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Frontiers in Endocrinology 2023Linear growth during childhood is the result of the synergic contribution of different factors. The best growth determinant system during each period of life is... (Review)
Review
Linear growth during childhood is the result of the synergic contribution of different factors. The best growth determinant system during each period of life is represented by the growth hormone-insulin-like growth factor axis (GH-IGF), even if several other factors are involved in normal growth. Within the broad spectrum of growth disorders, an increased importance has been placed on growth hormone insensitivity (GHI). GHI was reported for the first time by Laron as a syndrome characterized by short stature due to GH receptor (GHR) mutation. To date, it is recognized that GHI represents a wide diagnostic category, including a broad spectrum of defects. The peculiar characteristic of GHI is the low IGF-1 levels associated with normal or elevated GH levels and the lack of IGF-1 response after GH administration. Recombinant IGF-1 preparations may be used in the treatment of these patients.
Topics: Dwarfism; Human Growth Hormone; Insulin-Like Growth Factor I; Humans; Growth Disorders
PubMed: 37008935
DOI: 10.3389/fendo.2023.1141039 -
Gene Therapy Jun 2022
Topics: Genetic Therapy; Humans; Insulin-Like Growth Factor I; Laron Syndrome; Mutation
PubMed: 35283485
DOI: 10.1038/s41434-022-00329-2 -
Molecular and Cellular Endocrinology Dec 2020Emerging evidence links the growth hormone (GH)-insulin-like growth factor-1 (IGF1) endocrine axis to cancer development. While this putative correlation is of major... (Review)
Review
Emerging evidence links the growth hormone (GH)-insulin-like growth factor-1 (IGF1) endocrine axis to cancer development. While this putative correlation is of major translational relevance, most clinical and epidemiological reports to date found no causal linkage between GH therapy and enhanced cancer risk. Thus, it is generally agreed that GH therapy constitutes a safe pharmacological intervention. The present review focuses on a number of issues in the area of GH-IGF1 action in cancer development. Emphasis is given to the idea that GH and IGF1 do not conform to the definition of oncogenic factors. Specifically, these hormones, even at high pharmacological doses, are unable to induce malignant transformation. However, the GH-IGF1 axis is capable of 'pushing' already transformed cells through the various phases of the cell cycle. Viral and cellular oncogenes require an intact IGF1 signaling pathway in order to elicit transformation; in other words, oncogenic agents adopt the IGF1 pathway. This universal mechanism of action of oncogenes has broad implications in oncology. Our review provides an in-depth analysis of the interplay between the GH-IGF1 axis and cancer genes, including tumor suppressors p53 and BRCA1. Finally, the safety of GH therapy in both children and adults needs further long-term follow-up studies.
Topics: Adult; Cell Cycle; Child; Disease Progression; Human Growth Hormone; Humans; Insulin-Like Growth Factor I; Neoplasms; Oncogenes; Signal Transduction
PubMed: 32919021
DOI: 10.1016/j.mce.2020.111003 -
Endocrine-related Cancer May 2023Interest in investigating the role of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis in the initiation and progression of experimentally induced... (Review)
Review
Interest in investigating the role of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis in the initiation and progression of experimentally induced carcinomas has arisen due to several observations in the human population. First, subjects with Laron syndrome who lack GH signaling have significantly lower rates of cancer than people who have normal GH signaling. Second, epidemiologic studies have found strong associations between elevated circulating IGF-1 and the incidence of several common cancers. Third, women who bear children early in life have a dramatically reduced risk of developing breast cancer, which may be due to differences in hormone levels including GH. These observations have motivated multiple studies that have experimentally altered activity of the GH/IGF-1 axis in the context of experimental carcinoma models in mice and rats. Most of these studies have utilized carcinoma models for four organ systems that are also frequent sites of carcinomas in humans: the mammary gland, prostate gland, liver, and colon. This review focuses on these studies and describes some of the most common genetic models used to alter the activity of the GH/IGF-1 axis in experimentally induced carcinomas. A recurring theme that emerges from these studies is that manipulations that reduce the activity of GH or mediators of GH action also inhibit carcinogenesis in multiple model systems.
