Figure 4

miR-21 downregulation regulates the cellular response to radiation. (A) T47D cells were infected with empty lentivirus (+ EV), with miR-21 overexpressing LV (+ miR-21) or inhibitory miR-21 LV (+ anti-mir-21) and analysed for miRNA expression in MDA-MB-361 cells (light gray boxes) and T47D cells (dark gray boxes) 72 hours after infection. MDA-MB-361 control sample was used as reference for miR-21 expression (set as 1). (B) Cell proliferation assay (WST1) in T47D cells with miR-21 overexpression or downregulation and corresponding radiation treatment after 72 hours in control cells (dark gray boxes), or after 2.5 Gy (gray boxes) and 5 Gy (light gray boxes) 72 hours after irradiation. (C) Cell proliferation assay (WST1) in MDA-MB-361 cells with miR-21 overexpression or downregulation and corresponding radiation treatment after 72 hours. Data represent the means ± SD (n=3). *p <0.05, **p <0.01, ***p <0.001 by ANOVA.