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Phenotypic (non-genetic) heterogeneity has significant implications for the development and evolution of organs, organisms, and populations. Recent observations in multiple cancers have unraveled the role of phenotypic heterogeneity in driving metastasis and therapy recalcitrance. However, the origins of such phenotypic heterogeneity are poorly understood in most cancers. Here, we investigate a regulatory network underlying phenotypic heterogeneity in small cell lung cancer, a devastating disease with no molecular targeted therapy. Discrete and continuous dynamical simulations of this network reveal its multistable behavior that can explain co- existence of four experimentally observed phenotypes. Analysis of the network topology uncovers that multistability emerges from two teams of players that mutually inhibit each other, but members of a team activate one another, forming a ‘toggle switch’ between the two teams. Deciphering these topological signatures in cancer-related regulatory networks can unravel their ‘latent’ design principles and offer a rational approach to characterize phenotypic heterogeneity in a tumor. [ABSTRACT FROM AUTHOR]

The significant insights into the immunobiology of central nervous system (CNS) and brain tumor have opened up the feasibility of applying 'Immunotherapy' as an alternative to the poor prognosis of malignant brain tumor with conventional therapeutic approaches. Though cytokines like IL-2 and IFN-gamma used against glioma showed some favorable results by eliciting Th1 type immune response, a proper immunotherapeutic agent is still to be searched for. Sheep erythrocyte (SRBC), a corpuscular antigen showed a better therapeutic efficacy in terms of enhanced survival and augmentation of cell mediated immunity (CMI) in a glioma model developed by chemical carcinogen ethyl nitrosourea. Histological findings revealed most efficient glioma rejection in SRBC and combination biological response modifier (BRM) treated groups. Simultaneously E-rosetting, cytotoxicity of lymphocytes, phagocytosis and antigen presenting capacity of myeloid cells established the better therapeutic efficacy of SRBC alone than other BRMs viz. IL-2 and IFN-gamma. Even the effect of combination therapy of different BRMs showed marginal differences in facilitating glioma reduction than the single use of SRBC. These findings emphasized the application of SRBC as an exogenous BRM having the potential as a rational therapeutic adjunct against glioma.