bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro Targeting and Cytotoxicity of Adriamycin in Liposomes Bearing Monoclonal Antibody against Rat or Human gp125 Cell Proliferation‐associated Antigen
Authors: Tanaka Toshiyuki , Suzuki Shinya , Masuko Takashi , Hashimoto Yoshiyuki
Published: August 2005

Chemoimmunoliposomes (CIL) were prepared by entrapping adriamycin in monoclonal antibody (mAb)‐coated liposomes and examined for their binding capacity and cytotoxicity to relevant target tumor cells. Sonicated unilamellar liposomes were coated with B3 and HBJ127 mouse, mAbs, which recognize a rat and a homologous human cell proliferation‐associated surface antigen, gp125, respectively, and then adriamycin was entrapped in the liposomes by means of transmembrane Na±/K±gradients using valinomycin. These CIL selectively bound with relevant target tumor cells bearing the corresponding gp125 antigen, such as BC47 rat bladder cancer, FTL‐13 rat thymic lymphoma, T24 human bladder cancer and Molt‐4 human leukemia cells, although the binding capacities of the CIL to bladder cancer cells were relatively larger than those to lymphoma cells in both rat and human systems. This difference in the target cell binding was found to be attributable to the amount of gp125 antigen expressed on each target tumor cell, as determined by a Scatchard plot analysis. In accordance with the target cell binding capacities of CIL preparations, the CIL displayed much higher cytotoxic activity to bladder cancers than to lymphomas in both rat and human systems. In conjuction with our previous finding that gp125 antigen is expressed on tumor cells but not on resting normal cells, these findings indicate that CIL composed of anti‐gp125 mAb will be useful for tumor therapy and that the antitumor efficacy is dependent upon the extent of the antigen expression on target tumor cells.
High Induction of Poly(ADP‐ribose) Polymerase Activity in Bleomycin‐resistant HeLa Cells
Authors: Urade Masahiro , Sugi Masakazu , Mima Takashi , Ogura Takafumi , Matsuya Tokuzo
Published: August 2005

Poly(ADP‐ribose) polymerase activity was measured in bleomycin (BLM) ‐ resistant HeLa (HeLa‐BLMr) and the parental HeLa cells after BLM treatment. HeLa‐BLMr cells, which had been subcultured in growth medium containing 1 μg/ml of BLM, showed a 3.75‐fold higher enzyme activity than did HeLa cells, but this activity was decreased to the same level as that of HeLa cells after 48 h of BLM‐free cultivation. When HeLa and HeLa‐BLMr cells after a 48‐h cultivation in BLM‐free growth medium were treated with BLM, the enzyme activity was induced at a higher level (2.5–3.8 times) in HeLa‐BLMr than in HeLa cells and was inhibited markedly in HeLa‐BLMr and slightly in HeLa cells by nicotinamide, an inhibitor of this enzyme. The BLM‐induced cell killing by nicotinamide was highly potentiated (about 18 times) in HeLa‐BLMr as compared to HeLa cells.
Carcinogenicity of 2‐Amino‐3‐methylimidazo[4,5‐f]quinoline in Nonhuman Primates: Induction of Tumors in Three Macaques
Authors: Adamson Richard H. , Thorgeirsson Unnur P. , Snyderwine Elizabeth G. , Thorgeirsson Snorri S. , Reeves Jeanette , Dalgard Dan W. , Takayama Shozo , Sugimura Takashi
Published: August 2005

The carcinogenic potential of 2‐amino‐3‐methylimidazo[4,5f]quinoline (IQ) was evaluated in cynomolgus monkeys. Monkeys received IQ, beginning at the age of one year, at doses of 10 or 20 mg/kg by gavage. Thus far, IQ has induced hepatocellular carcinoma in three monkeys with a latent period of 27 to 37 months. Metastases to the lung occurred in two of the three monkeys. Microscopically, the hepatocellular carcinoma in all three cases demonstrated a trabecular pattern. These data demonstrate that IQ is a potent carcinogen in nonhuman primates and support the idea that it is a potential carcinogen for humans.
Effects of Growth Factors and Hormones on Growth and Morphological Differentiation of Human Breast Epithelial Cells within Collagen Gel in Serum‐free Medium
Authors: Takahashi Kazuhide , Kawahara Satoru , Ono Tetsuo
Published: August 2005

When human epithelial cells that had grown out from either carcinoma or histologically non‐malignant breast tissues were seeded within type I collagen gels in serum‐free medium, they successively grew and protruded many radial duct‐like extensions with lumina. Separate deletion of each of the supplements from the medium showed that growth as well as morphological differentiation of carcinoma‐derived cells were prevented in the absence of epidermal growth factor (EGF) or hydrocortisone. Removal of insulin or ethanolamine plus phosphoethanolamine caused a significant inhibition of cell growth without interfering with the morphological differentiation. Contrary to the case with carcinoma‐derived cells, both growth and morphological differentiation of epithelial cells derived from non‐malignant breast tissues were prevented when EGF, hydrocortisone or insulin was absent. Removal of each of the other supplements (except for transferrin), including ethanolamine plus phosphoethanolamine, prolactin, or prostaglandin, caused a significant inhibition of cell growth with no apparent inhibition of morphological differentiation. The present results suggest that human epithelial cells derived from either carcinoma or histologically non‐malignant breast tissues strongly depend on the presence of EGF and hydrocortisone and there is a decreased dependence on insulin in carcinoma‐derived cells with respect to their growth and morphological differentiation during culture within collagen gels.
Changes in Serum and Tissue Carcinoembryonic Antigen with Growth of a Human Gastric Cancer Xenograft in Nude Mice
Authors: Kiyama Teruo , Onda Masahiko , Tokunaga Akira , Nishi Keigo , Mizutani Takashi , Yoshiyuki Toshiro , Shimizu Yasuhito , Matsukura Norio , Tanaka Noritake , Asano Goro
Published: August 2005

