Assessment of luteinizing hormone receptor function in an endometrial cancer cell line, Ishikawa cells in response to human chorionic gonadotrophin (hCG)

Steroid hormones and human choriogonadotropin influence the distribution of alpha6-integrin and desmoplakin 1 in gland-like endometrial epithelial spheroids

In human glandular endometrial epithelial cells, desmosomal and adherens junction proteins have been shown to extend from a subapically restricted lateral position to the entire lateral membrane during the implantation window of the menstrual cycle. Similarly, a menstrual cycle stage-dependent redistribution of the extracellular matrix adhesion protein α6-integrin has been reported. These changes are believed to be important for endometrial receptiveness and successful embryo implantation. To prove the hypothesis that steroid hormones and human choriogonadotropin can induce the redistribution of these adhesion molecules, we used the human endometrial cell line Ishikawa in a 3D culture system. Gland-like spheroids were grown in reconstituted basement membrane (Matrigel™). The lumen-bearing spheroids were treated for 2 or 4 days with ovarian steroids or human choriogonadotropin and then assessed by immunofluorescence microscopy. In addition, human endometrial biopsies were obtained from patients, who were in therapy for assisted reproductive technology, and were examined in parallel. Lateral redistribution of the desmosomal plaque protein desmoplakin 1 was observed in the spheroids treated either with progesterone, medroxyprogesterone acetate or human choriogonadotropin. Furthermore, the extracellular matrix adhesion protein α6-integrin showed an increased lateral membrane localization upon gestagen stimulation in the 3D culture system. The results of this study demonstrate that the 3D endometrial Ishikawa cell culture might be suited as an experimental model system to prove the effect of hormonal changes like those occurring during the window of implantation.

The importance of hCG in human endometrial adenocarcinoma and breast cancer

Human chorionic gonadotropin (hCG) is a peptide hormone which plays an important role during pregnancy. But its impact is not limited to pregnancy; it also influences tumor formation and metastatic outgrowth, especially in endometrial adenocarcinoma and breast cancer. This review summarizes what has been written in the literature about the role of hCG as a tumor marker in these 2 gynecological malignancies and also about the signal transduction pathways in which hCG is involved. HCG can, on the one hand, be a marker for the progression of a malignant disease, and on the other hand, it may be a point for therapeutical intervention, so further research into this molecule would be very much worthwhile.

Anti-androgenic endocrine disrupting activities of chlorpyrifos and piperophos

The present work describes the screening and characterization of some common endocrine disrupting chemicals for their (anti)androgenic activities. Various chemicals (mostly pesticides and pharmaceuticals) were screened with the NIH3T3 cell line stably expressing human androgen receptor (hAR) and luciferase reporter gene for their ability to stimulate luciferase activity or inhibit the response that was evoked by 0.4nM testosterone. The most potent anti-androgenic compounds identified in our assay included chlorpyrifos, endosulfan and piperophos. Finally, the chemicals were analyzed for their effects on steriodogenesis in rat Leydig cells. Piperophos and chlorpyrifos showed a significant decrease in testosterone biosynthesis by Leydig cells. RT-PCR studies showed decrease in the expression of key steroidogenic enzymes: cytochrome P450scc, 3beta-HSD and 17beta-HSD and immunoblot analysis demonstrated a decrease in steroidogenic acute regulatory (StAR) protein expression by both these chemicals. Chlorpyrifos also showed a decrease in LH receptor stimulated cAMP production. In conclusion, we demonstrate that commonly used pesticides like chlorpyrifos and piperophos pose serious threat to male reproductive system by interfering at various levels of androgen biosynthesis.

Chorionic gonadotropin regulates prostaglandin E synthase via a phosphatidylinositol 3-kinase-extracellular regulatory kinase pathway in a human endometrial epithelial cell line: implications for endometrial responses for embryo implantation

Successful implantation necessitates modulation of the uterine environment by the embryo for a specific period of time during the menstrual cycle. Infusion of chorionic gonadotropin (CG) into the oviducts of baboons to mimic embryo transit induces a myriad of morphological, biochemical, and molecular changes in the endometrium. Endometrial epithelial cells from both baboons and humans when stimulated by CG in vitro, activates a cAMP-independent MAPK pathway leading to prostaglandin E(2) (PGE(2)) synthesis. This study shows that in the human endometrial cell line, HES, CG, acting via its G-protein coupled receptor, phosphorylates protein kinase B, c-Raf, and ERK1/2 in a phosphatidylinositol 3-kinase (PI3K)-dependent manner. Furthermore, ERK1/2 phosphorylation is independent of the signaling paradigms of Galpha(s), Galpha(I), and epidermal growth factor receptor (EGFR) transactivation, typical of gonadal cells, indicating an alternative signaling pattern in the endometrium. After phosphorylation by CG, ERK1/2 translocates to the nucleus in a time-dependent manner. Downstream of ERK1/2, CG activates the nuclear transcription factor, Elk1, also in a PI3K-MAPK-dependent manner. Lastly, we show that in HES cells, this pathway regulates the expression of the microsomal enzyme PGE(2) synthase (mPTGES), a terminal prostanoid synthase responsible for PGE(2) synthesis. CG regulates the mPTGES promoter and also induces mPTGES synthesis in HES cells via the PI3K-ERK1/2 pathway. We suggest that this alternative PI3K-ERK-Elk pathway activated by CG regulates prostaglandin production by the endometrial epithelium and serves as an early trigger to prepare the endometrium for implantation.