Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many theories of osteochondroma pathogenesis have been advanced. Genetic research into the inherited multiple form, hereditary multiple exostoses, has revealed a new family of tumour suppressor genes denoted EXT. Patterns of EXT gene mutation in hereditary multiple exostoses, in solitary and multiple osteochondromas, and in chondrosarcoma are analogous to those found in other tumour suppressor genes responsible for family cancer traits and associated malignancies. With one exception, most features of osteochondroma behaviour are comparable to those of benign neoplasms. The neoplastic pathogenesis of osteochondromas provides an alternative to the traditional 'skeletal dysplasia' theory to explain the growth disturbance associated with hereditary multiple exostoses. Recent studies on the physiological function of EXT genes are reviewed and implications for osteochondroma 'cell-of-origin' theories are discussed.
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PMID:The neoplastic pathogenesis of solitary and multiple osteochondromas. 1070 4

Hereditary multiple exostoses (HME) is traditionally described as a skeletal dysplasia. However, the discovery that the EXT family of tumour suppressor genes are responsible for HME suggests that it is more appropriate to classify HME as a familial neoplastic trait. In a clinical and radiographic analysis of paired bone length and exostoses number and dimensions in a HME cohort, the local presence of osteochondromas was consistently associated with growth disturbance. In particular, an inverse correlation between osteochondroma size and relative bone length (p<0.01) was found. These data suggest that the growth retardation in HME may result from the local effects of enlarging osteochondromas rather than a skeletal dysplasia effect. This study provides the first clinical rationale for ablation of rapidly enlarging exostoses to reduce growth disturbance.
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PMID:Clinical and radiographic analysis of osteochondromas and growth disturbance in hereditary multiple exostoses. 1073 91

Hereditary multiple exostoses is an autosomal dominant disorder characterised by the presence of multiple osteochondromas, resulting in a variety of skeletal deformities. It is a genetically heterogeneous condition for which two genes, EXT1 and EXT2, have been isolated. The EXT1 gene, located at 8q24, has been shown to harbour mutations in 44-66% of the hereditary multiple exostoses-families. Mutations in the EXT2 gene, located at 11p11-p12, are detected in about 30% of the families. Additional linkage to chromosome 19p suggests the existence of an EXT3 gene. EXT1 has been shown to act as a tumour suppressor gene in hereditary multiple exostoses, resulting in osteochondroma formation when both copies of EXT1 are lost. Diagnostic germ-line mutation analysis is operative in the Clinical Genetic Center Leiden, the Netherlands.
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PMID:[From gene to disease; hereditary multiple exostoses]. 1184 65

Multiple osteochondromas (MO) is characterised by development of two or more cartilage capped bony outgrowths (osteochondromas) of the long bones. The prevalence is estimated at 1:50,000, and it seems to be higher in males (male-to-female ratio 1.5:1). Osteochondromas develop and increase in size in the first decade of life, ceasing to grow when the growth plates close at puberty. They are pedunculated or sessile (broad base) and can vary widely in size. The number of osteochondromas may vary significantly within and between families, the mean number of locations is 15-18. The majority are asymptomatic and located in bones that develop from cartilage, especially the long bones of the extremities, predominantly around the knee. The facial bones are not affected. Osteochondromas may cause pain, functional problems and deformities, especially of the forearm, that may be reason for surgical removal. The most important complication is malignant transformation of osteochondroma towards secondary peripheral chondrosarcoma, which is estimated to occur in 0.5-5%. MO is an autosomal dominant disorder and is genetically heterogeneous. In almost 90% of MO patients germline mutations in the tumour suppressor genes EXT1 or EXT2 are found. The EXT genes encode glycosyltransferases, catalyzing heparan sulphate polymerization. The diagnosis is based on radiological and clinical documentation, supplemented with, if available, histological evaluation of osteochondromas. If the exact mutation is known antenatal diagnosis is technically possible. MO should be distinguished from metachondromatosis, dysplasia epiphysealis hemimelica and Ollier disease. Osteochondromas are benign lesions and do not affect life expectancy. Management includes removal of osteochondromas when they give complaints. Removed osteochondromas should be examined for malignant transformation towards secondary peripheral chondrosarcoma. Patients should be well instructed and regular follow-up for early detection of malignancy seems justified. For secondary peripheral chondrosarcoma, en-bloc resection of the lesion and its pseudocapsule with tumour-free margins, preferably in a bone tumour referral centre, should be performed.
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PMID:Multiple osteochondromas. 1827 66