We established a human gastric cancer xenograft which, when inoculated into nude mice, showed a positive correlation between tumor growth and the serum level of carcinoembryonic antigen (CEA). Serum CEA levels in the mice rose continuously with increasing tumor weight after inoculation, showing a correlation coefficient of 0.96. A positive correlation was also observed between the tissue CEA level and tumor weight, the former increasing along with the latter. Furthermore, the level of serum CEA closely paralleled that of tissue CEA. The serum CEA level fell after tumor extirpation, with a half‐life of approximately 86 h. These results suggest that the elevation of serum CEA is attributable to the gain in tumor weight as well as the increase of CEA production in the tumor tissue. Thus, human gastric cancer xenografts in nude mice are a good model for examining the biological role of CEA.
Methotrexate Cytotoxicity as Related to Irreversible S Phase Arrest in Mouse L1210 Leukemia Cells
Authors: Tsurusawa Masahito , Niwa Makoto , Katano Naoyuki , Fujimoto Takeo
Published: August 2005

The association between cytotoxicity and cell cycle perturbation caused by methotrexate (MTX) was investigated in mouse L1210 leukemia cells by flow cytometric bromodeoxyuridine/DNA assay. In the range of concentrations of MTX from 10‐7M to 10‐6M, in vitro exposure to the drug for 6 h caused a dose‐dependent suppression of clonal growth of the tumor cells and S phase arrest in the cycle progression, resulting in an accumulation of cells in early S phase, in which they showed no definite increase of DNA content above G1 levels. The surviving fraction of the clonogenic cells corresponded with the fraction of cells which recovered from the S phase arrest in MTX‐free medium. In mice bearing L1210 ascites tumors, a bolus injection of MTX caused the S phase arrest of the tumor cells as shown in suspension cultures, and cytokinetic recovery was observed in parallel with the regrowth of the tumor. These results showed that irreversible S phase arrest is a critical cytokinetic event associated with the cytotoxicity of MTX.
Transition of Antibody to Hepatitis C Virus from Chronic Hepatitis to Hepatocellular Carcinoma
Authors: Kiyosawa Kendo , Tanaka Eiji , Sodeyama Takeshi , Furuta Kiyoshi , Usuda Seiichi , Yousuf Muhammad , Furuta Seiichi
Published: August 2005

Fifty‐eight patients with chronic hepatitis C were followed for more than 7 years. Of them, 10 patients were found to develop hepatocellular carcinoma, 14 to develop liver cirrhosis, 30 to sustain chronic hepatitis, and 4 to show subsidence of hepatitis. Antibody to hepatitis C virus (anti‐HCV) disappeared from the 4 patients whose hepatitis subsided, but it persisted in the remaining 54 patients. The mean titer of anti‐HCV was almost the same at the stages of chronic hepatitis and of cancer in the 10 patients who developed hepatocellular carcinoma. These results indicate that chronic infection of hepatitis C virus may lead to hepatocellular carcinoma.
Inhibition of abl Oncogene Tyrosine Kinase Induces Erythroid Differentiation of Human Myelogenous Leukemia K562 Cells
Authors: Honma Yoshio , Okabe‐Kado Junko , Kasukabe Takashi , Hozumi Motoo , Umezawa Kazuo
Published: August 2005

The human chronic myelogenous leukemia cell line K562 expresses a structurally altered c‐abl protein with tyrosine kinase activity. Erythroid differentiation of K562 cells was induced by tyrosine kinase inhibitors, but not by other kinase inhibitors. Treatment of K562 cells with 5'd(TACTGGCCGCTG‐AAGGGC)3′, complementary to the second exon (codons 2 to 7) of c‐abl mRNA, inhibited cell growth and induced benzidine‐positive cells in a dose‐dependent manner. However, exposure to the sense oligomer did not induce erythroid differentiation of the cells. These results suggest that inhibition of abl tyrosine kinase activity is closely related to induction of erythroid differentiation of K562 cells. A multidrug‐resistant subline (K562R) was induced to undergo erythroid differentiation by tyrosine kinase inhibitors such as genistein or herbimycin A as effectively as the parent K562 cells were. Therefore, tyrosine kinase inhibitors might be useful as cancer chemotherapeutic agents against some multidrug‐resistant leukemias having abnormally high activity of oncogene tyrosine kinase(s).
Subcutaneous Administration of Recombinant Human Granulocyte Colony‐stimulating Factor (KRN8601) in Intensive Chemotherapy for Patients with Advanced Lung Cancer
Authors: Eguchi Kenji , Shinkai Tetsu , Sasaki Yasutsuna , Tamura Tomohide , Ohe Yuichiro , Nakagawa Kazuhiko , Fukuda Masaaki , Yamada Kouzou , Kojima Akira , Oshita Fumihiro , Morita Masashige , Suemasu Keiichi , Saijo Nagahiro
Published: August 2005

The efficacy and toxicity of recombinant human granulocyte colony‐stimulating factor (rh G‐CSF, KRN8601) given subcutaneously was evaluated in patients with advanced lung cancer undergoing intensive chemotherapy. Twenty‐nine and 30 patients with or without prior therapy were enrolled in this study. At dose levels of 50, 90 and 130 μg/m2 of rh G‐CSF for 14 consecutive days after chemotherapy, the mean neutrophil nadir counts, the mean neutrophil nadir ratios and the duration of neutropenia (days of < 1000/mm3) were significantly improved. No significant differences were seen in frequency and duration of febrile episodes (>38°C). When rh G‐CSF is given subcutaneously, the dose required for an equal effect in alleviating neutropenia is 50% of that required when it is given intravenously. The monocyte counts in the peripheral blood were also significantly increased after chemotherapy cycles with rh G‐CSF. The cumulative plasma concentration of rh G‐CSF showed a decrement after 7–9 days despite maintenance of the same dose of rh G‐CSF for the entire 14 days. In conclusion, 50–130 μg/m2 of sc rh G‐CSF increased the neutrophil nadir count and shortened the duration of neutropenia in patients undergoing intensive chemotherapy for lung cancer without intolerable side effects.
A Case‐Control Study of Male Colorectal Cancer in Aichi Prefecture, Japan: with Special Reference to Occupational Activity Level, Drinking Habits and Family History
Authors: Kato Ikuko , Tominaga Suketami , Ikari Akira
Published: August 2005

