Fertility Preservation Methods in Childhood and Adolescence Cancers: A Review.

In childhood and adolescence cancers; survival rates increase with the use of treatment options such as chemotherapy, radiotherapy and hematopoietic stem cell transplantation. One of the long-term effects of primary disease and cancer treatment is the irreversible damage to gonadal tissues, resulting in impaired fertility. Especially chemotherapeutic drugs; causes germ cell defect, affects the secretion of pituitary hormone, and also damages the anatomical structures of internal genital structures such as the uterus. Gonadal preservation methods are limited in prepubertal male patients. It is a good option to place the testicles in a different area before radiotherapy. Before chemotherapy or whole body irradiation, freezing of testicular tissue and ensuring pregnancy from frozen tissue is still in the experimental stage. After the ejaculation begins, obtaining and storing sperm is successfully done. A limited number of pregnancies were obtained oocytes frozen ovaries in the prepubertal girls. It is possible to freeze oocytes after puberty begins. In addition, recently, as a noninvasive method, gonadotropin-releasing hormone (GnRH) analogues have been used successfully, as it suppresses the hypothalamic-pituitary-gonadal axis and protects germ cells from cytotoxic effects. This article aims to provide information on fertility preservation methods in patients receiving childhood cancer treatment.

Precocious puberty: diagnosis and management

Precocious puberty is commonly defined as puberty that starts before age 8 years in girls and 9 years in boys. The causes of it may range from a variant of normal development to various pathologic conditions. The etiology of precocious puberty is classified by the underlying pathogenesis into gonadotropin dependent central precocious puberty and peripheral precocious puberty which is independent of gonadotropin but due to different other causes. Variants of precocious puberty include premature thelarche, premature puberche and isolated premature menarche which imply onset of isolated changes without any other signs of sexual development. Precocious puberty might have an impact on final stature owing to premature epiphyseal fusion and also it has got influence on psychosocial wellbeing. Evaluation includes a detailed history, physical examination, biochemical testing and imaging directed towards suspected etiology. Gonadotropin releasing hormone (GnRH) analogues are effective for treatment of central precocious puberty. Treatment of peripheral precocious puberty should be based on the specific cause. Pubertal variants are usually non-progressive and need no treatment but should be monitored carefully. BIRDEM Med J 2022; 12(1): 62-69

Preparation of Long-acting Somatostatin and GnRH Analogues and their Applications in Tumor Therapy

Hormonal drugs are essential treatment options for some hormone-dependent or hormone-sensitive tumors. The common dosage forms of hormonal drugs have a short half-life. Hence, frequent administration is needed, which results in poor patient compliance. Nevertheless, using drug delivery technology, somatostatin analogues (SSAs) and gonadotropin-releasing hormone (GnRH) analogues are prepared into long-acting formulations that can significantly prolong the action time of these drugs, reducing medication frequency and increasing patient compliance. Such drugs are advantageous when treating acromegaly, gastroenteropancreatic neuroendocrine tumors (GEP-NETs), breast cancer, prostate cancer, and other diseases having a relatively long course. SSAs and GnRH analogues are two typical hormonal drugs, the long-acting formulations of which are essential in clinical practice. This review summarized the preparation methods and clinical application of long-acting formulations in cancer. Further, the action mechanism and new research of SSAs and GnRH analogues were discussed, and suggestions related to the development of long-acting SSAs and GnRH analogues were provided.

Regulation of FSH Synthesis by Differentially Expressed miR-488 in Anterior Adenohypophyseal Cells

Gonadotropin-releasing hormone (GnRH), which is synthesized and released by the hypothalamus, promotes the synthesis and secretion of follicle-stimulating hormone (FSH), thereby regulating the growth and reproduction of animals. GnRH analogues have been widely used in livestock production. MiRNAs, which are endogenous non-coding RNAs, have been found to play important roles in hormone regulation and other physiological processes in recent years. However, the roles of miRNAs in GnRH-mediated regulation of FSH secretion have rarely been studied. Herein, we treated bovine anterior adenohypophyseal cells with an exogenous GnRH analogue and found that miR-488 was differentially expressed. Through a combination of TargetScan prediction and dual luciferase reporter analysis, miR-488 was confirmed to be able to target the FSHB gene. Based on this finding, we verified the expression of Fshβ and Lhβ mRNA in the rat adenohypophysis before and after exogenous GnRH treatment in vivo and in vitro. Experiments on rat anterior adenohypophyseal cells showed that overexpression of miR-488 significantly inhibited Fshβ expression and FSH synthesis, while knockdown of miR-488 had the opposite effects. Our results demonstrate that GnRH relies on miR-488 to regulate FSH synthesis, providing additional useful evidence for the significance of miRNAs in the regulation of animal reproduction.

