Abstract: In nonsmall cell lung cancer (NSCLC), a major characteristic is the abnormal methylation of some certain genes. The hypomethylation of protooncogene has the potential to promote carcinogenesis and the formation of neoplasm may also be induced by the hypermethylation of tumor suppressor genes. Meanwhile, the balance between histone acetylation and deacetylation is closely connected to the tumorigenesis. While the histone acetyltransferases can directly acetylate genes related to proliferation, causing cell growth and transformation, histone deacetylase will also alter the level of acetylation of certain proteins, and eventually affect NSCLC. Hence, these abnormal epigenetic modifications play a fundamental role in the formation and development of NSCLC.

Key words: Epigenesis, genetic, DNA methylation, Histones, Acetylation, Carcinoma, nonsmallcell lung