Fig. 8: Palmitic acid accumulates in tumor regions and modulates macrophage phenotype.
From: Chemosensor receptors are lipid-detecting regulators of macrophage function in cancer
a, Representative images of patient biopsies analyzed by hematoxylin and eosin (H&E; T, neoplastic tissue; A, adjacent normal tissue); spatial analysis of the distribution of palmitic acid by mass spectrometry imaging; and mosaic immunofluorescence showing CD68 (green), pancytokeratin (Pan-CK, red) and nuclei (DAPI, blue). b, Quantification of palmitic acid in patient biopsies, comparing tumoral (Tum.) versus nontumoral (No tum.) areas within each patient. n = 4 patients. Two-tailed paired Student’s t-test was used for the statistical analysis. c, H&E and spatial analysis of the distribution of palmitic acid by mass spectrometry imaging in patient number 2. d, Segmented images (inset) showing nontumor (left) and tumor (right) regions. e, Heat map showing significant pairwise cell–cell interaction (red) or avoidance (blue) across the nontumor and tumor regions. f, UMAP identifying two nontumoral and two tumor clusters. g, Spatial distribution of the cluster shown in f. h, Spatial distribution of inflammatory TAM (Inflam-TAM), TAM defined by Cl3 interferon-related genes (IFN-TAM), lipid-laden TAM (LA-TAM), angiogenic TAM (Angio-TAM) and Cl6 regulatory TAM (Reg-TAM) signatures in patient number 2; image represents the enrichment of each signature and its spatial distribution. i, Distribution of each signature from h in the four identified areas: each dot represents a gene, and the size of the dot is representative of the expression level (exp.) of the gene. j, Bubble plot representing the expression of selected genes in the four identified areas. Unless otherwise specified, statistical analyses were performed using two-tailed unpaired Student’s t-test. Values are presented as the mean ± s.e.m. Max., maximum; Min., minimum; TH cell, T helper cell.
