Xie Wei, Bao Zhongming, Yao Dan, Yang Yong
Department of General Surgery, Jurong Hospital Affiliated to Jiangsu University, Zhenjiang, Jiangsu, 212400, P.R. China.
Department of Hepatobiliary Surgery, Huai'an Fifth People's Hospital, Huaiyin, Jiangsu, 223300, P.R. China.
Cell Div. 2024 Sep 11;19(1):27. doi: 10.1186/s13008-024-00131-z.
T-cell leukemia homeobox protein 1 (TLX1) has been revealed as a hub transcription factor in leukemia, while its function in hepatocellular carcinoma (HCC) has not been well described. Here, we investigated the regulation and function of TLX1 in HCC.
TLX1 and its possible upstream and downstream molecules in HCC were identified using bioinformatics tools, which were then verified by RT-qPCR assay. CCK-8, wound healing, and Transwell invasion assays were performed to detect the effects of TLX1 knockdown on HCC cells. The interactions between TLX1 and trafficking protein particle complex subunit 9 (TRAPPC9) or Zinc finger protein 69 homolog B (ZFP69B) were further probed by ChIP and luciferase reporter assays. Rescue experiments were finally conducted in vitro and in vivo.
TLX1 was highly expressed in HCC cells, and the knockdown of TLX1 led to reduced malignant biological behavior of HCC cells. TLX1 bound to the promoter region of TRAPPC9, thereby promoting TRAPPC9 expression. Overexpression of TRAPPC9 attenuated the effect of TLX1 reduction on suppressing malignant behavior of HCC cells. ZFP69B was also highly expressed in HCC cells and bound to the promoter region of TLX1 to induce TLX1 expression. Knockdown of ZFP69B inhibited the viability and mobility of HCC cells in vitro and tumor growth in vivo, and overexpression of TLX1 rescued this inhibition.
These findings suggest that ZFP69B promotes the proliferation of HCC cells by directly upregulating the expression of TLX1 and the ensuing TRAPPC9.
T细胞白血病同源盒蛋白1（TLX1）已被揭示为白血病中的一个核心转录因子，但其在肝细胞癌（HCC）中的功能尚未得到充分描述。在此，我们研究了TLX1在HCC中的调控及功能。
使用生物信息学工具鉴定HCC中TLX1及其可能的上下游分子，随后通过RT-qPCR检测进行验证。进行CCK-8、伤口愈合和Transwell侵袭实验，以检测TLX1敲低对HCC细胞的影响。通过染色质免疫沉淀（ChIP）和荧光素酶报告基因实验进一步探究TLX1与转运蛋白颗粒复合体亚基9（TRAPPC9）或锌指蛋白69同源物B（ZFP69B）之间的相互作用。最后在体外和体内进行拯救实验。
TLX1在HCC细胞中高表达，敲低TLX1导致HCC细胞的恶性生物学行为降低。TLX1与TRAPPC9的启动子区域结合，从而促进TRAPPC9表达。TRAPPC9的过表达减弱了TLX1降低对抑制HCC细胞恶性行为的影响。ZFP69B在HCC细胞中也高表达，并与TLX1的启动子区域结合以诱导TLX1表达。敲低ZFP69B在体外抑制了HCC细胞的活力和迁移能力以及体内肿瘤生长，而TLX1的过表达挽救了这种抑制作用。
这些发现表明，ZFP69B通过直接上调TLX1及随后的TRAPPC9的表达来促进HCC细胞的增殖。