Topics: Male; Female; Rats; Mice; Humans; Animals; Growth Hormone; Insulin-Like Growth Factor I; Neoplasm Recurrence, Local; Human Growth Hormone; Carcinoma
PubMed: 36826838
DOI: 10.1530/ERC-22-0403 -
Endocrine-related Cancer Oct 2023The relationship between growth hormone (GH) excess and cancer is a controversial matter. Until 2016, most studies in patients with acromegaly found links with colon and... (Review)
Review
The relationship between growth hormone (GH) excess and cancer is a controversial matter. Until 2016, most studies in patients with acromegaly found links with colon and thyroid neoplasms. However, recent studies found increased risks in gastric, breast, and urinary tract cancer also. Concordantly, clinical situations where GH and insulin-like growth facto-I deficits exist are indeed associated with diminished malignancy incidence. In line with these observations, gain-of-function mutations of various enzymes belonging to the GH and IGF-I signaling pathways have been associated with increased carcinogenesis; similarly, loss-of-function mutations of other enzymes that usually work as tumor repressors are also associated with augmented cancer risk. In a study performed in Ecuador, it was demonstrated that subjects in the Ecuadorian cohort with Laron syndrome (ELS), who have a mutant GH receptor and greatly diminished GH and IGF-I signaling, display diminished incidence of cancer. Along with absent action of GH and IGF-I, ELS individuals also have low serum insulin levels and decreased insulin resistance. Furthermore, hyperglycemia and hyperinsulinemia are indispensable for fast cell mitosis, including that of those cells present in the benign and malignant neoplasms. Notably, and despite their obesity, subjects with the ELS display normoglycemia and hypo-insulinemia, along with diminished incidence of malignancies. We believe that the dual low-IGF-I/low insulin serum levels are responsible for the cancer protection, especially considering that the insulin/INSR signaling is a central site for energy generation in the form of ATP and GDP, which are indispensable for all and every GH/IGF-I physiologic as well as pathologic events.
Topics: Humans; Growth Hormone; Acromegaly; Insulin-Like Growth Factor I; Human Growth Hormone; Insulin; Neoplasms
PubMed: 37428642
DOI: 10.1530/ERC-22-0402 -
Cells Nov 2020Laron syndrome (LS) is a rare genetic endocrinopathy that results from mutation of the growth hormone receptor () gene and is typically associated with dwarfism and... (Review)
Review
Laron syndrome (LS) is a rare genetic endocrinopathy that results from mutation of the growth hormone receptor () gene and is typically associated with dwarfism and obesity. LS is the best characterized entity under the spectrum of the congenital insulin-like growth factor-1 (IGF1) deficiencies. Epidemiological analyses have shown that LS patients do not develop cancer, whereas heterozygous family members have a cancer prevalence similar to the general population. To identify genes and signaling pathways differentially represented in LS that may help delineate a biochemical and molecular basis for cancer protection, we have recently conducted a genome-wide profiling of LS patients. Studies were based on our collection of Epstein-Barr virus (EBV)-immortalized lymphoblastoid cell lines derived from LS patients, relatives and healthy controls. Bioinformatic analyses identified differences in gene expression in several pathways, including apoptosis, metabolic control, cytokine biology, Jak-STAT and PI3K-AKT signaling, etc. Genes involved in the control of cell cycle, motility, growth and oncogenic transformation are, in general, down-regulated in LS. These genetic events seem to have a major impact on the biological properties of LS cells, including proliferation, apoptosis, response to oxidative stress, etc. Furthermore, genomic analyses allowed us to identify novel IGF1 downstream target genes that have not been previously linked to the IGF1 signaling pathway. In summary, by '' genomic data from LS patients, we were able to generate clinically-relevant information in oncology and, potentially, related disciplines.
Topics: Animals; Biomedical Research; Humans; Insulin-Like Growth Factor I; Intercellular Signaling Peptides and Proteins; Laron Syndrome; Neoplasms; Risk Factors
PubMed: 33182502
DOI: 10.3390/cells9112446 -
Seminars in Cell & Developmental Biology Jan 2022Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune... (Review)
Review
Sertoli cells (SCs) are immune privileged cells found in the testis that function to immunologically protect maturing germ cells from immune destruction. This immune protection is due to the blood-testis-barrier, which prevents infiltration of cytotoxic immune cells and antibodies, and SC production of immunomodulatory factors, that favor a tolerogenic environment. The ability of SCs to create an immune privileged environment has led to the exploration of their potential use in the treatment of various diseases. SCs have been utilized to create a tolerogenic ectopic microenvironment, to protect co-grafted cells, and to deliver therapeutic proteins through gene therapy. To date, numerous studies have reported the potential use of SCs for the treatment of diabetes, neurodegenerative disorders, and restoration of spermatogenesis. Additionally, SCs have been investigated as a delivery vehicle for therapeutic products to treat other diseases like Laron syndrome, muscular dystrophy, and infections. This review will provide an overview of these therapeutic applications.
Topics: Animals; Cell- and Tissue-Based Therapy; Humans; Male; Mice; Sertoli Cells
PubMed: 33910764
DOI: 10.1016/j.semcdb.2021.04.007 -
Orphanet Journal of Rare Diseases Oct 2023Severe primary insulin-like growth factor-I (IGF-I) deficiency (SPIGFD) is a rare growth disorder characterized by short stature (standard deviation score... (Review)
Review
BACKGROUND
Severe primary insulin-like growth factor-I (IGF-I) deficiency (SPIGFD) is a rare growth disorder characterized by short stature (standard deviation score [SDS] ≤ 3.0), low circulating concentrations of IGF-I (SDS ≤ 3.0), and normal or elevated concentrations of growth hormone (GH). Laron syndrome is the best characterized form of SPIGFD, caused by a defect in the GH receptor (GHR) gene. However, awareness of SPIGFD remains low, and individuals living with SPIGFD continue to face challenges associated with diagnosis, treatment and care.
