IGF2BP1 overexpression promotes hepatocellular carcinoma (HCC) progression. Long non-coding RNA LIN28B-AS1 directly binds to IGF2BP1. In the present study, LIN28B-AS1 and IGF2BP1 expression and their potential functions in HCC cells were tested. Genetic strategies were applied to interfere their expression, and cell survival, proliferation and apoptosis were analyzed. We show that LIN28B-AS1 is expressed in established/primary human HCC cells and HCC tissues. RNA-immunoprecipitation (RIP) and RNA pull-down results confirmed that LIN28B-AS1 directly associated with IGF2BP1 protein in HCC cells. LIN28B-AS1 silencing (by targeted siRNAs) or knockout (KO, by CRISPR-Cas9 method) depleted IGF2BP1-dependent mRNAs (IGF2, Gli1, and Myc), inhibiting HCC cell growth, proliferation, migration, and invasion. Conversely, ectopic overexpression of LIN28B-AS1 upregulated IGF2BP1-dependent mRNAs and promoted HCC cell progression in vitro. Importantly, ectopic IGF2BP1 overexpression failed to rescue LIN28B-AS1-KO HepG2 cells. LIN28B-AS1 siRNA and overexpression were ineffective in IGF2BP1-KO HepG2 cells. In vivo, LIN28B-AS1 KO-HepG2 xenograft tumors grew significantly slower than the control tumors in the nude mice. Taken together, we conclude that LIN28B-AS1 associates with IGF2BP1 to promote human HCC cell progression in vitro and in vivo.

IGF2BP1 过表达促进肝细胞癌 (HCC) 进展。长链非编码 RNA LIN28B-AS1 直接与 IGF2BP1 结合。在本研究中，测试了 LIN28B-AS1 和 IGF2BP1 的表达及其在 HCC 细胞中的潜在功能。应用遗传策略来干扰它们的表达，并分析细胞存活、增殖和凋亡。我们表明 LIN28B-AS1 在已建立的/原代人类 HCC 细胞和 HCC 组织中表达。RNA 免疫沉淀 (RIP) 和 RNA 下拉结果证实 LIN28B-AS1 与 HCC 细胞中的 IGF2BP1 蛋白直接相关。LIN28B-AS1 沉默（通过靶向 siRNA）或敲除（KO，通过 CRISPR-Cas9 方法）耗尽了 IGF2BP1 依赖性 mRNA（IGF2、Gli1和Myc)，抑制 HCC 细胞生长、增殖、迁移和侵袭。相反，LIN28B-AS1 的异位过表达上调了 IGF2BP1 依赖性 mRNA，并促进了体外 HCC 细胞的进展。重要的是，异位 IGF2BP1 过表达未能挽救 LIN28B-AS1-KO HepG2 细胞。LIN28B-AS1 siRNA 和过表达在 IGF2BP1-KO HepG2 细胞中无效。在体内，LIN28B-AS1 KO-HepG2 异种移植肿瘤在裸鼠中的生长明显慢于对照肿瘤。总之，我们得出结论，LIN28B-AS1 与 IGF2BP1 结合以促进体外和体内人类 HCC 细胞的进展。