Enchondromas and conventional central chondrosarcomas are, respectively, benign and malignant hyaline cartilage-forming tumours that originate in the medulla of bone. In order to gain a better understanding of the molecular process underlying malignant transformation of enchondroma, and to investigate whether there is a biological difference between conventional central cartilaginous tumours and those of enchondromatosis or with phalangeal localization, a series of 64 enchondromas (phalanx, n = 21; enchondromatosis, n = 15) and 89 chondrosarcomas (phalanx, n = 17; enchondromatosis, n = 13) was collected. Indian Hedgehog (IHH)/parathyroid hormone related peptide (PTHrP) signalling, an important pathway in chondrocyte proliferation and differentiation within the normal growth plate, was studied by immunohistochemical analysis of the expression of PTHrP, PTHR1, Bcl-2, p21, cyclin D1, and cyclin E. Quantitative real-time PCR for IHH, PTCH, SMO, and GLI2 was performed on a subset of tumours. The data show that IHH signalling is absent in enchondromas and central chondrosarcomas, while PTHrP signalling is active. There was no difference in the expression of any of the molecules between 35 enchondromas and 26 grade I central chondrosarcomas, indicating that PTHrP signalling is not important in malignant transformation of enchondroma. Higher expression of PTHR1 and Bcl-2 was associated with increasing histological grade in chondrosarcoma, suggesting involvement in tumour progression. No difference was found between samples from enchondromatosis patients and solitary cases, suggesting no difference in PTHrP signalling. A small subset of phalangeal chondrosarcomas demonstrated down-regulation of PTHrP, which may be related to its more indolent clinical behaviour. Thus, in both enchondromas and central chondrosarcomas, PTHrP signalling is active and independent of IHH signalling, irrespective of the presence or absence of enchondromatosis.
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http://dx.doi.org/10.1002/path.1723 | DOI Listing |
Introduction: Pseudohypoparathyroidism 1A (PHP1A) is the best-known representative of inactivating PTH/PTHrP signaling disorders (iPPSD). The associated phenotype develops over time and often includes hormonal resistances, short stature and osteoma cutis. More complex and very early manifestations have also been reported.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
December 2024
Rare Disease Research Group, Molecular (Epi) Genetics Laboratory, Bioaraba Health Research Institute, Araba University Hospital, Vitoria-Gasteiz, Spain.
Objective: To identify the genetic cause underlying the methylation defect in a patient with clinical suspicion of PHP1B/iPPSD3.
Design: Imprinting is an epigenetic mechanism that allows the regulation of gene expression. The locus is one of the loci within the genome that is imprinted.
Osteoarthritis Cartilage
December 2024
Department of Oral Anatomy and Physiology and TMD, College of Stomatology, the Fourth Military Medical University, Xi'an, China; Department of Oral Anatomy and Physiology and TMD, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China. Electronic address:
Objective: Some cells in temporomandibular joint (TMJ) cartilage undergo proliferation in response to negative pressure, which can be induced in vivo by creating bilateral anterior elevation (BAE). TMJ cartilage harbours CD90-expressing cells, and CD90 expression increases under certain controlled conditions. The parathyroid hormone-related peptide (PTHrP) nuclear localisation segment (NLS) promotes chondrocyte proliferation, and mammalian target of rapamycin (mTOR) signalling plays a regulatory role in promoting PTHrP transcription.
View Article and Find Full Text PDFBiomech Model Mechanobiol
November 2024
Department of Biosystems Science, Institute for Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan.
Secondary ossification and maintenance of the growth plate are crucial aspects of long bone formation. Parathyroid hormone-related protein (PTHrP) has been implicated as a key factor in maintaining the growth plate, and studies suggest that PTHrP expression in the resting zone is closely related with formation of the secondary ossification center (SOC). However, details of the relationship between resting zone PTHrP expression and preservation of the growth plate remain unclear.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
November 2024
Agri-pharmacy Group, School of Biomedical Sciences, Faculty of Health, University of Plymouth, Plymouth, UK.
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