Torin 2

Biological Activity

Torin 2 is a potent and selective inhibitor of cellular mTOR activity (EC50 = 0.3 nM). Torin 2 inhibits mTORC1, thus activates TFEB by promoting its nuclear translocation with EC50 of 1.666 mM. Torin 2 displays more than 800-fold selectivity for mTOR over PI3K (cellular EC50 values are 0.25 and 200 nM for mTOR and PI3K respectively) and greater than 100-fold binding selectivity relative to 440 other protein kinases. Torin 2 has significantly improved bioavailability (54%), metabolic stability, and plasma exposure compared to Torin 1. Torin 2 exhibits >95% pharmacodynamic response and half-time of 11.7 min in the mouse liver microsome stability study in vivo.

Protocol

Cell Experiment
Cell lines	MZ-CRC-1 and TT cells
Preparation method	Cell viability and motility assays For viability, MZ-CRC-1 and TT cells were seeded in quadruplicate in 96-well plates (10,000 cells per well) in culture media with 2.5% and 4% FBS, respectively. After 24 hours, cells were treated with the indicated compounds. At the indicated time point, cells were incubated for 3 hours with 10 μL of CellTiter96 AQueous One solution in 100 μL of culture media (Promega) and absorbance was measured at 490 nm. For migration assays, Transwell inserts with membranes of 8 μmol/L pore size (Corning-Costar) were used. Membranes were coated with 10 μg/mL collagen and kept at 4°C overnight. Cells were serum starved for 8 hours, detached by trypsin, and counted by hemocytometer. A total of 1 × 105 cells were plated in the upper chambers in serum-free medium, containing the vehicle or the indicated compounds (rapamycin: 100 nmol/L; everolimus/Rad001: 100 nmol/L, and Torin 2: 100 nmol/L). The lower chambers were filled with MZ-CRC-1 and TT culture media containing 2.5% and 4% FBS, respectively, supplemented with 20 ng/mL EGF (Sigma). After 24 hours, cells were fixed in methanol and stained with hematoxylin. Cells on the top surface of the membranes were wiped off with cotton swabs. Membranes were removed from the inserts, placed on microscope slides, and images acquired by Scanscope. Migrated cells were counted and the number of migrated cells per mm2 was calculated.
Concentrations	10, 50nM
Incubation time	5 days

Animal Experiment
Animal models	Six-week old male C57BL/6 mice model
Formulation	100% N-methyl-2-pyrrolidone and then diluted 1:4 with sterile 50% PEG400 prior to injection
Dosages	20 mg/kg for 6h
Administration	oral gavage

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

The ALK(F1174L) mutation potentiates the oncogenic activity of MYCN in neuroblastoma.
Berry T, et al. Cancer Cell. 2012 Jul 10;22(1):117-30. PMID: 22789543.

Discovery of 9-(6-aminopyridin-3-yl)-1-(3-(trifluoromethyl)phenyl)benzo[h][1,6]naphthyridin-2(1H)-one (Torin2) as a potent, selective, and orally available mammalian target of rapamycin (mTOR) inhibitor for treatment of cancer.
Liu Q, et al. J Med Chem. 2011 Mar 10;54(5):1473-80. PMID: 21322566.