TrkA + sensory neurons regulate osteosarcoma proliferation and vascularization to promote disease progression.

Bone pain is a presenting feature of bone cancers such as osteosarcoma (OS), relayed by skeletal-innervating peripheral afferent neurons. Potential functions of tumor-associated sensory neurons in bone cancers beyond pain sensation are unknown. To uncover neural regulatory functions, a chemical-genetic approach in mice with a knock-in allele for TrkA was used to functionally perturb sensory nerve innervation during OS growth and disease progression. TrkA inhibition in transgenic mice led to significant reductions in sarcoma-associated sensory innervation and vascularization, tumor growth and metastasis, and prolonged overall survival. Single-cell transcriptomics revealed that sarcoma denervation was associated with phenotypic alterations in both OS tumor cells and cells within the tumor microenvironment, and with reduced calcitonin gene-related peptide (CGRP) and vascular endothelial growth factor (VEGF) signaling. Multimodal and multi-omics analyses of human OS bone samples and human dorsal root ganglia neurons further implicated peripheral innervation and neurotrophin signaling in OS tumor biology. In order to curb tumor-associated axonal ingrowth, we next leveraged FDA-approved bupivacaine liposomes leading to significant reductions in sarcoma growth, vascularity, as well as alleviation of pain. In sum, TrkA-expressing peripheral neurons positively regulate key aspects of OS progression and sensory neural inhibition appears to disrupt calcitonin receptor signaling (CALCR) and VEGF signaling within the sarcoma microenvironment leading to significantly reduced tumor growth and improved survival. These data suggest that interventions to prevent pathological innervation of osteosarcoma represent a novel adjunctive therapy to improve clinical outcomes and survival.

Advanced Ultrasonic Inspection of Thick-Section Composite Structures for In-Field Asset Maintenance.

An investigation into the inspection capabilities of in-field advanced ultrasound detection for use on ultra-thick (20 to 100 mm) glass fibre-reinforced polyester composites is presented. Plates were manufactured using custom moulding techniques, such that delamination flaws were created at calibrated depths. The full matrix capture technique with an on-board total focussing method was used to detect flaws scanned by a 0.5 MHz linear array probe. Flaw through-thickness dimensions were altered to assess the threshold for crack face separation at which delaminations could be identified. Furthermore, part thickness and in-plane flaw dimensions were varied to identify the inspection capability limitations of advanced ultrasonics for thick composites. The results presented in this study demonstrate an inverse relationship between the ability to find delaminations and plate thicknesses, with inspections successful at depths up to 74 mm. When the delamination thickness exhibited surface-to-surface contact, the inspection capability was reduced to 35 mm. There was an exponential decay relationship between the accuracy of the flaw depth measurement and plate thickness, likely due to the necessity of low probe frequencies. The effective inspection depth was determined to be in the range of 1 to 20 times the wavelength. It is speculated that the accuracy of measurements could be improved using probes with novel coupling solutions, and detectors with optimised signal processing/filtration algorithms.

CNTNAP4 signaling regulates osteosarcoma disease progression.

Improved treatment strategies for sarcoma rely on clarification of the molecular mediators of disease progression. Recently, we reported that the secreted glycoprotein NELL-1 modulates osteosarcoma (OS) disease progression in part via altering the sarcomatous extracellular matrix (ECM) and cell-ECM interactions. Of known NELL-1 interactor proteins, Contactin-associated protein-like 4 (Cntnap4) encodes a member of the neurexin superfamily of transmembrane molecules best known for its presynaptic functions in the central nervous system. Here, CRISPR/Cas9 gene deletion of CNTNAP4 reduced OS tumor growth, sarcoma-associated angiogenesis, and pulmonary metastases. CNTNAP4 knockout (KO) in OS tumor cells largely phenocopied the effects of NELL-1 KO, including reductions in sarcoma cell attachment, migration, and invasion. Further, CNTNAP4 KO cells were found to be unresponsive to the effects of NELL-1 treatment. Transcriptomic analysis combined with protein phospho-array demonstrated notable reductions in the MAPK/ERK signaling cascade with CNTNAP4 deletion, and the ERK1/2 agonist isoproterenol restored cell functions among CNTNAP4 KO tumor cells. Finally, human primary cells and tissues in combination with sequencing datasets confirmed the significance of CNTNAP4 signaling in human sarcomas. In summary, our findings demonstrate the biological importance of NELL-1/CNTNAP4 signaling axis in disease progression of human sarcomas and suggest that targeting the NELL-1/CNTNAP4 signaling pathway represents a strategy with potential therapeutic benefit in sarcoma patients.

