MicroRNA-205 directly targets Krüppel-like factor 12 and is involved in invasion and apoptosis in basal-like breast carcinoma.
We investigated microRNAs (miRs) specific to its target gene and exerting distinct biological functions for basal-like breast carcinoma (BLBC). Total RNA was extracted and subjected to miR microarray and bioinformatics analysis. Based on the comprehensive analysis, expression of miRs including its target was analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot analysis and immunohistochemistry (IHC). Further functional analyses were conducted including proliferation, invasion and apoptosis. miR-205 was identified as downregulated (less than 0.5-fold) in BLBC relatively to normal control (NC). Gene ontology (GO) analysis suggested miR-205 may directly targeted Krüppel-like factor 12 (KLF12; degree=4). Luciferase assay revealed miR-205 directly targeted KLF12 through binding its 3'-untranslated region (3'-UTR; p=0.0016). qRT-PCR and western blot analysis showed miR-205 expression was low in cells (p=0.007) and tumor tissues (n=6; p=0.0074), and KLF12 RNA/protein was observed at high levels in cells (p=0.0026; p=0.0079) and tumor tissues (n=9; p=0.0083); knock-up of miR-205 increased its expression (p=0.0021) but reduced KLF12 RNA/protein levels (p=0.0038; p=0.009) in cells. Modulation of miR-205 expression by transfecting its mimics in cells, was involved in invasion (p=0.00175) and apoptosis (p=0.006). In conclusion, our results supported that miR-205 was a miR specific to BLBC which functioned as tumor suppressor gene through directly targeting and negatively regulating proto-oncogene KLF12. miR-205 dysregulation was involved in invasion and apoptosis. miR-205 and KLF12 provided a potential diagnosis biomarker and therapeutic approach for BLBC.
Department of Pathology, Shanghai 6th People's Hospital Jinshan Branch, Shanghai 201599, P.R. China.
Bing
B
Guan
Department of Pathology, Shanghai Pudong New Area People's Hospital, Shanghai 201299, P.R. China.
Qing
Q
Li
Department of Cardiothoracic Surgery, Shanghai Children's Hospital, Shanghai 201040, P.R. China.
Li
L
Shen
Department of Pathology, Nanjing Jinling Hospital, Nanjing, Jiangsu 210002, P.R. China.
Qiu
Q
Rao
Department of Pathology, The Second Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China.
Yan
Y
Wang
Department of Pathology, Jiangsu Province People's Hospital, Nanjing, Jiangsu 210029, P.R. China.
Yun
Y
Zhu
Department of Pathology, Nanjing Jinling Hospital, Nanjing, Jiangsu 210002, P.R. China.
Xiao-Jun
XJ
Zhou
Department of Pathology, Shanghai 6th People's Hospital Jinshan Branch, Shanghai 201599, P.R. China.
Xiao-Hong
XH
Li
D017209:Apoptosis / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D000090063:Proto-Oncogene Mas
D051741:Kruppel-Like Transcription Factors; D035683:MicroRNAs; D000090063:Proto-Oncogene Mas; C436492:KLF12 protein, human; C000715470:MAS1 protein, human; C534425:MIR205, human