
Published: August 2005

Squamous metaplasia, dysplasia and carcinoma in situ (CIS) were induced in the ICR/Jcl mouse tracheal mucosa by exposure to a mist of 5% NaCl solution following single subcutaneous injection of 4‐nitroquinoline 1‐oxide (4‐NQO). Either subcutaneous injection of 4‐NQO or NaCl inhalation alone did not cause any marked change in the tracheal mucosa. The NaCl inhalation is considered to have promotion‐like action on the mouse tracheal mucosa after administration of 4‐NQO injection.
Inhibition of in vitro Tumor Cell Invasion by Transmethylation Inhibitors
Authors: Sbinkai Kiyoko , Mukai Mutsuko , Horai Takeshi , Ohigashi Hiroaki , Nishikawa Seiji , Inoue Hideo , Takeda Yoshiro , Akedo Hitoshi
Published: August 2005

Three inhibitors of S‐adenosylmethionine‐mediated transmethylation, 5′‐methylthioadenosine (MTA), 2′‐deoxyadenosine and sinefungin, inhibited in vitro invasion by a highly invasive clone (Cl‐30) of rat ascites hepatoma cells, AH 130 (AH cells). Difluoromethylthioadenosine (DFMTA), a non‐metabolizable derivative of MTA, also caused strong inhibition of invasion at concentrations that did not suppress the growth of the tumor cells. Cl‐30 cells precultured in methionine‐depleted medium showed decreased invasiveness. DFMTA was also effective on the invasion by fibrosarcoma, B16 melanoma and human lung carcinoma cell lines.
Smoking and Lung Cancer Mortality in Japanese Men: Estimates for Dose and Duration of Cigarette Smoking Based on the Japan Vital Statistics Data
Authors: Mizuno Shoichi , Akiba Suminori
Published: August 2005

For the purpose of understanding human carcinogenesis and making a quantitative prediction of lung cancer mortality in a general population of Japanese males, we evaluated a statistical model which assumes lung cancer mortality to be proportional to the 4.5th power of the effective duration of cigarette smoking among smokers and to the 4th power of age among nonsmokers, using Japan Vital Statistics data. For the male birth cohorts aged 30–69 in 1965 in the age range of 40–79, studied by quinquennial calendar time intervals from 1955 to 1985, it was found that, (i) for nonsmokers, the estimated lung cancer mortality rate was comparable to the rates reported in the US or Britain, assigning 20 to 25% proportions of nonsmokers, (ii) for smokers, the estimated duration of smoking was shorter than would be expected from the age when smoking was started according to various epidemiological surveys, and (iii) the estimated average numbers of cigarettes smoked per day by smokers were similar to those obtained by epidemiological studies, when these were estimated by incorporating a part of Doll and Peto's dose‐response relationship. Also discussed is the possibility of assessing lung cancer mortality risk for Japanese male smokers by means of the statistical model, a × (cigarettes smoked per day +β) × (age— (age started smoking) —γ)4,s.
Expression of Oncogenes during Rat Chemical Hepatotumorigenesis Promoted by Estrogen
Authors: Himeno Yasuo , Fukuda Yoshihiro , Hatanaka Masakazu , Imura Hiroo
Published: August 2005

To elucidate the role of oncogene expression in hepatocarcinogenesis, we examined the expression of 4 cellular oncogenes (c‐myc, c‐fos, Ha‐ras and c‐erbA) in liver tissues induced by chemical agents. Four groups of male Sprague‐Dawley rats were examined in the present study. Rats of the first and second groups were given a single intraperitoneal injection of diethylnitrosamine (DEN), 200 mg/kg body weight. Two weeks later, these rats were divided into two groups; the DEN‐C group received no further medication, whereas the DEN‐DES group was given diethylstilbestrol (DES), 0.5 mg/day, for 12 months. The DEN group was given DEN, 100 ppm, in drinking water for five months as the hepatocellular carcinoma (HCC) group. The DES group was given DES, 0.5 mg/day, from the start for 8 months. Rats of the DEN‐DES and DEN groups developed grossly visible hepatic tumors. Significantly higher levels of c‐myc gene expression were observed in tissues of HCC of the DEN group and in neoplastic nodules of the DEN‐DES groups than in the DES and DEN‐C group. The increase of c‐myc mRNA seemed to begin after 1 month of treatment and became significant at 4 months in the DEN‐DES group. On the other hand, no significant differences in mRNA levels of c‐fos, Ha‐ras and c‐erbA were observed among these four groups. Although the significance of increased c‐myc gene expression in neoplastic liver is still not known, it is conceivable that the persistent elevation of c‐myc gene expression in the DEN and DEN‐DES groups might contribute to the development of rat chemical hepatotumori genesis.
Tumor‐associated Expression of a Serum Protein, Termed αX Protein (α‐Inhibitor III), and Its mRNA in Rat Liver
Authors: Sugiyama Kenji , Izumi Susumu , Tomino Shiro , Nagase Sumi
Published: August 2005

A cDNA clone bearing the mRNA sequence for rat αX protein (αX) was isolated from a cDNA library constructed from rat liver mRNA. The nucleotide sequence of αX protein cDNA showed 97% homology with that of the 3′ ‐proximal domain of α1‐inhibitor III cDNA. The amino acid sequence deduced from that of αX cDNA also exhibited high homology with the primary sequences of α1‐inhibitor III and α2‐macroglobulin. K231 ascites hepatoma cells were transplanted into male ACI rats, and the level of αX mRNA in the liver of the tumor‐bearing rats was determined by RNA blot hybridization with the cDNA probe. The serum concentration of αX decreased to about 30% of the control value with time after transplantation. The amount of αX mRNA in the liver of tumor‐bearing rats was proportional to the serum concentration of αX. The serum concentrations of transferrin and albumin in the tumor‐bearing rats also decreased to about 30 and 60% of the normal levels, respectively. However, the amounts of mRNAs for transferrin and albumin in the liver of tumor‐bearing rats did not decrease. These findings indicate that the mechanisms of tumor‐associated decrease in the concentrations of different serum proteins In tumor‐bearing rats may differ.