bluuebunny/crossref_metadata_2025 huggingface dataset:
Augmenting Effect of a Nonmutagenic Fraction in Soy Sauce on Mutagenicity of 3‐Diazotyramine Produced in the Nitrite‐treated Sauce
Authors: Higashimoto Minoru , Matano Kagenori , Ohnishi Yoshinari
Published: August 2005

When 25 kinds of Japanese soy sauce at a concentration of 5% were incubated with 50m M sodium nitrite (pH 2) at 37° for 1 hr, the reaction mixtures induced 34‐834 (average 368 × 228) revertants per microliter of soy sauce equivalent in Salmonella typhimurium strain TA100 in the absence of S9 mix. The mutagen(s) formed was very unstable under natural daylight and a fluorescent lamp but quite stable under a yellow lamp as well as in the dark. In addition to the known precursors, i.e., tyramine and 1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid, 1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline, which caused weak mutagenesis, was found in the soy sauce. However, the sum of the activities of the three mutagen‐precursors after nitrite treatment accounted for only a part of the mutagenicity of nitrite‐treated soy sauce. There was in the soy sauce a factor which increased ninefold the mutagenicity of nitrite‐treated tyramine, 3‐diazotyramine. Therefore, tyramine was considered the principal precursor of the mutagen produced in the nitrite‐treated soy sauce. These three precursors together with the mutagenicity augmentation accounted for all the mutagenicity of nitrite‐treated sauce. The mutagenicity‐augmenting factor in the soy sauce was nonmutagenic before and after nitrite treatment and was stable to heat and light irradiation.
Mechanisms of Differential Strain Sensitivity in Gastric Carcinogenesis
Authors: Weisburger John H. , Jones R. Conrad , Barnes William S. , Pegg Anthony E.
Published: August 2005

The genetically‐controlled, distinct sensitivity of different rat strains to N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG)‐induced cancer of the glandular stomach and duodenum was investigated. MNNG is activated through thiols, and the thiol content of the glandular stomach, duodenum, and liver of the BN rat tended to be slightly, but not significantly higher than that of the Wistar, Sprague‐Dawley, Lewis, and Buffalo rats. The levels of the DNA repair system, O6‐alkylguanine transferase (AGT), in sensitive Wistar strain rats had values similar to those in resistant Buffalo strain rats. Administration of 80 mg/liter of MNNG in the drinking water for six weeks up to the time of tissue collection yielded the same AGT levels. Of all the parameters examined to account for genetically‐mediated sensitivity to gastrointestinal cancer induction, namely, N‐denitrosation, thiol activation, AGT‐related DNA repair, and cell duplication rates, the latter yielded the best association, although these factors acting together may be involved.
A Monoclonal Antibody, KM10 Reactive with Human Gastrointestinal Cancer and Its Application for Immunotherapy
Authors: Ohyanagi Harumasa , Ishida Hidefumi , Ishida Tsuneyuki , Soyama Nobuhiko , Yamamoto Masahiro , Okumura Shuichi , Kano Yoshiaki , Ueda Yasuo , Saitoh Yoichi
Published: August 2005

A monoclonal antibody, KM10 (IgG1) was produced by fusing spleen cells from a human gastric cancer cell (MKN45)‐primed BALB/c mouse with the murine myeloma cell line X63‐Ag8‐653. The antibody reacted strongly with the plasma membrane of human gastrointestinal carcinoma. Sections of the malignant and benign tissues were tested with immunoperoxidase. All of 10 (100%) large intestinal cancers, 26 of 31 (84%) gastric cancers, 5 of 7 (71%) pancreatic cancers and all of 3 (100%) ampullary cancers reacted positively. Moderate or weak reactivity was observed with normal human tissues, hepatoma and carcinomas of mammary, thyroid and adrenal glands. According to a study of the distribution of 125I‐labeled KM10 in nude mice bearing human gastric cancer, KM10 selectively localized in tumor tissue rather than normal tissue. Whole body autoradiography also supported such a selective distribution. Destruction of antigenic properties by pronase digestion demonstrated its protein nature and by Western blot analysis, it was identified as a protein with an Mr of 180–200 kd. KM10‐adriamycin (ADM) conjugate was prepared via an oxidized dextran bridge and this immunoconjugate retained the binding activity against human gastric cancer. MKN45 cells were inoculated subcutaneously into athymic mice and intravenous treatment was begun when the tumor became measurable. A dose‐dependent antitnmor activity was observed in vivo with KM10‐ADM conjugate, while this conjugate was less toxic than free ADM.
EFFECT OF CULTURE SUPERNATANT OF MT‐2 CELLS ON HUMAN IMMUNODEFICIENCY VIRUS‐PRODUCING CELLS, MOLT‐4/HIVHTLV‐IIIB CELLS
Authors: Matsuyama Toshifumi , Hamamoto Yoshiaki , Yoshida Tsutomu , Kido Yasuji , Kobayashi Susumu , Kobayashi Nobuyuki , Yamamoto Naoki
Published: August 2005

The effect of culture supernatant of MT‐2 cells on human immunodeficiency virus (HIV)‐producing cells, MOLT‐4/HIVHTLV‐IIIB cells, was examined. As compared to the effect on MOLT‐4 cells, parent cells not infected with HIV, a selective cytotoxic/cytostatic effect on MOLT‐4/ HIVHTLV‐IIIB cells was observed 4 days after treatment with up to 640‐fold‐diluted MT‐2 supernatant. Furthermore, under similar conditions, a 2‐ to 6‐fold increase in the number of HIV particles was detected in the culture of MOLT‐4/HIVHTLV‐IIIB cells 6 hr after treatment. Complete blocking of these effects by anti‐lymphotoxin monoclonal antibody, but not by anti‐tumor necrosis factor antibody, indicates that these effects of MT‐2 supernatant on MOLT‐4/HIVHTLV‐IIIB cells are attributable to a lymphotoxin‐related cytotoxic factor.
IMMOBILIZED DATURA STRAMONIUM AGGLUTININ COLUMN CHROMATOGRAPHY, A NOVEL METHOD TO DISCRIMINATE THE URINARY hCGs OF PATIENTS WITH INVASIVE MOLE AND CHORIOCARCINOMA FROM THOSE OF NORMAL PREGNANT WOMEN AND PATIENTS WITH HYDATIDIFORM MOLE
Authors: Endo Tamao , Iino Koichi , Nozawa Shiro , Iizuka Rihachi , Kobata Akira
Published: August 2005

