ABSTRACT
Our phase I graft-versus-host disease (GVHD) prevention trial of JAK2 inhibitor, pacritinib, (recommended phase II dose: 100mg po BID day 0 to +70) plus sirolimus and tacrolimus (PAC/SIR/TAC) demonstrated the regimen was safe and free of pan-JAK myelosuppression after allogeneic hematopoietic cell transplantation (alloHCT). PAC inhibits IL-6 receptor activity and pathogenic Th1/Th17 differentiation in preclinical models and the phase I trial. Herein we report on our completed phase II trial of PAC/SIR/TAC after 8/8-HLA matched alloHCT. This single-arm phase II trial (NCT02891603) was powered to determine if PAC/SIR/TAC suppressed %pSTAT3+ CD4+ T cells at day +21 (primary endpoint: %pSTAT3+ CD4+ T cells ≤ 35%) and estimated grade II-IV acute GVHD by day +100. The impact of PAC/SIR/TAC on T cell subsets, CD28 (pS6 and pH3ser10), and IL-2 receptor (pSTAT5) signal transduction was also evaluated. Eligible patients (n=28) received alloHCT for hematologic malignancies or myeloproliferative neoplasms. Reduced or myeloablative intensity conditioning was permitted. PAC/SIR/TAC met the primary endpoint, reducing %pSTAT3+ CD4+ T cells to 9.62% at day +21. Th1/Th17 cells were decreased at day +21, increasing the ratio of Tregs to Th1 and Th17 cells with PAC/SIR/TAC at RP2D PAC compared to dose level 1 PAC. The cumulative incidence of grade II-IV acute GVHD by day +100 with PAC/SIR/TAC was similar to historic SIR/TAC values (46 v 43%). While PAC/SIR/TAC suppressed pSTAT3 and Th1/Th17 cells, the regimen did not improve acute GVHD prevention.
ABSTRACT
BACKGROUND: Trilaciclib, in comparison to placebo plus carboplatin, etoposide, ± atezolizumab (PEA), has shown significant reductions in incidence of severe neutropenia (SN) among patients with extensive-stage small cell lung cancer (ES-SCLC). Despite these findings, real-world utility remains limited. METHODS: A single-center quasi-experimental study compared trilaciclib + PEA (PEAT) versus PEA in ES-SCLC patients. The study period ranged from April 1, 2021 to July 31, 2022, for the PEAT recipients and February 1, 2020, to February 28, 2021, for PEA recipients. The primary endpoint evaluated was incidence of SN after cycle 1 and during the treatment period. Secondary endpoints included measures related to myelopreservation and patient outcomes. RESULTS: Among 34 PEAT and 44 PEA patients, baseline characteristics were similar, except for a higher median age (69 vs 64 years) and more males (64.7% vs 38.6%) in the PEAT cohort. The PEAT cohort exhibited a lower SN rate (3%) versus the PEA cohort (18%), with statistical significance demonstrated on multivariate analysis (p = 0.015). Additionally, the PEAT cohort also demonstrated significant reductions in red blood cell transfusion requirements (3% vs 23%; p = 0.02), grade 3-4 anemia (6% vs 25%; p = 0.03), and grade 3-4 thrombocytopenia (0% vs 11%, p = 0.045). CONCLUSION: Trilaciclib, in combination with PEA, demonstrated an improvement in the safety profile without compromising survival outcomes in ES-SCLC patients. These findings underscore the potential benefits of incorporating trilaciclib in real-world clinical settings for enhanced patient care.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Lung Neoplasms , Small Cell Lung Carcinoma , Humans , Male , Female , Small Cell Lung Carcinoma/drug therapy , Small Cell Lung Carcinoma/pathology , Middle Aged , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Triazoles/administration & dosage , Triazoles/therapeutic use , Neutropenia/chemically induced , Neutropenia/epidemiology , Neoplasm Staging , Pyrimidines , PyrrolesABSTRACT
Patients with synchronous malignancies can be problematic to diagnose and manage because workup and therapeutic targeting for each individual malignancy must be coordinated carefully. This report presents a patient with concurrent chronic myeloid leukemia (CML) and chronic lymphocytic leukemia (CLL) managed with concomitant venetoclax and imatinib. Because imatinib is a moderate cytochrome P450 3A4 inhibitor, close monitoring is required when using with a substrate of 3A4 such as venetoclax. Although the target dose of venetoclax is 400 mg, it was capped at 100 mg due to the interaction. Despite the interaction and possible enhancement of toxicities, the patient has tolerated therapy well, and both diseases have responded to this novel approach. In addition, because aberrant BCL-2 activity has been implicated in CML, the use of venetoclax may contribute to success in the management of this patient's CML. This case report represents the safe concomitant use of venetoclax and imatinib in a patient with synchronous CML and CLL.
