The ghost in our genes.

The long-believed dichotomy between nature (genes) and nurture (environment) has suddenly been proved false by the emerging discovery of epigenetic molecular mechanisms that bridge these two aspects. To understand the link, structured scientific Review and meta-analysis of scientific publications in English language from past 10 years was done from various books, journals in central library and National Medical Library (NML) and various search engines like PubMed, Wiley, Google Scholar and Science Direct. Epigenetics is the study of acquired changes in chromatin structure that arise independently of a change in the underlying deoxyribonucleic acid (DNA) nucleotide sequence. Key components involved in epigenetic regulation are DNA methylation, histone modifications and micro ribonucleic acid (RNA). Epigenetics can be affected by various environmental factors like diet, drugs, stress, physical activity and addictive substances (tobacco & alcohol), which can modify the expression of genes associated with development, ageing and carcinogenesis. Epigenetics may also play a role in obesity, diabetes, cardiovascular, neurologic, autoimmune, reproductive, inflammatory and infectious diseases. Epigenetic modifications caused by tobacco chewing, smoking, diet, bacteria and inflammation affect the oral health and may contribute to aberrant epigenetic mechanisms as seen in oral pre-cancers and cancers. In the near future, epigenetic variations found in oral dysplastic cells can act as a molecular fingerprint for malignancies. DNA from oral rinses and buccal swabs can be used for determining both DNA methylation status and histone modifications. Epigenetic marks can prove to be novel markers for early diagnosis, prognosis and treatment in oral cancer as well as other oral diseases. We cannot change our genes, but we may soon be able to change the epigenetic marks on our genes! [ABSTRACT FROM AUTHOR]