GSE176558
Histone H3K27me3 demethylase act as a regulator of stemness in hypoxic cancer cells that are detached from extracellular matrix
Metastasis of cancer cells requires detachment from Extra Cellular Matrix (ECM) to seed cancer cells in a distant organ. Hypoxia is prevalent in this matrix detached cancer cells. Studies have established hypoxia as a chromatin modifier, as it transcriptionally controls expression of various histone demethylases (KDMs); therefore, we hypothesized that the presence of hypoxia could modulate the expression of KDMs in matrix detached cancer cells. Our study showed that in matrix detached cancer cells, both hypoxia and one of the hypoxia regulated H3K27me3 histone demethylase, namely KDM6B, was increased. Simultaneously, we found increased expression of stemness-associated genes, namely SOX-2, SOX-9, and CD44, in hypoxic matrix detached cancer cells. We discovered that KDM6B occupies the promoter region of both SOX-2 and CD44 to regulate their expression epigenetically. Targeting KDM6B reduces its occupancy, thereby expressing the stemness-related genes in matrix detached cancer cells. Further, we noticed increased occupancy of HIF1a promoter by KDM6B, suggesting its regulatory role in maintaining hypoxia in matrix detached cancer cells. This observation was further strengthened as we found a significant positive association between KDM6B and HIF1a in various cancer types. Overall, we found that matrix detachment modulates epigenome by inducing KDM6B activity to regulate the expression of stemness-related genes and hypoxia primarily through HIF1a in matrix detached conditions. KDM6B can be developed as a therapeutic target to eliminate matrix detached cancer cells bound for metastatic events Overall design: Examination whole transcriptome between ECM attached and ECM detached