Subject(s)
Antineoplastic Agents , Leukemia, Lymphocytic, Chronic, B-Cell , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Humans , Imatinib Mesylate/therapeutic use , Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Antineoplastic Agents/therapeutic use , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapyABSTRACT
While consensus regarding the return of secondary genomic findings in the clinical setting has been reached, debate about such findings in the research setting remains. We developed a hybrid, research-clinical translational genomics process for research exome data coupled with a CLIA-validated secondary findings analysis. Eleven intramural investigators from ten institutes at the National Institutes of Health piloted this process. Nearly 1,200 individuals were sequenced and 14 secondary findings were identified in 18 participants. Positive secondary findings were returned by a genetic counselor following a standardized protocol, including referrals for specialty follow-up care for the secondary finding local to the participants. Interviews were undertaken with 13 participants 4 months after receipt of a positive report. These participants reported minimal psychologic distress within a process to assimilate their results. Of the 13, 9 reported accessing the recommended health care services. A sample of 107 participants who received a negative findings report were surveyed 4 months after receiving it. They demonstrated good understanding of the negative secondary findings result and most expressed reassurance (64%) from that report. However, a notable minority (up to 17%) expressed confusion regarding the distinction of primary from secondary findings. This pilot shows it is feasible to couple CLIA-compliant secondary findings to research sequencing with minimal harms. Participants managed the surprise of a secondary finding with most following recommended follow up, yet some with negative findings conflated secondary and primary findings. Additional work is needed to understand barriers to follow-up care and help participants distinguish secondary from primary findings.
Subject(s)
Exome/genetics , Female , Genetic Counseling/methods , Genomics/methods , Humans , Incidental Findings , Male , Middle Aged , Pilot ProjectsABSTRACT
Bones at different anatomical locations vary dramatically in size. For example, human femurs are 20-fold longer than the phalanges in the fingers and toes. The mechanisms responsible for these size differences are poorly understood. Bone elongation occurs at the growth plates and advances rapidly in early life but then progressively slows due to a developmental program termed "growth plate senescence." This developmental program includes declines in cell proliferation and hypertrophy, depletion of cells in all growth plate zones, and extensive underlying changes in the expression of growth-regulating genes. Here, we show evidence that these functional, structural, and molecular senescent changes occur earlier in the growth plates of smaller bones (metacarpals, phalanges) than in the growth plates of larger bones (femurs, tibias) and that this differential aging contributes to the disparities in bone length. We also show evidence that the molecular mechanisms that underlie the differential aging between different bones involve modulation of critical paracrine regulatory pathways, including insulin-like growth factor (Igf), bone morphogenetic protein (Bmp), and Wingless and Int-1 (Wnt) signaling. Taken together, the findings reveal that the striking disparities in the lengths of different bones, which characterize normal mammalian skeletal proportions, is achieved in part by modulating the progression of growth plate senescence.