Conventional GnRH Antagonist Protocols Versus GnRH Agonist Long Protocol on IVF/ICSI Outcomes in Women With Polycystic Ovary Syndrome: A Systematic Review and Meta- Analysis of Randomized Controlled Trials

BackgroundGonadotropin-releasing hormone (GnRH) analogues are commonly used in clinical practice to prevent premature luteinizing hormone (LH) surge during In-Vitro Fertilization/ Intra-Cytoplasmic Sperm Injection (IVF/ICSI) cycles. This review aimed to summarize the available evidence comparing the effects of conventional GnRH antagonist protocols, the most commonly used GnRH antagonist protocols, and GnRH agonist protocols on IVF/ICSI outcomes in women with polycystic ovary syndrome (PCOS). MethodsA comprehensive electronic search was carried out in Pubmed, Cochrane CENTRAL, Scopus, Web of Science, CINAHL, TRIP, ClinicalTrials.gov and ISRCTN registry from inception until 24 November 2020 without any language or date restrictions. In addition, reference lists of eligible studies and previous meta-analyses were hand-searched to identify relevant studies. Eligible randomized controlled trials were those designed to compare the effects of conventional GnRH antagonist protocols and GnRH agonist protocols on IVF/ICSI outcomes in PCOS subjects. The Cochrane ROB 2.0 tool was used to assess the risk of bias of each study, and the GRADE assessment was used to evaluate the overall quality of evidence. Data synthesis and analyses were done using Review Manager 5.3 with the assistance of Revman Web. A random-effects model was used for all meta-analysis. Dichotomous outcomes were reported as Relative Risk (RR) and continuous outcomes as Weighted Mean Difference (WMD), both with 95% CIs. 2 Resultswe included ten studies with 1214 randomized PCOS women. Using GnRH antagonist protocols led to a significantly shorter stimulation duration (WMD=-0.91; 95% CI: [-1.45 to-0.37] day, P=0.0009), lower gonadotropin consumption (WMD=-221.36; 95% CI: [-332.28 to-110.45] IU, P< 0.0001), lower E2 levels on hCG day (WMD=-259.21; 95% CI: [-485.81 to-32.60] pg/ml, P=0.02), thinner endometrial thickness on hCG day (WMD=-0.73; 95% CI: [-1.17 to-0.29] mm, P=0.001), lower number of retrieved oocytes (WMD=-1.82; 95% CI: [-3.48 to-0.15] oocytes, P=0.03), and lower OHSS rate (RR= 0.58; 95% CI: [0.44 to 0.77], P=0.0002). However, no significant differences in live birth rate, clinical pregnancy rate, ongoing pregnancy rate, multiple pregnancy rate, miscarriage rate and cycle cancellation rate were seen between the GnRH antagonist protocols and the long GnRH agonist one. Although more cycles were cancelled due to poor ovarian response in the GnRH antagonist protocol (RR= 4.63; 95% CI: [1.49 to 14.41], P=0.008), similar rates of cancellation due to risk of OHSS were noticed in both groups. DiscussionThe differences in IVF/ICSI outcomes may arise from the different patterns of gonadotropins suppression that the GnRH analogues exhibit during the early follicular phase of IVF/ICSI cycles and the divergent direct impacts of these analogues on ovaries and endometrial receptivity. The main evidence limitation was Imprecision. ConclusionsConventional GnRH antagonist protocols represent a safer and more cost-effective treatment choice for PCOS women undergoing IVF/ICSI cycles than the standard long GnRH agonist protocol without compromising the IVF/ICSI clinical outcomes.

Genetic Predisposition and Chemotherapeutic Approaches Including Oncolytic Virus for the Treatment of Prostatic Adenocarcinoma