Datura stramonium agglutinin (DSA) binds the asparagine‐linked sugar chains commonly found in the human chorionic gonadotropin (hCG) purified from urine of patients with invasive mole or choriocarcinoma, but not in that of normal pregnant women or patients with hydatidiform mole. With the use of an immobilized DSA column, a novel method to discriminate urinary hCGs from various trophoblastic diseases was developed.
Carcinogenesis by Nitrosohydroxyethylurea and Nitrosomethoxyethylurea in F344 Rats*1
Authors: Lijinsky William , Kovatch Robert M.
Published: August 2005

Nitroso ‐ 2 ‐ hydroxyethylurea and its methyl ether, nitroso ‐ 2 ‐ methoxyethylurea, were administered to male and female rats by gavage, each at two dose rates. The highest dose rate of nitrosohydroxyethylurea was 14 mg twice a week for 18 weeks, which led to death of all animals by week 34 with a variety of neoplasms, which have been observed in earlier experiments at lower doses, and included those in lung, colon, thyroid, forestomach, tongue, duodenum, jejunum, Zymbal's gland, thymus and mammary gland adenocarcinomas. At a dose 10 times smaller, the animals survived much longer, but the distribution of tumors was similar, except that there were few of the duodenum and jejunum. At an equimolar dose of nitrosomethoxyethylurea (1.6 mg, twice a week), the pattern of tumors was similar to that seen with nitrosohydroxyethylurea, including the absence of tumors in the duodenum and jejunum, although there were tumors of the colon. The rats treated with the methyl ether died earlier than those given nitrosohydroxyethylurea, indicating a greater potency of the former. At a dose of 3.2 mg twice a week, nitrosomethoxyethylurea produced the same pattern of tumors as the lower dose, but the animals died earlier. In all groups, there were more lung tumors in males than in females, and this was true to a lesser extent of the colon. The main effect of methylation of the hydroxyl group in nitrosohydroxyethylurea was to increase the potency of the carcinogen, but there was no effect on the target organ specificity of the nitrosourea.
Genotoxicity of a Variety of Hydrazine Derivatives in the Hepatocyte Primary Culture/DNA Repair Test Using Rat and Mouse Hepatocytes
Authors: Mori Hideki , Sugie Shigeyuki , Yoshime Naoki , Iwata Hitoshi , Nishikawa Akiyoshi , Matsukubo Kogen , Shimizu Hidesuke , Hirono Iwao
Published: August 2005

The genotoxicity of a variety of hydrazine derivatives was examined in the DNA‐repair test on rat or mouse hepatocytes. Out of 32 hydrazine derivatives, 6 chemicals, i.e., N‐acetyl‐4‐(hydroxymethyl)phenylhydrazine, 1,2‐dimethylhydrazine ‐ 2HCl, 1‐hydrazinophthalazine ‐ HCl, methylhydrazine‐sulfate, p, p′‐oxybisbenzene disulfonylhydrazide and phenylhydrazine‐HCl, elicited positive DNA repair responses in the test on rat hepatocytes. In the test on mouse hepatocytes, 4 more hydrazine derivatives, i.e., 1,1‐dimethylhydrazine, hydrazine hydrate, hydrazine sulfate and 2‐methyl‐4‐chlorophenoxyacetic acid hydrazide‐HCl also generated positive responses, in addition to the 6 positive compounds in the rat assay. These results suggest that mouse hepatocytes are more susceptible to the genotoxicity of hydrazine derivatives, and that the species differences in genotoxicity appear to he in agreement with the in vivo carcinogenicity of these agents.
Activated K‐ras in Tumorigenic and Non‐tumorigenic Cell Variants from a Rat Colon Adenocarcinoma, Induced by Dimethylhydrazine
Authors: Caignard Anne , Kitagawa Yoshinori , Sato Shigeaki , Nagao Minako
Published: August 2005

Using NIH3T3 cell transfection assay, activated c‐K‐ras was detected in two cell lines, TRb and TSb, obtained from a single colon adenocarcinoma induced in a rat by 1,2‐dimethylhydrazine. TRb cells give rise to progressive and metastatic tumors in the syngeneic rats, whereas TSb cells only induce regressive tumors. Levels of K‐ras transcripts in TRb and TSb cells were higher than that of NIH3T3 cells, but no difference was found between TRb and TSb cells. No significant difference was observed in expression levels of c‐myc in these two cell lines, c‐fos expression was, however, significantly lower in TRb than TSb cells.
LEVELS OF GLUTATHIONES TRANSFERASE π mRNA IN HUMAN LUNG CANCER CELL LINES CORRELATE WITH THE RESISTANCE TO CISPLATIN AND CARBOPLATIN
Authors: Nakagawa Kazuhiko , Yokota Jun , Wada Makio , Sasaki Yasutsuna , Fujiwara Yasuhiro , Sakai Masaharu , Muramatsu Masami , Terasaki Takeo , Tsunokawa Youko , Terada Masaaki , Saijo Nagahiro
Published: August 2005

The amounts of mRNA for glutathione S transferase π (GST π) were significantly lower in 3 human small cell lung cancer (SCLC) cell lines than in 3 non small cell lung cancer (NSCLC) cell lines. The sensitivities of the 3 SCLC cell lines to cisplatin and carboplatin were much higher than those of the 3 NSCLC cell lines. These results indicate that low levels of GST π mRNA expression in SCLC cell lines inversely correlate to high sensitivity to cisplatin and carboplatin, and further suggest that GST π may play an important role in intracellular inactivation of these drugs.
Generation and Characterization of Lymphokine‐activated Killer Cells against Fresh Human Leukemia Cells
Authors: Tahara Tohru , Iseki Rieko , Morishima Yasuo , Yokomaku Shozo , Ohno Ryuzo , Saito Hidehiko
Published: August 2005