The relationships of occupational activity level, drinking habits and family history of cancer to the risk of male colorectal cancer by subsites were investigated in a case‐control study involving 1,716 cases with colon cancer, 1,611 cases with rectal cancer and 16,600 controls with other sites of cancer identified from the Aichi Cancer Registry, Japan 1979–1987. An occupation with a low activity level was associated with an increased risk of colorectal cancer; the age‐adjusted relative risk (RR) compared to the high activity level group was 1.92 (95% confidence interval (CI): 1.38–2.67) for proximal colon cancer, 1.52 (95% CI: 1.19–1.94) for distal colon cancer and 1.38 (95% CI: 1.17–1.62) for rectal cancer. Beer drinkers showed an increased risk of colorectal cancer; the age‐adjusted RR was 1.49 (95% CI: 1.13–1.95) for proximal colon cancer, 1.65 (95% CI: 1.34‐2.04) for distal colon cancer and 1.88 (95% CI: 1.62–2.18) for rectal cancer. The RR for family history of colorectal cancer was 3.40 (95% CI: 2.19–5.29) for proximal colon cancer, 2.54 (95% CI: 1.73–3.75) for distal colon cancer and 1.78 (95% CI: 1.28–2.49) for rectal cancer. Multivariate analysis controlled for age, residence, marital status and smoking in addition to occupational activity level, beer drinking and family history of colorectal cancer did not materially change the RRs. When these three variables were combined, the RR was 15.72 (95% CI: 5.40–45.78) for proximal colon cancer, 10.55 (95% CI: 4.24–26.27) for distal colon cancer and 6.69 (95% CI: 3.12–14.36) for rectal cancer.
Chromosome Abnormalities of Gastric Cancer Detected in Cancerous Effusions
Authors: Misawa Shinichi , Horiike Shigeo , Taniwaki Masafumi , Tsuda Shoichiro , Okuda Tsukasa , Kashima Kei , Abe Tatsuo , Sugihara Hiroyuki , Noriki Sakon , Fukuda Masaru
Published: August 2005

The chromosomes were examined in cancerous effusions obtained from 7 patients with gastric cancer. In 1 patient, the modal chromosome number was 46 with a normal chromosome complement in the majority of the cells examined. The other 6 patients revealed numerical and structural aberrations. Among the structural rearrangements detected, chromosome 3 was involved in the short arm and in the long arm, each in three patients; bands p25, q21, q23, and q27 were recurrently involved and a band q23 was lost in 3 patients. Rearrangements of chromosome 5 in the long arm and of chromosome 17 at or near the centromere were also observed in three patients each. Gains of chromosome 7 was seen in 5 patients and of chromosome 13 in 4. Some of these alterations may be specific for gastric cancer.
Stomach Carcinogenicity of Caffeic Acid, Sesamol and Catechol in Rats and Mice
Authors: Hirose Masao , Fukushima Shoji , Shirai Tomoyuki , Hasegawa Ryohei , Kato Toshio , Tanaka Hikaru , Asakawa Emiko , Ito Nobuyuki
Published: August 2005

The carcinogenic potential of caffeic acid, sesamol and catechol was examined in male and female F344 rats and B6C3F1 mice, groups of 30 animals being treated with diets containing 2% caffeic acid, 2% sesamol or 0.8% catechol for 104 weeks (rats) or 96 weeks (mice). Histological examination revealed that caffeic acid induced forestomach squamous cell carcinoma in 57% (P<0.001 vs. controls) and 50% (P<0.001) of male and female rats, respectively, whereas sesamol was associated with squamous cell carcinoma at incidences of 31% (P<0.001) in male rats, and 38% (P<0.001) and 17% (P<0.05) in male and female mice, respectively. Catechol induced glandular stomach adenocarcinomas in 54% (P<0.001) and 43% (P<0.001) of male and female rats, respectively. The results thus clearly demonstrated that all three antioxidants are carcinogenic in rodent stomach epithelia.
Modulation of c‐myc Expression by Transforming Growth Factor β1 in Human Hepatoma Cell Lines
Authors: Ito Nobuyuki , Kawata Sumio , Tamura Shinji , Takaishi Kenji , Saitoh Ryuzo , Tarui Seiichiro
Published: August 2005

The effects of transforming growth factor β1 (TGF‐β1) on cell proliferation of human hepatoma cell lines, PLC/PRF/5 and Mahlavu, were investigated under serum‐free conditions. DNA synthesis was strongly inhibited in the PLC/PRF/5 cells by addition of TGF‐β1 (0.5 to 4.0 ng/ml), but remained unchanged in the Mahlavu cells. Also the expression of c‐myc mRNA was suppressed by the addition of TGF‐β1 in the PLC/PRF/5 cells but not in the Mahlavu cells. These results indicate that TGF‐β1 might regulate cell growth, in part, by modulating c‐myc expression, although there is no direct proof that c‐myc expression is really relevant to DNA synthesis mediated by TGF‐β1.
Chemo‐radioresistance of Small Cell Lung Cancer Cell Lines Derived from Untreated Primary Tumors Obtained by Diagnostic Bronchofiberscopy
Authors: Tanio Yoshiro , Watanabe Masatoshi , Inoue Tamotsu , Kawase Ichiro , Shirasaka Takuma , Ikeda Toshiyuki , Hara Hideki , Masuno Tomiya , Saito Shin'ichi , Kawano Kiyoshi , Kitamura Hajime , Kubota Kaoru , Kodama Nagahisa , Kawahara Masaaki , Sakatani Mitsunori , Furuse Kiyoyuki , Yamamoto Satoru , Kishimoto Susumu
Published: August 2005

