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T Sasahira

Publications and source records attributed to T Sasahira.

12 recordsLinked to original sources
PubMed2006

Determinants for prediction of malignant potential by metalloproteinase:E-cadherin ratio in prostate core needle biopsy.

According to a good correlation between in situ hybridization-based metalloproteinase-2/9:E-cadherin ratio (MER) and the pathological stage of prostate cancer, we set the cutoff line of MER at 6.0 (MER>6) to distinguish between organ-confined (pT2) and advanced diseases (pT3a-b/N1). In this study, we looked at the factors affecting MER and leading to a misprediction of the pathological stage. We examined MER in 39 paired specimens of prostate core needle biopsy and prostatectomy from the same patient and compared these MERs. In 34 (87%) of 39 cases, the MER of biopsy was correlated with the final pathological stage (pT2 vs. pT3a-b/N1). MER ranges in pT3a-b/N1 cancer were significantly wider than those in pT2 cancer (p < 0.01). The number of MER>6 fields in Gleason score 8-9 cancer was larger than that in Gleason score 7 cancer (p < 0.0001). In 5 cases where there was a failure to distinguish pT2 from pT3a-b/N1, the misdiagnosis was significantly associated with a small number of biopsies (4 or 6 specimens; p = 0.0469), a small amount of tumor tissue in biopsy specimens (less than 5 mm; p = 0.0492), and a wide MER range (more than 5.0; high intratumoral heterogeneity; p = 0.0202). Considering these factors increases the usefulness of preoperative prediction of the final pathological stage by MER in prostate cancer.

Biomarkers, Tumor↗
PubMed2005

Interleukin-15 and transforming growth factor alpha are associated with depletion of tumor-associated macrophages in colon cancer.

We examined the effects of IL-15 and TGF-alpha on the inhibition of macrophage infiltration into colon cancer tissue, and secretion of amphoterin from colon cancer cells. Production of IL-15 and/or TGF-alpha was associated with depletion of tumor-associated macrophages (TAMs) in both Dukes' B and C tumors (P = 0.0324 and 0.0051, respectively). Production of IL-15 and/or TGF-alpha was also associated with amphoterin mRNA expression in colon cancer tissues with TAM depletion in both Dukes' B and C tumors (P = 0.0167 and P = 0.0062, respectively). WiDr human colon cancer cells treated with IL-15 and/or TGF-alpha induced reduction of nucleus-localized amphoterin and an increase in cytosolic and membranous amphoterin. Moreover, IL-15 and/or TGF-alpha treatment increased amphoterin secretion by WiDr cells. Most notably, IL-15 and TGF-alpha treatment induced the increase of cytosol/membrane localization and secretion of amphoterin and the most pronounced effect among the treatments carried out. These results suggested that IL-15/TGF-alpha promotes depletion of TAMs and secretion of amphoterin in colon cancer.

Antigens, CD↗
PubMed2005

High concentration of deoxycholic acid abrogates in vitro transformation of IEC6 intestinal cells by azoxymethane.

In this study, we designed an in vitro azoxymethane (AOM)-induced carcinogenesis model and analyzed the effect of deoxycholic acid (DCA) on growth, apoptosis, genotoxicity, and transformation of IEC6 intestinal cells. CYP2E1 production was confirmed in IEC6 cells. The growth of IEC6 cells was enhanced by DCA (100 microg/ml). However, IEC6 cells treated with DCA (200 microg/ml) were inhibited and disappeared at 48 hrs after treatment. Apoptotic cells increased 11.2 times by treatment with DCA (200 microg/ml) as compared to cells with no treatment. DNA injury detected by comet assay was found in cells treated with AOM, but not in cells treated with DCA (100 microg/ml) and AOM. The number of colony formation in soft agar increased by AOM treatment. However, the number of foci treated with DCA (100 microg/ml) plus AOM was 69% that of cells treated with AOM alone. Two out of the 6 mice subcutaneously injected with AOM-treated IEC6 cells showed tumorigenesis, whereas IEC6 cells treated with DCA (100 microg/ml) plus AOM or DCA (100 microg/ml) alone did not form any tumor. Reduced protein expression of MLH1, Bcl-2 was detected in IEC6 cells treated with DCA (100 microg/ml). Production of Bax, pJNK, TGF-beta, TGFBRI, TGFBRII, and beta-catenin were higher in IEC6 cells treated with DCA (100 microg/ml) than that in cells with no treatment. These results suggest that high-dose DCA induced apoptosis and inhibited AOM-induced in vitro transformation of IEC6 cells.

Animals↗
PubMed2004

Repression of MLH1 and MGMT genes in colon mucosa adjacent to implanted cancer in athymic mouse.

