bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Cyclin D1 Expression and Induction of Apoptosis by Inostamycin in Small Cell Lung Carcinoma Cells
Authors: Imoto Masaya , Tanabe Keiko , Simizu Siro , Tashiro Etsu , Takada Minoru , Umezawa Kazuo
Published: August 2005

Previously, we demonstrated that inostamycin, an inhibitor of phosphatidylinositol turnover, caused cell cycle arrest at the G1 phase, inhibiting the expression of cyclins D1 and E in normal cells. In the present study, we examined the effects of inostamycin on cell cycle progression and apoptosis in human small cell lung carcinoma Ms‐1 cells. Treatment of exponentially proliferating Ms‐1 cells with low concentrations of inostamycin caused cells to accumulate in the G1 phase. We found that inostamycin decreased cyclin D1, and increased cyclin‐dependent kinase inhibitors such as p21WAF1 and p27KIP1 in Ms‐1 cells. On the other hand, higher concentrations of inostamycin induced morphological apoptosis and DNA fragmentation in Ms‐1 cells without affecting the expression of p53, Bcl‐2 and Bax. Inostamycin‐induced apoptosis was suppressed by an inhibitor of caspase‐3, and a 17 kDa fragment of activated caspase‐3 was detected following inostamycin treatment. Therefore, caspase‐3(‐like) would appear to be involved in inostamycin‐induced apoptosis. On the other hand, an inhibitor of caspase‐3(‐like) proteases did not affect the inhibitory effect of inostamycin on cyclin D1 expression, suggesting that caspase‐3(‐like) proteases were not responsible for inostamycin‐induced G1 arrest.
The Relationship between Population Density and Cancer Mortality in Taiwan
Authors: Yang Chun‐Yuh , Hsieh Ya‐Lun
Published: August 2005

Many investigators have examined urbanization gradients in cancer rates. The purpose of this report was to identify urban‐rural trends in cancer mortality rates (1982–1991) for municipalities in Taiwan. For this purpose, Taiwan's municipalities were classified as rural, suburban, urban, or metropolitan, using population density as an ordinal indicator of the degree of urbanization. Average annual age‐adjusted, site‐specific cancer mortality rates were calculated for both sexes within each population density group. Significant increasing trends with more urbanization were observed in mortality rates for cancers of the lung, pancreas, and kidney among both males and females, as well as male prostate cancer, and female breast and ovary cancer. In addition, this study revealed a significant rural excess for nonmelanoma skin cancer among both males and females, as well as male non‐Hodgkin's lymphoma, and cancers of the female bone, and female connective tissue. Analytic studies for sites with consistent urban‐rural trends may be fruitful in identifying the aspect of population density, or other unmeasured factors, that contribute to these trends.
Expression and Localization of Ornithine Decarboxylase in Reversible Papillomatosis Induced by Uracil in Rat Bladder
Authors: Takada Nobuyasu , Yano Yoshihisa , Otori Kazuhiko , Otani Shuzo , Nomura Shintaro , Kitamura Yukihiko , Fukushima Shoji
Published: August 2005

Direct mechanical irritation by uracil calculi formed following feeding of 3% uracil in the diet to male rats produces severe papillary hyperplasia (papillomatosis, which is reversible) of bladder epithelium. To evaluate the mechanism of the appearance of uracil‐induced papillomatosis, we examined the changes of the enzyme activity and the localization of ornithine decarboxylase (ODC), as well as polyamine biosynthesis, and epithelial proliferation, that accompany the sequential bladder epithelial changes following administration and withdrawal of uracil. Moreover, expression of ODC mRNA was investigated using northern blotting and localization of ODC mRNA was demonstrated using in situ hybridization. ODC activity during uracil administration was maintained at a high level compared to that in normal epithelium, but sharply decreased after cessation of uracil treatment. The accumulation of ODC protein was observed in the proliferating bladder epithelium by immunohistochemical examination and western blotting analysis, and even after cessation of treatment, the protein binding to anti‐ODC antibody remained mildly elevated. Sequential changes of proliferating cell nuclear antigen (PCNA)‐positive cells in the epithelium during the development and disappearance of papillomatosis correlated with ODC activity. ODC mRNA was expressed strongly in the proliferating epithelium in rats treated with uracil and weakly in normal epithelium, in accordance with the location of ODC protein. Consequently, our data demonstrate that cell proliferation in the development of papillomatosis is closely associated with polyamine metabolism, and moreover suggest that ODC activity is up‐regulated at a post‐translational step.
Enhancement of Anti‐tumor Activity of Natural Killer Cells by BALL‐1, a B Cell Lymphoma Line
Authors: Hirashima Mitsuomi , Yoshida Naoko , Seki Masako , Okada Hiroki , Takamura Seishi , Mihara Yosuke
Published: August 2005

