[CAS NO. 862507-23-1]  Ralimetinib (LY2228820) dimesylate

LY2228820 inhibits p38α, as well as the level of phosphoMAPKAPK-2 (pMK2) in RAW 264.7 cells, with IC50 values of 7 nM and 34.3 nM, respectively. Furthermore, LY2228820 inhibits lipopolysaccharide (LPS)-induced TNFα formation in murine peritoneal macrophages, with IC50 of 5.2 nM. In multiple myeloma (MM) cells, including INA6, RPMI-8226, U266, and RPMI-Dox40, LY2228820 (200 nM–800 nM) significantly blocks p38MAPK signaling, as revealed by its inhibition on phosphorylation of HSP27, a downstream target of p38MAPK, without affecting the expression level of HSP27. LY2228820 (200 nM–400 nM) enhances bortezomib-induced cytotoxicity and apoptosis, but LY2228820 alone doesn't inhibit the growth of MM.1S cells. LY2228820 (200 nM–800 nM) also inhibits secretion of IL-6 and MIP-1α in long-term BM stromal cells (LT-BMSCs), BM mononuclear cells (BMMNCs), peripheral blood (PB) CD138, CD138 or PB CD14 cells. LY2228820 (400 nM–800 nM) also blocks osteoclastogenesis from CD14 cells.