Huang Fang, Ling Hairui, Wang Jie
Department of Nephrology, Affiliated Hospital of Youjiang Medical University for Nationalities, 533000, China; Baise Key Laboratory of Molecular Pathology in Tumors, China.
Department of Oncology, Affiliated Hospital of Youjiang Medical University for Nationalities, 533000, China; Baise Key Laboratory of Molecular Pathology in Tumors, China.
Exp Cell Res. 2025 Feb 1;445(1):114409. doi: 10.1016/j.yexcr.2025.114409. Epub 2025 Jan 6.
Apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1) is involved in regulating the proliferation, invasion, migration, and other malignant progression of various cancer cells. However, its mechanism in clear cell renal cell carcinoma (ccRCC) remains unclear.
UALCAN database was performed to predict APEX1 expression in ccRCC. CCK-8, colony formation, EdU, wound healing, transwell, and flow cytometry assays were used to assess cell proliferation, migration, invasion, and cell cycle. Expressions of cell cycle proteins and ferroptosis biomarkers were detected by Western blot. The levels of Fe, ROS, MDA, SOD, and GSH in cells were detected by assay kits. Fluorescent probe was used to monitor the intracellular lipid peroxidation level. The binding of APEX1 and amyloid precursor protein (APP) was validated by Co-IP. The expressions of p53/xCT pathway proteins were examined by Western blot.
The results showed that APEX1 was highly expressed in ccRCC tissues and positively correlated with poor prognosis. Silencing of APEX1 inhibited the proliferation, invasion, and migration of Caki-1 cells and induced cell cycle arrest. This silencing also led to increased levels of intracellular Fe, lipid peroxidation, and ROS, thereby inducing cell ferroptosis. APEX1 could bind to APP, and their expressions were negatively correlated. Silencing of APP reversed the inhibition effects of APEX1 silencing on proliferation, invasion, migration, and cell cycle in Caki-1 cells. Moreover, silencing of APEX1 up-regulated the p53/xCT signaling by binding to APP, thereby promoting ferroptosis.
In summary, silencing of APEX1 promotes ferroptosis and inhibits the malignant progression of ccRCC, potentially through APP-mediated activation of p53/AKT signaling, providing a novel therapeutic strategy for ccRCC treatment.
脱嘌呤/脱嘧啶内切脱氧核糖核酸酶1（APEX1）参与调节多种癌细胞的增殖、侵袭、迁移及其他恶性进展。然而，其在透明细胞肾细胞癌（ccRCC）中的作用机制仍不清楚。
利用UALCAN数据库预测APEX1在ccRCC中的表达。采用CCK-8、集落形成、EdU、伤口愈合、Transwell和流式细胞术检测法评估细胞增殖、迁移、侵袭及细胞周期。通过蛋白质免疫印迹法检测细胞周期蛋白和铁死亡生物标志物的表达。使用检测试剂盒检测细胞中Fe、ROS、MDA、SOD和GSH的水平。用荧光探针监测细胞内脂质过氧化水平。通过免疫共沉淀法验证APEX1与淀粉样前体蛋白（APP）的结合。通过蛋白质免疫印迹法检测p53/xCT信号通路蛋白的表达。
结果显示，APEX1在ccRCC组织中高表达，且与不良预后呈正相关。沉默APEX1可抑制Caki-1细胞的增殖、侵袭和迁移，并诱导细胞周期停滞。这种沉默还导致细胞内Fe、脂质过氧化和ROS水平升高，从而诱导细胞铁死亡。APEX1可与APP结合，且它们的表达呈负相关。沉默APP可逆转APEX1沉默对Caki-1细胞增殖、侵袭、迁移和细胞周期的抑制作用。此外，沉默APEX1通过与APP结合上调p53/xCT信号，从而促进铁死亡。
综上所述，沉默APEX1可促进铁死亡并抑制ccRCC的恶性进展，可能是通过APP介导的p53/AKT信号激活实现的，为ccRCC治疗提供了一种新的治疗策略。
