Exosomal TGF- β1 inhibition reverses exosome- mediated increase of proliferation and colonies area of LAMA84 cells. (a) Cell growth was evaluated by BrdU assay. LAMA84 cells were incubated for 72, 96 hours, or 1 week, with LAMA84-exosomes (10–20 μg/ml) pretreated or not with neutralizing anti TGF-β1 antibodies. The values were plotted as a percentage of the control (untreated cells); each point represents the mean ± SD of three independent experiments. (b) Colony formation assay shows that the co-treatment of LAMA84 with 10 or 20 μg/ml of exosomes pretreated with neutralizing anti TGF-β1 antibody reverses exosome-mediated increase of LAMA84 colonies area. Asterisks indicate a statistically significant values (** p ≤ 0.01; ***p ≤ 0.001).