Tofacitinib (CP-690550) Citrate

2 years -80 in solvent

Oral gavage

FDCP-EpoR JAK2WT and JAK2V617F cell lines

0-4 uM

0.5% methylcellulose in distilled water

Tofacitinib citrate inhibits IL-2-mediated human T cell blast proliferation and IL-15-induced CD69 expression with IC50 of 11 nM and 48 nM, respectively. Tofacitinib citrate prevents mixed lymphocyte reaction with IC50 of 87 nM. Tofacitinib citrate treatment of murine factor-dependent cell Patersen–erythropoietin receptor (FDCP-EpoR) cells harboring human wild-type or V617F JAK2 leads to prevention of cell proliferation with IC50 of 2.1 uM and 0.25 uM, respectively. Tofacitinib citrate inhibits interleukin-6-induced phosphorylation of STAT1 and STAT3 with IC50 of 23 nM and 77 nM, respectively. Moreover, Tofacitinib citrate generates a significant pro-apoptotic effect on murine FDCP-EpoR cells carrying JAK2VV617F, whereas a lesser effect was observed for cells carrying wild-type JAK2. This activity is coupled with the inhibition of phosphorylation of the key JAK2V617F-dependent downstream signaling effectors signal transducer and activator of transcription (STAT)3, STAT5, and v-akt murine thymoma viral oncone homolog (AKT). [2] Additionally, Tofacitinib citrate prevents IL-15-induced CD69 expression in human and cynomolgus monkey NK and CD8+ T cells in vitro. [3]

72 hours

Determination of growth inhibition by Tofacitinib citrate is performed using identical culture conditions for both FDCP-EpoR JAK2WT and JAK2V617F cell lines. Briefly, 1, 105 cells/mL are cultured in 96-well flat-bottom plates at 37 C in a humidified 5% CO2 atmosphere using RPMI 1640 supplemented with 1.25% FCS, and 5% WEHI supernatant. Decreased FCS concentration is necessary to prevent binding between Tofacitinib citrate and serum proteins. Growth inhibition assays are terminated by addition of 20 uL CellTiter96 One Solution Reagent. Flat-bottom plates are incubated for an additional 3 hours for MTT assay. Absorbance is determined at 595 nm on a BioTek Synergy-HT microplate reader. Results are the average +/- standard deviation of three independent determinations.

Tofacitinib citrate (CP-690550, Tasocitinib) is a novel inhibitor of JAK with IC50 of 1 nM, 20 nM and 112 nM against JAK3, JAK2, and JAK1, respectively. Tofacitinib citrate has anti-infection activity.