gnrh receptor
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Relugolix is a gonadotropin-releasing hormone (GnRH) receptor antagonist used in the treatment of several hormone-responsive conditions. It was first approved in Japan in 2019, under the brand name Relumina, for the symptomatic treatment of uterine fibroids, and more recently by the United States' FDA in 2020, under the brand name Orgovyx, for the treatment of advanced prostate cancer. Relugolix has also been studied in the symptomatic treatment of endometriosis. Relugolix is the first (and currently only) orally-administered GnRH receptor antagonist approved for the treatment of prostate cancer-similar therapies such as degarelix require subcutaneous administration-and therefore provides a less burdensome therapeutic option for patients who might otherwise require clinic visits for administration by healthcare professionals.In addition to its relative ease-of-use, relugolix was shown to be superior in the depression of testosterone levels when compared to leuprolide, another androgen deprivation therapy used in the treatment of prostate cancer1,2

Abstract Background Uterine leiomyomas are the most common neoplasm affecting women and frequently cause heavy menstrual bleeding and pain. Gonadotropin-releasing hormone (GnRH) receptor antagonists provide fast symptom relief and show promise as a medical (non-surgical) treatment option and as a presurgical treatment to reduce leiomyoma size. The aim of this study was to evaluate the efficacy and safety of three dose levels of oral relugolix, a small molecule GnRH receptor antagonist, in Japanese women with uterine leiomyomas and heavy menstrual bleeding. Methods This phase 2, multicenter, double-blind, parallel-group study was conducted at 36 sites in Japan in women with uterine leiomyomas and heavy menstrual bleeding, defined as a pictorial blood loss assessment chart (PBAC) score of ≥ 120 in one menstrual cycle. Patients were randomized 1:1:1:1 to relugolix 10, 20, or 40 mg, or placebo, orally once daily for 12 weeks. The primary endpoint was the proportion of patients with a total PBAC score of < 10 from week 6 to 12. A sample size of 50 patients per group was estimated to provide ≥ 95% power, based on the comparison of relugolix 40 mg with placebo using a chi-square test with a significance level of 5% (two-sided). Results From November 2011 to September 2012, 216 patients were randomized and 214 patients (99.1%) were analyzed. The proportion (difference vs. placebo) of patients that achieved the primary endpoint in the placebo and 10-, 20-, and 40-mg relugolix groups were 0%, 20.8% (95% confidence interval [CI]: 9.3–32.3, P < .001), 42.6% (95% CI: 29.4–55.8, P < .001), and 83.3% (95% CI: 73.4–93.3, P < .001), respectively. Though treatment-emergent adverse events were similar between the 20- and 40-mg groups, the incidence rates were more frequent compared with the placebo group. Most of these adverse events were mild or moderate in intensity. Conclusions Relugolix decreased menstrual blood loss in women with uterine leiomyomas in a dose–response manner, and was generally well tolerated. Clinical trial registration: ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT01452659, NCT01452659 (registered 17/10/2011); JAPIC Clinical Trial Information, https://www.clinicaltrials.jp, JapicCTI-111590 (registered 31/08/2011).

GnRH1 and GnRH2 receptors (provisonal nomenclature [39], also called Type I and Type II GnRH receptor, respectively [85]) have been cloned from numerous species, most of which express two or three types of GnRH receptor [85, 84, 114]. GnRH I (p-Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2) is a hypothalamic decapeptide also known as luteinizing hormone-releasing hormone, gonadoliberin, luliberin, gonadorelin or simply as GnRH. It is a member of a family of similar peptides found in many species [85, 84, 114] including GnRH II (pGlu-His-Trp-Ser-His-Gly-Trp-Tyr-Pro-Gly-NH2 (which is also known as chicken GnRH-II). Receptors for three forms of GnRH exist in some species but only GnRH I and GnRH II and their cognate receptors have been found in mammals [85, 84, 114]. GnRH1 receptors are expressed by pituitary gonadotrophs, where they mediate the effects of GnRH on gonadotropin hormone synthesis and secretion that underpin central control of mammalian reproduction. GnRH analogues are used in assisted reproduction and to treat steroid hormone-dependent conditions [58]. Notably, agonists cause desensitization of GnRH-stimulated gonadotropin secretion and the consequent reduction in circulating sex steroids is exploited to treat hormone-dependent cancers of the breast, ovary and prostate [58]. GnRH1 receptors are selectively activated by GnRH I and all lack the COOH-terminal tails found in other GPCRs. GnRH2 receptors do have COOH-terminal tails and (where tested) are selective for GnRH II over GnRH I. GnRH2 receptors are expressed by some primates but not by humans [88]. Phylogenetic classifications divide GnRH receptors into three [85] or five groups [129] and highlight examples of gene loss through evolution, with humans retaining only one ancient gene. The structure of the GnRH1 receptor in complex with elagolix has been elucidated [132].

Cancer is the uncontrolled division of abnormal cells in a specific organ. Globally, about 1 in 6 deaths is due to cancer. Despite the plethora of research being undertaken worldwide to find a cure for cancer, it remains a significant challenge. Cancer targeting via agents designed to interfere with some specifically or highly expressed molecules in cancer cells has been a shift in the treatment of various forms of cancers. The development of drug delivery systems, specifically to cancer cells, is a common approach that succeeded in increasing the efficacy and reducing the side effects of different anticancer agents. Gonadotropin-releasing hormone (GnRH) is a naturally occurring hormone with receptors overexpressed in many types of cancers related or unrelated to the reproductive system. Several drug delivery systems were developed using GnRH derivatives as targeting agents. In this review, we first discuss the role of GnRH and its receptors in cancer. Then, we provide a detailed insight into different delivery systems developed using GnRH derivatives as targeting agents in various types of GnRH receptor overexpressing cancers. Some promising findings from these studies indicate that GnRH receptor targeting is a potential strategy to efficiently guide anticancer therapeutics, diagnostic agents, and nucleic acids directly to cancer cells. Lastly, some limitations of the current research and suggestions for more successful outcomes in clinical trials of these delivery systems are highlighted.

The choice of ovarian stimulation protocols in assisted reproduction technology (ART) cycles for low ovarian reserve patients is challenging. Our previous report indicated that the gonadotrophin-releasing (GnRH) agonist (GnRHa) protocol is better than the GnRH antagonist (GnRHant) protocol for young age poor responders. Here, we recruited 269 patients with anti-Müllerian hormone (AMH) < 1.2 ng/mL undergoing their first ART cycles for this nested case-control study. We investigated the genetic variants of the relevant genes, including follicular stimulating hormone receptor (FSHR; rs6166), AMH (rs10407022), GnRH (rs6185), and GnRH receptor (GnRHR; rs3756159) in patients <35 years (n = 86) and patients ≥35 years of age (n = 183). Only the genotype of GnRHR (rs3756159) is distributed differently in young (CC 39.5%, CT/TT 60.5%) versus advanced (CC 24.0%, CT/TT 76.0%) age groups (recessive model, p = 0.0091). Furthermore, the baseline luteinizing hormone (LH) levels (3.60 (2.45 to 5.40) vs. 4.40 (2.91 to 6.48)) are different between CC and CT/TT genotype of GnRHR (rs3756159). In conclusion, the genetic variants of GnRHR (rs3756159) could modulate the release of LH in the pituitary gland and might then affect the outcome of ovarian stimulation by GnRHant or GnRHa protocols for patients with low AMH levels.