The role of DNA methylation and DNA methyltransferases (DNMTs) as potential biomarker and therapeutic target in non-small cell lung cancer (NSCLC).

Lung cancer as the second most death cancer reported cases is becoming a major threat to the global healthcare system. With the different subtypes of lung cancer and their limited therapy options due to the lack of targetable genes, rising cases of treatment resistance further complicate the management. The majority of the reported lung cancer cases are categorised as non-small cell lung cancer (NSCLC) which is highly associated with tobacco smoking. Tumorigenesis and cancer progression have also been associated with epigenetics. Epigenetics is responsible for cancer gene regulation and its reversible mechanisms attract the current trend of cancer management research. One of the most studied mechanisms is DNA methylation which can influence the cancer gene transcription outcomes. The enzyme, DNA methyltransferases (DNMTs) play a role in regulating the whole process of DNA methylation. Thus, abnormalities in DNMTs can lead to aberrant methylation patterns which then disturb the gene regulation and cellular functions as a whole. In this review, NSCLC subtypes are discussed with the current research trend of studies involving DNA methylation mechanism as a potential diagnostic and prognostic cancer biomarker. As DNMTs expression influences the methylation pattern, our review also outlined the abnormal pattern of DNMTs and its potential therapeutic target for NSCLC to restore the aberrant gene regulation and produce a better prognosis.