Fig. 2
PDGFRβ promotes autocrine growth in ALCL. A Live cell counts of (n = 4) fl/fl Pdgfrb (grey) and (n = 4) Δ/Δ Pdgfrb (orange) primary mouse tumor cell lines seeded in 6-well plates at low confluency (1 × 105 cells). Cells were stained with Trypan blue and live cell counts were recorded on days two, four and six. B Representative pictures of a fl/fl Pdgfrb cell line (PdgfrbEV; empty vector transduced) subjected to CRISPR/Cas9 deletion of Pdgfrb (PdgfrbΔCRISPR) and seeded in a 96-well plate for a limiting dilution assay. Right graph: arbitrary fluorescence units measured using a resazurin assay were measured and correlated to the matched empty vector control (n = 5). C Longitudinal analysis of tumor volume increase of 6-week old immunodeficient (NOD.Cg-Prkdcscid, Il2rdtm1Wjl/SzJ) female mice inoculated with either (n = 8) fl/fl Pdgfrb (grey) or (n = 8) Δ/Δ Pdgfrb (orange) primary mouse tumor cell lines at a low concentration (1 × 105 cells/flank). D Kaplan Meier cumulative survival analysis of 6-week old NSG female mice inoculated with either (n = 8) fl/fl Pdgfrb (grey) or (n = 8) Δ/Δ Pdgfrb (orange) primary mouse tumor cell lines at a low concentration (1 × 105 cells/flank). Values next to the dotted lines on the x-axis indicate median life expectancy before tumor size reaches the 2000 mm3, the set threshold volume. E Heatmap depicting cytokine concentrations (pg/ml) in the supernatants of (n = 3) fl/fl Pdgfrb and (n = 3) Δ/Δ Pdgfrb primary mouse tumor cell lines cultivated in vitro at a low density (1 × 105 cells). F Quantitative RT-qPCR of Il-10 mRNA transcripts from (n = 8) fl/fl Pdgfrb (grey) and (n = 6) Δ/Δ Pdgfrb (orange) primary mouse tumor cell lines. Data was normalized to 18S ribosomal RNA expression. G Gene comparison between (n = 6) ALCL patients and healthy donors of the Piccaluga dataset [32] extrapolated from the Oncomine database [34]. Heatmap colors represent z-scores normalized to depict relative values within rows, where blue represents least expressed and red represents most expressed. A, B and F Data are shown as means ± SD, and p values were determined by the unpaired two-tailed Student’s t-test. D p value was determined by log-rank (Mantel-Cox) test (ns = p > 0.05; * = p < 0.05; ** = p < 0.01; *** = p < 0.001; **** = p < 0.0001)