title: Influence of MiR-451 on Drug Resistances of Paclitaxel-Resistant Breast Cancer Cell Line.
abstract: BACKGROUND
  This study aimed to investigate the potential influence of microRNA-451 (miR-451) in drug resistances of the Paclitaxel-resistant breast cancer cell line by transfecting miR-451 mimics and miR-451 inhibitors to MCE-7, MCF-7/EPI, and MCF-7/DOC.
  
  
  METHODS
  Real-time quantitative PCR (qRT-PCR) was performed for detecting whether transfected miR-451 mimics and miR-451 inhibitors could regulate the expression of miR-451 effectively. The apoptosis of the 3 cell lines was measured by applying Annexin V-APC/PI staining. Western blot was used for the detection of the protein expression of Bcl-2 and Caspase 3 after the transfection of miR-451 mimics /inhibitors. Bioinformatics analysis demonstrated that Bcl-2 protein is a potential target gene for miR-451.
  
  
  RESULTS
  In comparison to the control group, after transfection with miR-451 mimics, there was a significant increase in miR-451 expression in MCF-7, MCF-7/EPI, and MCF-7/DOC. Cells in the three cell lines had increased apoptosis, Bcl-2 protein expression decreased significantly, and Caspase protein expression increased obviously. After the transfection with miR-451 inhibitors, miR-451 expression was significantly decreased and apoptosis in the 3 cell lines had no significant decrease compared with the control group.
  
  
  CONCLUSIONS
  Increased miR-451 expression may negatively regulate Bcl-2 mRNA and protein expression, followed by affecting the protein expression of caspase 3, and accelerate the apoptosis in breast cancer, indicating that miR-451 might influence the drug resistances of the Paclitaxel-resistant breast cancer cell line.
authors.affiliation: Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
authors.forename: Xi
authors.initials: X
authors.lastname: Gu
authors.affiliation: Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
authors.forename: Jian-Yi
authors.initials: JY
authors.lastname: Li
authors.affiliation: Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
authors.forename: Jiao
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
authors.forename: Pi-Song
authors.initials: PS
authors.lastname: Li
authors.affiliation: Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China (mainland).
authors.forename: Wen-Hai
authors.initials: WH
authors.lastname: Zhang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry; D017209:Apoptosis; D001943:Breast Neoplasms / Q000235:genetics*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects; D049109:Cell Proliferation; D017931:DNA Primers; D018432:Drug Resistance, Multiple / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells / Q000187:drug effects; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D017239:Paclitaxel / Q000737:chemistry*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C000595707:BCL2 protein, human; D017931:DNA Primers; C531201:MIRN451 microRNA, human; D035683:MicroRNAs; D019253:Proto-Oncogene Proteins c-bcl-2; C505407:CASP3 protein, human; D053148:Caspase 3; D017239:Paclitaxel