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A high-grade uterine leiomyosarcoma with human chorionic gonadotropin production.

Ectopic human chorionic gonadotropin production has been described in a wide variety of non-germ cell tumors, particularly in epithelial tumors, but rarely in sarcomas. In this report, we describe the case of 49-year-old woman with a history of "uterine fibroids," who presented with vaginal bleeding and a positive urine pregnancy test. After pregnancy was ruled out by ultrasound, the patient underwent a laparotomy and hysterectomy for a presumptive diagnosis of "fibroids" and was found to have carcinomatosis at the time of the surgery. Therefore optimal debulking of tumors was performed. Two weeks later, the patient developed a small bowel obstruction, which apparently was due to rapid recurrence of tumors in the abdomen, and soon afterwards she died. Microscopically, the resected pelvic mass was composed of highly atypical and pleomorphic spindle cells admixed with many multinucleated giant cells. The tumor had a high mitotic rate along with areas of hemorrhage and necrosis. Immunohistochemically, the tumor cells were positive for vimentin, desmin, smooth muscle actin, and beta-human chorionic gonadotropin, and were negative for epithelial membrane antigen, keratin AE1/3, S-100, CD31, CD117, Ber-EP4, WT-1, estrogen and progesterone receptors. The majority of cells, including the multinucleated giant cells, were strongly immunoreactive for beta-human chorionic gonadotropin. Only three cases of leiomyosarcomas with beta/human chorionic gonadotropin production have been described in the literature, and all three cases had extrauterine origin. Our case, to the authors' best knowledge, is the first uterine leiomyosarcoma with prominent beta/human chorionic gonadotropin production.

Actins↗

The structures of the serine-linked sugar chains on human chorionic gonadotropin.

The human chorionic gonadotropin beta-subunit tryptic COOH-terminal peptide (residues 123-145) which contains 3 serine-linked sugar chains was isolated. The sugar chains were cleaved by beta-elimination and then separated by gel filtration. The peaks were pooled and their compositions determined. The products of serial glycosidase digestion and periodate oxidation of the intact glycopeptide were also characterized. Of the serine-linked sugar chains, 13% were the hexasaccharide NeuAc alpha 2,3 Gal beta 1,3 (NeuAc alpha 2,3 Gal beta 1,4 GlcNAc beta 1,6) GalNAc, 34% the tetrasaccharide NeuAc alpha 2,3 Gal beta 1,3 (NeuAc alpha 2,6) GalNAc, 43% the trisaccharide NeuAc alpha 2,3 Gal beta 1,3 GalNAc and 10% the disaccharide NeuAc alpha 2,6 GalNAc.

Carbohydrate Conformation↗

The molar vesicle fluid contains the beta-core fragment of human chorionic gonadotropin.

The human chorionic gonadotropin (hCG) beta-core fragment (beta-CF) is a major molecular form of hCG beta subunit (hCGbeta) immunoreactivity in the urine of pregnant women and patients with trophoblastic disease. The majority of evidence supports the fact that the beta-CF is a degradative product of intact hCG and free hCGbeta in the kidneys. We found a beta-CF-like substance in the fluid of molar vesicles from a patient with complete hydatidiform mole. The molar fluid beta-CF (mbeta-CF) was indistinguishable from the beta-CF in the patient's urine (ubeta-CF) by immunoreactivity and by elution profile on gel chromatography. The binding study to lectins, however, showed that mbeta-CF contains a carbohydrate moiety that differs from that of ubeta-CF. Immunohistochemistry with anti-beta-CF antibody demonstrated a strong immunoreactivity in a large number of macrophages in the molar villous stroma. In vitro incubation of intact hCG with peritoneal macrophages showed a slow increase of intact hCG in the cell cytosol with the appearance of beta-CF-like substance in the cell supernatant. In conclusion, the source of beta-CF in molar fluid is likely to be macrophages existing in the villous stroma. Thus macrophages may ingest intact hCG and act as a local regulator of gonadotropic hormones.

Body Fluids↗

The effect of human chorionic gonadotropin, dibutyryl cyclic adenosine 3',5'-monophosphate, prostaglandins, and 25-hydroxycholesterol on acute progesterone secretion by dissociated rabbit luteal cells in vitro: evidence for independent effect of human chorionic gonadotropins and lipoproteins.

