Fig. 1

BC cell sialylation and susceptibility to chemotherapy is nutrient dependent and internally inversely related. A Representative confocal microscopy images of MDA-MB-231, MCF-7 and MCF-10A cells obtained using azide-alkyne click-chemistry following metabolic labeling of membrane sialic acids in the respective nutrient media: high glucose (HG), low glucose (LG) and HBLG (3-hydroxybutyrate-containing, low glucose). Green: AF488; scale bar: 100 µm. All images were collected at identical conditions and are displayed with the same LUT. B Relative sialylation levels in each cell line normalized to HG control as quantified using AF 488 intensity/perimeter of membrane in an image of labeled cells. For each cell type, images from two separate experiments (N = 2) were used with 10–15 different FOVs collected for each experiment. A custom pipeline created in Cell profiler was used for quantification based on generation of membrane mask using an image of the cells with CellBrite Membrane stain. Scatter plots shown here with black horizontal lines representing means, and error bars representing the standard error of mean (SEM), p-values were calculated using a two-tailed unpaired t-test in GraphPad Prism. C Normalized relative cytotoxicity of DOX (1µM) in MDA-MB-231, MCF-7 and MCF-10A cells in the respective nutrient media plotted using mean values where error bars represent SEM and p-values were computed using a two-tailed unpaired t-test in GraphPad Prism. *, **, *** indicate p < 0.05, p < 0.01, and p < 0.001, respectively