A factor graph nested effects model to identify networks from genetic perturbations.
A factor graph nested effects model to identify networks from genetic perturbations.
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DOI:
10.1371/journal.pcbi.1000274
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发表时间:
2009-01
影响因子:
4.3
通讯作者:
Stuart, Joshua M.
中科院分区:
文献类型:
--
作者:
Vaske, Charles J.;House, Carrie;Luu, Truong;Frank, Bryan;Yeang, Chen-Hsiang;Lee, Norman H.;Stuart, Joshua M.
Complex phenotypes such as the transformation of a normal population of cells into cancerous tissue result from a series of molecular triggers gone awry. We describe a method that searches for a genetic network consistent with expression changes observed under the knock-down of a set of genes that share a common role in the cell, such as a disease phenotype. The method extends the Nested Effects Model of Markowetz et al. (2005) by using a probabilistic factor graph to search for a network representing interactions among these silenced genes. The method also expands the network by attaching new genes at specific downstream points, providing candidates for subsequent perturbations to further characterize the pathway. We investigated an extension provided by the factor graph approach in which the model distinguishes between inhibitory and stimulatory interactions. We found that the extension yielded significant improvements in recovering the structure of simulated and Saccharomyces cerevisae networks. We applied the approach to discover a signaling network among genes involved in a human colon cancer cell invasiveness pathway. The method predicts several genes with new roles in the invasiveness process. We knocked down two genes identified by our approach and found that both knock-downs produce loss of invasive potential in a colon cancer cell line. Nested effects models may be a powerful tool for inferring regulatory connections and genes that operate in normal and disease-related processes. Biological processes are the result of the actions and interactions of many genes and the proteins that they encode. Our knowledge of interactions for many biological processes is limited, especially for cancer where genomic alterations may create entirely novel pathways not present in normal tissue. Perturbing gene expression (for example, by deleting a gene) has long been used as a tool in molecular biology to elucidate interactions but is very expensive and labor intensive. The search for new genes that may participate can be a daunting “fishing expedition.” We have devised a tool that automatically infers interactions using high-throughput gene expression data. When a gene is silenced, it causes other genes to be switched on or off, which provide clues about the pathway(s) in which the gene acts. Our method uses the genomewide on/off states as a fingerprint to detect interactions among a set of silenced genes. We were able to elucidate a network of interactions for several genes implicated in metastatic colon cancer. Genes newly connected to the network were found to operate in cancer cell invasion in human cells, validating the approach. Thus, the method enables an efficient discovery of the networks that underlie biological processes such as carcinogenesis.
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影响因子:
7.5
作者:
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通讯作者:
Lees, Jacqueline A.
影响因子:
11.2
作者:
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Kumar, Rakesh
影响因子:
56.9
作者:
Brummelkamp, TR;Bernards, R;Agami, R
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Agami, R
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通讯作者:
Tyers M
DOI:
10.1073/pnas.95.13.7357
发表时间:
1998-06-23
影响因子:
11.1
作者:
de Nadal, E;Clotet, J;Ariño, J
通讯作者:
Ariño, J