Senior Department of Hepatology, the Fifth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, 100039, China.
Department of Emergency, the Fifth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, 100039, China.
Cell Death Dis. 2023 Jan 27;14(1):64. doi: 10.1038/s41419-022-05537-7.
The pregnane X receptor (PXR) is an important regulator of hepatocellular carcinoma cellular resistance to antitumor drugs. Activation of PXR was modulated by the co-regulators. The target protein for the Xenopus plus end-directed kinesin-like protein (Xklp2) known as TPX2 that was previously considered as a tubulin regulator, also functions as the regulator of some transcription factors and pro-oncogenes in human malignances. However, the actions of TPX2 on PXR and HCC cells are still unclear. In the present study, our results demonstrate that the high expression of endogenous mRNA level of TPX2 not only correlated with the poor prognosis of advanced HCC patients who received sorafenib treatment but also with expression of PXR's downstream genes, cyp3a4 and/or mdr-1. Results from luciferase and real-time polymerase chain reaction (qPCR) showed that TPX2 leads to enhancement of the transcription factor activation of PXR. Protein-protein interactions between PXR and TPX2 were identified using co-immunoprecipitation. Mechanically, overexpression of TPX2 led to enhancement of PXR recruitment to its downstream gene cyp3a4's promoter region (the PXRE region) or enhancer region (the XREM region). Treatment of HCC cells with paclitaxel, a microtubule promoter, led to enhancement of the effects of TPX2, whereas vincristine, a microtubule depolymerizing agent caused a decrease in TPX2-associated effects. TPX2 was found to cause acceleration of the metabolism or clearance of sorafenib, a typical tyrosine kinase inhibitor (TKI) in HCC cells and in turn led to the resistance to sorafenib by HCC cells. By establishing novel actions of TXP2 on PXR in HCC cells, the results indicate that TPX2 could be considered a promising therapeutic target to enhance HCC cells sensitivity to antitumor drugs.
妊娠相关 X 受体 (PXR) 是一种重要的调节因子,可调节肝癌细胞对抗肿瘤药物的耐药性。PXR 的激活受共调节剂调节。已知叉状头转录因子 P 家族 3 亚组 A(Foxp3)结合蛋白(Foxp3BP)是一种 Xenopus 末端定向的驱动蛋白样蛋白(Xklp2)的靶蛋白,也作为人类恶性肿瘤中一些转录因子和原癌基因的调节剂。然而,TPX2 对 PXR 和 HCC 细胞的作用尚不清楚。在本研究中,我们的结果表明,内源性 mRNA 水平的高表达不仅与接受索拉非尼治疗的晚期 HCC 患者的预后不良相关,而且与 PXR 的下游基因 cyp3a4 和/或 mdr-1 的表达相关。荧光素酶和实时聚合酶链反应 (qPCR) 的结果表明,TPX2 导致 PXR 转录因子激活增强。使用共免疫沉淀鉴定了 PXR 和 TPX2 之间的蛋白-蛋白相互作用。通过机制研究发现,过表达 TPX2 导致 PXR 募集到其下游基因 cyp3a4 的启动子区域 (PXRE 区域) 或增强子区域 (XREM 区域)。用紫杉醇处理 HCC 细胞,一种微管促进剂,增强了 TPX2 的作用,而长春新碱,一种微管解聚剂,导致与 TPX2 相关的作用减少。发现 TPX2 导致索拉非尼(一种 HCC 细胞中的典型酪氨酸激酶抑制剂 (TKI))的代谢或清除加速,从而导致 HCC 细胞对索拉非尼的耐药性。通过在 HCC 细胞中建立 TPX2 对 PXR 的新作用,结果表明 TPX2 可被认为是增强 HCC 细胞对抗肿瘤药物敏感性的有前途的治疗靶点。
Biochim Biophys Acta Gen Subj. 2018-1-31
Cell Commun Signal. 2020-7-28
Int J Mol Sci. 2025-8-20
Front Immunol. 2025-6-16
Cell Oncol (Dordr). 2025-8
BMC Med Genomics. 2025-4-28
BMC Complement Med Ther. 2025-1-27
Curr Cancer Drug Targets. 2022
Cell Death Dis. 2022-3-10
Acta Pharm Sin B. 2022-1