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S Shirotake

Publications and source records attributed to S Shirotake.

33 records · Page 2Linked to original sources
PubMed1984

Effect of cytochalasin B on growth, Multinucleation and human chorionic gonadotropin secretion in a human choriocarcinoma cell line.

Treatment of human choriocarcinoma cells with cytochalasin B at the doses of inhibiting cell division but not inhibiting nuclear division led to in vitro formation of the multinucleated syncytiotrophoblast-like ( STL ) cells. A concomitant increase in human chorionic gonadotropin (hCG) secretion per cell was noted. Immunocytochemical staining demonstrated the predominant localization of hCG in the STL cells. These results indicate that multinucleation stimulates hCG synthesis and secretion in the choriocarcinoma cells.

Cell Division↗
PubMed1984

[Effects of various agents on the proliferation and hCG secretion of choriocarcinoma cells in vitro].

Effects of sex steroids, LH-RH, cyclic AMP and differentiation promoters on the proliferation and hCG secretion of two choriocarcinoma cell lines (BeWo and HCCM-5) were examined in vitro. The results were as follows. 1) Physiological concentrations of estradiol or progesterone revealed no effect on proliferation or hCG secretion, but pharmacological ones (more than 10 micrograms/ml) inhibited both the cell proliferation and its hCG secretion. 2) LH-RH and cyclic AMP slightly inhibited the proliferation of cells, and hCG secretion per cell was concomitantly enhanced. Cyclic AMP enhanced hCG secretion more markedly than LH-RH. 3) Retinoic acid had no effect on either cell proliferation or hCG secretion, whereas sodium butyrate inhibited both cell proliferation and hCG secretion. These results suggest that modifiers of hCG secretion may be grouped as follows; agents that inhibited cell proliferation slightly and enhanced hCG secretion markedly (LH-RH, cyclic AMP), agents that inhibited cell proliferation markedly and enhanced hCG secretion slightly (anticancer drugs) and agents that inhibited both cell proliferation and hCG secretion (estradiol, progesterone and sodium butyrate).

Cell Division↗
PubMed1984

[Study on the new development of highly sensitive E2-EIA used by two specific binding systems and on the clinical application].

As a tracer, biotin was bound to the amino group of newly synthesized 6-ethylenediamino-17-beta-estradiol. Two competitive methods were developed by using the tracer (E2-B). Method I, E2-B, sample, and anti E2 antibody conjugated with horse radish peroxidase were mixed, and the mixture was added to the avidin immobilized on a microplate to separate free and bound tracer. Then the enzyme activity which remained after washing was measured by using H2O2 and o-phenylenediamine. E2 was quantified from 75 pg/ml to 9.6 ng/ml; (II) E2-B and the samples were added to the anti E2 adsorbed on a microplate. After washing, the avidin conjugated with HRP was put into the immune complex plate, and the enzyme activity which remained was determined to calculate E2. The standard curve indicated E2 from 75 pg/ml to 19.2 ng/ml. The E2 values obtained by the new methods correlated with those by 3H-RIA and the EIA was useful in monitoring the induction of ovulation.

Adult↗
PubMed1984

[Isolation and properties of methotrexate-resistant choriocarcinoma cells in vitro].

