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B Sato

Publications and source records attributed to B Sato.

At least 91 records · Page 5Linked to original sources
PubMed1990

Roles of transforming growth factor beta in inhibition of androgen-induced growth of Shionogi carcinoma cells in serum-free medium.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. In a serum-free culture system we have established [Ham's F-12:Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], 10(-8) M testosterone markedly stimulates the growth of SC-3 cells (a cloned cell line from a SC115 tumor) via androgen receptor. The testosterone-induced growth of SC-3 cells, which has been shown to be mediated through autocrine fibroblast growth factor (FGF)-like peptide, was almost completely abolished by 1 ng/ml of transforming growth factor beta (TGF-beta). In the present study, mechanisms of the inhibitory effect of TGF-beta on the testosterone-induced growth of SC-3 cells were examined in the serum-free medium. Although the testosterone-induced growth was almost completely inhibited by TGF-beta, basic FGF- or FGF-like peptide (secreted from SC-3 cells by testosterone)-induced growth was only partially inhibited (45%) by TGF-beta. This difference can be explained by the fact that TGF-beta decreased the amount of testosterone-induced FGF-like peptide secreted from SC-3 cells to 18% of control. The TGF-beta-induced inhibition was found to be reversible. Furthermore, no significant effects of the TGF-beta treatment on number or affinity of both androgen and FGF receptors were demonstrated. The present findings show that TGF-beta markedly inhibits testosterone-induced secretion of FGF-like peptide from SC-3 cells and also inhibits growth-stimulatory effects of the secreted factor on SC-3 cells, probably via postreceptor mechanisms.

Animals↗
PubMed1990

Effect of retinoic acid on proliferation of estrogen-responsive transformed murine Leydig cells in serum-free culture.

B-1 F cells, one of the sublines established from mouse Leydig cell tumor, have been found to be maintained as an estrogen-responsive cell line under the serum-free culture conditions. Reported results that retinoids have action mechanisms similar to those of estrogen prompted us to examine the effect of retinoids on the proliferation of B-1 F cells. Stimulation of B-1 F cell growth by retinoic acid in a dose-dependent manner was observed, whereas retinoic acid did not promote but inhibited the proliferation of MCF-7 cells (estrogen- and retinoic acid receptor-positive human breast cancer cells). To elucidate the mechanism of retinoic acid-dependent cell growth, simultaneous treatment with retinoic acid and estradiol was carried out. The result did not show the additive effect on B-1 F cell growth. Hydroxytamoxifen, a potent antiestrogen, inhibited not only estradiol-dependent but also retinoic acid-dependent cell growth. However, retinoic acid failed to be associated with estrogen receptor, suggesting that retinoic acid induced enhancement of B-1 cell growth through its interaction with retinoic acid receptor. Northern blot analyses of polyadenylated RNA with complementary DNA probes for human retinoic acid receptor alpha, beta, and gamma revealed the presence of transcripts encoded by retinoic acid receptor alpha gene in B-1 F cells. These results would suggest that enhancement of the B-1 F cell growth is mediated through interaction of retinoic acid with retinoic acid receptor alpha. This stimulatory activity is inhibited by estrogen receptor complexed with hydroxytamoxifen.

Animals↗
PubMed1990

Effects of estrogen on cell proliferation and leukotriene formation in transformed mouse Leydig cells cultured under serum-free conditions.

