title: Alterations of microRNAs and their targets are associated with acquired resistance of MCF-7 breast cancer cells to cisplatin.
abstract: Cancer cells that develop resistance to chemotherapeutic agents are a major clinical obstacle in the successful treatment of breast cancer. Acquired cancer chemoresistance is a multifactorial phenomenon, involving various mechanisms and processes. Recent studies suggest that chemoresistance may be linked to drug-induced dysregulation of microRNA function. Furthermore, mounting evidence indicates the existence of similarities between drug-resistant and metastatic cancer cells in terms of resistance to apoptosis and enhanced invasiveness. We studied the role of miRNA alterations in the acquisition of cisplatin-resistant phenotype in MCF-7 human breast adenocarcinoma cells. We identified a total of 103 miRNAs that were overexpressed or underexpressed (46 upregulated and 57 downregulated) in MCF-7 cells resistant to cisplatin. These differentially expressed miRNAs are involved in the control of cell signaling, cell survival, DNA methylation and invasiveness. The most significantly dysregulated miRNAs were miR-146a, miR-10a, miR-221/222, miR-345, miR-200b and miR-200c. Furthermore, we demonstrated that miR-345 and miR-7 target the human multidrug resistance-associated protein 1. These results suggest that dysregulated miRNA expression may underlie the abnormal functioning of critical cellular processes associated with the cisplatin-resistant phenotype.
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA. igor.pogribny@fda.hhs.gov
authors.forename: Igor P
authors.initials: IP
authors.lastname: Pogribny
authors.forename: Jody N
authors.initials: JN
authors.lastname: Filkowski
authors.forename: Volodymyr P
authors.initials: VP
authors.lastname: Tryndyak
authors.forename: Andrey
authors.initials: A
authors.lastname: Golubov
authors.forename: Svitlana I
authors.initials: SI
authors.lastname: Shpyleva
authors.forename: Olga
authors.initials: O
authors.lastname: Kovalchuk
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D035683:MicroRNAs / Q000502:physiology*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D002945:Cisplatin; D008156:Luciferases; D035683:MicroRNAs; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; C421109:multidrug resistance-associated protein 1