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Biomedical subjects

J Fujimoto

Publications and source records attributed to J Fujimoto.

At least 181 records · Page 10Linked to original sources
PubMed1997

Expression of estrogen receptor wild type and exon 5 splicing variant mRNAs in normal and endometriotic endometria during the menstrual cycle.

Expression of estrogen receptor exon 5 splicing variant (ER-E5SV) mRNA contributes to dominant positive properties and metastatic potential of gynecological cancers. Therefore, in endometriotic endometria, which conserve implantation and tumor-like spreading potentials, the expression of ER-E5SV and estrogen receptor wild type (ER-WT) mRNA was analyzed, to investigate the biological implications. Estrogen receptor wild type mRNA in normal endometria was downregulated after ovulation, but not in endometriotic endometria. Therefore the wild type cascade in endometriotic endometria might be partly disorganized. The level of ER-E5SV mRNA in endometriotic endometria was lower than that in normal endometria, regardless of the stage in the menstrual cycle. However, there was no significant difference in the ratio of ER-E5SV to ER-WT mRNA in both normal and endometriotic endometria. On the other hand, the level of ER-E5SV mRNA in both normal and endometriotic endometria did not vary during the menstrual cycle. The dominant positive behavior of ER-E5SV might be masked by the functional cascade of ER-WT in normal endometria, but not in endometriotic endometria. This status might result in an incomplete response to endogenous steroids, and contribute to implantation and spreading potentials of endometriosis.

Adult↗
PubMed1997

[Primary tubular impairment by verocytotoxin in hemolytic uremic syndrome].

Hemolytic uremic syndrome (HUS) in childhood is recognized as the most frequent cause of acute renal failure and is greatly associated with verotoxin-producing E. coli (VTEC) infection. Most of the prodromal feature in HUS associated with VTEC infection is hemorrhagic colitis (HC). HC progresses to HUS in several days. So it is important to detect whether the patient with bloody diarrhea is associated with VTEC infection or not. From 1992 to 1996 we analyzed clinical findings of 80 HUS and 29 HC patients. High level of beta 2-microglobulin (BMG) and N-acetyl-D-beta-glucosaminidase (NAG) in the urine were observed in the early stage of the disease. We went on to examine verotoxin (VT2)-binding in mouse (ICR) renal sections by enzyme immunoassay. Specific binding of VT2 to tubules was seen in mouse kidney, and intravenous injection of VT2 to mice caused acute tubular necrosis in 15 h whereas glomeruli were intact. These data suggest that the primary target cell of VT2 was tubules in the kidney of the HUS patients with VTEC infection.

Acetylglucosaminidase↗
PubMed1997

Expression of basic fibroblast growth factor and its mRNA in advanced ovarian cancers.

To investigate whether growth, invasion and metastasis of ovarian cancer cells is associated with neovascularization, the expression of basic fibroblast growth factor (FGF) and its mRNA in ovarian cancers and normal ovaries as controls were determined by ELISA and reverse transcription-polymerase chain reaction-Southern blot, respectively. The relationships between the expression and the histological grading, clinical backgrounds or clinical staging in ovarian cancers were analyzed. The levels of basic FGF and its mRNA were significantly higher in advanced primary ovarian cancers, regardless of histological types and some clinical backgrounds. Therefore, this status might contribute to the acceleration of growth, invasion, and metastasis with neovascularization in advanced ovarian cancers.

Adult↗
PubMed1997

Suppression of E-cadherin and alpha- and beta-catenin mRNA expression in the metastatic lesions of gynecological cancers.

To know the biological role of adherens junction, mainly consisting of E-cadherin and alpha- and beta-catenins, associated with invasion and metastasis of ovarian, uterine endometrial and cervical cancers, we studied the expression of E-cadherin and alpha- and beta-catenin mRNAs in the metastatic lesions in comparison with those in the primary tumors. The integral expression of E-cadherin and alpha- and beta-catenin mRNAs in the metastatic lesions in comparison with that of the primary tumors was suppressed in 4 of 5 cases of ovarian cancers, all cases of uterine endometrial cancers, and 4 of 5 cases of uterine cervical cancers. Therefore, the suppressed expression of the main adhesion molecules in the adherence junction might contribute to the cell-to-cell junctional dysfunction, which might lead to the acquisition of invasiveness and metastatic potential of gynecological cancers as one of the rate-limiting steps.

Aged↗
PubMed1997

Antiestrogenic compounds inhibit estrogen-induced expression of fibroblast growth factor family (FGF-1, 2, and 4) mRNA in well-differentiated endometrial cancer cells.

