Table 1.

Summary of results for the applied virtual screening methods. The various molecular similarity methods using the PRL-3 inhibitor thienopyridone [17] as a search template are listed (the first row refers to all ligand-based methods as a whole). Dockings were performed with the PRL-3 docking models docking1-1v3a, docking1-hmod and docking2-1v3a, as explained in the text. For the purpose of this study, we regarded as a hit a tested compound with an IC₅₀ value of about 100 μM or less against PRL-3 using DiFMUP as substrate. The IC₅₀ values of these five hits were 31, 48, 58, 102 and 108 μM (four additional inhibitors with potencies less than 200 μM were found but not further considered as their IC₅₀ value was deemed too high to be promising for potential optimization). Hit rates are provided to quantify the performance of each method on PRL-3.

In silico method	Hit rate (%)	# hits within tested compounds	# tested compounds
Similarity screens (total)	12.2	5	41
USR	15.4	2	13
MACCS	28.6	2	7
UFSRAT	8.3	1	12
ROCS	0	0	9
Docking1-1v3a	0	0	9
Docking1-hmod	0	0	10
Docking2-1v3a	0	0	27