Biomedical subjects

M Tatematsu

Publications and source records attributed to M Tatematsu.

At least 91 records · Page 5Linked to original sources

PubMed1997

Highly metastatic hepatocellular carcinomas induced in male F344 rats treated with N-nitrosomorpholine in combination with other hepatocarcinogens show a high incidence of p53 gene mutations along with altered mRNA expression of tumor-related genes.

The carcinogenic and metastatic processes are thought to consist of a sequence of steps, and animal models featuring highly metastatic lesions are clearly necessary to allow analysis of the whole process of transformation from preneoplastic changes to high grade metastatic tumors, and to access effectiveness of therapeutic treatments of advanced cancers in vivo. The purpose of the present study was to establish a model and to screen for reported genetic alterations in induced lesions. In the present study, it was confirmed that lung metastasis of hepatocellular carcinomas (HCCs) induced in male F344 rats by N-nitrosomorpholine (NNM), given in the drinking water at a dose of 120 ppm for 24 weeks, was significantly enhanced by additional carcinogenic pretreatments and that a single i.p. injection of 100 mg/kg body weight N-diethylnitrosamine (DEN) alone was sufficient for that purpose. Molecular biological analyses of the induced lesions revealed point mutations in the p53 gene in 60.9% of HCCs, and elevated expression of mRNAs for p53, c-myc, c-fos, TGF-alpha, TGF-beta1, alpha-fetoprotein, GST-P, and GGT, and decreased mRNA expression of EGF and EGFR in HCCs when compared to controls. No obvious association of gene alterations with metastatic potential of primary tumors was found except for an increase in the incidence of p53 mutations. Since the process of metastasis is thought to be sequential and selective, further comparative analysis of metastatic and primary lesions should clarify the mechanisms involved in the multi-step process of metastasis.

Animals↗

PubMed1997

Induction of invasive squamous cell carcinomas in the forestomach of (C3H x MSM)F1, MSM, and C3H mice by N-methyl-N-nitrosourea and mutational analysis of the H-ras and p53 genes.

Genetic analysis of tumors developing in F1 hybrids between genetically separate strains of mice makes it possible to search for loss of heterozygosity (LOH), information on which provides clues to finding tumor-suppressor genes. For this purpose, however, reproducible carcinogenic conditions for the organ of interest need to be first determined. In the present study, a forestomach model of squamous cell carcinomas (SCCs), induced in (C3H x MSM)F1 mice by N-methyl-N-nitrosourea (MNU), was established and mutational changes in the H-ras and p53 genes were examined in tumors. Male (C3H x MSM)F1, MSM and C3H mice were given MNU by i.g. intubation once a week at a dose of 0.03 mg/g body weight for 10 weeks, then kept without further treatment. At experimental weeks 38-46, markedly invasive SCCs were observed in the forestomach at incidences of 9/14 (64.3%), 9/16 (56.3%), and 2/10 (20.0%), respectively. In the three strains of mice, DNA analysis of SCCs by PCR-SSCP analysis followed by direct DNA sequencing revealed low incidences of point mutations in the H-ras (4/20, 20%) and p53 (3/20, 15%) genes. The results demonstrate the usefulness of the present animal experimental protocol for induction of high grade SCC in the forestomach of (C3H x MSM)F1 mice, and suggest the possibility that point mutations in the H-ras or p53 genes may play some role in pathways leading to the development of such lesions.

Animals↗

PubMed1997

Histochemical and immunohistochemical study of human gastric carcinoma differentiation with special reference to supplementary role for endosonography in evaluating depth of invasion.

The aim of this study was to evaluate the usefulness of gastric and intestinal epithelial phenotypic expression of gastric cancer cells, shown by mucin histochemical staining (paradoxical concanavalin A, galactose oxidase Schiff [GOS] and sialidase-GOS) and immunohistochemical reactivity (pepsinogens, SH-9, and TKH-2), as an adjunct to the assessment of depth of invasion of gastric carcinomas by endosonography (ES). In 110 resected adenocarcinomas, the proportion of intestinal-type cells increased with progression, as assessed by depth of invasion. The coincidence rate for gastric and intestinal phenotypic expression in biopsied and resected specimens was 96.3%. The positive predictive value of assessment of depth of invasion by ES was 73%. A low positive predictive value (45%) was achieved with type II-3 cases (according to our classification). However, the predictive value improved to 68% when depth of invasion was evaluated as the submucosal layer or deeper in cases in which more than 10% of cancer cells were of intestinal-type, although statistical analysis showed no significant difference between these predictive values. The sensitivity of diagnosis of submucosal invasion by cell differentiation in the type II-3 cases was significantly higher than that for the other types (89.5% versus 59.1%; P = 0.037). Phenotypic expression in biopsied specimens of gastric carcinomas proved helpful for evaluating the depth of invasion of gastric carcinoma by ES.

