Fan Feng1, Qiyu Jiang2, Shuang Cao3, Yu Cao4, Ruisheng Li2, Lijun Shen5, Hua Zhu6, Tao Wang7, Lijun Sun8, Erguang Liang7, Huiwei Sun2, Yantao Chai2, Xiaojuan Li2, Genyan Liu3, Ruichang Yang2, Zhi Yang4, Yongping Yang9, Shaojie Xin10, Bo-An Li11. 1. Center for Clinical Laboratory, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China; Liver Failure Treatment and Research Center, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. 2. Research Center for Clinical and Translational Medicine, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. 3. Hubei Key Laboratory of Novel Chemical Reactor and Green Chemical Technology, Wuhan Institute of Technology, Wuhan 430073, PR China. 4. Department of Immunology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA. 5. First Liver Cirrhosis Diagnosis and Treatment Center, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. 6. Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Nuclear Medicine, Peking University Cancer Hospital & Institute, Beijing 100142, PR China. 7. Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing 100850, PR China. 8. Center for Clinical Laboratory, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. 9. Center of Therapeutic Research for Hepatocellular Carcinoma, The 302nd Hospital, Beijing 100039, PR China. Electronic address: yongpingyang@hotmail.com. 10. Liver Failure Treatment and Research Center, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. Electronic address: xinshaojie302@163.com. 11. Center for Clinical Laboratory, The 302nd Hospital of Chinese PLA, Beijing 100039, PR China. Electronic address: lba@263.net.
Abstract
BACKGROUND: Kinase inhibitor sorafenib is the most widely used drug for advanced HCC clinical treatment nowadays. However, sorafenib administration is only effective for a small portion of HCC patients, and the majority develop sorafenib-resistance during treatment. Thus, it is urgent to discover the endogenous mechanism and identify new pharmaceutical targets of sorafenib-resistance. METHODS: Pregnane X receptor (PXR) was detected by immunohistochemistry and quantitative PCR. GST-pull down and LC-MS/MS was used to detect the interaction of PXR and Sorafenib. To test the properties of HCC tumor growth and metastasis, in vivo tumor explant model, FACS, trans-well assay, cell-survival inhibitory assay and Western blot were performed. In terms of mechanistic study, additional assays such as ChIP and luciferase reporter gene assay were applied. RESULTS: In the present work, we found high PXR level in clinical specimens is related to the poor prognosis of Sorafenib treated patients. By the mechanistic studies, we show that sorafenib binds to PXR and activates PXR pathway, and by which HCC cells develop sorafenib-resistance via activating. Moreover, PXR overexpression helps HCC cells to persist to sorafenib treatment. CONCLUSION: This study reports the endogenous sorafenib-resistance mechanism in HCC cells, which offers an opportunity to design new therapeutic approaches for HCC treatment. GENERAL SIGNIFICANCE: PXR mediates sorafenib-resistance in HCC cells and targeting PXR can be a useful approach to facilitate HCC treatment.
BACKGROUND: Kinase inhibitor sorafenib is the most widely used drug for advanced HCC clinical treatment nowadays. However, sorafenib administration is only effective for a small portion of HCC patients, and the majority develop sorafenib-resistance during treatment. Thus, it is urgent to discover the endogenous mechanism and identify new pharmaceutical targets of sorafenib-resistance. METHODS:Pregnane X receptor (PXR) was detected by immunohistochemistry and quantitative PCR. GST-pull down and LC-MS/MS was used to detect the interaction of PXR and Sorafenib. To test the properties of HCC tumor growth and metastasis, in vivo tumor explant model, FACS, trans-well assay, cell-survival inhibitory assay and Western blot were performed. In terms of mechanistic study, additional assays such as ChIP and luciferase reporter gene assay were applied. RESULTS: In the present work, we found high PXR level in clinical specimens is related to the poor prognosis of Sorafenib treated patients. By the mechanistic studies, we show that sorafenib binds to PXR and activates PXR pathway, and by which HCC cells develop sorafenib-resistance via activating. Moreover, PXR overexpression helps HCC cells to persist to sorafenib treatment. CONCLUSION: This study reports the endogenous sorafenib-resistance mechanism in HCC cells, which offers an opportunity to design new therapeutic approaches for HCC treatment. GENERAL SIGNIFICANCE: PXR mediates sorafenib-resistance in HCC cells and targeting PXR can be a useful approach to facilitate HCC treatment.