Upregulation of miR-136 in human non-small cell lung cancer cells promotes Erk1/2 activation by targeting PPP2R2A.

TitleUpregulation of miR-136 in human non-small cell lung cancer cells promotes Erk1/2 activation by targeting PPP2R2A.
Publication TypeJournal Article
Year of Publication2013
AuthorsShen S, Yue H, Li Y, Qin J, Li K, Liu Y, Wang JX
JournalTumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine
Date Published2013 Aug 20
Abstract

MicroRNAs (miRNAs) have been integrated into cancer development and progression, because they repress translation of target genes which can be tumor suppressors and oncogenes. A number of miRNAs have been found to be closely related to human non-small cell lung cancer (NSCLC). However, the roles of miR-136 in NSCLC are still largely unknown. Here, we show that miR-136 is significantly upregulated in human NSCLC primary tumors and cell lines compared to their nontumor counterparts. Suppression of miR-136 expression in NSCLC cell line A549 inhibited both anchorage-dependent and anchorage-independent proliferation. Further studies showed that suppression of miR-136 expression attenuated phosphorylation of extracellular-signal-regulated kinase 1/2 (Erk1/2). We found that serine/threonine protein phosphatase 2A 55 kDa regulatory subunit B α isoform (PPP2R2A, also known as B55α) was a direct target of miR-136, and suppression of miR-136 expression led to a robust increase in both mRNA and protein levels of PPP2R2A. We found that miR-136 promoted phosphorylation of Erk1/2 through inhibition of PPP2R2A expression, and forced overexpression of PPP2R2A abrogated promotion of Erk1/2 phosphorylation by miR-136. Moreover, forced overexpression of PPP2R2A abrogated the promoting effect of miR-136 on cell growth and led to a reduced growth rate of NSCLC cells. Our findings indicate that miR-136 promotes Erk1/2 phosphorylation through targeting PPP2R2A in NSCLC cells and suggest that it may serve as a therapeutic target in NSCLC therapy.

DOI10.1039/c3cc44336a
Alternate JournalTumour Biol.