PRL-1介导HBV相关肝细胞肝癌表皮间质转化的机制研究

HBV infection is the most common cause of primary hepatocellular carcinoma(HCC) in China.We utilized high-resolution SNP-CHIP techique to screen copy number alterations (CNAs) of the whole genome of 60 HBV positive HCC samples and found that PRL-1 copy number amplified in 7 cases;expression level of PRL-1 mRNA in HCC tissue was significantly higher than that in paracancerous tissue,indicating that PRL-1 may play important role in the occurrence and development of HBV related HCC.Our preliminary experiment data showed PRL-1 promoted cell proliferation, migration and invasion,and induced epithelial mesenchymal transition(EMT) of liver cancer cells.Our previous study and others'data displayed PRL-3 targeted PTEN and promoted EMT of colon cancer cells through PI3K/AKT pathway;both PRL-1 and PRL-3 belong to the same PRLs family and are highly homologous(79%).On basis of previous work,we proposed the hypothesis that PRL-1 induces EMT of liver cancer cells through PI3K/AKT pathway.In addition,we also found HBx upregulated PRL-1 expression in HCC,and promoted EMT of liver cancer cells.Above all,we speculate PRL-1 can mediate HBx promoting HCC cell EMT.Our group will further explore the mechanism of PRL-1 inducing EMT of HCC cells and its effect on tumor metastasis by in vitro and in vivo experiments, and investigate its clinical significance.

乙肝感染是我国肝细胞肝癌（以下简称肝癌）最常见病因。我们利用SNP芯片技术扫描了60例乙肝阳性肝癌样本全基因组，发现有7例存在PRL-1拷贝数扩增，且肝癌组织其mRNA表达水平明显高于癌旁组织，提示PRL-1可能在乙肝阳性肝癌发病机制中发挥重要作用。预实验结果显示PRL-1促进肝癌细胞增殖、迁移和侵袭，并诱导肝癌细胞EMT。我们及其他的研究显示PRL-3可靶向PTEN并通过PI3K/AKT通路促进结肠癌细胞EMT；PRL-1与PRL-3同属PRLs家族且79%同源。结合前期基础，我们提出了PRL-1通过PI3K/AKT通路诱导肝癌细胞EMT的假设。另外我们还发现HBx能上调肝癌细胞PRL-1的表达，且HBx也能促进肝癌细胞EMT。综上，我们推测PRL-1可介导HBx促肝癌细胞EMT。本研究将通过体内外试验研究PRL-1诱导肝癌EMT的机制及其对肿瘤转移的作用，并利用临床标本探讨其临床意义。

HBx蛋白是HBV引起肝癌的重要致癌蛋白，但其致癌机制仍未完全阐明。PRL-1亦称PTP4a1，属于蛋白酪氨酸磷酸酶（PTPs）大家族中的一员，其在肝癌中的作用仍未明确。本项目的预实验显示PRL-1可促进肝癌细胞的迁移、侵袭等恶性生物学行为，且PRL-1在肝癌中可受HBx调控。为了进一步证实上述现象，本项目的在执行过程中主要探讨了1.PRL-1促肝癌迁移与侵袭的具体机制；2.HBx调控PRL-1的具体机制。此外，我们的还探讨了HBx在肝癌中促癌的机制。在现阶段，我们的研究主要发现了：1. PRL-1通过PI3K/AKT/GSK-3β通路促进Snail表达，促进肝癌细胞的迁移和侵袭；2. HBx是介导细胞对硼替佐米耐受的重要分子，硼替佐米通过泛素化/蛋白酶通路调控HBx蛋白的表达，进而使Raf和ERK磷酸化增加，而PD98059通过抑制MAPK通路，与硼替佐米协同抑制细胞生长；3. 筛选并证实lncRNA WEE2-AS1可促进肝癌细胞增殖、迁移与侵袭，初步发现HBx可激活lncRNA WEE2-AS1启动子。这些发现为阐明PRL-1的促癌机制，以及进一步完善HBx蛋白促进肝癌发生发展的机制提供实验证据。