Figure 2.

Tumor-derived factors promote the expression of lipid transport receptors and lipid uptake in MDSC. (A) The indicated cytokines were measured in normal spleen explant supernatant, tumor-bearer spleen explant supernatant, or 3LL TES. (B) CD49f⁺ tumor cells and CD11b⁺ myeloid cells were sorted by flow cytometry from 3LL subcutaneous tumors. RT-PCR of the indicated genes was conducted. (C-E) BM precursors were cultured for 4 d with 20% TES, G-CSF, GM-CSF, or a combination of G-CSF, GM-CSF, and IL-6. Each cytokine was used at 40 ng/mL. Unstimulated freshly isolated BM cells were used as control. (C) RT-PCR of lipid uptake genes in BM-derived cells. Genes are differentially expressed when fold > 2 and P < 0.05. (D-E) Flow cytometric staining with Bodipy FL C16 (D) and Bodipy 493/503 (E) in CD11b⁺Gr1⁺ BM-derived cells. MFI averages are shown. Data = mean ± SEM; representative of at least 3 independent experiments; *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.