Structural characteristics of gene networks for colon cancer

Genome forms gene networks in terms of complicated interactions to realize its functions. It is believed that the structure of a network dictates its functions. The comparison of the structures of gene networks for tissues with and without cancer can provide better understanding of formation and development of cancer on the molecular level. In this work, mutual information networks of cancer-related genes are constructed based on their expression profiles in colon tissues with and without cancer. The comparison and analysis of these network structures show that characteristic parameters, average degree, maximum ratio of community and modularity can distinguish the networks corresponding to normal tissues and diseased tissues. A method to find key genes is proposed that may have significant impacts on the formation of cancer from the network structure point of view. Here, eleven key genes are given. Our literature review shows that eight of these genes are closely related to the formation and development of colon cancer, leaving the other three genes open. Furthermore, we predict thirteen more genes that may play important roles in the formation of colon cancer according to the change of genes' degrees. These predictions call for empirical studies on these genes.