Journal: Nature Communications
Article Title: Acid-exposed and hypoxic cancer cells do not overlap but are interdependent for unsaturated fatty acid resources
doi: 10.1038/s41467-024-54435-3
Figure Lengend Snippet: a , b Representative contrast phase pictures ( a ) and quantification ( b ) of the effects of CRISPR-Cas9-based SCD1 gene invalidation on FaDu spheroid growth at day 7 post-formation (vs. control sgRNA); N = 3, n = 2. c – e Quantification of SCD1 (violet) ( c ) ( N = 5) and CA9 (red) immunostaining ( d ) ( N = 5), and representative pictures ( e ) of spheroids made of CRISPR-Cas9-based SCD1-silenced FaDu cells at day 10 post-formation. f , g Spheroid growth ( f ) ( N = 3, n = 3–4) and cytotoxicity (Incucyte Cytotox Green reagent) follow up ( g ) ( N = 3, n = 4) after exposure to SCD1 inhibitor (or vehicle) for 72 h in FaDu spheroids. h , i Representative pictures ( h ) and quantification of CA9 (red) ( i ) in sections of FaDu spheroids collected after 72 h exposure to SCD1 inhibitor ( N = 3, n = 2). j Flow cytometry analysis of CA9 labeling from FaDu cells isolated from spheroids after 72 h exposure to SCD1 inhibitor (or vehicle) ( N = 3). k Quantification of pimonidazole (green) in sections of FaDu spheroids collected after 72 h exposure to SCD1 inhibitor ( N = 3, n = 2). l , m Mitochondrial oxygen consumption rate (OCR) of l FaDu ( N = 3, n = 7) and HCT116 ( N = 3, n = 7–8) spheroids after 72 h SCD1 inhibition and ( m ) FaDu cancer cells transduced with the indicated SCD1 sgRNA ( N = 3, n = 3) or control sgRNA ( N = 3, n = 3–4). n Non-mitochondrial OCR of FaDu cells transduced with an SCD1-expressing vector or control plasmid and exposed to palmitate ( N = 3, n = 3) or vehicle (FA-free BSA) ( N = 3, n = 4). o – r Representative pictures ( o ) and quantification of SCD1 (violet) ( p ), CA9 (red) ( q ), and pimonidazole (green) ( r ) staining in FaDu spheroids exposed to PPAR-γ inhibitor (or vehicle) for 72 h ( N = 3); the effects of a PPAR-α inhibitor are also shown in graphs ( p – r ). All treatments ( f – l ) with SCD1 inhibitor (A939572, 32 µM) were initiated at day 7 after spheroid formation (i.e., timing 0 on graphs). All immunostaining quantifications ( c , d , i , k , p – r ) were normalized to the DAPI nuclear staining area. Data are plotted as the means ± SD ( P -values as indicated or *** P < 0.001, **** P < 0.0001); N indicates the number of independent experiments and n indicates the number of biological replicates (when >1). Significance was determined by one-way ANOVA with Tukey’s multiple comparison tests ( b – d ), Dunnet’s multiple comparison tests ( p – r ), Sidaks’s multiple comparison tests ( f , g ), two-way ANOVA with Tukey’s multiple comparison tests ( l – n ) or two-sided Student’s t -tests ( i – k ). Source data are provided as a Source Data file.
Article Snippet: 6.5 and 7.4 pH-adapted 2D cell lines were collected and stained with PE-coupled anti-CA9 antibody (130-123-340, Miltenyi, 1:200) for 20 min at 4 °C.
Techniques: CRISPR, Control, Immunostaining, Flow Cytometry, Labeling, Isolation, Inhibition, Transduction, Expressing, Plasmid Preparation, Staining, Comparison