bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic Properties of Liver Tumors Induced by Dehydroepiandrosterone in F‐344 Rats
Authors: Rao M. Sambasiva , Subbarao V. , Kumar Sujata , Yeldandi Anjana V. , Reddy Janardan K.
Published: August 2005

Dehydroepiandrosterone (DHEA), a C19 adrenal steroid hormone, induces peroxisome proliferation in liver cells and is hepatocarcinogenic in the rat The present study deals with the phenotypic properties of DHEA‐induced liver lesions. A majority of the altered areas (80–87%), neoplastic nodules (>94%) and hepatocellular carcinomas (HCC, 80–100%) lacked the marker enzymes 7‐glutamyltranspeptidase and placental form of glutathione S‐transferase (GSTP). Northern blot analysis of HCC from 4 rats revealed no detectable GSTP mRNA. These HCC, however, showed a marked decrease in the staining of glucose‐6‐phosphatase and adenosine triphosphatase. These results indicate that the phenotypic properties of liver tumors induced by DHEA and amphipathic carboxylate peroxisome proliferators are similar.
Frequent Occurrence of p53 Gene Mutations in Uterine Cancers at Advanced Clinical Stage and with Aggressive Histological Phenotypes
Authors: Tsuda Hitoshi , Hirohashi Setsuo
Published: August 2005

The clinical and pathological significance of mutation of the p53 tumor‐suppressor gene was examined in 108 cases of primary uterine cancers using single‐strand conformation polymorphism and direct DNA sequencing analyses. Mutation of the p53 gene was detected in 19 (31%) of 62 cases of cancer of the uterine corpus and was more frequent in groups at an advanced clinical stage and/or with aggressive histology. Among four adenocarcinomas arising in the lowest portion of the uterine corpus, three showed integration of human papillomavirus (HPV) types 16 and/or 18 DNA, and two of them also showed p53 mutation. In cancer of the uterine cervix, p53 mutations were rare; 1% (3/46) in total, 3% (1/30) of cases with integration of HPV types 16 and/or 18 DNA and 13% (2/16) of cases without HPV DNA integration. Three mutations were detected among two cases at clinical stage IV and two cases of undifferentiated cervical carcinoma. Immunohistochemically, all five cases of uterine cancer which showed diffuse (>50% of cancer cells) nuclear staining of p53 protein also carried the p53 mutation. Therefore, p53 alterations were suggested to be involved in the development of uterine cancers showing aggressive biological behavior. Although a high incidence of HPV DNA integration and a low incidence of pS3 mutation were confirmed in cancer of the uterine cervix, there was no inverse association between integration of HPV types 16 and/or 18 DNA and p53 mutation.
Genomic Organization of the Human WT1 Gene
Authors: Tadokoro Keiko , Oki Noriko , Fujii Hanako , Ohshima Akira , Inoue Tadashi , Yamada Masao
Published: August 2005

We have analyzed the genomic structure of the human WT1 gene, one of the recessive oncogenes for Wilms’tumor at chromosome lip 13. By analyses of three cosmids covering the WT1 gene as well as products generated by polymerase chain reaction, cleavage sites for 10 restriction enzymes were mapped in a region of about 80 kb, and the positions of 10 exons were defined. We also mapped two polymorphic sites for TaqI. Our genomic map will be useful to analyze DNA abnormalities sometimes found in the tumors, as well as loss of heterozygosity.
Differential Changes in Expression of Gap Junction Proteins Connexin 26 and 32 during Hepatocarcinogenesis in Rats
Authors: Sakamoto Hirofumi , Oyamada Masahito , Enomoto Katsuhiko , Mori Michio
Published: August 2005

We examined expressions of the gap junction proteins, connexin 26 (C×26) and 32 (C×32), in preneoplastic and neoplastic lesions during rat hepatocarcinogenesis. A marked reduction in the numher of C×32‐positive gap junctions was observed in 17% of the glutathione S‐transferase placental form‐positive foci, whereas 44% of the foci showed increased expression of C×26. Most hyperplastic nodules exhibited decreased expression of C×32, whereas 16% of the nodules showed increased expression of C×26. In hepatocellular carcinomas, expressions of both C×32 and C×26 were significantly reduced. These results suggest that the expressions of C×32 and 26 are differentially regulated during hepatocarcinogenesis, and that the decrease in C×32 expression occurs earlier, whereas reduction in C×26 expression occurs later in association with promotion and progression of carcinogenesis.
Enhancement by Monocytes of Perform Production and Its Gene Expression by Human CD8+ T Cells Stimulated with Interleukin‐2
Authors: Sugihara Kohji , Sone Saburo , Shono Masayuki , Nii Akihiko , Munekata Masanobu , Okumura Ko , Ogura Takeshi
Published: August 2005

Pore‐forming protein (PFP) is an important effector molecule for cytotoxicity mediated by cytotoxic T cells and NK cells. In the present study, the effect of monocytes on PFP production by inter‐leukin‐2 (IL‐2)‐stimulated T lymphocytes was examined. Highly purified lymphocytes (>99%) and monocytes (> 90%) were isolated by centrifugal elutriation from peripheral blood of healthy donors, and, CD4+ and CD8+ cells were isolated from the purified lymphocytes by using antibody‐bound magnetic beads. PFP production was quantitated with a universal microspectrophotometer in combination with immunostaining using anti‐PFP antibody. Monocytes did not produce any PFP. High levels of PFP production were observed in CD8+ cells, but not CD4+ cells after incubation for 4 days with IL‐2. Addition of monocytes to cultures of CD8 + cells resulted in significant augmentation of PFP production after 3 days’ stimulation with IL‐2. Monokines (TNFα and IL‐6) caused a significant increase in PFP production by IL‐2‐stimulated CD8+ cells. Northern blot analysis revealed that the PFP mRNA level was enhanced by stimulation with IL‐2, and that addition of monocytes to cultures of CD8 + cells plus IL‐2 augmented their PFP mRNA expression. These observations suggest that monocytes are important in in situ regulation of the CD8 + T cell‐mediated cytotoxic response through production of PFP.
VLA‐4 Molecules on Tumor Cells Initiate an Adhesive Interaction with VCAM‐1 Molecules on Endothelial Cell Surface
Authors: Kawaguchi Satoshi , Kikuchi Kokichi , Ishii Seiichi , Takada Yoshikazu , Kobayashi Seiichi , Uede Toshimitsu
Published: August 2005

