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

Figure 5 Serine hydroxymethyltransferase 2 and methylenetetrahydrofolate dehydrogenase 2 promote cancer stem cells enrichment and stemness maintenance in triple-negative breast cancer. A: Effects of serine hydroxymethyltransferase 2 knockdown on mammosphere formation, size, and number in Hs578T and MDA-MB-231 cancer stem cells; B: Effects of methylenetetrahydrofolate dehydrogenase 2 knockdown on mammosphere formation, size, and number; C and D: Western blot analysis of stemness-associated proteins Kruppel-like factor 4 and sex-determining region Y-box 2 after serine hydroxymethyltransferase 2 or methylenetetrahydrofolate dehydrogenase 2 knockdown. Scale bar: 200 μm. Data were presented as mean ± SD (n = 3). ^aP < 0.05. MTHFD2: Methylenetetrahydrofolate dehydrogenase 2; SHMT2: Serine hydroxymethyltransferase 2; KLF4: Kruppel-like factor 4; SOX2: Sex-determining region Y-box 2.