To clarify the effect of sex steroids on neovascularization in the growth, invasion and metastasis of endometrial cancer, the regulations of acid fibroblast growth factor (FGF-1), basic FGF (FGF-2) and hst-1 (FGF-4) mRNA expressions were studied in well-differentiated endometrial cancer cells under the influence of sex steroids. The levels of FGF-1 and 2 mRNAs in the well-differentiated endometrial cancer (Ishikawa) cells were significantly increased by estradiol. This increase was significantly inhibited by progestins (progesterone, medroxyprogesterone acetate [MPA] and 17 alpha-hydroxyprogesterone) and tamoxifen, but not by tetrahydrocortisol, hydrocortisone and danazol. The expression of FGF-4 mRNA was not altered by sex steroids. Therefore, estrogen might stimulate FGF-2 with FGF-1 secretion of endometrial cancer cells for neovascularization, and antiestrogenic compounds do inhibit estrogen-induced events.

Adenocarcinoma↗
PubMed1996

Characterization of the transforming activity of p80, a hyperphosphorylated protein in a Ki-1 lymphoma cell line with chromosomal translocation t(2;5).

We have molecularly cloned a cDNA encoding a protein uniquely expressed and hyperphosphorylated at tyrosine residues in a Ki-1 lymphoma cell that contained chromosomal translocation t(2;5). The encoded protein p80 was shown to be generated by fusion of a protein-tyrosine kinase and a nucleolar protein B23/nucleophosmin (NPM). The coding sequence of this cDNA turned out to be virtually identical to that of the fusion cDNA for NPM-anaplastic lymphoma kinase (ALK) previously cloned from the transcript of the gene at the breakpoint of the same translocation. Overexpression of p80 in NIH 3T3 cells induced neoplastic transformation, suggesting that the p80 kinase is aberrantly activated. The normal form of p80 was predicted to be a receptor-type tyrosine kinase on the basis of its sequence similarity to the insulin receptor family of kinases. However, an immunofluorescence study using COS cells revealed that p80 was localized to the cytoplasm. Thus, subcellular translocation and activation of the tyrosine kinase presumably by its structural alteration would cause the malignant transformation. We also showed that a mutant p80 lacking the NPM portion was unable to transform NIH 3T3 cells. Thus, the NPM sequence is essential for the transforming activity, suggesting that the chromosomal translocation is responsible for the oncogenesis. Finally, Shc and insulin receptor substrate 1 (IRS-1) were tyrosine-phosphorylated and bound to p80 in p80-transformed cells. However, mutants of p80 that were defective for binding to and phosphorylation of Shc and insulin receptor substrate 1 could transform NIH 3T3 cells. Association of these mutants with GRB2 was still observed, suggesting that interaction of p80 with GRB2 but not with Shc or IRS-1 was relevant for cell transformation.

3T3 Cells↗
PubMed1996

Synthesis and hydrolysis of oligodeoxyribonucleotides containing 2-aminopurine.

A new method is reported for the synthesis of oligodeoxyribonucleotides containing 2-aminopurine residues at selected sites. This method involves protection of the 2-aminopurine ribonucleoside, reduction to the deoxyribonucleoside and standard preparation of the 5'-0- (4,4'-dimethoxytrityl)-3'-O-(2-cyanoethyl)-N,N- diisopropylphosphoramidite. The 2-aminopurine phosphoramidite prepared by this method couples with high efficiency and is stable under standard automated synthesis conditions. The presence and location of the 2-aminopurine residue is easily verified by treatment of the oligodeoxyribonucleotide with hot piperidine. The mechanism for selective hydrolysis of the 2-aminopurine residue in alkaline solution is predominantly direct cleave of the glycosidic bond.

2-Aminopurine↗
PubMed1996

Inhibition of resistance to hemopoietic allo-grafts in granulocyte colony-stimulating factor transgenic mice.

Transplanted allogeneic marrow cells often fail to engraft in a lethally irradiated host. This phenomenon, termed resistance to allogeneic marrow grafts or alloresistance, is well documented, although its mechanism is not yet understood. Transplantation of major histocompatibility complex disparate allogeneic marrow cells into mice transgenic for granulocyte colony-stimulating factor (G-CSF) showed donor-derived spleen colonies (CFU-S) and resulted in stable allogeneic chimerism with excellent survival (100% up to 40 days and 89% up to 120 days). Under the same experimental conditions, all the littermate controls failed to show CFU-S and died shortly after marrow transplantation. Thus, resistance to allogeneic marrow cells appeared to be severely impaired in this transgenic mouse. The observation that neutralizing antibody against G-CSF restored allo-resistance in G-CSF transgenic mice and that CFU-S was inducible upon administration of recombinant G-CSF using a mini-osmotic pump in nontransgenic recipients, suggests that an elevated level of this cytokine is important for the inhibition of allo-resistance. Thus, G-CSF was found to play a role in allogeneic resistance to marrow grafts and the G-CSF-transgenic mice provide a useful model to study the inhibition of the resistance. The inhibition of allo-resistance may be useful in preparing allogeneic bone marrow chimeras in both experimental and clinical settings.

