Send to

Choose Destination
Clin Chim Acta. 2010 Jun 3;411(11-12):846-52. doi: 10.1016/j.cca.2010.02.074. Epub 2010 Mar 16.

MicroRNA-21 (miR-21) represses tumor suppressor PTEN and promotes growth and invasion in non-small cell lung cancer (NSCLC).

Author information

Thoracic Surgery Department, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430022, People's Republic of China.



MicroRNAs (miRNAs) are a class of small non-coding RNAs regulating gene expression that play roles in the pathogenesis of human diseases, including malignancy. miR-21, a commonly overexpressed miRNA in very diverse types of malignancies, may affect tumor progression through targeting tumor suppressor genes. We identified the role of miR-21 in non-small cell lung cancer (NSCLC) and to clarify the regulation of PTEN by miR-21 and determine mechanisms of this regulation.


Expression of miR-21 and PTEN in 20 paired NSCLC and adjacent non-tumor lung tissues was investigated by qRT-PCR and western blot, respectively. The effect of miR-21 on PTEN expression was assessed in NSCLC cell lines with miR-21 inhibitor to decrease miR-21 expression. Furthermore, the roles of miR-21 in cell growth and invasion were analyzed with miR-21 inhibitor-transfected cells.


miR-21 was overexpressed in tumor tissues relative to adjacent non-tumor tissues. Notably, patients with advanced clinical TNM stage (n=16) or distal metastasis (n=5) demonstrated higher miR-21 expression than those without them (n=26, or n=37) (p<0.05, or p<0.001). Tumor tissues showed an inverse correlation between miR-21 and PTEN protein. miR-21 inhibitor transfection increased a luciferase-reporter activity containing the PTEN-3'-UTR construct and increased PTEN protein but not PTEN-mRNA levels in NSCLC cell lines. Finally, miR-21 inhibitor-transfected cells exhibited markedly reduced cell growth and invasive characteristics.


miR-21 post-transcriptionally down-regulates the expression of tumor suppressor PTEN and stimulates growth and invasion in NSCLC. It may be a potential therapeutic target for NSCLC.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center