Fig. 6: FLAD1 promotes SREBP1 expression through FAD-LSD1 signaling. | Nature Communications

Fig. 6: FLAD1 promotes SREBP1 expression through FAD-LSD1 signaling.

From: Copy number amplification of FLAD1 promotes the progression of triple-negative breast cancer through lipid metabolism

Fig. 6

a Schematic diagram showing the FAD-dependent demethylation mechanism of mono-methylated and di-methylated lysine residues by LSD1. b Relative protein levels of H3K4me2 and H3K9me2 following shRNA-mediated knockdown of FLAD1 in LM2-4175 and SUM159 cells. c Relative protein levels of H3K4me2 and H3K9me2 following the overexpression of WT FLAD1 and FLAD1-R530C in HCC1806 and Hs578T cells. d The expression of H3K4me2 and H3K9me2 were evaluated by western blot in control and LSD1 knockdown LM2-4175 and SUM159 cells. e The expression of H3K4me2 and H3K9me2 were evaluated by western blot in control and pharmacologic LSD1 inhibition SUM159 cells. f The expression of lipogenic genes were detected by RT-qPCR in control and LSD1 knockdown LM2-4175 and SUM159 cells. g The protein expression of lipogenic genes were showed in the indicated LM2-4175 and SUM159 cells. h The protein levels of LSD1, SREBP1 and lipogenic genes in LSD1 overexpressing SUM159 cells after SREBP1 was knocked down. i, j Relative mRNA (i) and protein (j) levels of genes associated with fatty acid and cholesterol biosynthesis in HCC1806 and Hs578T cells expressing the control vector, WT FLAD1 and WT FLAD1 treated with 80 µM GSK-LSD1 for 24 h. k Schematic of the ChIP-qPCR primers designed for the SREBP1 promoter regions. l The enrichment levels of H3K4me2 and H3K9me2 in different regions of the SREBP1 gene promoter in SUM159 cells with or without FLAD1 knockdown were determined by ChIP-qPCR assay. m The enrichment levels of H3K9me2 in different regions of the SREBP1 gene promoter in Hs578T cells expressing control vector, WT FLAD1 and WT FLAD1 treated with 80 µM GSK-LSD1 for 24 h were determined by ChIP-qPCR assay. n Schematic model of proposed mechanisms of the FLAD1/LSD1/SREBP1 signaling pathway. Graph bars represent mean ± SEM, and P value was calculated by two-tailed Student’s t-test. Results in (f, i, l, m) represent biologically independent experiments of n = 3. b–e, g, h, j n = 3 independent experiments, a representative example is shown. Source data are provided as a Source Data file.

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