Hypoxia facilitates triple-negative breast cancer stem cells enrichment and stemness maintenance through oxidized ataxia telangiectasia mutated-induced one-carbon metabolism

Figure 6 c-Myc regulates serine hydroxymethyltransferase 2 and methylenetetrahydrofolate dehydrogenase 2 expression and cancer stem cell stemness. A: Representative images of mammospheres formed by MDA-MB-231 cells with control, c-Myc knockdown (shc-Myc), or c-Myc overexpression (ov-c-Myc). Scale bar = 200 μm; B and C: Quantification of mammosphere size (B) and mammosphere number (C); D: Western blot analysis of c-Myc, serine hydroxymethyltransferase 2, methylenetetrahydrofolate dehydrogenase 2, Kruppel-like factor 4, and sex-determining region Y-box 2 in MDA-MB-231 cells after shc-Myc or ov-c-Myc treatment; E: Volcano plot showing global metabolic changes following c-Myc knockdown; F: Pathway enrichment analysis of differential metabolites; G: Kyoto Encyclopedia of Genes and Genomes classification of altered metabolic pathways after c-Myc knockdown. MTHFD2: Methylenetetrahydrofolate dehydrogenase 2; SHMT2: Serine hydroxymethyltransferase 2; KLF4: Kruppel-like factor 4; SOX2: Sex-determining region Y-box 2.