H7 inhibits Jak2- and erythropoietin-induced activation of the Stat5-dependent reporter.

293T cells were transfected with 1 μg Stat5-responsive SPI luciferase construct and 0.2 μg β-galactosidase, together with 0.25 μg erythropoietin (Epo)R expression vector, 0.5 μg Stat5 expression vector, and 1 μg Jak2 expression vector, as indicated. Where indicated, O/N-starved 293T cells were treated with IL-4 (10 ng/mL) or Epo (4 IU/mL) for 6 hours. H7 (50 μmol/L) was added either 30 minutes before cytokine stimulation or 20 hours before harvesting in Jak2-transfected cells. β-Galactosidase and luciferase values were measured, and luciferase values were normalized against β-galactosidase values. The experiment was repeated twice and yielded identical results.