Wu Zhiqiang, Wang Chunmeng, Chen Yong, Sun Zhengwang, Yan Wangjun
Department of Musculoskeletal Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, People's Republic of China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, People's Republic of China.
Onco Targets Ther. 2020 Feb 26;13:1737-1749. doi: 10.2147/OTT.S225602. eCollection 2020.
BACKGROUND/PURPOSE: Osteosarcoma (OS), a primary bone malignancy, is characterized by a high rate of metastasis. It has been found that Sushi repeat containing protein X-linked 2 (SRPX2) is involved in tumor cell proliferation, adhesion, invasion and migration. The current work aimed to explore the effect of SRPX2 on OS cell invasion and proliferation.
Immunohistochemistry (IHC), Western blotting and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the expression of the associated protein in OS tissues and cell lines. Cell counting kit-8 (CCK8), transwell and colony formation assays were used to determine cell viability, invasion, and proliferation, respectively. The in vivo tumorigenic ability of SRPX2 gene was determined using nude mouse tumorigenesis test.
SRPX2 knockdown suppressed the viability, while SRPX2 overexpression increased the invasion and colony formation ability of the cells in vitro. In vivo experiments demonstrated that SRPX2 knockdown inhibited tumor growth and invasion as evidenced by decreased Ki67 and N-cadherin levels, and increased E-cadherin level. Downregulation of SRPX2 increased YAP phosphorylation resulting in reduced nuclear translocation to activate Hippo signaling pathway. The promotion of cell viability, colony-forming ability, and invasion, and the inhibition of CTGF, Cyr61, and Birc5 levels promoted by SRPX2 overexpression were reversed by YAP inhibition.
SRPX2 increased cell proliferation and invasion in osteosarcoma by activating Hippo signaling pathway.
背景/目的：骨肉瘤（OS）是一种原发性骨恶性肿瘤，其特点是转移率高。已发现含寿司重复序列的X连锁蛋白2（SRPX2）参与肿瘤细胞的增殖、黏附、侵袭和迁移。当前研究旨在探讨SRPX2对骨肉瘤细胞侵袭和增殖的影响。
采用免疫组织化学（IHC）、蛋白质免疫印迹法和逆转录-聚合酶链反应（RT-PCR）检测骨肉瘤组织和细胞系中相关蛋白的表达。分别使用细胞计数试剂盒-8（CCK8）、Transwell实验和集落形成实验来测定细胞活力、侵袭能力和增殖能力。使用裸鼠成瘤实验测定SRPX2基因的体内致瘤能力。
敲低SRPX2可抑制细胞活力，而过表达SRPX2可增强细胞的侵袭能力和集落形成能力。体内实验表明，敲低SRPX2可抑制肿瘤生长和侵袭，表现为Ki67和N-钙黏蛋白水平降低，E-钙黏蛋白水平升高。SRPX2的下调增加了YAP的磷酸化，导致其核转位减少，从而激活Hippo信号通路。YAP抑制可逆转SRPX2过表达所促进的细胞活力、集落形成能力和侵袭能力，并抑制CTGF、Cyr61和Birc5水平。
SRPX2通过激活Hippo信号通路增加骨肉瘤细胞的增殖和侵袭能力。