The sensitivity to methotrexate (MTX) of ten kinds of human choriocarcinoma cell lines was studied in vitro. The cell line most sensitive to MTX was HCCM-5 and it was fed with a medium containing increasing concentrations of MTX. A resistant subline (HCCM-5R) which could proliferate in the medium containing 5 X 10(-7)M MTX was obtained after about 80 weeks of feeding. The properties of HCCM-5R cells were compared with those of the parent HCCM-5 cells. i) There were no apparent differences in morphology between the HCCM-5 and HCCM-5R lines. The population doubling time was almost the same for both cell lines. ii) The hCG level in the culture fluid of the HCCM-5R cells was about twice as high as that of the HCCM-5 cells. iii) The concentration of MTX which inhibited 50% of DNA synthesis in HCCM-5R cells was 10,000 times higher than that for HCCM-5 cells. iv) Each X and Y chromosome was identified in 90% of the HCCM-5 cells, while no Y chromosome was detected in the HCCM-5R cells. v) The DNA distribution pattern for HCCM-5R cells consisted of a large fraction of each cell with DNA G1 phase content and distributed in the tetraploid range, whereas that of HCCM-5 showed no particular cell cycle pattern. vi) The incorporation of 3H-MTX in the HCCM-5R cells was one tenth of that in the HCCM-5. vii) The intracellular DHFR activity of the HCCM-5R cells was about 5 times higher than that of HCCM-5. These results suggest that MTX-resistant cells among the HCCM-5 cells were selected in long-term contact with MTX, and sensitivity to MTX was concerned with both the MTX transport and intracellular DHFR levels.

Cell Division↗
PubMed1983

Effect of methotrexate on the growth and human chorionic gonadotropin secretion of human choriocarcinoma cell lines in vitro.

The effect of methotrexate (MTX) on the growth and human chorionic gonadotropin (hCG) secretion of five gestational and two nongestational human choriocarcinoma cell lines was studied in vitro. A striking heterogeneity in hCG secretion was noted among the cell lines. The growth of cells which secreted large quantities of hCG, such as HCCM-5, BeWo, and IMa, was inhibited by continuous exposure to 2 X 10(-8)M MTX. In contrast, cells which secreted little hCG, such as SCH, ENAMI-1, and GCH-1, showed no response to the growth inhibitory action of 2 X 10(-8)M MTX and the 3H-thymidine uptake was not reduced by treatment with MTX at doses of up to 10(-4)M for 48 hours. The common morphologic alterations observed in the cells which responded to MTX were an increase in the number of multinucleated giant cells, the appearance of vacuoles and granules in the cytoplasm, and enlargement of the nuclei. Increased hCG secretion was observed in accordance with the appearance of such morphologically altered cells. Part of the mechanisms of resistance to MTX appeared to involve both impairment of MTX uptake by the cells and an increase in the level of intracellular dihydrofolate reductase.

Cell Line↗
PubMed1983

Establishment and properties of a human choriocarcinoma cell line of ovarian origin.

A human nongestational choriocarcinoma cell line of ovarian origin (IMa) was established in vitro. This cell line had been subcultured serially more than 22 times over 18 months. Small polygonal cells with a prominent nucleus were dominant and a sparsity of cytoplasmic organelles was an ultrastructural characteristic of the IMa cells. The production and secretion of human chorionic gonadotropin and its subunits were identified by radioimmunoassay. The IMa cells were transplantable in the hamster cheek pouch and the histological diagnosis was choriocarcinoma. A newly established ovarian choriocarcinoma cell line can be considered useful for clarifying the biological differences between nongestational and gestational choriocarcinoma cells.

Animals↗
PubMed1983

A newly established human gestational choriocarcinoma cell line and its characterization.

The cell biological characteristics of a newly established human gestational choriocarcinoma cell line, HM, were examined and compared with four other gestational and two nongestational choriocarcinoma cell lines. Striking heterogeneity in the production and secretion of hCG and its subunits was observed among the cell lines. The HM cell line consisted mainly of cytotrophoblast-like cells, and the hCG and its subunit values in both the cells and culture fluid were extremely low. The syncytiotrophoblast-like multinucleated giant cells which were occasionally seen in other cell lines were scarce in the HM cell line in vitro. On the other hand, deviation of the LDH isozyme pattern to the heart-type (LDH1) was characteristic of the HM cells in contrast to the other cell lines in which LDH3 was dominant. The HM cell line represents useful material for investigating the cell biological heterogeneity of human choriocarcinomas.

Adult↗
PubMed1983

Characterization of human choriocarcinoma cell lines secreting high and low amounts of chorionic gonadotropin.

