Motivation: Synthetic lethality (SL) is a promising gold mine for the discovery of anti-cancer drug targets. Wet-lab screening of SL pairs is afflicted with high cost, batch-effect, and off-target problems. Current computational methods for SL prediction include gene knock-out simulation, knowledge-based data mining, and machine learning methods. Existing methods tend to assume that SL pairs are independent of each other, without taking into account their intrinsic correlation. Although several methods have incorporated genomic and proteomic data to aid SL prediction, these methods involve manual feature engineering that heavily relies on domain knowledge.
Results: Here we propose a novel graph neural network (GNN)-based model, named KG4SL, by incorporating knowledge graph message-passing into SL prediction. The knowledge graph was constructed using 11 kinds of entities including genes, compounds, diseases, biological processes, and 24 kinds of relationships that could be pertinent to SL. The integration of knowledge graph can help harness the independence issue and circumvent manual feature engineering by conducting message-passing on the knowledge graph. Our model outperformed all the state-of-the-art baselines in AUC, AUPR and F1. Extensive experiments, including the comparison of our model with an unsupervised TransE model, a vanilla GCN (graph convolutional network) model, and their combination, demonstrated the significant impact of incorporating knowledge graph into GNN for SL prediction.