To elucidate the role of VLA‐4 (α4β1 integrin) in tumor metastasis, we have transfected cDNA coding z4 subunit into human flbrosarcoma (HT1080) cells. VLA‐4‐overexpressing HT‐VC1 cells exhibited increased ability to interact with known ligands for VLA‐4, such as CS1 peptide and VCAM‐1 (vascular cell adhesion molecule‐1). In addition, thein vitroinvasive ability of HT‐VC1 cells was augmented and the mRNA for type IV collagenase was increased in HT‐VC1 cells. The induction of VCAM‐1 molecules on lung endothelial cells of nude mice by tumor necrosis factor‐α treatment resulted in augmentation ofin vivoHT‐VC1 cell adhesion to the lung endothelial cells. Thus, the VLA‐4 molecules on tumor cells initiate an adhesive interaction with VCAM‐1 molecules on endothelial cells, that is important for hematogenous metastasis.
Differences in Chemotaxis to Fibronectin in Weakly and Highly Metastatic Tumor Cells
Authors: Murata Jun , Saiki Ikuo , Yonedal Junya , Azuma Ichiro
Published: August 2005

We have examined the chemotactic ability of tumor cell lines with different metastatic potential to plasma fibronectin in Transwell chamber assay. Human renal carcinoma cells with highly metastatic potential, SN12 C‐2, chemotactically migrated to fibronectin (10 μg/ml) about three‐fold more strongly than weakly metastatic SN12 C‐4 cells. Similarly, murine melanoma B16–BL6 cells (highly metastatic) showed higher motility to soluble fibronectin in comparison with weakly metastatic B16–F1 cells. Anti‐VLA‐α3 and β1, antibodies potently blocked the chemotaxis of both highly and weakly metastatic cells (SN12 C‐2 and C‐4) to fibronectin. This implies that the migration of both C‐2 and C‐4 cells to fibronectin is basically mediated by VLA‐3 receptor. In contrast, the anti‐VLA‐as antibody and RGDS peptide significantly inhibited the chemotaxis of SN12 C‐2 cells to fibronectin, but did not affect weakly metastatic SN12 C‐4 cells. These results suggest that the chemotactic ability to fibronectin positively correlates with the metastatic potential in SN12 and B16 cell lines, and that VLA‐5 receptor is concerned in the motility of highly metastatic SN12 C‐2 cells to soluble fibronectin.
Detection of Locally Recurrent Colorectal Cancer with Radiolabeled Monoclonal Antibody H‐15
Authors: Sakamoto Junichi , Kato Tomoyuki , Watanabe Tadashi , Murayama Hiroki , Wada Kimio , Sato Tsuyoshi , Takagi Hiroshi , Kondo Kunio , Sasaki Fumio , Kido Choichiro , Nakazato Hiroaki , Ueda Ryuzo , Takahashi Toshitada
Published: August 2005

H‐15 (HT‐29‐15) is an IgG1 mouse monoclonal antibody (mAb) to a cell surface antigen (molecular mass, 200,000 daltons) present on virtually all colorectal cancers and also in normal pancreatic ducts and bile ducts, but not in other normal tissues. The biological distribution and imaging characteristics of iodine‐131 (l31I)‐labeled mAb H‐15 were studied in 5 primary colorectal cancer patients and 9 patients with local recurrence of colorectal cancer. H‐15 mAb labeled with 0.5‐10 mCi of 131I was administered 7 to 8 days before surgery at 4 dose levels, ranging from 0.2 to 6 nig. Selective mAb H‐15 localization to tumor tissues was demonstrated in 6 of 12 patients with antigen‐positive tumors: in two patients, recurrent tumors were negative to H‐15 mAb, although the primary tumors were positive. In six patients with positive radioimaging, tumor:normal tissue ratios ranged from 2.05 to 5.35 and tumor:serum ratios from 1,18 to 2.73. The clarity of images seems to correlate well with the latter ratios. Technetium‐99 (99mTc)‐albumin blood pool studies in selected cases showed that local recurrence of colorectal cancers was hypovascular, emphasizing the selective localization of mAb H‐15 despite poor blood flow distribution in the tumors. The results altogether demonstrated that radioimmnnodetection with 131I mAb H‐15 is valuable for differentiating recurrent colorectal cancer from granuloma formation after surgery.
Establishment of a Human Small Cell Lung Carcinoma Cell Line Carrying Amplification of c‐myc Gene and Chromosomal Translocation of t(3p;6p) and t(12q;17p)
Authors: Kato Atsushi , Kamiyama Takashi , Yamaguchi Sachiko , Sudo Katsuko , Mori Shigeo , Sekiguchi Morimasa , Aoki Nobuo , Shibuya Masabumi
Published: August 2005

A transplantable tumor and an in vitro culture cell line (GK‐T3) were established from metastatic liver tissue of human small cell lung carcinoma (SCLC). Southern blot analysis revealed about 30‐fold amplification of c‐myc gene in the tumor cells in liver, xenografts, and in vitro cell line. The degree of c‐myc amplification was essentially conserved through serial passages in nude mice and cultivation in vitro. The level of c‐myc mRNA was significantly increased in these cells. Cytogenetically, numerical and complex structural abnormalities were observed in GK‐T3 cells, including t(3p;6p), t(12q;17p), two homogeneously staining regions (hsrs) and several double minutes (dmins). These results suggest that activation of c‐myc gene and alteration of gene(s) round these chromosomal breakpoints may play a role in tumorigenesis of GK‐T3 SCLC.
Strong Inhibition of 2‐Amino‐6‐methyldipyrido[l,2‐a:3′,2′‐d]imidazole‐induced Mutagenesis and Hepatocarcinogenesis by 1‐O‐Hexyl‐2,3,5‐trimethylhydroquinone
Authors: Hirose Masao , Akagi Keisuke , Hasegawa Ryohei , Satoh Toshio , Nihro Yasunori , Miki Tokutaro , Sugimura Takashi , Ito Nobuyuki
Published: August 2005