Lymphokine‐activated killer (LAK) cells generated from 15 acute leukemia patients in remission showed significant levels of cytotoxicity against Daudi 1A4, a natural killer‐resistant cell line. This indicates that lymphocytes of leukemia patients in remission could respond to interleukin‐2 to generate conventional LAK cells. However, LAK cells caused lysis of autologous leukemia cells at considerably lower levels in seven out of the 15 patients, with the exception of one case (48.6% cytolysis). None of the remaining eight patients exhibited LAK activity against autologous leukemia cells. On the other hand, patients' LAK could lyse allogeneic leukemia cells including those resistant to autologous LAK. Thus, patients' LAK seem not to be defective in lysis of leukemia cells. In the cold target competition analysis, the binding of patients' LAK to leukemia cells could be inhibited by autologous and allogeneic leukemia cell competitors, implying that almost all leukemia cells could be recognized by patients' LAK. Most LAK cells from normal donors showed significant lysis of allogeneic leukemia cells, but some leukemia cells were found to be resistant to lysis. LAK cells against both leukemia cells and Daudi 1A4 were phenotypically heterogenous, and were predominantly observed in the T3− fraction in the precursor phase. In the effector phase, whereas LAK activity against leukemia cells was also predominantly shown in the T cell‐depleted fraction, similar levels of LAK activity against Daudi 1A4 were found in both the T cell‐depleted and ‐enriched fractions.
Prediction of the Gastric Cancer Mortality in 2000 in Japan
Authors: Watanabe Shaw , Tsugane Shoichiro , Ohno Yuhko
Published: August 2005

Gastric cancer mortality in Japan in the year 2000 has been predicted from sex‐ and age‐specific incidences and mortality trends and patient cure rates. The difference between the log‐linear decrease in incidence and the log‐quadratic decrease in mortality was considered to be the result of early diagnosis and treatment. Even on the assumption that 90% of patients could be cured in 2000, the number of deaths was estimated to be about 10,000. The decreasing incidence of cases brought about by birth cohort effects may contribute towards lowering the number of patients. The importance of health education in lowering the incidence of gastric cancer, by teaching people to keep up a sound life style, is discussed.
Pharmacokinetic Approach to Rational Therapeutic Doses for Human Tumor‐bearing Nude Mice
Authors: Inaba Makoto , Kobayashi Tomowo , Tashiro Tazuko , Sakurai Yoshio
Published: August 2005

To improve clinical predictability from therapeutic results of various antitnmor agents in human tumor/nude mouse models it seems to be important to use a dose pharmacokinetically equivalent to the clinical dose. Thus, we attempted to find the dose of a given drug that can reproduce in the nude mouse a plasma level similar to that seen in human patients treated with an effective dose of the drug based on comparative pharmacokinetic studies between man and nude mouse. As a result, those of 3 alkylating agents, mitomycin C, 3‐[(4‐amino‐2‐methyl‐5‐pyrimidinyl)methyl]‐l‐(2‐chloroethyl)‐l‐nitrosourea (ACNU) and cyclophosphamide, and those of 2 antimitotic agents, vincristine and vinblastine, were estimated to be one‐fourth or one‐fifth of their maximum tolerated doses (MTD's). On the other hand, in the case of adriamycin, its MTD was approxmately equivalent to its clinical dose pharmacokinetically. In contrast, clinically equivalent doses of 2 antimetabolites tested, 5‐fluorouracil and methotrexate, were significantly greater than their MTD's; i.e., their plasma levels did not reach the effective clinical ones even when their MTD's were administered to the nude mice. These results suggest that the antitumor effects of mostv antitumor agents are over‐ or underestimated in this model when MTD's are used as a therapeutic dose, and indicate that the use of clinically equivalent doses determined pharmacokinetically isdesirable.
Responsiveness of Human Gastric Tumors Implanted in Nude Mice to Clinically Equivalent Doses of Various Antitumor Agents
Authors: Inaba Makoto , Tashiro Tazuko , Kkobayashi Tomowo , Sakurai Yoshio , Maruo Koji , Ohnishi Yasuyuki , Ueyama Yoshito , Nomura Tatsuji
Published: August 2005

To reproduce clinical effects of various antitumor agents in the human tumor/nude mouse model, we investigated the responsiveness of 11 lines of human gastric tumor xenografts to doses of the agents pharmacokinetically equivalent to the respective clinical doses, which we designated the “rational dose” (RD). We found that the response rates to mitomycin C, 3‐[(4‐amino‐2‐methyl‐5‐pyrimidinyl]methyl‐1‐[2‐chloroethyl]‐1‐nitrosourea (ACNU), adriamycin, 5‐fluorouracil were 18%, and that to vinblastine was 30%; on the other hand, those to vincristine, methotrexate, and cyclophosphamide were poor. In contrast, in our previous study using the maximum tolerated doses, response rates to mitomycin C, ACNU, and vinblastine were as high as 64–82%, and those to adriamycin and 5‐fluorouracil were 18%. When these results were compared with the clinical response rates of gastric tumors, as a whole, the results with RD's exhibited much better coincidence with the clinical data in terms of relative therapeutic potency, indicating the validity of the use of clinically equivalent doses instead of maximum tolerated doses in the human tumor model.
Measurement by Leukocyte Adherence Inhibition of Autosensitization of Cancer Patients to Myelin Basic Protein
Authors: Gouda Zinab , Thomson David M. P.
Published: August 2005

In vitro cell‐mediated immunity was assayed by leukocyte adherence inhibition (LAI) to determine the extent of autosensitization to myelin basic protein (MBP). Leukocytes from 123 cancer patients, 16 patients freed of cancer, 135 patients with benign disease, and 26 patients with destruction of nervous parenchyma were tested. Most patients with cancer reacted to MBP: 92%, 93%, 82%, 78%, 75% and 62% for pancreatic, colonic, esophageal, lung, ovarian and breast. Few patients with benign diseases reacted to MBP. Patients with multiple sclerosis (MS) were sensitized to MBP, but patients with other nervous tissue injury did not react to MBP. Cancer patients did not remain sensitized to MBP once they were freed of their cancer. The LAI assay is a straightforward method of measuring cellular autosensitivity to MBP. In the population of patients tested, autosensitivity to MBP was confined, except for MS, principally to cancer patients.
AMPLIFIED ALLELE OF THE HUMAN N‐myc ONCOGENE IN NEUROBLASTOMAS
Authors: Yamada Masao , Kurosawa Hidemitsu , Nakagawa Yuichi , Nakagome Yasuo , Tsuda Tohru , Higashi Ken
Published: August 2005

