Zhou Jianping, Wu Lulu, Li Weiling, Xu Xiao, Ju Feng, Yu Shao, Guo Jianfeng, Li Gang, Shi Jun, Zhou Sujun
Department of Gastrointestinal Surgery, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, People's Republic of China.
Department of Obstetrics and Gynecology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, People's Republic of China.
Onco Targets Ther. 2020 Aug 21;13:8413-8425. doi: 10.2147/OTT.S257151. eCollection 2020.
Although several long non-coding RNAs (lncRNAs) have been found to be involved in gastric cancer tumorigenesis, the more comprehensive contributions of lncRNAs to gastric cancer require further investigation. Here, we identify a cytoplasmic lncRNA, LINC01485, which promotes tumor growth and migration in gastric cancer.
Microarray and computational analysis were utilized to identify differential expression in LINC01485 and EGFR. Real-time PCR and Western blotting assays were used to confirm the expression of LINC01485 and EGFR in gastric cancer cells. Cell proliferation, wound-healing and transwell assays were performed to measure cell growth, migration and invasion. Immunoprecipitation, RNA pull-down, and RNA fluorescence in situ hybridization (RNA-FISH) assays were used to test the interaction of c-Cbl with LINC01485 and EGFR. Furthermore, tumor xenograft in nude mice was performed to test tumor growth in vivo.
LINC01485 was upregulated and associated with tumor size, lymphatic metastasis and advanced pathological stage in gastric cancer. LINC01485 promoted gastric cancer cell proliferation, migration and invasion in vitro and in vivo. Furthermore, LINC01485 levels were positively correlated with EGFR expression in gastric cancer tissues and significantly increased the expression and phosphorylation (Tyr1045) of EGFR in gastric cancer cells. Mechanistically, LINC01485 competes with c-Cbl for binding to phosphorylated Tyr1045 site of EGFR, thus interfering with c-Cbl-mediated ubiquitination and subsequent degradation of EGFR.
LINC01485 promoted EGFR stabilization and activation of EGFR/Akt signaling in gastric cancer. Our findings illustrate the diversity of cytoplasmic lncRNAs in signal transduction and highlight the important roles of lncRNAs in gastric cancer.
尽管已发现几种长链非编码RNA（lncRNA）参与胃癌的肿瘤发生过程，但lncRNA对胃癌更全面的作用仍需进一步研究。在此，我们鉴定出一种细胞质lncRNA，即LINC01485，它可促进胃癌的肿瘤生长和迁移。
利用微阵列和计算分析来鉴定LINC01485和表皮生长因子受体（EGFR）的差异表达。采用实时定量聚合酶链反应（Real-time PCR）和蛋白质免疫印迹法（Western blotting）检测LINC01485和EGFR在胃癌细胞中的表达。进行细胞增殖、伤口愈合和Transwell实验以检测细胞生长、迁移和侵袭能力。采用免疫沉淀、RNA下拉实验以及RNA荧光原位杂交（RNA-FISH）实验检测衔接蛋白Cbl（c-Cbl）与LINC01485和EGFR的相互作用。此外，通过裸鼠肿瘤异种移植实验检测体内肿瘤生长情况。
LINC01485在胃癌中表达上调，且与肿瘤大小、淋巴转移及病理分期相关。LINC01485在体外和体内均能促进胃癌细胞的增殖、迁移和侵袭。此外，胃癌组织中LINC01485水平与EGFR表达呈正相关，并且显著增加了胃癌细胞中EGFR的表达及磷酸化水平（酪氨酸1045位点）。机制上，LINC01485与c-Cbl竞争结合EGFR的磷酸化酪氨酸1045位点，从而干扰c-Cbl介导的泛素化及随后的EGFR降解。
LINC01485促进胃癌中EGFR的稳定性及EGFR/Akt信号通路的激活。我们的研究结果阐明了细胞质lncRNA在信号转导中的多样性，并突出了lncRNA在胃癌中的重要作用。
