Abstract
BACKGROUND Osteosarcoma is a major bone malignancy in children and young adults, and it is highly heterogeneous. The clinical outcome of osteosarcoma is individual-dependent due to different genetic and pathological profiles. Although chemotherapy in combination with surgery has significantly improved the survival of localized disease, the prognostic improvement for metastatic patients is less marked. ECT2 (epithelial cell transforming sequence 2) is a transforming protein that can interact with Rho-like proteins of the Ras family and has been proven as an ontogenetic protein in cancer cell lines. We studied the clinical significance of ECT2 in osteosarcoma and explored its underlying oncogenic mechanisms. MATERIAL AND METHODS The protein expression pattern of ECT2 in osteosarcoma was investigated by immunohistochemical staining, and its association with clinicopathological characteristics was initially explored. The significance of ECT2 in predicting patient prognosis was verified by univariate and multivariate analyzes. Cellular experiments were conducted to explore underlying mechanisms of ECT2 in regulating osteosarcoma progression. RESULTS High ECT2 expression was correlated with tumor metastasis and poor overall survival of osteosarcoma patients. ECT2 promotes cell invasion by modulating EMT process. CONCLUSIONS ECT2 is an independent prognostic factor for osteosarcoma and it can upregulate the metastatic capacity of osteosarcoma cells.