A research team has managed to characterize the complete epigenomes of the most frequent tumors, including those of colon, lung and breast cancer. The work, published in Oncogene, was led by Dr. Manel Esteller from IDIBELL and has involved researchers from the CNAG-CRG and other research institutions. The work represents a big step in the study of origin and progression of these tumors.

"Our analysis has allowed us to get a first unbiased look at all the tumor cell methylomes in solid tumors," says Dr. Manel Esteller. "We have not only found that many anti-cancer genes specifically slow down their activity in the cancer-affected organs, but we have also shown that there are other alterations in distant chromosomal regions that affect these organs, since in the three-dimensional world of the cells these sequences are in very close relative positions.”

Tumor inhibitory genes are known to lose their protective function if a certain chemical modification ("epi-genetic", that is, over the gene) is added. The main modification is usually a stop signal called DNA methylation. The human genome has 28 million candidate points to be regulated by this modification, but the most used techniques only allow researchers to study 1 million points.

At the same time, the research shows that sometimes there are long DNA fragments in which all neighboring genes undergo alterations of their chemical signals, as if they were blocks simultaneously altered in an epigenetic way.

Data obtained in this study is now publicly accessible and will allow new bioinformatic analyses that will surely provide more clues as to the origin and progression of these tumors.

Work of reference:

A DNA methylation map of human cancer at single base-pair resolution