Adenocarcinoma↗

PubMed1997

Reciprocal control of colon-specific sulfomucin and sialosyl-Tn antigen expression in human colorectal neoplasia.

Histochemical reports claim that sulfomucins decrease and sialylated mucins increase during colon carcinogenesis. We examined the expression of colon-specific sulfomucins and sialosyl Tn antigen (STN) in normal small intestine, normal colorectal mucosa and colorectal tumours at different stages of progression immunohistochemically, using MAb 91.9H specific for colonic sulfomucins and MAb TKH-2 for STN. No expression of sulfomucins recognized by MAb 91.9H was found in normal small intestine, whereas STN staining was pronounced. The converse was the case in normal colorectal mucosa. Sulfomucins were still found in adenomas, but the amounts decreased with depth of invasion in cancers (P < 0.001). In contrast, no STN could be detected in benign lesions, but staining became increasingly evident with invasion (P < 0.001). This reciprocal control of expression of colon-specific sulfomucins and STN evident in tumour progression indicates that the mucous phenotype shifts from the colonic to the small intestinal type.

Adenoma↗

PubMed1997

Intestinalization of gastric signet ring cell carcinomas with progression.

Recent developments in mucin histochemistry and immunohistochemistry have made reliable determination of the gastric and intestinal phenotypes of gastric carcinoma cells possible. Phenotypic expression changes from gastric epithelial cell type to intestinal epithelial cell type with the growth of gastric tumours in experimental animals. We studied cell differentiation in gastric signet ring cell carcinomas with progression in 203 surgically obtained specimens. The results showed that the proportion of gastric phenotype carcinomas, in which over 90% of the tissue consists of gastric epithelial cell type cells, decreases with the depth of invasion. The proportion of mixed phenotype carcinomas (between 10% and 90% of the tissue made up of gastric and/or intestinal epithelial cell type cells) increases. The intestinal phenotype (over 90% intestinal epithelial cell type carcinoma cells) was found in four carcinomas (about 2%) involving the serosa. No clear relationship was evident between phenotypic expression of carcinoma cells and the degree of intestinal metaplasia of the surrounding mucosa. Progression of gastric signet ring cell carcinomas is associated with a phenotypic shift from gastric to intestinal type expression.

Carcinoma, Signet Ring Cell↗

PubMed1997

Proliferation, differentiation and morphogenesis of fetal rat glandular stomach transplanted under the kidney capsule of syngeneic hosts.

Undifferentiated glandular stomach tissue fragments from 16.5-day fetal rats were transplanted under the kidney capsule of syngeneic adult rats, and the proliferation, differentiation and morphogenesis of the transplanted tissues were investigated. Gastric epithelial cells began to invaginate 3-4 days after the transplantation and immature glands were formed after 1 week. During the period, there was a gradual increase in the expression of pepsinogen and cathepsin E, markers of cytodifferentiation of the stomach epithelia, both at protein and mRNA levels. Cathepsin E was weakly expressed in undifferentiated gastric epithelial cells at 16.5 days of gestation, and a higher level of the expression was observed in differentiated epithelia of the transplants. In contrast, the pepsinogen-producing cells first appeared around days 3-4 after transplantation and gradually increased in number to about 30% of the epithelial cells and became localized at the bottom of the gland. During the period of the experiment up to 1 month, the pepsinogen-producing cells were all positive for class III mucin and cathepsin E, indicating the immature character of these cells. In addition, no parietal cells were observed. When the tissue fragments were transplanted into adrenalectomized animals, the epithelial differentiation and morphogenesis was suppressed, but its proliferation was enhanced. The observed changes were reversed by hydrocortisone replacement. These results suggest that the development of the 16.5-day fetal stomach is regulated intrinsically to a certain extent by the genetic program of the cells involved and various gastric functions develop in the absence of luminal stimulation, stage-specific systemic hormonal change, neuronal regulation or other systemic influences, and that glucocorticoids modulate the developmental program of the fetal stomach tissues.