Conventional Chondrosarcoma with Clear Cell Features in the Rib: Report of Two Cases and Review of the Literature.

A subset of clear cell chondrosarcomas may contain focal areas of low-grade conventional chondrosarcoma; however, it is rare to find foci resembling clear cell chondrosarcoma admixed with areas otherwise typical conventional chondrosarcoma. We report two patients with conventional chondrosarcoma with clear cell features occurring in the rib, one in the setting of multiple hereditary exostoses (MHE) and the other without MHE. Both patients were found to have a destructive rib mass with a soft tissue component and underwent en bloc resection. Histologic examination revealed predominantly grade 2 conventional chondrosarcomas; however, multiple foci containing large cells with pale eosinophilic to clear cytoplasm, distinct cell borders, centrally located nuclei, and conspicuous nucleoli, resembling clear cell chondrosarcoma were identified throughout the specimen. The significance of clear cell features in an otherwise typical conventional chondrosarcoma, to our knowledge, is unknown and deserves recognition. Finally, these tumors highlight the need for careful histologic examination and proper classification as unexpected findings may impact management.

Acetabular Reaming Is a Reliable Model to Produce and Characterize Periarticular Heterotopic Ossification of the Hip.

Heterotopic ossification (HO) is a pathologic process characterized by the formation of bone tissue in extraskeletal locations. The hip is a common location of HO, especially as a complication of arthroplasty. Here, we devise a first-of-its-kind mouse model of post-surgical hip HO and validate expected cell sources of HO using several HO progenitor cell reporter lines. To induce HO, an anterolateral surgical approach to the hip was used, followed by disclocation and acetabular reaming. Animals were analyzed with high-resolution roentgenograms and micro-computed tomography, conventional histology, immunohistochemistry, and assessments of fluorescent reporter activity. All the treated animals' developed periarticular HO with an anatomical distribution similar to human patients after arthroplasty. Heterotopic bone was found in periosteal, inter/intramuscular, and intracapsular locations. Further, the use of either PDGFRα or scleraxis (Scx) reporter mice demonstrated that both cell types gave rise to periarticular HO in this model. In summary, acetabular reaming reproducibly induces periarticular HO in the mouse reproducing human disease, and with defined mesenchymal cellular contributors similar to other experimental HO models. This protocol may be used in the future for further detailing of the cellular and molecular mediators of post-surgical HO, as well as the screening of new therapies.

NELL1 Regulates the Matrisome to Promote Osteosarcoma Progression.

Sarcomas produce an abnormal extracellular matrix (ECM), which in turn provides instructive cues for cell growth and invasion. Neural EGF like-like molecule 1 (NELL1) is a secreted glycoprotein characterized by its nonneoplastic osteoinductive effects, yet it is highly expressed in skeletal sarcomas. Here, we show that genetic deletion of NELL1 markedly reduces invasive behavior across human osteosarcoma (OS) cell lines. NELL1 deletion resulted in reduced OS disease progression, inhibiting metastasis and improving survival in a xenograft mouse model. These observations were recapitulated with Nell1 conditional knockout in mouse models of p53/Rb-driven sarcomagenesis, which reduced tumor frequency and extended tumor-free survival. Transcriptomic and phosphoproteomic analyses demonstrated that NELL1 loss skews the expression of matricellular proteins associated with reduced FAK signaling. Culturing NELL1 knockout sarcoma cells on wild-type OS-enriched matricellular proteins reversed the phenotypic and signaling changes induced by NELL1 deficiency. In sarcoma patients, high expression of NELL1 correlated with decreased overall survival. These findings in mouse and human models suggest that NELL1 expression alters the sarcoma ECM, thereby modulating cellular invasive potential and prognosis. Disruption of NELL1 signaling may represent a novel therapeutic approach to short-circuit sarcoma disease progression. SIGNIFICANCE: NELL1 modulates the sarcoma matrisome to promote tumor growth, invasion, and metastasis, identifying the matrix-associated protein as an orchestrator of cell-ECM interactions in sarcomagenesis and disease progression.