Although estradiol is the established luteotropic hormone in the rabbit, the corpus luteum also contains a luteinizing hormone (LH)-activated adenylate cyclase system and cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase, which suggests that LH and cAMP may play a physiological role in regulating luteal progesterone production. The present study examined whether human chorionic gonadotropin (hCG) and cAMP derivatives stimulate progesterone production by dispersed rabbit luteal cells in static and perifusion incubations. Results of this study show that progesterone production by rabbit luteal cells is significantly stimulated (p less than 0.05) by hCG concentrations at or greater than 0.1 IU/ml or by dibutyryl cAMP concentrations at or greater than 5 mM. Both agents produce maximal stimulations of approximately 4-fold. However, neither prostaglandin E2 or F2 alpha at concentrations of 0.1-3.0 micrograms/ml altered progesterone secretion. When luteal cells were incubated with maximal concentrations of hCG and lipoproteins together, the resultant progesterone secretion was additive. This suggests that the effects of hCG and lipoprotein are independent. Both responses could be blocked completely by cycloheximide (10(-4) M), and thus appear to be dependent on protein synthesis. The cholesterol derivative 25-hydroxycholesterol (20 micrograms/ml) partially overcame the steroidogenic block by cycloheximide, suggesting that transport of cholesterol, regardless of its origin, into mitochondria was an essential protein-mediated event in these cells. Inhibition of the side-chain-cleavage enzyme by aminoglutethamide blocked progesterone production by rabbit luteal cells in vitro. Although estradiol may dominate in the regulation of luteal progesterone production physiologically, this study clearly demonstrates that potential mechanisms do exist in the rabbit corpus luteum for cAMP-mediated stimulation of progesterone production in the rabbit.

Animals↗

Effects of fetal sex, stage of gestation, dibutyryl cyclic adenosine monophosphate, and gonadotropin releasing hormone on secretion of human chorionic gonadotropin by placental explants in vitro.

Explants from 16 term and 6 midtrimester placentas were cultured for 6 days. Statistically significant increases in secretion of human chorionic gonadotropin occurred in control medium cultures of both term and midtrimester explants during the 6-day culture period (p less than 0.01). Statistically significant increases in secretion of human chorionic gonadotropin were produced by 2 mmol/L dibutyryl cyclic adenosine monophosphate in both the term (p less than 0.01) and the midtrimester (p less than 0.01) explants. There was no effect of gonadotropin releasing hormone. The ratio of human chorionic gonadotropin secretion from midtrimester explants to that from term explants varied under different conditions, dropping from twentyfold in day 1 cultures to elevenfold for maximum secretion produced after culture in control medium for up to 6 days. A further drop in the ratio to fourfold was observed for the maximal response to 2 mmol/L dibutyryl cyclic adenosine monophosphate treatment. Explants from term female infants produced significantly more human chorionic gonadotropin than those from term male infants (p less than 0.05), but the sex difference disappeared after stimulation with 2 mmol/L dibutyryl cyclic adenosine monophosphate.

Bucladesine↗

Human chorionic gonadotropin in BeWo trophoblastic cells after 12 years in continuous culture: retention of intact human chorionic gonadotropin secretion in mechanically versus enzyme-dispersed cells.

Gel filtration and radioimmunological studies were used to demonstrate that BeWo malignant trophoblastic cells, subcultured for more than 12 yr as roller tube colonies using dissection by scalpel, retained the ability to secrete large quantities of intact hCG. By contrast, BeWo cells that had been subcultured weekly for 12 hr using proteolytic enzyme dispersion lost their ability to secrete intact hCG. Rather, a large form of hCG-alpha was the major secretory product, along with lesser amounts of heterogeneous low molecular weight forms of hCG-beta. The gradual loss of hormone secretory ability and fidelity of hormone product by cells in continuous culture is a well known phenomenon. Our results suggest that the habitual use of trypsin-EDTA to subculture cells may accelerate this process.

Cell Line↗

Suppression of antitumor lymphocyte mediated cytotoxicity by human chorionic gonadotropins.

The effect of human chorionic gonadotropin on the in vitro cytotoxicity of lymphocytes against human transitional cell carcinoma cells was studied in 9 patients using the microcytotoxicity assay. Lymphocytes from 6 patients were cytotoxic against transitional cell carcinoma cells. However, in the presence of human chorionic gonadotropin the cytotoxicity of these lymphocytes against transitional carcinoma cells was diminished. Human chorionic gonadotropin alone or in combination with non-cytotoxic lymphocytes did not change the growth of target cells and human chorionic gonadotropin did not have a direct toxic effect on lymphocytes alone. These results demonstrate that human chorionic gonadotropin can inhibit the cytotoxic action of lymphocytes against human tumor cells in vitro. Human chorionic gonadotropin may contribute to the poor prognosis associated with certain human chorionic gonadotropin-secreting human tumors.

Carcinoma, Transitional Cell↗

Expression of variant luteinizing hormone/chorionic gonadotropin receptors and degradation of chorionic gonadotropin in human chorionic villous macrophages.

