Gene signature of response to 17AAG in breast cancer cell lines. A) Heat-map represents the expression of significant differentially expressed 35 genes included in the molecular signature of response to 17AAG. Untreated samples were compared to treated samples from all sensitive cell lines to obtain common variations. B) Comparison between the changes in expression in the genes included in the signature in sensitive and resistant cells. Fold changes after 17AAG for sensitive cell lines, taken the averaged expression of all of them, compared to fold changes in resistant MDA-MB-231 cells or T47 D.Error bars represent standard deviation. C) Western blot analysis of different HSP70 isoforms before and after 17AAG in resistant MDA-MB-231 and sensitive MCF-7 cell line showed differential HSP70 induction after 17AAG. Lack of induction of the HSPA2 and HSPA1L in resistant cells, and increased expression of HSP72 and HSC70 in both resistant and sensitive cell lines upon treatment is shown. GAPDH was used as loading control.