Epigenetic regulation−The guardian of cellular homeostasis and lineage commitment

Stem cells constitute the source of cells that replenishes the worn out or damaged cells in our tissue and enable the tissue to carry out the destined function. Tissue-specific stem cells are compartmentalized in a niche, which keeps the stem cells under quiescent condition. Thus, understanding the molecular events driving the successful differentiation of stem cells into several lineages is essential for its better manipulation of human applications. Given the developmental aspects of the cell, the cellular function is greatly dependent on the epigenomics signature that in turn governs the expression profile of the cell. The stable inheritance of the epigenome is crucial for the development, modulation, and maintenance of the cell and its complex tissue-specific function. Emerging evidence suggesting that stem cell chromatin comprises a specialized state in which self-renewing genes and its downstream lineage-specific genes are kept paralleled poised for activation. Thus, the epigenetic regulatory network and pathway dictate lineage commitment and differentiation. It mainly modifies the chromatin landscape to facilitate euchromatin and heterochromatin architecture, which in turn alters the accessibility of transcription factors to the gene loci. DNA methylation and histone marks are the two widely studied epigenetic modifications regulating the transcriptome profile of a specific lineage. Abnormalities in the epigenetic landscape lead to diseases or disorders. Here, we emphasize the prominence of the epigenetic network and its regulation in normal tissue functioning and in the diseased state. Furthermore, we highlighted the emerging role of epigenetic modifiers in lineage differentiation and epigenetic markers as novel druggable targets for cancer therapy.