GSE41479
Sorafenib inhibits epithelial-mesenchymal transition through an epigenetic-based mechanism in human lung epithelial cells
The epithelial to mesenchymal transition (EMT) has been well recognized for many decades as an essential early step in the progression of primary tumors towards metastases. Widespread epigenetic reprogramming of DNA and histone modifications tightly regulates gene expression and cellular activity during carcinogenesis, and epigenetic therapy has been developed to design efficient strategies for cancer treatment. As the first oral agent approved for the clinical treatment of cancer, sorafenib has significant inhibitory effects on tumor growth and EMT. However, a detailed understanding of the underlying epigenetic mechanism remains elusive. In this manuscript, we performed a ChIP-Seq assay to evaluate the activity of sorafenib on the genome-wide profiling of histone modifications. We demonstrate that sorafenib largely reverses the changes in histone modifications that occur during EMT in A549 alveolar epithelial cells. Sorafenib also significantly reduces the coordinated epigenetic switching of critical EMT-associated genes in accordance with their expression levels. Furthermore, we show that sorafenib potentiates histone acetylation by regulating the expression levels of histone-modifying enzymes. Collectively, these findings provide the first evidence that sorafenib inhibits the EMT process through an epigenetic mechanism, which holds enormous promise for identifying novel epigenetic candidate diagnostic markers and drug targets for the treatment of human malignancies. Overall design: To further explore the underlying epigenetic mechanisms of EMT regulation by sorafenib, we chose conventional markers of active euchromatin such as H3K9ac and H3K4me3, and contrasted their architecture with the repressive structures associated with H3K27me3 and H3K9me3. The profiling of these four selected histone modifications was performed using ChIP-seq on control, TGF-ß1-treated and sorafenib-treated cells. We further performed pair-wise comparisons among the three treatment conditions to assess the changes in the histone modifications within specific genomic regions during EMT.