Adrenalectomy↗

PubMed1997

Genetic instability and p53 mutations in metastatic foci of mouse urinary bladder carcinomas induced by N-butyl-N-(4-hydroxybutyl)nitrosamine.

In a variety of human malignancies, alteration of the p53 tumour suppressor gene is known as a significant indicator of late progression events including invasion and metastasis, with a possible close relationship to genetic instability. Mutational analysis of the p53 and H-ras genes was performed for 10 pairs of N-butyl-N-(4-hydroxybutyl)nitrosamine-induced invasive mouse urinary bladder carcinomas and metastatic foci. p53 Mutations were found in nine of 10 (90%) primary carcinomas and seven of 10 (70%) metastatic foci. A total of eight p53 mutations in primary carcinomas were common in metastatic foci in six pairs. Additional p53 or H-ras mutations which were not identified in the primary carcinomas were found in three metastatic foci. Evaluation of the allelic distribution of the p53 mutations using RT-PCR, PCR and subcloning, further indicated possible intra-tumour genomic heterogeneity or excess copy numbers of the p53 gene due to genetic instability. Overall, p53 alterations were frequent in mouse urinary bladder carcinomas demonstrating progression. The results suggest that genetic instability might underlie generation of additional genetic alterations in this animal model.

Animals↗

PubMed1997

Reduction of glutathione S-transferase P-form mRNA expression in remodeling nodules in rat liver revealed by in situ hybridization.

Glutathione S-transferase P-form (GST-P) mRNA levels and distribution were sequentially analyzed by in situ hybridization histochemistry (ISH) in rat livers during and after induction of preneoplastic foci and nodules in the Solt-Farber model. Dot blot analysis showed GST-P transcripts in the liver to be elevated coincidental with the development of GST-P-positive lesions. GST-P ISH indicated that the majority of early foci and some of the resultant lesions showed uniformly high levels of GST-P mRNA. However, the majority of foci and nodules after completion of the selection regimen exhibited a progressive loss of staining for GST-P mRNA. Similar results were obtained for gamma-glutamyltransferase (GGT) transcripts, indicating that phenotypic reversion is controlled by factors operating at the level of gene expression in both cases. Expression of GST-P mRNA was high in all hepatocellular carcinoma samples, whereas the levels of GGT transcripts varied considerably, so that the two enzymes showed a degree of independence in their regulation. The present data for transcription suggest that GST-P is a stable marker of preneoplastic and neoplastic cells, not only at the protein but also at the mRNA level, throughout hepatocarcinogenesis in the rat. The reason why transcription of GST-P mRNA is switched off as part of the reversion to a normal organization remains to be elucidated.

2-Acetylaminofluorene↗

PubMed1997

Denervation promotes the development of cancer-related lesions in the gastric remnant.

Innervation of the gastric mucosa plays an important role in its defense mechanism. In a previous study, gastrectomy with denervation promoted tumorigenesis in the gastric body in rats after administration of a carcinogenic agent. In this study we investigated the induced gastric mucosal changes from the viewpoint of mucin histochemistry. Gastrectomy with denervation promoted the development of intestinal metaplasia, dysplasia, and carcinoma in the gastric body. Proliferating cell nuclear antigen labeling indexes as a marker for cell kinetics were significantly elevated in the denervated group. Analysis of mucin histochemistry by staining with paradoxical concanavalin A (PCA) and galactose oxidase-Schiff (GOS), which are markers for expression of the gastric phenotype, revealed that these mucins were positive in submucosal adenocystic proliferation and carcinoma at the anastomotic site. Conversely, in the gastric body these mucins disappeared with progression of dysplasia, and carcinoma cells contained neither PCA- nor GOS-positive mucins. These results suggest that there are two different processes of carcinogenesis in the gastric remnant, depending on the location, and that denervation of the remnant gastric mucosa promotes the development of cancer-related lesions in the gastric body.

