promotes the proliferation, invasion and migration of Wilms' tumor and can be used as a prognostic factor.

PURPOSE

Overexpression of has been reported in many tumors, where it promotes tumorigenesis and progression, as well as correlates with the prognosis of different malignancies. However, expression and its function have rarely been reported in Wilms' tumor (WT). This study aimed to reveal the clinical significance of expression in patients with WT and determine its mechanisms.

MATERIALS AND METHODS

We analyzed the expression of and its correlations with various clinicopathological features in 72 WT tissues and 72 adjacent non-cancerous tissues by immunohistochemistry. Cox proportional hazards regression models were used to investigate the correlations between expression and the prognosis of WT patients. Fresh frozen samples from 20 WT patients were examined using Western blotting (WB) and real-time quantitative polymerase chain reaction (RT-qPCR). In WT cell line, after knockdown by sh- and growth arrest-specific 6 (Gas6) stimulation, the cell proliferation, migration and invasion abilities were detected by methyl-thiazolyl-tetrazolium (MTT), clone-forming, wound-healing and transwell assays. Meanwhile, the tumor-forming ability was tested on nude mice xenograft models. Finally, the expression of several proteins in signal pathways was quantified by WB assays.

RESULTS

Compared with the adjacent non-cancerous tissues, the expression of was significantly higher in WT tissues (<0.05). High expression of was associated with tumor recurrence or lung metastasis of WT patients and was a prognostic factor for WT patients (<0.05). In vitro assays, the proliferation, migration and invasion of WT cells decreased with knockdown and significantly increased with activation by Gas6 (<0.05). In vivo assays, the ability of tumorigenicity in WT cells reduced dramatically after knockout (<0.05). Moreover, - pathway proteins decreased with knockdown.

CONCLUSION

Our results suggest that is highly expressed in WT and is a prognostic factor, which could promote the progression of WT in vitro and in vivo. It may also be a potential biomarker for WT.