miR-21-mediated tumor growth

• Published in: Oncogene Vol. 26; no. 19; pp. 2799 - 2803
• Main Authors: SI, M.-L, ZHU, S, WU, H, LU, Z, WU, F, MO, Y.-Y
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing 26-04-2007; Nature Publishing Group
• Subjects: Animals; Antisense nucleic acids; Apoptosis; Bcl-2 protein; Biological and medical sciences; Breast - metabolism; Breast cancer; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cell growth; Cell physiology; Cell Proliferation; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Development and progression; Female; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Neoplastic; Gene regulation; Genetic aspects; Genetic transcription; Genetics; Health aspects; Humans; Mice; Mice, Nude; MicroRNAs; MicroRNAs - antagonists & inhibitors; MicroRNAs - physiology; miRNA; Molecular and cellular biology; Molecular genetics; Oligonucleotides; Oligonucleotides, Antisense - pharmacology; Oncogenes; Polymerase chain reaction; Post-transcription; Proto-Oncogene Proteins c-bcl-2 - metabolism; Ribonucleic acid; RNA; RNA Processing, Post-Transcriptional; RNA, Messenger - genetics; RNA, Messenger - metabolism; Rodents; Therapeutic targets; Transcription. Transcription factor. Splicing. Rna processing; Tumor cells; Tumorigenesis; Tumors; Xenograft Model Antitumor Assays; Xenografts; United States; Bcl-2; RNA interference; Transcription; MCF-7; post-transcriptional regulation; Micro RNA; Malignant tumor; Carcinogenesis; Gene silencing; Regulation(control); C-Onc gene; miRNA; miR-21; Protooncogene
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/sj.onc.1210083

MicroRNAs (miRNAs) are approximately 22 nucleotide non-coding RNA molecules that regulate gene expression post-transcriptionally. Although aberrant expression of miRNAs in various human cancers suggests a role for miRNAs in tumorigenesis, it remains largely unclear as to whether knockdown of a specific miRNA affects tumor growth. In this study, we profiled miRNA expression in matched normal breast tissue and breast tumor tissues by TaqMan real-time polymerase chain reaction miRNA array methods. Consistent with previous findings, we found that miR-21 was highly overexpressed in breast tumors compared to the matched normal breast tissues among 157 human miRNAs analysed. To better evaluate the role of miR-21 in tumorigenesis, we transfected breast cancer MCF-7 cells with anti-miR-21 oligonucleotides and found that anti-miR-21 suppressed both cell growth in vitro and tumor growth in the xenograft mouse model. Furthermore, this anti-miR-21-mediated cell growth inhibition was associated with increased apoptosis and decreased cell proliferation, which could be in part owing to downregulation of the antiapoptotic Bcl-2 in anti-miR-21-treated tumor cells. Together, these results suggest that miR-21 functions as an oncogene and modulates tumorigenesis through regulation of genes such as bcl-2 and thus, it may serve as a novel therapeutic target.