Potent inhibitor of mTOR kinase in both mTORC1 and mTORC2
PP242, a novel potent and selective mTOR inhibitor, can inhibit the active site of mTOR kinase in both mTORC1 and mTORC2 with IC50 of 8 nM.
The mammalian target of rapamycin (mTOR), a serine-threonine kinase, is present in two protein complexes, mTORC1 and mTORC2, that have distinct subunit composition, substrates and mechanisms of activation.
Treatment of PP242 was shown to lead to the death of certain mouse and human leukemia cells [1]. In primary AML cells and CD34+ progenitor cells, PP242 can inhibit the activity of mTOR and their downstream targets, therefore inducing cell apoptosis [2].
The component has also been used to study the role of COX-2 in vivo. In models of acute leukemia harboring the Philadelphia chromosome (Ph) translocation, PP242 can delay the onset of leukemia and augment the effects of front-line tyrosine kinase inhibitors more effectively, thereby suppressing the expansion of leukemia [1]. In addition, PP242 was shown to suppresse leukemia progression in a murine leukemia model which was driven by mutated FLT3 with constitutive activation of mTOR [2].
参考文献:
1.Janes MR, Limon JJ, So L, Chen J, Lim RJ, Chavez MA, et al. Effective and selective targeting of leukemia cells using a TORC1/2 kinase inhibitor. Nat Med 2010,16:205-213.
2.Zeng Z, Shi YX, Tsao T, Qiu Y, Kornblau SM, Baggerly KA, et al. Targeting of mTORC1/2 by the mTOR kinase inhibitor PP242 induces apoptosis in AML cells under conditions mimicking the bone marrow microenvironment. Blood 2012,120:2679-2689.
| Kinase experiment [1]: | |
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In vitro mTOR (FRAP1) kinase assay |
Recombinant mTOR was incubated with PP242 at 2-fold dilutions over a concentration range of 50 ~ 0.001 μM in an assay containing 50 mM HEPES, pH 7.5, 1 mM EGTA, 10 mM MgCl2, 0.01% Tween, 10 μM ATP (2.5 μCi of γ-32P-ATP), and 3 μg/mL BSA. Rat recombinant PHAS-1/4EBP1 (2 mg/mL) was used as a substrate. Reactions were terminated by spotting onto nitrocellulose, which was washed with 1 M NaCl/1% phosphoric acid (approximately 6 times, 5 ~ 10 mins each). Sheets were dried and the transferred radioactivity was quantitated by phosphorimaging. IC50 value was calculated by fitting the data to a sigmoidal dose-response curve using the Prism software package. |
| Cell experiment [2]: | |
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Cell lines |
AML cells |
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Preparation method |
The solubility of this compound in DMSO is ≥61.6mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37 °C for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20 °C for several months. |
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Reaction Conditions |
0.1, 0.2, 0.6, 1.7 or 5.0 μM; 48 hrs |
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Applications |
In primary AML cells cultured alone or cocultured with stromal cells, PP242 dose-dependently induced apoptosis. In addition, PP242 induced apoptosis in CD34＋ AML progenitor cells cultured under the above-mentioned conditions. |
| Animal experiment [2]: | |
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Animal models |
Ba/F3-ITD/luc/GFP mouse model of leukemia |
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Dosage form |
60 mg/kg, p.o.; every other day |
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Applications |
At the dose of 60 mg/kg, PP242 reduced leukemia burden. In addition, The anti-leukemia effect of PP242 was greater than that of Rapamycin at the dose of 0.5 mg/kg (the tolerable dose that was previously shown to inhibit mTOR signaling). |
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Other notes |
Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal. |
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参考文献: [1]. Apsel B, Blair JA, Gonzalez B, Nazif TM, Feldman ME, Aizenstein B, Hoffman R, Williams RL, Shokat KM, Knight ZA. Targeted polypharmacology: discovery of dual inhibitors of tyrosine and phosphoinositide kinases. Nat Chem Biol. 2008 Nov;4(11):691-9. [2]. Zeng Z, Shi YX, Tsao T, Qiu Y, Kornblau SM, Baggerly KA, et al. Targeting of mTORC1/2 by the mTOR kinase inhibitor PP242 induces apoptosis in AML cells under conditions mimicking the bone marrow microenvironment. Blood 2012,120:2679-2689. | |
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