The effects of 3‐O‐dodecylcarbomethylascorbic acid (3‐O‐DAsA), 3‐O‐ethylascorbic acid (3‐O‐EAsA) and 1‐O‐hexy1‐2,3,5‐trimethylhydroquinone (HTHQ) on 2‐amino‐6‐methyldipyrido[l,2‐a:3′,2′‐d]‐imidazole (Glu‐P‐1)‐induced mutagenesis and hepatocarcinogenesis were examined. In a Salmonella assay, addition of 2.5 to 20.0 rag of HTHQ to Salmonella TA 98 in the presence of S‐9 mixture dose‐dependently inhibited Glu‐P‐1‐induced mutagenesis. The highest dose showed a 99% reduction in revertants. 3‐O‐DAsA and 3‐O‐EAsA were without effect. In an animal study using the medium‐term bioassay system for the detection of hepatocarcinogens or hepatopromoters in F344 male rats, treatment with Glu‐P‐1 alone was associated with a significant increase in the number and area of GST‐P‐positive foci (47.5±8.9 and 11.1±4.7, respectively). Combined treatment with 1.0% HTHQ significantly reduced the number and area of GST‐P‐positive foci (to 8.1±2.1 and 0.6±0.2) while 3‐O‐DASA exerted marginal inhibition and 3‐O‐EAsA had no effect. On the other hand, all three of these compounds slightly enhanced the numbers and areas of foci when given alone. The results indicate that HTHQ is a potent chemopreventer of Glu‐P‐1‐induced hepatocarcinogenesis.
Atypical Mitosis in Gastric Intestinal Metaplasia in Japanese Patients
Authors: Rubio Carlos A. , Kato Yo , Kitagawa Tomoyuki
Published: August 2005

The characteristics of the mitotic figures occurring in intestinal metaplasia of the gastric mucosa were investigated in 50 consecutive gastrectomy specimens. The specimens contained, in addition, early gastric cancer of intestinal type (n = 38) or of diffuse type (n = 12). One hundred or more consecutive mitoses/specimen were studied by high‐power microscopy (× 1000). Of the 5,140 mitoses, 1,030 (i.e. 20.0%, range 8–34%) were considered as atypical according to a previous classification. The presence of atypical mitosis was not influenced by the gender or age of the patient, or the histological type of the tumor present in the specimen. Studies of gastrectomy specimens from Swedish patients with early gastric cancer showed a much lower frequency of mitotic figures/specimen and occasional atypical mitosis. The high frequency of atypical mitosis in intestinal metaplasia in the gastric mucosa of Japanese nationals may mirror a profound genetic instability in that mucosa, and suggests that intestinal metaplasia with atypical mitosis may be a precancerous lesion in the Japanese.
Inhibitory Effects of Sizofiran on Anticancer Agent‐ or X‐Ray‐induced Sister Chromatid Exchanges and Mitotic Block in Murine Bone Marrow Cells
Authors: Yang Zhi‐bo , Tsuchiya Yoshinori , Arika Tadashi , Hosokawa Masuo
Published: August 2005

The inhibitory effects of a biological response modifier (BRM), sizofiran, on sister chromatid exchanges (SCEs) in the bone marrow cells of mice treated with various anticancer agents or irradiation were investigated. Sizofiran (10 mg/kg i.m.) inhibited SCEs induced by mitomycin C (2 mg/kg i.v.), adriamycin (20 mg/kg i.v.) and cyclophosphamide (20 mg/kg i.v.) by about 20%, respectively. Analysis of the SCEs in vivo after irradiation plus sizofiran indicated that SCE levels were significantly lower than those observed in mice exposed to irradiation without sizofiran. Moreover, the effects of sizofiran were dependent on the timing of administration. Our results indicated that sizofiran should be administered simultaneously or soon after irradiation in order to minimize damage. Sizofiran also markedly restored the bone marrow cell mitosis which had been suppressed by anticancer agents, and this action was closely correlated with the prevention of increase in SCEs. These results indicate that in addition to immunopotentiating activity, sizofiran may play a role in preventing chromosomal damage induced by cancer chemotherapy and radiotherapy.
Identification of K‐ras Oncogene Mutations in the Pure Pancreatic Juice of Patients with Ductal Pancreatic Cancers
Authors: Watanabe Hiroyuki , Sawabu Norio , Ohta Hideki , Satomura Yoshitake , Yamakawa Osamu , Motoo Yoshiharu , Okai Takashi , Takahashi Hirokazu , Wakabayashi Tokio
Published: August 2005

Pancreatic cancer is detected on the basis of morphological changes delineated by means of various image‐diagnostic methods. However, differentiation between chronic pancreatitis and pancreatic cancer, especially at the early stage, is not always simple when based upon the morphological changes alone. Therefore, we attempted to elucidate K‐ras mutations in the sediment of pure pancreatic juice (PPJ) containing exfoliated ductal pancreatic cancer cells. PPJ was collected endoscopically from 20 patients with pancreatic cancer (PC) and 18 patients with chronic pancreatitis (CP). Polymerase chain reaction and allele specific oligonucleotide dot blot hybridization for K‐ras mutations were performed with the DNA extracted from these samples. A K‐ras mutation at codon 12 was identified in the PPJ of 11/20 (55%) of the patients with PC. On the other hand, the same mutation was not identified in the PPJ of any patient with CP. Moreover, K‐ras mutations at codons 13 and 61 were not recognized in the PPJ of any patient with either PC or CP. These findings suggested that the presence of a K‐ras mutation at codon 12 in PPJ would be useful in confirming the diagnosis of PC.
High Sensitivity of LEC Rats with Chronic Hepatitis to Hepatocarcinogenesis: Decreases in Unscheduled and Replicative DNA Synthesis of the Hepatocytes
Authors: Sakamoto Hirofumi , Sawada Norimasa , Kamimura Yasuhiro , Enomoto Katsuhiko , Mori Michio
Published: August 2005

