PROX1上调LncRNA-LIFR-AS1促进肝细胞癌恶性潜能的作用及其机制研究

Abnormal expression of Long non-coding RNA (LncRNA) is closely associated with the degree of hepatocellular carcinoma (HCC) malignant, but its molecular mechanism remains unclear. We previously found that PROX1 protein high expression of liver tumor resection patient were easier to recur, short survival , in vivo assays confirmed that PROX1 promotes HCC growth and metastasis, but the molecular mechanism of PROX1 regulation HCC malignant potential remains unclear. We identified a series of LncRNA regulated by PROX1 via transcriptome sequencing. After screening and functional verification found that PROX1 up-regulates LncRNA-LIFR-AS1, LncRNA-LIFR-AS1 promotes the HCC growth and metastasis. Depth study found that LncRNA-LIFR-AS1 increases beta-catenin protein levels and promotes its nuclear translocation. This paper intends to study the molecular mechanisms of LncRNA-LIFR-AS1 regulation of beta-catenin expression and promotion its nuclear translocation, In vitro, in vivo assays and clinical specimens clarify that function and mechanism of PROX1-LncRNA-LIFR-AS1-beta-catenin function axis in HCC malignant transformation, To of providing the theoretical basis and intervention targets for developing more effective means of treatment of HCC.

长链非编码RNA（LncRNA）的异常表达与肝癌的恶性程度相关，但其作用机制不清楚。我们前期发现肝癌切除术后PROX1蛋白高表达者易复发、生存期短，体内实验证实PROX1促进肝癌的生长和转移，但PROX1调控肝癌恶性潜能的分子机制仍不明确。前期通过转录组测序发现了受到PROX1调控的一系列LncRNA。经筛选与功能验证发现LncRNA-LIFR-AS1受到PROX1的正向调控，并且能够促进肝癌生长及转移。深入研究发现LncRNA-LIFR-AS1上调beta-catenin的蛋白质水平并且促进其核转位。本课题拟研究LncRNA-LIFR-AS1调控beta-catenin表达及促进其核转位的分子机制，通过体外、体内实验及临床标本阐明PROX1-LncRNA-LIFR-AS1-beta-catenin功能轴在肝癌恶性转化中的作用及分子机制，为研发更有效的肝癌治疗手段提供理论基础和干预靶点。

转移复发是肝癌患者死亡的首要原因，而新生血管生成在肝癌转移过程中发挥重要作用，因此，阻断血管生成已成为肿瘤治疗特别是抗转移干预的一项重要途径。本课题我们系统研究PROX1调控肝癌恶性潜能的分子机制，研究发现PROX1全新的生物学功能-促肝癌血管生成因子，临床肝癌病人中首先发现高表达PROX1的患者中微血管密度和IL-8水平明显上调，体内外实验也证实PROX1可以显著促进肝癌的血管生成能力, 机制上我们通过同位素标记技术（SILAC）和蛋白质谱等手段，发现PROX1可以通过募集泛素特异性蛋白酶7（ubiquitin specific protease 7, USP7）结合到NF-κB/p65蛋白上抑制其泛素化水平，从而促进NF-κB/p65蛋白的稳定性及其细胞核定位，继而通过表观遗传学修饰，选择性地激活 IL-8 的表达从而促进肝癌的疾病进展过程，更有意义的是，我们发现利用IL-8单抗可以显著抑制高表达PROX1肝癌的疾病进展过程，并且提高高表达PROX1肝癌模型小鼠的总体生存时间。 这项研究结果为临床抗肝癌转移复发治疗提供了新的途径，并为肝癌转移复发的个体化精准防治提供了精准分型方案。