B-1 F cells from mouse Leydig cell tumor (T 124958-R) were maintained in serum-free culture. Estrogen enhanced the growth of the cells, and this growth was suppressed by antiestrogens such as 4-hydroxytamoxifen or TAT, a newly developed antiestrogen. Since the growth of B-1 F cells was recently found to be inhibited by the metabolites of arachidonic acid, we examined the relationship between this metabolism and the enhancement of cell growth by estrogen. Among the modulators affecting the metabolism of arachidonic acid, 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoqu inone, an inhibitor of 5-lipoxygenase, reproducibly stimulated the growth of the cells, whereas the cyclooxygenase inhibitor indomethacin had only the marginal growth-stimulatory effects. Phorbol ester had no growth-modulating effect. 17 beta-Estradiol and 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoqu inone had some additive effects especially in terms of restoration of antiestrogen-induced inhibition. Moreover, the inhibition of DNA synthesis elicited by the addition of arachidonic acid in concentrations of 0.05 to 0.5 micrograms/ml was partly blocked by estrogen. Analyses of extracts of media and cells by high-pressure liquid chromatography and radioimmunoassay showed that 17 beta-estradiol inhibited the synthesis of leukotrienes B4, C4, D4, and E4 and this inhibition could be restored by antiestrogen. These results suggest that the enhancement of B-1 F cell growth by estrogen is at least partly mediated through its ability to inhibit leukotriene synthesis.

Animals↗
PubMed1990

Interaction of androgen-induced autocrine heparin-binding growth factor with fibroblast growth factor receptor on androgen-dependent Shionogi carcinoma 115 cells.

Stimulation of a Shionogi carcinoma 115-derived cultured cell line (SC-3) with androgen resulted in secretion of heparin-binding growth factor. In this study, we analyzed cell-surfaced receptors for growth factors. Binding data of growth factors on intact SC-3 cells revealed the presence of low and high affinity receptors for epidermal growth factor (EGF), insulin, and fibroblast growth factor (FGF). The dissociation constant values were 50 pM and 1.0 nM for EGF, 1.2 nM and 30 nM for insulin, and 34 pM and 7.5 nM for FGF. The numbers of maximal binding sites were 300 and 900/cell for EGF, 2,000 and 14,000/cell for insulin, and 13,000 and 810,000/cell for FGF. To examine the association of androgen-induced growth factor with one of these receptors, the conditioned medium prepared from androgen-stimulated SC-3 cells was fractionated through a heparin-Sepharose column. Growth factor activity adsorbed and eluted by 1 M NaCl from the column was comigrated with the activity inhibiting FGF-receptor association. In addition, basic 125I-FGF was cross-linked, using disuccinimidyl suberate, to the receptor with an apparent molecular weight of 130,000, whose labeling was inhibited when basic FGF, acidic FGF, or highly purified androgen-induced growth factor was present in excess. Furthermore, the highly purified growth factor-, basic FGF- or androgen-induced growth of SC-3 cells was significantly and similarly inhibited by anti-basic FGF antibody IgG. These results indicate that androgen-induced FGF-like factor acts as an autocrine growth factor via the FGF receptor in a process of SC-3 cell proliferation.

Animals↗
PubMed1990

Identification of unoccupied but transformed nuclear estrogen receptor in cultured mouse Leydig cell.

The molecular forms of estrogen receptor (ER) in estrogen-responsive mouse Leydig cell line (B-1) have been examined in relation to their biological activity. ER was predominantly recovered in the nuclear fraction upon homogenization even after cells were precultured in the absence of E2 and Phenol Red. This unoccupied nuclear ER (ERn) whose hormone binding ability was extremely thermostable could be extracted with 0.4 M KCl. This stability enabled us to determine hydrodynamic parameters in the ligand-free condition. The Stokes radius and sedimentation constant of this ERn in high salt condition were 5.5 nm and 6.0S, respectively, resulting in its molecular weight of 140,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of ER labeled with [3H]tamoxifen aziridine gave a single band of 65,000 Da, indicating that this ERn had a oligomer structure similar to that of transformed nuclear ER complexed with estrogen in the putative target cells. Therefore, we further examined the possibility that this ERn in B-1 cells can activate estrogen-responsive genes without any aid from estrogen. Estrogen responsive element-thymidine kinase promoter-chloramphenicol acetyltransferase fusion gene (ERE-tk-CAT) was transfected into B-1 cells. CAT activity was enhanced only in cells stimulated with estrogen. It may be concluded from these results that transformed ERn can be formed in the absence of estrogen but that binding to estrogen may be required in order to exert its biological activity.