Animals↗
PubMed1996

Overexpression of granulocyte colony-stimulating factor in vivo decreases the level of polyploidization of mouse bone marrow megakaryocytes.

The in vivo effect of G-CSF on the maturation of mouse bone marrow megakaryocytes was studied by monitoring the DNA contents. Megakaryocytes were first identified by a specific 1C2 monoclonal antibody against mouse platelets and megakaryocytes and DNA contents of these cells were measured by propidium iodine. Megakaryocytes of mice transgenic for human G-CSF had a modal DNA class of 8N, showing a striking contrast to the previous reports that normal mouse megakaryocytes from most strains have 16N DNA content as a modal class. Daily 10 micrograms administration of G-CSF to mice for three to five days affected the DNA distribution pattern of bone marrow megakaryocytes, with a higher proportion of cells having 8N DNA contents. This G-CSF treatment, however, did not influence the peripheral blood platelet count or bone marrow megakaryocyte number. Administration of G-CSF along with thrombopoietin (TPO) reduced the proportion of megakaryocytes, with 32N DNA, the DNA class that was increased by TPO. Finally, the presence of mRNA for the mouse G-CSF receptor was demonstrated in two megakaryoblastic cell lines by reverse transcriptase polymerase chain reaction. These results indicated that G-CSF may have a suppressive effect on the maturation of mouse bone marrow megakaryocytes when monitored by the DNA polyploidy. Although further study is clearly necessary, the presence of mRNA for the G-CSF receptor in megakaryocytic lineage strongly suggests the direct action of G-CSF on this cell lineage.

Animals↗
PubMed1996

Expression of E-cadherin, alpha- and beta-catenin mRNAs in ovarian endometriosis.

To establish the mechanism of development of ovarian endometriosis from the biological function of the adherens junction, we have investigated the expression of E-cadherin, alpha- and beta-catenin mRNAs in ovarian endometriosis in comparison with that in normal uterine endometrium. The expression of E-cadherin, alpha- and beta-catenin mRNAs in ovarian endometriosis was not altered during the menstrual cycle. On the other hand, the expression in normal uterine endometrium significantly was increased at the secretory phase, and was significantly higher than that in ovarian endometriosis. In conclusion, the expression of E-cadherin, alpha- and beta-catenin mRNAs for adherens junction in ovarian endometriosis appeared to be decreased after ovulation, which might, at least in part, contribute to detachment as the first step of development of endometriotic cells.

Adolescent↗
PubMed1996

Progestins and danazol effect on cell-to-cell adhesion, and E-cadherin and alpha- and beta-catenin mRNA expressions.

The first step of invasion and metastasis is the detachment of cancer cells in the primary tumor, which is mainly controlled by the function in the adherens junction, consisting of E-cadherin associated proteins (E-cadherin, alpha- and beta-catenins, vinculin, alpha-actinin, and actin). The cell-to-cell aggregation activity and the expressions of E-cadherin, and alpha- and beta-catenin mRNAs in Ishikawa cells of well-differentiated endometrial cancer were significantly suppressed by estrogen. These suppressions were reversed by progesterone, medroxyprogesterone acetate (MPA) and danazol. Proteins in the adherens junction appeared to be expressed intact and to be functional in Ishikawa cells. Persistent estrogen predominant milieu might contribute to the detachment of well-differentiated endometrial cancer cells, leading to spreading of those cells, while progestins and danazol protect estrogen-induced spreading of those cells.

Adenocarcinoma↗
PubMed1996

Sex steroids regulate the expression of plasminogen activator inhibitor-1 (PAI-1) and its mRNA in uterine endometrial cancer cell line Ishikawa.

To know the effects of sex steroids on the potentials of growth, invasion, and metastasis with neovascularization of endometrial cancer, the expression of plasminogen activator inhibitor (PAI)-1 [an inhibitor of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA)] and its mRNA in well-differentiated uterine endometrial cancer cell line Ishikawa was determined by an enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction-Southern blotting (RT-PCR-SB), respectively, under the influence of sex steroids. In Ishikawa cells, either estradiol or progestins (progesterone, medroxyprogesterone acetate, or 17 alpha-hydroxyprogesterone alone) induced the expression of PAI-1 and its mRNA, and those expressions were increased approximately two-fold by both estradiol and progestin administered together. Therefore, sex steroidal induction of PAI-1 might contribute to the inhibition of invasion and metastasis, concomitantly with the inhibition of neovascularization associated with tPA and uPA activities, in well differentiated endometrial cancer.

