Notochordal cells: A potential therapeutic option for intervertebral disc degeneration.

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal degenerative disorder worldwide, and ~40% of chronic low back pain cases are associated with IDD. Although the pathogenesis of IDD remains unclear, the reduction in nucleus pulposus cells (NPCs) and degradation of the extracellular matrix (ECM) are critical factors contributing to IDD. Notochordal cells (NCs), derived from the notochord, which rapidly degrades after birth and is eventually replaced by NPCs, play a crucial role in maintaining ECM homeostasis and preventing NPCs apoptosis. Current treatments for IDD only provide symptomatic relief, while lacking the ability to inhibit or reverse its progression. However, NCs and their secretions possess anti-inflammatory properties and promote NPCs proliferation, leading to ECM formation. Therefore, in recent years, NCs therapy targeting the underlying cause of IDD has emerged as a novel treatment strategy. This article provides a comprehensive review of the latest research progress on NCs for IDD, covering their biological characteristics, specific markers, possible mechanisms involved in IDD and therapeutic effects. It also highlights significant future directions in this field to facilitate further exploration of the pathogenesis of IDD and the development of new therapies based on NCs strategies.

Chordoma concurrent with benign notochordal cell tumor of the mobile spine. Should the chordoma part be biopsied? - A stepwise approach for management.

Some evidence suggests that benign notochordal tumors (BNCTs) could be a potential precursor of chordoma. We present an educational rare case of lumbar vertebral BNCTs concomitant with a destructive lesion not reachable on biopsy but thought to be chordoma. We present a stepwise approach for management of these difficult entities based on radiological features.

Ecchordosis Physaliphora: Does It Even Exist?

The term ecchordosis physaliphora (EP) has been used historically to describe a benign notochordal remnant with no growth potential, most commonly occuring in the central clivus. Unfortunately, the radiologic appearance of EP overlaps considerably with the appearance of low-grade chordomas, which do have the potential for growth. In this article, we review new pathologic terminology that better describes this family of diseases, and we propose new radiologic terms that better address the uncertainty of the radiologic diagnosis. The surgical importance of accurate terminology and the implications for patient care are discussed.

Transcriptional Profiling Supports the Notochordal Origin of Chordoma and Its Dependence on a TGFB1-TBXT Network.

Chordoma is a rare malignant tumor demonstrating notochordal differentiation. It is dependent on brachyury (TBXT), a hallmark notochordal gene and transcription factor, and shares histologic features and the same anatomic location as the notochord. This study involved a molecular comparison of chordoma and notochord to identify dysregulated cellular pathways. The lack of a molecular reference from appropriate control tissue limits our understanding of chordoma and its relationship to notochord. Therefore, an unbiased comparison of chordoma, human notochord, and an atlas of normal and cancerous tissue was conducted using gene expression profiling to clarify the chordoma/notochord relationship and potentially identify novel drug targets. The study found striking consistency in gene expression profiles between chordoma and notochord, supporting the hypothesis that chordoma develops from notochordal remnants. A 12-gene diagnostic chordoma signature was identified and the TBXT/transforming growth factor beta (TGF-ß)/SOX6/SOX9 pathway was hyperactivated in the tumor, suggesting that pathways associated with chondrogenesis were a central driver of chordoma development. Experimental validation in chordoma cells confirmed these findings and emphasized the dependence of chordoma proliferation and survival on TGF-ß. The computational and experimental evidence provided the first molecular connection between notochord and chordoma and identified core members of a chordoma regulatory pathway involving TBXT. This pathway provides new therapeutic targets for this unique malignant neoplasm and highlights TGF-ß as a prime druggable candidate.

Ecchordosis physaliphora presenting as hypnic headache.

Ecchordosis physaliphora (EP) is a rare benign congenital hamartomatous lesion originating from remnants of the notochord. EP has never been associated with hypnic headache before. We report for the first time two cases of EP associated with an hypnic headache. The latter is a form of sleep-related nocturnal headache whose pathogenesis has not been fully elucidated. A 61-year-old woman and a 41-year-old man had been complaining of a dull headache that woke them up every night for many months. In both cases, an enlarged cystic lesion in the prepontine cistern, compatible with ecchordosis physaliphora, was found on brain MRI. A diagnosis of hypnic headache secondary to EP was made. Ecchordosis physaliphora presenting as hypnic headache had never been described before. The low prevalence of both conditions (EP and HH) and their presence in two cases might suggest a possible causal association between the two conditions.