Animals↗

PubMed1997

Dose-dependent promoting effects of catechol on glandular stomach carcinogenesis in BALB/c mice initiated with N-methyl-N-nitrosourea.

The effects of catechol administration in the diet on stomach carcinogenesis in mice after initiation with N-methyl-N-nitrosourea (MNU) in the drinking water were investigated in a development trial for a new experimental protocol. Male 6-week-old BALB/c mice were given MNU in the drinking water intermittently for a total of three one-week periods, with one-week intervals, at the concentration of 120 ppm (groups 1 and 2). Groups 3 and 4 served as non initiated controls. From week 7, groups 1 and 3 were divided into three subgroups and the mice were fed on diet containing 0.05% (groups 1a and 3a), 0.2% (groups 1b and 3b), 08% (groups 1c and 3c) or 0% (groups 2 and 4) catechol for 29 weeks. At week 20, appreciably enhanced development of pepsinogen 1-altered pyloric glands was noted in all catechol-treated groups, in a partially dose-dependent manner (12.8 +/- 12.5, 13.8 +/- 11.7, and 24.0 +/- 12.7/100 pyloric glands respectively, for groups 1, 2 and 3). The incidences of adenomas (groups 1, 2 and 3) were also increased. At week 35, dose-dependent induction of adenocarcinomas in groups 1 (3/19), 2 (3/19) and 3 (14/20) was evident. In addition, the depth of invasion of the adenocarcinomas was enhanced by catechol in a dose-dependent manner, though the histological type was not influenced. Thus, the administration of catechol in the diet strongly enhanced the preneoplastic and neoplastic lesions in mouse glandular stomach induced by MNU in the drinking water, in a dose-dependent manner.

Adenocarcinoma↗

PubMed1997

Dose-dependent induction of both pepsinogen-altered pyloric glands and adenocarcinomas in the glandular stomach of C3H mice treated with N-methyl-N-nitrosourea.

The dose-response relation for the appearance of pepsinogen isozyme 1 (Pg 1)-altered pyloric glands (PAPG) and the related induction of adenocarcinomas were examined in male C3H mice given N-methyl-N-nitrosourea (MNU) in their drinking water at the concentration of 120 ppm (group 1), 60 ppm (group 2), 30 ppm (group 3) or 0 ppm (group 4) for 30 weeks and then normal tap water. Animals were killed at weeks 10, 30 and 42. Adenomatous hyperplasias and adenocarcinomas were noted from week 30 and their induction was dose-dependent at week 42. Almost all cells of pyloric gland cell type in those lesions had little or no immunohistochemically demonstratable Pg 1 content, as was also the case for the cells in PAPG, whose numbers per 100 normal-appearing pyloric glands were found to be MNU dose-dependent at all experimental time points. The numbers of PAPG at week 10 significantly correlated with the incidences of adenomatous hyperplasias and adenocarcinomas at week 42. Investigation of proliferation by immunohistochemical detection of bromodeoxyuridine (BrdU) labeling in the PAPG at week 10 demonstrated elevation (P < 0.05) as compared to normal pyloric glands. Intestinal metaplasia was not a feature in the present experiment and the results suggest that in mice, PAPG might be a preneoplastic lesion involved in gastric chemical carcinogenesis.

Adenocarcinoma↗

PubMed1997

Rare occurrence of ras and p53 gene mutations in mouse stomach tumors induced by N-methyl-N-nitrosourea.

The incidence of point mutations of H-, K- and N-ras and p53 oncogenes in male BALB/c mouse stomach tumors induced with N-methyl-N-nitrosourea (MNU) was examined by direct sequencing and PCR single-strand conformation polymorphism (PCR-SSCP). A mutation of GGT to AGT at K-ras codon 12 was found by SSCP in one adenocarcinoma from a total of 19 specimens including 5 adenocarcinomas, 9 adenomatous hyperplastic regions, 1 squamous cell carcinoma and 4 normal-like stomach regions from 4 mice. No mutations were detected by direct sequencing of H-, K- and N-ras oncogenes at exons 1 (codons 12 and 13) and 2 (codon 61) in a total of 26 specimens comprising 10 adenocarcinomas, 10 adenomatous hyperplastic regions, 2 squamous cell carcinomas and 4 normal-like stomach regions from 6 mice. No mutations were detected by direct sequencing of p53 oncogene at exons 5, 6, 7 and 8 in a total of 30 specimens including 13 adenocarcinomas, 8 adenomatous hyperplastic regions, 2 squamous cell carcinomas, 1 papilloma and 6 normal-like stomach regions from 7 mice. These results suggest that ras and p53 oncogenes do not play a role in mouse stomach carcinogenesis induced by MNU.

