title: ZHX2 enhances the cytotoxicity of chemotherapeutic drugs in liver tumor cells by repressing MDR1 via interfering with NF-YA.
abstract: We previously reported the tumor suppressor function of Zinc-fingers and homeoboxes 2 (ZHX2) in hepatocellular carcinoma (HCC). Other studies indicate the association of increased ZHX2 expression with improved response to high dose chemotherapy in multiple myeloma. Here, we aim to test whether increased ZHX2 levels in HCC cells repress multidrug resistance 1(MDR1) expression resulting in increased sensitivity to chemotherapeutic drugs. We showed evidence that increased ZHX2 levels correlated with reduced MDR1 expression and enhanced the cytotoxicity of CDDP and ADM in different HCC cell lines. Consistently, elevated ZHX2 significantly reduced ADM efflux in HepG2 cells and greatly increased the CDDP-mediated suppression of liver tumor growth in vivo. Furthermore, immunohistochemical staining demonstrated the inverse correlation of ZHX2 and MDR1 expression in HCC tissues. Luciferase report assay showed that ZHX2 repressed the MDR1 promoter activity, while knockdown of NF-YA or mutating the NF-Y binding site eliminated this ZHX2-mediated repression of MDR1 transcription. Co-IP and ChIP assay further suggested that ZHX2 interacted with NF-YA and reduced NF-Y binding to the MDR1 promoter. Taken together, we clarify that ZHX2 represses NF-Y-mediated activation of MDR1 transcription and, in doing so, enhances the effects of chemotherapeutics in HCC cells both in vitro and in vivo.
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Hongxin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Xuetian
authors.initials: X
authors.lastname: Yue
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Lifen
authors.initials: L
authors.lastname: Gao
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liang
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Wenjiang
authors.initials: W
authors.lastname: Yan
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Shan
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Hualin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Microbiology, Immunology, & Molecular Genetics and Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, USA.
authors.forename: Brett T
authors.initials: BT
authors.lastname: Spear
authors.affiliation: Key Laboratory for Experimental Teratology of Ministry of Education and Department of Immunology, Shandong University School of Medicine, Jinan, Shandong, P.R. China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Ma
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000368:Aged; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D023081:CCAAT-Binding Factor / Q000235:genetics* / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002945:Cisplatin / Q000494:pharmacology; D005260:Female; D057809:HEK293 Cells; D056945:Hep G2 Cells; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D011485:Protein Binding; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D000970:Antineoplastic Agents; D023081:CCAAT-Binding Factor; D018398:Homeodomain Proteins; C492061:NFYA protein, human; D014157:Transcription Factors; C476826:ZHX2 protein, human; D002945:Cisplatin