Extended Data Figure 7: Inhibition of CD36 results in metastatic lipotoxicity, and CD36+ cells are the only cells capable of initiating metastasis.
From: Targeting metastasis-initiating cells through the fatty acid receptor CD36
a, Representative haematoxylin and eosin staining of metastatic lymph nodes from SCC-25-pLucGFP transplants with overexpressed wild-type CD36 or CD36-K164A. Dashed line denotes the areas surrounded by lipid droplets in the CD36-K164A-expressing cells. b, c, Caspase-3 immunostaining of the metastases reported in a and in Cd36 shRNA FaDu-pLucGFP metastatic lymph nodes, showing activated casp-3-positive apoptotic cells in the vicinity of droplets. d, Relative expression levels expressed as percentages of four populations, CD36+ CD44bright, CD36+ CD44dim, CD36− CD44bright and CD36− CD44dim, as determined by FACS analysis of the primary tumour and metastasis of the OSCC cell lines SCC-25, JHU-029, Detroit-562 and FaDu and the PDCs VDH-00, VDH-01 and VDH-02 (n = 4 biological replicates per cell line). e, Genes differentially expressed between CD36+ CD44bright and CD36+ CD44bright populations validated by RT–qPCR with human-specific TaqMan gene expression assays in SCC-25 EV (empty vector), SCC-25 CD36-overexpressing and SCC-25 Cd36 shRNA cells grown in vitro. Human β-2-microglobulin was used as internal control gene (n = 4 biological replicates, *P < 0.05, **P < 0.005, ***P < 0.0005, two-tailed t-test). f, OSSC cells were co-cultured with adipogenic OP9 cells, FACS-sorted and injected into the oral cavity of NSG mice. g, FACS strategy to isolate CD36+ CD44bright, CD36− CD44bright and CD44bright cells from in vitro SCC-25 cells co-cultured with adipogenic OP-9 cells. Serial limiting dilutions of the different populations were injected immediately after FACS sorting. h, i, BLI monitoring (h) and primary tumour quantification (i) of mice injected with CD44bright CD36+ or CD44bright CD36– cells. Yellow arrows denote increased affinity in injected OSCC for the metastatic place, observed in some animals. j, k, Metastasis-initiating cell (MIC) frequency (j) and tumour-initiating cell (TIC) frequency (k) of the three different populations in g, as determined by ELDA software statistical analysis. Source data from mouse experiments are in Supplementary Information.
