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Vol.49 No.6 contents | Japanese/English |
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- The 23rd Lung Cancer Workshop -
MicroRNA Abnormalities and Their Roles in Lung Cancers
Hirotaka Osada1,21Division of Molecular Oncology, Aichi Cancer Center Research Institute, Japan, 2Department of Cancer Genetics, Nagoya University Graduate School of Medicine, Japan
Objective. MicroRNAs (miRNAs) are small non-coding RNAs, thought to be involved in physiologic and developmental processes by negatively regulating expression of target genes. We assessed alterations of expressions of miRNAs in lung cancers. Methods. We examined the expression of miRNAs using Northern blot and quantitative RT-PCR. We also studied the functions of miRNAs using miRNA expression constructs and antisense oligonucleotides. Results. We found reduced expression of the let-7 family in lung cancers and significantly shorter survival after potentially curative resection in cases with reduced let-7 expression. We also found marked overexpression of the miR-17-92 cluster in lung cancers. Introduction of the expression construct of the miR-17-92 cluster enhanced lung cancer cell growth, whereas inhibition of two members of miR-17-92 cluster, miR-17-5p and miR-20a, with antisense oligonucleotides induced apoptosis selectively in lung cancer cells overexpressing miR-17-92. Conclusion. Our studies suggest that reduced expression of the let-7 family and marked overexpression of the miR-17-92 cluster may play roles in the development of lung cancers. These findings contribute towards better understanding of the anti-oncogenic roles of the let-7 family and oncogenic roles of miR-17-92, which might ultimately lead to future translation into clinical applications.
key words: Lung cancer, microRNA, let-7, miR-17-92
JJLC 49 (6): 894-901, 2009
