SMURF2通过调节RACK1/AKT/mTOR信号通路抑制卵巢癌的自噬和生长。

SMURF2 Inhibits Autophagy and Growth in Ovarian Cancer by Regulating the RACK1/AKT/mTOR Pathway.

作者信息

Wu Lei, Xiao Ziyi, Zhang Siyue, Guo Li, Liu Xiaojian, Zhang Lihua, Xu Jingjing, Lv Mengmeng, Wang Jinhua

机构信息

Department of Gynecologic Oncology, Cancer Hospital Affiliated to Nanjing Medical University, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, Nanjing, China.

The First Affiliated Hospital of Baotou Medical College, Inner Mongolia University of Science and Technology, Baotou, Inner Mongolia, China.

出版信息

Am J Reprod Immunol. 2025 Aug;94(2):e70140. doi: 10.1111/aji.70140.

DOI:10.1111/aji.70140

PMID:40824172

Abstract

BACKGROUND

Ovarian cancer (OC) is a common malignancy characterized by disseminated peritoneal metastases. Smad ubiquitin regulatory factor 2 (SMURF2) is involved in OC progression by stabilizing receptor for activated C kinase 1 (RACK1). However, the functions and mechanisms of action of SMURF2 in OC remain unclear. This biological function of SMURF2 in OC and its potential mechanisms of action were investigated in this study.

METHODS

The expression of SMURF2 in ovarian tumor tissues, patient serum, and OC cell lines was determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and/or western blotting. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, flow cytometry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) were used for detecting cell proliferation and apoptosis. Autophagosomes in SKOV3 cells were observed using transmission electron microscopy. Immunohistochemistry and RT-qPCR were performed to evaluate SMURF2 expression. The levels of proteins related to autophagy and RACK1 were measured using western blotting and RT-qPCR, respectively. Western blotting was performed to assess the expression of AKT/mTOR pathway-related proteins.

RESULTS

SMURF2 was underexpressed in OC tissues and cell lines compared with that in adjacent normal tissues or normal ovarian epithelial cells. RT-qPCR results suggested that SMURF2 was downregulated in the serum of patients with OC. SMURF2 overexpression inhibited SKOV3 cell growth and autophagy, and induced apoptosis both in vitro and in vivo. Moreover, SMURF2 overexpression suppressed RACK1 expression in SKOV3 cells. The AKT/mTOR pathway was activated by SMURF2 overexpression in SKOV3, and OC cells and tissues.

CONCLUSIONS

SMURF2 plays a key role in OC by inhibiting cell autophagy and growth via activation of the RACK1/AKT/mTOR pathway, which might potentially be a new biomarker for OC diagnosis and therapy.

摘要

背景

卵巢癌（OC）是一种常见的恶性肿瘤，其特征为腹膜播散转移。Smad泛素调节因子2（SMURF2）通过稳定活化C激酶1受体（RACK1）参与OC进展。然而，SMURF2在OC中的功能及作用机制仍不清楚。本研究对SMURF2在OC中的这种生物学功能及其潜在作用机制进行了研究。

方法

采用逆转录-定量聚合酶链反应（RT-qPCR）和/或蛋白质印迹法检测SMURF2在卵巢肿瘤组织、患者血清及OC细胞系中的表达。采用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四唑溴盐（MTT）法、流式细胞术和末端脱氧核苷酸转移酶dUTP缺口末端标记法（TUNEL）检测细胞增殖和凋亡。用透射电子显微镜观察SKOV3细胞中的自噬体。进行免疫组织化学和RT-qPCR以评估SMURF2表达。分别用蛋白质印迹法和RT-qPCR检测自噬相关蛋白和RACK1的水平。采用蛋白质印迹法评估AKT/mTOR通路相关蛋白的表达。

结果

与相邻正常组织或正常卵巢上皮细胞相比，SMURF2在OC组织和细胞系中表达下调。RT-qPCR结果表明，OC患者血清中SMURF2表达下调。SMURF2过表达在体外和体内均抑制SKOV3细胞生长和自噬，并诱导细胞凋亡。此外，SMURF2过表达抑制SKOV3细胞中RACK1表达。在SKOV3、OC细胞和组织中，SMURF2过表达激活AKT/mTOR通路。