Cancer cells, regardless of tissue of origin and genetic background, exhibit hallmark features consistent with breakdown in regulatory functions associated with multicellularity. Because they affect highly evolved processes like cell differentiation and extracellular signaling, such abnormalities suggest that tumorigenesis reflects the activation of ancient genes that predate the emergence of multicellular organisms. However, evidence supporting this premise is lacking.

Using data from the Cancer Genome Atlas, researchers combined expression analysis with phylogenetic and interaction data to investigate the relationship between changes in gene expression in tumors and the evolutionary histories of those genes for seven types of solid tumors.

Gene age and expression level in tumors were closely related, exhibiting patterns in processes central to cancer that implied both a history of selection and active upregulation during malignant transformation.

The authors found that highly conserved genes from unicellular organisms are preferentially expressed in tumors at the expense of coordinated function between unicellular and multicellular components of gene regulatory networks. The study points to 12 highly connected genes as potential drivers of tumorigenesis, according to the authors.

http://www.pnas.org/content/early/2017/05/04/1617743114