Fig. 2

Chemo-residual triple-negative (TN) breast cancer cells from a short-term chemotherapy treatment model exhibit increased expression of a nuclear isoform of basic fibroblast growth factor (bFGF). a Increased bFGF RNA in chemo-residual SUM159 cells after doxorubicin treatment as described in Fig. 1a. Total RNA was extracted from parental and chemo-residual cells. bFGF mRNA expression was quantified by qRT-PCR, and is shown as fold increase relative to β-actin. Error bars represent SD, n = 3, **p <0.01, two-tailed Student’s t test. b Left panel: increased expression of nuclear, but not cytosolic bFGF in chemo-residual SUM159 cells after doxorubicin or docetaxel treatment (as described in Fig. 1a). Nuclear or cytosolic protein was extracted from parental and chemo-residual cells. Equivalent amounts were immunoblotted with bFGF, Lamin A, or GAPDH antibody, followed by IrDye-conjugated secondary antibodies. Protein bands were detected by infrared imaging. Right panel: protein bands from three independent trials (doxorubicin treatment, as described in Fig. 1a) were quantified using Image J software (NIH), and the relative ratio of nuclear bFGF to loading control is shown for parental and chemo-residual SUM159 cells. Error bars represent SD, n = 3, ***p <0.001, two-tailed Student’s t test. c SUM159 and BT549 cells were treated with doxorubicin as described in Fig. 1a. Parental and chemo-residual cells were fixed and stained with Hoechst (blue) and bFGF antibody (red) to demonstrate the increased nuclear localization of bFGF in chemo-residual TN breast cancer cells. Magnification ×400.