Epigenetic insights to pediatric uropathology: Celebrating the fundamental biology vision of Tony Khoury.

Introduction: Many pediatric urology conditions affect putatively normal tissues or appear too commonly to be based solely on specific DNA mutations. Understanding epigenetic mechanisms in pediatric urology, therefore, has many implications that can impact cell and tissue responses to settings, such as environmental and hormonal influences on urethral development, uropathogenic infections, obstructive stimuli, all of which originate externally or extracellularly. Indeed, the cell's response to external stimuli is often mediated epigenetically.

CD44 and RHAMM Are Microenvironmental Sensors with Dual Metastasis Promoter and Suppressor Functions.

The progression of primary tumors to metastases remains a significant roadblock to the treatment of most cancers. Emerging evidence has identified genes that specifically affect metastasis and are potential therapeutic targets for managing tumor progression. However, these genes can have dual tumor promoter and suppressor functions that are contextual in manifestation, and that complicate their development as targeted therapies.

RHAMM regulates MMTV-PyMT-induced lung metastasis by connecting STING-dependent DNA damage sensing to interferon/STAT1 pro-apoptosis signaling.

Background: RHAMM is a multifunctional protein that is upregulated in breast tumors, and the presence of strongly RHAMM cancer cell subsets associates with elevated risk of peripheral metastasis. Experimentally, RHAMM impacts cell cycle progression and cell migration. However, the RHAMM functions that contribute to breast cancer metastasis are poorly understood.

Receptor for hyaluronan-mediated motility (RHAMM) defines an invasive niche associated with tumor progression and predicts poor outcomes in breast cancer patients.

Breast cancer invasion and metastasis result from a complex interplay between tumor cells and the tumor microenvironment (TME). Key oncogenic changes in the TME include aberrant synthesis, processing, and signaling of hyaluronan (HA). Hyaluronan-mediated motility receptor (RHAMM, CD168; HMMR) is an HA receptor enabling tumor cells to sense and respond to this aberrant TME during breast cancer progression.

Nutritional status at age 1 year in patients born with esophageal atresia: A population-based, prospective cohort study.

Objective: Despite recent progress in caring for patients born with esophageal atresia (EA), undernutrition and stunting remain common. Our study objective was to assess nutritional status in the first year after birth with EA and to identify factors associated with growth failure.

Study Design: We conducted a population-based study of all infants born in France with EA between 2010 and 2016.

Hyaluronan Functions in Wound Repair That Are Captured to Fuel Breast Cancer Progression.

Signaling from an actively remodeling extracellular matrix (ECM) has emerged as a critical factor in regulating both the repair of tissue injuries and the progression of diseases such as metastatic cancer. Hyaluronan (HA) is a major component of the ECM that normally functions in tissue injury to sequentially promote then suppress inflammation and fibrosis, a duality in which is featured, and regulated in, wound repair. These essential response-to-injury functions of HA in the microenvironment are hijacked by tumor cells for invasion and avoidance of immune detection.

RHAMM Is a Multifunctional Protein That Regulates Cancer Progression.

The functional complexity of higher organisms is not easily accounted for by the size of their genomes. Rather, complexity appears to be generated by transcriptional, translational, and post-translational mechanisms and tissue organization that produces a context-dependent response of cells to specific stimuli. One property of gene products that likely increases the ability of cells to respond to stimuli with complexity is the multifunctionality of expressed proteins.

Esophageal Atresia and Respiratory Morbidity.

Background And Objectives: Respiratory diseases are common in children with esophageal atresia (EA), leading to increased morbidity and mortality in the first year. The primary study objective was to identify the factors associated with readmissions for respiratory causes in the first year in EA children.

Methods: A population-based study.

Risk Factors of Early Mortality and Morbidity in Esophageal Atresia with Distal Tracheoesophageal Fistula: A Population-Based Cohort Study.

Objective: To identify the risk factors for early mortality and morbidity in a population with distal esophageal atresia (EA)-tracheoesophageal fistula.

Study Design: Cohort study from a national register. Main outcomes and measures included early mortality, hospital length of stay (LoS), need for nutritional support at 1 year of age as a proxy measure of morbidity, and complications during the first year of life.

Cell-specific expression of the transcriptional regulator RHAMM provides a timing mechanism that controls appropriate wound re-epithelialization.

Prevention of aberrant cutaneous wound repair and appropriate regeneration of an intact and functional integument require the coordinated timing of fibroblast and keratinocyte migration. Here, we identified a mechanism whereby opposing cell-specific motogenic functions of a multifunctional intracellular and extracellular protein, the receptor for hyaluronan-mediated motility (RHAMM), coordinates fibroblast and keratinocyte migration speed and ensures appropriate timing of excisional wound closure. We found that, unlike in WT mice, in -null mice, keratinocyte migration initiates prematurely in the excisional wounds, resulting in wounds that have re-surfaced before the formation of normal granulation tissue, leading to a defective epidermal architecture.

Creating a Favorable Microenvironment for Fat Grafting in a Novel Model of Radiation-Induced Mammary Fat Pad Fibrosis.

Background: Radiofibrosis of breast tissue compromises breast reconstruction by interfering with tissue viability and healing. Autologous fat transfer may reduce radiotherapy-related tissue injury, but graft survival is compromised by the fibrotic microenvironment. Elevated expression of receptor for hyaluronan-mediated motility (RHAMM; also known as hyaluronan-mediated motility receptor, or HMMR) in wounds decreases adipogenesis and increases fibrosis.

Dissecting the Dual Nature of Hyaluronan in the Tumor Microenvironment.