Unrecognized notochordal lesions as a likely cause of idiopathic clival cerebrospinal fluid leaks.

OBJECTIVE: To examine an association between idiopathic transclival cerebrospinal fluid (CSF) leak and notochordal lesions. METHODS: This study consisted of the illustrations of institutional patients who underwent surgery for transclival CSF leak between January 1, 2009 and April 25, 2020 and comprehensive review of the existing literature conducted on April 25, 2020. The cases were classified based on the presumed etiologies that were originally proposed in the articles ("idiopathic" vs. "secondary"). The baseline characteristics were compared between the groups, and the surgical outcomes were summarized. RESULTS: In 3 institutional cases, ecchordosis physaliphora (EP) was confirmed at the fistula either pathologically (1) or radiologically (2). Among 42 literature cases, 28 were recognized as idiopathic, while 14 were secondary cases with histologically (n = 12) or radiologically (n = 2) confirmed notochordal lesion at the fistula. Thus, any notochordal lesions were histologically confirmed in 13 among a total of 45 cases (28.9%). Fourteen of the idiopathic cases had undescribed radiographic signs suggestive of small ecchordosis physaliphora at the fistula. Both idiopathic and secondary cases demonstrated resemblance in their ages (mean, 51.4 and 56.6 years; p = 0.102), female predominance (male, 36% vs. 25%; P = 0.521), no association with obesity (7% vs. 18%; P = 0.350) or increased intracranial pressure (7% vs. 6%; P = 1.000). All the fistulas were in the midline or paramidline clivus within several millimeters below the dorsum sellae. All the patients were treated surgically with a multilayer closure, resulting in a success rate of 93% with one surgery. CONCLUSION: Our analyses suggest the association of transclival CSF leak and notochord lesions. A prospective study is needed for definitive conclusion.

Effect of monosultap on notochord development in zebrafish (Danio rerio) embryos.

Monosultap (Mon) is a broad-spectrum insecticide used in agricultural production to control stem borers in rice fields. Currently, little evidence shows how Mon affects notochord development in zebrafish (Danio rerio). In our study, zebrafish embryos were exposed to 0.25, 0.5, and 0.75 mg/L Mon to determine the effects of different concentrations of Mon on notochord development. Mon exposure reduced the body length, decreased the heart rate and hatchability, and induced notochord deformity in zebrafish. The effects of Mon exposure on the internal organization of the notochord and the structural abnormalities were determined based on histological staining of paraffinized tissue sections. Quantitative polymerase chain reaction (qPCR) and in situ hybridization findings revealed that the expression levels of genes related to notochord development (shha, col2a, and ptch2) showed an increasing trend in a concentration-dependent manner. An abnormal increase of apoptosis and cell proliferation in some parts of the notochord suggested that Mon exposure could cause developmental abnormality of the notochord. This study revealed the toxicity of Mon in notochord development. Our findings provide information in assessing the risk of Mon to the ecological environment and human health.

Possible notochordal chordoma in a fossil fish from the Late Cretaceous of Lebanon.

OBJECTIVE: To describe a case of an expansive endocavitary lesion at the level of the caudal tract of the vertebral column of a juvenile fish (Pycnodont) from the Late Cretaceous (Cenomanian) of Lebanon (Hjoula). MATERIALS: The specimen is part of the Paleontological Collection of the University Museum of Chieti, Italy, Inventory Number P #23752. METHODS: The specimen was observed macroscopically, as well as under the stereo-microscope (Leica Wild M 8); aspersion with ethanol and razing light were used to improve the observations and to take micro-photos. RESULTS: The fossil juvenile fish has a visibly altered macroscopic anatomical morphology at the level of the caudal part of the vertebral column, which is pathological in comparison with the normal anatomy of the Pycnodonts. CONCLUSIONS: Although diagnosis cannot be certain, comparative analysis notes morphological and topographic affinity between the paleopathological case described here and notochordal chordoma, which affects some living fish. SIGNIFICANCE: This lesion represents the first case of a nonosseous tumor in a fossil fish, and suggests that this type of neoplasm was among the first of the neoplastic diseases to appear on Earth. LIMITATIONS: Diagnosis rendered from fossil remains is complex and is further limited by the rarity of the condition in the past. SUGGESTIONS FOR FURTHER RESEARCH: Continued comparative analysis of bony changes noted in this specimen with other fossil and living fish will contribute to our understanding of disease in the Earth's earliest inhabitants.

