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Biomedical subjects

E Tsuchiya

Publications and source records attributed to E Tsuchiya.

At least 55 records · Page 3Linked to original sources
PubMed1995

Isolation of a candidate tumor suppressor gene on chromosome 8p21.3-p22 that is homologous to an extracellular domain of the PDGF receptor beta gene.

We have isolated a candidate tumor suppressor gene from a 600-kb region on chromosome 8p21.3-p22 that is commonly deleted in sporadic hepatocellular carcinomas (HCC), colorectal cancers (CRC), and non-small cell lung cancers (NSCLC). As this gene encodes a protein of 375 amino acids that bears significant sequence similarity to the extracellular (ligand-binding domain of platelet-derived growth factor receptor beta, we have designated it PRLTS (PDGF-receptor beta-like tumor suppressor). Structural rearrangement involving this gene was found in a sporadic NSCLC. In addition, somatic missense and frame-shift mutations were found in two HCCs and one CRC. These findings indicate that inactivation of the PRLTS gene may play a significant role in development of some carcinomas.

Amino Acid Sequence↗
PubMed1995

Accumulation of genetic changes during development and progression of hepatocellular carcinoma: loss of heterozygosity of chromosome arm 1p occurs at an early stage of hepatocarcinogenesis.

To investigate cumulative genetic changes during development and progression of hepatocellular carcinoma (HCC), we examined DNAs isolated from 104 tumors for loss of heterozygosity (LOH) at 13 loci on six chromosomal arms and for an increase of copy number ("multiplication") of alleles on 8q, using polymorphic microsatellite markers. A comparison of genetic features with clinicopathological stages of these tumors revealed that LOH on 1p had occurred in tumors at an early stage or with a well-differentiated histological phenotype (8/26; 31%) as well as in tumors at more advanced stages. Genetic alterations on chromosome arms 4q, 8p, 8q, 13q, 16q, and 17p were more often observed in tumors of more advanced stages and poorer differentiation grades. When size was the criterion for comparison, LOH on 1p was observed frequently even in tumors smaller than 2 cm (6/16; 38%), whereas allelic losses on 16q were detected frequently only in larger tumors. These results suggest that the putative tumor suppressor gene(s) assumed to be located on 1p may be involved in an early step of carcinogenesis in liver tissue and that the other genetic alterations examined here may play important roles in progression of HCC.

Carcinoma, Hepatocellular↗
PubMed1995

High K-ras mutation rates in goblet-cell-type adenocarcinomas of the lungs.

Adenocarcinomas of the lungs show a variable histology. We have subclassified such lesions into five cell types: hobnail, columnar, polygonal, mixed and goblet cell types, and investigated their relationships with K-ras mutations. Codons 12, 13 and 61 of the K-ras gene in 120 surgically resected pulmonary adenocarcinomas were examined by the mutation-allele-specific amplification method. Point mutations were observed in 10% of the adenocarcinomas limited to K-ras codon 12 and the commonest base substitution (nine cases) was a G to T transversion. Of the five types, goblet cell lesions demonstrated the highest mutation index, which at 100% (6/6) was significantly different from that of all other cell types. No relationship between K-ras mutation and cigarette smoking was observed. From these findings, it appears that development of goblet-cell-type adenocarcinomas of the lung may involve different carcinogenic mechanisms from adenocarcinomas of other subtypes.

Adenocarcinoma↗
PubMed1995

The physiological roles of membrane ergosterol as revealed by the phenotypes of syr1/erg3 null mutant of Saccharomyces cerevisiae.

Ergosterol is a major sterol component of fungal plasma membranes. The effects of disrupting the Saccharomyces cerevisiae SYR1/ERG3 gene, which encodes sterol C-5 desaturase, an enzyme of ergosterol biosynthesis pathway, were markedly different for different S. cerevisiae strains and growth temperatures. The null mutation of SYR1 (delta syr1) in strain RAY-3A had only a slight effect on the growth rate at 28 degrees C. However, at this temperature, the same mutation caused poor growth in strain KA-311A and no growth in strain W303-1A. The delta syr1 disruptant of these strains were able to grow at 37 degrees C, as well as their parental strains. Moreover, the growth of the delta syr1 disruptant of W303-1A and KA-311A strains were severely inhibited at 16 degrees C. These results indicated that ergosterol is essential for growth at low temperatures, and the effects of the gene disruption are variable by the genetic background. The growth defect at low temperatures appeared to be due to the defect of tryptophan uptake in the delta syr1 mutants. The delta syr1 mutants were sensitive to a wide variety of drugs, chemicals, and ions, suggesting that yeast ergosterol is important as permeability barrier against various chemical stresses.