Animals↗
PubMed1990

Growth stimulation by androgens, glucocorticoids or fibroblast growth factors and the blocking of the stimulated growth by antibody against basic fibroblast growth factor in protein-free culture of Shionogi carcinoma 115 cells.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. We have established an androgen-dependent cloned cell line (SC-3) from a SC115 tumor. In a serum-free medium, testosterone (T) or fibroblast growth factors (FGFs) markedly stimulate the growth of SC-3 cells, and the T-induced growth was shown to be mediated through FGF-like peptide(s) in an autocrine mechanism. Since we used the serum-free culture including 0.1% bovine serum albumin (BSA), a partially serum-containing condition, putative roles of BSA- or serum-borne growth factors in growth stimulation of autocrine production of FGF-like peptide(s) could not be excluded. This paper reports findings performed in a protein-free medium including plating [Ham's F-12:MEM (1:1; v/v)]. In the protein-free culture, the growth of SC-3 cells was significantly stimulated by the addition of greater than or equal to 10(-10) M T (up to 20-fold), greater than or equal to 10(-7) M dexamethasone (Dex; up to 7-fold) or greater than or equal to 1 ng/ml basic (b) or acidic FGF (up to 10-fold); other various growth factors had no such effects. Furthermore, DNA synthesis of SC-3 cells induced by T, Dex or bFGF was similarly and markedly inhibited by bFGF neutralizing antibody IgG. Therefore, the present findings seem to demonstrate that androgens or high levels of glucocorticoids induce the production and secretion of FGF-like peptide(s) from SC-3 cells for their growth even in the absence of additional support by other factors.

Androgens↗
PubMed1990

[Sipple's syndrome: a case report].

A 41-year-old woman was hospitalized for evaluation of diabetes mellitus and hypertension. The hormonal and radiological examinations revealed that she had pheochromocytoma of bilateral adrenal gland and medullary carcinoma of thyroid gland. Therefore, she was diagnosed as having Sipple's syndrome. She had no definite familial history, but her two sisters, already dead, had been strongly suspected of having had pheochromocytoma. First, bilateral adrenalectomy was performed and secondly, total thyroidectomy, excision of parathyroid and cervical lymph node dissection were performed. Histopathological diagnosis was pheochromocytoma of bilateral adrenal gland, medullary carcinoma of thyroid gland and chief cell hyperplasia of parathyroid gland. We report a case of Sipple's syndrome, which probably is the 88th case in Japan, with the review of the previous Japanese literature.

Adrenal Gland Neoplasms↗
PubMed1989

Inhibitory effect of antibody against basic fibroblast growth factor on androgen- or glucocorticoid-induced growth of Shionogi carcinoma 115 cells in serum-free culture.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. However, we and others recently found that the growth of SC115 cells is also stimulated by high doses of glucocorticoids. We already reported the following findings. In a serum-free medium [Ham's F-12: Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], greater than or equal to 10(-9) M testosterone and greater than or equal to 10(-8) M dexamethasone significantly stimulated the growth of SC-3 cells (a cloned cell line from a SC115 tumor) through androgen and glucocorticoid receptors, respectively. In the present study, we have demonstrated that higher concentrations (10(-7)-10(-6) M) of weak androgens such as 4-androstene-3,17-dione or weak glucocorticoids such as corticosterone also significantly stimulate the growth of SC-3 cells and that their relative potency is found to be in parallel with their binding affinity for their receptors, respectively. Furthermore, DNA synthesis of SC-3 cells induced by 0.1 ng/ml basic fibroblast growth factor (FGF), 10(-8) M testosterone, 10(-6) M 4-androstene-3,17-dione, 10(-7) M dexamethasone, or 10(-6) M corticosterone was found to be similarly and significantly inhibited by the addition of basic FGF neutralizing antibody IgG in the present study; approximately 70% inhibition of the basic FGF, androgen, or glucocorticoid effects was attained. We already reported findings which suggest that SC-3 cells produce FGF-like peptide for their testosterone-induced growth. Therefore, the present study presents new additive information to demonstrate that the growth-stimulatory activity of various androgens or possibly glucocorticoids on SC-3 cells is mediated through a FGF-like peptide in an autocrine mechanism.