We carried out the following three experiments to clarify the mechanism of hepatocarcinogenesis in Long‐Evans Cinnamon (LEC) rats. (1) Sensitivity to diethylnitrosamine (DEN): LEC rats (8 and 25 weeks old) without and with hepatitis and age‐matched F344 rats were administered an intraperitoneal injection of a low dose of DEN. Eight weeks after the injection, the numbers of glutathione‐S‐transferase placental‐form (GST‐P)‐positive foci in the 33‐week‐old LEC rat liver were significantly higher than those in the livers of the other three groups of rats. (2) Potential for unscheduled DNA synthesis (UDS): Isolated hepatocytes of 25‐week‐old LEC rats with chronic hepatitis showed about one‐third the level of UDS induced by UV irradiation, as compared to that of age‐matched F344 rats, while no significant difference was found between the UDS of isolated hepatocytes of 8‐week‐old LEC rats and age‐matched F344 rats. (3) Potential for proliferation: Isolated hepatocytes from 8‐week‐old LEC rats responded well to epidermal growth factor (EGF) in culture, to almost the same degree as F344 rat hepatocytes, while a remarkable decrease in the responsiveness of hepatocytes isolated from 25‐week‐old LEC rats to EGF was found. These results suggested that LEC rat hepatocellular carcinoma could be naturally initiated after the onset of hepatitis by carcinogens contaminating food and the environment, probably due to the reduction of DNA repair activity, after which initiated hepatocytes selectively proliferate in response to growth stimuli endogenously produced as a result of continuous loss of hepatocytes (chronic hepatitis), because of a decrease in growth activity of non‐initiated hepatocytes.
High Frequency of Thyroid Tumor Induction by N‐Methyl‐N′‐nitro‐N‐nitrosoguanidine in the Hermaphroditic Fish Rivulus marmoratus
Authors: Park Eun‐Ho , Chang Hwa‐Hyoung , Lee Kyoung‐Charn , Kweon Hee‐Seok , Heo Ok‐Soon , Ha Kwang‐Won
Published: August 2005

In the self‐fertilizing hermaphroditic fish, Rivulus marmoratus, the susceptibility to tumor induction by N‐methyl‐N‐nitro‐N‐nitrosoguanidine(MNNG) was evaluated. Seven‐day‐old fish larvaewere exposed for 2 h toMNNG at concentrations ranging from 5 to 25 ppm in a static water bath. The exposed fish were observed at 2 and 4 monthsafter carcinogen treatmentto assess tumor development. Within 4‐ months after25 ppmMNNG exposure, nearly all fish developed thyroid tumors. The tumor incidenceswere dose‐ and time‐dependent, and the latent period of tumor induction was less than 2 months. Most induced neoplasms were papillary carcinomas similar histologically to those of rodents and humans, and the tumors were serially transplantable to other fish of the same species. These results demonstratethat rivulus could be useful as a model of thyroid carcinogenesis.
Deletion of WT1 and WIT1 Genes and Loss of Heterozygosity on Chromosome 11p in Wilms Tumors in Japan
Authors: Kaneko Yasuhiko , Takeda Osamu , Homma Chieko , Maseki Nobuo , Miyoshi Hiroyuki , Tsunematsu Yukiko , Williams Bryan G. , Saunders Grady F. , Sakurai Masaharu
Published: August 2005

Six of 39 sporadic Wilms tumors had gross homozygous or hemizygous WT1 and WIT1 deletions. Two Wilms tumor‐aniridia‐genitourinary abnormalities‐mental retardation syndrome patients had total hemizygous WT1 and WIT1 deletions in both constitutional and nonsporadic type tumor cells. Four of the 8 tumors with WT1 and WIT1 deletions showed loss of constitutional heterozygosity (LOH) for markers limited to the 11p13 region. Seven of 19 Wilms tumors with neither WT1 nor WIT1 deletions also had LOH on 11p; 4 in the 11p15–11p13 region, one in the 11p15 and possibly also 11p13 regions, and two solely in the 11lp15 region. Thus, 15 of the 41 Wilms tumors (37%) had WT1 and WIT1 deletions or LOH on 11p, and only 2 of the 27 tumors whose nonneoplastic normal tissues were available for study showed LOH limited to the 11p15 region. None of the 7 non‐Wilms childhood renal tumors showed WT1 or WIT1 deletions, or LOH on 11p. These data suggest that Japanese Wilms tumors may be characterized by a higher incidence of the gross WT1 deletion and a lower incidence of LOH limited to the 11p15 region than the Caucasian counterparts. These moleculargenetic features may be contributing to the lower incidence of Wilms tumors in Japanese children than in Caucasian ones.
Transforming Growth Factor‐α Expression of Renal Proximal Tubules in Wistar Rats Treated with Ferric and Aluminum Nitrilotriacetate
Authors: Deguchi Jiro , Kawabata Teruyuki , Kondo Asami , Okada Shigeru
Published: August 2005

A high incidence of renal adenocarcinoma has been observed in rats treated with ferric nitrilotriacetate (Fe‐NTA) but not in rats treated with aluminum nitrilotriacetate (Al‐NTA). Transforming growth factor (TGF)‐α is one of the several cytokines that is known to be expressed in human and rat renal adenocarcinomas. However, its role in neoplastic transformation is still questionable. Therefore, we investigated the effect of repeated Fe‐NTA and Al‐NTA administration on renal TGF‐α expression. Male Wistar rats were given Fe‐NTA (n = 16, 5–10 mg FeAg) and Al‐NTA (n = 19, 1–2 mg Al/kg) i.p., three times a week for 3 or 12 weeks. Another group of rats (n=4) was given Fe‐NTA (5–10 mg FeAg) three times a week for 12 weeks and then left untreated for one year. Immunoreactivity for TGF‐α was positive in the collecting ducts and on the apical surface of proximal tubules in the outer stripe of the outer medulla in all the animals including NTA‐injected control animals. However, TGF‐α immunoreactivity in the regenerative proximal tubular epithelium was observed only in the animals treated with Fe‐NTA for 12 weeks. Northern blot analysis also showed expression of TGF‐α mRNA only in animals treated with Fe‐NTA for 12 weeks. The expression of TGF‐α mRNA in the kidney was stronger than that in the liver or brain, TGF‐α was also positive in renal cell carcinoma found in animals treated with Fe‐NTA for 12 weeks and left untreated for one year. These results suggest that TGF‐α expression may play an important role in renal carcinogenesis and that it may be a sensitive marker during the induction stage of renal cell carcinoma.
Potentiation of in vivo Antitumor Effects of Recombinant Interleukin‐1α by Gelatin Conjugation
Authors: Tabata Yasuhiko , Uno Kazuko , Ikada Yoshito , Kishida Tsunataro , Muramatsu Shigeru
Published: August 2005