Antifungal Agents↗
PubMed1995

[Renal cell carcinoma in a patient with malignant lymphoma: a case report].

This is a case report of a 51-year-old male in the late stage of malignant lymphoma who presented with pathological fracture renal cell carcinoma secondary to metastatic. He underwent right nephrectomy followed by immunotherapy consisting of interferon alpha and some cytokines. According to his condition and extension of the disease, OK-432, interleukin-2 and interferon gamma were combined. He was also given irradiation to the bone metastases. He died of progressive disease 8 years and 6 months after the initiation of interferon alpha therapy. The autopsy revealed evidence of pancreatic involvement with renal cell carcinoma and malignant lymphoma as well. Malignant lymphoma also infiltrated into the mesentery and left femur. We reviewed other reports regarding multiple malignant tumors associated with renal cell carcinoma and discussed the occurrence of malignant lymphoma in renal cell carcinoma patients.

Carcinoma, Renal Cell↗
PubMed1995

Novel mechanism of resistance to paclitaxel (Taxol) in human K562 leukemia cells by combined selection with PSC 833.

A paclitaxel-resistant cell line, KPTA5, was established by co-selecting the parental erythroleukemic cell line K562 with stepwise increased concentrations of paclitaxel (Taxol) in the presence of the cyclosporin D analogue PSC 833 (2 microM), a potent modulator of the multidrug resistance phenotype. KPTA5 cells are 9-fold resistant to paclitaxel and taxotere, but do not exhibit significant resistance to Vinca alkaloids, etoposide, anthracyclines, antimetabolites, or alkylating agents. Doubling time and morphology were similar to the parental K562 cells. Reverse transcriptase-polymerase chain reaction (rt-PCR) analysis revealed no alterations in the expression of the mdr1 and MRP genes. Cellular paclitaxel accumulation was unchanged. Cell cycle analyses showed that at 20 nM there was a significantly higher proportion of K562 cells blocked in G2/M, in comparison with KPTA5 cells. In both cases, disruption of the mitotic spindles and the presence of multiple mitotic asters were comparable but occurred at lower paclitaxel concentrations in K562 cells than in KPTA5 cells. There was no difference in total tubulin content between K562 and KPTA5 cells as analyzed by immunoblotting with an anti-beta-tubulin monoclonal antibody. However, we found that KPTA5 cells presented a 2-fold increase both in 5 beta-tubulin mRNA expression and in the corresponding tubulin protein Class IV isotype content, as evaluated by rt-PCR and immunostaining. In conclusion, the KPTA5 cell line displays a novel mechanism of resistance to paclitaxel which does not involve altered cellular drug accumulation. The data presented suggest that alterations in expression of the 5 beta-tubulin gene may be involved in paclitaxel resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Difference of allelotype between squamous cell carcinoma and adenocarcinoma of the lung.

We compared the frequency of loss of heterozygosity on all autosomal chromosomes among 41 squamous cell carcinomas and 119 adenocarcinomas, to analyze possible relationships of specific tumor suppressor gene(s) to each histological type. On the majority (28 of 36) of chromosomal arms tested, loss of heterozygosity was observed more frequently in squamous cell carcinomas than in adenocarcinomas; in nine of these locations (3p, 3q, 4q, 7p, 9q, 13q, 16q, 17p, and 21q), the frequency was statistically significant (3p, 3q, 4q, 9q, 13q, and 17p, P < 0.01; 7p, 16q, and 21q, P < 0.05, chi 2 test). In squamous cell carcinomas, the frequency of allelic loss on chromosome 9q (67%) fell between the frequencies of loss on chromosomes 3p (82%) or 17p (88%) and chromosome 13q (60%). On the other hand, in adenocarcinomas frequent loss of heterozygosity was observed on chromosomes 8q (32%), 9p (36%), 3p (40%), and 17p (51%). Furthermore, allelic losses on chromosomes 9p, 9q, and 13q tended to correlated with smoking. These results suggest that more genetic changes accumulate during tumorigenesis in squamous cell carcinomas than in adenocarcinomas and that unidentified tumor suppressor genes exist on chromosome 9q for squamous cell carcinoma and on chromosome 8q for adenocarcinoma of the lung. These differences may be related to differences in tumorigenic mechanisms, such as etiological factors, operating in the separate histologies.