The anti‐tumor activity of human peripheral blood mononuclear cells (PBMC) against various tumor cell line cells (K562, Daudi, KMG‐2, and KATOIII) was enhanced by coculture with irradiated BALL‐1, but not with other irradiated B cell line cells (NALM‐1, Namalwa, and Daudi). PBMC cocultured with BALL‐1, however, failed to exhibit evident cytotoxicity against autologous concanavalin A‐induced lymphoblasts. The enhancement of the anti‐tumor activity seemed not to be correlated with EBNA and HLA‐DR expression on B cell line cells. Monoclonal antibodies (mAbs) against interleukin (IL)‐2, interferon‐γ, IL‐12, IL‐15, tumor necrosis factor‐α and lymphotoxin showed little or no suppression of the anti‐tumor activity of PBMC treated with irradiated BALL‐1. Furthermore, the culture supernatants of BALL‐1 failed to enhance the anti‐tumor activity of PBMC, suggesting no involvement of soluble factors in the induction of the anti‐tumor activity. The anti‐tumor activity of PBMC treated with BALL‐1 was synergistically enhanced by an additional IL‐2 stimulation. Periodate‐lysine‐paraformaldehyde‐fixed, but not ethanol‐ or acetone‐fixed, BALL‐1 could significantly enhance the anti‐tumor activity. Furthermore, BALL‐1‐derived membrane fraction, but not that of Daudi, enhances the anti‐tumor activity. It was thus suggested that some membrane glycoproteins on the cell surface of BALL‐1 play a crucial role in the induction of the anti‐tumor activity. By analysis using mAbs against human leukocytes, we found that depletion of CD11b, CD16, and CD56‐positive cells resulted in decreased anti‐tumor activity, suggesting that the main effector cells in the BALL‐1‐induced anti‐tumor activity were natural killer (NK) cells. The present results thus raise the possibility that BALL‐1, probably via membrane glycoproteins, modulates NK cell‐mediated anti‐tumor activity.
Epitope Blocking: Positive and Negative Effects on the Biodistribution of 125I‐Labeled Anti‐Tac Disulfide‐stabilized Fv Fragment of Two Antibodies against Different Epitopes of the Circulating Antigen
Authors: Kobayashi Hisataka , Sun Bao‐Fu , Han Eui‐Sik , Kim Meyoung‐Kon , Le Nhat , Wang Qing‐Cheng , Nelson David L. , Pastan Ira , Waldmann Thomas A. , Paik Chang H. , Carrasquillo Jorge A.
Published: August 2005

Prior in vivo studies using the 125I‐labeled anti‐Tac disulfide‐stabilized variable region fragment (125I‐anti‐Tac dsFv) of monoclonal antibody in the presence of the circulating soluble alpha subunit of the interleukin‐2 receptor (sIL‐2Rα) have shown formation of complexes which interfere with biodistribution. In this study we evaluated the effects of preinjecting HuTac and 7G7/B6, two immunoglobulin Gs (IgGs) that recognize different epitopes of sIL‐2Rα, on the biodistribution of 125I‐anti‐Tac dsFv in mice bearing SP2/Tac tumor xenografts, which produce sIL‐2Rα, or on nude mice injected with 500 ng of sIL‐2Rα. We also evaluated the biodistribution in mice of 125I‐labeled sIL‐2Rα injected alone or with HuTac and 7G7/B6. Injection of either HuTac or 7G7/B6 resulted in complexes with the sIL‐2Rα in serum. Injection of HuTac before 125I‐anti‐Tac dsFv, in SP2/Tac tumor‐bearing mice, resulted in faster clearance of the dsFv from the blood (7.6%ID/g at 30 min), compared to 23.2%ID/g for the no‐antibody control; preinjection of 7G7/B6 prolonged the retention of 125I‐anti‐Tac dsFv to 35.3%ID/g, with more complexes in serum. In mice pre‐injected with 7G7/B6 the concentration of 125I‐anti‐Tac dsFv in tumor was lower (5.2±0.3%ID/g) than in mice preinjected with HuTac (7.9±1.2%ID/g) or in the control group (5.6±0.7%ID/g). In conclusion, while both IgGs formed complexes with sIL‐2Rα and prolonged its retention, preinjection of 7G7/ B6 was detrimental, because the increased circulating sIL‐2Rα still had the epitope recognized by the dsFv available for binding and neutralized the anti‐Tac dsFv upon injection, whereas preinjection of HuTac blocked the epitope.
Antitumor Effect Sonodynamically Induced by Focused Ultrasound in Combination with Ga‐Porphyrin Complex
Authors: Sasaki Kazuaki , Yumita Nagahiko , Nishigaki Ryuichiro , Umemura Shin‐ichiro
Published: August 2005

The antitumor effect of focused ultrasound in combination with Ga‐porphyrin complex, 7,12‐bis(1‐decyloxyethyl)‐Ga(III)‐3,8,13,17 tetramethylporphyrin‐2,18‐dipropionyl diaspartic acid (ATX‐70), on the growth of experimental murine tumors was examined. Walker 256 tumors implanted in rat kidneys were exposed in a progressive wave field for 5 min to focused ultrasound at 500 kHz with the second harmonic (at 1 MHz) superimposed after administration of ATX‐70 to the rats. A significant antitumor effect was obtained at a focal‐spot average acoustic intensity of 12 W/cm2or higher with an ATX‐70 dose of not less than 2.5 mg/kg. When the acoustic intensity was 8 W/cm2or lower, no significant effect was observed even at an ATX‐70 dose of 2.5 mg/kg. Also when the ATX‐70 dose was 1.0 mg/kg or lower, no significant effect was observed even at a focal‐spot average acoustic intensity of 40 W/cm2.
Different Responses Other than the Formation of DNA‐adducts between the Livers of Carcinogen‐resistant Rats (DRH) and Carcinogen‐sensitive Rats (Donryu) to 3′‐Methyl‐4‐dimethylaminoazobenzene Administration
Authors: Yan Ying , Higashi Ken , Yamamura Kaori , Fukamachi Yukiyo , Abe Tetsuya , Gotoh Sadao , Sugiura Tsutomu , Hirano Takeshi , Higashi Taneaki , Ichiba Masayoshi
Published: August 2005

