PF-3758309

PF-3758309 is an inhbitor of PAK with IC50 of 1.3 nM for PAK4.

Signaling Pathways >> Cell Cycle/DNA Damage >> PAK

Signaling Pathways >> Cytoskeleton >> PAK

Research Areas >> Cancer

PAK4:18.7 nM (Ki)

PAK1:13.7 nM (Ki)

PAK5:18.1 nM (Ki)

PAK6:17.1 nM (Ki)

F-3758309 binds directly to PAK4 with an in vitro potency of 2.7-4.5 nM. PF-3758309 has similar enzymatic potency against the kinase domains of the other group B PAKs (PAK5, Ki=18.1±5.1 nM; PAK6, Ki=17.1±5.3 nM) and group A PAK1 (Ki=13.7±1.8 nM), but is less active against the other two group A PAKs (PAK2, IC50=190 nM; PAK3, IC50=99 nM). PAK4 phosphorylates GEF-H1 on a previously characterized serine residue 810 and is inhibited by PF-3758309 (IC50=1.3±0.5 nM). PF-3758309 also inhibits endogenous pGEF-H1 accumulation in HCT116 cells[1]. PF-3758309 is profiled for its growth-inhibitory activity in a panel of 92 tumor cell lines, half of which exhibits IC50 values of less than 10 nM[2]. The proliferation of A549 cells is affected at the treatment with lower dosage (1 μM) of PF-3758309[3].

PF-3758309 (7.5-30 mg/kg BID, p.o.) results in statistically significant tumor growth inhibition (TGI) in five models including HCT116 and A549 models. PF-3758309 (15 mg/kg BID, p.o.) is found to inhibit [3H]FLT uptake 32.5% in the HCT116 tumor xenografts by day 6. PF-3758309 treatment shows a significant increase in the apoptotic marker activated caspase 3 in HCT116 tumors[1]. PF-3758309 (25 mg/kg, p.o.) exhibits antiproliferative effects on cell line xenografts[4].

CCK-8 assay is performed to determine cell viability. Cells are seeded at a density of 104 cells per well into 96-well plates with 10 % fetal bovine serum and incubated for 24 h. Then, cells are treated with PF-3758309 at various concentrations (0, 0.01, 0.03, 0.1, 0.3, 1, 3, 10, and 30 μM) for 3 days. After the exposure period, the medium is changed and incubated with CCK-8 solution (10 % of the total volume)/well for 30 min. The medium is measured spectrophotometrically at 450 nm and the percentage of viable cells is estimated by comparison with the 0.3 % DMSO control cells.

Five- to six-week-old female athymic nude mice are used. Mice are caged in five groups and kept on a 12-h light/dark cycle and provided with sterilized food and water ad libitum. Animals are allowed to acclimate for at least 7 days before any handling. All CRC cells are harvested in exponential phase growth and resuspended in a 1:1 mixture of serum-free RPMI 1640 and Matrigel. Five to ten million cells per mouse are injected s.c. into the flank using a 23-gage needle. Mice are monitored daily for signs of toxicity and are weighed twice weekly. Tumor size is evaluated twice per week by caliper measurements using the following formula: tumor volume=length×width2×0.52. When tumors reached 150-300 mm3 mice are randomized into two groups with at least 10 tumors per group. Mice are then treated for 14 days with either vehicle control (0.5% methylcellulose), or PF-3758309 (25 mg/kg) twice daily by oral gavage.

[1]. Murray, Brion W., et al. Small-molecule p21-activated kinase inhibitor PF3758309 is a potent inhibitor of oncogenic signaling and tumor growth. Proceedings of the National Academy of Sciences of the United States of America (2010), 107(20), 9446-9451, S94

[2]. Zhao ZS, et al. Do PAKs make good drug targets? F1000 Biol Rep. 2010 Sep 23;2:70.

[3]. Ryu BJ, et al. PF-3758309, p21-activated kinase 4 inhibitor, suppresses migration and invasion of A549 human lung cancer cells via regulation of CREB, NF-κB, and β-catenin signalings. Mol Cell Biochem. 2014 Apr;389(1-2):69-77.

[4]. Pitts TM, et al. Association of the epithelial-to-mesenchymal transition phenotype with responsiveness to the p21-activated kinase inhibitor, PF-3758309, in colon cancer models. Front Pharmacol. 2013 Mar 28;4:35.

FRAX 486 | G 5555 | IPA-3 | FRAX 597 | FRAX1036 | 5-Aminosalicylic Acid | KPT-9274 | NVS-PAK1-1 | GNE 2861