Adenocarcinoma↗
PubMed1994

Somatic mutations of the MTS (multiple tumor suppressor) 1/CDK4l (cyclin-dependent kinase-4 inhibitor) gene in human primary non-small cell lung carcinomas.

Cytogenetic abnormalities of chromosome 9p21-22 have been documented in human non-small cell lung carcinomas (NSCLC). Recently, a candidate tumor suppressor gene, MTS1/CDK4l, was identified in this chromosomal region and frequent homozygous deletions of this gene were found in cancer cell lines derived from various types of tissues. We screened 64 primary NSCLCs, including 31 adenocarcinomas and 33 squamous cell carcinomas, for mutations in MTS1/CDK4l, and detected somatic mutations in 19 of the 64 tumors examined. Five were deletions and 14 were missense mutations. These results suggest that inactivation of MTS1/CDK4l plays an important role during carcinogenesis of NSCLC.

Adenocarcinoma↗
PubMed1994

High-performance liquid chromatographic determination of catecholamine metabolites and 5-hydroxyindoleacetic acid in human urine using a mixed-mode column and an eight-channel electrode electrochemical detector.

An HPLC system for the simultaneous determination of acidic catecholamine metabolites, related compounds and 5-hydroxyindoleacetic acid (5-HIAA) in human urine was developed. A mixed-mode (C18/anion-exchange) column with isocratic elution using citrate buffer and an eight-channel electrochemical detector were used. Vanilmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenyllactic acid (vanillactic acid, VLA), homovanillic acid (HVA), vanillic acid (VA) and 5-HIAA in urine were determined simultaneously. Detection limits and inter (n = 5) and intra-assay (n = 5) coefficients of variation were satisfactory. The mean of analytical recoveries (n = 3, +/- C.V. (%)) were between 97 +/- 3.2 (VMA) and 105 +/- 4.8 (VA). Correlations between the analytical results for VMA, HVA and 5-HIAA obtained by an established method and the present method were satisfactory. The mean +/- 2 S.D. of the excretion rates of VMA, DOPAC, VLA, HVA, 5-HIAA and VA in urine from healthy adult volunteers were 0.61-4.36, 0.13-1.02, 0-0.35, 0.67-6.55, 0.50-5.14 and 0-0.55 mg/g creatinine, respectively.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1994

"Hot spots" of chromium accumulation at bifurcations of chromate workers' bronchi.

To investigate the mechanisms underlying respiratory tract carcinogenesis in chromate workers, we measured the concentration of chromium in samples of tissues from 50 bronchial bifurcations and other bronchial tissue obtained at autopsy, or during surgical procedures, from 9 exchromate workers known to be at risk of developing lung cancer. The mean duration of exposure was 21 years and the average time between cessation of exposure and death/surgery was 15 years. The area of the tissue samples was measured by image analysis and the chromium concentration determined by neutron activation analysis. Chromium concentrations ranged from 0.04 to 39 x 10(-10) g/microns tissue thickness/mm2 and in 80% of the cases the concentrations were greater at bifurcations than in neighboring epithelial tissue. The mean concentration ratios between bifurcations and adjacent areas were 1.5 (n = 1) in the trachea, 3.0 (n = 9) in the main bronchi, 3.6 (n = 22) in lobar bronchi, and 10.9 (n = 3) in subsegmental bronchi. Our results demonstrated long-term retention of chromium in the bronchial walls of chromate workers and also that chromium concentrations were higher at airway bifurcations than elsewhere, thus providing solid evidence for a deposition "hot spot" concept.

