title: High expression of miR-21 in triple-negative breast cancers was correlated with a poor prognosis and promoted tumor cell in vitro proliferation.
abstract: The triple-negative breast cancer (TNBC), with a particularly poor prognosis, is increasingly recognized as heterogeneous in molecular signatures. MicroRNA expression profiles have been used for the classification and prognostication of breast cancer, numerous significantly upregulated microRNAs, i.e. miR-21, have been verified oncogenic in non-TNBCs. In present study, we determined the miR-21 levels in TNBC specimens, and TNBC cell levels in vitro, and then identified the role of miR-21 on tumor cell proliferation, apoptosis, and then identified PTEN as the possible target of the microRNA. It was shown that miR-21 expression is upregulated generally, and heterogeneous in TNBC specimens, posing a correlation with poor prognosis for TNBC patients. Further results demonstrated that the upregulated miR-21 promoted the tumor proliferation and inhibited cell apoptosis in vitro. And pro-apoptotic PTEN had been shown being targeted and downregulated. Therefore, our finding emphasized the oncogenic role of miR-21 in TNBC.
authors.affiliation: Radiotherapy Central of PLA 404 Hospital, No. 8 Baoquan Road, HuanCui District, Weihai, 264200, Shandong, China, guizhdong@163.com.
authors.forename: Guizhi
authors.initials: G
authors.lastname: Dong
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Liang
authors.forename: Deguang
authors.initials: D
authors.lastname: Wang
authors.forename: Huiquan
authors.initials: H
authors.lastname: Gao
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Jingjun
authors.initials: J
authors.lastname: Liu
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Du
mesh_terms: D020413:3' Untranslated Regions; D017209:Apoptosis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000235:genetics; D011379:Prognosis; D064726:Triple Negative Breast Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology / Q000628:therapy
chemical_list: D020413:3' Untranslated Regions; D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human