Cell lines

Murine embryonic stem (ES) cells

Preparation method

The solubility of this compound in DMSO is >17.45mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

10 μM and 20 μM; 24 or 48 h

Applications

In murine ES cells, pifithrin-α significantly reduced the number and colony size of the ES cells in a dose dependent way. In ES cells seeded at low density in the presence of LIF, pifithrin-α significantly reduced the number of formed secondary ES cell colonies.

Animal models

Balb/c and C57BL6 mice treated with whole-body gamma irradiation

Dosage form

2.2 mg/kg; i.p. injection

Application

In Balb/c and C57BL6 mice treated with whole-body gamma irradiation, pifithrin-α completely rescued mice of both strains from 60% killing doses of gamma irradiation (8 Gy for C57BL and 6 Gy for Balb/c). pifithrin-α did not protect p53-null mice from lethal irradiation, suggesting that pifithrin-α acted through a p53-dependent way.

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.

Pifithrin-α is a synthetic, water-soluble and stable inhibitor of p53 [1].

Pifithrin-α is firstly found to block the activation of p53-responsive lacZ in ConA cells and reduce activation of endogenous cellular p53-responsive genes. In MEF cells transformed with E1a+ras, 10μM Pifithrin-α can inhibit the apoptosis of the cells and this anti-apoptotic activity is p53-dependent. Pifithrin-α also inhibits the growth arrest of human diploid fibroblasts induced by DNA damage but has no effect on p53-deficient fibroblasts. In addition, Pifithrin-α induces G2-arrest of cells after gamma irradiation [1].

Moerover, Pifithrin-α can also induce cell cycle arrest and growth arrest of embryonic stem cells. Treatment of Pifithrin-α significantly downregulates the protein lever of Nanog (a pluripotency marker).It is proved that the inhibition of p53 activity caused by Pifithrin-α has no effect on ES cell viability [2].

References:
[1] Komarov PG, Komarova EA, Kondratov RV, Christov-Tselkov K, Coon JS, Chernov MV, Gudkov AV. A chemical inhibitor of p53 that protects mice from the side effects of cancer therapy. Science. 1999 Sep 10;285(5434):1733-7.
[2] Abdelalim EM, Tooyama I. The p53 inhibitor, pifithrin-α, suppresses self-renewal of embryonic stem cells. Biochem Biophys Res Commun. 2012 Apr 13;420(3):605-10.