Carcinogen‐resistant inbred DRH rats developed from the Donryu strain showed a remarkably low incidence of liver tumors when they were fed diets containing hepatocarcinogens such as 3′‐methyl‐4‐dimethylaminoazobenzene (3′‐Me‐DAB). In this work, we examined various characteristics of male DRH and Donryu rats during 3′‐Me‐DAB administration for 8 weeks. 32P‐Postlabeling analysis showed that essentially similar levels of DNA‐adducts were generated by the metabolites of 3′‐Me‐DAB in the livers of these two strains of rats at several time points. However, both GADD45 (growth arrest and DNA damage‐inducible) and O6‐methylguanine methyltransferase (putatively DNA damage‐inducible) mRNA levels were increased significantly in Donryu rat livers, but were increased to a lesser extent in DRH rats. [3H]Thymidine incorporation into hepatic DNA began to increase around 10 to 20 days after the start of 3′‐Me‐DAB administration in Donryu rats probably due to DNA repair, while no significant change occurred in DRH rats under the same conditions. Furthermore, inductions of heme oxygenase (due to degradation of heme‐proteins) and hepatocyte growth factor (HGF; cell death and regeneration of hepatocytes) mRNAs were greater in Donryu rat livers than those of DRH, suggesting that the former were more sensitive to cytotoxic effects of 3′‐Me‐DAB than the latter. Another remarkable difference observed between these two strains was the significant induction of cytochrome P‐450 2E1 mRNA in Donryu rat livers; this may contribute to the generation of reactive oxygen intermediates. Finally, increases of glutathione S‐transferase (P‐form) and γ‐glutamyltranspeptidase mRNAs as marker enzymes of preneoplastic changes of hepatocytes were clearly seen only in Donryu rat livers at 6 to 8 weeks after the start of 3′‐Me‐DAB administration. These results indicate that the different susceptibility to hepatocarcinogenesis between these two strains of rats may arise from events other than the DNA adduct formation.
Expression of Cadherin‐Catenin Cell Adhesion Molecules, Phosphorylated Tyrosine Residues and Growth Factor Receptor‐tyrosine Kinases in Gastric Cancers
Authors: Akimoto Shingo , Ochiai Atsushi , Inomata Masafumi , Hirohashi Setsuo
Published: August 2005

Tyrosine phosphorylation of β‐catenin, an intracytoplasmic E‐cadherin‐binding protein, has been shown to disrupt the cadherin‐mediated cell adhesion system in vitro. In order to investigate the relationships of expression and tyrosine phosphorylation of cadherin‐catenin molecules and expression of growth factor receptor‐tyrosine kinase with loose cell‐to‐cell adhesion, immunohistochemical staining for E‐cadherin, α‐ and β‐catenin, phosphorylated tyrosine residues and tyrosine kinase receptors, including c‐erbB‐2, epidermal growth factor‐receptor (EGF‐R), c‐met and K‐sam, in 17 undifferentiated‐ and 10 differentiated‐type human gastric cancers was performed. Loss or reduced expressions of E‐cadherin and α‐ and β‐catenin (11, 11, 10 cancers, respectively) were observed in the former, but not the latter. Diffuse cytoplasmic staining of E‐cadherin, α‐ and β‐catenin and phosphotyrosine residues was observed frequently in the undifferentiated‐type cancers. The cytoplasmic localization of phosphotyrosine residues in undifferentiated‐type cancers was correlated significantly with K‐sam expression (P<0.01) and diffuse cytoplasmic staining of E‐cadherin (P<0.05) and β‐catenin (P<0.05). Expression of K‐sam protein was detected significantly more frequently in undifferentiated‐ (6/17; P<0.05) than differentiated‐type adenocarcinomas whereas the converse applied to c‐erbB‐2 expression (8/10 of the latter, P<0.05). Tyrosine phosphorylation of β‐catenin was directly confirmed in the protein extracts of one undifferentiated‐type gastric cancer. These data indicate that alteration of tyrosine phosphorylation status associated with K‐sam expression may cause the cytoplasmic distribution of cadherin‐catenin molecules and loose cell‐cell adhesion in undifferentiated‐type gastric cancers.
Nonsense Mutation at Codon 63 of the BRCA1 Gene in Japanese Breast Cancer Patients
Authors: Kijima George , Murakami Yoshinori , Ohuchi Noriaki , Satomi Susumu , Sekiya Takao
Published: August 2005

The involvement of abnormalities of the BRCA1 gene in breast cancers in Japanese patients without any family history of this cancer was investigated by polymerase chain reaction‐based single‐strand conformation polymorphism analysis of the DNA sequences corresponding to the zinc finger domain (exons 2, 3 and 5) and the binding domain with Rad51 (exon 11) of the BRCA1 protein. An identical nonsense mutation at codon 63 (TTA to TAA) was found in 2 of 56 (3.5%) breast cancers from independent patients. The nucleotide change was also detected in the DNAs from non‐cancerous tissues of both patients and therefore was a germline mutation. One of the patients was a member of a pedigree involving 3 ovarian cancer and 1 gastric cancer patients, while the other patient had no family history of malignancy. The same germline mutation at codon 63 was reported in four other independent Japanese pedigrees with frequent breast cancer, but not in such families in other countries. These observations suggest that the mutation commonly originated from a single Japanese ancestor. No other mutation of the BRCA1 gene was observed in the samples analyzed in this study. A low incidence of germline mutation and the absence of somatic mutation suggest that the aberration of the BRCA1 gene is involved only in a subset of Japanese breast cancers.
Tumor‐specific Activation of Mitogen‐activated Protein Kinase in Human Colorectal and Gastric Carcinoma Tissues
Authors: Kuno Yasushi , Kondo Ken , Iwata Hiroyuki , Senga Takeshi , Akiyama Seiji , Ito Katsuki , Takagi Hiroshi , Hamaguchi Michinari
Published: August 2005

To search for the signaling events in colorectal carcinoma relevant to its tumorigenesis, we investigated the activity of mitogen‐activated protein kinase (MAPK) in human colorectal carcinoma tissues and paired normal tissues. Of 64 cases examined, approximately 75% (48 cases) showed tumor‐specific activation of MAPK by in situ kinase renaturation assay, as well as in vitro kinase assay with immunoprecipitated MAPK. In addition, tumor‐specific activation of MAPK was associated with the activation of MAPK kinase in the cases we examined. However, no clear correlation of MAPK activation with lymph node involvement, metastatic rate, stage, histological classification, age or sex was observed. These results suggest that the MAPK pathway is involved in colorectal tumor development, but its activation alone is not sufficient for malignant conversion. In contrast to colorectal carcinoma, gastric carcinoma tissues showed a lower rate of MAPK activation, suggesting that the signaling pathway activated in colorectal carcinoma tissues may differ in part from that of gastric carcinoma.
Detection of Epstein‐Barr Virus in Oral Papilloma
Authors: Mizugaki Yuzo , Sugawara Yasuhiko , Shinozaki Fumihiko , Takada Kenzo
Published: August 2005

