Fig. 3: MTA1 regulates tumor suppressor, EMT, and stemness pathways.

A Heatmap of known EMT-associated-and tumor stemness-associated genes from differential gene analysis of shMTA1 and shSCR cells RNA sequencing. B RT-qPCR analysis of selected tumor suppressor genes (MTA3, TRIM21, ULK1, LIFR, PRKACB, TNF, ATP6V0D2, BASP1, DGAT2, and ITGA7) after overexpression of MTA1 in MCF-7 cells or knockdown of MTA1 in MDA-MB-231 cells. mRNA expression levels of the target genes were normalized to that of GAPDH levels. C qChIP analysis of indicated genes in MDA-MB-231 cells. GAPDH was used as internal control. D MDA-MB-231 cells were infected with shSCR and shMTA1 lentiviruses. qChIP analysis of tumor transcription factor recruitment was performed using an MTA1 antibody, with GAPDH as an internal control. E Western blotting demonstrated that overexpression MTA1 downregulated MTA3 and TRIM21 protein expression levels in MCF-7 cells. The protein expression levels of MTA3 and TRIM21 increase in MDA-MB-231 cells after stably transfected with shMTA1. F Primer pairs #1–8 were synthesized to cover the promoter region of MTA1, and a qChIP-based promoter walking experiment was performed using MCF-7 cells (up). Primer pairs #1–8 were synthesized to cover the promoter region of MTA3, and a qChIP-based promoter walking experiment was performed using MDA-MB-231 cells (bottom). G Western blotting results for epithelial, mesenchymal, and stemness markers after the simultaneous knockdown of MTA1 and MTA3 in MDA-MB-231 and MCF-7 cells. H Schematic overview of the transcriptionally regulatory between MTA1 and MTA3. Error bars represent the mean ± SD in B–D, F. *p < 0.05, **p < 0.01; two-tailed unpaired t-test.