Hyperplastic mucosa adjacent to colon cancer, being a reactive change, accelerates cancer progression and its metastasis through expression of angiogenic factors. We investigated promoter methylation in hyperplastic mucosa adjacent to orthotopic KM12SM colon cancer in mice. In the hyperplastic mucosa adjacent to KM12SM tumors in the cecum of athymic mice, reductions in the levels of the mutL homologue 1 (MLH1) and O6-methylguanine-DNA methyltransferase (MGMT) proteins were detected by immunohistochemistry and immunoblotting. To examine the effects of growth factors and cytokines on promoter methylation and repressed expression of the MLH1 and MGMT genes, a rat intestinal epithelial cell line, IEC6, was treated with epidermal growth factor (EGF) and interleukin (IL)-15 for 35 days. Protein levels of MLH1 and MGMT were reduced in EGF- and IL-15-treated IEC6 cells. A methylation-sensitive restriction enzyme assay revealed that CpG methylation was present in the promoter regions of the MLH1 and MGMT genes in DNAs extracted from hyperplastic mucosa adjacent to KM12SM tumors. These findings suggest that promoter CpG methylation affects expression of MLH1 MGMT genes in hyperplastic mucosa adjacent to colon cancer.

Adaptor Proteins, Signal Transducing↗
PubMed1993

[An oxidation enzyme for hydrogen sulfide from Hyphomicrobium neptunium ATCC15444].

We described in our previous paper that the cell-free extract from Hyphomicrobium neptunium ATCC 15444 oxidized hydrogen sulfide to sulfur. We tried to purify the enzyme used for this oxidation to determine the molecular nature of this enzyme. The 40% ammonium sulfate precipitate from the supernatant of cell sonicate of H. neptunium was chromatographed on a column of Phenyl Sepharose CL-4B and its active fractions were collected. These fractions were further purified through Superose 12 and then TSK gel G3000SW column chromatographies. A protein of molecular weight about 54,000 and isoelectric point pI 6.8 was isolated. However, this final protein was found to reduce its activity to less than one-tenth of those of ammonium sulfate precipitate and of the fraction from Phenyl Sepharose CL-4B column chromatography. This might be caused either by the loss of accessory component or by its requirement of low molecular factors necessary for its activation at the stage of gel filtration. The neutral isoelectric point of this enzyme could be suitable as the function of H. neptunium because its final product was S0, and it grows at neutral pH. In contrast, the final oxidative product of hydrogen sulfide by Thiobascillus is sulfuric acid, and they grow at acidic pH.

Bacteria↗
PubMed1992

[Oxidation of hydrogen sulfide with cell-free extract of Hyphomicrobium neptunium ATCC 15444].

Soluble (Fr. 1) and membrane (Fr. 2) fractions were prepared from the cell-free extract of Hyphomicrobium neptunium ATCC 15444, and their effects on the oxidization of hydrogen sulfide (H2S) were studied. When H2S gas was supplied to Fr. 1 and Fr. 2, sulfur in both fractions and the majority of thiosulfate ion in Fr. 1 were detected. The sulfide-oxidizing activity in Fr. 2 but not in Fr. 1 was inhibited by the addition of diethyldithiocarbamate, suggesting that Fr. 1 and Fr. 2 have different types of sulfide-oxidase, and that Fr. 2 would include cytochrome c dependent sulfide oxidase. It was also found that thiosulfate ion was formed from sulfur and sulfite ion by adding Fr. 1. However, the pronase-treatment of Fr. 1 did not influence on the formation of thiosulfate ion. These results suggest that H2S was oxidized to sulfur and sulfite ion by two types of sulfide oxidase and sulfur oxidase in H. neptunium ATCC 15444, and that the sulfite ion changed rapidly to thiosulfate through a non-enzymatic reaction with sulfur.

Bacteria↗
PubMed1980

Taxonomy of the antibiotic Bu-2313-producing organism. Microtetraspora caesia sp. nov.

An aerobic actinomycete strain isolated from an Indian soil sample and designated No. E864-61 was found to produce in submerged fermentation a new antibiotic complex, Bu-2313 (components A and B). Strain E864-61 forms single, pairs or chains of three to eight spores on the aerial mycelium and its aerial mass color is grayish blue-green. The cell wall of strain E864-61 contains meso-diaminopimelic acid and galactose. Strain E864-61 has been classified as a new species of the genus Microtetraspora and designated as Microtetraspora caesia sp. nov.

Aminoglycosides↗
PubMed1978

Streptoalloteichus, a new genus of the family Actinoplanaceae.

A new genus Streptoalloteichus is proposed in the family Actinoplanaceae to distinguish species of actinomycetes which form short or long spore-chains on aerial mycelium, bears oval sporangia with motile spores and has a characteristic cell-wall composition of strain C677-91 type. Strain C677-91 (ATCC 31217, FERM-P No. 4070) was named Streptoalloteichus hindustanus gen. nov. and sp. nov. The actinomycete strain C677-91 produces spore-chain clusters and sclerotia in the aerial mycelium which are morphologically similar to those found in some species of Streptomyces. The cultural characteristics of the strain on agar media also resemble those of Streptomyces species and the colonies have no distinct color. Strain C677-91 produces sporangia or sporangia-like vesicles which contain one to several spores in the vegetative mycelium. The sporangiospores possess a single long polar flagellum and are motile. The cell wall of strain C677-91 contains meso-alpha,epsilon-diaminopimelic acid, alanine, glutamic acid, galactose, mannose, rhamnose and glucosamine. Strain C677-91 has several important characteristics in common with Streptomyces tenebrarius including the production of nebramycin factors but the latter strain does not produce sporangia.

Actinomycetales↗