Androstenedione↗
PubMed1989

Effect of androgen on proliferation of estrogen-responsive transformed mouse Leydig cells in serum-free culture.

We examined the effects of steroid hormones on the proliferation of transformed mouse Leydig cells (B-1) in serum-free culture condition. Among hormones examined, androgen as well as estrogen enhanced the cell proliferation rate. Hormone binding studies revealed that B-1 cells contained both androgen and estrogen receptors. In addition, androgen-enhanced cell growth was inhibited by antiandrogen, but not by antiestrogen, while estrogen-stimulated cell growth was suppressed by antiestrogen. However, the simultaneous addition of androgen and estrogen did not show an additive effect. Dose-response study on androgen-dependent cell growth revealed that relatively high concentrations (10(-7)-10(-6) M) of dihydrotestosterone were required to obtain the maximum response. This was at least partly explained by the finding that B-1 cells could metabolize dihydrotestosterone into the less active steroids. Finally, B-1 cells were found to grow more rapidly in normal than in castrated male mice. These results clearly indicate that the proliferation of B-1 cells is stimulated by both androgen and estrogen, which utilize the different receptor systems.

Androgens↗
PubMed1989

Growth-stimulatory effects of androgen, high concentration of glucocorticoid or fibroblast growth factors on a cloned cell line from Shionogi carcinoma 115 cells in a serum-free medium.

The effects of various kinds of growth factors or steroids on the proliferation of Shionogi carcinoma 115 (SC115) cells were investigated in cell culture. In a serum-free medium [Ham's F-12:Eagle's minimum essential medium (1:1, vol/vol) containing 0.1% bovine serum albumin], the proliferation of SC-3 cells (a cloned cell line from SC115 cells) estimated by [3H]thymidine incorporation into DNA and cell number reached a plateau at 10(-8) M testosterone (up to 200-fold), 10(-7) M dexamethasone (up to 30-fold) or 1 ng/ml of fibroblast growth factors (FGF; up to 50-fold). However, the proliferation in the serum-free medium was not significantly stimulated by the addition of low to very high concentrations of progesterone, oestradiol-17 beta, epidermal growth factor, platelet derived growth factor or insulin; transforming growth factor beta slightly stimulated the growth (up to 5-fold) but markedly inhibited the growth stimulation induced by testosterone. Furthermore, an epithelial appearance of SC-3 cells grown in the absence of growth factors or steroids was changed to a fibroblast-like appearance only by the addition of testosterone, high concentrations of dexamethasone or FGF. By investigating various kinds of growth factors or steroids, the present study demonstrates that androgen, high concentration of glucocorticoid or FGF alone significantly stimulates the proliferation of SC-3 cells with a change of morphology in the serum-free medium.

Animals↗
PubMed1989

Growth control of androgen-dependent Shionogi carcinoma cells by growth factor(s) produced from androgen-independent Shionogi carcinoma cells in a paracrine mechanism.