The N‐myc amplification unit was investigated using two restriction fragment length polymorphisms for SphI and PvuII which we previously found to occur in the 2nd intron and in the 3’region of the human N‐myc oncogene, respectively. All the three haplotypes which are dominant in the Japanese population were observed in the amplified DNA after analyses of a total of 22 DNA samples of fresh neuroblastomas with N‐myc amplification. We conclude that only one of the alleles was amplified and that either allele could be amplified with respect to both the SphI and PvuII polymorphisms.
NO CORRELATION BETWEEN L‐myc RESTRICTION FRAGMENT LENGTH POLYMORPHISM AND MALIGNANCY OF HUMAN COLORECTAL CANCERS
Authors: Ikeda Isuzu , Ishizakz Yukihito , Ochiai Masako , Sakai Ryuichi , Itabashi Masayuki , Onda Masahiko , Sugimura Takashi , Nagao Minako
Published: August 2005

The correlations of the restriction fragment length polymorphism (RFLP) pattern of L‐myc with the progressive state of cancer and metastases to lymph nodes or other organs were examined in 35 cases of human colorectal cancer by χ2 analysis. No significant correlation was found.
A SYNTHETIC SINGLE‐STRANDED DNA, POLY(dG, dC), INDUCES TNTERFERON‐α/β AND ‐γ, AUGMENTS NATURAL KILLER ACTIVITY, AND SUPPRESSES TUMOR GROWTH
Authors: Tokunaga Tohru , Yamamoto Saburo , Namba Kenji
Published: August 2005

When various synthetic double‐ or single‐stranded DNAs were incubated with spleen cells from mice (BALB/c or CDF1) at 37° for 20 hr, it was found that some of the DNAs augmented NK activity and produced factors in the culture supernatants which showed antiviral activity and activity to render mouse macrophages cytotoxic toward tumor cells. Poly(dG, dC) showed the strongest activities, when incubated with spleen cells from lipopolysaccharide‐nonresponsive mice, C3H/HeJ. The activity of the culture supernatant to activate macrophages was completely abolished by a small amount of anti‐IFNγ antibody. On the other hand, the virus‐inhibitory activity of the supernatant was mostly neutralized by anti‐IFNα/β. When IMC tumor cells (5 × 105 cells) were mixed with poly(dG, dC) (100 μg) and then inoculated intradermally into CDF1 mice, the tumor did not take, while tumors grew progressively and killed the mice in a control group inoculated with tumor cells alone. Direct cytotoxicity of poly(dG, dC) at a concentration of 1,000 μg/ml against IMC cells was not observed in vitro.
Carcinogenic Potency of N‐Nitrosomethyl(2‐hydroxypropyl)amine and Other Metabolic Relatives of N‐Nitrosobis(2‐hydroxypropyl)amine by Single Intraperitoneal Injection on the Lung of Rats
Authors: Yokose Yoshihiko , Yamamoto Kazuhiko , Nakajima Akira , Eimoto Hiroyuki , Maruyama Hiroshi , Mori Yukio , Konishi Yoichi
Published: August 2005

The carcinogenic effects of a single intraperitoneal injection of N‐nitrosobis(2‐hydroxypropyl)‐amine (BHP) or its metabolic relatives, N‐nitrosomethyl(2‐hydroxypropyl)amine (MHP), N‐nitrosobis(2‐oxopropyl)amine (BOP), N‐nitroso(2‐hydroxypropyl)(2‐oxopropyl)amine (HPOP) and N‐nitroso‐2,6‐dimethylmorpholine (NDMM), were studied in male Wistar rats. The main target organ of these nitrosamines proved to be the lung, followed by the thyroid. Lung lesions were induced in a dose‐dependent manner with total lung tumor incidences reaching 55% to 100%. BHP, MHP, HPOP and NDMM all caused lung carcinomas to develop (22% to 44% incidence), whereas BOP was only associated with adenomas. On the basis of dose administered and incidence of carcinomas, MHP appeared to be the most potent lung carcinogen of the five nitrosamines investigated. Smaller numbers of neoplasms were also induced in the kidney, urinary bladder, esophagus and intestine at differing rates by these nitrosamines.
Establishment of Megakaryoblastic Cell Lines by Coinfection of Abelson Murine Leukemia Virus and Recombinant SV40‐retrovirus
Authors: Kajigaya Sachiko , Suda Toshio , Suda Junko , Eguchi Mitsuoki , Moroi Masaaki , Sudo Tetsuo , Saito Masaki , Miira Yasusada
Published: August 2005

Murine embryonic cells including yolk sac prepared from 8‐day embryos were co‐infected with Abelson murine leukemia virus (A‐MuLV) and/or a recombinant retrovirus containing large T and small t antigens, and early region of simian virus 40 (M‐SV40). By coinfection with A‐MuLV and M‐SV40, megakaryoblastic cells were obtained in addition to mast cells and fibroblastic cells. However, following infection with A‐MuLV or M‐SV40 alone, no megakaryoblastic cells were detected, although mast cells and/or fibroblastic cells developed. The same results were obtained in several experiments. By single‐cell transfer, 6 acetyl‐cholinesterase (AchE)‐positive clonal cell lines were established. Characteristics of megakaryocytes, such as AchE, glycoproteins lIb and IlIa, and platelet peroxidase were detected in two representative cells (C1 and C8). More significant changes expressing differentiation were observed following treatment with phorbol myristate acetate or pokeweed mitogen‐stimulated murine spleen cell conditioned medium, although release of platelets was not observed. This is the first report showing development of megakaryocytic cells as the result of coinfection with retroviruses.
Properties of Mouse Melanoma Antigen and Its Secretion Mechanism from the Cell Surface
Authors: Kuwabara Ichiro , Tagawa Masatoshi , Harada Yoshitada , Ito Toshihiro , Taniguchi Masaru
Published: August 2005