Among the leading causes of cancer mortality, prostatic adenocarcinoma (PaC) is at second to lung carcinoma, but it is the most commonly happening non-cutaneous malignancy in elderly men in the world. Therapeutic options for PaC depend on age, growth &amp; stage of malignancy, the desired outcomes and shortcomings of available treatment, estimated cost and patient compliance. Patients older than 60 years with a sluggish localized tumor may be placed on active surveillance, otherwise go with transurethral resection of the prostate (TURP), prostate artery embolization (PAE) and pelvic lymphadenectomy with/without radiation therapy. For metastatic PC androgen-deprivation therapy is an option with or without surgery. These agents decline the body&rsquo;s testosterone production or block its activity by gonadotropin- releasing hormone (GnRH) analogues including leuprolide acetate and goserelin acetate implant. The hormone&rsquo;s activity can be stopped by androgens antagonist such as flutamide, bicalutamide and nilutamide along with chemotherapeutic agents, such as taxanes (e.g., docetaxel, paclitaxel) but after all the disease relapses in 20-30% of patients. So, new immunological or vaccine-based therapeutic moieties have been investigated to meet the objective of providing selectivity to cancerous cells and desired therapeutic outcomes with less/no harmful effects to normal cells. The chimeric version, oncolytic poliovirus and human rhinovirus i.e. PVSRIPO is most promising feature in cancer therapeutics and activate innate immunity by neutrophils infiltration via PAMP &amp; DAMP pathways while Sipuleucel-T expresses major histocompatibility complex (MHC) which can stimulate CD4+ helper T-cells and CD8+ cytotoxic T-cells and ultimately activate the acquired immunity against cancer cells. In this article, we have discussed the role of genetic predisposition and chemotherapeutic approaches including oncolytic poliovirus for the treatment of PaC in order to better understanding of tumor biology and mechanisms involved in chemotherapeutic drugs based resistance.

Gonadotrophin-releasing hormone receptors in GtoPdb v.2021.3

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].

Hypothalamic Hamartoma Revealed by Precocious Puberty in Girls: About A New Case

Precocious puberty is a multifactorial process whose diagnosis is based, first of all, on the clinic but also on the realization of the bone age, the pelvic ultrasound and the cerebral IRM. Moreover, the GnRH test constitutes the cornerstone to highlight a premature activation of the Hypothalamo-hypophyseal axis. We report the case of a 3-year-old girl admitted for exploration of precocious puberty. The central origin was confirmed by a GnRH test with a peak reaching 45 mIU/L. A hypothalamohypophyseal MRI was performed, showing a mass consistent with a hypothalamic hamartoma. Treatment with GnRH analogues is the treatment of choice for central precocious puberty.

Relugolix, an oral gonadotropin-releasing hormone antagonist for the treatment of prostate cancer

Androgen deprivation therapy using gonadotropin-releasing hormone (GnRH) analogues is standard treatment for intermediate and advanced prostate cancer. GnRH agonist therapy results in an initial testosterone flare, and increased metabolic and cardiovascular risks. The GnRH antagonist relugolix is able to reduce serum testosterone levels in men with prostate cancer without inducing testosterone flare. In the HERO Phase III trial, relugolix was superior to leuprolide acetate at rapidly reducing testosterone and continuously suppressing testosterone, with faster post-treatment recovery of testosterone levels. Relugolix was associated with a 54% lower incidence of major adverse cardiovascular events than leuprolide acetate. As the first oral GnRH antagonist approved for the treatment of advanced prostate cancer, relugolix offers a new treatment option.

Interplay Between mTOR and Hippo Signaling in the Ovary: Clinical Choice Guidance Between Different Gonadotropin Preparations for Better IVF

One of the most widely used types of assisted reproduction technology is the in vitro fertilization (IVF), in which women undergo controlled ovarian stimulation through the administration of the appropriate hormones to produce as many mature follicles, as possible. The most common hormone combination is the co-administration of gonadotropin-releasing hormone (GnRH) analogues with recombinant or urinary-derived follicle-stimulating hormone (FSH). In the last few years, scientists have begun to explore the effect that different gonadotropin preparations have on granulosa cells’ maturation and apoptosis, aiming to identify new predictive markers of oocyte quality and successful fertilization. Two major pathways that control the ovarian development, as well as the oocyte–granulosa cell communication and the follicular growth, are the PI3K/Akt/mTOR and the Hippo signaling. The purpose of this article is to briefly review the current knowledge about the effects that the different gonadotropins, used for ovulation induction, may exert in the biology of granulosa cells, focusing on the importance of these two pathways, which are crucial for follicular maturation. We believe that a better understanding of the influence that the various ovarian stimulation protocols have on these critical molecular cascades will be invaluable in choosing the best approach for a given patient, thereby avoiding cancelled cycles, reducing frustration and potential treatment-related complications, and increasing the pregnancy rate. Moreover, individualizing the treatment plan will help clinicians to better coordinate assisted reproductive technology (ART) programs, discuss the specific options with the couples undergoing IVF, and alleviate stress, thus making the IVF experience easier.