Abhimanyu K. Jha, Shailesh Kumar, Mohsen Nikbakht, Vishal Sharma, Jagdeep Kaur
Epigenetics refers to the change in gene expression without the change in the sequence of the gene. Epigenetics includes alternate phenotypic states th at are not based on differences in genotype, but ar e generally stably maintained during cell division an d are potentially reversible. A much more expanded view of epigenetics involves multiple mechanisms in teracting to collectively establish alternate state s of chromatin structure, histone modification, assoc iated protein composition and transcriptional activity. Chromatin structure is not fixed. Instead , chromatin is a dynamic identity and is subject to extensive developmental, environmental and age-asso ciated remodeling. In some cases, this remodeling appears to counter the ageing and age-as sociated diseases, such as cancer, and extend organismal lifespan. Advances in our understanding of chromatin structure, histone modification, transcriptional activity, promoter hypermethylation and global hypomethylation resulted in an increasingly integrated and expanded view of epigen etics. The study of epigenetics reveals how patterns of gene expression are passed from one cel l to its descendants, how gene expression changes during the differentiation of one cell type into another, and how environmental factors can change the way genes are expressed. There are far-r eaching implications of epigenetic research for human biology and diseases, including our understan ding of cancer and ageing. Due to these developments, epigenetic therapy is expanding to in clude combinations of histone deacetylase inhibitors and DNA methyltransferase inhibitors. Th is review encompasses the different types of epigenetic changes, the interplay among them and th e implications of these epigenetic changes in relation to cancer and ageing. Besides this, the de velopment and perspective of epigenetic therapy has also been discussed in brief.
Share this article