Subject(s)
Aging/physiology , Bone and Bones/anatomy & histology , Cartilage/growth & development , Growth Plate/growth & development , Animals , Bone Development , Cell Proliferation , Chondrocytes/pathology , Extremities/growth & development , Gene Expression Regulation, Developmental , Hypertrophy , Mice, Inbred C57BL , Paracrine Communication , Rats, Sprague-Dawley , Tibia/growth & developmentABSTRACT
PURPOSE: Impaired function of gonadotropin-releasing hormone (GnRH) neurons can cause a phenotypic spectrum ranging from delayed puberty to isolated hypogonadotropic hypogonadism (IHH). We sought to identify a new genetic etiology for these conditions. METHODS: Exome sequencing was performed in an extended family with autosomal dominant, markedly delayed puberty. The effects of the variant were studied in a GnRH neuronal cell line. Variants in the same gene were sought in a large cohort of individuals with IHH. RESULTS: We identified a rare missense variant (F900V) in DLG2 (which encodes PSD-93) that cosegregated with the delayed puberty. The variant decreased GnRH expression in vitro. PSD-93 is an anchoring protein of NMDA receptors, a type of glutamate receptor that has been implicated in the control of puberty in laboratory animals. The F900V variant impaired the interaction between PSD-93 and a known binding partner, Fyn, which phosphorylates NMDA receptors. Variants in DLG2 that also decreased GnRH expression were identified in three unrelated families with IHH. CONCLUSION: The findings indicate that variants in DLG2/PSD-93 cause autosomal dominant delayed puberty and may also contribute to IHH. The findings also suggest that the pathogenesis involves impaired NMDA receptor signaling and consequently decreased GnRH secretion.
Subject(s)
Gonadotropin-Releasing Hormone , Hypogonadism , Gonadotropin-Releasing Hormone/genetics , Guanylate Kinases , Humans , Hypogonadism/genetics , Proteins , Signal Transduction , Tumor Suppressor Proteins , Exome SequencingABSTRACT
Immune checkpoints are cell surface molecules that initiate regulatory pathways which have powerful control of CD8+ cytolytic T cell activity. Antagonistic and agonistic antibodies engaging these molecules have demonstrated profound impact on immune activation and have entered clinical use for the treatment of a variety of diseases. Over the past decade, antagonistic antibodies known as immune checkpoint inhibitors have become a new pillar of cancer treatment and have reshaped the therapeutic landscape in oncology. These agents differ in their mechanism of action and toxicity profiles compared to more traditional systemic cancer treatments such as chemo- and targeted therapies. This article reviews the pharmacology of this new class of agents.
Subject(s)
Immunotherapy , Neoplasms , CTLA-4 Antigen , Humans , Immune Checkpoint Inhibitors , Neoplasms/drug therapy , Neoplasms/immunologyABSTRACT
Recombinant human growth hormone (GH) is commonly used to treat short stature in children. However, GH treatment has limited efficacy, particularly in severe, non-GH-deficient conditions such as chondrodysplasias, and potential off-target effects. Because short stature results from decreased growth plate chondrogenesis, we developed a cartilage-targeting single-chain human antibody fragment (CaAb) aiming to deliver therapeutic molecules to the growth plate, thereby increasing treatment efficacy while minimizing adverse effects on other tissues. To this end, we created fusion proteins of these CaAbs conjugated with insulin-like growth factor 1 (IGF-1), an endocrine and/or paracrine factor that positively regulates chondrogenesis. These CaAb-IGF-1 fusion proteins retained both cartilage binding and IGF-1 biological activity, and they were able to stimulate bone growth in an organ culture system. Using a GH-deficient (lit) mouse model, we found that subcutaneous injections of these CaAb-IGF-1 fusion proteins increased overall growth plate height without increasing proliferation in kidney cortical cells, suggesting on-target efficacy at the growth plate and less off-target effect on the kidney than IGF-1 alone. Alternate-day injections of these fusion proteins, unlike IGF-1 alone, were sufficient to produce a therapeutic effect. Our findings provide proof of principle that targeting therapeutics to growth plate cartilage can potentially improve treatment for childhood growth disorders.
Subject(s)
Insulin-Like Growth Factor I/pharmacology , Animals , Cartilage/drug effects , Cartilage/metabolism , Chondrogenesis/drug effects , Growth Plate/drug effects , Growth Plate/metabolism , Humans , MCF-7 Cells , Mice , Mice, Inbred C57BL , Mutation/geneticsABSTRACT
In many children with short stature, the etiology of the decreased linear growth remains unknown. We sought to identify the underlying genetic etiology in a patient with short stature, irregular growth plates of the proximal phalanges, developmental delay, and mildly dysmorphic facial features. Exome sequencing identified a de novo, heterozygous, nonsense mutation (c.1606C>T:p.R536X) in QRICH1. In vitro studies confirmed that the mutation impaired expression of the QRICH1 protein. SiRNA-mediated knockdown of Qrich1 in primary mouse epiphyseal chondrocytes caused downregulation of gene expression associated with hypertrophic differentiation. We then identified an unrelated individual with another heterozygous de novo nonsense mutation in QRICH1 who had a similar phenotype. A recently published study identified QRICH1 mutations in three patients with developmental delay, one of whom had short stature. Our findings indicate that QRICH1 mutations cause not only developmental delay but also a chondrodysplasia characterized by diminished linear growth and abnormal growth plate morphology due to impaired growth plate chondrocyte hypertrophic differentiation.
