FIGURE 4.

Aurin-induced heat shock response elicited in non-malignant human skin cells (Hs27 fibroblasts, HaCaT keratinocytes, primary melanocytes) occurs without impairment of viability. Viability of aurin-exposed (10 μm, 24 h) cells was monitored using flow cytometric analysis (annexin V-PI staining): human metastatic G361 melanoma cells (A), HaCaT keratinocytes (D), Hs27 dermal fibroblasts (G), primary melanocytes (HEMa-LP; J). Numbers in the quadrants indicate viable (AV-negative, PI-negative) in percent of total gated cells (mean ± S.D., n = 3)). In G361 melanoma cells, aurin exposure also occurred in the presence of the pancaspase inhibitor zVADfmk (40 μm; panel A). B, E, H, and K, bar graphs depict analysis of HSPA1A/HMOX1 expression changes induced by aurin treatment (≤10 μm, 24 h) at the mRNA level (quantitative RT-PCR; n = 3). C, F, I, and L, Hsp70/Hsp27/HMOX1 expression changes induced by aurin-treatment (1–10 μm, ≤24 h) at the protein level; immunoblot analysis representative of three independent repeats is depicted.