TCF12 promotes the tumorigenesis and metastasis of hepatocellular carcinoma via upregulation of CXCR4 expression
TCF12 promotes the tumorigenesis and metastasis of hepatocellular carcinoma via upregulation of CXCR4 expression
复制标题
TCF12通过上调CXCR4表达促进肝细胞癌的发生和转移
DOI：
10.7150/thno.34973
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发表时间：
2019-01-01
期刊：
影响因子：
12.4
通讯作者：
Li, Jinjun
中科院分区：
文献类型：
--
作者：
Yang, Jing;Zhang, Lili;Li, Jinjun
已知TCF 12参与细胞生长和分化的调节，已报道在各种恶性肿瘤的进展中作为癌基因或肿瘤抑制基因发挥作用。然而，其在肝细胞癌（HCC）中的作用及其分子机制尚不清楚。方法：通过慢病毒感染建立稳定异位表达或敲低TCF 12的肝癌细胞系。然后通过MTT法、集落形成、迁移、侵袭、HUVECs管腔形成实验以及原位异种移植模型研究TCF 12在肝癌细胞体内外的生物学功能。随后，利用RNA-Seq分析来探索TCF 12调控的靶基因。采用RT-qPCR、Western blotting、双荧光素酶报告基因分析、Ch-IP、CHIP-Seq和功能拯救实验等方法对TCF 12调控的靶基因进行了确认。采用RT-qPCR、western blot和免疫组织化学（IHC）检测TCF 12的表达水平，分析TCF 12与下游基因的相关性以及TCF 12在原发性肝癌中的临床意义。结果如下：我们的功能研究表明，TCF 12在人肝癌细胞中的稳定过表达增强了细胞的增殖，迁移和侵袭在体外和体内，而TCF 12的敲除表现出相反的效果。从机制上讲，CXCR 4是TCF 12的下游靶点，TCF 12直接与CXCR 4启动子结合以调节其表达。此外，CXCR 4及其配体CXCL 12通过激活MAPK/ERK和PI 3 K/AKT信号通路在TCF 12诱导的肿瘤进展中发挥关键作用。临床上，IHC分析显示TCF 12与HCC患者的不良生存率显著相关，并且原发性HCC组织中TCF 12表达与CXCR 4表达密切相关。结论：我们的研究结果首次表明TCF 12主要通过上调CXCR 4表达促进HCC的发生和进展，并且是HCC患者的预后指标。
TCF12, which is known to be involved in the regulation of cell growth and differentiation, has been reported to function as an oncogene or a tumor suppressor gene in the progression of various malignant tumors. However, its function and molecular mechanism in hepatocellular carcinoma (HCC) remain unclear. Methods: Stable ectopic TCF12 expression or knockdown in HCC cell lines was established by lentiviral infection. Then, MTT, colony formation, migration, invasion and HUVECs tube formation assays as well as an orthotopic xenograft model were used to investigate the biologic function of TCF12 in HCC cells in vitro and in vivo. Subsequently, RNA-Seq analysis was utilized to explore the target genes regulated by TCF12. RT-qPCR, western blotting, a dual-luciferase reporter assay, Ch-IP, CHIP-Seq and functional rescue experiments were used to confirm the target gene regulated by TCF12. Finally, RT-qPCR, western blot and immunohistochemical (IHC) staining were performed to detect the expression level of TCF12 and to analyze the correlation of TCF12 with downstream genes as well as the clinical significance of TCF12 in human primary HCC. Results: Our functional studies revealed that stable overexpression of TCF12 in human HCC cells enhanced cell proliferation, migration and invasion in vitro and in vivo, whereas knockdown of TCF12 showed opposing effects. Mechanistically, CXCR4 was a downstream target of TCF12, and TCF12 directly bound to the CXCR4 promoter to regulate its expression. Moreover, CXCR4, with its ligand CXCL12, played a critical role in tumor progression induced by TCF12 via activation of the MAPK/ERK and PI3K/AKT signaling pathways. Clinically, IHC analysis revealed that TCF12 was significantly associated with poor survival of HCC patients and that TCF12 expression was closely correlated with CXCR4 expression in primary HCC tissues. Conclusion: Our findings are the first to indicate that TCF12 could promote the tumorigenesis and progression of HCC mainly by upregulating CXCR4 expression and is a prognostic indicator for patients with HCC.