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Pirkl, M. F.-X.

Publications and source records attributed to Pirkl, M. F.-X..

2 recordsLinked to original sources

Identifying cancer pathway dysregulations using differential causal effects

Signaling pathways control cellular behavior. Dysregulated pathways, for example due to mutations that cause genes and proteins to be expressed abnormally, can lead to diseases, such as cancer. We introduce a novel computational approach, called Differential Causal Effects (dce), which compares normal to cancerous cells using the statistical framework of causality. The method allows to detect individual edges in a signaling pathway that are dysregulated in cancer cells, while accounting for confounding. Hence, artificial signals from, for example, batch effects have less influence on the result and dce has a higher chance to detect the biological signals. We show that dce outperforms competing methods on synthetic data sets and on CRISPR knockout screens. In an exploratory analysis on breast cancer data from TCGA, we recover known and discover new genes involved in breast cancer progression.

bioinformatics↗

Inferring perturbation profiles of cancer samples

MotivationCancer is one of the most prevalent diseases in the world. Tumors arise due to important genes changing their activity, e.g., when inhibited or over-expressed. But these gene perturbations are difficult to observe directly. Molecular profiles of tumors can provide indirect evidence of gene perturbations. However, inferring perturbation profiles from molecular alterations is challenging due to error-prone molecular measurements and incomplete coverage of all possible molecular causes of gene perturbations. ResultsWe have developed a novel mathematical method to analyze cancer driver genes and their patient-specific perturbation profiles. We combine genetic aberrations with gene expression data in a causal network derived across patients to infer unobserved perturbations. We show that our method can predict perturbations in simulations, CRISPR perturbation screens, and breast cancer samples from The Cancer Genome Atlas. AvailabilityThe method is available as the R-package nempi at https://github.com/cbg-ethz/nempi. Contactmartin.pirkl@bsse.ethz.ch, niko.beerenwinkel@bsse.ethz.ch

bioinformatics↗