RESUMO
BACKGROUND: Apoptosis is a critical process in endothelial cell (EC) biology and pathology, which has been extensively studied at protein level. Numerous gene expression studies of EC apoptosis have also been performed, however few attempts have been made to use gene expression data to identify the molecular relationships and master regulators that underlie EC apoptosis. Therefore, we sought to understand these relationships by generating a Bayesian gene regulatory network (GRN) model. RESULTS: ECs were induced to undergo apoptosis using serum withdrawal and followed over a time course in triplicate, using microarrays. When generating the GRN, this EC time course data was supplemented by a library of microarray data from EC treated with siRNAs targeting over 350 signalling molecules.The GRN model proposed Vasohibin-1 (VASH1) as one of the candidate master-regulators of EC apoptosis with numerous downstream mRNAs. To evaluate the role played by VASH1 in EC, we used siRNA to reduce the expression of VASH1. Of 10 mRNAs downstream of VASH1 in the GRN that were examined, 7 were significantly up- or down-regulated in the direction predicted by the GRN.Further supporting an important biological role of VASH1 in EC, targeted reduction of VASH1 mRNA abundance conferred resistance to serum withdrawal-induced EC death. CONCLUSION: We have utilised Bayesian GRN modelling to identify a novel candidate master regulator of EC apoptosis. This study demonstrates how GRN technology can complement traditional methods to hypothesise the regulatory relationships that underlie important biological processes.
Assuntos
Apoptose/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Endoteliais/citologia , Redes Reguladoras de Genes/genética , Teorema de Bayes , Proteínas de Ciclo Celular/deficiência , Biologia Computacional , Células Endoteliais/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Modelos Genéticos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genéticaRESUMO
The use of a caged G-quadruplex ligand allows for transcriptional control of quadruplex-containing genes using UV light as an external trigger. An important oncogene, SRC, involved in the initiation and proliferation of epithelial tumours is shown to be significantly downregulated in cells treated by the caged ligand in synergy with UV light treatment.