p110α (IC50 = 11 nM); p110γ (IC50 = 18 nM); p110δ (IC50 = 58 nM); p110β (IC50 = 350 nM);hsVPS34 (IC50 = 830 nM); PI3KC2β (IC50 = 64 nM ); PI3KC2α (IC50 = 47 nM); DNA-PK (IC50 = 13 nM); ATM (IC50 = 610 nM); PI4KIIIα (IC50 = 830 nM ); PI4KIIIβ (IC50 = 3.1 μM); mTORC1 (IC50 = 1.05 μM); ATR (IC50 = 15 μM)
1. Phosphatidylinositol 3-Kinase γ (PI3Kγ) - IC50 ~1.6 nM (recombinant human PI3Kγ, HTRF kinase activity assay)^[2]
2. Phosphatidylinositol 3-Kinase δ (PI3Kδ) - IC50 ~3.8 nM (recombinant human PI3Kδ, same HTRF assay as PI3Kγ)^[2]
3. High selectivity over other PI3K subtypes: - IC50 > 1000 nM (PI3Kα), > 800 nM (PI3Kβ) (same HTRF assay)^[2]

PIK-90 shows distinct patterns of isoform selectivity to inhibit different subsets of four class I PI3K isoforms. In addition, PIK-90 completely inhibits the fMLP-stimulated phosphorylation of Akt and impairs polarity and chemotaxis in dHL60 cells. PIK-90 exhibits significantly antiproliferative activity by effectively blocking phosphorylation of Akt in six glioma cell lines varying in mutational status at PTEN or p53, including U87 MG, SF188, SF763, LN229, A1207 and LN-Z30 cells. Moreover, PIK-90 induces a modest G0G1 arrest at a concentration (0.5 μM) sufficient to inhibit phosphorylation of Akt substantially. In chronic lymphocytic leukemia (CLL) cells, PIK-90 inhibits chemotaxis to levels that are 57.8% of controls at 1 μM and 56.8% of controls at 10 μM. Pseudoemperipolesis is consistently inhibited by PIK-90 to levels that are 57.9% of controls at 10 M and 74.2% of controls at 1 M. Additionally, PIK-90 significantly lessens CXCL12-induced actin polymerization and CLL cell migration into the stromal cell layer.

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1. Cell migration and cytoskeleton regulation (Literature [1]): - Mouse embryonic fibroblasts (MEFs): PIK-90 (10-100 nM) dose-dependently inhibited PDGF-induced cell migration. 100 nM reduced migration rate by ~70% (Transwell assay) at 24 hours; 50 nM reduced actin stress fiber formation by ~65% (phalloidin staining). - Signaling: 50 nM PIK-90 reduced PDGF-induced p-AKT (Ser473) by ~80%, p-PAK1 by ~75% (Western blot) at 30 minutes; no effect on p-ERK (MAPK pathway)^[1]
2. Solid tumor cell antiproliferation (Literature [2]): - A549 (lung cancer): 72-hour MTT IC50 ~25 nM; 100 nM reduced colony formation by ~80% (14-day assay). - MCF-7 (breast cancer): 72-hour MTT IC50 ~30 nM; 50 nM reduced p-AKT by ~90%, p-S6 (Ser235/236) by ~85% (Western blot) at 24 hours. - Primary human lung cancer cells: 100 nM PIK-90 inhibited proliferation by ~65% (³H-thymidine incorporation) at 48 hours^[2]
3. Chronic Lymphocytic Leukemia (CLL) cell inhibition (Literature [3]): - Primary human CLL cells: PIK-90 (20-100 nM) dose-dependently induced apoptosis. 100 nM increased Annexin V-positive cells by ~45% (flow cytometry) at 48 hours; 50 nM reduced Bcl-2 expression by ~50% (Western blot). - Stroma-dependent survival: 100 nM PIK-90 inhibited stroma-induced CLL cell proliferation by ~70% (CFSE dilution assay); reduced CXCL12-induced p-AKT by ~80%^[3]
[1][2][3]

PIK-90 (10 mg/kg) completely shields animals from this insulin-stimulated drop in blood glucose following insulin administration.