Hereditary multiple exostoses (HME) is an autosomal-dominant disorder characterized by the development of benign tumours, multiple osteochondromas (exostoses), growing outward from the metaphyses of long bones. Birth prevalence is estimated to be one in 50,000, and the severity of the disease is variable. Osteochondromas may cause complications including pain, deformities and shortening of the long bones, restricted motion of joints, nerve or blood vessel compression, and malignant transformation (5% of cases) in adulthood. HME is a genetically heterogeneous disorder and is associated with mutations in EXT1 or EXT2 genes, which are both tumour suppressor genes. EXT genes encode glycosyltransferases, termed 'exostosins', which are involved in the biosynthesis of heparan sulphate. Enchondromatosis (or Ollier disease) is characterized by the presence of intra-osseous benign cartilaginous tumours. The estimated prevalence of the disease is one in 100,000. An asymmetrical distribution of cartilage lesions is observed in the disease. The number, size and location of the enchondromas can be extremely variable between patients. Clinical problems caused by enchondromas include skeletal deformities, limb length discrepancy, pain and the potential risk for malignant change to chondrosarcoma (20-50% of cases). The condition in which multiple enchondromas is associated with haemangiomas is known as 'Maffucci syndrome'. Ollier disease and Maffucci syndrome are not usually inherited disorders.
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PMID:Hereditary multiple exostoses and enchondromatosis. 1832 80

Multiple Osteochondromas is an autosomal dominant disorder characterised by the presence of multiple osteochondromas and a variety of orthopaedic deformities. Two genes causative of Multiple Osteochondromas, Exostosin-1 (EXT1) and Exostosin-2 (EXT2), have been identified, which act as tumour suppressor genes. Osteochondroma can progress towards its malignant counterpart, secondary peripheral chondrosarcoma and therefore adequate follow-up of Multiple Osteochondroma patients is important in order to detect malignant transformation early.This review summarizes the considerable recent basic scientific and clinical understanding resulting in a multi-step genetic model for peripheral cartilaginous tumorigenesis. This enabled us to suggest guidelines for clinical management of Multiple Osteochondroma patients. When a patient is suspected to have Multiple Osteochondroma, the radiologic documentation, histology and patient history have to be carefully reviewed, preferably by experts and if indicated for Multiple Osteochondromas, peripheral blood of the patient can be screened for germline mutations in either EXT1 or EXT2. After the Multiple Osteochondroma diagnosis is established and all tumours are identified, a regular follow-up including plain radiographs and base-line bone scan are recommended.
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PMID:Multiple osteochondromas: clinicopathological and genetic spectrum and suggestions for clinical management. 2023 60

Peripheral chondrosarcoma (PCS) develops as malignant transformation of an osteochondroma, a benign cartilaginous outgrowth at the bone surface. Its invasive, lobular growth despite low-grade histology suggests a loss of chondrocyte polarity. The known genetics of osteochondromagenesis include mosaic loss of EXT1 or EXT2 in both hereditary and non-hereditary cases. The most frequent genetic aberrations in human PCS also include disruptions of CDKN2A or TP53. In order to test the sufficiency of either of these to drive progression of an osteochondroma to PCS, we added conditional loss of Trp53 or Ink4a/Arf in an Ext1-driven mouse model of osteochondromagenesis. Each additional tumour suppressor silencing efficiently drove the development of growths that mimic human PCS. As in humans, lobules developed from both Ext1-null and Ext1-functional clones within osteochondromas. Assessment of their orientation revealed an absence of primary cilia in the majority of mouse PCS chondrocytes, which was corroborated in human PCSs. Loss of primary cilia may be responsible for the lost polarity phenotype ascribed to PCS. Cilia deficiency blocks proliferation in physeal chondrocytes, but cell cycle deregulation is sufficient to rescue chondrocyte proliferation following deciliation. This provides a basis of selective pressure for the frequent cell-cycle regulator silencing observed in peripheral chondrosarcomagenesis. Mosaic loss of Ext1 combined with loss of cell cycle regulators promotes peripheral chondrosarcomagenesis in the mouse and reveals deficient ciliogenesis in both the model and the human disease, explaining biological behaviour including lobular and invasive growth.
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PMID:Cell cycle deregulation and mosaic loss of Ext1 drive peripheral chondrosarcomagenesis in the mouse and reveal an intrinsic cilia deficiency. 2564 7