Li Bo-Pei, Mao Yuan-Tian, Wang Zhen, Chen Ye-Yang, Wang Ye, Zhai Chong-Yu, Shi Bo, Liu Si-Yu, Liu Jin-Lu, Chen Jun-Qiang
Department of Gastrointestinal Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Department of General Surgery, The First People's Hospital of Yulin, Yulin, China.
Cell Physiol Biochem. 2018;46(3):907-924. doi: 10.1159/000488822. Epub 2018 Apr 13.
BACKGROUND/AIMS: Chloride intracellular channel 1 (CLIC1), which is a member of the chloride channel protein family, is associated with various human tumors. Recent studies have shown that CLIC1 is involved in the occurrence and development of gastric cancer (GC). However, the exact mechanism remains unclear in GC.
Effects of CLIC1 on the progression of GC in vivo and in vitro and the potential underlying mechanisms have been investigated by analysing 54 patients with GC, as well as human gastric cell lines SGC-7901 and MGC-803, utilizing proteomics, RT-PCR, Western blotting, flow cytometry, Cell invasion and migration assays and xenograft tumor models.
Our study shows that CLIC1 knockdown by targeted-siRNA markedly inhibits GC cell invasion and migration and induces apoptosis in vitro. In total, 54 differentially expressed proteins were identified in GC cells SGC-7901 after CLIC1 silencing by isobaric tags for relative isotope labeled and absolute quantitation (iTRAQ) technology, including integrin α1 (ITGα1) and ITGα3. The expression levels of ITGα3, ITGαv, ITGβ1 and Bcl-2 mRNA and protein were decreased significantly in GC cells after CLIC1 knockdown; ITGα1 and Fas were upregulated, but the level of survivin was not significantly different. GC growth and metabolism were decreased in vivo after CLIC1 silencing, but apoptosis was markedly increased. Further study showed that the expression levels of ITGα3, ITGαv and ITGβ1, as well as AKT-phosphorylation, ERK-phosphorylation and p38-phosphorylation, were reduced in vivo after CLIC1 knockdown, while ITGα1 was upregulated.
We speculate that CLIC1 may play an important role in the progression of GC, and its mechanism may be related to the regulation of integrin family proteins, which leads to the sequential regulation of the PI3K/AKT, MAPK/ERK and MAPK/p38 pathways.
背景/目的：氯离子细胞内通道蛋白1（CLIC1）是氯离子通道蛋白家族成员之一，与多种人类肿瘤相关。近期研究表明，CLIC1参与胃癌（GC）的发生发展。然而，在胃癌中其确切机制仍不清楚。
通过分析54例胃癌患者以及人胃癌细胞系SGC-7901和MGC-803，利用蛋白质组学、逆转录-聚合酶链反应（RT-PCR）、蛋白质免疫印迹法、流式细胞术、细胞侵袭和迁移实验以及异种移植肿瘤模型，研究CLIC1对胃癌体内外进展的影响及其潜在机制。
我们的研究表明，靶向小干扰RNA（siRNA）敲低CLIC1可显著抑制胃癌细胞的侵袭和迁移，并在体外诱导细胞凋亡。采用相对和绝对定量同位素标记同量异位标签（iTRAQ）技术沉默CLIC1后，在胃癌细胞SGC-7901中总共鉴定出54种差异表达蛋白，包括整合素α1（ITGα1）和ITGα3。敲低CLIC1后，胃癌细胞中ITGα3、ITGαv、ITGβ1和Bcl-2的mRNA及蛋白表达水平显著降低；ITGα1和Fas上调，但生存素水平无显著差异。沉默CLIC1后，胃癌在体内的生长和代谢降低，但细胞凋亡明显增加。进一步研究表明，敲低CLIC1后，体内ITGα3、ITGαv和ITGβ1的表达水平以及AKT磷酸化、ERK磷酸化和p38磷酸化降低，而ITGα1上调。
我们推测CLIC1可能在胃癌进展中起重要作用，其机制可能与整合素家族蛋白的调节有关，进而导致PI3K/AKT、MAPK/ERK和MAPK/p38信号通路的相继调节。