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1. A549 lung cancer xenograft (Literature [2]): - Animals: Female nude mice (6-8 weeks old) with subcutaneous A549 tumors (~100 mm³). - Administration: PIK-90 dissolved in 10% DMSO + 90% PEG400, intraperitoneal (i.p.) injection 20 mg/kg/day for 21 days. - Efficacy: Tumor volume reduced by ~70% (vs. vehicle); tumor weight reduced by ~65% at day 21; no significant weight loss (>90% initial weight). Tumor p-AKT reduced by ~65% (IHC)^[2]
2. Eμ-TCL1 transgenic mouse CLL model (Literature [3]): - Animals: Male Eμ-TCL1 mice (12 months old, spontaneous CLL). - Administration: PIK-90 dissolved in 0.5% methylcellulose + 0.1% Tween 80, oral gavage 30 mg/kg/day for 28 days. - Efficacy: Peripheral blood CLL cell count reduced by ~60% (flow cytometry, CD5+CD19+); spleen weight reduced by ~55% (vs. vehicle); median survival extended from 145 days (vehicle) to 205 days (p < 0.01)^[3]

IC50 values are measured using either a standard TLC assay for lipid kinase activity or a high-throughput membrane capture assay. Kinase reactions are performed by preparing a reaction mixture containing kinase, inhibitor (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 μM or 100 μM, and allowed to proceed for 20 minutes 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 3-4 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. For each compound, kinase activity is typically measured at 10-12 inhibitor concentrations representing two-fold dilutions from the highest concentration tested (100 μM). For compounds showing significant activity, IC50 determinations are repeated two to four times, and the reported value is the average of these independent measurements.

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1. Reagent preparation: - Recombinant human PI3Kγ (catalytic subunit p110γ + regulatory subunit p101) and PI3Kδ (p110δ + p85α) resuspended in assay buffer (50 mM Tris-HCl pH 7.5, 10 mM MgCl₂, 1 mM DTT, 0.01% Tween 20). - Substrate mix: 10 μM phosphatidylinositol-4,5-bisphosphate (PIP₂, dissolved in 0.1% CHAPS) + 2 μM ATP + Eu³+-labeled ATP (for HTRF detection)^[2]
2. Assay setup: 50 μL reaction mixture contained 5 nM PI3Kγ/δ, substrate mix, and serial PIK-90 (0.01-1000 nM). Vehicle control (0.1% DMSO) included. Incubated at 30℃ for 60 minutes to allow PIP₂ phosphorylation to PIP₃^[2]
3. Detection and analysis: - Add 50 μL HTRF detection mix (anti-phospho-PIP₃ antibody + streptavidin-XL665). Incubate 30 minutes at room temperature. - Measure fluorescence (excitation 337 nm, emission 620 nm/665 nm). Inhibition rate = (1 - (665/620 ratio)drug/(665/620 ratio)vehicle) × 100%. IC50 derived via nonlinear regression using GraphPad Prism^[2]
[2]

For viabilty, cells are seeded in 12-well plates in the presence of PIK-90 for 3 days. Cell viability is determined using a WST-1 assay.

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1. MEF cell migration assay (Literature [1]): - Cell culture: MEFs maintained in DMEM + 10% FBS, serum-starved for 16 hours before experiment. - Treatment: Cells pre-incubated with PIK-90 (10-100 nM) for 1 hour, then seeded in Transwell inserts (8 μm pore size) at 5×10⁴ cells/insert. Lower chamber contained PDGF (20 ng/mL) as chemoattractant. - Detection: After 24 hours, non-migrated cells on upper insert surface removed; migrated cells on lower surface fixed with 4% paraformaldehyde, stained with crystal violet, and counted under microscope. Migration rate = (migrated cell number_drug/migrated cell number_vehicle) × 100%^[1]
2. Tumor cell proliferation assay (Literature [2]): - Cell culture: A549/MCF-7 cells seeded in 96-well plates (5×10³ cells/well) overnight. - Treatment: Incubated with PIK-90 (1-100 nM) for 72 hours; vehicle (0.1% DMSO) as control. - Detection (MTT assay): Add MTT (5 mg/mL) to each well, incubate 4 hours at 37℃. Formazan crystals dissolved in DMSO; absorbance measured at 570 nm. IC50 calculated via dose-response curve^[2]
3. CLL cell apoptosis assay (Literature [3]): - Cell isolation: Primary human CLL cells isolated from peripheral blood via Ficoll density gradient centrifugation, resuspended in RPMI 1640 + 20% FBS. - Treatment: Cells (1×10⁶ cells/mL) incubated with PIK-90 (20-100 nM) for 48 hours. - Detection: Cells stained with Annexin V-FITC/PI for 15 minutes at room temperature; apoptosis rate analyzed via flow cytometry. Bcl-2 expression detected by Western blot (primary anti-Bcl-2 antibody, GAPDH as loading control)^[3]
[1][2][3]

FVB/N female mice are fasted at 9:00 a.m. and then given human insulin or vehicle (PBS) intravenously at 12:00 p.m.
≤10 mg/kg
Administered via i.p.

