GnRH antagonist weakens endometrial stromal cells growth ability by decreasing c-kit receptor expression

BACKGROUND

Several surveys have reported that patients treated with gonadotropin-releasing hormone antagonist (GnRH-ant) protocol showed a significantly lower rate of implantation and clinical pregnancy compared to GnRH agonist (GnRH-a) protocol during in vitro fertilization-fresh embryo transfer. Subsequent studies imputed this poor outcome to the negative effects of GnRH-ant on endometrial receptive. However, the mechanisms were not fully understood.

METHODS

The clinical data of 2815 patients undergoing fresh embryo transfer in our center were analyzed. Human endometrial stromal cells (ESCs) from healthy women undergoing elective pregnancy termination of a normal pregnancy at 8-10 weeks gestation were treated with GnRH-analogs or imatinib (c-kit receptor inhibitor). CCK8 and Flow cytometry were used to investigated the growth ability of ESCs. Immunofluorescence staining and western blot was used to detected the target proteins.

RESULTS

The clinical data showed that the endometrial thickness on HCG Day were significantly lower in GnRH-ant group. Although no difference of embryo quality in these two groups, GnRH-ant group showed remarkably decreased rate of HCG positive, embryo implantation and pregnancy. Moreover, GnRH-ant significantly reduced the proliferation and induced the apoptosis of ESCs. Furthermore, the expression and activation of c-kit receptor, which played pivotal roles during embryo implantation, were observably decreased by GnRH-ant. Inhibiting the activation of c-kit by imatinib remarkably suppressed the proliferation and promoted the apoptosis of ESCs. Additionally, the phosphorylation of AKT and expression of Cyclin D1, which were closely related with cellular growth, were distinctly lessened after treating with imatinib.

CONCLUSIONS

In summary, our study showed that GnRH-ant weakened the activization of c-kit receptor by decreasing its expression, causing the impaired growth ability of ESCs. Our findings provided a new insight into the effects of GnRH-ant on endometrium.

Serum level of stem cell factor and its soluble receptor in aspirin-exacerbated respiratory disease

Aim: Stem cell factor (SCF) may be associated with inflammatory processes leading to aspirin-induced asthma. This study evaluated the relationship between serum level of SCF and its soluble receptor with aspirin-induced asthma. Methods & materials: Twenty-five patients and 25 healthy controls were enrolled in this study. The concentration of SCF and mast/stem cell growth factor receptor (C-kit) was determined in serum samples. Spirometry and rhinometry were performed to determine the severity of the disease. p < 0.05 were considered significant. Results: The serum levels of SCF and C-kit receptor were significantly higher in the case group. The serum SCF and C-kit level had a significant positive correlation with the severity of asthma, disease duration and nasal obstruction. Conclusion: Our findings suggest that SCF and C-kit receptors have a direct effect on the severity of aspirin-induced asthma.

An evaluation of masitinib for treating systemic mastocytosis

Introduction: Systemic Mastocytosis (SM) is a complex family of rare diseases, against which pharmacological therapies are still very few. It is a c-kit driven disease, whose disregulation leads to uncontrolled activation and proliferation of mast cells (MCs) with consequent release of effector molecules which are responsible for its clinical manifestations. Areas covered: Masitinib is a relatively new potential drug against SM and its chemical structure strictly derives from imatinib, the first tyrosine kinase inhibitor which entered the pharmaceutical market about 15 years ago. In this review, the authors present masitinib in all its properties, from chemistry to pharmacology and toxicity to its potential clinical application in SM, focusing the discussion on the few clinical trials in which it has been involved, with a particular attention on the still open challenge to determine how to measure the response to therapy. Expert opinion: In spite of their similarity in chemistry and biological activity against submolecular targets, masitinib is much more selective towards c-kit receptors than other tyrosine kinases, such as Bcl-Abl. Furthermore, its ability to inhibit degranulation, cytokine production and MCs migration from bone marrow gives it a great chance to become an important therapeutic option for selected SM patients.