New cell lines of small cell lung cancer (SCLC) were established from specimens of untreated primary tumors biopsied by diagnostic bronchofiberscopy. The advantage of this method was ease of obtaining specimens from lung tumors. Establishment of cell lines was successful with 4 of 13 specimens (30%). Clinical responses of the tumors showed considerable variation, but were well correlated with the in vitro sensitivity of the respective cell lines to chemotherapeutic drugs and irradiation. One of the cell lines was resistant to all drugs tested and irradiation, while another was sensitive to all of them. Although the acquired resistance of SCLC is the biggest problem in treatment, the natural resistance to therapy is another significant problem. Either acquired or natural, resistance mechanisms of SCLC may be elucidated by the use of such cell lines derived from untreated tumors. This method and these SCLC cell lines are expected to be useful for the serial study of biologic and genetic changes of untreated and pre‐treated tumors, or primary and secondary tumors.
Detection of Provirus in an HTLV‐II Producer CD8+ T Cell Line by Polymerase Chain Reaction Combined with Digoxigenin‐ELISA Method
Authors: Miyamoto Kanji , Tomita Noriko , Ohtsuki Yuji , Kitajima Ko‐ichi
Published: August 2005

A human T‐cell leukemia virus type II (HTLV‐II) producer cell line, designated HTLV‐IIA, was established by cocultivation with leukocytes from an anti‐human T‐cell leukemia type I (HTLV‐I) antibody‐positive white male intravenous drug abuser and a healthy Japanese female. The cell line was examined for viral antigens by the indirect immunofluorescence method. The cytoplasm of over 80% of the cells was brilliantly stained. Cytogenetically, the cell line has a normal female karyotype. Electron microscopy of the HTLV‐IIA disclosed many C‐type retrovirus particles of mature, immature and non‐cored types in the extracellular spaces. The surface markers of the transformed cells are CD2+, CD3+, CD4– and CD8+. To distinguish between HTLV‐I and HTLV‐II infection in the cell line, a method for detection of the HTLV‐II provirus was developed by combining the polymerase chain reaction method with digoxigenin‐enzyme‐linked immunosorbent assay method.
Selective Induction of Prostate Carcinomas in F344 Rats Treated with Intraperitoneal Injections of N‐Hydroxy‐3,2′‐dimethyl‐4‐aminobiphenyl
Authors: Shirai Tomoyuki , Nakamura Atsushi , Fukushima Shoji , Wang Ching Y. , Yamada Hideyuki , Ito Nobuyuki
Published: August 2005

Groups of F344 and Wistar rats were given an intraperitoneal injection of N‐hydroxy‐3,2′‐dimethyl‐4‐aminobiphenyl (N‐OH‐DMAB) at a dose of 5 mg/kg body weight with a 1‐week dietary pretreatment with ethinyl estradiol (EE), and this regimen was repeated 10 times at one‐week intervals. Additional groups were given N‐OH‐DMAB 10 times without the dietary EE pretreatment. The total experimental period was 60 weeks. Carcinomas and atypical hyperplasias of the prostate developed in 8 (42%) and 16 (84%) of 19 F344 rats without the dietary EE treatment and in 1 (6%) and 7 (39%) of 18 rats with the EE diet, respectively. No prostatic tumors were found in Wistar rats, although atypical hyperplasias were observed in 6 of 18 rats with and 4 of 8 rats without the EE supplementation. Tumor yields in other organs were extremely low, resulting in good survival of the animals. A comparison of the results with those obtained for DMAB suggests that intraperitoneal administration of N‐OH‐DMAB in F344 provides a better induction method for models of prostate carcinogenesis.
Immunohistochemical Study on Overexpression of c‐erbB‐2 Protein in Human Breast Cancer: Its Correlation with Gene Amplification and Long‐term Survival of Patients
Authors: Tsuda Hitoshi , Hirohashi Setsuo , Shimosato Yukio , Tanaka Yuko , Hirota Teruyuki , Tsugane Shoichiro , Shiraishi Masato , Toyoshima Kumao , Yamamoto Tadashi , Terada Masaaki , Sugimura Takashi
Published: August 2005

Using a polyclonal antibody monospecific to the c‐erbB‐2 oncogene product, an immunohistochemical study on the expression of c‐erbB‐2 protein was performed in formalin‐fixed, paraffin‐embedded tissue sections from 176 primary breast carcinomas in which amplification of the c‐erbB‐2 gene had been detected in 28 cases. Expression of the c‐erbB‐2 protein was detected in 44 cases (25%), being strongly positive in 27 (15%) and weakly positive in 17 (10%). All cases with amplification of c‐erbB‐2 showed positive staining of its protein. There were only four cases in which c‐erbB‐2 was strongly expressed without amplification of the gene. In the group showing strongly positive staining, both overall and disease‐free survival were significantly poorer than in the remainder of the cases. Using Cox's regression model analysis, overexpression of c‐erbB‐2 protein was demonstrated to be an effective prognostic factor independent of nodal status or tumor size.
Oligoclonal Immunoglobulin Gene Rearrangements in Philadelphia Chromosome‐positive Common Acute Lymphoblastic Leukemia
Authors: Ikeda Takeshi , Kita Kenkichi , Kawakami Keiki , Ohno Toshiyuki , Seki Shigeki , Nasu Kaori , Ueda Takanori , Honjo Tasuku , Shirakawa Shigeru
Published: August 2005

The occurrence of more than two rearranged bands of immunoglobulin heavy chain (IgH) genes in B precursor acute lymphoblastic leukemia (ALL) has recently been documented. To elucidate the nature of such leukemias, we studied 30 patients with common ALL, including 6 patients with Philadelphia chromosome (Ph1)‐positive ALL, by immunophenotyping and genotyping. In 10 of the 30, Southern blotting showed oligoclonal patterns of IgH gene arrangements, which were frequently detected in Ph1‐positive ALL. In one patient of the 10, three rearranged bands of Ig k chain genes were detected. Ph1 abnormality and co‐expression of myeloid associated antigens were found in 5 and 5 of the 10, respectively. Detection of multiple fragments of IgH genes would be suggestive of multipotent progenitor origin of these ALL.
Tumor Necrosis Factor Changes Sensitivity of Differentiation of Mouse Leukemia M1 Cells by Lipopolysaccharide
Authors: Nakaya Kazuyasu , Deguchi Yoshiko , Arata Satoru , Kasai Nobuhiko , Nakamura Yasuharu
Published: August 2005