Aged↗
PubMed1994

A 3-Mb physical map of the chromosome region 8p21.3-p22, including a 600-kb region commonly deleted in human hepatocellular carcinoma, colorectal cancer, and non-small cell lung cancer.

To isolate a putative tumor suppressor gene(s), we have constructed a physical map and a detailed deletion map of chromosome region 8p21.3-p22, where loss of heterozygosity (LOH) has been frequently seen in human hepatocellular carcinomas (HCC), colorectal cancers (CRC), and non-small cell lung cancers (NSCLC). The smallest commonly deleted region at 8p21.3-p22 in HCC and CRC was between the loci defined by C18-245 and C18-2644; in NSCLC, a region between C18-1051 and C18-2644 was commonly deleted. A contiguous physical map of 12 cosmid markers in the 8p21.3-p22 region was constructed by means of multi-color fluorescence in situ hybridization (FISH) and pulsed-field gel electrophoresis (PFGE). On the basis of this physical map, which spans roughly 3.1 Mb, the estimated sizes of the commonly deleted regions were at most 1.2 Mb in HCC and CRC and 0.6 Mb in NSCLC. As four of the 12 physically ordered markers are located within the 0.6 Mb region commonly deleted in all three tumor types, nearly one fourth to one fifth of the target region has already been covered with cosmid inserts.

Animals↗
PubMed1994

Characteristics of chromate workers' cancers, chromium lung deposition and precancerous bronchial lesions: an autopsy study.

The characteristics of lung cancers induced by inhaled chromate were studied in 13 consecutive autopsies on male ex-chromate workers. In addition to histopathology, we examined: (1) the relationship between the occurrence of lung cancer and the amount of chromium (Cr) deposited in the lung as determined by atomic absorptiometry and (2) the chronological changes in five precancerous lung lesions followed by bronchoscopy till death. Twenty-one cancers were identified, including 16 lung tumours observed either during follow-up or at autopsy. Of these 16 tumours, 13 were found in six subjects, implying a high frequency of multiple cancers. Eleven (69%) out of the 16 tumours were of squamous cell type (including carcinoma in situ), this being twice as frequent as in age-matched controls. A further characteristic was predominance in the central part of lung (69%). The lung Cr burden was very much higher [40-15,800 micrograms g-1 (dry)] in patients with lung tumours than in those without (8-28 micrograms g-1). Five of the precancerous lesions followed by bronchoscopy originated at bronchial bifurcations. Four of these cases showed a return to normal histology at autopsy even without therapy, and the other did not progress.

Aged↗
PubMed1994

Risk of lung cancer among cigarette smokers in relation to tumor location.

To evaluate the effect of cigarette smoking on lung cancer by tumor location and histological type, we compared the smoking history obtained from medical records of 605 patients with squamous cell carcinoma (194 males and 10 females) or adenocarcinoma (219 males and 182 females) of the lung and 183 patients with metastatic lung cancer (82 males and 101 females) who had been aged 40 years or over at the time of surgical resection at the Cancer Institute in Tokyo from 1973-1991. The tumors which developed in a main or segmental bronchus were classified as central type, and those in a subsegmental or more distal bronchi were categorized as peripheral type. Cases with adenocarcinoma were classified by a pathologist into two histological subtypes, papillary and tubular types, according to the WHO lung carcinoma classification. Risk of squamous cell carcinoma was strongly associated with cigarette smoking for both central (OR (odds ratio) = 10.3 in males and 4.4 in females) and peripheral sites (OR = 10.7 in males and 6.5 in females). There was no significant association between cigarette smoking and adenocarcinoma for any tumor site or histological subtype in both sexes.

Adenocarcinoma↗
PubMed1994

O6-methylguanine-DNA methyltransferase activity in the human lung persists with advancing age.

