Ruxolitinib phosphate (INCB18424 phosphate) is a JAK1/2 inhibitor with IC50 of 3.3 nM/2.8 nM. Its selectivity for JAK1/2 is more than 130 times that of JAK3.

JAK1:3.3 nM, JAK2:2.8 nM

METHODS: Mouse aortic vascular smooth muscle cells (VSMC), treated with ruxolitinib (0nM, 10nM, 50nM and 100nM) for 24 hours or 48 hours or pretreated with ruxolitinib (0nM, 10nM, 50nM and 100nM) or AG490 (50μM) 6 hours, and then treated with or without platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) for another 24 hours, and Western Blot blotting was performed to detect the levels of JAK2 and STAT3.
RESULTS The cell viability of PDGF-BB-treated VSMCs was reduced when treated with Ruxolitinib. Ruxolitinib partially inhibited the growth of VSMC cells by targeting the JAK2/STAT3 signaling pathway. [3]

METHODS: Mouse aortic vascular smooth muscle cells (VSMC), treated with ruxolitinib (0nM, 10nM, 50nM and 100nM) for 24 hours or 48 hours or pretreated with ruxolitinib (0nM, 10nM, 50nM and 100nM) or AG490 (50μM) 6 hours, and then treated with or without platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) for another 24 hours, and Western Blot blotting was performed to detect the levels of JAK2 and STAT3.
RESULTS The cell viability of PDGF-BB-treated VSMCs was reduced when treated with Ruxolitinib. Ruxolitinib partially inhibited the growth of VSMC cells by targeting the JAK2/STAT3 signaling pathway. [3]

Ruxolitinib phosphate is dissolved in 0.2% DMSO. Cells are seeded at 2000/well of white bottom 96-well plates, treated with compounds from DMSO stocks (0.2% final DMSO concentration), and incubated for 48 hours at 37°C with 5% CO2. Viability is measured by cellular ATP determination using the Cell-Titer Glo luciferase reagent or viable cell counting. Values are transformed to percent inhibition relative to vehicle control, and IC50?curves are fitted according to nonlinear regression analysis of the data using PRISM GraphPad.