A clone of mouse leukemia M1 cells was induced to differentiate by lipopolysaccharide (LPS) (LPS‐sensitive clone) while another clone of the same cells was resistant (LPS‐resistant clone). LPS and lipid A preparations from Pseudomonas diminuta and Pseudomonas vesicularis were as active as Escherichia coli LPS in the induction of differentiation of the LPS‐sensitive clone. Synthetic lipid A precursor Ia (compound 406), which has no interleukin 1 (IL‐1)‐inducing activity toward monocytes, had strong differentiation‐inducing activity toward the LPS‐sensitive clone. The combined treatment of the LPS‐sensitive clone with LPS and recombinant tumor necrosis factor (rTNF) did not further increase the degree of differentiation induced by LPS alone. By contrast, the LPS‐resistant clone was markedly induced to differentiate by LPS in the presence of rTNF. Combined treatment of the LPS‐resistant clone with LPS and other cytokines such as recombinant IL‐1α, recombinant granulocyte colony‐stimulating factor, and interferon‐γ was not effective in inducing marked synergistic differentiation. These results raise the possibility that rTNF changes the sensitivity of M1 cells to induction of differentiation by LPS.
Antitumor Activity of Host T and Non‐T Cells Recovered from Tumor Nodules after Interferon Therapy
Authors: Honjo Kaoru , Suhara Yasuji , Kataoka Tateshi
Published: August 2005

We examined the modification of host T cells of tumor nodules by interferon (IFN) therapy in mouse models. The host cells were recovered from regressing tumor nodules of mice at Day 13 after intradermal tumor inoculation at Day 0 and administration of 5 × 105 U/mouse/day IFN at Day 6 to Day 10. These host cells neutralized in vivo Meth A growth in a dose‐dependent fashion. In vitro treatment of these cells with anti‐Thy 1.2 monoclonal antibody and rabbit sera as a source of complement abrogated their tumor‐neutralizing activity, but only partially, indicating that both T cells and non‐T cells were involved in tumor neutralization. The finding that host cells from regressing tumor nodules of either Meth A or Meth 1, an antigenically distinct fibrosarcoma, neutralized both Meth A and Meth 1 tumors without much selectivity was consistent with possible non‐T cell involvement. Most of these characteristics of host cells of regressing nodules of IFN‐administered mice were also noted with host cells of progressing nodules of placebo‐administered mice and there was no significant difference in neutralizing activity qualitatively or quantitatively between the two sources of host cells. There was no significant difference in host T and B cell numbers and compositions of regressing and progressing nodules either. These essentially negative findings raise the possibility, among others, that the primary target host cells to be modified by IFN were not T cells, although the therapeutic effect of IFN was dependent on the host T cells.
Combination Treatment with Irritant and Recombinant Interleukin 2 in the Peritoneal Cavity for Evoking Effective Anti‐tumor Activity: Generation of Lymphokine‐activated Killer Cells and Tumor‐specific Killer Cells
Authors: Uchida Hiroyuki , Taniguchi Kazuto , Nomoto Kikuo
Published: August 2005

Meth A sarcoma, growing in the subcutaneous tissue of syngeneic BALB/c mice, regressed completely after an intraperitoneal (ip) injection of protease peptone (PP) (on day 6) followed by 2 ip administrations (on days 7 and 8) of human recombinant interleukin‐2 (IL‐2, 25 μg/day), whereas one such treatment alone had little effect on the tumor growth. While this combination treatment was effective in anti‐asialo GM1 antibody‐treated mice, no such effect was noted in T cell‐depleted ATXFL (thymectomized, irradiated and fetal liver cell‐reconstituted) mice. These results show that T cells are mainly responsible for this antitumor effect. Treatment with a combination of PP and IL‐2, but not with either PP or IL‐2 alone, resulted in a marked increase in the T cell population in the peritoneal cavity after the treatment. At an early stage after the combination treatment, both peritoneal exudate cells (PEC) and spleen cells exhibited killing activity with a promiscuous specificity. However, at a later stage, 7 days after the treatment, Meth A‐specific killer activity was observed in both PEC and the spleen. Meth A rechallenge was rejected by the mice in which the tumor had regressed, but the antigenically different Meth 1 was accepted by them. A similar result was obtained in Winn's neutralization test. These results suggest that this combination treatment, which is effective in the generation of lymphokine‐activated killer cells in the peritoneal cavity, finally resulted in the induction of tumor‐specific killer cells in the periphery. These results clearly show the anti‐tumor efficacy of combination treatment with PP and rIL‐2.
Optimal Treatment Regimens for 5′‐Deoxy‐5‐fluorouridine, with or without (E)‐5‐(2‐Bromovinyl)‐2′‐deoxyuridine, against Various Tumors in Mice
Authors: Iigo Masaaki , Miwa Masanori , De Clercq Erik
Published: August 2005

The antitumor activity of 5′‐deoxy‐5‐fluorouridine (DFUR), a prodrug of 5‐fluorouracil (5‐FU), is markedly enhanced if DFUR treatment is combined with (E)‐5‐(2‐bromovinyl)‐2′‐deoxyuridine (BVDU). Combined oral administration of DFUR (10 mg/kg) and BVDU (10 mg/kg) three times (every 3 h) per day for 5 days afforded greater antitumor activity than a single dose of DFUR (300 mg/kg/day) for 5 days in mice bearing either adenocarcinoma 755 or Lewis lung carcinoma, while in the colon 26 system the antitumor effects of both treatment regimens were equivalent. Thus, a low‐dose regimen of DFUR when combined with BVDU provides a similar or greater antitumor activity than a high‐dose regimen of DFUR that is not combined with BVDU. The area under the curve of plasma 5‐FU following a treatment with the combination of DFUR (10 mg/kg) and BVDU (10 mg/kg) was equal to that following DFUR (300 mg/kg) treatment.
Epidermal Growth Factor Prolongs Survival Time of Tumor‐bearing Mice
Authors: Amagase Harunobu , Tamura Kouichi , Okuhira Masayasu , Kakimoto Masanori , Amano Hirotaka , Hashimoto Ken , Fuwa Tohru , Tsukagoshi Shigeru
Published: August 2005

