Prediction of Drug-Target Interactions for Drug Repositioning Only Based on Genomic Expression Similarity
Figure 4
The rationale and performance of DTI prediction model.
(A) If a target has its ligand-binding well characterized by CMap, we expect the potential ligands to show higher BAES to benchmark ligands (red colored connections) than random compounds do (grey colored connections), i.e. the LOI of ligands should excel the overall background of CMap. (B) For the cross validation of PPAR-γ, the area under ROC curve reaches 0.86, with the 95% confidence interval (i.e. the grey colored shape) ranging from 0.74 to 0.99. The LOI corresponding to 90 percent specificity is set as the threshold to discriminate positive and negative sets. Thus, only 10 percent of the negative set is above the threshold, i.e. there would be 130 false positive (FP) and 1170 true negative (TN) compounds. Meanwhile, 67 percent of the positive set is above the threshold, so there would be 6 true positive (TP) and 3 false negative (FN) compounds. The statistical significance of such enrichment (odds ratio = 18) is determined by Fisher's exact test (p = 7.31×10−5).