Abstract: Anti-tumor drug remains the primary treatment for most disseminated cancers. However, the response to anti-tumor drug is often transient, and development of resistance is one of the most significant obstacles to effective cancer therapy. The molecular mechanisms underlying cancer resistance are only partially understood. In addition to genetic changes, reversible transcriptional states controlled by epigenetic are believed to play a role in generating dynamic drug-resistance. These observations have important clinical consequences as they provide an opportunity for exploring a more efficient epigenetic therapy as well as potential biomarkers mediating non-invasive monitoring.

Key words: epigenetics, anti-tumor drug, drug resistance