title: Expression and significance of miRNA-21 and BTG2 in lung cancer.
abstract: This study investigates the expression of micro-ribonucleic acid-21 (miRNA-21) and B cell translocation gene 2 (BTG2) in lung cancer cells. We examined the impact of miRNA-21 on biological characteristics of lung cancer cells, such as growth, proliferation, apoptosis, and invasion. The expression of miRNA-21 and BTG2 protein in lung cancer cell lines (A549, HCC827, NCI-H292, and 95-D) was examined using quantitative reverse transcription-polymerase chain reaction and Western blot analysis, respectively. Subsequently, the regulatory role of miRNA-21 on BTG2 was explored by inhibiting miRNA-21 expression in 95-D cells using miRNA-21-antisense oligonucleotides (miRNA-21 ASO). The impact of miRNA-21 on the biological characteristics of 95-D cells was further studied using methylthiazol tetrazolium assays, flow cytometry, and Transwell invasion chamber assays. The impact of miRNA-21 on the expression of cyclin D1, caspase-3, and matrix metalloprotease-9 (MMP9) was also studied. miRNA-21 expression was significantly higher in lung cancer cell lines (A549, HCC827, NCI-H282, and 95-D) than that in normal human bronchial epithelial cells (HBE; p < 0.05). The pattern of BTG2 protein expression was exactly the opposite of miRNA-21 expression in lung cancer cells. BTG2 was highly expressed in HBE cells and was expressed at very low levels in lung cancer cell lines (A549, HCC827, NCI-H292, and 95-D). High miRNA-21 expression may inhibit BTG2 protein expression, whereas the inhibition of miRNA-21 expression may promote BTG2 protein expression in 95-D cells. Cell viability and invasion of 95-D cells were significantly lower in the miRNA-21 ASO-transfected group than that in the control ASO-transfected group and untransfected group (p < 0.05). The number of apoptotic cells was significantly higher in the miRNA-21 ASO-transfected group than that in the control ASO-transfected and untransfected groups (p < 0.05). The expression level of cyclin D1 and MMP9 in 95-D cells was significantly lower in the miRNA-21 ASO-transfected group than in the control ASO-transfected and untransfected groups (p < 0.05). Meanwhile, caspase-3 expression was significantly higher in the miRNA-21 ASO-transfected group than that in the control ASO-transfected and untransfected groups (p < 0.05). miRNA-21 overexpression may inhibit the BTG2 gene in lung cancer cells. miRNA-21 may promote cell proliferation and invasion and inhibit cell apoptosis in 95-D cells.
authors.affiliation: Department of Medical Oncology, Wuxi 2nd People's Hospital, Nanjing Medical University, Wuxi, China, sunqingwx@163.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.forename: Meng
authors.initials: M
authors.lastname: Hang
authors.forename: Xuedan
authors.initials: X
authors.lastname: Guo
authors.forename: Wenlong
authors.initials: W
authors.lastname: Shao
authors.forename: Guangqiao
authors.initials: G
authors.lastname: Zeng
mesh_terms: D017209:Apoptosis / Q000235:genetics; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
chemical_list: D017874:Immediate-Early Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D016376:Oligonucleotides, Antisense; D025521:Tumor Suppressor Proteins; D019938:Cyclin D1; C070114:BTG2 protein, human; D053148:Caspase 3; D020780:Matrix Metalloproteinase 9