Subject(s)
Chondrogenesis/genetics , DNA-Binding Proteins/genetics , Developmental Disabilities/genetics , Microtubule Proteins/genetics , Osteochondrodysplasias/genetics , Transcription Factors/genetics , Animals , Child , Child, Preschool , Chondrocytes/metabolism , Chondrocytes/pathology , Codon, Nonsense/genetics , Developmental Disabilities/pathology , Exome/genetics , Female , Growth Plate/growth & development , Growth Plate/pathology , Heterozygote , Humans , Infant , Male , Mice , Mutation/genetics , Osteochondrodysplasias/pathologyABSTRACT
PURPOSE OF REVIEW: Genome-wide approaches including genome-wide association studies as well as exome and genome sequencing represent powerful new approaches that have improved our ability to identify genetic causes of human disorders. The purpose of this review is to describe recent advances in the genetic causes of short stature. RECENT FINDINGS: In addition to SHOX deficiency which is one of the most common causes of isolated short stature, PAPPA2, ACAN, NPPC, NPR2, PTPN11 (and other rasopathies), FBN1, IHH and BMP2 have been identified in isolated growth disorders with or without other mild skeletal findings. In addition, novel genetic causes of syndromic short stature have been discovered, including pathogenic variants in BRCA1, DONSON, AMMECR1, NFIX, SLC25A24, and FN1. SUMMARY: Isolated growth disorders are often monogenic. Specific genetic causes typically have specific biochemical and/or phenotype characteristics which are diagnostically helpful. Identification of additional subjects with a specific genetic cause of short stature often leads to a broadening of the known clinical spectrum for that condition. The identification of novel genetic causes of short stature has provided important insights into the underlying molecular mechanisms of growth failure.
Subject(s)
Dwarfism/diagnosis , Dwarfism/genetics , Growth Disorders/diagnosis , Growth Disorders/genetics , Child , Genetic Markers , Genetic Predisposition to Disease , Genetic Testing , Genome-Wide Association Study , Humans , Exome Sequencing , Whole Genome SequencingABSTRACT
Insulin-like growth factor 2 (IGF2) is an important fetal growth factor. Its expression is dramatically down-regulated in multiple organs after birth but is frequently up-regulated in cancers. The mechanisms that drive down-regulation of IGF2 in postnatal tissues or the up-regulation in malignancy are unclear. We found evidence that E2F transcription factor 3 (E2F3) drives these changes in expression. E2f3 mRNA expression, protein expression, and binding to the Igf2 promoter all decreased with age postnatally in multiple mouse organs. In late juvenile hepatocytes, restoration of high E2f3 expression restored high Igf2 expression, indicating a causal relationship, but this induction did not occur in fetal hepatocytes, which already have high E2f3 and Igf2 expression. Transient expression of E2f3 in both HEK293 cells and in late juvenile hepatocytes were able to activate reporter constructs containing the mouse Igf2 promoter P2, which includes consensus E2F-binding sites. In humans, microarray data revealed declines in E2F3 and IGF2 expression with age similar to the mouse. In addition, E2F3-overexpressing human prostate and bladder cancers showed increased IGF2 expression, and levels of E2F3 and IGF2 mRNA in these cancers were positively correlated. Taken together, the findings suggest that down-regulation of E2f3 with age helps drive the dramatic decline in Igf2 expression in postnatal organs, and E2F3 overexpression in human cancers induces IGF2 overexpression.