[Notochordal tumors: From notochord to chordoma]. / Les tumeurs notochordales : de la notochorde au chordome.

The group of notochordal tumors consists of the benign notochordal cell tumor and the conventional, dedifferentiated and poorly differentiated chordomas in the fifth edition of the WHO classification of bone and soft tissue tumors. This update covers recent advances in the knowledge of the histogenesis and biology of these tumors and their implications in terms of diagnosis, prognosis assessment and therapeutic management.

Lung Chordoma: A Discussion.

Chordomas are rare neoplasms arising from remnants of the notochord. We report a case of a 61-year-old woman who underwent workup for bariatric surgery and was found to have bilateral pulmonary nodules on a computed tomographic scan. Video-assisted thoracoscopic wedge resections were performed, and immunohistochemical stains confirmed the diagnosis of chordoma in all lesions. Much of our current knowledge of chordomas comes from axial and extra-axial, nonpulmonary presentations. Surgery appears to be the best treatment option because these tumors are generally chemoresistant. However, there are limited numbers of case reports of this entity.

Patterns of brachyury expression in chordomas.

INTRODUCTION: Chordomas are rare malignant midline tumors, presumed to arise from notochordal remnants. This was further suggested by the discovery of the brachyury in chordomas pathogenesis. Its immunohistochemical expression has become the principal adjunct in the diagnosis of chordomas. However, studies about brachyury expression in chordomas are not fully comparable, mainly because they use different primary antibodies. Thus, the aim of this study is to investigate the expression of brachyury expression in a series of chordomas in conjunction to clinicopathological characteristics and to review the relevant literature providing all the details needed in the immunohistochemical study of brachyury. MATERIALS AND METHODS: This is a retrospective study of 62 chordomas, diagnosed over a 22-year period. No dedifferentiated or poorly differentiated cases were included. A monoclonal primary antibody (clone A-4) was used and brachyury expression was evaluated by the H-score. Clinicopathological parameters studied were age, sex, tumor localization, decalcification status and tissue age. Fetal notochords were used for comparison. RESULTS: Mean H-score of nuclear brachyury expression was 129.8. The tissue age significantly influenced brachyury expression, the older samples expressing less brachyury. Decalcification demonstrated a trend to weaken brachyury expression. Clinical characteristics were not correlated with the patterns of brachyury expression. Notochords were negative. Literature review reveals several polyclonal antibodies used and a positivity of 75%-100% in chordomas with even more variable results in notochords. CONCLUSION: In chordomas, as in other tumor types, an uniformization of studies about brachyury expression is needed, by considering the clone used, and the decalcification and the age of the sample, given the growing importance of brachyury in diagnosis and therapeutic steps.

Lethal extracranial hemorrhage due to intracranial clivalchordoma: An autopsy case.

We present a case of a 48-year-old man's unexpected death affected by a relapsed clivalchordoma. After partial excision surgery of the neoplasm, he manifested 5 days later, in conditions of well-being, a sudden lethal extracranial hemorrhage from nose and mouth. The autopsy examination and the subsequent histological investigations did not allow us to clarify the exact origin of the bleeding. Based on the negativity of the accurate examinations performed, the extent of the bleeding, and the findings highlighted by the means of the nuclear magnetic resonance (NMR) carried out a few days before death, we have considered reasonable to localize the source of hemorrhage in the intrapetrous tract of the left internal carotid artery. Since this is a unique event, never previously documented, we believe that our report may be of interest to the scientific community.

Diastematobulbia type II without associated dermoid tumor: case report.

