title: MicroRNA-21 controls hTERT via PTEN in human colorectal cancer cell proliferation.
abstract: Colorectal cancer is a major health problem worldwide. The aim of this study was to determine a role of microRNA-21 (miRNA-21) in colorectal cancer (CRC) and to elucidate miRNA-21 regulation of hTERT by phosphatase and tensin homologue (PTEN). Protein and mRNA samples were extracted with 30 CRC samples and one CRC cell lines. The expression of miRNA-21, hTERT, PTEN in CRC tissues and CRC cell lines was measured by real-time fluorescent quantitative PCR, Western blotting. Cell viability was detected by MTT and cell cycle assay. In this study, we show that the expression of miRNA-21 was overexpressed in CRC tissue and CRC cell lines compared with the control group. The effects of miRNA-21 were then assessed in MTT assays through in vitro transfection with a miRNA-21 mimic or inhibitor. PTEN has been identified as a target gene of miRNA-21 in CRC cell lines. Moreover, Western blot and qRT-PCR analyses revealed that miRNA-21 increased the expression of human telomerase reverse transcriptase (hTERT) via the PTEN/ERK1/2. In addition, Western blot analyses confirmed that an inverse correlation between PTEN and hTERT levels of high miRNA-21 RNA-expressing CRC tissues and cell lines. Finally, these data indicate that miRNA-21 regulates hTERT expression via the PTEN/ERK1/2 signaling pathway, therefore controlling CRC cell line growth. MiRNA-21 may serve as a novel therapeutic target in CRC.
authors.affiliation: Clinical College of General Hospital of Armed Police Forces, Anhui Medical University, Hefei, 230032, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Tao
authors.forename: Wei-Sen
authors.initials: WS
authors.lastname: Jin
mesh_terms: D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D020935:MAP Kinase Signaling System; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D019098:Telomerase / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C509186:TERT protein, human; D019098:Telomerase; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human