Chemical conjugation of a recombinant human interleukin‐1α (IL‐1) with gelatin was conducted using a water‐soluble carbodiimide in an attempt to augment the indirect effect of IL‐1 on in vivo tumor cell growth in mice. Chromatographic studies of the IL‐1‐gelatin conjugate demonstrated that the apparent molecular weight of IL‐1 was increased by the gelatin conjugation and about 60% of IL‐1 activity was retained in the prepared conjugate. Intraperitoneal (i.p.) injection of the conjugate significantly suppressed the intraperitoneal growth of a subline of Meth A fibrosarcoma cells (RR1 cells), compared with the effect of free IL‐1 at the same dose, although the cells per se were resistant not only to free IL‐1 but also to gelatin‐conjugated IL‐1. Simple mixing of gelatin with free IL‐1 did not augment the in vivo antitumor effect as compared with that of free IL‐1. Gelatin conjugation improved the in vivo stability of IL‐1. Prolonged retention of IL‐1 activity in the peritoneal cavity as well as the circulation of mice was observed after i.p. injection of the IL‐1‐gelatin conjugate in comparison with free IL‐1 injection, irrespective of the presence of tumor cells. Gelatin conjugation was effective in augmenting the in vivo antitumor effects of IL‐1 to activate host cells, e.g. macrophages (Mø). The i.p. injection of the conjugate enhanced Mø infiltration into the peritoneal cavity of tumor‐bearing mice and peritoneal Mø were strongly activated to inhibit the in vitro growth of RR1 cells. Thus, gelatin conjugation was effective in augmenting the indirect effect of IL‐1 via host cells, leading to a high suppressive effect on in vivo growth of tumor cells.
Chromosomal Mapping of Genetic Locus Associated with Thymus‐size Enlargement in BUF/Mna Rats
Authors: Murakumo Yoshiki , Takahashi Masahide , Arakawa Atsushi , Saito Mitsuhiro , Amo Hiroyuki , Katoh Hideki , Matsuyama Mutsushi
Published: August 2005

The thymoma‐prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr‐1. At pre‐thymoma age, BUF/Mna rats have extremely large thyrauses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten‐1, which contributes to thymus enlargement in a backcross population. Linkage studies between Ten‐1 and microsatellite markers in backcross rats of (WKY/NCrj×BUF/Mna)Fl×BUF/Mna have led to the localization of Ten‐1 in chromosome 1. This result may provide an approach to clone Tsr‐1, which could be allelic to Ten‐1.
c‐Myc Selectively Regulates the Latent Period and Erythroid‐specific Genes in Murine Erythroleukemia Cell Differentiation
Authors: Shoji Wataru , Ohmori Yasufumi , Obinata Masuo
Published: August 2005

During the latent period of murinc erythroleukemia (MEL) cell differentiation, c‐myc levels showed a significant change and the overexpression of the transferred c‐myc gene inhibited the commitment and differentiation of MEL cells, suggesting that c‐Myc may he a key molecule for the commitment. Since c‐Myc may function as a DNA binding transcription factor, we examined whether c‐Myc regulates the latent period genes (hsp and hsc70, MER5, Id and Spi‐1 genes) and the erythroidspecific genes [β‐globin, glycophorin, δ‐aminolevulinic acid synthase (ALAS‐E), GATA‐1 and erythropoietin receptor (EpoR)] in the MEL cell transformant having transferred c‐myc gene. The overexpression of c‐myc gene affected the latent period genes in different ways: hsc and hsp 70 genes and Id gene were positively regulated, while expression of MER5 gene was repressed. While c‐myc is thought to be involved in DNA replication, its overexpression showed no effect on the expression of proliferating cell specific nuclear antigen or DNA polymerase α. The overexpression of c‐myc repressed the expression of glycophorin, ALAS‐E and β‐glohin genes, of the five erythroid‐specific genes, but had no effect on expression of GATA‐1 or EpoR gene. These results suggest that c‐Myc differentially regulates the expression of the latent period and erythroid‐specific genes.
Sequential Observation of Rat Prostate Lesion Development Induced by 3,2′‐Dimethyl‐4‐aminobiphenyl and Testosterone
Authors: Shirai Tomoyuki , Imaida Katsumi , Iwasaki Shogo , Mori Toshio , Tada Mariko , Ito Nobuyuki
Published: August 2005

3,2′‐Dimethyl‐4‐aminobiphenyl (DMAB), when combined with high doses of testosterone propionate (TP) induces invasive adenocarcinomas with metastatic potential in the rat prostate. The processes underlying this tumor development, including the involvement of atypical hyperplasias, were sequentially investigated in F344 rats. DMAB was given subcutaneously at a dose of 50 mg/kg body weight 10 times at 2‐week intervals. TP was administered chronically (in Silastic tubes) from the beginning of the experiment or after the DMAB administration until termination (week 60). Invasive adenocarcinomas were induced in the lateral and anterior prostate as well as the seminal vesicles. Atypical hyperplasias appeared from an early stage, with the later appearance of cancers being closely associated with such foci of morphological alteration. The findings confirm that combined administration of DMAB and pharmacological doses of TP yields invasive adenocarcinomas in the rat prostate and provide further support for the conclusion that atypical hyperplasias are premalignant lesions.
A Cancer‐reactive Human Monoclonal Antibody Derived from a Colonic Cancer Patient Treated with Local Immunotherapy
Authors: Yagyu Toshio , Monden Takushi , Baba Masashi , Tamaki Yasuhiro , Takeda Tsutomu , Kobayashi Tetsuro , Shimano Takashi , Tsuji Yoshiyuki , Matsushita Hirohisa , Osawa Hisao , Murakami Hiroki , Mori Takesada
Published: August 2005

