Clinical suppression of precocious puberty with cetrorelix after failed treatment with GnRH agonist in a girl with gonadotrophin-independent precocious puberty

The effect of GnRH antagonist cetrorelix on Wnt signaling members in pubertal and adult mouse ovaries

Wide application of gonadotropin-releasing hormone (GnRH) agonists and antagonists for clinical purposes determines their effects on ovarian signaling pathways. Our study aimed to determine the localization, expression levels of Wnt signaling members in the pubertal and adult mouse ovary and the impact of GnRH antagonist cetrorelix on these signaling members. 0.5 mg/kg of cetrorelix was injected to 3-and 6-week-old mice for 2 weeks. At the end of injection, ovaries from 5 (5Ce)- to 8-week (8Ce)-old mice were embedded in paraffin for immunohistochemistry and homogenized for western blot to compare with control (5C-8C) and sham groups (5S-8S). WNT2 and WNT4 showed higher expression in thecal and stromal cells in adult mouse ovaries and only WNT4 expression was affected by cetrorelix. FZD1 was localized mainly in oocytes of pubertal ovaries and granulosa cells and oocytes of adult ovaries. FZD1 was reduced by cetrorelix in pubertal ovaries. FZD4 was abundantly localized in thecal and stromal cells of all groups and protein level was not affected by cetrorelix. LRP-6 was expressed mainly in oocytes and stromal cells of pubertal, oocytes of adult ovaries and its expression was reduced by cetrorelix in adult ovaries. CTNNB1 intensity in granulosa cells was the lowest in pubertal and the highest in adult ovaries and its expression was decreased by cetrorelix in adult ovaries. Cetrorelix affected the expression of specific members of the Wnt signaling depending on the developmental stage of mice, pointing out its possible interaction with gonadotropins during pubertal and adult stages.

Drug Insight: clinical use of agonists and antagonists of luteinizing-hormone-releasing hormone

This article reviews the clinical uses of agonists and antagonists of luteinizing-hormone-releasing hormone (LHRH), also known as gonadotropin-releasing hormone. In particular, the state of the art treatment of breast, ovarian and prostate cancer, reproductive disorders, uterine leiomyoma, endometriosis and benign prostatic hypertrophy is reported. Clinical applications of LHRH agonists are based on gradual downregulation of pituitary receptors for LHRH, which leads to inhibition of the secretion of gonadotropins and sex steroids. LHRH antagonists immediately block pituitary LHRH receptors and, therefore, achieve rapid therapeutic effects. LHRH agonists and antagonists can be used to treat uterine leiomyoma and endometriosis; furthermore, both types of LHRH analogs are used to block the secretion of endogenous gonadotropins in ovarian-stimulation programs for assisted reproduction. The preferred primary treatment of patients with advanced, androgen-dependent prostate cancer is based on the periodic administration of depot preparations of LHRH agonists; these agonists can be likewise used to treat estrogen-sensitive breast cancer in premenopausal women. LHRH antagonists have been successfully used to treat prostate cancer and benign prostatic hypertrophy. Since receptors for LHRH are present on a variety of human tumors, (notably breast, prostate, ovarian, endometrial and renal cancers), cytotoxic therapy that targets these tumors with hybrid molecules of LHRH might be possible in the near future. Analogs of LHRH are now a well-established means of treating sex-steroid-dependent, benign and malignant disorders.

Treatment of central precocious puberty

The problems of central precocious puberty (CPP) are serious enough to the patient to deserve treatment. There is a general consensus among paediatric endocrinologists that the treatment of true CPP (i.e., in children young enough to have a formal diagnosis) is indicated in many cases. In children with modestly early puberty who are not fulfilling the diagnostic criteria, this is not the case. The treatment of choice is a gonadotropin-releasing hormone (GnRH) analogue. Prolonged analogues are more effective than short-acting ones and, most importantly, independent of patient compliance. Data on agonists have accumulated over two decades and evidence of effects is rich in girls but sparse in boys. GnRH agonists are generally effective and safe drugs; the suppression of puberty is reversible and there is much information on GnRH agonists for the treatment of CPP showing very few adverse effects and the effects on final height are well documented in girls < 6 years of age. There is some (but not highly convincing) evidence for their effect on final height for those of 6 - 8 years of age and there is no evidence for an increase in final height after the age of 8 years in girls. If a decision to have treatment is taken, treatment should start immediately as a possible benefit is less probable if the start of treatment is delayed. When treatment should be stopped is a matter of controversy. Combination with growth hormone increases final height, but the clinical relevance can be discussed as well as the health economy aspects. The limits of indications are still to be defined.