NGF-p75 signaling coordinates skeletal cell migration during bone repair.

Bone regeneration following injury is initiated by inflammatory signals and occurs in association with infiltration by sensory nerve fibers. Together, these events are believed to coordinate angiogenesis and tissue reprogramming, but the mechanism of coupling immune signals to reinnervation and osteogenesis is unknown. Here, we found that nerve growth factor (NGF) is expressed following cranial bone injury and signals via p75 in resident mesenchymal osteogenic precursors to affect their migration into the damaged tissue. Mice lacking Ngf in myeloid cells demonstrated reduced migration of osteogenic precursors to the injury site with consequently delayed bone healing. These features were phenocopied by mice lacking p75 in Pdgfra+ osteoblast precursors. Single-cell transcriptomics identified mesenchymal subpopulations with potential roles in cell migration and immune response, altered in the context of p75 deletion. Together, these results identify the role of p75 signaling pathway in coordinating skeletal cell migration during early bone repair.

Grade 1 and 2 Chondrosarcomas of the Chest Wall: CT Imaging Features and Review of the Literature.

The purpose of our retrospective article is to review the CT imaging features of chondrosarcomas of the chest wall with pathologic correlation. For 26 subjects with biopsy-proven chondrosarcomas of the chest wall, two musculoskeletal radiologists retrospectively reviewed 26 CT scans in consensus. Descriptive statistics were performed. The mean tumor size was 57 mm. Twenty (20/26, 77%) chondrosarcomas were located in the ribs and six (6/26, 23%) in the sternum. The majority were lytic (19/26, 73%) with <25% calcification (15/26, 58%), and with a soft tissue mass (22/27, 85%). In this study CT features of grade 1 chondrosarcoma overlapped with those of grade 2 tumors. In conclusion, chondrosarcomas of the chest wall are generally lytic with an associated soft tissue mass, showing little calcified matrix and low-to-intermediate grade.

Experimental Study on the Interlaminar Fracture Properties of Carbon Fibre Reinforced Polymer Composites with a Single Embedded Toughened Film.

In this study, two types of single polymer films have been inserted in a composite laminate to examine their toughening effects on mechanical properties. The first is a thermoplastic polyurethane (PU) film, and the second is an adhesive epoxy film featuring a polyester net. The laminates were manufactured either using a co-curing (CC) process or a secondary bonding (SB) process used for the epoxy film. Mode I and mode II interlaminar fracture toughness were measured for laminates manufactured by both processes and compared with the corresponding reference laminate toughness. A significant increase in both mode I and mode II toughness resulted when introducing a single PU film, approximately 290% and 50%, respectively. Similarly, the epoxy film improved the interlaminar fracture properties; the CC process produced an increase of 175% for mode II toughness, while the SB adhesive film showed an increase of 75% for mode II toughness.

Intravascular Mesenchymal Chondrosarcoma of the Femoral Vein: A Case Report.

CASE: A 30-year-old man presented with progressive lower right extremity pain and swelling, initially diagnosed as a deep venous thrombosis. He returned 18 months later after 2 episodes of gross hemoptysis, with chest computed tomography angiography findings concerning for tumor thrombus in the left pulmonary artery. Subsequent advanced imaging showed a lesion arising from his right femoral vein, which open biopsy revealed to be a primary intravascular mesenchymal chondrosarcoma. He underwent medical therapy, with improvement of pain and swelling and successful return to work. CONCLUSION: Mesenchymal chondrosarcoma is a rare pathology, and its intravascular origin makes this case extraordinarily uncommon.

Chondrosarcoma of the spine: a narrative review.