We observed that human epidermal growth factor (hEGF) alone prolonged the survival time of mice bearing various murine syngeneic tumors as well as athymic nude mice bearing human xenografts. No changes in the subcutaneous solid tumor mass volume were observed. Prolongation of survival time by hEGF was observed in mice bearing murine epidermoid carcinoma (BSC) and human gastric carcinoma (KATO III), but not in murine epidermoid carcinoma (KLN205) or human epidermoid carcinoma (A431). Human tumor cells such as A431, KATO III, and murine tumor cells, KLN205, BSC had roughly 2 × 106, 3 × 104, 1.3 × 103 and 1 × 103 EGF receptors/cell, respectively. Although KLN205 and BSC tumor cells maintained nearly the same number of EGF receptors, the effects of hEGF were very different. Although A431 tumor cells had nearly 100 times more receptors than KATO III cells, the prolongation of survival time of mice bearing A431 by hEGF was no better than that of mice bearing KATO III. Accordingly, it appears that this prolongation of survival time by hEGF is independent of the number of EGF receptors on tumor cells. In addition, hEGF was shown to inhibit experimental pulmonary metastasis of murine BSC tumor, but was ineffective with murine KLN205 tumor. These results suggest that prolongation of survival time by hEGF may result from the inhibition of tumor cell metastasis and EGF may play a role in preventing the metastasis of certain malignant neoplasms unrelated to its effects through the EGF receptor on tumor cells.
Determinants of Drug Response in a Cisplatin‐resistant Human Lung Cancer Cell Line
Authors: Fujiwara Yasuhiro , Sugimoto Yoshikazu , Kasahara Kazuo , Bungo Masami , Yamakido Michio , Tew Kenneth D. , Saijo Nagahiro
Published: August 2005

To elucidate the mechanism(s) of cisplatin resistance, we have characterized a human non‐small cell lung cancer cell line (PC‐9/CDDP) selected from the wild type (PC‐9) for acquired resistance to cisplatin. PC‐9/CDDP demonstrated 28‐fold resistance to cisplatin, with cross resistance to other chemotherapeutic drugs including chlorambucil (× 6.3), melphalan (× 3.7) and 3‐[(4‐amino‐2‐methyl‐5‐pyrimidinyl)]methyl‐1‐(2‐chloroethyl)‐1‐nitrosourea (ACNU) (× 3.9). There was no expression of mdr‐1 mRNA in either wild‐type or resistant cells. The mRNA and protein levels of glutathione S‐transferase (GST) × were similar in the two lines. A GST‐μ isozyme was present in equal amounts and the activities of selenium‐dependent and independent glutathione peroxidase and glutathione reductase were unchanged. The mRNA level of human metallothionein IIA and the total intracellular metallothionein levels were reduced in the resistant cells. Significantly increased intracellular glutathione (GSH) levels were found in the resistant cells (20.0 vs. 63.5 nmol/mg protein) and manipulation of these levels with buthionine sulfoximine produced a partial sensitization to either cisplatin or chlorambucil. Increased GSH probably also played a role in determining cadmium chloride resistance of the PC‐9/CDDP, even though this cell line had a reduced metallothionein level. Also contributing to the cisplatin resistance phenotype was a reduced intracellular level of platinum in the PC‐9/CDDP. Thus, at least two distinct mechanisms have been selected in the resistant cells which confer the phenotype and allow degrees of cross resistance to other electrophilic drugs.
New Antitumor Platinum(II) Complexes with Both Lipophilicity and Water Miscibility
Authors: Maeda Mitsuaki , Takasuka Nobuo , Suga Tetsuya , Sasaki Takuma
Published: August 2005

Water‐miscible platinum(II) complexes with 1,2‐diaminocyclohexane as the carrier ligand and bile acids as the leaving ligands were synthesized and tested for antitumor activity against intra‐peritoneally implanted leukemia L1210 cells in mice. These complexes were water‐miscible after appropriate sonication due to the presence of hydrophilic hydroxyl groups in the molecule, even though the complexes were essentially lipophilic. The complexes had high antitumor activity, but their optimal dose levels differed, and the administration route and form affected the antitumor activity. More lipophilic complexes showed higher activity when administered with Lipiodol than in water suspension, while the hydrophilic complexes showed significant activity when administered in water suspension. Intravenous administration of DACHP(cheno)2in water suspension resulted in potent antitumor activity, while other complexes showed moderate activity via this route.
A Case‐Control Study of Gallstones: A Major Risk Factor for Biliary Tract Cancer
Authors: Kato Ikuko , Kato Kiyoshi , Akai Sadahiko , Tominaga Suketami
Published: August 2005

Because of the strong association between gallstones and biliary tract cancer, we conducted a case‐control study of gallstones at Niigata Cancer Center Hospital. Eighty‐six cases with gallstones (33 males and 53 females) and 116 hospital controls (56 males and 60 females) were surveyed by means of a self‐administered questionnaire. Gallstones were categorized into cholesterol stones (25 cases) and pigment stones (30 cases) based on the appearance of the stones. In multivariate analyses based on an unconditional logistic regression model, the risk of total gallstones was positively associated with a taste for salty food (relative risk (RR)=2.31, 95% confidence interval (CI): 1.10–4.84), an intake of lettuce and cabbage (RR = 2.98, 95% CI: 1.47–6.06) and a family history of biliary diseases (RR=5.63, 95% CI: 1.76–17.95), and inversely associated with an intake of salted and dried fish (RR=0.16, 95% CI: 0.04–0.64). When analyzed by type of stones, cholesterol stones were associated with a taste for oily food (RR = 3.87, 95% CI: 1.36–11.03) and pigment stones were positively associated with professional or administrative occupation (RR = 4.74, 95% CI: 1.35–16.68) and inversely associated with a taste for less greasy food (RR = 0.28, 95% CI: 0.10–0.83). Some of these results are consistent with the results of our previous study on biliary tract cancer.
Anti‐metastatic and Anti‐invasive Effects of Polymeric Arg‐Gly‐Asp (RGD) Peptide, Poly(RGD), and Its Analogues
Authors: Saiki Ikuo , Murata Jun , Matsuno Kazuhiko , Ogawa Ryu , Nishi Norio , Tokura Seiichi , Azuma Ichiro
Published: August 2005