Fifty‐one cases of malignant and non‐malignant oral diseases were investigated for Epstein‐Barr virus (EBV). EBV DNA was detected by polymerase chain reaction analysis in 2 of 4 papillomas, but not in other tissues including 36 squamous cell carcinomas and 4 leukoplakias. The copy numbers of EBV DNA in the two positive samples were estimated to be 120 and 36 per cell, respectively. Intense EBV DNA signals were detected on papilloma cells by in situ hybridization. DNAs for the benign and malignant types of human papilloma virus were not detected in papilloma tissues. The present results suggest that EBV is a causative agent of oral papilloma.
Sequential T Cell Response Involved in Tumor Rejection of Sarcoma, Meth A, in Syngeneic Mice
Authors: Jiao Yan , Fujimoto Shigeyoshi
Published: August 2005

We investigated the type of T cell response involved in Meth A tumor rejection in primary immune and hyperimmune syngeneic mice. It was found that a CD4+ T cell‐mediated delayed‐type hypersensitivity (DTH) response activating non‐specific killer cells such as macrophages, NK and LAK cells, without a specific CD8+ cytotoxic T lymphocyte (CTL) response, was the major immune response leading to Meth A tumor rejection in primary immune mice. In contrast, the specific CD8+ CTL response was the major response leading to the tumor rejection, in addition to CD4+ T cell‐mediated DTH response, in hyperimmune mice. Analysis of CD4+ T cell clones established from primary immune and hyperimmune spleen cells indicated that a CD4+ T cell clone (C9) of primary immune mice (although only one clone was established) was of Th1 type, and induced cytotoxicity in accessory cells by classic DTH in vitro. Eight CD4+ T cell clones were established from hyperimmune spleen cells. Six out of the eight clones were of the Th2 type and two were Th0‐like. However, no Th1‐type CD4+ T cell clone was established from hyperimmune spleen cells. All of these CD4+ T cell clones, even the Th2‐type clones, were capable of inducing cytotoxicity in vitro in T cell‐depleted accessory cells, as in an in vitro DTH response. We postulate on the basis of these results that the T cell response leading to Meth A tumor rejection in vivo sequentially changed from a CD4+ T cell‐mediated classic DTH response to a CD8+ CTL response, in addition to a cellular response mediated probably by Th2‐type cells, during the process of repeated immunization.
Cytotoxic Mechanisms of FK317, a New Class of Bioreductive Agent with Potent Antitumor Activity
Authors: Naoe Yoshinori , Inami Masamichi , Kawamura Ikuo , Nishigaki Fusako , Tsujimoto Susumu , Matsumoto Sanae , Manda Toshitaka , Shimomura Kyoichi
Published: August 2005

FK317 is a member of a new class of bioreductive agents that exhibit strong cytotoxicity against various human cancer cells. The effect of FK317 was found to be stronger than that of mitomycin C (MMC), adriamycin (ADR) or cisplatin (CDDP). Alkaline elution analysis indicated that FK317 formed interstrand DNA‐DNA and DNA‐protein cross‐links in cells. On the other hand, no DNA single‐strand breaks were observed in the cells treated with FK317. In a cell‐free system the deacetylated metabolites produced cross‐linked DNA under reductive conditions, though FK317 itself did not form DNA‐DNA cross‐links. In order to elucidate the metabolic activation mechanisms, we established an FK317‐resistant subline from human non‐small cell lung cancer cells (Lu99) by stepwise and brief exposure (1 h) to FK317. The resistant subline (Lu99/317) showed cross‐resistance to MMC and carboquone (CQ), but not to ADR or CDDP. DT‐diaphorase, which is one of the activation enzymes of MMC and CQ, was deficient in Lu99/317 cells as determined by enzyme activity assay. However, the levels of NADPH:cytochrome P450 reductase, which is another activation enzyme for MMC and CQ, were comparable in resistant and parent cell lines. Treatment of the cells with dicumarol, an inhibitor of DT‐diaphorase, reduced the cytotoxicity of FK317 to Lu99 cells, but not to Lu99/317 cells. These results indicate that deacetylation of FK317 is necessary for its reductive activation, and deacetylated FK317 is reduced by DT‐diaphorase to form an active metabolite, which produces DNA‐DNA interstrand and DNA‐protein cross‐links that lead to cell death.
Decision Analysis for Treatment of Early Stage Prostate Cancer
Authors: Yoshimura Naoki , Takami Nobuhiko , Ogawa Osamu , Kakehi Yoshiyuki , Okada Yusaku , Fukui Tsuguya , Yoshida Osamu
Published: August 2005

We performed a decision analysis to evaluate the usefulness of pretreatment prediction of clinically significant or insignificant tumor in patients with prostate‐specific antigen (PSA)‐detected stage T1c prostate cancer nonpalpable on rectal examination. Analysis was done for otherwise healthy subjects with 20 years of life expectancy. The prevalence of insignificant tumor among those with T1c prostate cancer was initially assumed to be 0.2. Quality‐adjusted life expectancy was calculated and compared between 2 strategies; one with prediction‐based selection of either radical prostatectomy or watchful waiting and the other with unselective assignment of one of the treatments. The selection strategy was superior when the sensitivity and specificity for detecting clinically significant tumor were 0.92 and 0.73, respectively, as reported by Epstein et al. (1994) using criteria of PSA density and Gleason score in a needle biopsy specimen. Sensitivity analysis revealed that the prediction‐based selection strategy is preferred, with sensitivity and specificity constant, when the prevalence of insignificant tumor exceeds 0.16. On the other hand, when the prevalence of insignificant tumor is kept constant at 0.2, sensitivity should be 0.85 or higher for the prediction strategy to be preferred. As the prevalence of insignificant tumor among those with T1c prostate cancer increased, the prediction‐based selection strategy is preferred with lower values of sensitivity and specificity for detecting significant tumor. These results suggest that a selective treatment strategy of either radical or conservative treatment based on pretreatment prediction for significant tumor is a beneficial alternative to radical prostatectomy unselectively assigned to all patients at the T1c stage, if a reasonable accuracy in prediction is attained.
Lung Cancer Patients Have Increased 8‐Hydroxydeoxyguanosine Levels in Peripheral Lung Tissue DNA
Authors: Inoue Masaaki , Osaki Toshihiro , Noguchi Masayuki , Hirohashi Setsuo , Yasumoto Kosei , Kasai Hiroshi
Published: August 2005