OBJECTIVE
To gather perspectives on the key challenges for individuals and families living with SPIGFD through a multi-stakeholder approach. By highlighting critical gaps in the awareness, diagnosis, and management of SPIGFD, this report aims to provide recommendations to improve care for people affected by SPIGFD globally.
METHODS
An international group of clinical experts, researchers, and patient and caregiver representatives from the SPIGFD community participated in a virtual, half-day meeting to discuss key unmet needs and opportunities to improve the care of people living with SPIGFD.
RESULTS
As a rare disorder, limited awareness and understanding of SPIGFD amongst healthcare professionals (HCPs) poses significant challenges in the diagnosis and treatment of those affected. Patients often face difficulties associated with receiving a formal diagnosis, delayed treatment initiation and limited access to appropriate therapy. This has a considerable impact on the physical health and quality of life for patients, highlighting a need for more education and clearer guidance for HCPs. Support from patient advocacy groups is valuable in helping patients and their families to find appropriate care. However, there remains a need to better understand the burden that SPIGFD has on individuals beyond height, including the impact on physical, emotional, and social wellbeing.
CONCLUSIONS
To address the challenges faced by individuals and families affected by SPIGFD, greater awareness of SPIGFD is needed within the healthcare community, and a consensus on best practice in the care of individuals affected by this condition. Continued efforts are also needed at a global level to challenge existing perceptions around SPIGFD, and identify solutions that promote equitable access to appropriate care. Medical writing support was industry-sponsored.
Topics: Humans; Insulin-Like Growth Factor I; Quality of Life; Laron Syndrome; Dwarfism; Growth Disorders
PubMed: 37805563
DOI: 10.1186/s13023-023-02928-7 -
Reviews in Endocrine & Metabolic... Mar 2021The Ecuadorian cohort of subjects with LS has taught us valuable lessons since the late 80's. We have learned about migration of Sephardic Jews to our country, their... (Review)
Review
The Ecuadorian cohort of subjects with LS has taught us valuable lessons since the late 80's. We have learned about migration of Sephardic Jews to our country, their isolation in remote hamlets and further inbreeding. These geographical, historical and social determinants induced dissemination of a growth hormone (GH) receptor mutation which widely occurred in those almost inaccessible villages. Consequently, the world's largest Laron syndrome (LS) cohort emerged in Loja and El Oro, two of the southern provinces of Ecuador. We have been fortunate to study these patients since 1987. New clinical features derived from GH insensitivity, their growth patterns as well as treatment with exogenous insulin-like growth factor I (IGF-I) have been reported. Novel biochemical characteristics in the field of GH insensitivity, IGFs, IGF binding proteins (BP) and their clinical correlates have also been described. In the last few years, studies on the morbidity and mortality of Ecuadorian LS adults surprisingly demonstrated that despite obesity, they had lower incidence of diabetes and cancer than their relatives. These events were linked to their metabolic phenotype of elevated but ineffective GH concentrations and low circulating IGF-I and IGFBP-3. It was also noted that absent GH counter-regulation induces a decrease in insulin resistance (IR), which results in low but highly efficient insulin levels which properly handle metabolic substrates. We propose that the combination of low IGF-I signaling, decreased IR, and efficient serum insulin concentrations are reasonable explanations for the diminished incidence of diabetes and cancer in these subjects.
Topics: Ecuador; Humans; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I; Laron Syndrome; Phenotype; Receptors, Somatotropin
PubMed: 33047268
DOI: 10.1007/s11154-020-09602-4 -
Reviews in Endocrine & Metabolic... Mar 2021Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in... (Review)
Review
Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in severe post-natal growth failure as consequences of insulin-like growth factor I (IGF-I) deficiency. Over the years, recognition of other monogenic defects downstream of GHR has greatly expanded understanding of primary causes of GHI and growth retardation, with either IGF-I deficiency or IGF-I insensitivity as clinical outcomes. Mutations in IGF1 and signaling component STAT5B disrupt IGF-I production, while defects in IGFALS and PAPPA2, disrupt transport and release of circulating IGF-I, respectively, affecting bioavailability of the growth-promoting IGF-I. Defects in IGF1R, cognate cell-surface receptor for IGF-I, disrupt not only IGF-I actions, but actions of the related IGF-II peptides. The importance of IGF-II for normal developmental growth is emphasized with recent identification of defects in the maternally imprinted IGF2 gene. Current application of next-generation genomic sequencing has expedited the pace of identifying new molecular defects in known genes or in new genes, thereby expanding the spectrum of GH and IGF insensitivity. This review discusses insights gained and future directions from patient-based molecular and functional studies.
Topics: Abnormalities, Multiple; Growth Disorders; Growth Hormone; Human Growth Hormone; Humans; Insulin-Like Growth Factor I; Laron Syndrome; Mutation
PubMed: 33029712
DOI: 10.1007/s11154-020-09603-3