Epigenetic mechanisms in human cancer

Epigenetics is the field that studies the changes that regulate gene expression without affecting the coding sequence of DNA, such as changes in DNA methylation and postranslational modifications at the histone tails. Using chromatin immunoprecipitation (ChIP) scientists are able to study which proteins (histones or transcription factors) bind to DNA at a specific locus. ChIP becomes a powerful tool when it is coupled to sequencing or DNA microarrays, a technique known as ChIP-chip, enabling the study of all possible binding sites for any protein across the entire genome. A miniaturized micro-ChIP method was developed in order to perform these experiments in limited amount of tissue. DNA methylation analysis was included as well resulting in the liver cancer methylome. This work presents an effective combinatorial methodology for genome-scale characterization of tumors, allowing the identification of the principal mechanisms responsible for the liver cancer transcriptome. I hope this work will be useful to other scientists in their quest at other cancer types or diseases by assisting in the design of therapeutic treatments and to identify novel tumor markers.