Adenoma↗

PubMed1997

Sparse distribution of hepatocyte growth factor-producing cells inside hepatocellular foci in rats treated with hepatocarcinogens.

The distribution of hepatocyte growth factor (HGF)-synthesizing cells in rat liver during development of glutathione S-transferase P form (GST-P)-positive nodules after diethylnitrosamine initiation followed by promotion with 2-acetylaminofluorene plus partial hepatectomy (PH) was investigated using in situ hybridization. HGF-producing cells were non-parenchymal in nature, and were suspected to be mainly of Kupffer type. They were mostly located outside GST-P-positive lesions, in the surrounding parenchyma. In the oval cell proliferation phase 1 week after PH, they increased and they were mainly localized around the portal triads. It is concluded that HGF is directly involved in an endogenous paracrine growth pathway controlling proliferation in oval cells and in normal, but not GST-P-positive, hepatocytes.

2-Acetylaminofluorene↗

PubMed1997

Detection of carcinoembryonic antigen-expressing free tumor cells in peritoneal washes from patients with gastric carcinoma by polymerase chain reaction.

Cytological examination of peritoneal washes is a useful predictor of peritoneal recurrence in gastric carcinoma patients. In the present study, even more sensitive detection of free cancer cells could be achieved through amplification of carcinoembryonic antigen (CEA) mRNA by means of the reverse transcriptase-polymerase chain reaction (RT-PCR). CEA was first confirmed to be present in all the gastric cancer cell lines examined, irrespective of the differentiation degree, and absent in blood and mesothelium, indicating the specificity of this approach for detection of carcinoma cells in peritoneal lavage fluid. In sensitivity tests, CEA RT-PCR proved to be capable of detecting 10 carcinoma cells per sample. Peritoneal washes of 15 of 48 gastric carcinoma patients, including all 10 patients with positive cytology results, proved positive for CEA mRNA. None of the 5 patients with benign disease was positive. Moreover, a close association with the depth of cancer invasion was established. The results indicate that the assay is more sensitive for detection of free carcinoma cells in the peritoneal cavity than conventional cytology. This is the first study to suggest the feasibility of the RT-PCR method for prediction of peritoneal recurrence in gastric cancer patients.

Adult↗

PubMed1997

Gastric and intestinal mixed and solely intestinal types of intestinal metaplasia in the human stomach.

To generate a novel understanding of intestinal metaplasia (IM) on the basis of cellular differentiation status, a total of 132 gastric surgical specimens were studied using gastric and small intestinal cell markers by mucin histochemical and immunohistochemical techniques. The cases were divided into two types: (i) gastric and intestinal (GI) mixed type; and (ii) solely intestinal (I) type, with the reference to the presence of gastric and/or intestinal cell markers. The GI mixed type was subdivided into six subtypes: (I) a subtype consisting of surface mucous (Su), pyloric gland (Py), intestinal absorptive (Ab), and goblet (Go) cells, but lacking Paneth (Pa) cells, GI(Pa-); (ii) a GI(Pa-) subtype without Py cells, GI(Py-, Pa-); (iii) a GI(Pa-) subtype without Su cells, GI(Su-, Pa-); (iv) a GI(Su-, Pa-) subtype with Pa cells, GI(Su-, Pa+); (v) a GI(Pa-) subtype with Pa cells, GI(Pa+); and (vi) a GI(Pa+) subtype without Py cells, GI(Py-, Pa+). The I type was subdivided into: (i) a subtype consisting of cells with Ab and Go cells, I(Pa-); and (ii) a I(Pa-) subtype with Paneth cells, I(Pa+). The GI mixed subtypes, except for the GI(Py-, Pa-) and GI(Py-, Pa+), were characterized by intestinalized gastric pits connected with underlying pyloric glands. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA) revealed a common proliferative cell zone between the two. The GI mixed type, especially the GI(Pa-) subtype, predominated in the pyloric mucosa, while the I type was most frequent in the fundic region, suggesting that the pathogenesis of IM differs between these two locations. The results of the study confirm that IM is an abnormal and unstable differentiation status between the stomach and small intestine.

