PIK-93 is the first potent, synthetic PI4K inhibitor with IC50 of 19 nM; inhibits PI3Kα with IC50 of 39 nM.

PI4K:19 nM, PI3Kα:39 nM

0.5 μM-1 μM PIK-93作用于分化的HL60细胞,损害用f-Met-Leu-Phe处理而形成的聚集的稳定性。在COS-7细胞中,PIK-93（250 nM）有效地消除了高尔基体中CERT-PH结构域和FL-Cer的积累。在T6.11细胞中,300 nM PIK-93降低Carbachol诱导的TRPC6移位到质膜上和Ca2+进入。相同浓度PIK-93也明显抑制[3H]丝氨酸标记的内源性神经酰胺转变为神经鞘磷脂。这些说明了PI4KIIIβ在内质网和高尔基体中的神经酰胺转移时具有重要作用,以及有效调节鞘磷脂的合成。一项研究显示,PIK-93具有抗肠道病毒功能,抑制脊髓灰质炎病毒和丙型肝炎病毒复制,EC50分别为0.14 μM和1.9 μM。PIK-93有效抑制PI3Kγ和PI4KIIIβ,IC50分别为16 nM和19 nM。PIK-93也抑制其他PI3Ks成员,包括PI3Kα,β和δ,IC50分别为39 nM,0.59 μM和0.12 μM。而PIK-93对其他激酶几乎没有抑制效果,即使浓度为10 μM。

Assay of PI3Ks: IC50 values are measured using a standard TLC assay for lipid kinase activity. Kinase reactions are performed by preparing areaction mixture containing kinase, PIK-93 (2% DMSO final concentration), buffer (25 mM HEPES, pH 7.4, 10 mM MgCl2), and freshly sonicated phosphatidylinositol (100 μg/ml). Reactions are initiated by the addition of ATP containing 10 μCi of γ-32P-ATP to a final concentration 10 or 100 μM, and allowed to proceed for 20 min at room temperature. For TLC analysis, reactions are then terminated by the addition of 105 μL 1N HCl followed by 160 μL CHCl3:MeOH (1:1). The biphasic mixture is vortexed, briefly centrifuged, and the organic phase transferred to a new tube using a gel loading pipette tip precoated with CHCl3. This extract is spotted on TLC plates and developed for 3 hours–4 hours in a 65:35 solution of n-propanol:1M acetic acid. The TLC plates are then dried, exposed to a phosphorimager screen, and quantitated. Kinase activity is typically measured at 10–12 concentrations of PIK-93 representing two-fold dilutions from the highest concentration of 100 μM.

For actin staining, dHL60 cells are preincubated in suspension with PIK-93 or vehicle for 40 min, centrifuged for 5 min at 2000 rpm at room temperature in a J6-B centrifuge, resuspended in mHBSS containing the respective agent at the same concentration, allowed to stick to fibronectin-covered coverslips, and subjected to stimulation with a uniform concentration of 100 nM f-Met-Leu-Phe (fMLP) for 3 min. Cellsare fixed in 3.7% PFA and stained with 10 units/mL rhodamine-phalloidin for 15 min.(Only for Reference)