Pluto Bioinformatics

GSE134147: MUC1-C ACTIVATES THE NURD COMPLEX IN DEDIFFERENTIATION OF TRIPLE-NEGATIVE BREASTCANCER CELLS

Bulk RNA sequencing

The NuRD chromatin remodeling and deacetylation complex, which includes MTA1, MBD3, CHD4 and HDAC1 among other components, is of importance for development and cancer progression. The oncogenic MUC1-C protein activates EZH2 and BMI1 in the epigenetic reprogramming of triple-negative breast cancer (TNBC) cells. However, there is no known link between MUC1-C and chromatin remodeling complexes. The present studies demonstrate that MUC1-C binds directly to the MYC HLH/LZ domain. In turn, we identified a previously unrecognized MUC1-CMYC pathway that regulates the NuRD complex. We show that MUC1-C/MYC complexes selectively activate the MTA1 and MBD3 genes and posttranscriptionally induce CHD4 expression in basal- and not luminal-type BC cells. The results further show that MUC1-C forms complexes with these NuRD components on the ESR1 promoter. In this way, silencing MUC1-C (i) decreased MTA1/MBD3/CHD4/HDAC1 occupancy and increased H3K27 acetylation on the ESR1 promoter, and (ii) induced ESR1 expression and downstream estrogen response pathways. We also demonstrate that targeting MUC1-C and these NuRD components induces expression of FOXA1, GATA3 and other markers associated with the luminal phenotype. These findings and results from gain-of-function studies support a model in which MUC1-C activates the NuRD complex in driving luminalbasal dedifferentiation and plasticity of TNBC cells. SOURCE: Qiang Hu (Qiang.Hu@RoswellPark.org) - Roswell Park Cancer Institute