Differences In Molecular Features Between Condylar Osteochondromaand Type Ⅰ Condylar Hyperplasia

Objective: Our research is to compare the molecular features of Condylar Osteochondroma and Type I Condylar Hyperplasia.Materials and methods: The CT data of 4 cases of type I condyle hyperplasia and 9cases of condyle osteochondroma were collected in our hospital.The tissue sections were stained with TRAP,safranin-fast green.Cartilaginous and osteogenic gene differences were detected by real-time PCR and IHC staining.The proliferation capacity of OC and CH was compared using real-time PCR,immunofluorescence,IHC staining and cellular proliferation assays.Results: COL2α1,Sox9,PCNA,Nestin,OCT4,Cyclin D1,G2,MIP,TGF-β1,FGF-2,IGF-1 are highly expressed in condyle osteochondroma.COL1α2 and Runx2 are highly expressed in type I condyle hyperplasia.There was no statistical difference in the expression of COL10α1,Sox2 and IGF-1R.The proliferation rate of chondrocytes in condyle osteochondroma was faster than that of type I CH(P<0.05).Conclusion: These indexes provide a reference for OC and CH histopathological identification.OC has a higher proliferation rate than CH,which may be driven by abundant growth factors in aberrant condyle foci,promoting chondrocyte proliferation.Chondrocytes in condylar osteochondroma overexpress Sox9 gene and reduce the expression of RUNX2,which proves that its etiology is related to early differentiated chondrocytes.Condylar hyperplasia is related to abnormal endochondral ossification.