A human monoclonal antibody, YJ‐37 (IgM) was generated through the fusion of human B lymphoblastoid cell line HO‐323 with the regional lymph node lymphocytes from a colonic cancer patient who was treated with a local immunotherapy. This antibody was purified and conjugated with biotin, after which direct immunohistochemical staining was performed. The results revealed that YJ‐37 selectively reacted with colonic cancer (7/19), gastric cancer (3/6), endometrial cancer (1/2) and colonic adenoma (7/13), but not with normal epithelia. Membrane immunofluorescence and FACS analysis also showed that YJ‐37 bound to tumor cell surfaces. Furthermore, the chemical structure of the antigen defined by YJ‐37 was analyzed by means of thin‐layer chromatography immunostaining and ELISA. The results indicated that YJ‐37 reacted with sialylated lacto‐series carbohydrate chains, which have been reported to accumulate in cancer cells.
Establishment and Characterization of BALB/c Retroperitoneal Sarcoma with Spontaneous Liver Metastases
Authors: Fujii Yuzo , Itoyanagi Hitomi , Saegusa Yoshiyuki , Kuro‐o Masaki , Matsuda Yoichi , Shiroko Yasuko , Eriguchi Masazumi , Hasumi Ken‐ichiro
Published: August 2005

The objective of this study was to examine the identity and characteristics of a spontaneously occurring murine retroperitoneal tumor of BALB/c mouse origin that selectively metastasized to the liver. From the primary tumor, a permanent cell line, termed LMFS (liver metastasis from sarcoma) was established in vivo and in vitro. After a subcutaneous injection of more than 1 × 105 cells in the side back of mice, the LMFS cells proliferated at the inoculation site (100% take) and induced metastatic nodules spontaneously in the liver, but not in the lung. By the limiting dilution technique, a cloned cell line, LMFS‐1, was established in vitro. The LMFS‐1 cell line had similar morphological characteristics to the LMFS cells both in vitro and in vivo. The doubling time of the LMFS‐1 cell line was 10 h in passage 60. The number of chromosomes ranged from 71 to 108 and 93% of metaphases showed near‐tetraploidy. In microscopic examination, no specific arrangement of the LMFS tumor cells was seen; the LMFS cell had medium‐ to large‐sized atypical nuclei and clear and large cytoplasm. Electronmicroscopy showed that the cytoplasm of the LMFS cell had a moderate amount of rough‐surfaced endoplasmic reticulum but no desmosomes or microvilli. Immunohistochemically, the LMFS cells were positive for vimentin, but showed no reaction for keratin or cytokeratin. Therefore, the LMFS tumor was considered to be an undifferentiated sarcoma. The LMFS cell line should be a useful tool not only for studies of metastasis, but also for experiments on the therapy of hepatic tumors.
Triflavin, an Arg‐Gly‐Asp‐containing Peptide, Inhibits Tumor Cell‐induced Platelet Aggregation
Authors: Sheu Joen R. , Lin Chao H. , Peng Hui C. , Teng Che M. , Huang Tur F.
Published: August 2005

In this study, we examined the effect of triflavin, an Arg‐Gly‐Asp (RGD)‐containing snake venom peptide, on human cervical carcinoma (HeLa) cell‐ and B16‐F10 mouse melanoma cell‐induced platelet aggregation (TCIPA) in heparinized platelet‐rich plasma. TCIPA appears to play an important role in the development of certain experimental tumor metastases. Two ADP‐scavenging agents, apyrase (10 U/ml) and creatine phosphate (CP) (5 mM)/creatine phosphokinase (CPK) (5 U/ml) completely inhibited B16‐F10 TCIPA, but hirudin (5 U/ml) had no effect. In contrast, apyrase and CP/CPK did not inhibit HeLa TCIPA while hirudin completely inhibited it. Furthermore, HeLa cells initially induced platelet aggregation and then blood coagulation at a later stage. In addition, HeLa cells shortened, in a concentration‐dependent manner, the recalcification time of normal as well as factor VIII‐ and IX‐deficient human plasma, but did not affect the recalciflcation time of factor VII‐deficient plasma. This suggests that HeLa TCIPA occurs via activation of the extrinsic pathway, probably owing to tumor cell expression of tissue factor‐like activity. HeLa cell‐induced thrombin generation was confirmed by detection of amidolytic activity towards a chromogenic substrate, S‐2238 (H‐D‐Phe‐Pip‐Arg‐p‐NA). Triflavin and GRGDS inhibited, in a dose‐dependent manner, TCIPA caused by either cell line. On a molar basis, triflavin was 10,000–30,000 times more potent than GRGDS in this regard. Moreover, monoclonal antibodies raised against glycoprotein (GP) IIb/IIIa complex (i.e., 7E3 and AP2) and against GP Ib (i.e., AP1) completely inhibited HeLa TCIPA. 7E3 and AP2 inhibited B16‐F10 TCIPA by up to 80% whereas AP1 showed only 30% inhibition of B16‐F10 TCIPA. In conclusion, the inhibitory effect of triflavin on HeLa and B16‐F10 TCIPA may be mediated principally by the binding of triflavin to the fibrinogen receptor associated with GP IIb/IIIa complex on the platelet surface. However, GP Ib is also involved in HeLa TCIPA as thrombin formation is the key factor in triggering platelet aggregation caused by HeLa cells.
Comparative Immunohistochemical Studies of p53 and Proliferating Cell Nuclear Antigen Expression and Argyrophilic Nucleolar Organizer Regions in Pancreatic Duct Cell Carcinomas
Authors: Suzuki Tadamichi , Takano Yasuo
Published: August 2005

Thirty‐eight cases of pancreatic duct cell carcinoma were examined for p53 expression and proliferating cell nuclear antigen (PCNA) by enhanced immunohistochemistry, as well as for changes in numbers of argyrophilic nucleolar organizer regions (AgNORs). Fifteen cases (39.5%) showed p53 overexpression, which tended to increase in proportion to the histopathological grading of malignancy. However, tumor stage and lymph node status were not correlated to p53 overexpression. PCNA labeling index (LI) increased with both histologically malignant grading and pathological stage, but was not correlated with lymph node status. The expressions of p53 and PCNA thus did not necessarily reflect the degree of malignant development. In contrast, AgNOR number showed statistically significant correlations with these three indicators of malignancy. A comparative analysis of p53, PCNA LI and AgNOR number showed overexpression of p53 to be correlated to PCNA LI and essentially unrelated to AgNOR number. The present results thus indicate a close relation between p53 and PCNA, while AgNORs appear to be regulated separately from either of them.
Enhanced Antitumor Activity and Reduced Toxicity of 1,3‐Bis(2‐chloroethyl)‐1‐nitrosourea Administered in Lipid Microspheres to Tumor‐bearing Mice
Authors: Takenaga Mitsuko , Igarashi Rie , Tsuji Hiroaki , Mizushima Yutaka
Published: August 2005

