Syndecan Isoform Expression in K562 Cells

Full-length SDC1–4 and SDC4 deletion mutants and transfectants, established in K562 cells (ATCC CCL-243), were created as described previously [43 (link),45 (link),46 (link)]. No His-tags were applied for the SDC constructs. Stable SDC transfectants were selected by measuring SDC expression with flow cytometry using APC-labeled SDC antibodies specific for the respective SDC isoform (all RnD Systems (Minneapolis, MN, USA); SDC1: monoclonal rat IgG1 Clone #359103, cat. no. FAB2780A [116 (link),117 (link),118 (link)]; SDC2: monoclonal rat IgG2B Clone #305515, cat. no. FAB2965A [119 (link),120 (link),121 (link)]; SDC3: polyclonal goat IgG, cat. no. FAB3539A [119 (link),122 (link)]; SDC4: monoclonal rat IgG2a clone #336304, cat. no. FAB29181A [45 (link),46 (link)]). SDC4 overexpressing A549 clones, along with WT A549 cells (ATCC CCL-185), were then grown in advanced MEM medium (Thermo Fischer Scientific, Waltham, MA, USA) supplemented with 10% FCS (Gibco, New York, NY, USA) at 37 °C in a humified 5% CO₂ containing air environment.