Epithelial-mesenchymal transition (EMT) is an integral biological process that plays a critical role in embryonic development, tissue regeneration and wound healing. Unfortunately, this process is frequently co-opted by cancer cells to facilitate tumour progression, metastasis and resistant toward therapy. Key transcription factors (TFs) such as SNAI1, SNAI2, ZEB1 and TWIST1 drives EMT by repressing epithelial markers and activating mesenchymal programs. Despite extensive research, the individual and cooperative role of these EMT-inducing TFs in the context of breast cancer remains poorly understood.
Elucidating the individual and combinatorial contribution of EMT-TFs in breast cancer will be crucial in advancing our understanding of tumour plasticity, metastatic potential and therapeutic resistance. To address this, we employed CRISPR/dCas9-KRAB to selectively repress the expression of SNAI1, SNAI2, ZEB1 and TWIST1 in TNBC cells. Our finding reveals that each TF regulates distinct signalling pathways, highlighting functional specificity and non-redundant role in EMT regulation. Interestingly, combined repression of all four EMT-TFs (4TF KD) revealed partial cross-regulatory interaction amongst themselves, suggesting a degree of mutual compensation within the EMT network.
Single-cell transcriptomic profiling of T11 syngeneic tumours indicates 4TF KD enhances immune cell infiltration, notably increasing the recruitment of T cells and natural killer cells compared to control. These findings point to a previously underappreciated immunodulatory role of EMT-TFs in shaping tumour microenvironment. Collectively, our findings indicate that the four keys EMT-TFs not only regulate epithelial plasticity but also influence immune cell dynamics.