Human gonads and non-gonadal organs/tissues express luteinizing hormone/chorionic gonadotropin (LH/CG) receptors. This study aimed to identify the LH/CG receptors and to clarify their function in human placental chorionic villous macrophages. Macrophages as well as syncytiotrophoblasts of human chorionic villous tissues were immunohistochemically positive for LH/CG receptor throughout gestation. By reverse transcription-nested polymerase chain reaction methods, villous macrophages were shown to express a variant type of LH/CG receptor, the sequencing of which revealed a deletion of exon 9. For experiments in vitro, a monocyte-macrophage cell line, THP-1, was transfected with vector alone, wild-type LH/CG receptor, and exon 9-deleted LH/CG receptor after phorbol 12-myristate 13-acetate (PMA) treatment. Non-PMA-treated THP-1 cells transfected with vector alone were also examined. THP-1 cells expressed exon 9-deleted LH/CG receptor after treatment with PMA. After the cells of the four groups were cultured in medium containing intact human CG (hCG), the concentrations of hCG and its beta-core fragment (beta-CF) were measured in the supernatant of the culture medium and in the cell cytosol. Time-dependent hCG uptake was observed in both non-PMA-treated and PMA-treated THP-1 cells, suggesting that the variant receptor is not directly involved in the ingestion of hCG. The degradation of hCG and excretion of beta-CF were progressed in PMA-treated cells but not in the un-treated cells. In the cell cytosol, the ratio of beta-CF and hCG concentrations (beta-CF/hCG) was significantly higher in the PMA-treated cells than in non-PMA-treated cells; however, it did not differ between the PMA-treated cells transfected with exon 9-deleted receptor and those transfected with vector alone. Macrophages may express the variant receptor in order to recognize the intracytoplasmic hCG and transport it to the lysosome. Among the two PMA-treated cells, the ratio was lower in those transfected with wild-type receptor. The expression of the variant receptor may modulate the degradation of hCG but be reduced by expression of the wild-type receptor in its lacking macrophages. Our data suggest a potentially important role for exon 9-deleted LH/CG receptors expressed in human placental villous macrophages in the local metabolism of hCG.

Base Sequence↗

Effects of diacylglycerol and gonadotropin-releasing hormone on human chorionic gonadotropin release by cultured trophoblast cells.

The effect of activation of calcium- and phospholipid-dependent protein kinase (protein kinase C) on human chorionic gonadotropin (hCG) release by cultured trophoblast cells was studied and a role of protein kinase C in the GnRH-mediated hCG release was also evaluated. Both GnRH and 1-oleoyl-2-acetylglycerol (OAG), a protein kinase C activator, stimulated hCG release after 3 h incubation in a dose-dependent manner with ED50 of 55 nmol/l and 4.0 nmol/l, respectively. A tumor-promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) also stimulated hCG release while two non-tumor-promoting compounds, phorbol and 4 alpha-phorbol, failed to stimulate hCG release. hCG release by maximal effective dose of GnRH (10 mumol/l) or OAG (1 mumol/l) was further stimulated when cells were incubated with same concentrations of GnRH and OAG. OAG-stimulated hCG release was completely inhibited by a protein kinase C inhibitor, H-7, with ID50 of 23 nmol/l while H-7 did not affect GnRH-mediated hCG release. These results indicate that GnRH-stimulated hCG release is not mediated by protein kinase C pathway, however, the secretion of hCG is also regulated by the mechanism that involves protein kinase C activation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Effects of zeranol on reproduction in beef bulls: luteinizing hormone, follicle-stimulating hormone, and testosterone secretion in response to gonadotropin-releasing hormone and human chorionic gonadotropin.

Effects of zeranol on the maturation of the adenohypophyseal-gonadal axis were studied in beef bulls. Calves were implanted with 36 mg of zeranol at 3-month intervals from birth through 6 months of age (group 2, n = 10) or were not treated (control group 1, n = 10). After 9 months, group-2 calves were given implants of 36 mg of zeranol at 3-month intervals through 18 months of age (group 2B, n = 5) or were not reimplanted (group 2A, n = 5). Areas under the curves outlined by concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone for 6 hours after the administration of 100 micrograms of gonadotropin-releasing hormone (GnRH) were calculated. Gonadotropin-releasing hormone was administered at 3-month intervals from 1.5 through 19.5 months of age. Areas under the curves for concentrations of testosterone for 4 hours after the administration of 10,000 IU of human chorionic gonadotropin (HCG) at 4.5, 7.5, and 10.5 months or 1,000 IU at 13.5 and 16.5 months of age also were calculated. The amount of FSH released was greater (P less than 0.05) for group-2 than for group-1 calves at 4.5 and 7.5 months of age. The amount of FSH released in groups 2A and 2B tended (P less than 0.10) to be greater than that for group 1. Significant differences between groups 2A and 2B were not observed. The amount of LH released at 7.5 months of age was less for groups 1 and 2 than that at earlier ages, and the decrease was greater (P less than 0.05) for group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of chronic hyperprolactinemia in mice on plasma gonadotropin concentrations and testicular human chorionic gonadotropin binding sites.

