Expression of WNT-5a and ROR2 correlates with disease severity in osteosarcoma.

Osteosarcoma, a common malignancy primarily affecting children, generally has a poor prognosis. Novel diagnostic, prognostic and therapeutic markers are required to ameliorate the negative outcomes of this disease. We investigated two potential markers, WNT-5a and ROR2, which are hypothesized to dysregulate WNT signaling pathways to promote tumorigenesis in other types of cancer. We investigated WNT-5a and ROR2 expression using immunohistochemistry in 42 osteosarcoma and 12 osteochondroma specimens, and compared the expression of these proteins with one another as well as with clinicopathological parameters. WNT-5a was detected in 34/42 (81.0%) cases and ROR2 was detected in 31/42 (73.8%) cases, significantly higher than in osteochondroma (16.7 and 25.0%, respectively; both P<0.05). Expression of these proteins was positively correlated (r=0.552, P<0.05). Furthermore, expression of WNT-5a and ROR2 was both correlated with Enneking surgical stage and tumor metastasis (P<0.05), but not with patient gender, age or pathological type. Thus, WNT-5a and ROR2 were more highly expressed in more severe disease states, and therefore may play a coordinated role in the occurrence and progression of osteosarcoma.