Posttranscriptional control of the chemokine receptor CXCR4 expression in cancer cells
2014
CXCR4is a
chemokine receptorthat is overexpressed in certain cancer types and involved in migration toward distant organs. The molecular mechanisms underlying
CXCR4expression in invasive cancer, particularly posttranscriptional regulation, are poorly understood. Here, we find that
CXCR4harbors
AU-rich elements(AREs) in the 3′-untranslated region (3′-UTR) that bind and respond to the
RNA-binding proteins,
tristetraprolin(TTP/
ZFP36) and HuR (ELAVL1). Different experimental approaches, including RNA immunoprecipitation, 3′-UTR reporter, RNA shift and messenger RNA (mRNA) half-life studies confirmed functionality of the
CXCR4ARE. Wild-type TTP, but not the zinc finger mutant, C124R, was able to bind
CXCR4mRNA and ARE. In the invasive breast cancer phenotype, aberrant expression of
CXCR4is linked to both TTP deficiency and HuR overexpression. HuR silencing led to decreased
CXCR4mRNA stability and expression, and significant reduction in migration of the cells toward the
CXCR4ligand, CXCL12.
Derepressionof TTP using miR-29a inhibitor led to significant reduction in
CXCR4mRNA stability, expression and migration capability of the cells. The study shows that
CXCR4is regulated by ARE-dependent posttranscriptional mechanisms that involve TTP and HuR, and that aberration in this pathway helps cancer cells migrate toward the
CXCR4ligand. Targeting posttranscriptional control of
CXCR4expression may constitute an alternative approach in cancer therapy.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
51
References
25
Citations
NaN
KQI