The 8‐hydroxydeoxyguanosine (8‐OH‐dG) levels in the peripheral parts of human lung tissues were compared between lung cancer patients (n=70) and non‐cancer patient controls (n=15). An increased level of 8‐OH‐dG was observed in the lung cancer group, in both the adenocarcinoma and non‐adenocarcinoma (mainly squamous cell carcinoma) groups, as compared to the non‐cancer control group. This result suggests that reactive oxygen species are partly involved in the induction of lung carcinomas (both adenocarcinoma and non‐adenocarcinoma).
Expression of the TCL1 Gene at 14q32 in B‐Cell Malignancies but Not in Adult T‐Cell Leukemia
Authors: Takizawa Jun , Suzuki Ritsuro , Kuroda Hiroyuki , Utsunomiya Atae , Kagami Yoshitoyo , Joh Tatsuroh , Aizawa Yoshifusa , Ueda Ryuzo , Seto Masao
Published: August 2005

The TCL1 gene was recently cloned as a candidate target within the 14q32.1 breakpoint cluster region observed in T‐cell malignancies. We examined the TCL1 gene expression in 21 patients with adult T‐cell leukemia (ATL) and 5 cell lines, because ATL is reported to have frequent chromosome 14 band q32 aberrations. However, 20 of the ATL patients and all 5 cell lines lacked any TCL1 expression on northern blot analysis, and TCL1 transcripts were only very faintly detected in the remaining one patient. Expansion of our analysis to include other types of hematopoietic malignancies revealed strong expression of the TCL1 gene in almost all tumor cells of B‐cell lineage except myelomas. However, no TCL1 signals were encountered in cells of T‐cell or myeloid lineages. In normal human tissues TCL1 was found to be expressed in the spleen, lymph nodes and B‐lymphocytes of peripheral blood. These results indicate that TCL1 is not a major target gene for ATL, but that it may play a role in B‐cell differentiation and proliferation.
Expression of G1→S Transition Regulatory Molecules in Human Urothelial Cancer
Authors: Oya Mototsugu , Schmidt Bettina , Schmitz‐Dräger Bernd J. , Schulz Wolfgang A.
Published: August 2005

Growth of cancer cells is characterized by accelerated passage through the cell cycle, which is often caused by deregulation of the G1→S transition. In this study the expression of G1→S transition regulatory molecules was analyzed in 32 transitional cell carcinoma specimens and fifteen normal tissues obtained by cystectomy or nephroureterectomy of mainly locally advanced tumors, as well as six bladder cancer cell lines. Expression of mRNAs for cyclins D1 and D2 and cyclin‐dependent kinases (CDK) 2 and 4 was investigated by quantitative reverse transcription‐poly‐merase chain reaction. Overexpression of cyclin D1 compared to normal mucosa was observed in 3 tumors (9.4%), but in neither of the cell lines. All tumors with overexpression were moderately differentiated (G2) pT1 or pT2 tumors, and thus among the less advanced specimens. Cyclin D2 was not expressed in normal bladder mucosa or in tumors. The expression of CDK4 mRNA varied within the same range in mucosa, tumors, and cell lines. CDK2 mRNA expression varied more strongly and was diminished in individual tumors and in four cell lines. It is concluded that cyclin D1 overexpression can play an important role in the early stage of urothelial tumorigenesis, driving cell proliferation. Ectopic expression of cyclin D2 or amplification of CDK4 does not occur at a significant frequency in urothelial carcinomas. Different expression patterns of cyclin D1 and CDK2 indicate heterogeneity in the mechanisms of G1→S transition deregulation in individual bladder tumors which may elicit differences in their biological and clinical behavior.
Surgical Significance of Telomerase Activity in Noncancerous Liver Tissue from Patients with Hepatocellular Carcinoma
Authors: Kanamaru Taichi , Morita Yasushi , Itoh Takashi , Yamamoto Masahiro , Kuroda Yoshikazu , Hisatomi Hisashi
Published: August 2005

Telomerase activity has been detected in tissue from noncancerous liver of patients with chronic liver disease, but its functional significance remains to be elucidated. We therefore evaluated the telomerase activity in surgically obtained noncancerous liver tissue from 20 hepatocellular carcinoma (HCC) patients. Two samples of noncancerous liver tissue were obtained from each patient: one from the parenchyma adjacent to the HCC nodules of the resected specimen; the other from the parenchyma distant from the HCC nodules of the remnant liver. Telomerase activity was assayed by a non‐radioisotope quantitative system based on “TRAP‐eze.'’Five samples from the noncancerous liver tissue adjacent to the HCC nodules (25.0%) were telomerase‐positive; all such cases showed high‐grade malignant potential, such as intrahepatic metastasis and/or portal vascular invasion and infiltration of the fibrous capsule in the corresponding HCC nodules, and telomerase positivity showed neither a relationship with the histological activity index scores nor a correlation with liver function. Interestingly, no telomerase activity was detected in any of the 20 samples obtained from the parenchyma of the remnant liver. These results indicate that telomerase in noncancerous liver tissue is associated not with the hepatic condition accompanying HCC, but with the biological characteristics of the tumor itself, and may derive from infiltrating cancer cells. Determination of telomerase status may aid in designing more effective surgical procedures.
Fas and Mutant Estrogen Receptor Chimeric Gene: A Novel Suicide Vector for Tamoxifen‐inducible Apoptosis
Authors: Kodaira Hiroshi , Kume Akihiro , Ogasawara Yoji , Urabe Masashi , Kitano Kiyoshi , Kakizuka Akira , Ozawa Keiya
Published: August 2005

