Phospholipase D (PLD) is an enzyme which cleaves the head group from phospholipids, producing the second messenger phosphatidic acid. Two mammalian isoforms of PLD, PLD1 and PLD2, have been identified, with multiple splice variants of each. Although the two isoforms share structural and functional features, they are regulated differently and apparently subserve distinct roles. CAY10594 is a potent PLD2 inhibitor, both in vitro (IC50 = 140 nM) and in cells (IC50 = 110 nM). It is also effective as a PLD1 inhibitor at higher concentrations (IC50 = 5.1 μM in vitro, 1.0 μM in cells). CAY10594 strongly inhibits the invasive migration of breast cancer cells in transwell assays, suggesting that PLD might be a useful target in blocking tumor cell invasion.