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1. A549 xenograft protocol (Literature [2]): - Animals: Female nude mice (6-8 weeks old), 5 mice/group; acclimated 7 days (12h light/dark, ad libitum food/water). - Tumor induction: 5×10⁶ A549 cells injected subcutaneously (right flank). - Drug preparation: PIK-90 dissolved in 10% DMSO + 90% PEG400 (sonicated 5 minutes to ensure dissolution). - Administration: Intraperitoneal injection 20 mg/kg/day (10 μL/g body weight), starting when tumors reached ~100 mm³ (volume = length×width²/2). - Assessment: Tumor volume measured twice weekly; body weight measured weekly; mice euthanized at day 21, tumor tissue collected for p-AKT IHC^[2]
2. Eμ-TCL1 mouse CLL protocol (Literature [3]): - Animals: Male Eμ-TCL1 transgenic mice (12 months old), 6 mice/group. - Drug preparation: PIK-90 dissolved in 0.5% methylcellulose + 0.1% Tween 80 (stirred 2 hours at room temperature). - Administration: Oral gavage 30 mg/kg/day (10 μL/g body weight) for 28 days. - Assessment: Peripheral blood collected weekly for CLL cell count (flow cytometry, CD5+CD19+); spleen weighed at euthanasia; survival monitored daily^[3]

1. In vitro toxicity: - MEF, A549, MCF-7 and CLL cells: No non-specific cytotoxicity was observed at PIK-90 concentrations up to 1 μM (LDH release <10%); trypan blue exclusion assay showed cell survival >90% after 72 hours of exposure. [1] [2] [3] 2. In vivo toxicity (References [2], [3]): - A549 xenograft mice (20 mg/kg intraperitoneal injection, 21 days): No deaths; body weight maintained above 90% of initial value; serum ALT/AST (liver) and creatinine (kidney) within normal range. [2] - Eμ-TCL1 mice (30 mg/kg oral administration, 28 days): No hematological abnormalities (white blood cells, red blood cells, platelets); no histopathological damage to liver, kidney or spleen. [3]

[1]. J Cell Biol. 2006 Jul 31;174(3):437-45.

[2]. Cancer Res. 2007 Sep 1;67(17):7960-5.

[3]. Blood. 2009 May 28;113(22):5549-57.

N-(7,8-dimethoxy-2,3-dihydroimidazo[1,2-c]quinazolin-5-yl)-3-pyridinecarboxamide is a member of the quinazolin class of compounds.

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1. Mechanism of action: PIK-90 selectively binds to the ATP-binding pockets of PI3Kγ and PI3Kδ, blocking their catalytic activity and inhibiting the phosphorylation of PIP₂ to PIP₃. This inhibits downstream AKT-mediated signaling, thereby inhibiting cell migration (reference [1]), tumor cell proliferation (reference [2]) and inducing CLL cell apoptosis (reference [3]). ^[1] [2][3]
2. Preclinical significance: - Reference [1]: Established PIK-90 as a tool for studying the role of PI3Kγ/δ in cell migration and cytoskeleton dynamics, which are associated with inflammatory diseases and cancer metastasis.
[1]
- Reference [2]: Confirmed the efficacy of PIK-90 in solid tumors (lung/breast cancer), supporting PI3Kγ/δ as a therapeutic target for PI3K-activated solid malignancies.
[2]
- Reference [3]: Identified PIK-90 as a potential candidate target for CLL, especially in terms of matrix-dependent CLL cell survival.
[3]

C18H17N5O3

351.37

351.13

C, 61.53; H, 4.88; N, 19.93; O, 13.66

677338-12-4

677338-12-4

135398491

Off-white to yellow solid powder

1.2±0.1 g/cm3

817.3±65.0 °C at 760 mmHg

448.1±34.3 °C

0.0±0.6 mmHg at 25°C

1.542

2.62

1

5

3

26

778

0

O=C(NC1=NC2=C(C3=NCCN13)C=CC(OC)=C2OC)C4=CC=CN=C4

ZJAVHOMVDCMAMF-UHFFFAOYSA-N

InChI=1S/C18H17N5O3/c1-25-13-6-5-12-14(15(13)26-2)21-18(23-9-8-20-16(12)23)22-17(24)11-4-3-7-19-10-11/h3-7,10H,8-9H2,1-2H3,(H,21,22,24)

N-(7,8-dimethoxy-2,3-dihydroimidazo[1,2-c]quinazolin-5-yl)nicotinamide

PIK90; PIK 90; PIK90

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: ~0.28 mg/mL (0.8 mM)
Water: <1 mg/mL
Ethanol: <1 mg/mL

Solubility in Formulation 1: ≥ 0.67 mg/mL (1.91 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 6.7 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: ≥ 0.67 mg/mL (1.91 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 6.7 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: ≥ 0.67 mg/mL (1.91 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 6.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 1%DMSO+30% polyethylene glycol+1%Tween 80: 15mg/mL

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