Matrix stiffness modulates androgen response genes and chromatin state in prostate cancer (ATAC-seq)

The interplay between the extracellular matrix (ECM) and prostate cancer (PCa) tumor has been shown to increase ECM stiffness, correlating with more aggressive disease forms. However, the impact of ECM stiffness on the androgen receptor (AR), a primary PCa treatment target, remains elusive. Here, we aimed to explore whether matrix stiffness influences PCa progression, transcriptional regulation, chromatin state, and AR function in AR-positive PCa cells under varying ECM stiffness conditions. We utilized ATAC-seq and RNAseq in different ECM conditions and the SUC2 metastatic prostate adenocarcinoma patient dataset to understand the role of ECM stiffness on chromatin state, androgen response genes and to evaluate the effect of matrix stiffness on prostate cancer progression. Results showed that increased ECM stiffness elevated the expression of genes related to proliferation and differentiation. In contrast, androgen response genes were most induced in soft ECM conditions. Combining chromatin accessibility with transcriptomic results revealed that androgen response genes were more transcriptionally available in soft ECM conditions. Additionally, increased ECM stiffness upregulated genes associated with low overall survival in the SUC2 dataset. Taken together, our results indicate that high expression of hard matrix stiffness genes potentially promotes prostate cancer progression leading to more aggressive forms of the disease with poor survival rate.