O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in the repair of DNA lesions induced by alkylating carcinogens in a wide range of animals. To determine the relationship between DNA repair activity and tumor susceptibility with advancing age the activity of MGMT was measured in normal lung tissue extracts from 66 patients with primary or metastatic lung cancer obtained at surgery. The age of the patients whose lung MGMT activity was measured ranged from 40 to 79 years (males) and from 40 to 80 years (females), and the values varied over 10-fold in both sexes (33 males and 33 females). Our results indicate that the MGMT enzyme protein is expressed at appreciable levels throughout life, and on age-associated rapid decline is not a feature in the human lung. Thus, any age-associated increase in lung cancer incidence cannot be ascribed to any change in MGMT activity. In order to assess other possible factors which might exert a modulating influence we examined the MGMT activity in relation to sex, tumor type and smoking. However, in none of these cases was any significant correlation evident.

Adenocarcinoma↗
PubMed1994

[Simultaneous determination of catecholamines, serotonin, and their precursors and metabolites in body fluid by an HPLC system with multi-electrode electrochemical detector].

We have developed two HPLC systems for the simultaneous determination of CA, 5-HT and their precursors and metabolites in human body fluid. One system consisted of two reversed-phase columns, a column switching device, a pair of electrodes for elimination of interferents and two sets of new electrochemical detectors with four electrodes. Using this system, adequate separation of peaks for 17 kinds of CA, 5-HT and their related metabolites in a standard solution required only 17 min. NE, MHPG, DOPAC, 5-HIAA, HVA and TRP levels in cerebrospinal fluid (CSF) were determined without any pretreatment of the CSF samples. The concentrations of DOPAC, 5-HIAA and HVA in CSF were significantly lower in Alzheimer's disease, vascular dementia and Parkinson's disease than in the controls. The other system was developed for determination of CA acidic metabolites and 5-HIAA in human urine. This system consisted of a mixed-mode column (C18/anion) and 8-channel electrochemical detector with isocratic elution of citrate buffer. Detection limits, precision and analytical recoveries of this method were satisfactory for clinical use.

Aged↗
PubMed1993

Identification and characterization of nuclear calmodulin-binding proteins of Saccharomyces cerevisiae.

Nuclear calmodulin-binding proteins of the yeast Saccharomyces cerevisiae were investigated. The soluble fractions after serial treatments of the isolated nuclei with buffers containing the nonionic detergent NP-40 (F1), 0.5 M KCl (F2) and 2.0 M KCl (F3) in this order, and the residual proteins (F4) were obtained. The calmodulin-binding proteins of the nucleus and nuclear subfractions were identified using the gel overlay method using 125I-calmodulin. Each subnuclear fraction contained a large number of components that bound calmodulin in a Ca(2+)-dependent or -independent manners. The calmodulin-binding proteins were isolated from F1 and F2 subnuclear fractions by affinity chromatography. The affinity-purified proteins bound calmodulin in a Ca(2+)-dependent manner when analyzed using the gel overlay method. The major calmodulin-binding components of F1 were 44, 42, 36, 32 and 29 kDa proteins, and those of F2 were 200, 100, 40, 42, 36, 34 and 32 kDa proteins. The isolated proteins also contained several Coomassie-blue stained proteins that did not bind calmodulin and, therefore, may represent the proteins associated with the calmodulin-binding proteins. Antisera raised against the affinity-purified preparation of F1 and F2 recognized almost all of the calmodulin-binding proteins present in the fraction and several other proteins of the nucleus. The presence of Ca(2+)-dependent protein phosphatase (type 2B) in the nucleus was demonstrated by Western blotting. The enzyme was localized predominantly in F1 and F4.

Calmodulin-Binding Proteins↗
PubMed1993

Cloning and characterization of the elongation factor EF-1 beta homologue of Saccharomyces cerevisiae. EF-1 beta is essential for growth.

A Saccharomyces cerevisiae cDNA homologue of the elongation factor EF-1 beta was found among the clones obtained by immunoscreening of a yeast cDNA expression library with an antibody against calmodulin affinity-purified proteins. The cDNA encoded a protein of 206 amino acids which was highly homologous (about 70% homology) with Artemia salina and human EF-1 beta. A protein with an apparent molecular mass of 33,000, significantly larger than that expected from the gene, was identified by Western blotting. Gene disruption experiments indicated that EF-1 beta is essential for growth.

Amino Acid Sequence↗