PI4KIIIβ (IC50 = 19 nM); PI4KIIIα (IC50 = 1.1 μM); p110γ (IC50 = 16 nM); p110α (IC50 = 39 nM); p110δ (IC50 = 120 nM); p110β (IC50 = 590 nM); PI3KC2β (IC50 = 140 nM); PI3KC2α (IC50 = 16 μM); hsVPS34 (IC50 = 320 nM); DNA-PK (IC50 = 64 nM); ATM (IC50 = 490 nM); mTORC1 (IC50 = 1.38 μM); ATR (IC50 = 17 μM)
PI4KIIβ (IC50 = 19 nM) [1]; PI3Kα and PI3Kγ (isoform-selective; complete inhibition of PI3Kγ-dependent Akt phosphorylation in cells at 0.5-1 μM) [2]
PIK-93 primarily targets phosphatidylinositol 4-kinase III beta (PI4KIIIβ). It is a potent inhibitor with an IC50 of 19 nM. It also inhibits PI3Kα with an IC50 of 39 nM and PI3Kγ with an IC50 of 16 nM. It shows weaker inhibition of PI3Kβ (IC50 = 0.59 μM) and PI3Kδ (IC50 = 0.12 μM). This dual PI4K/PI3K inhibitory profile makes it a valuable tool for studying the roles of these lipid kinases in cellular processes.

PIK-93 inhibits PI3Kγ and PI4KIIIβ, with IC50 values of 16 nM and 19 nM, respectively. PIK-93 also inhibits other members of PI3Ks, including PI3Kα, β, and δ, with IC50 values of 39 nM, 0.59 μM, and 0.12 μM, respectively. Even at a concentration of 10 M, PIK-93 has no discernible inhibitory effect on a panel of other kinases[1]. PIK-93 (0.5 M-1 M) decreases the consolidation and stability of the leading edge formed after treatment with uniform f-Met-Leu-Phe (fMLP) in differentiated HL60 (dHL60) cells. The fMLP-dependent accumulation of total F-actin is altered by PIK-93, but not in terms of quantity. PIK-93 increases cell turning frequency while decreasing the chemotactic index in fMLP gradients[2]. In COS-7 cells, PIK-93 (250 nM) successfully prevents the buildup of FL-Cer and the CERT-PH domain in the Golgi. The same concentration of PIK-93 also significantly reduces the ability of endogenous ceramide to transform into sphingomyelin when labeled with [3H]serine. These facts suggest that PI4KIIIβ plays a critical role in the regulation of spingomyelin synthesis as well as ceramide transport between the ER and Golgi[3]. PIK-93 (300 nM) inhibits net Ca2+ entry and carbachol-induced translocation of TRPC6 to the plasma membrane in T6.11 cells[4]. According to a recent study, PIK-93 has anti-enterovirus properties because it inhibits the replication of the poliovirus (PV) and the hepatitis C virus (HCV), with EC50 values of 0.14 µM and 1.9 µM, respectively[5].

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In dHL60 cells, treatment with PIK-93 (0.5-1 μM) completely inhibits fMLP-stimulated phosphorylation of Akt, a downstream effector of PIP3 [2].
PIK-93 impairs the consolidation and stability of the leading edge in response to uniform fMLP, causing formation of multiple transient pseudopods instead of a single stable front [2].
In chemotaxis assays using an fMLP gradient, PIK-93 substantially reduces the chemotactic index (CI) and triples the turning frequency of dHL60 cells, resulting in jerky trajectories with less persistent orientation toward the attractant source [2].
Despite these effects, PIK-93 does not significantly reduce total F-actin accumulation in response to fMLP [2].
In vitro, PIK-93 is a potent inhibitor of PI4KIIIβ and PI3K. It has been shown to play a crucial role in ceramide transport between the endoplasmic reticulum (ER) and the Golgi apparatus. Its activity is characterized by its ability to inhibit these lipid kinases, thereby affecting downstream signaling pathways. These in vitro studies confirm its mechanism of action and its utility as a chemical probe.

Specific in vivo data for PIK-93 are not detailed in the provided search results. As a research tool for studying PI4K and PI3K, its application is primarily in in vitro systems. However, its potent and selective inhibition of these kinases makes it a candidate for studying their roles in vivo, though such applications are not extensively documented. It is a research compound.

