Miao Fang, Zhang Xueshan, Cao Yanning, Wang Yue, Zhang Xiaoshu
School of Basic Medical Sciences, Binzhou Medical University, 346 Guanhai Road, Yantai, Shandong, People's Republic of China.
BMC Cancer. 2017 Dec 11;17(1):838. doi: 10.1186/s12885-017-3843-y.
The role of Spalt-like gene-2 (SALL2) in tumorigenesis remains incompletely elucidated. This study investigated the effects of SALL2 on human ovarian carcinoma (OC) A2780 cells and the probable mechanism.
Expression of SALL2 in human OC cell lines were detected by reverse transcription PCR (RT-PCR) and Western blot analysis. A2780 cells were transfected with small-interfering ribonucleic acid (siRNA) to silence SALL2. SALL2 expression was detected by RT-PCR, Western blot analysis and immunofluorescence assay. Cell proliferation was measured by CCK-8 assay and flow cytometry (FCM). Apoptosis was measured by FCM. Cell migration was detected by real-time cell analysis. Cell invasion was detected by transwell assay. mRNA expression of p21 was detected by quantitative real-time PCR. Western blot analysis was used to determine the expression of matrix metalloproteinase (MMP)2, MMP9, protein kinase B (PKB, also called Akt), and phosphorylated-Akt (p-Akt).
SALL2 was expressed in six OC cell lines, and the expression was the highest in A2780 cells. Compared with that in the Scramble group, SALL2 expression in A2780 was downregulated after transfection with siRNA-2 and siRNA-3 for 48 h. Compared with that in the Scramble group, proliferation of A2780 cells in the siRNA-2 group increased after transfection for 24, 48 and 72 h. In the siRNA-2 group, the proportion of A2780 cells decreased in the G0/G1 phase, and cell apoptosis decreased after transfection for 48 h. Compared with that in the Scramble group, the cell migration and invasion abilities of A2780 cells increased. Compared with that in the Scramble group, p21 mRNA expression in A2780 cells decreased after transfection with siRNA2. When SALL2 was silenced, the expression of MMP2/9 and p-Akt in A2780 cells increased. Furthermore, the PI3K inhibitor LY294002 could effectively reversed SALL2 siRNA-induced phosphorylation of Akt, migration and invasion of A2780 cells.
Transient silencing of SALL2 promotes cell proliferation, migration, and invasion, and inhibits apoptosis of A2780 cells. In SALL2 siRNA-silenced cells, p21 expression was decreased. SALL2 knockdown by siRNA induces the migration and invasion of A2780 cells; this phenomenon is possibly associated with the increased expression of MMP2/9 and the activation of the PI3K/Akt signalling pathway.
锌指样基因2（SALL2）在肿瘤发生中的作用尚未完全阐明。本研究探讨SALL2对人卵巢癌（OC）A2780细胞的影响及其可能机制。
采用逆转录聚合酶链反应（RT-PCR）和蛋白质印迹分析检测人OC细胞系中SALL2的表达。用小干扰核糖核酸（siRNA）转染A2780细胞以沉默SALL2。通过RT-PCR、蛋白质印迹分析和免疫荧光测定法检测SALL2表达。采用细胞计数试剂盒-8（CCK-8）法和流式细胞术（FCM）检测细胞增殖。通过FCM检测细胞凋亡。采用实时细胞分析检测细胞迁移。采用Transwell实验检测细胞侵袭。通过定量实时PCR检测p21的mRNA表达。采用蛋白质印迹分析确定基质金属蛋白酶（MMP）2、MMP9、蛋白激酶B（PKB，也称为Akt）和磷酸化Akt（p-Akt）的表达。
SALL2在6种OC细胞系中均有表达，在A2780细胞中表达最高。与对照组相比，用siRNA-2和siRNA-3转染A2780细胞48小时后，SALL2表达下调。与对照组相比，转染siRNA-2组的A2780细胞在转染24、48和72小时后增殖增加。在siRNA-2组中，A2780细胞在G0/G1期的比例下降，转染48小时后细胞凋亡减少。与对照组相比，A2780细胞的迁移和侵袭能力增强。与对照组相比，用siRNA2转染后A2780细胞中p21 mRNA表达下降。当SALL2沉默时，A2780细胞中MMP2/9和p-Akt的表达增加。此外，PI3K抑制剂LY294002可有效逆转SALL2 siRNA诱导的Akt磷酸化、A2780细胞的迁移和侵袭。
短暂沉默SALL2可促进A2780细胞增殖、迁移和侵袭，并抑制其凋亡。在SALL2 siRNA沉默的细胞中，p21表达降低。siRNA敲低SALL2可诱导A2780细胞的迁移和侵袭；这种现象可能与MMP2/9表达增加和PI3K/Akt信号通路激活有关。