Several cancer gene therapy strategies involve suicide genes to kill the neoplasm, or to regulate effector cells such as lymphocytes. We have developed an inducible apoptosis system with a Fasestrogen receptor fusion protein (MfasER) for rapid elimination of transduced cells. In the present study, we further improved this molecular switch for estrogen‐inducible apoptosis to overcome concerns with the wild‐type estrogen receptor and its natural ligand, 17β‐estradiol (E2). The ligand‐binding domain of MfasER was replaced with that of a mutant estrogen receptor which is unable to bind estrogen yet retains affinity for a synthetic ligand, 4‐hydroxytamoxifen (Tm). The resultant fusion protein (MfasTmR) and MfasER were expressed in L929 cells for examination of their ligand specificities. Tm induced apoptosis in MfasTmR‐expressing cells (L929MfasTmR) at 10‐8M or higher concentrations, but induced no apoptosis in MfasER‐expressing cells (L929MfasER) at up to 10‐6M. On the other hand, E2 induced apoptosis in L929MfasER at concentrations as low as 10‐10–10‐9M, while it did so partially in L929MfasTmR at concentrations greater than 10‐7M. Thus, L929MfasTmR cells were highly susceptible to Tm, but refractory to E2, with 100–1,000 times more tolerance than L929MfasER. These results suggest that the MfasTmR/Tm system would induce apoptosis in the target cells more safely in vivo, working independently of endogenous estrogen.
Applicability of Combination with Tirapazamine in Boron Neutron Capture Therapy
Authors: Masunaga Shin‐ichiro , Ono Koji , Sakurai Yoshinori , Hori Hitoshi , Kobayashi Tooru , Takagaki Masao , Suzuki Minoru , Kinashi Yuko , Akaboshi Mitsuhiko
Published: August 2005

SCC VII tumor‐bearing mice were continuously given 5‐bromo‐2′‐deoxyuridine (BrdU) to label all proliferating cells. After injection of tirapazamine (TPZ), a bioreductive agent, combined with sodium borocaptate‐10B (BSH) or dl‐p‐boronophenylalanine‐10B (BPA) administration, the tumors were irradiated with thermal neutrons, and then isolated and incubated with cytochalasin‐B (a cytokinesis blocker). The micronucleus (MN) frequency in cells without BrdU labeling (quiescent (Q) cells) was determined by means of immunofluorescence staining for BrdU, and that for total cells was obtained from tumors not pretreated with BrdU. Even when no 10B‐compound was administered, TPZ increased the MN frequency of tumor cells including Q cells, resulting in reduction of the difference in MN frequency between total and Q cells, mainly by increasing the MN frequency of Q cells. TPZ increased the MN frequency of Q cells when combined with BPA administration, but TPZ showed no apparent effect on each cell population when combined with BSH. Namely, TPZ reduced the difference in MN frequency between total and Q cells caused by 10B‐compound administration, especially when BPA was administered. From the viewpoint of the overall cell killing effect in boron neutron capture therapy (BNCT), combination with TPZ appeared to be useful in BPA‐BNCT, but not in BSH‐BNCT.
Dose Dependence of 1‐O‐Hexyl‐2,3,5‐trimethylhydroquinone Promotion of Forestomach Carcinogenesis in Rats Pretreated with N‐Ethylnitrosourethane
Authors: Mizoguchi Yasumoto , Hirose Masao , Yamaguchi Tsuyoshi , Boonyaphiphat Plemjit , Miki Tokutaro , Shirai Tomoyuki
Published: August 2005

Post‐initiation dose‐dependent effects of the chemopreventive antioxidant 1‐O‐hexyl‐2,3,5‐trimethylhydroquinone (HTHQ), a potent inhibitor of heterocyclic amine‐induced mutagenesis and carcinogenesis, on the development of forestomach and tongue tumors were investigated in male F344 rats. Groups of 22 rats were treated with 0.01% ethylnitrosourethane (ENUR) as an initiator in the drinking water for 4 weeks, then placed on diet containing 1.0%, 0.5%, 0.25% or 0.125% HTHQ, or basal diet alone for 36 weeks. Further groups of 12 rats each were similarly treated with the different doses of HTHQ or given basal diet alone for 36 weeks without prior ENUR treatment. All animals were killed at week 40. Tongue papillary hyperplasia and papillomas tended to be increased in the groups treated with ENUR followed by 0.5–0.125% HTHQ, though there was no effect at the highest dose, in line with increased bromodeoxyuridine labeling indices. In the forestomach, the incidences of papillomas and carcinomas were also significantly elevated only in the group treated with ENUR followed by 0.125% HTHQ. Without ENUR pretreatment, papillary hyperplasia was found in the 1–0.125% HTHQ groups and the labeling index was also increased, though without clear dose dependence. The results indicate that HTHQ may have very weak or weak promotion potential for tongue and forestomach carcinogenesis, but that both minimum and maximum thresholds for active dose levels may exist.
Enhanced Tumorigenicity of Rat Bladder Squamous Cell Carcinoma Cells after Abrogation of Gap Junctional Intercellular Communication
Authors: Asamoto Makoto , Toriyama‐Baba Hiroyasu , Krutovskikh Vladimir , Cohen Samuel M. , Tsuda Hiroyuki
Published: August 2005

