Premium
A microRNA pulldown approach uncovers regulation of p53 activity and growth factor signaling by miR‐34a
Author(s) -
LAL ASHISH,
THOMAS MARSHALL,
Navarro Francisco,
Li Xiao Ling,
Lieberman Judy
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.203.3
Subject(s) - microrna , signal transduction , mapk/erk pathway , biology , microbiology and biotechnology , ectopic expression , gene , growth factor , cell growth , transfection , protein kinase b , cancer research , genetics , receptor
A simple biochemical method to isolate mRNAs pulled down with a transfected, biotinylated microRNA was used to identify direct target genes of miR‐34a, a tumor suppressor gene. The method reidentified most of the known miR‐34a regulated genes expressed in K562 and HCT116 cells. The transcripts pulled down with miR‐34a were highly enriched for their roles in growth factor signaling and regulation of p53 activity. These genes regulate multiple signal transduction pathways that orchestrate the proliferative response to external growth stimuli. Multiple candidate miR‐34a‐regulated genes participate in RAS‐RAF‐MAPK signaling. Ectopic miR‐34a expression reduced basal ERK and AKT phosphorylation and enhanced sensitivity to serum growth factor withdrawal, while cells genetically deficient in miR‐34a were less sensitive. Several novel direct targets of miR‐34a were experimentally validated, including genes that participate in growth factor signaling as well as genes that regulate p53 activity. Thus miR‐34a tempers the proliferative and pro‐survival effect of growth factor stimulation by interfering with growth factor signal transduction and downstream pathways required for cell division.