The secretory potential of human chorionic gonadotropin (hCG) in eight strains of human choriocarcinoma cell lines was examined in vitro and the correlation between the secretory potential and certain cell biological characteristics was studied. Multinucleated giant cells (syncytiotrophoblast-like cells) were occasionally observed only in high hCG-secreting cell lines in accordance with inhibition of growth. Appearance of abundant dilated rough endoplasmic reticulum and aggregated glycogen particles in the cytoplasm seemed to represent ultrastructural characteristics of high hCG-secreting cell lines. A shift of nuclear DNA to hyperploidy, its wide distribution, and S phase accumulation of cells by flow cytometry were also characteristic of them. However, no correlation was noted between the hCG secretory potential and population doubling time of the cell lines in vitro.

Cell Line↗
PubMed1983

[Studies on enzymeimmunoassay for human chorionic gonadotropin and its clinical application].

Two enzyme immunoassays for hCG were developed and compared with HAR and RIA by using many urine and serum samples. The EIA was characterized by management of trophoblastic disease. 1. An EIA by hCG-beta antibody immobilized on a microplate and hCG antibody conjugated with HRP enzyme quantified hCG from 0.5 to 100ng/ml, while the other by biotinyl hCG antibody and avidine-HRP conjugate quantified hCG from 0.1 to 20ng/ml. Both of them had a good correlation with RIA; y = 1.02x + 2.3, r=0.99 and Y=0.96x-0.38. The C.V.S. were 1.8 and 5.2% (intraassay), or 5.8 and 9.5% (interassay), respectively. 2. The EIA was carried out to test hCG patients whose urinary hCG by HAR was under the LH level. The values in 371 samples were under 2ng/ml, but those in 40 samples were higher than 2ng/ml (Max 15.8 ng/ml). Diagnosis by EIA distinguished recurrence from remission 2 month earlier than by HAR. The EIA was useful in the management of the disease.

Adult↗
PubMed1983

[Characterization of two choliocarcinoma cell lines and their sensitivity to MTX].

Both the sensitivity to MTX and hCG secretion were compared in two choriocarcinoma cell lines (BeWo and HCCM-5) and study on mechanisms about MTX-resistance was described. The uptake of nucleotides and protein precursors was decreased in dose-dependent manner in both cell lines when exposed to MTX, but HCCM-5 cells showed more sensitivity to MTX. In HCCM-5 cells, both hCG and hCG-beta levels in the medium were decreased with exposure to 10(-9)M MTX, but they tended to increase when exposed to higher concentration of MTX in contrast to the inhibition of 3H-thymidine uptake. However, in BeWo cells, an inverse relationship between the incorporation of 3H-thymidine and secretion of hCG was not clearly observed. The content of dihydrofolate reductase (DHFR) in HCCM-5 cells was about one-half of that in BeWo cells. Although the peak of 3H-MTX incorporation was observed at 120 minutes in both cell lines, HCCM-5 cells incorporated about 4 times higher 3H-MTX than BeWo cells. The difference of sensitivity to MTX between those two cell lines seems to be concerned with both the decrease of MTX transport and increase of intracellular DHFR levels.

Animals↗
PubMed1983

[MTX sensitivity and the mechanism of resistance of various choriocarcinoma cells in culture].

The sensitivity to methotrexate (MTX) and mechanisms of the drug resistance of seven kinds of human choriocarcinoma cell lines were studied in vitro. The results were as follows. Each cell line of HCCM-5 , BeWo, IMa, and NUC-1 secreted more than 200ng/10(6) cells/48 hours of human chorionic gonadotropin (hCG), whereas GCH-1, ENAMI-1, and SCH secreted less than 20ng/10(6) cells/48 hours. HCCM-5 cell line was the most sensitive to MTX judging from the inhibition of both 3H-thymidine uptake and cell growth in vitro. Each cell line of BeWo, IMa, and NUC-1 revealed sensitivity to 2 X 10(-8)M MTX, but such cell lines as GCH-1, ENAMI-1, and SCH showed resistance to MTX. The cell lines which revealed sensitivity to MTX incorporated more 3H-MTX and showed less intracellular dihydrofolate reductase activity than resistant cell lines.

