(HealthDay News) – ROR2 gene mutations are expressed in a subset of soft-tissue sarcomas, including leiomyosarcoma (LMS), gastrointestinal stromal tumors (GIST), and desmoid-type fibromatosis (DTF), and expression may be indicative of poor prognosis, according to a study published online January 4 in The Journal of Pathology.
Badreddin Edris, from the Stanford University School of Medicine in California, and colleagues conducted an initial screen of gene-expression data for 48 receptor tyrosine kinases in 148 sarcomas, as well as immunohistochemical verification of the results. In vivo studies using a xenotransplantation model of LMS were performed and the association between clinico-pathologic features and patient outcome was assessed.
The researchers found that ROR2 was expressed in a subset of LMS, GIST, and DTF. These results were verified in 573 tissue samples from 59 sarcoma tumors types. ROR2 expression was involved in invasion of LMS and GIST cells in vitro. In vivo studies showed that knockdown of ROR2 significantly reduced tumor mass. For patients with LMS and GIST, ROR2 expression, as measured by immunohistochemistry, predicted poor clinical outcome; although, in multivariate analysis, it was not independent of other clinico-pathologic features. ROR2 expression was maintained both in primary tumors and metastases.