Standard TLC lipid kinase activity assays are used to calculate IC50 values. In order to carry out kinase reactions, a reaction 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) must be prepared. A final concentration of 10 or 100 µM is used to start the reactions, and they are then allowed to continue for 20 min at room temperature. The starting material for the reactions is ATP containing 10 µCi of γ-32P-ATP. The addition of 105 µL 1N HCl and 160 l of CHCl3:MeOH (1:1) then ends the reactions in preparation for TLC analysis. The organic phase is transferred to a new tube using a gel loading pipette tip that has been CHCl3-precoated after the biphasic mixture has been vortexed and briefly centrifuged. In a 65:35 solution of n-propanol:1M acetic acid, this extract is spotted on TLC plates and developed for 3–4 hours. Following drying, the TLC plates are shown to a phosphorimager screen and quantitated. As a two-fold dilution from the highest concentration of 100 μM, kinase activity is typically assessed at 10–12 concentrations of PIK–93.

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To determine the selectivity profile of PIK-93, in vitro kinase assays were performed using purified recombinant PI3K family members (15 enzymes) and other kinases. IC50 values were measured by incubating the kinase with varying concentrations of inhibitor and ATP, then quantifying product formation [1].
PIK-93 was found to potently inhibit PI4KIIβ with an IC50 of 19 nM in a lipid kinase assay using purified enzyme [1].
Crystal structures of PIK-93 bound to human p110γ were determined at 2.5-2.6 Å resolution. Recombinant human p110γ (residues 144-1102 with a C-terminal His6 tag) was purified from baculovirus-infected Sf9 cells. Crystals were grown at 17°C using sitting-drop vapor diffusion and soaked with inhibitor. Diffraction data were collected at a synchrotron radiation facility. The structure revealed hydrogen bonds between PIK-93 and Val882 (backbone amide and carbonyl) and Asp964 (side chain) [1].
Non-cellular enzyme assays for PIK-93 measure its inhibitory activity against PI4K and PI3K isoforms. These assays use recombinant kinases and specific lipid substrates to measure enzyme activity in the presence of varying inhibitor concentrations. IC50 values, such as 19 nM for PI4KIIIβ and 39 nM for PI3Kα, are determined in these cell-free biochemical systems.

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 appropriate agent at the same concentration, and then allowed to adhere to fibronectin-covered coverslips for 3 min. Rhodamine-phalloidin (10 units/mL) is used to stain cells that have been fixed in 3.7% PFA for 15 minutes.

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dHL60 cells were differentiated with DMSO and then preincubated in suspension with PIK-93 (0.5-1 μM, from a stock in DMSO, final DMSO 1.0%) for 40 minutes at room temperature. Cells were then centrifuged, resuspended in medium containing the same inhibitor concentration, allowed to adhere to fibronectin-coated coverslips, and stimulated with 100 nM fMLP for 3 minutes. After stimulation, cells were fixed with 3.7% paraformaldehyde and stained with rhodamine-phalloidin to visualize F-actin distribution [2].
For live-cell imaging of polarity, dHL60 cells expressing YFP-actin were preincubated with PIK-93 (1 μM) for 40 minutes, then plated on fibronectin-coated coverslips and stimulated with uniform 100 nM fMLP. Time-lapse images were acquired at 1-minute intervals using an inverted microscope with a cooled CCD camera [2].
Chemotaxis assays were performed using a micropipette containing fMLP to create a gradient. Cells preincubated with PIK-93 (0.5 μM) were placed on fibronectin-coated coverslips, and migration trajectories were tracked for 25 minutes. The chemotactic index (displacement in correct direction divided by path length) and turning frequency (deviations ≥60° between successive 2-minute vectors) were calculated [2].
To assess Akt phosphorylation, dHL60 cells were preincubated with PIK-93 (0.5-1 μM) for 40 minutes, then stimulated with 100 nM fMLP for 1 minute. Cell lysates were prepared and subjected to SDS-PAGE and Western blotting using anti-phospho-Akt (Thr308) antibody [2].
In vitro cell-based assays for PIK-93 are conducted using various cell lines to assess its effects on PI4K and PI3K signaling. Cells are treated with the compound, and downstream effects on lipid signaling, protein trafficking, and cell viability are assessed. These experiments help to elucidate the cellular functions of PI4K and PI3K.