Androgen-dependent (SC3) and -independent (CADO21) cloned cell lines were established from androgen-dependent mouse mammary tumor (Shionogi carcinoma 115). The effects of conditioned medium (CM) collected from SC3 and CADO21 cells on the anchorage-independent growth of SC3 cells in soft agar were studied. CM prepared from SC3 cells in the absence of testosterone was unable to stimulate the growth of SC3 cells, whereas CM prepared from SC3 cells in the presence of 10(-8) M testosterone stimulated the growth of SC3 cells in a concentration-dependent manner (21 colonies at 10% and 48 colonies at 20%) and this growth-stimulatory effect was not inhibited by 10(-6) M cyproterone acetate. CM prepared from CADO21 cells in the absence of testosterone was also able to stimulate the SC3 cell growth in a concentration-dependent manner (9 colonies at 10% and 19 colonies at 20%). These results suggest that the growth of androgen-dependent SC3 cells is stimulated by androgen-induced growth factor(s) produced from the same cells (autocrine mechanism) and is also regulated by autonomous growth factor(s) produced from androgen-independent cancer cells formed from the dependent cancer cells (paracrine mechanism). A suggested possible mechanism of the progression from androgen-dependent to -independent growth of cancer cells is also discussed.

Androgens↗
PubMed1989

Enzyme-immunoassay for estrogen receptors in human pituitary adenomas.

We have performed an enzyme-immunoassay for estrogen receptor on 56 human pituitary adenomas and compared the results with a single point estradiol binding assay. There was a significant positive correlation between the two assays of cytoplasmic estrogen receptor (r = 0.960). Normal human pituitaries (N = 2) had an estrogen receptor concentration of 17 fmol/mg protein by enzyme-immunoassay. Of 14 prolactinomas, 6 (43%) contained estrogen receptor with a concentration of 33.5 +/- 7.4 (mean +/- SEM) fmol/mg protein. Six of 11 (55%) macroprolactinomas were estrogen receptor-positive, whereas all 3 microprolactinomas were estrogen receptor-negative. Only one (13%) of 8 GH- and PRL-secreting adenomas, and 3 of 6 (50%) gonadotropin-secreting adenomas were estrogen receptor-positive; the latter had a concentration of 13.5 +/- 1.6 fmol/mg protein. Estrogen receptor was not detected in 21 pure GH-secreting adenomas and 7 nonsecreting adenomas. These results demonstrate the precise frequency of estrogen receptor in various human pituitary adenomas, since enzyme-immunoassay as well as single point estradiol binding assay could detect estrogen receptor even in small specimens. Enzyme-immunoassay is suitable for evaluation of estrogen receptor status in human pituitary adenomas.

Adenoma↗
PubMed1989

[Steroid hormone responsive cells in serum-free culture--analyses of hormone-mediated gene expression and cell growth].

Steroid hormone-responsive cell lines were clones from mouse mammary cancer (Shionogi Carcinoma 115) and Leydig cell tumor. SC-3 and SC-4 cells from Shionogi Carcinoma were androgen-responsive and -unresponsive in a serum-free medium, respectively. SC-3 cells secreted FGF-like growth factor as well as 24 K glycoprotein in response to androgen stimuli. B-1 and B-1F cells from mouse Leydig cell tumor were growth-stimulated in a serum-free medium by estrogen, androgen or retinoic acid. Transfection of ERE-TK-CAT gene into B-1F cells revealed that both estrogen and retinoic acid activated the CAT activity. In addition, the presence of corresponding receptors for steroid hormones or retinoic acid was demonstrated by hormone binding assays and/or Northern blot analysis. Thus, these serum-free culture systems seem to be very useful for analysing hormone action mechanisms in vitro.

Androgens↗
PubMed1989

[Effects of combined instillation of dapiprazole and epinephrine on human anterior chamber depth, intraocular pressure and pupil diameter].

Pilocarpine, a first choice drug for primary angle closure glaucoma (PACG), is reported to produce shallow anterior chamber and posterior synechia and consequently a small immobile pupil. In this paper, dapiprazole, a newly synthesized alpha 1 blocker, was given topically in combination with epinephrine eye drops to 15 healthy volunteers and 10 patients with PACG. In both volunteers and patients, the treated eyes revealed deeper anterior chambers, thinner lenses and significant IOP reduction after the combined instillation of dapiprazole and epinephrine. Though light reaction was preserved, mild miosis was observed in volunteers, but no pupillary change in patients. The conjunctival hyperemia induced by dapiprazole was reversed by additional instillation of epinephrine. Burning sensation was the only side effect observed after instillation of dapiprazole. In conclusion, the combined instillation of dapiprazole and epinephrine appears to be a good choice for the therapy of PACG.