We analyzed the biochemical properties and biological significance of the melanoma antigen secreted in the culture supernatants of B16 melanoma cells. The 80 kilodalton (kd) molecule bearing the epitopes of mouse melanoma antigen was found to associate noncovalently with an 18 kd moiety in the culture supernatants as well as on the cell surface. Tunicamycin treatment of B16 cells did not affect the expression of the 69 kd nonglycosylated form of the 80 kd molecule but did abolish the association between the two molecules on the cell surface. We could not detect this antigen as a soluble form when the N‐linked glycosylation was inhibited. Therefore, the glycosylation of the 80 kd molecule is essential for the formation of the 80 kd/18 kd complex and also for the secretion. Moreover, the affinity‐purified melanoma antigen from the supernatants could induce anti‐melanoma suppressor cells which block the generation of cytotoxic T lymphocytes against melanoma cells. Thus, the 80 kd glycoprotein as a soluble melanoma antigen performed a pivotal function in the escape mechanisms of melanoma cells from the host immune surveillance system.
Presence of Aberrant Transcripts of ret Proto‐oncogene in a Human Papillary Thyroid Carcinoma Cell Line
Authors: Ishizaka Yukihito , Itoh Fumio , Tahira Tomoko , Ikeda Isuzu , Ogura Tsutomu , Sugimura Takashi , Nagao Minako
Published: August 2005

In a papillary thyroid carcinoma cell line, TPC‐1, we found transcripts hybridizing to ret proto‐oncogene (proto‐ret) cDNA probes. The transcripts hybridized to the probes encoding the kinase domain but not to those of the transmembrane and extracellular domains of proto‐ret The sizes of the main transcripts in TPC‐1 were aberrant, being 2.0, 2.5, 4.0 and 5.0 kb. In the neuroblastoma cell lines, the transcripts were 3.9, 4.5, 6.0 and 7.0 kb, which have been proved to be generated by alternative splicing and polyadenylation from the non‐altered protto‐ret oncogene. All of the four transcripts in TPC‐1 are about 2 kb smaller than the corresponding ones in the neuroblastoma. From the length of the transcripts, it is suspected that the transcripts in TPC‐1 are a rearranged form of proto‐ret. This is the first report describing the aberrant transcripts of proto‐ret in a human tumor.
Lung Cancer Risk Comparison among Male Smokers between the “Six‐prefecture Cohort” in Japan and the British Physicians' Cohort
Authors: Mizuno Shoichi , Akiba Suminori , Hirayama Takeshi
Published: August 2005

We estimated the effective duration of cigarette smoking using the data of lung cancer mortality among male smokers of a large‐scale cohort study in Japan and evaluated its role in the lung cancer risk difference between male smokers of the Japanese cohort and the British physicians' cohort. By selecting male cohort members who answered that they had started smoking at ages 18–22 (average = 20.3), the subjects of our analysis, which numbered 49,013, were made relatively homogeneous in terms of age at which smoking was started. Assuming lung cancer mortality to be proportional to the 4.5th power of the effective duration of cigarette smoking, i.e., (age—θ)4,5, as was proposed on the basis of the British cohort study by Doll and Peto, the parameter θ was estimated to be 29.4 for male smokers aged 40–64 in 1966; therefore, the estimated duration of cigarette smoking was, on average, 9.1 years (95% confidence interval=5.8–11.6) shorter than that calculated from the reported age at which smoking was started. Our findings suggested that the low lung cancer mortality relative to daily cigarette consumption in Japan resulted from the shorter duration of cigarette smoking in the Japanese cohort, possibly due to the severe shortage of cigarettes during and shortly after World War II. Once the effective duration of cigarette smoking was adjusted, lung cancer mortality in the range of 5–34 cigarettes per day was fairly comparable to that observed among the cohort of male British physicians.
Association of Elevated Expression of the c‐erbB‐2 Protein with Spread of Breast Cancer
Authors: Yamada Yukinori , Yoshimoto Masataka , Murayama Yoichi , Ebuchi Masakazu , Mori Shigeo , Yamamoto Tadashi , Sugano Haruo , Toyoshima Kumao
Published: August 2005

We analyzed amplification and expression of the c‐erbB‐2 gene in human breast cancers. Southern blot hybridization analysis demonstrated amplification of the c‐erbB‐2 gene in 10 out of 50 tumor DNAs examined. The degree of amplification was three‐ to twenty‐fold relative to normal placenta. The c‐erbB‐2 protein could be analyzed in 39 tumor tissues of the 50 samples by immune‐blotting, and elevated expression of the c‐erbB‐2 protein was found in 15 cases. On the other hand, expression of the c‐erbB‐2 products was not detected in normal breast tissues either by immuno‐blotting or by immuno‐histological analysis. These data indicate that transcriptional and/or translational activation of c‐erbB‐2 might occur in some breast cancers in addition to activation by gene amplification. The elevated expression of the C‐erbB‐2 protein was most strongly correlated with lymph‐node metastasis (P< 0.001), suggesting that c‐erbB‐2 expression is involved in promotion of the lymph‐node metastasis of human breast cancers. Therefore, immuno‐histological diagnosis with anti‐c‐erbB‐2 antibody might be useful as an indicator to predict lymph‐node involvement in breast cancer.
Kinetic Evaluation of 11C‐1‐Aminocyclopentane Carboxylic Acid in Rabbits Bearing VX‐2 Tumors Using Positron Emission Tomography
Authors: Fujiwara Takehiko , Matsuzawa Taiju , Kawai Hiroaki , Kawashima Ryuta , Itoh Masatoshi , Watanuki Syoichi , Takahashi Toshihiro , Iwata Ren , Ido Tatsuo
Published: August 2005