Stable lipid microspheres (LM) and lipid nanospheres (LN) with average diameters of 200 nm and 50 nm, respectively, were used to encapsulate an lipophilic antitumor agent, 1,3‐bis(2‐chloroethyl)‐1‐nitrosourea (BCNU). LM and LN containing BCNU (lipo BCNU and s‐lipo BCNU, respectively) were prepared by homogenizing a soybean oil solution of BCNU with egg yolk lecithin, and their antitumor activity via the intravenous route was tested against L1210 leukemia in mice and compared with that of BCNU dissolved in saline. Both lipo‐BCNU and s‐lipo BCNU showed significantly enhanced antitumor activity with reduced toxicity, when compared with the corresponding doses of BCNU alone. These results suggest that LM and LN may be suitable carriers for lipophilic antitumor agents and may enhance their efficacy.
Comparison of Reversibility of Rat Forestomach Lesions Induced by Genotoxic and Non‐genotoxic Carcinogens
Authors: Kagawa Masataka , Hakoi Kazuo , Yamamoto Atsushi , Futakuchi Mitsuru , Hirose Masao
Published: August 2005

Reversibility of forestomach lesions induced by genotoxic and non‐genotoxic carcinogens was compared histopathologically. Groups of 30 to 33 male F344 rats were given dietary 0.1% 8‐nitroquinoline, dietary 0.4–0.2% 2‐(2‐furyl)‐3‐(5‐nitro‐2‐furyl)acrylamide, an intragastric dose of 20 mg/kg body weight N‐methyl‐N′‐nitro‐N‐nitrosoguanidine once a week, or 20 ppm N‐methylnitrosourethane in the drinking water as a genotoxic carcinogen, or 2% butylated hydroxyanisole, 2% caffeic acid, 2% sesamol or 2% 4‐methoxyphenol in the diet as a non‐genotoxic carcinogen for 24 weeks. Ten or 11 rats in each group were killed at week 24. Half of the remainder were maintained on basal diet alone for an additional 24 weeks and the other half were given the same chemical for 48 weeks, and then killed. Forestomach lesions induced by genotoxic carcinogens did not regress after removal of carcinogens. In contrast, simple or papillary hyperplasia (SPH), but not basal cell hyperplasia (BCH), induced by non‐genotoxic carcinogens clearly regressed after cessation of insult. SFH labeling indices in the non‐genotoxic carcinogen‐treated cases decreased after removal of the carcinogenic stimulus whereas BCH values were low irrespective of treatment. Atypical hyperplasia (AH), observed at high incidences in rats treated with genotoxic carcinogens, was also evident in animals receiving non‐genotoxic agents, even after their withdrawal, albeit at low incidences. AH labeling indices remained high even without continued insult. These results indicate that even with non‐genotoxic carcinogens, heritable alterations at the DNA level could occur during strong cell proliferation and result in AH development. This putative preneoplastic lesion might then progress to produce carcinomas.
Leukemic Cell Lysis by Activated Human Macrophages: Significance of Membrane‐associated Tumor Necrosis Factor
Authors: Nakabo Yukiharu , Harakawa Nari , Yamamoto Kohkichi , Okuma Minoru , Uno Kazuko , Sasada Masataka
Published: August 2005

In this study, we analyzed the mechanism(s) of leukemic cell lysis by human macrophages. Peripheral blood monocyte‐derived macrophages were activated with recombinant interferon‐γ and lipopoly‐saccharide and their lytic activity against two leukemic cell lines (K562 and HL‐60 cells) was assessed by an 111In releasing assay. Activated macrophages lysed these leukemic cells, and the lytic activity against leukemic cells was almost completely inhibited by anti‐tumor necrosis factor (TNF) antibody. The macrophage‐lysate prepared from activated macrophages also exhibited significant lytic activity against leukemic cells; this lytic activity was inhibited by anti‐TNF antibody. The leukemic cells that we used for the cytotoxicity assays were resistant to recombinant TNF. The culture supernatant of activated macrophages did not show any lytic activity. These findings suggest that cell‐associated TNF plays a role in macrophage‐mediated cytotoxicity against leukemic cells.
Chemical Modification by Polyethylene Glycol of the Anti‐tumor Enzyme Arginine Deiminase from Mycoplasma arginini
Authors: Takaku Haruo , Misawa Satoru , Hayashi Hideya , Miyazaki Kaoru
Published: August 2005

Ammo acid‐degrading enzymes are known to inhibit the growth of tumor cells in culture by depleting amino acids in the medium. Here we demonstrate that arginine deiminase (EC 3.5.3.6) from Mycoplasma arginini had stronger growth‐inhibitory activity against all 4 kinds of tumor cell lines tested than L‐asparaginase and arginase, which are well‐known anti‐tumor enzymes. Next, chemical modification of the arginine deiminase molecule with polyethylene glycol was shown to enhance its potency as an anti‐tumor enzyme. The percentage of modified amino groups per molecule was estimated to be 51% of the total amino groups, and the average molecular weight was estimated to be about 400,000 by gel‐filtration HPLC. The enzymic activity of the modified enzyme was 25.5 units/mg protein, which was equivalent to 57% of that of the native enzyme. The modified enzyme strongly inhibited growth of a mouse hepatoma cell line, MH134, at a concentration of more than 10 ng/ml, showing almost the same dose‐response curve as the native enzyme. When a bolus of 5 units of the modified enzyme was intravenously injected into male BDF1 mice, L‐arginine in the blood completely disappeared within 5 rain, and remained undetectable for more than 8 days. On the other hand, in the case of bolus injection of the same number of units of native enzyme, the plasma L‐arginine level recovered up to 66% of the control level at 8 days. These results suggest that this modified enzyme has a longer plasma clearance time and may be more effective as a new anti‐tumor agent than the native enzyme.
Chromosomal Assignment of the Gene for Protein Tyrosine Phosphatase HPTPδ
Authors: Hasegawa Kiminori , Ariyama Takeshi , Inazawa Johji , Mizuno Kazuya , Ogimoto Mami , Katagiri Tatsuo , Yakura Hidetaka
Published: August 2005

