Patched-one or smoothened gene mutations are infrequent in chondrosarcoma.
Constitutive hedgehog signaling has been implicated in the tumorigenesis of cartilaginous neoplasia; however, a common mutational mechanism remains unknown. Some tumors exhibiting hedgehog pathway activation such as basal cell cancer frequently harbor PATCHED-ONE (PTCH-1) or SMOOTHENED (SMO) gene mutations. We therefore asked whether mutations of the hedgehog receptor genes PTCH-1 or SMO occur in cartilage tumors. Singlestrand conformation polymorphism (SSCP) analysis with subsequent manual sequencing was performed to detect alterations of PTCH-1 and SMO in 46 cartilage tumors. SSCP detected five shifts in the PTCH-1 gene and two shifts in SMO. Direct DNA sequencing revealed the five shifts in PTCH-1 were caused by silent nucleotide alterations. The two SMO shifts were the result of the same missense mutation (783G>A) and occurred in one dedifferentiated chondrosarcoma and a synovial chondromatosis. The patient with chondromatosis also carried this same mutation in the germline. However, this mutation was also identified in leukocyte DNA from three of 127 (2.4%) control subjects without cartilage tumors, suggesting it may represent a rare SMO variant. Constitutive activation of the hedgehog signaling pathway in chondrosarcoma is rarely caused by PTCH-1 or SMO mutations. [corrected]
Department of Orthopaedic Oncology, People's Hospital, Beijing University, Beijing, China.
Taiqiang
T
Yan
Mark
M
Angelini
Benjamin A
BA
Alman
Irene L
IL
Andrulis
Jay S
JS
Wunder
D001859:Bone Neoplasms / Q000235:genetics*; D002813:Chondrosarcoma / Q000235:genetics*; D004252:DNA Mutational Analysis; D018095:Germ-Line Mutation; D006801:Humans; D020125:Mutation, Missense; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D018807:Polymorphism, Single-Stranded Conformational; D011956:Receptors, Cell Surface / Q000235:genetics*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D000072086:Smoothened Receptor
C000606236:PTCH1 protein, human; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C491023:SMO protein, human; D000072086:Smoothened Receptor