We previously demonstrated a clear tendency for actively communicating rat bladder carcinoma cell lines with elevated expression of connexin 43 mRNA to possess strong tumorigenicity. In the present study, immunohistochemical analysis established that normal bladder epithelium did not express connexin 43 protein, but bladder carcinomas often expressed the protein, particularly on the membranes of cells within areas of squamous cell differentiation. To investigate the role of connexin 43 overexpression in rat bladder carcinoma cells, an anti‐sense connexin 43 expression vector was transfected into BC31 cells having a high communication capacity. In the resultant transfectants, there was little or no communication capacity and connexin 43 expression. The growth rate in vitro was not changed compared to that of cells treated with the vector alone (without the anti‐sense sequence), but tumorigenicity in nude mice was dramatically enhanced. The results indicate that connexin 43 overexpression in rat bladder carcinogenesis is related to squamous cell differentiation, and the protein can have tumor suppressor characteristics, as in other organs.
Inhibition by Sphingosine of Leukemic Cell Killing by Human Monocytes Activated with Interleukin‐2: A Possible Role of Protein Kinase C
Authors: Nakabo Yukiharu , Pabst Michael J.
Published: August 2005

Sphingosine and its analogs, which inhibit protein kinase C (PKC), are known to be potent inducers of apoptosis in tumor cells. However, we were concerned that sphingosine might also interfere with anti‐tumor cells of the immune system. Therefore, we evaluated the effect of sphingosine on activation of human monocytes by interleukin‐2 (IL‐2) for killing of leukemic cells. Monocytes, purified by elutriation and adherence, were activated with IL‐2 or interferon‐gamma (IFN‐γ) in the presence or absence of sphingosine or another inhibitor for 18 h. Then the monocytes were washed and the culture medium was replaced with fresh medium to remove the sphingosine. HL‐60 and K562 leukemic cells were added to the monocyte cultures. Over the next 48 h, the cytotoxic activity of the monocytes towards the leukemic cells was assessed by means of an 111indium‐releasing assay. IL‐2‐activated monocytes lysed 48±3% of HL‐60 cells and 44±3% of K562 cells. Sphingosine, dihydrosphingosine, N, N‐dimethylsphingosine, and the PKC inhibitor H7 inhibited the activation of monocytes by IL‐2, blocking cytotoxic activity against the leukemic cells by approximately 75%. These inhibitors were not toxic to monocytes at the concentrations used. In a PKC assay, sphingosine and H7 inhibited PKC activity in IL‐2‐treated monocytes. Thus, sphingosines, by inhibiting PKC activity, inhibited activation of monocytes by IL‐2, which inhibited the killing of leukemic cells.
Human Tumor Growth Suppression by Apoptosis Induced with Anti‐ErbB‐2 Chimeric Monoclonal Antibody
Authors: Sasaki Shigeru , Tsujisaki Masayuki , Jinnohara Tsuneharu , Ishida Tadao , Sekiya Masuo , Adachi Masaaki , Takahashi Shuji , Hinoda Yuji , Imai Kohzoh
Published: August 2005

We established an anti‐ErbB‐2 mouse‐human chimeric monoclonal antibody (MoAb), CH401, which was able to kill cancer cells overexpressing the ErbB‐2 protein in vitro. The analysis of the killing mechanism indicated that MoAb CH401 might be the first anti‐ErbB‐2 mouse‐human chimeric MoAb which can induce the apoptosis of cancer cells, since morphological changes and DNA fragmentation were recognized in MoAb CH401‐treated cells. The ErbB‐2 receptor appears to have two opposing functions: acting as a receptor both for a growth factor and for an apoptotic factor. Our results indicate that MoAb CH401 treatment may prove to be very useful for cancer therapy.
Promotion by Sodium L‐Ascorbate in Rat Two‐stage Urinary Bladder Carcinogenesis is Dependent on the Interval of Administration
Authors: Chen Tian‐Xin , Wanibuchi Hideki , Murai Takashi , Kitano Mitsuaki , Yamamoto Shinji , Fukushima Shoji
Published: August 2005

In our two‐stage model of rat urinary bladder carcinogenesis employing N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN) as the initiator, sodium L‐ascorbate (Na‐AsA) exhibits dose‐dependent promotion. In the present study, in order to assess the possible reversibility of the promoting effects, we investigated how different administration periods of Na‐AsA influence its promoting activity. In experiment 1, rats were treated with 5% Na‐AsA for different administration periods with or without withdrawal and injected with 5‐bromo‐2′‐deoxyuridine (BrdU) to allow determination of the cell proliferation status. Replicative DNA synthesis in the urinary bladder epithelium was shown to return to normal after removal of the promoting stimulus. In experiment 2, rats were initially given BBN for 4 weeks and subsequently received 16 weeks of Na‐AsA, alternating with basal diet, at intervals of 4, 8 or 16 weeks, within total 32‐week period. The longer the continuous exposure to Na‐AsA, the greater the yield of papillomas and carcinomas in the urinary bladder. In experiment 3, Na‐AsA was given for 4 or 8 weeks after BBN initiation and the animals were killed at weeks 8 and 12. Both promotion of lesion development and increase of DNA synthesis in the urinary bladder epithelium were dependent on the length of exposure to Na‐AsA and the total period of exposure. The results indicate that the promoting effects of Na‐AsA in urinary bladder carcinogenesis are reversible to certain extent after its withdrawal, and the existence of cumulative exposure time threshold seems likely.
Development of Androgen‐independent Carcinomas from Androgen‐dependent Preneoplastic Lesions in the Male Accessory Sex Organs of Rats Treated with 3,2′‐Dimethyl‐4‐aminobiphenyl and Testosterone Propionate
Authors: Iwasaki Shogo , Kato Koji , Mori Toshio , Takahashi Satoru , Futakuchi Mitsuru , Shirai Tomoyuki
Published: August 2005

