Fig. 1.

High HSF1 expression is associated with CSCs in multiple cell lines. a HSF1 is highly expressed in CSC-like BPLER cells that express CSC-associated markers CD326, high-molecular weight CD44v, and CD166 compared to isogenic non-CSC-like HMLER cells with low CSC marker expression. Western blot of three matched pairs (#2, 3, and 4) of HMLER and BPLER cell lines was performed with antibodies against HSF1, CD326, CD44, and CD166. β-actin (Actin) was used as loading control. CD44H: CD44 standard form. b HSF1 is highly expressed in FACS-enriched CD44^high/CD166^high CSC population (+/+) compared to CD44^low/CD166^low non-CSC population (−/−) in multiple breast cancer cell lines; MCF7, T47D, BT20, BT474, and HCC1954. Western blot of protein lysates were performed with anti-HSF1 and CD44 antibodies, β-actin (Actin) was used as loading control. c Double immunofluorescence demonstrates that HSF1 and CSC markers are co-expressed in the same subpopulation of cells in situ in multiple breast cancer cell lines; MCF7, MDAMB231, BT474, and T47D. The cells were plated in 8-chamber slides and simultaneously probed with HSF1 (green) and CSC antibodies CD44 or CD326 (red), and overlaid with nuclear DAPI stain (blue) and images were captured with an EVOS fluorescence microscope at 20X magnification