Cell Line↗
PubMed1982

[Studies on the recurrent trophoblastic disease].

We studied the remission and the recurrent of trophoblastic disease treated in our clinic, during 1973 to 1980. 1) The remission and recurrent rates of 168 cases were 91.1% (153/168) and 5.2% (8/153) respectively. In these percentages, high risk was 65.9% (29/44) and 20.7% (6/29), low risk was 100% (124/124) and 1.6% (2/124), choriocarcinoma was 58.3% (21/36) and 28.6% (6/21), invasive mole was 100% (44/44) and 0, and undetermined was 100% (88/88) and 2.3% (2/88). 2) The interval to recurrence: 5 cases appeared under a year, 3 cases did over a year. And remission rate of recurrent case was (4/8), high risk was (2/6), and low risk was (2/2). 3) HCG-beta titers when U-hCG decreased under the LH levels was higher until 3 months in the recurrent case of high risk than that unrecurrent, while we did not recognize any differences after 3 months. Therefore criteria of remission in high risk would occurred on continuous LH levels of U-hCG for 3 months. 4) High risk has been treated by 3 courses of additional chemotherapy, but that when hCG-beta titer over 1.0ng/ml require more chemotherapy.

Adult↗
PubMed1982

Immunohistochemical detection of pregnancy-specific protein (SP1) and placenta-specific tissue proteins (PP5, PP10, PP11 and PP12) in ovarian adenocarcinomas.

By using an immunoglobulin-enzyme bridge method, pregnancy-specific beta 1-glycoprotein (SP1) and placenta-specific tissue proteins (PP5, PP10, PP11, PP12) were investigated in 15 cases of mucinous cystadenocarcinoma and 20 cases of serous cystadenocarcinoma. These proteins could be detected in the cytoplasm of some malignant cells. In mucinous cystadenocarcinomas, SP1, was present in 53.3% of cases, PP5 in 80.0%, PP10 in 20.0%, PP11 in 66.7% and PP12 in 46.7%. In serous cystadenocarcinomas, SP1 was present in 35.0% of cases, PP5 in 76.2%, PP10 in 9.5%, PP11 in 57.1% and PP12 in 23.8%. No proteins were detected in five normal ovaries. All control sections incubated with phosphate-buffered saline or normal, non-pregnant, non-immune rabbit serum in place of the first specific antiserum as well as with the antisera exhaustively absorbed with the corresponding purified antigens were negative for each protein. The detection rates are discussed in relation to the clinical stages and survival rates of the patients. This study suggests that these proteins, especially PP5 and PP11, may be useful as markers in monitoring patients with ovarian adenocarcinomas as well as for their early diagnosis.

Cystadenocarcinoma↗
PubMed1982

[Antitumor effect of interferon against human choriocarcinoma cell lines].

In this report, we describe the inhibitory effect of two kinds of human interferons, IFN-alpha and IFN-beta, on the growth of human choriocarcinoma cell lines in vitro and in vivo on comparing the other various cell lines derived from gynecologic malignancies. As compared to human endometrial (HEC-1B) or ovarian (HOC-21) adenocarcinoma cells which were highly resistant to the inhibitory effect of IFN-beta on the DNA synthesis at any doses up to 10,000U/ml, two human choriocarcinoma cell lines, BeWo and HCCM-5, and yolk sac tumor cell line YS-K were relatively sensitive. However, the inhibition was not dose-dependent. The growth of BeWo and HCCM-5 cells were also inhibited by either IFN-alpha or IFN-beta at concentration of 1,000U/ml and the inhibition became conspicuous when the treatment was prolonged to 4 days or more. When the hamsters transplanted with BeWo or HCCM-5 cells were treated with 10,000U IFN-beta on every day from the first till the 7th day after inoculation of cells, the tumor weights decreased to about one-half of those of non-treated controls. In contrast, the tumor weights were almost the same as non-treated controls when the animals were given with IFN-beta from the 7th day till the 13th day.

Animals↗