Adarotene (Synonyms: ST1926)

Cell experiment:

Briefly, cells (1×107/mL) are loaded with 1 μM FURA-2 at 37°C in the dark for 30 minutes, washed twice, resuspended in phosphate-buffered saline (PBS) containing 1.26 mM CaCl2 at 106 cells/mL and then used for the experiments. Dual excitation, alternating at 340 nm and 380 nm, is provided by a spectrophotofluorometer equipped with 2 excitation monochromators, and emission is fixed at 480 nm. The temperature is set at 37°C±1°C. In some experiments, to eliminate extracellular calcium, cells preloaded with FURA-2 are resuspended in PBS without Ca2+, and 0.5 mM EGTA (ethylene glycol tetraacetic acid) is added to each sample prior to addition of the appropriate stimulus.

Animal experiment:

NB4 cells (3×106) are intraperitoneally inoculated in SCID mice (8 mice/group). ST1926 is dissolved in cremophor/ethanol 1:1 solution, and diluted 1:10 in PBS at the concentration of 50 mg/kg; the doses of 30 mg/kg and 40 mg/kg are then prepared by appropriate dilutions in the same vehicle. ATRA is dissolved in the dark in Cremophor EL and kept magnetically stirred; the solution is then diluted 1:10 in PBS at the final concentration of 40 mg/kg. Both compounds are administered intraperitoneally and orally twice per day for 3 weeks starting from the day after cell inoculation, in a volume of 10 mL/kg. During treatments body weight and lethality are registered.

References:

[1]. Cincinelli R, et al. A novel atypical retinoid endowed with proapoptotic and antitumor activity. J Med Chem. 2003 Mar 13;46(6):909-12.
[2]. Garattini E, et al. ST1926, a novel and orally active retinoid-related molecule inducing apoptosis in myeloid leukemia cells: modulation of intracellular calcium homeostasis. Blood. 2004 Jan 1;103(1):194-207.