We have investigated the anti‐metastatic and anti‐invasive activities of polypeptide analogues based on the Arg‐Gly‐Asp (RGD) adhesive signal in fibronectin, poly(RGD), poly(RGDS)[Arg‐Gly‐Asp‐Ser] and poly(RGDT)[Arg‐Gly‐Asp‐Thr]. These polypeptides containing repetitive RGD sequences were able to inhibit experimental and spontaneous lung metastases of B16‐BL6 cells more effectively than the corresponding monomer peptides. In the spontaneous metastasis model, multiple i.v. administrations of these polymeric peptides before or after surgical excision of the primary tumor resulted in a significant reduction of lung tumor colonies. However, there was no significant difference in ability to inhibit spontaneous lung metastasis among poly(RGD), poly(RGDS) and poly(RGDT), although the carboxy‐terminal amino acid residue (i.e., Xaa in ‐RGDXaa‐) has been shown to play an important role in the expression of cell adhesive character. The treatment with poly(RGD) substantially prolonged the survival time for mice injected s.c. with B16‐BL6 melanoma as compared with the untreated control. We also found that the polypeptides were potently able to inhibit the invasion and migration of tumor cells in vitro. Since these polypeptide analogues showed no antigenicity in the host and had no toxic effect on tumor cells in vitro, they may be potentially useful in the prevention of cancer metastasis.
Transformation of Animal Cells with Human T‐Cell Leukemia Virus Type II
Authors: Miyamoto Kanji , Tomita Noriko , Hayashi Kazuhiko , Akagi Tadaatsu
Published: August 2005

Human T‐cell leukemia virus type II (HTLV‐II) was tested for its ability to transform normal animal cells. The HTLV‐II‐infected human T‐cell line, HTLV‐IIA was lethally X‐irradiated and cocultivated with normal leukocytes of rabbit and crab‐eating monkey and spleen cells of hamster. The transformed cell lines, designated Ra‐IIA, Si‐IIA and Ham‐IIA, were established. These cell lines were shown to be infected with HTLV‐II by the polymerase chain reaction method combined with the digoxigenin‐enzyme‐linked immunosorbent assay method. These cell lines were examined for viral antigens by the indirect immunofluorescence method. Although the cytoplasma of over 90% of the cells of Si‐IIA cell line was brilliantly stained, Ra‐IIA and Ham‐IIA cells were not stained. Electron microscopy of cells of the Si‐IIA line revealed C‐type virus particles in the extracellular spaces.
Specific Detection of Metastasized Human Tumor Cells in Embryonic Chicks by the Polymerase Chain Reaction
Authors: Endo Yoshio , Sasaki Takuma , Harada Fumio , Noguchi Mika
Published: August 2005

We have established a highly sensitive method for specific detection of metastasized human tumor cells in embryonic chicks using the polymerase chain reaction (PCR). The cells (HT‐1080 or KMST‐6) were inoculated into the chorioallantoic membrane vein of the chick embryo and DNA of each embryonic organ was extracted. Then, a human β‐globin‐related sequence (576 bp) in the DNA from the embryonic liver and lung was specifically amplified and detected by gel electrophoresis and by a specific oligonucleotide probe. The amplified fragments from the liver DNA samples increased gradually from 2 h to 7 days after HT‐1080 inoculation. On the other hand, with inoculation of non‐tumorigenic human embryonal fibroblast KMST‐6 cells, the DNA from the embryonic liver 7 days after inoculation did not show the PCR‐amplified product. This detection technique can contribute significantly to the precise detection of microscopic metastasis.
Specialized Localization of P‐Glycoprotein Recognized by MRK 16 Monoclonal Antibody in Endothelial Cells of the Brain and the Spinal Cord
Authors: Sugawara Isamu , Hamada Hirofumi , Tsuruo Takashi , Mori Shigeo
Published: August 2005

This communication describes the cellular and ultrastructural localization in the central nervous system of P‐glycoprotein (P‐GP) recognized by a murine monoclonal antibody, MRK 16. At the ultrastructural level P‐GP was strictly confined to the luminal surface of the endothelial cells which comprise the capillary vessels of the brain and the spinal cord. No P‐GP was found in the endothelial cells of other organs. Our findings may be useful as a means to define the blood‐brain barrier, and they imply that the blood‐brain barrier is anatomically characterized by the presence of intercellular tight junctions between continuous nonfenestrated endothelial cells.
A Deletion Mutation within the Ligand Binding Domain Is Responsible for Activation of Epidermal Growth Factor Receptor Gene in Human Brain Tumors
Authors: Yamazaki Hitoshi , Ohba Yoshito , Tamaoki Norikazu , Shibuya Masabumi
Published: August 2005

Two transplantable cell lines of human glioblastoma multiforme GL‐3 and GL‐5 carried an amplification and overexpression of structurally altered epidermal growth factor (EGF) receptor gene: the 140 kilodalton EGF receptors in these cases exhibited a constitutively expressed tyrosine kinase activity without the ligand. Here, we isolated the abnormal EGF receptor cDNA from GL‐5 cell line, and demonstrated that this cDNA bears a single large intramolecular deletion mutation 801 base pairs long within the ligand binding domain of EGF receptor. In other regions no amino acid substitution was observed. At the level of genomic DNA, this deletion appeared to start from the 1st intron and terminate in the 6th intron of the EGF receptor gene. However, in the two lines of glioblastoma, GL‐3 and GL‐5, the positions of the start or the end of the deletion mutation in these introns were not identical, suggesting an involvement of a unique recombination mechanism in the formation of deletion mutation. A weak but ligand‐independent transforming activity was observed in the deletion‐carrying EGF receptor cDNA.
Mechanism of Cell Damage by Ultrasound in Combination with Hematoporphyrin
Authors: Umemura Shin‐ichiro , Yumita Nagahiko , Nishigaki Ryuichiro , Umemura Koshiro
Published: August 2005

