Fig. 3

CD151 regulates sphingolipid metabolism in part through SPTLC1. a Diagram of sphingolipid metabolic pathway. b Expression of genes involved in sphingolipid metabolism was measured by PCR array in HOS-MNNG cells. Data are shown as log₂-transformed fold change in CD151 silencing cells relative to control. c Spearman correlation analysis of CD151 and SPTLC1 mRNA levels in clinical osteosarcoma samples from the GEO database (GSE42352, n = 127). d and e Western blot analysis of SPTCL1 expression in cells with CD151 depletion (d) or overexpression (e). f The cellular levels of ceramide in WT and CD151 overexpression HOS-MNNG cells with or without myriocin treatment were analyzed by BODIPY FL-labeled ceramide confocal imaging (upper panel); The cellular levels of lipid rafts in WT and CD151 overexpression HOS-MNNG cells with or without myriocin treatment were analyzed by Alexa 555-conjugated CTB confocal imaging (low panel). Scale bars: 50 μm. g Representative images of clonogenic growth in CD151 overexpression cells treated with myriocin. h Tumor volume quantification of established tumors with CD151 overexpression treated with vehicle or myriocin (0.5 mg/kg). Data are presented as mean ± SD, n = 5. i Kaplan–Meier survival curve for each group. The survival rates were calculated when the last mouse was euthanized in the CD151 WT group. Comparisons were made using the two-tailed, unpaired Student’s t-test; The long-rank test was used to test for the significant differences in survival between the groups; *p < 0.05, **p < 0.01, ***p < 0.001