Chondrosarcoma is an uncommon primary bone tumor with an estimated incidence of 0.5 per 100,000 patient-years. Primary chondrosarcoma of the mobile spine and sacrum cumulatively account for less than 20% of all cases, most .commonly causing patients to present with focal pain with or without radiculopathy, or myelopathy secondary to neural element compression. Because of the rarity, patients benefit from multidisciplinary care at academic tertiary-care centers. Current standard-of-care consists of en bloc surgical resection with negative margins; for high grade lesions adjuvant focused radiation with ≥60 gray equivalents is taking an increased role in improving local control. Prognosis is dictated by lesion grade at the time of resection. Several groups have put forth survival calculators and epidemiological evidence suggests prognosis is quite good for lesions receiving R0 resection. Future efforts will be focused on identifying potential chemotherapeutic adjuvants and refining radiation treatments as a means of improving local control.

Chordoma of the sacrum and mobile spine: a narrative review.

Chordoma is a notochord-derived primary tumor of the skull base and vertebral column known to affect 0.08 to 0.5 per 100,000 persons worldwide. Patients commonly present with mechanical, midline pain with or without radicular features secondary to nerve root compression. Management of these lesions has classically revolved around oncologic resection, defined by en bloc resection of the lesion with negative margins as this was found to significantly improve both local control and overall survival. With advancement in radiation modalities, namely the increased availability of focused photon therapy and proton beam radiation, high-dose (>50 Gy) neoadjuvant or adjuvant radiotherapy is also becoming a standard of care. At present chemotherapy does not appear to have a role, but ongoing investigations into the ontogeny and molecular pathophysiology of chordoma promise to identify therapeutic targets that may further alter this paradigm. In this narrative review we describe the epidemiology, histopathology, diagnosis, and treatment of chordoma.

Melanoma metastatic to the hyoid bone.

Metastatic melanoma may be included in the differential diagnosis of hyoid masses in patients with a history of melanoma. Hyoid resection is well tolerated and of diagnostic and therapeutic benefit in patients with tumors metastatic to the hyoid bone.

Clinicopathologic Analysis of Chondroblastoma in Adults: A Single-Institution Case Series.

Chondroblastoma is a rare benign tumor of immature cartilage cells that generally occurs in an epiphyseal location of skeletally immature individuals. However, a few studies have reported cases in older patients. The purpose of this study was to evaluate the clinical, radiographic, and pathologic features of chondroblastoma in an adult population. The pathology archives of our institution were searched for cases of chondroblastoma diagnosed in patients ≥25 years of age. Of 14 patients identified, 8 were male and 6 were female with a median age of 34 years (range = 29-54 years). Most lesions occurred in short bones of hands and feet (N = 7, 50%), followed by the long tubular bones (N = 4, 28%). All demonstrated typical histologic features of chondroblastoma, but more extensive calcification, necrosis, and degenerative changes were also seen. At follow-up (median = 73.5 months), 2 patients (17%) had local recurrence. None had metastasis. In summary, chondroblastoma in adults tends to involve the short bones of the hands and feet and demonstrate histologic changes associated with long-standing growth of a benign tumor.

Epithelioid Sarcoma of the Peripheral Nerve: Clinicopathologic Series of Three Cases and Literature Review.

OBJECTIVES: Epithelioid sarcoma (ES) rarely arises in the nerve. To increase our understanding of this unusual tumor originating in the nerve, we describe the features of three cases and review the literature. METHODS: Clinical data, imaging, pathology, treatment, and follow-up are detailed. A systematic literature review was conducted. RESULTS: Two patients were male and one female; the median age was 24 years. The patients had neurologic symptoms, and the tumors arose in large nerves and ranged from 2.4 to 5.8 cm. The tumors were avid on positron emission tomography-computed tomography and showed increased signal intensity on T2-weighted magnetic resonance imaging. Centered in the nerve, the tumors grew with an infiltrative pattern and encased the nerve fascicles. All were treated with wide resection, and adjuvant treatment included combinations of chemotherapy and radiation. One recurred, and the limb was amputated. Metastases were documented to lymph nodes, lung, pleura, and skin. One patient died of disease after 54 months. Literature review including our cases showed that tumors stained with pancytokeratin (9/9), EMA (4/4), and CD34 (7/7); there was loss of INI1 in all six cases tested. CONCLUSIONS: ES rarely arises in the peripheral nerve, and its infiltrative nature often requires morbid surgery. The differential includes a variety of benign and malignant epithelioid neoplasms.

