Genetic or pharmacological inhibition of HuR reduces ARID1A levels. Twenty-four hours after transfection with HuR siRNA, MDA-MB-231 and Hs578t cells were treated with a radiation dose of 5 Gy; 2 h later, they were evaluated for ARID1A expression by (A,B) Western blot or (C,D) (q) RT-PCR analyses. MDA-MB-231 and SUM159PT cells treated with HuR inhibitor, CMLD-2, for 24 h were collected to evaluate ARID1A expression levels. (E,F) As a control for HuR inhibition, p27 expression was also evaluated in MDA-MB-231 and SUM159PT following CMLD-2 treatment. Data presented are the average of three independent experiments. Error bars represent SEM (standard error of the mean), * p ≤ 0.01 and ** p ≤ 0.001.