Effects of artificially induced hyperprolactinemia in male DBA/2 mice were studied by transplanting four pituitary glands under the kidney capsules. After 52--57 days the animals were sacrificed, and tissue and plasma samples were obtained. Plasma concentrations of FSH and LH were significantly higher in pituitary-grafted mice than in sham-operated controls. Testicular LH/human chorionic gonadotropin (hCG) binding, measured via use of [125I]iodo-hCG, was significantly depressed both on a per milligram protein and per testes basis in hyperprolactinemic mice. Coincident with decreased hCG binding was a significantly diminished ability of decapsulated testes to produce testosterone in response to hCG in vitro. However, testosterone production by unstimulated hyperprolactinemic mouse testes was normal. Significantly increased body, seminal vesicle, and adrenal weights were also present in hyperprolactinemic mice. The data indicate that hyperprolactinemia in mice is associated with decreased testicular LH/hCG binding and a concomitant decrease in the responsiveness to hCG in vitro. These actions may be mediated by increased plasma LH concentrations.

Animals↗

Effect of gonadotropin-releasing hormone and human chorionic gonadotropin on cows with ovarian follicular cysts.

Ovarian follicular cysts of cattle were defined as follicular structures (larger than or equal to 2.5 cm, diameter) which persisted for 10 days or longer in the absence of functional luteal tissue. Thirty dairy cows with ovarian follicular cysts were allotted to 6 groups (5 cows per group) and each was given 0 (saline solution), 25, 50, 100, 150, or 250 mug of gonadotropin-releasing hormone (GnRH) by intramuscular (IM) injection. Samples of blood were collected before GnRH was injected (0 hour), at 0.25, 0.50, 0.75, 1, 2, 3, and 4 hours, and at 1, 7, 11, 15, and 20 days after treatment. Five additional cows with follicular cysts were treated IM with 10,000 units of human chorionic gonadotropin (HCG), and blood sample collections were made before treatment (0 hour) and on days 1, 7, 11, 15, and 20 after treatment. Serum luteinizing hormone (LH) concentration was not altered in cows given saline solution, but was increased significantly in cows given any of the doses of GnRH (in a dose-related manner). Peak LH responses occurred about 2 hours after GnRH was given, and by 4 hours LH was beginning to decrease. Serum progesterone concentrations increased by more than 2.0 ng/ml by day 11 after treatment in 18 of 20 cows treated with 50, 100, 150, or 250 mug of GnRH. Progesterone responses in these cows were greater (P less than 0.05) than in cows given saline solution or a 25-mug dose of GnRH. Mean progesterone response to the 4 large doses of GnRH was similar in magnitude and duration to serum progesterone changes during the leutal phase of the bovine estrous cycle. After cows were treated with HCG, serum progesterone values were similar to those in cows given GnRH (50 to 250 mug).

Animals↗

Differential actions of gonadotropin-releasing hormone and human chorionic gonadotropin on interstitial fluid volume and immunoglobulin G concentrations in adult rat testis.

Gonadotropin-releasing hormone (GnRH) agonists regulate testicular interstitial fluid (tIF) volume, most probably via specific receptors on Leydig cells. The aim of this study was to confirm the interaction between GnRH and Leydig cells in regulation of testicular fluid, and to examine the effects on serum proteins in testis. Unilateral intratesticular injection of a GnRH agonist (100 ng/testis) caused a 50% reduction in tIF volume within 2 hours. Destruction of Leydig cells by treatment with ethane dimethane sulfonate also caused a similar decline in tIF volume; however, GnRH agonist treatment had no additional influence on this response in Leydig cell-depleted testes. GnRH agonist treatment had no effect on serum protein permeability in testis as indicated by maintenance of the tIF/serum immunoglobulin G (IgG) concentration gradient. Injection of human chorionic gonadotropin (hCG, 100 IU) had no effect on tIF volume at 2 hours, but increased the permeability of the testicular vasculature to serum IgG. At 20 hours after hCG injection, tIF volume was increased twofold, while the testicular permeability barrier to IgG appeared to have been restored. These data indicate that the acute inhibitory action of GnRH on vascular fluid permeability is dependent upon Leydig cells, confirming that these cells are the primary site of GnRH action on testicular vasculature. The data also indicate that supraphysiological doses of hCG cause a rapid increase in testicular permeability to serum proteins, which occurs prior to the well-characterized stimulation of tIF volume. These data provide further evidence that the concentration of serum proteins in tIF and the volume of tIF are both under regulatory control involving Leydig cells, but are independently regulated.

Animals↗