Adult↗

PubMed1997

Hydrolytic profile for ester- or amide-linkage by carboxylesterases pI 5.3 and 4.5 from human liver.

Carboxylesterases (EC 3.1.1.1) from human liver were purified using Q-Sepharose, Sephadex G-150, isoelectrofocusing and Con A-Sepharose. The calculated molecular mass of the pI 5.3 enzyme was 120 kDa and 61 kDa from the results of Sephadex G-150 gel filtration and SDS-polyacrylamide gel electrophoresis (PAGE), respectively, suggesting that this enzyme is a dimer. On the other hand, carboxylesterase pI 4.5, with a molecular mass of 64 kDa, was a monomer. The activities of both enzymes were inhibited by typical serine enzyme inhibitors. Amino acid sequence analysis of the purified enzymes pI 5.3 and 4.5 showed high homology with rabbit carboxylesterase form 1 and 2, respectively. The results also suggested that carboxylesterase pI 5.3 is identical to the deduced amino acid sequence from cDNA for HU1, and that carboxylesterase pI 4.5 is identical to the deduced amino acid sequence from the cDNA registered as human carboxylesterase (hCE-2) in GenBank. We first purified carboxylesterase pI 4.5 and investigated its hydrolytic activity upon various drugs. The two enzymes differed in substrate specificity. Prodrugs of angiotensin-converting enzyme inhibitors, such as delapril and imidapril, were converted to active metabolites by carboxylesterase pI 5.3, but not by carboxylesterase pI 4.5. The hydrolysis velocity of temocapril by carboxylesterase pI 5.3 was 12-fold faster than by carboxylesterase pI 4.5. In contrast, aspirin, oxybutynin and procaine were hydrolyzed by only carboxylesterase pI 4.5. We also found that an amide-linkage in drugs, except for that in aniracetam, was not a good substrate for the two enzymes. Consequently, carboxylesterases pI 5.3 and 4.5 may be involved in the metabolism of various drugs containing an ester-linkage.

Amino Acid Sequence↗

PubMed1997

[Molecular diagnostic detection of circulating tumor cells and their prognostic implications].

While not all circulating tumor cells survive, one could postulate that patients with circulating tumor cells might be candidates for adjuvant chemotherapy because of the risk of relapse. Recently, reverse transcriptase-polymerase chain reaction (RT-PCR) for the detection of circulating tumor cells has been suggested as a potential technique for staging of cancer. In malignant melanoma, the detection of circulating melanoma cells by tyrosinase RT-PCR correlated with the clinical stage of patients and was an independent prognostic factor for recurrence. A strong association was found between the detection of neuroblastoma cells in circulation by tyrosine hydroxylase RT-PCR with bone marrow micrometastasis. This method may be of use to identify early signs of relapse in disease-free patients. In prostatic cancer, the frequency of positivity for detection of circulating tumor cells in peripheral blood by PSA RT-PCR increased with tumor stages but a significant proportion of patients with metastatic disease were negative. The prognostic significance of the detection of tumor cell in blood in other epithelial tumors is not established and will require further long-term follow-up study.

Biomarkers, Tumor↗

PubMed1996

Effect of 2-chloro-4-methylthiobutanoic acid in a rapid bioassay for gastric carcinogens.

2-Chloro-4-methylthiobutanoic acid (CMBA, a mutagen from Japanese salted fish) at 15-500 mg/kg body weight induced several-fold increase in replicative DNA synthesis (RDS) (P < 0.05) after 80 min and 17 h, equivocal unscheduled DNA synthesis (UDS) after 80 min and necrosis 80 min after its administration in the stomach pyloric mucosa of F344 and ACI male rats. A positive control, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 50 mg/kg body weight), induced RDS, UDS and erosion. However, the negative control L-methionine (500 mg/kg body weight) did not display any effect. The results suggest possible tumor-initiating and -promoting activity of CMBA but at a lower potency than that of MNNG.

Animals↗