title: Expression and regulatory function of miRNA-182 in triple-negative breast cancer cells through its targeting of profilin 1.
abstract: We aimed to evaluate the expression of microRNA-182 (miR-182) in triple-negative breast cancer (TNBC) tissues and the TNBC cell line MDA-MB-231 and to investigate the effects of mirR-182 on the cellular behavior of MDA-MB-231 and the expression of the target gene profilin 1 (PFN1), thus providing new methods and new strategies for the treatment of TNBC. Quantitative real-time PCR (qRT-PCR) was utilized to evaluate the expression of miR-182 in TNBC tissues, relatively normal tissues adjacent to TNBC and the TNBC cell line MDA-MB-231. Forty-eight hours after the MDA-MB-231 cells were transfected with the miR-182 inhibitor, qRT-PCR was utilized to detect the changes in miR-182 expression levels, and an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was utilized to determine the effects of miR-182 on cell viability. Flow cytometry was adopted to determine whether miR-182 affects the proliferation rates and apoptosis levels of the MDA-MB-231 cells. The transwell migration assay method was used to investigate the effects of miR-182 on the migration of the MDA-MB-231 cells. A luciferase reporter gene system was applied to validate that PFN1 was the target gene of miR-182. Western blot was used to measure the effects of miR-182 on the PFN1 protein expression levels in the cells. qRT-PCR results showed that compared with the relatively normal tissues adjacent to TNBC, miR-182 expression was significantly increased in the TNBC tissues and the MDA-MB-231 cells (p<0.01). Compared with the control group, MDA-MB-231 cells transfected with the miR-182 inhibitor and incubated for 48 h showed significantly decreased miR-182 expression (p<0.01). The results of an MTT assay showed that inhibition of miR-182 in MDA-MB-231 cells led to significantly reduced cell viability (p<0.05). Flow cytometry analysis indicated that inhibition of miR-182 expression resulted in significantly decreased cell proliferation (p<0.05) and significantly increased levels of apoptosis (p<0.05). The results of a transwell migration assay showed that after inhibited of miR-182 expression, the number of cells passing through the transwell membranes was significantly decreased (p<0.05). The results from a luciferase reporter gene system showed that compared with the control group, the relative luciferase activity of the group transfected with the miR-182 inhibitor was significantly increased (p<0.05). Western blot analysis showed that compared with the control group, PFN1 protein expression levels were significantly increased in the MDA-MB-231 cells transfected with the miR-182 inhibitor and incubated for 48 h (p<0.05). In conclusion, miR-182 is upregulated in TNBC tissues and cells. It promotes the proliferation and invasion of MDA-MB-231 cells and could negatively regulate PFN1 protein expression. Treatment strategies utilizing inhibition of miR-182 expression or overexpression of the PFN1 gene might benefit patients with TNBC.
authors: Division of Breast Surgery, Department of General Surgery, General Hospital of Chinese People's Liberation Army (301 Hospital), No. 28, Fuxing Rd, Beijing, 100853, People's Republic of China.
authors: Hailing
authors: H
authors: Liu
authors: Yan
authors: Y
authors: Wang
authors: Xin
authors: X
authors: Li
authors: Yan-jun
authors: YJ
authors: Zhang
authors: Jie
authors: J
authors: Li
authors: Yi-qiong
authors: YQ
authors: Zheng
authors: Mei
authors: M
authors: Liu
authors: Xin
authors: X
authors: Song
authors: Xi-ru
authors: XR
authors: Li
mesh_terms: D017209:Apoptosis; D015153:Blotting, Western; D001940:Breast / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D008156:Luciferases / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D051304:Profilins / Q000235:genetics* / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D008156:Luciferases; D035683:MicroRNAs; D051304:Profilins; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C538984:Mirn182 microRNA, human; C495738:PFN1 protein, human