Adrenergic alpha-Antagonists↗
PubMed1988

Growth-stimulatory effect of androgen-induced autocrine growth factor(s) secreted from Shionogi carcinoma 115 cells on androgen-unresponsive cancer cells in a paracrine mechanism.

Androgen-responsive (SC-3) and -unresponsive (SC-4) cloned cell lines in culture were established from an androgen-responsive mouse mammary tumor, Shionogi carcinoma 115. By using a serum-free medium [Ham's F-12:Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], characteristics of androgen-induced and autonomous growth factors (GFs) were examined. Serum-free conditioned medium (CM) obtained from testosterone-stimulated (+T) SC-3 cells had remarkable growth-stimulatory effects on both SC-3 and SC-4 cells. To examine the molecular characteristics of GF, CM(+T) from SC-3 was fractioned by heparin-Sepharose affinity chromatography; two peaks, eluted at 0.5 M (GF-low) and 1.1 M NaCl (GF-high) were identified. GF-high had the ability to stimulate growth with a morphological change of both SC-3 and SC-4 cells; the GF-high was not found in CM from T-unstimulated (-T) SC-3 or CM from SC-4. GF-low stimulated the growth without the morphological change of only SC-4 cells; the GF-low was also present in CM(-T) from SC-3 and CM from SC-4. The present findings demonstrate that T-induced autocrine GF-high secreted from SC-3 cells can also stimulate the growth of progressed unresponsive SC-4 cells in a paracrine mechanism and that autonomous GF-low secreted from both SC-3 and SC-4 cells can stimulate the growth of only SC-4 cells.

Androgens↗
PubMed1988

Autocrine regulation of cell proliferation by estradiol and hydroxytamoxifen of transformed mouse Leydig cells in serum-free culture.

We have previously reported that the cloned cell line (B-1-A-2) derived from an estrogen-responsive mouse Leydig cell tumor shows an estrogen-dependent enhancement of cell proliferation in medium supplemented with charcoal-dextran-stripped fetal bovine serum. To avoid the involvement of unknown factors present in the serum in the pathway for estrogen-dependent cell growth, the present study was designed to establish a serum-free culture system to which growth factors could be added. To this end, we subcloned B-1 cells from the parental tumor cell line. The proliferation of B-1 cells was markedly stimulated by the addition of 10(-11)-10(-8) M estradiol into the serum-free medium [Eagle's Minimum Essential Medium-Ham's F-12 (1:1, vol/vol) containing 0.2% (wt/vol) BSA]. Epidermal growth factor (0.1-50 ng/ml) or insulin (0.1-50 micrograms/ml) alone or in combination with 10(-8) M estradiol did not affect the proliferation rate of B-1 cells. In contrast, a greater than 10-fold molar excess of 4-hydroxytamoxifen blocked estradiol-induced cell proliferation, while 4-hydroxytamoxifen alone failed to show a stimulatory effect on cell multiplication. Additionally, the conditioned medium collected from estradiol-stimulated cells was found to contain a growth-promoting factor(s) whose activity was not antagonized by 4-hydroxytamoxifen. Nonstimulated cells secreted a significant but low level of the growth-promoting factor. Finally, B-1 cells were found to be estrogen dependent for cell proliferation in BALB/c mice. Their growth was markedly inhibited by the administration of tamoxifen to the host mice. These results indicate that the serum-free culture system presented here is suitable for studying the autocrine mechanisms of cell growth regulated by estrogens as well as triphenylethylene compounds.

Animals↗