Hyaluronan (HA) is a glycosaminoglycan with a simple structure but diverse and often opposing functions. The biological activities of this polysaccharide depend on its molecular weight and the identity of interacting receptors. HA is initially synthesized as high molecular-weight (HMW) polymers, which maintain homeostasis and restrain cell proliferation and migration in normal tissues.

Spatial statistical tools for genome-wide mutation cluster detection under a microarray probe sampling system.

Mutation cluster analysis is critical for understanding certain mutational mechanisms relevant to genetic disease, diversity, and evolution. Yet, whole genome sequencing for detection of mutation clusters is prohibitive with high cost for most organisms and population surveys. Single nucleotide polymorphism (SNP) genotyping arrays, like the Mouse Diversity Genotyping Array, offer an alternative low-cost, screening for mutations at hundreds of thousands of loci across the genome using experimental designs that permit capture of de novo mutations in any tissue.

A truncated RHAMM protein for discovering novel therapeutic peptides.

The receptor for hyaluronan mediated motility (RHAMM, gene name HMMR) belongs to a group of proteins that bind to hyaluronan (HA), a high-molecular weight anionic polysaccharide that has pro-angiogenic and inflammatory properties when fragmented. We propose to use a chemically synthesized, truncated version of the protein (706-767), 7 kDa RHAMM, as a target receptor in the screening of novel peptide-based therapeutic agents. Chemical synthesis by Fmoc-based solid-phase peptide synthesis, and optimization using pseudoprolines, results in RHAMM protein of higher purity and yield than synthesis by recombinant protein production.

Mouse Mammary Gland Whole Mount Preparation and Analysis.

The mammary gland undergoes extensive remodeling during pregnancy and is also subject to neoplastic processes both of which result in histological changes of the gland epithelial structure. Since the mammary tree is a complex three-dimensional structure a method is needed that provides an overview of the entire gland. Whole mounts provide this information, are inexpensive and do not require specialized equipment.

Hyaluronan Isolation from Mouse Mammary Gland.

The glycosaminoglycan hyaluronan (HA) is a key component of the extracellular matrix. The molecular weight of HA is heterogeneous and can reach from several million to several hundred daltons. The effect of HA on cell behavior is size dependent; fragmented HA acts as a danger signal, stimulates cell migration and proliferation and is proinflammatory, native high molecular weight HA suppresses inflammation.

Thoracic skeletal anomalies following surgical treatment of esophageal atresia. Lessons from a national cohort.

Introduction: Thoracotomy as surgical approach for esophageal atresia treatment entails the risk of deformation of the rib cage and consequently secondary thoracogenic scoliosis. The aim of our study was to assess these thoracic wall anomalies on a large national cohort and search for factors influencing this morbidity.

Materials And Methods: Pediatric surgery departments from our national network were asked to send recent thoracic X-ray and operative reports for patients born between 2008 and 2010 with esophageal atresia.

Hyaluronan modulates growth factor induced mammary gland branching in a size dependent manner.

Mammary gland morphogenesis begins during fetal development but expansion of the mammary tree occurs postnatally in response to hormones, growth factors and extracellular matrix. Hyaluronan (HA) is an extracellular matrix polysaccharide that has been shown to modulate growth factor-induced branching in culture. Neither the physiological relevance of HA to mammary gland morphogenesis nor the role that HA receptors play in these responses are currently well understood.

Receptor for hyaluronan mediated motility (RHAMM/HMMR) is a novel target for promoting subcutaneous adipogenesis.

Hyaluronan, CD44 and the Receptor for Hyaluronan-Mediated Motility (RHAMM, gene name HMMR) regulate stem cell differentiation including mesenchymal progenitor differentiation. Here, we show that CD44 expression is required for subcutaneous adipogenesis, whereas RHAMM expression suppresses this process. We designed RHAMM function blocking peptides to promote subcutaneous adipogenesis as a clinical and tissue engineering tool.

Uropathogenic E. coli (UPEC) Infection Induces Proliferation through Enhancer of Zeste Homologue 2 (EZH2).

Unlabelled: Host-pathogen interactions can induce epigenetic changes in the host directly, as well as indirectly through secreted factors. Previously, uropathogenic Escherichia coli (UPEC) was shown to increase DNA methyltransferase activity and expression, which was associated with methylation-dependent alterations in the urothelial expression of CDKN2A. Here, we showed that paracrine factors from infected cells alter expression of another epigenetic writer, EZH2, coordinate with proliferation.

Uncovering the dual role of RHAMM as an HA receptor and a regulator of CD44 expression in RHAMM-expressing mesenchymal progenitor cells.

The interaction of hyaluronan (HA) with mesenchymal progenitor cells impacts trafficking and fate after tissue colonization during wound repair and these events contribute to diseases such as cancer. How this interaction occurs is poorly understood. Using 10T½ cells as a mesenchymal progenitor model and fluorescent (F-HA) or gold-labeled HA (G-HA) polymers, we studied the role of two HA receptors, RHAMM and CD44, in HA binding and uptake in non-adherent and adherent mesenchymal progenitor (10T½) cells to mimic aspects of cell trafficking and tissue colonization.

Identification, design and synthesis of tubulin-derived peptides as novel hyaluronan mimetic ligands for the receptor for hyaluronan-mediated motility (RHAMM/HMMR).

Fragments of the extracellular matrix component hyaluronan (HA) promote tissue inflammation, fibrosis and tumor progression. HA fragments act through HA receptors including CD44, LYVE1, TLR2, 4 and the receptor for hyaluronan mediated motility (RHAMM/HMMR). RHAMM is a multifunctional protein with both intracellular and extracellular roles in cell motility and proliferation.