title: A miR-200b/200c/429-binding site polymorphism in the 3' untranslated region of the AP-2α gene is associated with cisplatin resistance.
abstract: The transcription factor AP-2α functions as a tumor suppressor by regulating various genes that are involved in cell proliferation and apoptosis. Chemotherapeutic drugs including cisplatin induce post-transcriptionally endogenous AP-2α, which contributes to chemosensitivity by enhancing therapy-induced apoptosis. microRNAs (miRNAs) miR-200b, miR-200c and miR-429 (miR-200b/200c/429) are up-regulated in endometrial and esophageal cancers, and their overexpression correlates with resistance to cisplatin treatment. Using computational programs, we predicted that the 3' untranslated region (UTR) of AP-2α gene contains a potential miRNA response element (MRE) for the miR-200b/200c/429 family, and the single nucleotide polymorphism (SNP) site rs1045385 (A or C allele) resided within the predicted MRE. Luciferase assays and Western blot analysis demonstrated that the miR-200b/200c/429 family recognized the MRE in the 3' UTR of AP-2α gene and negatively regulated the expression of endogenous AP-2α proteins. SNP rs1045385 A>C variation enhanced AP-2α expression by disrupting the binding of the miR-200b/200c/429 family to the 3' UTR of AP-2α. The effects of the two polymorphic variants on cisplatin sensitivity were determined by clonogenic assay. The overexpression of AP-2α with mutant 3' UTR (C allele) in the endometrial cancer cell line HEC-1A, which has high levels of endogenous miR-200b/200c/429 and low levels of AP-2α protein, significantly increased cisplatin sensitivity, but overexpression of A allele of AP-2α has no significant effects, compared with mock transfection. We concluded that miR-200b/200c/429 induced cisplatin resistance by repressing AP-2α expression in endometrial cancer cells. The SNP (rs1045385) A>C variation decreased the binding of miR-200b/200c/429 to the 3' UTR of AP-2α, which upregulated AP-2α protein expression and increased cisplatin sensitivity. Our results suggest that SNP (rs1045385) may be a potential prognostic marker for cisplatin treatment.
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wu
authors.forename: Yuzhong
authors.initials: Y
authors.lastname: Xiao
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ding
authors.forename: Yiming
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Peng
authors.initials: P
authors.lastname: Ren
authors.forename: Chang
authors.initials: C
authors.lastname: Zhou
authors.forename: Jianlin
authors.initials: J
authors.lastname: Zhou
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D050656:Transcription Factor AP-2 / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C533896:MIRN200 microRNA, human; C546363:MIRN429 microRNA, human; D035683:MicroRNAs; D050656:Transcription Factor AP-2; D002945:Cisplatin