Tumor detection with 11C‐1‐aminocyclopentane carboxylic acid (11‐ACPC) showed that this amino acid has a high affinity for malignant tumors. We studied the kinetics of intravenously injected 11C‐ACPC in the rabbit VX‐2 tumor using positron emission tomography. Three female rabbits bearing VX‐2 tumor in the thighs were used. High uptake of 11C‐ACPC was seen in the tumor and liver. 11‐ACPC in plasma decreased rapidly after injection and its activity in the tumor increased with time. The kinetic evaluation of ACPC uptake into the tumor was performed using the unidirectional transport model. The average values of the transfer constant of 11C‐ACPC for VX‐2 tumor were 0.030±0.002 ml/min/g. This preliminary result may form the basis for a quantitative analysis of the in vivo distribution of 11C‐labeled ACPC in tumors.
High Risk of Mother‐to‐Child Transmission of HTLV‐I in p40tax Antibody‐positive Mothers
Authors: Sawada Takashi , Tohmatsu Junichi , Obara Takashi , Koide Atsushi , Kamihira Shimeru , Ichimaru Michito , Kashiwagi Seizaburo , Kajiyama Wataru , Matsumura Nobuyuki , Kinoshita Kenichiro , Yano Michitami , Yamaguchi Kazunari , Kiyokawa Tetsuyuki , Takatsuki Kiyoshi , Taguchi Hirokuni , Miyoshi Isao
Published: August 2005

A new enzyme‐linked immunosorbent assay (ELISA) for detecting the antibody to a human T‐lymphotropic virus type I (HTLV‐I) tax gene product, p40tax, has been developed. By this ELISA method, we have investigated the relationship between the presence of p40tax antibody in HTLV‐I‐infected mothers and the virus transmission rate from mothers to their children. The rate of mother‐to‐child transmission of HTLV‐I was higher in P40tax antibody‐positive mothers than in antibody‐negative ones. Thus, the presence of P40tax antibody may indicate an increased risk of vertical transmission of HTLV‐I.
Expression of Cytokine mRNA in Leukemic Cells from Adult T Cell Leukemia Patients
Authors: Kodaka Taiichi , Uchiyama Takashi , Umadome Hiroshi , Uchino Haruto
Published: August 2005

HTLV‐I infection of peripheral mature T cells appears to induce the expression of cellular genes including those of some cytokines and their receptors. We examined the expression of interleukin‐lα (IL‐lα), IL‐lβ, IL‐2, IL‐3, IL‐4 and granulocyte/macrophage colony‐stimulating factor (GM‐CSF) at the mRNA level in fresh leukemic cells from 20 adult T cell leukemia patients to see whether there is any association between cytokine expression and MTLV‐I expression and between their expression and clinical manifestations such as hypercalcemia or neutrophilia. IL‐lα, IL‐Iβ and IL‐3 expression was observed in 3, 7 and 1 of 20 cases examined, respectively. However, there seemed to be no association between IL‐1 expression and clinical manifestations. IL‐2, IL‐4 and GM‐CSF mRNA expression was not detected. HTLV‐I viral RNA expression was detected only in one case in which IL‐3 mRNA was expressed in both peripheral blood and lymph node cells and a relatively high proportion of leukemic cells expressed IL‐2 receptor (p55, Tac). Thus, in the present study we could not find any correlation between cytokine expression and HTLV‐I expression in peripheral blood fresh leukemic cells except in one unusual case.
A Human Monoclonal Antibody Recognizing a Surface Antigen on Stomach Cancer Cells
Authors: Yoshikawa Kazuhiro , Furukawa Koichi , Ueda Ryuzo , Iwasa Susumu , Lloyd Kenneth O. , Notake Kunihiro , Takahashi Toshitada
Published: August 2005

Lymph‐node lymphocytes of a patient with stomach cancer were fused with the mouse‐human heterohybridoma, HM‐S. A clonc (2F9) was isolated that showed stable production of an IgM antibody reactive with NUGC‐4 stomach cancer cell line. This antibody reacted predominantly with a cell surface antigen on cell lines originating from gastro‐intestinal cancer and adenocarcinoma of lung, whereas it was not generally reactive with other types of cancers, or with normal kidney cells or fibroblasts. Biotin‐labeled 2F9 antibody clearly stained cell smears and the nude mouse tumor of NUGC‐4, hut it did not show a positive reaction with stomach cancer tissues obtained from more than 10 patients, indicating that the antigen detected is very weakly expressed on tumor cells or on a limited number of stomach cancers. The antigen shed from NUGC‐4 cell line was detected in the culture supernatant. 2F9 antibody precipitated a glycoprotein with a molecular weight of over 200 kilodaltons as well as a possible glycolipid, from NUGC‐4 cells labeled with [3H]glucosamine or [35S]‐H2SO4. Periodic acid treatment of the tissue section decreased reactivity with 2F9 antibody, but heat, neuraminidase or protease treatment did not. These results suggested that the epitope is present on a carbohydrate moiety not containing sialic acid, and that a part of the antigen molecule is sulfated.
Changes in Lymphocyte Subsets Following Multiple Administration of Recombinant Interleukin‐2 plus Recombinant Interferon‐beta or ‐gamma in Tumor‐bearing Mice
Authors: Iigo Masaaki , Nishikata Ken‐ichi , Nakajima Yoko , Moriyama Masami
Published: August 2005

Treatment with a combination of recombinant human interleukin‐2 (rHIL‐2) and recombinant mouse interferon‐beta (rIFN‐β) or ‐gamma (rIFN‐γ) showed a significant antitumor effect against sc adenocarcinoma 755 in mice, although treatment with either one alone had almost no effect. The combination of rHIL‐2 and rIFN‐β caused regression of the tumor but the combination of rHIL‐2 and rIFN‐γ did not. Injection of tumor‐bearing mice with the combinations of rHIL‐2 and rIFN resulted in marked increases in the total number of peritoneal lymphocytes, and the frequency of Lyt‐2+ cells was more markedly increased by the combination of rHIL‐2 and rIFN‐β than by the combination of rHIL‐2 and rIFN‐γ. In Winn assay, elimination of the Lyt‐2+ population abolished the protective capacity of the peritoneal cells. The subsets of thymocytes were drastically changed when mice were bearing a tumor or were treated with cytokines. In particular, Lyt‐2+/L3T4+ cells were decreased in tumor‐bearing mice, but many Lyt‐2+/L3T4+ cells were maintained in the thymus by treatment with a cytokine alone. When treated with rHIL‐2 and rIFN‐β the Lyt‐2+/L3T4+ cells were markedly decreased, while Lyt‐2‐/L3T4‐ T‐cells were increased, but these subsets were little changed by treatment with rHIL‐2 plus rIFN‐γ. Thus, injections of rHIL‐2 and rIFN‐β into tumor‐bearing mice resulted in a high frequency of Lyt‐2+/L3T4‐ cells in the peritoneal cavity, together with changes in the T‐cell subsets in the thymus. These results suggest that maturation of T‐cells in the thymus may be an important step in the pathway by which cytokine treatment brings about regression of tumors.
Enhancement of Therapeutic Effect of Interleukin‐2 on Spontaneous Pulmonary Metastases of Lewis Lung Carcinoma by Killer Helper Factor Associated with Increased Induction of Killer Activity
Authors: Fukuta Katsuyuki , Sone Saburo , Kitahara Misa , Okada Masaji , Ogura Takeshi
Published: August 2005