Specific in vivo animal study protocols for PIK-93 are not detailed in the provided search results. As a research compound, it is primarily used in in vitro experiments to study lipid kinase biology. If used in vivo, it would likely be administered via intraperitoneal injection, but such applications are not extensively documented.

PIK-93 has a molecular weight of 443.51 g/mol and the CAS number 593960-11-3. It is soluble in DMSO. Its pharmacokinetic properties, such as half-life and bioavailability, are not extensively detailed in standard summaries. It is a research compound intended for laboratory use.

Comprehensive toxicological data for PIK-93 are limited as it is a research compound. It is intended for laboratory use only and is not for human consumption. As with all research chemicals, appropriate safety precautions should be taken when handling PIK-93.

[1]. A pharmacological map of the PI3-K family defines a role for p110alpha in insulin signaling. Cell. 2006 May 19;125(4):733-47

[2]. To stabilize neutrophil polarity, PIP3 and Cdc42 augment RhoA activity at the back as well as signals at the front. J Cell Biol. 2006 Jul 31;174(3):437-45

[3]. Phosphatidylinositol 4-kinase IIIbeta regulates the transport of ceramide between the endoplasmic reticulum and Golgi. J Biol Chem. 2006 Nov 24;281(47):36369-77

[4]. Involvement of phosphoinositide 3-kinase and PTEN protein in mechanism of activation of TRPC6 protein in vascular smooth muscle cells. J Biol Chem. 2012 May 18;287(21):17672-81

[5]. Phosphatidylinositol 4-kinase III beta is a target of enviroxime-like compounds for antipoliovirus activity. J Virol. 2011 Mar;85(5):2364-72

PIK-93 is one of the most polar inhibitors in the PI3K inhibitor panel with a calculated logP (CLogP) of 1.69 [1].
X-ray crystallography revealed that PIK-93 binds to p110γ in the ATP-binding pocket, making three hydrogen bonds: to the backbone amide and carbonyl of Val882 and to the side chain of Asp964. Unlike selective inhibitors such as PIK-39, PIK-93 adopts a flat conformation and projects into a deeper affinity pocket [1].
PIK-93 is a potent inhibitor of PI4KIIβ (IC50=19 nM) and represents the first potent synthetic PI4-kinase inhibitor, used to dissect the role of PI4-K isoforms in calcium signaling [1].
In neutrophil chemotaxis, PIK-93 (along with PIK-90) demonstrates that PI3Kγ is required for maintaining stable polarity by promoting both frontness (pseudopod stability) and backness (RhoA-dependent actomyosin contraction) via Cdc42 activation [2].
PIK-93 is a first-in-class, synthetic inhibitor of PI4K and a valuable chemical probe for studying lipid kinase biology. Its dual inhibition of PI4KIIIβ and PI3K makes it a useful tool for investigating the interplay between these two important lipid signaling pathways. It is not an approved drug and is exclusively available as a research compound.

C14H16N3O4S2CL

389.87754

389.027

C, 43.13; H, 4.14; Cl, 9.09; N, 10.78; O, 16.41; S, 16.45

593960-11-3

593960-11-3;

6852167

White to off-white solid powder

1.48 g/cm3

611.8ºC at 760 mmHg

323.8ºC

4.122

3

7

6

24

543

0

CC(NC1=NC(C)=C(S1)C2=CC=C(C(S(=O)(NCCO)=O)=C2)Cl)=O

JFVNFXCESCXMBC-UHFFFAOYSA-N

InChI=1S/C14H16ClN3O4S2/c1-8-13(23-14(17-8)18-9(2)20)10-3-4-11(15)12(7-10)24(21,22)16-5-6-19/h3-4,7,16,19H,5-6H2,1-2H3,(H,17,18,20)

N-(5-(4-chloro-3-(N-(2-hydroxyethyl)sulfamoyl)phenyl)-4-methylthiazol-2-yl)acetamide

PIK-93; PIK93; PIK 93

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: ~78 mg/mL (200.1 mM)
Water: <1 mg/mL
Ethanol: <1 mg/mL

Solubility in Formulation 1: ≥ 4.55 mg/mL (11.67 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 45.5 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (6.41 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (6.41 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 30% PEG400+0.5% Tween80+5%Propylene glycol:30mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)