Split cord malformation (SCM) is a term used for all double spinal cords. It represents 3.8%-5% of spinal dysraphisms. Pang et al.'s embryological theory proposes the formation of an "accessory neurenteric canal" that communicates with the yolk sac and amnion. To the authors' knowledge, only three cases of diastematobulbia (basicranial SCM) associated with a spur or dermoid have been reported in the literature.The case patient is a newborn girl with an occipitocervical meningocele and dermal sinus associated with an anomaly of notochordal development in the transition between the medulla oblongata and the spinal cord (diastematobulbia) without a bony septum or dermoid cyst. The patient also has agenesis of the atlas and an absence of corticospinal tract decussation. This patient underwent reconstruction of the occipital meningocele and dermal sinus excision.To the authors' knowledge, this is the first described case of type II diastematobulbia (basicranial SCM), without a dermoid cyst. The authors analyzed the embryological errors present in the case patient and considered the option of further surgical treatment depending on the evolution of the patient's condition. At the time of this report, the patient had shown normal psychomotor development. However, this fact may only be due to the patient's young age. Considering that after initial untethering the patient remained clinically asymptomatic, conservative and close surveillance has been and continues to be the proposed treatment.

Spontaneous, Intrasphenoidal Rupture of Ecchordosis Physaliphora with Pneumocephalus Captured During Serial Imaging and Clinical Follow-Up: Pathoanatomic Features and Management.

BACKGROUND: Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intrasphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid leak, definitively captured over serial imaging during clinical and radiologic surveillance. CASE DESCRIPTION: A 68-year old woman with Marfan syndrome presented to the emergency department with the worst headache of her life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a transsphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrated an apparently enlarging transsphenoidal defect which was managed by endoscopic transnasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect. CONCLUSIONS: This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare but potentially significant complications of EP and highlights management options.

New Prospects for Molecular Targets for Chordomas.

Chordomas are malignant, highly recurrent tumors of the midline skeleton that arise from the remnants of the notochord. The development of systemic therapy is critically important to ultimately managing this tumor. Several ongoing trials are attempting to use molecular targeted therapies for mutated pathways in recurrent and advanced chordomas and have shown promise. In addition, immunotherapies, including brachyury-directed vaccination and checkpoint inhibition, have also been attempted with encouraging results. This article discusses the major pathways that have been implicated in the pathogenesis of chordoma with an emphasis on molecular vulnerabilities that future therapies are attempting to exploit.

[From bench to bedside for new treatment paradigms in chordomas: An update]. / Depuis la recherche translationnelle jusqu'aux nouveaux paradigmes thérapeutiques : mise à jour des données dans les chordomes.

Chordomas are rare malignant tumours, which typically occur in the axial skeleton and skull base. They arise from embryonic remnants of the notochord. They constitute less than 5 % of primary bone tumours. They are characterised by their locally aggressive potential with high frequency of recurrences and a median overall survival of 6 years. The initial therapeutic strategy must be discussed in an expert centre and may involve surgery, preoperative radiotherapy, exclusive radiotherapy or therapeutic abstention. Despite this, more than 50 % of patients will be facing recurrences with few therapeutic options available at this advanced stage. This review aims to outline current treatment options available in chordomas, as well as discussing potentiality of new therapeutic approaches through their molecular characterization and the comprehension of their immunological environment.

Ecchordosis physaliphora: a cautionary tale.

BACKGROUND: Ecchordosis physaliphora is a congenital, benign lesion originating from notochordal remnants along the craniospinal axis, most frequently located at the level of the clivus and sacrum. Sometimes ecchordosis physaliphora is difficult to recognise and treat, with a total of twenty-six cases described in the literature. METHODS: This study reports on three cases of previously undiagnosed ecchordosis physaliphora presenting with cerebrospinal fluid rhinorrhoea and meningitis. CONCLUSION: Endoscopic transclival or transsphenoid surgery including three-layer (fat, fascia and nasoseptal flap) reconstruction was used in all cases with complete resolution of the symptoms.

Active receptor tyrosine kinases, but not Brachyury, are sufficient to trigger chordoma in zebrafish.

The aberrant activation of developmental processes triggers diverse cancer types. Chordoma is a rare, aggressive tumor arising from transformed notochord remnants. Several potentially oncogenic factors have been found to be deregulated in chordoma, yet causation remains uncertain. In particular, sustained expression of TBXT - encoding the notochord regulator protein brachyury - is hypothesized as a key driver of chordoma, yet experimental evidence is absent. Here, we employ a zebrafish chordoma model to identify the notochord-transforming potential of implicated genes in vivo We find that Brachyury, including a form with augmented transcriptional activity, is insufficient to initiate notochord hyperplasia. In contrast, the chordoma-implicated receptor tyrosine kinases (RTKs) EGFR and Kdr/VEGFR2 are sufficient to transform notochord cells. Aberrant activation of RTK/Ras signaling attenuates processes required for notochord differentiation, including the unfolded protein response and endoplasmic reticulum stress pathways. Our results provide the first in vivo evidence against a tumor-initiating potential of Brachyury in the notochord, and imply activated RTK signaling as a possible initiating event in chordoma. Furthermore, our work points at modulating endoplasmic reticulum and protein stress pathways as possible therapeutic avenues against chordoma.