The mechanism of cell damage by ultrasound in combination with hematoporphyrin was studied. Mouse sarcoma 180 cell suspensions were exposed to ultrasound for up to 60 s in the presence and absence of hematoporphyrin, with and without active oxygen scavengers. The cell damage enhancement by hematoporphyrin was suppressed by adding histidine but not by mannitol. The enhancement was doubled in rate by substitution of deuterium oxide medium for normal water. Sonoluminescence was produced in a saline solution under similar acoustic conditions and observed to have spectral components that can excite hematoporphyrin molecules. These results suggest that cell damage enhancement is probably mediated via singlet oxygen generated by ultrasonically activated hematoporphyrin.
Carcinogenicity of Captafol in F344/DuCrj Rats
Authors: Tamano Seiko , Kurata Yasushi , Kawabe Mayumi , Yamamoto Atsushi , Hagiwara Akihiro , Cabral Ricardo , Ito Nobuyuki
Published: August 2005

Captafol was administered at dietary levels of 0 (control), 750 and 1,500 parts per million (ppm) to groups of 50 male and 50 female F344/DuCrj rats for 104 weeks, and then all animals were maintained without captafol for a further 8 weeks, and killed in week 113. Renal cell carcinoma was found in eight of 50 male rats treated with 1,500 ppm and in one of 50 male rats treated with 750 ppm of captafol. The incidences of renal adenomas, including micro‐adenomas, and basophilic altered cell tubules were significantly higher in both sexes treated with captafol than in controls, and the increases were apparently dose‐dependent except that of adenomas in females. The incidences of neoplastic and preneoplastic lesions of the kidney in captafol‐treated animals were higher in males than in females. Captafol also induced hepatocellular carcinomas in four of 50 female rats in the 1,500 ppm group. The incidences of hyperplastic (neoplastic) nodules and foci of cellular alterations in the liver were also significantly increased in both sexes treated with captafol, the increases being dose‐dependent. In conclusion, captafol induced renal cell carcinomas in male rats and hepatocellular carcinomas in female rats.
Inhibition of Avian Myeloblastosis Virus Reverse Transcriptase by Aurochloric Acid
Authors: Semba Mari , Tanaka Noriho , Yamada Masa‐atsu , Takeuchi Fujio , Matsuta Kunio , Miyamoto Terumasa , Hanaoka Fumio , Ui Michio
Published: August 2005

We investigated the inhibitory effects of aurochloric acid (AuCl4H) on reverse transcriptase (RT) derived from avian myeloblastosis virus and DNA polymerase a (pol. a) purified from HeLa S3 cells. The activities of RT, pol. a and E. coli DNA polymerase I (pol. I) with dTTP as the substrate were inhibited 50% at AuCl4H concentrations of 18 μM, 43 μM and 230 μM, respectively. AuCl4H inhibited RT activity competitively with respect to the substrate, dTTP, and uncompetitively with the template/primer, (rA)n(dT)12‐18. In assays with dGTP as the substrate, 50% inhibitions of RT, pol. a and pol. I activities were observed at AuCl4H concentrations of 100 μM, 450 μM and 580 μM, respectively. AuCl4H inhibited RT activity uncompetitively with respect to the substrate, dGTP, and noncompetitively with the template/primer, (rC)n(dG)12‐18. AuCl4H at concentrations causing more than 50% inhibition of RT activity had little inhibitory effect on the colony‐forming ability of HeLa cells or their syntheses of DNA, RNA and protein.
In vitro Progression‐associated c‐H‐ras Activation in Neoplastic Hepatocyte Lines Established from SV40‐T Antigen Gene‐harboring Transgenic Mice
Authors: Li Hong , Liu Jia , Nomura Kimie , Lee Gang‐Hong , Hino Okio , Ohtake Keiko , Aizawa Shinichi , Kitagawa Tomoyuki
Published: August 2005

In order to investigate the molecular mechanisms of multistep hepatocarcinogenesis in SV40‐T antigen gene‐harboring transgenic mice, 9 hepatocellular carcinoma (HCC) lines and 10 “preneoplastic” hepatocyte lines were established from the animals and their biological and molecular changes during culture were investigated. Three of the 9 HCC lines showed progression during culture in terms of growth rate and growth capability in soft agar and in nude mice. This progression was associated with the appearance of activated c‐H‐ras oncogene. Including these 3 lines, H‐ras activation was observed in a total of 7 of the 9 HCC lines (78%), whereas it was found only in 1 of 10 (10%) “preneoplastic” hepatocyte lines. These data thus indicate that H‐ras activation may be an event occurring at a relatively late stage of hepatocarcinogenesis in this transgenic mouse system and that it may serve towards completion of the carcinogenic process together with the T‐antigen.
The Effect of Mass Screening for Breast Cancer: Results of a Multivariate Analysis
Authors: Kuroishi Tetsuo , Tominaga Suketami , Ota Jun , Horino Toshio , Taguchi Tetsuo , Ishida Tsunehiro , Yokoe Takao , Izuo Masaru , Ogita Masami , Itoh Sueyoshi , Abe Rikiya , Yoshida Koichi , Morimoto Tadaoki , Enomoto Kohji , Tashiro Hideya , Kashiki Yoshitomo , Yamamoto Satoru , Kido Choichiro , Honda Kazuyoshi , Sasakawa Michizou , Fukuda Mamoru , Hiromu Hiromu
Published: August 2005

To evaluate the life‐prolonging effect of mass screening for breast cancer, we compared the risk of death for the patients detected by mass screening with that for the patients diagnosed in out‐patient clinics, after adjusting for other relevant factors simultaneously by using the Cox regression model. A multivariate analysis using the Cox regression model in which clinical staging of disease was taken as one of the independent variables, showed that the risk of death for patients detected by mass screening was smaller by 0.765 times than that for patients found in out‐patient clinics although the reduction was not statistically significant. This small reduction might be partly due to the effect of mass screening through early detection even within the same stage, and partly due to length bias, lead time bias and self‐selection bias. When clinical staging of disease was removed from the independent variables, the risk of death for patients detected by mass screening was reduced from 0.765 times to 0.677 times that for patients diagnosed in out‐patient clinics, which was statistically significant (P< 0.01). For asymptomatic patients detected by mass screening, such a reduction of the risk of death was from 0.789 times to 0.555 times that for patients found in out‐patient clinics (P < 0.05). These results suggest that mass screening for breast cancer may contribute to the reduction of the risk of death, although the effect of biases inherent in periodic screening was not removed completely in the present analysis.