RK-33 treatment but not DDX3X knockdown suppresses OC43 growth. (A,B) MRC-5 cells were infected at an MOI of 0.1. Medium containing 1 μM RK-33 or DMSO was added to cells after 1 h of viral absorption, and cells were harvested and analyzed by WB (A) or qPCR (B) 8 h postinfection (hpi). Representative blot of four independent experiments is displayed. (C–G) MRC-5 cells were transfected with 20 nM siRNAs for ∼48 h, infected with OC43 with or without RK-33 for 8 hpi and analyzed as in A and B. Representative blots are shown from four (B) or three (F) independent experiments. qPCR quantification is made from at least three independent experiments. Statistical significance: (ns) not significant, (*) P ≤ 0.05, (**) P ≤ 0.01, (***) P ≤ 0.001, (****) P ≤ 0.0001. Tests used: one-sample t-test (A,G,F), two-sample t-test (B), one-sample and two-sample t-test (C,D,E). Error bars represent mean ± SEM.
