Compound 401

Biological Activity

Compound 401 is a potent inhibitor of DNA-PK (IC50=0.28 μM). Compound 401 is reported to be a poor inhibitor of PI3K, ATM, and ATR in vitro, but it is active against mTOR. Compound 401 shows activity against mTOR (IC50=5.3 μM) but not p110α/p85α PI3K (IC50>100 μM). Treatment of cells with Compound 401 blocks the phosphorylation of sites modified by mTOR-Raptor and mTOR-Rictor complexes (ribosomal protein S6 kinase 1 Thr389 and Akt Ser473, respectively). By contrast, there is no direct inhibition of Akt Thr308 phosphorylation, which is dependent on PI3K. Similar effects are also observed in cells that lack DNA-PK. Compound 401 inhibits immunoprecipitated epitope-tagged mTOR or endogenous mTOR in Raptor immunoprecipitates. In both cases, inhibition of 67% or 78% is obtained at 5 μM or 10 μM Compound 401, respectively. By contrast, dose response curves show that the p110α/p85α or p110β/p85α PI3K complexes are poorly inhibited by Compound 401 at these concentrations. The proliferation of TSC1-/- fibroblasts is inhibited in the presence of Compound 401, but TSC1+/+ cells are resistant.

Protocol

Cell Experiment
Cell lines	COS7 cells
Preparation method	Twenty-two hours later the cells were preincubated for 20 min with 0.1% dimethyl sulfoxide (Con) or the indicated concentrations of 401 (in μM).
Concentrations	25 μM
Incubation time	22 h

Animal Experiment
Animal models
Formulation
Dosages
Administration

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

Chemical Information

References

Inhibition of mammalian target of rapamycin signaling by 2-(morpholin-1-yl)pyrimido[2,1-alpha]isoquinolin-4-one.
Ballou LM, et al. J Biol Chem. 2007 Aug 17;282(33):24463-70. PMID: 17562705.