Subject(s)
E2F3 Transcription Factor/metabolism , Gene Expression Regulation, Developmental , Gene Expression Regulation, Neoplastic , Insulin-Like Growth Factor II/metabolism , Animals , Cell Line, Tumor , Cell Proliferation , Computational Biology , Down-Regulation , E2F3 Transcription Factor/genetics , Hepatocytes/cytology , Humans , Insulin-Like Growth Factor II/genetics , Mice , Mice, Inbred C57BL , Oligonucleotide Array Sequence Analysis , Promoter Regions, Genetic , Time FactorsABSTRACT
CONTEXT: The primary preoperative method for distinguishing malignant from benign thyroid nodules is fine-needle aspiration (FNA) cytology, but it is frequently inconclusive. Midkine (MDK) is a heparin-binding growth factor, which is overexpressed in papillary thyroid carcinoma (PTC). OBJECTIVE: We measured MDK concentrations in FNA samples from benign and malignant thyroid nodules to explore the possibility that MDK measurement might aid in the evaluation of thyroid nodules. DESIGN: 35 subjects underwent preoperative FNA of 45 thyroid nodules, followed by thyroidectomy, providing a histological diagnosis. FNA needle contents were first expressed for cytology, and then, the needle was washed with buffer for immunoassay. In 46 subjects without preoperative FNA samples, FNA was performed ex vivo on 62 nodules within surgically excised thyroid tissue. MEASUREMENTS: MDK was measured using a high-sensitivity sandwich ELISA and normalized to thyroglobulin (Tg) concentration in the sample to adjust for tissue content in the aspirate. RESULTS: The MDK/Tg ratio was higher in 18 PTCs than in 87 benign nodules (204 ± 106 vs 1·2 ± 0·3 ng/mg, mean ± SEM, P < 0·001). Using a threshold of 10 ng/mg, the sensitivity and specificity of the MDK/Tg ratio for diagnosis of PTC were 67% and 99%, respectively. All follicular variant PTCs had a MDK/Tg ratio <10 ng/mg. CONCLUSIONS: The findings indicate that, in FNA samples, the MDK/Tg ratio in PTC is greater than in benign thyroid nodules, raising the possibility that this approach might provide adjunctive diagnostic or prognostic information to complement existing approaches.
Subject(s)
Biopsy, Fine-Needle/methods , Cytokines/analysis , Thyroglobulin/analysis , Thyroid Nodule/chemistry , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , MidkineABSTRACT
BACKGROUND: In juvenile mammals, the epiphyses of long bones grow by chondrogenesis within the articular cartilage. A better understanding of the molecular mechanisms that regulate the growth of articular cartilage may give insight into the antecedents of joint disease, such as osteoarthritis. METHODS: We used laser capture microdissection to isolate chondrocytes from the superficial, middle, and deep zones of growing tibial articular cartilage in the 1-wk-old mouse and then investigated expression patterns by microarray. To identify molecular markers for each zone of the growing articular cartilage, we found genes showing zone-specific expression and confirmed by real-time PCR and in situ hybridization. RESULTS: Bioinformatic analyses implicated ephrin receptor signaling, Wnt signaling, and bone morphogenetic protein signaling in the spatial regulation of chondrocyte differentiation during growth. Molecular markers were identified for superficial (e.g., Cilp, Prg4), middle (Cxcl14, Tnn), and deep zones (Sfrp5, Frzb). Comparison between juvenile articular and growth plate cartilage revealed that the superficial-to-deep zone transition showed similarity with the hypertrophic-to-resting zone transition. CONCLUSION: Laser capture microdissection combined with microarray analysis identified novel signaling pathways that are spatially regulated in growing mouse articular cartilage and revealed similarities between the molecular architecture of the growing articular cartilage and that of growth plate cartilage.
