Background. The spondin-2 (SPON2) gene is overexpressed in multiple malignant tumors and may promote tumor aggressiveness. However, its expression profile and functional roles in clear cell renal cell carcinoma (ccRCC) are still unclear. Methods. SPON2 expression in ccRCC was evaluated using expression data from TCGA and GEO databases, then confirmed by local patient population (94 patients). The clinical significance of SPON2 expression was evaluated. Downregulation of SPON2 was performed using small-interfering RNA (siRNA). The effects of SPON2 silencing on cell proliferation, apoptosis, invasion, and migration in vitro were investigated. Results. SPON2 was overexpressed in the majority of the ccRCC at both mRNA and protein levels. SPON2 expression was significantly correlated with stage, grade, and recurrence (all ) in patients with localized ccRCC. The receiver operating characteristic (ROC) curve showed that SPON2 expression could serve as a predictor of recurrence. SPON2 expression was significantly associated with recurrence-free survival (RFS) in patients with localized ccRCC. Knocking down SPON2 resulted in suppressed cell invasion and migration in vitro. Conclusion. SPON2 expression might function as a prognostic biomarker in patients with localized ccRCC.

中文翻译：

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Spondin-2 的过表达与局部透明细胞肾细胞癌患者的无复发生存相关。

背景。spondin-2 (SPON2) 基因在多种恶性肿瘤中过度表达，并可能促进肿瘤侵袭性。然而，其在透明细胞肾细胞癌 (ccRCC) 中的表达谱和功能作用仍不清楚。方法。使用来自 TCGA 和 GEO 数据库的表达数据评估 ccRCC 中的 SPON2 表达，然后由当地患者群体（94 名患者）确认。评估了 SPON2 表达的临床意义。使用小干扰 RNA (siRNA) 进行 SPON2 的下调。研究了 SPON2 沉默对体外细胞增殖、凋亡、侵袭和迁移的影响。结果。SPON2 在大多数 ccRCC 的 mRNA 和蛋白质水平上都过表达。SPON2 表达与分期、分级和复发显着相关（所有)在局部 ccRCC 患者中。受试者工作特征（ROC）曲线显示 SPON2 表达可以作为复发的预测因子。SPON2 表达与局部 ccRCC 患者的无复发生存期 (RFS) 显着相关。敲除 SPON2 导致体外细胞侵袭和迁移受到抑制。结论。SPON2 表达可能作为局部 ccRCC 患者的预后生物标志物。