17-alpha-Hydroxyprogesterone↗
PubMed1996

Selective inhibition of resistance to hemopoietic allografts but not rejection to a natural killer cell sensitive tumor in transgenic mice for granulocyte colony stimulating factor.

Transplanted allogeneic marrow grafts often fail to engraft in a lethally irradiated host. Resistance to hemopoietic allograft is a complexed phenomenon involving multiple components. To study the involvement of a hemopoietic cytokine, which was known to play a role for stem cell function, we established lines of mice that were transgenic for human granulocyte colony-stimulating factor (hG-CSF). Elevated and constitutive expression was found in sera (1,041 +/- 242 pg/ml) of these transgenic mice regardless of their sexes and ages. Strong neutrophilic granulocytosis correlated with the elevated G-CSF activity in transgenic mice but not in littermate controls, establishing a functional expression of this cytokine. In lethally irradiated mice transgenic for G-CSF, infusion of fully allogeneic marrow cells induced donor-derived spleen colony. Growth of hemopoietic allografts appeared to be similar to those of syngeneic marrow cells, which indicates inhibition of resistance for allogeneic marrow grafts. Because of a positive correlation, involvement of natural killer (NK) cells in resistance of transplanted allografts has been suggested. Inocula of NK-sensitive lymphoma cells were, however, vigorously rejected in the G-CSF-transgenic mice. This observation indicates that G-CSF may play a role in engraftment of transplanted allogeneic marrow grafts and may represent a component of mechanisms of hemopoietic resistance. Furthermore, this result may be an indication that alloresistance and NK cells use different mechanisms to resist each target.

Animals↗
PubMed1996

Estrogen activates migration potential of endometrial cancer cells through basement membrane.

The migration potential through a basement membrane in an endometrial cancer cell line, such as Ishikawa, HEC-1-A or HHUA cell, in terms of strength, was enhanced by estradiol, but not modified by progesterone, medroxyprogesterone acetate (MPA), danazol or tamoxifen alone, by which estradiol-enhanced migration potential was inhibited. The order of the level of estrogen receptor was Ishikawa > HEC-1-A > HHUA cells. Therefore, it is suggested that the invasiveness of endometrial cancer cells might be activated by estradiol via estrogen receptors, but inactivated by progesterone, MPA, danazol or tamoxifen as an antiestrogen action, and that endometrial cancer cells could become invasive in the estrogen-predominant milieu, and the antiestrogenic agents could protect it.

Antineoplastic Agents, Hormonal↗
PubMed1996

Expressions of the fibroblast growth factor family (FGF-1, -2 and -4) mRNA in endometrial cancers.

To investigate whether growth, invasion and metastasis of endometrial cancer cells is associated with neovascularization, the expressions of fibroblast growth factor-1 (acidic FGF), -2 (basic FGF) and -4 (hst-1) mRNAs and FGF-2 in endometrial cancers and normal endometria as controls were determined by reverse transcription-polymerase chain reaction-Southern blot and ELISA, respectively, and the relationships between their expressions and histological grades, grades of myometrial invasion or clinical stages of endometrial cancers were analyzed. The levels of FGF-1 mRNA and FGF-2 and its mRNA tended to increase with dedifferentiation (especially grade G3), myometrial invasion (especially grade C) and staging (especially stages III and IV) in endometrial cancers were significantly (p < 0.05) higher than those in normal endometria. However, the levels of FGF-4 mRNA expression were significantly (p < 0.05) lower than those of FGF-1 and -2 mRNAs in both endometrial cancers and normal endometria. Therefore, endometrial cancers might mainly secrete FGF-1 and -2, which leads to neovascularization to provide nutrition, resulting in accelerated growth, invasion and metastasis. Apparently, the increased secretion parallels the progressive malignancy of endometrial cancers.

Adult↗
PubMed1996

Sex steroids regulate the expression of plasminogen activator inhibitor-1 and its mRNA in fibroblasts derived from uterine endometrium.

In order to clarify a role of stromal cells in sex steroidal neovascularization, plasminogen activator inhibitor (PAI)-1 [an inhibitor of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA)] and its messenger ribonucleic acid (mRNA) were analysed in fibroblasts derived from uterine endometrium as a model for endometrial stromal cells under the influence of sex steroids. The determinations were carried out by an enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction-Southern blotting, respectively. In the fibroblasts, either estradiol or progestogens (progesterone, medroxy progesterone acetate or 17 alpha-hydroxyprogesterone) induced expressions of PAI-1 and its mRNA, and their combination further increased their expression by approximately twofold. PAI-1 from endometrial stromal cells under the influence of sex steroids might contribute to endometrial neovascularization through its effect on endothelial cells in endometrial vessels.

17-alpha-Hydroxyprogesterone↗