■泛素特异性肽酶7(USP7)在多种人类癌症中上调,包括卵巢癌;然而,它在后者中的功能作用在很大程度上仍然未知。
■我们进行了定量实时PCR,以检测USP7,TRAF4和RSK4在卵巢癌细胞系中的表达。此外,蛋白质印迹用于确定USP7,TRAF4,RSK4,PI3K,和AKT(蛋白激酶B,免疫组化染色检测组织中PKB)蛋白水平和USP7表达。3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四唑溴化物测定用于评估细胞活力,transwell分析,以评估细胞迁移和侵袭,和免疫共沉淀以评估TRAF4泛素化。
■结果显示USP7和TRAF4上调,和RSK4在卵巢癌细胞系中的下调。击倒USP7抑制了生存能力,迁移,和侵袭卵巢癌细胞;TRAF4敲低和RSK4过表达在卵巢癌细胞中具有相似的作用。TRAF4被USP7去泛素化并稳定,而RSK4被TRAF4负调控。小鼠异种移植模型证实敲低USP7通过调节TRAF4/RSK4/PI3K/AKT轴来抑制卵巢肿瘤生长。
■击倒USP7减少了增殖,迁移,和卵巢癌细胞的侵袭和抑制小鼠卵巢肿瘤的生长。机械上,USP7增加TRAF4泛素化,促进其降解并导致RSK4上调。
UNASSIGNED: Ubiquitin-specific peptidase 7 (USP7) is upregulated in multiple human cancers, including ovarian cancer; however, its functional role in the latter remains largely unknown.
UNASSIGNED: We conducted quantitative real-time PCR to detect the expression of USP7, TRAF4, and RSK4 in ovarian cancer cell lines. In addition, Western blotting served to determine USP7, TRAF4, RSK4, PI3K, and AKT (protein kinase B,PKB) protein levels and USP7 expression in the tissues was detected by immunohistochemical staining. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to evaluate cell viability, transwell assays to evaluate cell migration and invasion, and co-immunoprecipitation to evaluate TRAF4 ubiquitination.
UNASSIGNED: The results showed USP7 and TRAF4 upregulation, and RSK4 downregulation in ovarian cancer cell lines. Knocking down USP7 suppressed viability, migration, and invasion of ovarian cancer cells; TRAF4 knockdown and RSK4 overexpression had similar effects in ovarian cancer cells. TRAF4 is deubiquitinated and stabilized by USP7, whereas RSK4 is negatively regulated by TRAF4. A mouse xenograft model confirmed that knocking down USP7 suppressed ovarian tumor growth by regulating the TRAF4/RSK4/PI3K/AKT axis.
UNASSIGNED: Knocking down USP7 decreased the proliferation, migration, and invasion of ovarian cancer cells and suppressed ovarian tumor growth in mice. Mechanistically, USP7 increased TRAF4 ubiquitination, promoting its degradation and leading to RSK4 upregulation.