Effects of suppressed HSP27 on the susceptibility of SK-BR-3 HR to Herceptin. (a) Suppressed HSP27 after transfection with siRNAs in the presence of Herceptin. (b) MTT analysis showed increased Herceptin susceptibility of SK-BR-3 HR after HSP27 suppression. (c) Effect of Herceptin on the levels of Her2 and HSP27. Altered total levels of HSP27 and Her2 by Herceptin treatment. Treatment of Herceptin led to reductions in HSP27 and Her2 levels in the homogenates of SK-BR-3 and SK-BR-3 HR cells. Data (a, b, c) are means ± standard deviations of three independent experiments.