Fig. 6: HMGA1 promotes the transcription of FASN by enhancing the activity of SREBP1.

a Co-IP assay to detect the interaction between HMGA1 and FASN. b IGV plots of ATAC-seq peaks at the FASN locus in HMGA1 silencing and control CRC cells. Boxed is the TSS site. c, d Luciferase reporter assay to detect the effect of HMGA1 silencing (c) or overexpression (d) on the luciferase activity of the FASN promoter in CRC cells. e Correlation between FASN and SREBP1 in CRC patients from the TCGA database. f The samples derive from the same experiment but different gels for HMGA1, SREBP1, and another for β-actin were processed in parallel. β-actin served as loading control (The quantification provided under the blots is for the representative blot from 3 independent experiments). g Co-IP assay to detect the interaction between HMGA1 and SREBP1. The samples derive from the same experiment but different gels for HMGA1, and another for SREBP1 were processed in parallel (The quantification provided under the blots is for the representative blot from 3 independent experiments). h Immunofluorescence detection of HMGA1 and SREBP1 in CRC cells (Scale bar = 10 μm). i Luciferase reporter assay to detect the effect of SREBP1- overexpression or silencing on FASN transcription in HT-29 cells with or without HMGA1 knockdown. j Luciferase reporter assay to detect the effect of SREBP1 silencing or overexpression on HMGA1-activated FASN transcription in HT-29 cells. k Schematic illustration of the mutated promoter sites in pGL3-Basic-FASN reporter. Potential binding sites of SREBP1 in FASN promoter targeted by HMGA1 were mutated. l, m Luciferase reporter assay to detect the effect of SREBP1 binding sites mutated on HMGA1-activated FASN transcription in HMGA1-knocked down (l) or HMGA1-overexpressed (m) HT-29 cells. n Chromatin immunoprecipitation-qPCR assay (ChIP-qPCR) to verify that HMGA1 facilitated the binding of SREBP1 to the promoter of FASN in HT-29 cells. Data are presented as mean ± SD from 3 independent experiments. Statistical significance was determined by two-tailed unpaired t-test (c, d, i, j, l, m, n) or Pearson correlation coefficient (e). Ns, no statistical difference. IGV: integrative genomics viewer; ATAC-seq: assay for transposase accessible chromatin using sequencing; Co-IP: co-immunoprecipitation. Source data are provided as a Source Data file.