Killer helper factor (KHF) was previously found to be produced by a human T cell hybridoma, 24A CA2. We studied the therapeutic effects of interleukin‐2 (IL‐2) and KHF on the inhibition of pulmonary mctastascs of syngeneic Lewis lung carcinoma (3LL) in C57BL/6N mice. Multiple subcutaneous (sc) injections of IL‐2 plus KHF had significantly more effect than injections of IL‐2 alone in inhibiting spontaneous pulmonary mctastascs and prolonging survival of the mice. The effect of KHF with IL‐2 on induction of lymphokine(IL‐2)‐activated killer (LAK) activity against P‐29 cells was examined in the murine system. Spleen cells generated LAK activity after incubation for 4 days with more than 500 U/ml of IL‐2. In contrast, KHF alone did not render spleen cells cytotoxic. The combination of these lymphokines at subthreshold concentrations, however, resulted in significant in vitro induction of LAK activity. The LAK activity of splenocytes incubated with IL‐2 plus KHF was maximal after 4 days, and persisted for longer than that of cells treated with IL‐2 alone. The LAK cells induced by KHF plus IL‐2 were also cytotoxic to FBL and YAC‐1 cells. Moreover, spleen cells of mice bearing lung metastases could be induced to the cytotoxic state by sc injections of IL‐2 plus KHF. These results indicate that combination treatment with IL‐2 and the new lymphokine KHF should he useful clinically in inducing LAK activity for inhibition of pulmonary metastases.
Antitumor Effect of Interleukin‐1β in the Double Grafted Tumor System
Authors: Ebina Takusaburo , Ishikawa Keiko
Published: August 2005

The antimetastatic effect of recombinant human interleukin‐1β (rIL‐1β) in a new experimental mouse model was studied. Intratumoral administration of IL‐1β strongly inhibited the growth of Meth‐A solid tumors in male BALB/c mice and led to a complete regression of tumors and resistance to reinoculated tumor. Subsequently, the anti‐metastatic effect of IL‐1β was examined in the double grafted tumor system, in which mice first received simultaneous intradermal inoculations of Meth‐A in both right (106 cells) and left (2×105 cells) flanks and were then injected with 0.2 μg of IL‐1β in the right tumor on days 3, 4 and 5. IL‐1β significantly inhibited the growth of the left, non‐treated tumor. When mice received only an inoculation of Meth‐A (2×105 cells) in the left flank and were injected subcutaneously with IL‐1β into the right flank on day 3 (single tumor system), there was no inhibition of the growth of the left, non‐treated tumor. These findings suggest that intratumoral IL‐1β immunotherapy in one region has an effect on tumor growth in another region. Immunized spleen cells were taken from mice which had been cured by the intratumoral administration of IL‐1β. Adoptive transfer of the immunized spleen cells caused the complete regression of Meth‐A tumors. These results suggest that intratumoral administration of IL‐1β might induce cytotoxic cells in the left non‐treated tumor of the double grafted tumor system and bring about the regression of metastatic tumors. On the other hand, recombinant tumor necrosis factor was effective only on the treated, right tumor, having no effect on the distant, left tumor in the double grafted tumor system. Recombinant interleukin‐2 was effective on neither the right tumor nor the left tumor in this system. These results show that there are major differences of antitumor mechanism among cytokines.
Inhibition of Multidrug‐resistant Human Tumor Growth in Athymic Mice by Anti‐P‐glycoprotein Monoclonal Antibodies
Authors: Tsuruo Takashi , Hamada Hirofumi , Sato Shigeo , Heike Yuji
Published: August 2005

In an effort to devise an effective treatment for human drug‐resistant cancers, we have developed monoclonal antibodies, MRK16 and 17, reactive to the multidrug transporter protein, P‐glycoprotein. The monoclonal antibodies given intravenously effectively prevented tumor development in athymic mice inoculated subcutaneously with drug‐resistant human ovarian cancer cells 2780AD. Treatment with MRK16 induced rapid regression of established subcutaneous tumors and apparent cures of some animals. Complement‐dependent cytotoxicity (MRK16) and antibody‐dependent cell‐mediated cytolysis (MRK16 and 17) were observed with these antibodies. These monoclonal antibodies may have potential as treatment tools against multidrug resistant human tumors possessing the P‐glycoprotein.
Antitumor Activity of ME2303, a Fluorine‐containing Anthracycline, against Human Tumors Implanted in Nude Mice
Authors: Tsuruo Takashi , Sato Shigeo , Yusa Keisuke
Published: August 2005

A fluorine‐containing anthracyctine, ME2303, given intravenously once a week for 4 weeks at the maximum tolerated dose showed better therapeutic effects against 2 gastric, 3 lung and 2 human breast tumor xenografts than did adriamycin (ADM) at the maximum tolerated dose. Among the tumors, ME2303 showed a better effect against St‐40, a well‐differentiated human gastric adenocarcinoma, against which ADM showed only a marginal effect. Likewise, ME2303 was more effective against Lu‐24 human small cell carcinoma and MX‐1 human medullary tubular adenocarcinoma than ADM. Notably, the Lu‐24 tumor, developed in nude mice, disappeared after the treatment in 3 out of 6 mice. ME2303 would be an interesting compound for phase I and II clinical studies in the future
bcl‐2 Gene Rearrangement Analysis in Japanese B Cell Lymphoma; Novel bcl‐2 Recombination with Immimoglobulin K Chain Gene
Authors: Osada Hirotaka , Seto Masao , Ueda Ryuzo , Emi Nobuhiko , Takagi Norio , Obata Yuichi , Suchi Taizan , Takahashi Toshitada
Published: August 2005