Subject(s)
Cartilage, Articular/growth & development , Chondrogenesis/physiology , Gene Expression Regulation, Developmental/physiology , Signal Transduction/physiology , Animals , Bone Morphogenetic Proteins/metabolism , Cartilage, Articular/metabolism , Cell Differentiation/physiology , Computational Biology , Gene Expression Profiling , In Situ Hybridization , Laser Capture Microdissection , Mice , Microarray Analysis , Real-Time Polymerase Chain Reaction , Receptors, Eph Family/metabolism , Wnt Proteins/metabolismABSTRACT
PURPOSE: Many genetic disorders, including chondrodysplasias, and acquired disorders impair growth plate function, resulting in short and sometimes malformed bones. There are multiple endocrine and paracrine factors that promote chondrogenesis at the growth plate, which could potentially be used to treat these disorders. Targeting these growth factors specifically to the growth plate might augment the therapeutic skeletal effect while diminishing undesirable effects on non-target tissues. METHODS: Using yeast display technology, we selected single-chain variable antibody fragments that bound to human and mouse matrilin-3, an extracellular matrix protein specifically expressed in cartilage tissue. The ability of the selected antibody fragments to bind matrilin-3 and to bind cartilage tissue in vitro and in vivo was assessed by ELISA and immunohistochemistry. RESULTS: We identified antibody fragments that bound matrilin-3 with high affinity and also bound with high tissue specificity to cartilage homogenates and to cartilage structures in mouse embryo sections. When injected intravenously in mice, the antibody fragments specifically homed to cartilage. CONCLUSIONS: Yeast display successfully selected antibody fragments that are able to target cartilage tissue in vivo. Coupling these antibodies to chondrogenic endocrine and paracrine signaling molecules has the potential to open up new pharmacological approaches to treat childhood skeletal growth disorders.
Subject(s)
Growth Plate/drug effects , Immunoglobulin Fragments/pharmacology , Matrilin Proteins/metabolism , Single-Chain Antibodies/pharmacology , Animals , Antibody Specificity , Cloning, Molecular , Growth Plate/embryology , Growth Plate/metabolism , HEK293 Cells , Humans , Immunoglobulin Fragments/administration & dosage , Immunoglobulin Fragments/toxicity , Immunohistochemistry , Matrilin Proteins/genetics , Mice , Mice, Inbred C57BL , Protein Binding , Recombinant Proteins/metabolism , Single-Chain Antibodies/administration & dosage , Single-Chain Antibodies/toxicity , Yeasts/geneticsABSTRACT
PURPOSE OF REVIEW: Recent basic studies have yielded important new insights into the molecular mechanisms that regulate growth locally. Simultaneously, clinical studies have identified new molecular defects that cause growth failure and overgrowth, and genome-wide association studies have elucidated the genetic basis for normal human height variation. RECENT FINDINGS: The Hippo pathway has emerged as one of the major mechanisms controlling organ size. In addition, an extensive genetic program has been described that allows rapid body growth in the fetus and infant but then causes growth to slow with age in multiple tissues. In human genome-wide association studies, hundreds of loci associated with adult stature have been identified; many appear to involve genes that function locally in the growth plate. Clinical genetic studies have identified a new genetic abnormality, microduplication of Xq26.3, that is responsible for growth hormone excess, and a gene, DNMT3A, in which mutations cause an overgrowth syndrome through epigenetic mechanisms. SUMMARY: These recent advances in our understanding of somatic growth not only provide insight into childhood growth disorders but also have broader medical applications because disruption of these regulatory systems contributes to oncogenesis.
Subject(s)
Body Height/genetics , Genome-Wide Association Study , Growth Disorders/genetics , Growth Plate/metabolism , Hippocampus/physiology , Body Height/physiology , Child , Child Nutritional Physiological Phenomena , Child, Preschool , Gene Expression Profiling , Growth Disorders/physiopathology , Growth Plate/physiology , Humans , Infant , Infant, Newborn , Mutation , Phenotype , Quantitative Trait Loci/genetics , Signal TransductionABSTRACT
Previous meta-analysis of genome-wide association (GWA) studies has identified 180 loci that influence adult height. However, each GWA locus typically comprises a set of contiguous genes, only one of which presumably modulates height. We reasoned that many of the causative genes within these loci influence height because they are expressed in and function in the growth plate, a cartilaginous structure that causes bone elongation and thus determines stature. Therefore, we used expression microarray studies of mouse and rat growth plate, human disease databases and a mouse knockout phenotype database to identify genes within the GWAS loci that are likely required for normal growth plate function. Each of these approaches identified significantly more genes within the GWA height loci than at random genomic locations (P < 0.0001 each), supporting the validity of the approach. The combined analysis strongly implicates 78 genes in growth plate function, including multiple genes that participate in PTHrP-IHH, BMP and CNP signaling, and many genes that have not previously been implicated in the growth plate. Thus, this analysis reveals a large number of novel genes that regulate human growth plate chondrogenesis and thereby contribute to the normal variations in human adult height. The analytic approach developed for this study may be applied to GWA studies for other common polygenic traits and diseases, thus providing a new general strategy to identify causative genes within GWA loci and to translate genetic associations into mechanistic biological insights.
