pathtodependency2ko

Pathtodependency2ko is a computational method used in systems biology and network analysis to identify minimal pairs of perturbations that disrupt a defined dependency between components in a biological network. The name merges the concept of a path-to-dependency analysis with the two-knockout (2KO) perturbation idea, where two genes or proteins are simultaneously disrupted to affect a functional pathway.

Concept and approach: In a biological interaction network, nodes represent genes, proteins, or metabolites, while edges denote regulatory or physical interactions. A dependency path links a source node to a target node through intermediate steps. pathtodependency2ko searches for pairs of nodes whose simultaneous disruption intercepts all such paths, breaking the required dependency.

Algorithmic methods: The method builds a directed or undirected graph, identifies plausible source-to-target paths, and seeks node pairs whose removal intersects every path. This often involves minimum 2-node cut calculations, heuristic pruning, and permutation testing to prioritize biologically plausible knockouts.

Applications: It supports synthetic lethality studies in cancer, identification of combinatorial drug targets, and analyses of network robustness. By focusing on two perturbations, it provides a tractable starting point for experimental validation while acknowledging higher-order interactions may exist.

Limitations and considerations: Success depends on the completeness and context relevance of the interaction network. Predictions require experimental validation, and two-node analyses may overlook alternative redundant pathways. Computational complexity scales with network size and path multiplicity.

See also: synthetic lethality, knockout, network analysis, path analysis.