Fig. 2: Detection of target receptor expression in circulating tumor cells.

a Illustration showing the experimental model for CTC analysis from mice bearing GBM xenografts. b Illustration showing the principle underlying CTC isolation from blood samples using CELLTRACKS system and subsequent analysis. c Plot showing CD105⁺/CD45⁻ GBM CTC isolated and enumerated from mice bearing GBM tumor xenografts harvested and analyzed at day 21 (n = 3 mice/group). d Photomicrographs showing CD105 and CD45 staining on single cells as obtained from the analyzer. e Photomicrographs revealing mCherry Fluorescence and DR5 staining on GBM-FmC-CTC isolated from mice. f Plot showing surface expression of DR5 on GBM cells and corresponding GBM-CTC by flow cytometry. g Plot showing surface expression of DR4 on GBM cells and their corresponding GBM-CTC. h Schematic depicting the workflow for CTC isolation and analysis for clinical blood samples. i Plot showing the number of CD146⁺/CD105⁺/CD45⁻ CTC isolated from various deidentified GBM patient samples prior to surgical debulking of tumor. j Plot showing cell surface DR5 receptor expression on clinical CTC samples by flow cytometry. Scale bars 50 μM (d) and 100 μM (e). Data are shown as mean ± S.E.M.