Subject(s)
Body Height/genetics , Gene Expression Profiling , Genome-Wide Association Study , Growth Plate/metabolism , Animals , Computational Biology/methods , Genomics , Growth Plate/growth & development , Humans , Male , Mice , Phenotype , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Reproducibility of ResultsABSTRACT
Human overgrowth disorders are characterized by excessive prenatal and/or postnatal growth of various tissues. These disorders often present with tall stature, macrocephaly, and/or abdominal organomegaly and are sometimes associated with additional phenotypic abnormalities such as intellectual disability and increased cancer risk. As the genetic etiology of these disorders have been elucidated, a surprising pattern has emerged. Multiple monogenic overgrowth syndromes result from variants in epigenetic regulators: variants in histone methyltransferases NSD1 and EZH2 cause Sotos syndrome and Weaver syndrome, respectively, variants in DNA methyltransferase DNMT3A cause Tatton-Brown-Rahman syndrome, and variants in chromatin remodeler CHD8 cause an autism spectrum disorder with overgrowth. In addition, very recently, a variant in histone reader protein SPIN4 was identified in a new X-linked overgrowth disorder. In this review, we discuss the genetics of these overgrowth disorders and explore possible common underlying mechanisms by which epigenetic pathways regulate human body size.
Subject(s)
Abnormalities, Multiple , Autism Spectrum Disorder , Intellectual Disability , Humans , Abnormalities, Multiple/genetics , Syndrome , Histone Methyltransferases/genetics , Intellectual Disability/genetics , Epigenesis, GeneticABSTRACT
Background: The expanding roles and popularity of glucagon-like peptide-1 (GLP-1) and GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor agonists has created access barriers to medication use. We sought to describe an adverse drug event which occurred after reinitiation of a GLP-1 receptor agonist following a prolonged lapse in therapy due to poor medication access. Case Summary: Once-weekly injectable semaglutide was prescribed to an outpatient 33-year-old male for chronic weight management. After a delayed initiation due to global shortage, semaglutide was initiated and titrated over five months before a seven week lapse in therapy due to prior authorization interruption. Despite the extended treatment gap, the patient was directed to reinitiate semaglutide at the target dose rather than starting dose, which was followed by recurrent, symptomatic nausea and vomiting requiring medical intervention. Practice Implications: A prolonged lapse in GLP-1 receptor agonist therapy, typically defined as missing three or more doses of a once-weekly injectable, warrants consideration of reinitiation at a reduced dose, personalized to the patient's prior gastrointestinal tolerability, efficacy goals, and therapy lapse duration. Therapy lapses with GLP-1 receptor agonists may be prevented by utilizing a multi-modal approach including extended dosing intervals, intermediate doses, agent interchange, efficient prior authorization communication, and cautious initiation of GLP-1 recent agonists while supply cannot meet demand.
ABSTRACT
Overgrowth syndromes can be caused by pathogenic genetic variants in epigenetic writers, such as DNA and histone methyltransferases. However, no overgrowth disorder has previously been ascribed to variants in a gene that acts primarily as an epigenetic reader. Here, we studied a male individual with generalized overgrowth of prenatal onset. Exome sequencing identified a hemizygous frameshift variant in Spindlin 4 (SPIN4), with X-linked inheritance. We found evidence that SPIN4 binds specific histone modifications, promotes canonical WNT signaling, and inhibits cell proliferation in vitro and that the identified frameshift variant had lost all of these functions. Ablation of Spin4 in mice recapitulated the human phenotype with generalized overgrowth, including increased longitudinal bone growth. Growth plate analysis revealed increased cell proliferation in the proliferative zone and an increased number of progenitor chondrocytes in the resting zone. We also found evidence of decreased canonical Wnt signaling in growth plate chondrocytes, providing a potential explanation for the increased number of resting zone chondrocytes. Taken together, our findings provide strong evidence that SPIN4 is an epigenetic reader that negatively regulates mammalian body growth and that loss of SPIN4 causes an overgrowth syndrome in humans, expanding our knowledge of the epigenetic regulation of human growth.