The rearrangement of bcl‐2 gene was studied in 56 Japanese B cell lymphoma cases to investigate the contribution of bcl‐2 gene to lyraphomagenesis in Japan. Ten out of 56 cases showed bcl‐2 gene rearrangement; it was detected in only 5 out of 16 follicular lymphoma cases (31%) and in 5 out of 40 diffuse B cell lymphoma cases (13%). The incidence of bcl‐2 gene involvement in Japanese follicular lymphomas was lower than those reported in the United States. This might contribute to the lower incidence of follicular lymphoma cases in Japan. Novel recombination between bcl‐2 and Ig K genes at the 5′ region of bcl‐2 and Jg4 segment was observed in one follicular lymphoma case, suggesting that bcl‐2 gene is transcriptionally activated by Ig K enhancer. It was also suggested that this case had originated from a more differentiated B cell than most follicular lymphomas with bcl‐2‐Ig H recombination.
Similarity in the Effect of Caffeine on DNA Synthesis after UV Irradiation between Xeroderma Pigmentosum Variant Cells and Mouse Cells
Authors: Yagi Takashi , Takebe Hiraku
Published: August 2005

The effect of UV irradiation on the rate of DNA synthesis was compared among normal human, xeroderma pigmentosum (XP, group A and variant) and mouse cells with and without caffeine in the culture medium after UV irradiation. At the same levels of survival, approximately 37%, all cells showed reduction in the rate of synthesis 0–3 h after UV irradiation followed by a recovery to normal or near‐normal level 12 h later. In the presence of caffeine, no change in the recovery patterns was observed in normal human and XP A cells. XP variant cells and mouse cells showed little or no recovery in the presence of caffeine even after 12 h, when full recovery was obtained without caffeine. XP variant and mouse cells appear to have a common response in that post‐irradiation treatment with caffeine inhibits reinitiation of UV‐reduced DNA replication. Enhancement by caffeine of UV‐killing in XP variant and mouse cells may he due to the retarded resumption of DNA replication.
Tumor Cells Treated with Vaccinia Virus Can Activate the Alternative Pathway of Mouse Complement
Authors: Wakamiya Nobutaka , Okada Noriko , Wang Yu‐Lan , Ito Tetsuya , Ueda Shigeharu , Kato Shiro , Okada Hidechika
Published: August 2005

Vaccinia virus has been shown to render mouse tumor cells highly immunogenic. Since we have demonstrated that induction of complement activating capacity on guinea pig tumor cells by Sendai virus infection causes the tumor cells to become immunogenic, we assumed that vaccinia virus infection of mouse tumor cells might render them reactive with homologous mouse complement. Therefore, murine tumor cells, MH134 and X5563, infected with vaccinia virus (VV) were incubated with mouse plasma and C3 deposition was determined by staining with fluorescein isothiocyanate‐labeled anti‐C3. We found that VV‐infected tumor cells possess the ability to activate the alternative complement pathway (ACP) of murine complement. For induction of complement activating ability, at least a 3 h incubation of the infected MH134 cells was required indicating that the generation of ACP‐activating capacity on MH134 infected with VV is time‐dependent. Furthermore, ultraviolet‐irradiated vaccinia virus was able to induce ACP‐activating capacity on tumor cells as well.
Evaluation of the Human T‐Cell Leukemia Virus Type I Seropositivity of Blood Donors by the Particle Agglutination Inhibition Test
Authors: Kwon Kil‐Won , Ikeda Hisami , Yano Misako , Sekiguchi Sadayoshi
Published: August 2005

In the HTLV‐I seroscreening of blood donor sera by gelatin particle agglutination (PA), more than 50% (55.6%) of the PA‐positive sera were negative by immunofluorescence assay (IF). However, when donors were divided into age groups, there were increasing numbers of IF‐positive/PA‐positive donors with age. Among the PA‐positive donors in the 50–64 age group, 65.9% were IF‐positive compared to 16.0% in the 16–19 age group. The serological specificities of the IF‐negative/ PA‐positive specimens were tested by using a newly developed PA inhibition (PAD test. The HTLV‐I specificity of the PAI test was confirmed by the observation that agglutinations with anti‐HTLV‐I p19 and gp21 monoclonal antibodies as well as IF‐positive sera were specifically inhibited with HTLV‐I preparations or HTLV‐I‐positive cell extracts and not with HTLV‐I‐negative cell extracts. Sixty of the 104 specimens collected randomly from the IF‐negative/PA‐positive donors were PAI‐positive. The majority (80%) of such PAI‐positive sera showed more than two bands of HTLV‐I gag‐encoded polypeptide, p19, p24, p2S and p53 on Western blotting. Some of the PAI‐positive sera were also positive by enzyme immunoassay. These results indicate that at least some of the IF‐negative/ PA‐positive donors possess HTLV‐I‐specific antibody and may be potential HTLV‐I carriers who will become IF‐positive at a later age
Inhibition of Tumor Cell Invasion by Ubenimex (Bestatin) in vitro
Authors: Saiki Ikuo , Murata Jun , Watanabe Kunihito , Fujii Hideji , Abe Fuminori , Azuma Ichiro
Published: August 2005

We have investigated the effect of the immunomodulator ubenimex (bestatin) on tumor cell invasion of reconstituted basement membrane (Matrigel). The invasion of B16‐BL6 melanoma cells and Lewis lung carcinoma (3LL) cells into Matrigel‐coated filters was inhibited by the presence of bestatin in a concentration‐dependent manner. The prctrcatment of either tumor cells or Matrigel with bestatin, however, had little effect on the invasion of tumor cells. Since bestatin was found to inhibit aminopeptidase in addition to its immunomodulating activities, the inhibition of tumor invasion by bestatin is likely to be associated with the action as an enzyme inhibitor. Other aminopeptidase inhibitors, arphamcnine B and amastatin A, could also inhibit tumor cell invasion into Matrigel. Bestatin inhibited hydrolyzing activities towards substrates of aminopeptidases in B16‐BL6 melanoma cells. However, bestatin did not have any effect on the haptotactic migration and adhesion of tumor cells to the substrates. These results indicated that bestatin may inhibit tumor cell invasion through a mechanism involving its inhibitory action on aminopeptidases in tumor cells.