Protein tyrosine phosphatase (PTP) negatively regulates the effect of protein tyrosine kinases and is implicated in the regulation of a variety of biological phenomena such as cell activation, differentiation and neoplastic transformation. To gain insight into the role of PTPs, we cloned the human receptor‐type FTP gene and assigned the chromosome harboring the gene for HPTPδ by using DNAs from human‐mouse hybrid cell lines and by fluorescence in situ hybridization. The results clearly demonstrated that HPTPδ gene maps to human chromosome 9p24.
Prognostic Significance of Selected Lifestyle Factors in Urinary Bladder Cancer
Authors: Wakai Kenji , Ohno Yoshiyuki , Obata Kohji , Aoki Kunio
Published: August 2005

To examine the prognostic significance of lifestyle factors in urinary bladder cancer, we conducted a follow‐up study of 258 incident bladder cancer patients, who were originally recruited in a case‐control study in metropolitan Nagoya. Information on individual survivals was obtained from the computer data‐file of the tumor registry of the Nagoya Bladder Cancer Research Group. Univariate analyses revealed significant associations of 5‐year survivorship with educational attainment, marital status, drinking habits and consumption of green tea in males, and age at first consultation, histological type and grade of tumor, stage and distant metastasis in both sexes. After adjustment for age, stage, histology (histological type and grade) and distant metastasis by means of a proportional hazards model, drinking of alcoholic beverages was significantly associated with the prognosis of bladder cancer in males. Its adjusted hazard ratio was 0.46 (95% confidence interval: 0.26–0.79), favoring patients who had taken alcoholic beverages. In detailed analysis, ex‐drinkers and all levels of current drinkers demonstrated hazard ratios smaller than unity, although no clear dose‐response relationship was detected. No prognostic significance was found for such lifestyle factors as smoking habit, uses of artificial sweeteners and hairdye, and consumption of coffee, black tea, matcha (powdered green tea) and cola.
Progression of a Weakly Tumorigenic Mouse Fibrosarcoma at the Site of Early Phase of Inflammation Caused by Plastic Plates
Authors: Okada Futoshi , Hosokawa Masuo , Hamada Jun‐ichi , Hasegawa Junji , Mizutani Masatoshi , Takeichi Noritoshi , Kobayashi Hiroshi
Published: August 2005

To elucidate tumor progression‐enhancing factor(s), we examined the effects of host inflammation and host immunological status on in vivo tumor progression. One × 104 cells of QR clones (QR‐32, ‐20 and ‐18), regressor tumor clones of 3‐methylcholanthrene‐induced fibrosarcoma, were unable to grow when injected s.c. into C57BL/6 mice in cell suspension form. However, QR clones grew and were lethal when s.c. implanted, attached to plastic plates. Furthermore, the tumor lines (QRpP) obtained from the tumors which had arisen from the plate‐attached QR‐32 clone cells no longer required plastic plates for their growth in normal mice, and had acquired stable malignant phenotypes. Although QR‐32 cells became lethal when injected at the site of plastic plate implantation 1, 5 and 10 days before tumor injection, few tumors developed when plastic plates had been implanted 20 or 30 days before tumor injection. We established culture clones from the tumors arising in normal mice and mice immunosuppressed by irradiation. Clones derived from the tumors which had arisen in normal mice after implantation with plastic plates were lethal when re‐implanted in normal mice (71%). On the other hand, clones derived from the tumors that arose in irradiated mice with or without plastic plates were lethal in only a few normal mice, when re‐implanted (20 and 8%, respectively). These results indicate that QR clone cell progression is enhanced by the early phase of inflammation at the site of plastic plate implantation and that the progression‐enhancing activity of co‐implantation with a plastic plate is inhibited by previous whole‐body irradiation of hosts.
Number of Simultaneously Expressed Enzyme Alterations Correlates with Progression of N‐Ethyl‐N‐hydroxyethylnitrosamine‐induced Hepatocarcinogenesis in Rats
Authors: Yamaguchi Shuji , Hakoi Kazuo , Ozaki Keisuke , Kato Toshio , Tiwawech Danai , Nagao Shizuko , Takahashi Hisahide , Matsumoto Kazuyuki , Tsuda Hiroyuki
Published: August 2005

Preneoplastic and neoplastic liver cell lesions, induced by EHEN (N‐ethyl‐N‐hydroxyethylnitrosamine) in rats, were investigated to establish the numbers of simultaneously expressed altered enzyme phenotypes within the lesion cells. The lesions were divided into 5 classes on the basis of altered expression in one or more of the following 5 enzymes: glutathione S‐transferase placental form, glucose‐6‐phosphate dehydrogenase, glucose‐6‐phosphatase, adenosine triphosphatase, and γ‐glutamyl transpeptidase. Class 1 lesions contained cells expressing one altered enzyme. Similarly, class 2, 3, 4 and 5 lesions had cells simultaneously expressing 2, 3, 4, and 5 enzyme alterations, respectively. Four histopathological categories of lesions, ACF (altered cell foci) (274 lesions), HN (hyperplastic nodules) (47 lesions), HCC (hepatocellular carcinomas) (99 lesions) and THC (transplanted hepatocellular carcinomas) (5 lesions) were studied. Proliferation potential was assessed in terms of 5‐bromo‐2′‐deoxyuridine (BrdU) incorporation. The distribution profiles of classes 1 to 5 showed a clear reciprocal change from low class (1 to 2 enzymes) predominance in ACF to high class (4 to 5 enzymes) predominance in HN. Increase of BrdU labeling indices was clearly correlated with progression from HN to HCC. Only a small population of class 5 ACF showed a high BrdU labeling index, indicating particular potential for further development. Thus, the stages of EHEN‐induced neoplasia were found to be characterized by gradual increase in the number of altered enzyme phenotypes, with acquisition of proliferative potential being associated with further progression towards malignant conversion.