title: Minimally perturbing a gene regulatory network to avoid a disease phenotype: the glioma network as a test case.
abstract: BACKGROUND
  Mathematical modeling of biological networks is an essential part of Systems Biology. Developing and using such models in order to understand gene regulatory networks is a major challenge.
  
  
  RESULTS
  We present an algorithm that determines the smallest perturbations required for manipulating the dynamics of a network formulated as a Petri net, in order to cause or avoid a specified phenotype. By modifying McMillan's unfolding algorithm, we handle partial knowledge and reduce computation cost. The methodology is demonstrated on a glioma network. Out of the single gene perturbations, activation of glutathione S-transferase P (GSTP1) gene was by far the most effective in blocking the cancer phenotype. Among pairs of perturbations, NFkB and TGF-beta had the largest joint effect, in accordance with their role in the EMT process.
  
  
  CONCLUSIONS
  Our method allows perturbation analysis of regulatory networks and can overcome incomplete information. It can help in identifying drug targets and in prioritizing perturbation experiments.
authors.affiliation: Tel-Aviv University, Haim Levanon St,, 69978, Tel-Aviv, Israel. guykarle@post.tau.ac.il
authors.forename: Guy
authors.initials: G
authors.lastname: Karlebach
authors.forename: Ron
authors.initials: R
authors.lastname: Shamir
mesh_terms: D000465:Algorithms; D000818:Animals; D001932:Brain Neoplasms / Q000235:genetics*; D003198:Computer Simulation; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D005818:Genetic Engineering / Q000379:methods; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005910:Glioma / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D009363:Neoplasm Proteins / Q000235:genetics*; D010641:Phenotype; D015398:Signal Transduction / Q000235:genetics*
chemical_list: D009363:Neoplasm Proteins