Cored network biomarker of carcinogenesis from early and late stage bladder cancer samples

Cancers is the major cause of death around the world for a long time, and it occurs at DNA, RNA or protein level. In this study, we use the systems biology approach to construct the protein-protein interaction (PPI) networks for early and late stage bladder cancer. By comparing network of these two stage, core and specific network markers were identified by the intersection and distinction of key proteins. We identified 18 significant proteins(network marker) for the cored network and their carcinogenesis relevance values(CRVs) We construct the CPPIN and NPPIN network structures for both stage bladder cancer. We also identified 3388 cancer protein pairs and 3151 non-cancer protein pairs for the early stage bladder cancer, respectively. And build 634 cancer protein pairs and 1185 non cancer protein pairs for the late stage bladder cancer, respectively. Primary pathway analysis shows that proteins BRAC1 and CUL3 related to the function of cell growth, UBC should be only a housekeeping like protein because it does not involve in any important functions. More validation of these network markers by both literature and novel test set could help us reveal more mechanisms of bladder cancer in the future.