Two kinds of cancer can be induced in rat male accessory sex organs, one a non‐invasive carcinoma arising in the ventral lobe and the other an invasive lesion which develops in the dorsolateral and anterior lobe as well as the seminal vesicles. In the present study, one group of male rats were given biweekly s.c. injections of 3,2′‐dimethyl‐4‐aminobiphenyl (DMAB) for 20 weeks for induction of non‐invasive carcinomas and the other group received DMAB with 40‐week testosterone propionate for induction of invasive carcinomas. Half of the animals in each group were then subjected to bilateral orchiectomy at week 41 to remove testicular androgen, in order to examine the androgen dependence of both types of carcinomas as well as precancerous lesions. Animals were killed at weeks 41, 46 and 60. All parts of the prostate complex showed involution and significant weight reduction after castration, with a complete disappearance of atypical hyperplasias and carcinomas of the ventral prostate. However, in spite of suppression of development of atypical hyperplasias in the anterior prostate and seminal vesicles, the incidence of invasive carcinomas was not changed. Normal epithelial cells and atypical hyperplasias of all parts of the prostate and seminal vesicles and carcinomas of the ventral prostate were immunohistochemically positive for nuclear androgen receptor, while invasive carcinomas that developed in either castrated or non‐castrated animals were negative. These findings suggest that in the ventral prostate, both precancerous and cancerous lesions are androgen‐dependent, but in the anterior and seminal vesicles, cancerous lesions (invasive carcinomas) are androgen‐independent while precancerous lesions are hormone‐dependent.
Modulating Effects of Diets High in ω‐3 and ω‐6 Fatty Acids in Initiation and Postinitiation Stages of Diethylnitrosamine‐induced Hepatocarcinogenesis in Rats
Authors: Rahman K. M. Wahidur , Sugie Shigeyuki , Okamoto Kiyohisa , Watanabe Tomoyuki , Tanaka Takuji , Mori Hideki
Published: August 2005

The effects of sardine fish oil or corn oil on diethylnitrosamine (DEN)‐induced hepatocarcinogenesis were investigated in male F344 rats. Starting at 5 weeks of age, animals were divided into 11 groups and fed 23.5% corn oil (HCO) (groups 1 and 7) or 5% corn oil (LCO) (groups 2 and 8), 22.5% sardine oil + 1% corn oil (FO) semipurified diet (groups 3 and 9) or basal diet (CE‐2) (groups 4–6, 10 and 11). At 6 weeks of age, all animals except the vehicle‐treated groups were given DEN (200 mg/kg body weight, i.p. once weekly for 3 weeks). One week after the final exposure to DEN, groups 1–3 were changed to the basal diet, and groups 4–6 were switched to the HCO, LCO or FO diet, respectively. Animals in groups 1–3 and 10 were given drinking water containing 0.05% phenobarbital (PB). Liver sections from the animals at the termination of the experiment (24 weeks) were doubly stained for glutathione S‐transferase placental form (GST‐P) and silver‐stained nucleolar organizer regions (AgNORs). The multiplicity of hepatocellular neoplasms of group 1 was significantly larger than that of group 2 or 3. The number of GST‐P‐positive foci of group 2 or 3 was significantly smaller than that of group 1. Among the groups fed the experimental diets in the post initiation phase (groups 4–6), no significant difference was found in the incidence of liver tumors. AgNORs values of the enzyme‐altered foci in rats of the HCO diet groups were larger than those of the other diet groups. These results indicate that the enhancing effect of a high dose of corn oil in hepatocarcinogenesis is mainly present during the initiation phase but not during post initiation phase, and fish oil rich in polyunsaturated ω‐3 fatty acids could inhibit DEN‐induced hepatocarcinogenesis in rats.
Association of MTG8 (ETO/CDR), a Leukemia‐related Protein, with Serine/Threonine Protein Kinases and Heat Shock Protein HSP90 in Human Hematopoietic Cell Lines
Authors: Komori Atsumasa , Sueoka Eisaburo , Fujiki Hirota , Ishii Masaru , Kozu Tomoko
Published: August 2005

A proto‐oncogene, MTG8 (ETO/CDR), is disrupted in the t(8;21) translocation associated with acute myeloid leukemia, and the gene product, MTG8, is a phosphoprotein capable of cell transformation in concert with v‐H‐ras. To obtain insight into functional regulation of MTG8 by phosphorylation, we studied protein kinases that interact with, and phosphorylate, MTG8 in vitro. Recombinant MTG8 protein was first found to be associated with two serine/threonine protein kinases in cell extracts from both HEL cells and a leukemic cell line carrying t(8;21). A cytoplasmic protein kinase of 61 kDa (MTG8N‐kinase) phosphorylated the amino‐terminal of MTG8, and another of 52 kDa (MTG8C‐kinase) phosphorylated the carboxyl‐terminal domain. In addition, we demonstrated that heat shock protein 90 (HSP90) specifically binds to the amino‐terminal domain of MTG8 in vitro and in vivo. Thus, our results shed new light on post‐translational regulation of MTG8, perturbation of which, in AML1‐MTG8 protein, probably contributes to leukemogenesis.
Peroxisome Proliferator‐activated Receptor γ Induces Growth Arrest and Differentiation Markers of Human Colon Cancer Cells
Authors: Kitamura Shinji , Miyazaki Yoshiji , Shinomura Yasuhisa , Kondo Shinya , Kanayama Shuji , Matsuzawa Yuji
Published: August 2005

Peroxisome proliferator‐activated receptor γ (PPARγ), one of the nuclear receptors expressed in adipose tissue, plays an important role in adipocyte differentiation. In this study, we investigated the expression of PPARγ and its role in cellular growth and differentiation in six colon cancer cell lines: HT‐29, CaCo‐2, SW‐480, DLD‐1, LoVo, and T‐84. All six expressed PPARγ mRNA and protein, shown respectively on northern and western blot analyses. Luciferase assay in HT‐29 cells, which strongly express PPARγ showed that troglitazone, a selective ligand for PPAR?, transacti‐vated the transcription of a peroxisome proliferator response element (PPRE)‐driven promoter. Furthermore, troglitazone caused a marked decrease in [3H] thymidine incorporation and G1 cell‐cycle arrest determined by flow cytometry. Finally, troglitazone induced expression of mRNAs for villin and intestinal alkaline phosphatase, markers for enterocyte differentiation. In conclusion, human colon cancer cells express PPARγ, the ligands of which inhibit cell growth and induce differentiation markers.