High-Grade Sarcoma Arising in Association With an Intraosseous Lipoma: A Case Report.

CASE: A 78-year-old man was followed for an incidentally found, asymptomatic lesion in his right proximal femur that was unchanged radiographically for 11 years. He developed pain and was believed to have experienced a stress fracture through the lesion. The lesion was biopsied, showing a high-grade pleomorphic sarcoma with an underlying senescent intraosseous lipoma. He was ultimately treated with wide excision and reconstruction of the proximal femur. CONCLUSION: This case highlights the importance of obtaining a tissue diagnosis for lesions that become symptomatic.

Diagnostic and interventional magnetic resonance neurography diagnosis of brachytherapy seed-mediated pudendal nerve injury: a case report.

Injury to the pudendal nerve in men presents with pain, paresthesia, or numbness of the perineum, and/or scrotum, and/or penis. There is evidence implicating the brachytherapy seeds used to treat prostate cancer as source of pudendal nerve injury. Compared to surgical prostatectomy, brachytherapy has the advantage of being less invasive, but seeds may not only lead to well-established complications such as urinary, bowel, and erectile dysfunction, but also injury to the sensory branches of the pudendal nerve. We report and document a case of pudendal nerve injury secondary to brachytherapy seeds diagnosed with magnetic resonance (MR) neurography, nerve blocks, and histopathological examination; and successful treatment via sensory branch neurectomy.

Endogenous CCN family member WISP1 inhibits trauma-induced heterotopic ossification.

Heterotopic ossification (HO) is defined as abnormal differentiation of local stromal cells of mesenchymal origin, resulting in pathologic cartilage and bone matrix deposition. Cyr61, CTGF, Nov (CCN) family members are matricellular proteins that have diverse regulatory functions on cell proliferation and differentiation, including the regulation of chondrogenesis. However, little is known regarding CCN family member expression or function in HO. Here, a combination of bulk and single-cell RNA sequencing defined the dynamic temporospatial pattern of CCN family member induction within a mouse model of trauma-induced HO. Among CCN family proteins, Wisp1 (also known as Ccn4) was most upregulated during the evolution of HO, and Wisp1 expression corresponded with chondrogenic gene profile. Immunohistochemistry confirmed WISP1 expression across traumatic and genetic HO mouse models as well as in human HO samples. Transgenic Wisp1LacZ/LacZ knockin animals showed an increase in endochondral ossification in HO after trauma. Finally, the transcriptome of Wisp1-null tenocytes revealed enrichment in signaling pathways, such as the STAT3 and PCP signaling pathways, that may explain increased HO in the context of Wisp1 deficiency. In sum, CCN family members, and in particular Wisp1, are spatiotemporally associated with and negatively regulate trauma-induced HO formation.

Novel lactone-layered double hydroxide ionomer powders for bone tissue repair.

This article describes the use of a novel lactone-layered double hydroxide polymer network (PN), derived from a poly(lactide-co-caprolactone) copolymer, as a controlled ion-release agent for artificial bone tissue regeneration. The osteogenic cell culture Saos-2 is used as a test culture to investigate the PN's performance as an extracellular ion-release agent. The compelling performance of this PN is demonstrated in both growth and osteogenic media compared with a control of cells grown on tissue culture plastic (TCP) without PN. Firstly, the PNs released concentration of magnesium ions over time ranging from 10 to 60 mM after 24 hr, depending on the PN sample. After incubation of Saos-2 with the PN, while no difference was seen in cell number, there was significant upregulation of bone-related gene expression at 14 days-~5fold increase in Bone Morphogenetic Protein 2, ~3fold increase in osteopontin and ~2fold increase in collagen Type I. In addition, normalized alkaline phosphatase activity was seen to significantly increase by ~2fold with PN presence. A ~4fold increase in collagen Type I protein expression (via Gomori Trichrome Stain) was observed with PN presence. In addition, a ~4fold increase in phosphate deposits (as seen with Von Kossa staining analysis) was seen with PN presence. It is found that this novel PN material has a significant potential for bone tissue regeneration.