Qualitative Analysis of Cancer Pathways with Transition and Place Invariants

It is of practical interest to know whether a biological network contains mass-preserving and state-preserving subnetworks. In a mass-preserving subnetwork, the total mass remains constant. In any state-preserving subnetwork, biological reactions bring the subnetwork back to an initial state. For instance, any reversible reaction forms a state-preserving subnetwork. In a large intricate biological network, it is rather cumbersome task to determine mass-preserving and state-preserving subnetworks. P-invariants and T-invariants are analysis methods that can be successfully used to determine mass-preserving and state-preserving subnetworks in a Petri net. In this thesis, the information is derived from the biological databases Reactome and KEGG as well as from the existing literature to date, to create rather detailed Petri net model of cancer pathway, and perform its qualitative analysis with P-invariants and T-invariants. Keywords: Biological network, Petri net, P-invariants, T-invariants.