Developmental neurotoxicity of maneb: Notochord defects, mitochondrial dysfunction and hypoactivity in zebrafish (Danio rerio) embryos and larvae.

Broad applications and exposure to the fungicide maneb can lead to toxicity in non-target organisms. Maneb is also associated with neurogenerative diseases such as Parkinson's disease (PD). The objectives of this study were to determine the acute toxicity of maneb to zebrafish by measuring mitochondrial bioenergetics, locomotor activity, and the expression of genes related to the oxidative damage response, as well as those related to dopamine signaling due to its association with PD. Zebrafish embryos at 6 h post-fertilization (hpf) were exposed to either solvent control (0.1% DMSO, v/v), or one dose of 0.1, 0.5, 1.0 and 10.0 µM maneb for 96 h. Maneb was moderately toxic to zebrafish embryos, and had a 96-h LC50 value of 4.29 µM (~ 1.14 mg/L). Maneb induced a dose-dependent increase in mortality, decreased hatching rate, and increased notochord deformity rate at both 1.0 and 10.0 µM after 72 and 96 h. Total body length was also significantly reduced with 1.0 µM maneb. A 50-60% decrease in mean basal oxygen consumption rate was also observed in embryos following a 24 hpf exposure to 10.0 µM maneb but oligomycin-induced ATP production and FCCP-induced maximum respiration remained unaffected. No change was detected in the expression levels of genes associated with oxidative stress (sod1 and sod2), nor those related to dopamine synthesis (th1), dopamine transporter (dat), dopamine receptors (drd1, drd2a, drd3, and drd4b). Thus, modifying the expression of these transcripts may not be a mechanism for maneb-induced developmental toxicity in zebrafish. To assess the potential for neurotoxicity, a dark photokinesis assay was conducted in larvae following 7 d exposure to 0.1, 0.5 and 1.0 µM maneb. Larvae exposed to 0.5 and 1.0 µM maneb showed signs related to hypoactivity, and this reduced activity is hypothesized to be associated with notochord defects as this deformity was prevalent at higher concentrations of maneb. Overall, these data demonstrate that maneb negatively affects embryonic development (i.e. notochord development), affects basal oxygen consumption rates of embryos, and induces hypoactivity in larval fish. This study improves understanding regarding the developmental neurotoxicity of the fungicide maneb to zebrafish.

The vacuolated morphology of chordoma cells is dependent on cytokeratin intermediate filaments.

Notochordal cells (NCs), characterized by their vacuolated morphology and coexpression of cytokeratin and vimentin intermediate filaments (IFs), form the immature nucleus pulposus (NP) of the intervertebral disc. As humans age, NCs give way to mature NP cells, which do not possess a vacuolated morphology and typically only express vimentin IFs. In light of their concomitant loss, we investigated the relationship between cytosolic vacuoles and cytokeratin IFs, specifically those containing cytokeratin-8 proteins, using a human chordoma cell line as a model for NCs. We demonstrate that the chemical disruption of IFs with acrylamide, F-actin with cytochalasin-D, and microtubules with nocodazole all result in a significant (p < 0.001) decrease in vacuolation. However, vacuole loss was the greatest in acrylamide-treated cells. Examination of the individual roles of vimentin and cytokeratin-8 IFs in the existence of vacuoles was accomplished using small interfering RNA-mediated RNA interference to knock down either vimentin or cytokeratin-8 expression. Reduction of cytokeratin-8 expression was associated with a less-vacuolated cell morphology. These data demonstrate that cytokeratin-8 IFs are involved in stabilizing vacuoles and that their diminished expression could play a role in the loss of vacuolation in NCs during aging. A better understanding of the NCs may assist in preservation of this cell type for NP maintenance and regeneration.