title: Effects of miR-155 antisense oligonucleotide on breast carcinoma cell line MDA-MB-157 and implanted tumors.
abstract: Diverse studies have shown that miR-155 is overexpressed in different tumor types. However, the precise molecular mechanism of the ectopic expression of miR-155 in breast cancer is still poorly understood. To further explore the role of miR-155 in breast tumorigenesis, we here assessed the influence of miR-155 antisense oligonucleotide (miR-155 ASO) on MDA-MB-157 cell viability and apoptosis in vitro. Furthermore, the effects of inhibitory effects of miR-155 on the growth of xenograft tumors in vivo were determined with performance of immunohistochemistry to detect expression of caspase-3, a pivotal apoptosis regulatory factor, in xenografts. Transfection efficiency detected by laser confocal microscope was higher than 80%. The level of miR-155 expression was significantly decreased (P<0.05) in the cells transfected with miR-155 ASO, compared with that in cells transfected with a negative control. After being transfected with miR-155 ASO, the viability of MDA-MB-157 cells was reduced greatly (P<0.05) and the number of apoptotic cells was increased significantly. Additionally, miR-155 ASO inhibited the growth of transplanted tumor in vivo and significantly increased the expression of caspase-3. Taken together, our study revealed that miR-155 ASO can induce cell apoptosis and inhibit cell proliferation in vitro. Moreover, miR-155 ASO could significantly repress tumor growth in vivo, presumably by inducing apoptosis via caspase-3 up-regulation. These findings provide experimental evidence for using miR-155 as a therapeutic target of breast carcinoma.
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, China.
authors.forename: Shu-Rong
authors.initials: SR
authors.lastname: Zheng
authors.forename: Gui-Long
authors.initials: GL
authors.lastname: Guo
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhai
authors.forename: Zhang-Yong
authors.initials: ZY
authors.lastname: Zou
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D053148:Caspase 3 / Q000378:metabolism; D049109:Cell Proliferation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000037:antagonists & inhibitors* / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D053148:Caspase 3