Li Kun, Peng Yi-Fan, Guo Jing-Zhu, Li Mei, Zhang Yu, Chen Jing-Yi, Lin Ting-Ru, Yu Xin, Yu Wei-Dong
Department of Central Laboratory and Institute of Clinical Molecular Biology, Peking University People's Hospital, Beijing 100044, China.
Gastrointestinal Cancer Center, Unit III, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital and Institute, Beijing 100142, China.
World J Gastroenterol. 2021 Apr 21;27(15):1595-1615. doi: 10.3748/wjg.v27.i15.1595.
Expression of the full-length isoform of Abelson interactor 1 (ABI1), ABI1-p65, is increased in colorectal carcinoma (CRC) and is thought to be involved in one or more steps leading to tumor progression or metastasis. The ABI1 splice isoform-L (ABI1-SiL) has conserved WAVE2-binding and SH3 domains, lacks the homeo-domain homologous region, and is missing the majority of PxxP- and Pro-rich domains found in full-length ABI1-p65. Thus, ABI1-SiL domain structure suggests that the protein may regulate CRC cell morphology, adhesion, migration, and metastasis interactions with the WAVE2 complex pathway.
To investigate the potential role and underlying mechanisms associated with ABI1-SiL-mediated regulation of CRC.
ABI1-SiL mRNA expression in CC tissue and cell lines was measured using both qualitative reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR. A stably ABI1-SiL overexpressing SW480 cell model was constructed using Lipofectamine 2000, and cells selected with G418. Image J software, CCK8, and transwell assays were used to investigate SW480 cell surface area, proliferation, migration, and invasion. Immunoprecipitation, Western blot, and co-localization assays were performed to explore intermolecular interactions between ABI1-SiL, WAVE2, and ABI1-p65 proteins.
ABI1-SiL was expressed in normal colon tissue and was significantly decreased in CRC cell lines and tissues. Overexpression of ABI1-SiL in SW480 cells significantly increased the cell surface area and inhibited the adhesive and migration properties of the cells, but did not alter their invasive capacity. Similar to ABI1-p65, ABI1-SiL still binds WAVE2, and the ABI1-p65 isoform in SW480 cells. Furthermore, co-localization assays confirmed these intermolecular interactions.
These results support a model in which ABI1-SiL plays an anti-oncogenic role by competitively binding to WAVE2 and directly interacting with phosphorylated and non-phosphorylated ABI1-p65, functioning as a dominant-negative form of ABI1-p65.
在结直肠癌（CRC）中，阿贝尔森相互作用蛋白1（ABI1）的全长异构体ABI1-p65表达增加，被认为参与导致肿瘤进展或转移的一个或多个步骤。ABI1剪接异构体-L（ABI1-SiL）具有保守的WAVE2结合结构域和SH3结构域，缺乏同源结构域同源区域，并且缺失全长ABI1-p65中发现的大部分富含PxxP和脯氨酸的结构域。因此，ABI1-SiL的结构域结构表明该蛋白可能通过与WAVE2复合途径相互作用来调节CRC细胞的形态、黏附、迁移和转移。
研究ABI1-SiL介导的对CRC调节作用的潜在作用及潜在机制。
采用定性逆转录聚合酶链反应（RT-PCR）和实时定量RT-PCR检测CRC组织和细胞系中ABI1-SiL mRNA的表达。使用脂质体2000构建稳定过表达ABI1-SiL的SW480细胞模型，并用G418筛选细胞。使用Image J软件、CCK8和Transwell实验来研究SW480细胞的表面积、增殖、迁移和侵袭能力。进行免疫沉淀、蛋白质印迹和共定位实验以探索ABI1-SiL、WAVE2和ABI1-p65蛋白之间的分子间相互作用。
ABI1-SiL在正常结肠组织中表达，在CRC细胞系和组织中显著降低。SW480细胞中ABI1-SiL的过表达显著增加了细胞表面积，并抑制了细胞的黏附与迁移特性，但未改变其侵袭能力。与ABI1-p65类似，ABI1-SiL仍能结合WAVE2以及SW480细胞中的ABI1-p65异构体。此外，共定位实验证实了这些分子间相互作用。
这些结果支持这样一种模型，即ABI1-SiL通过竞争性结合WAVE2并直接与磷酸化和非磷酸化的ABI1-p65相互作用，发挥抗致癌作用，作为ABI1-p65的显性负性形式。
