Cell apoptosis assays were performed in a plasmacytoma cell line, FR4 cells and a myeloma cell line, RPMI8226 cells overexpressing wild-type FGFR3 (FGFR3(WT)) or two different mutants, FGFR3(K650E) or FGFR3(Y373C), and the induction of endoplasmic reticulum (ER) stress protein was compared between each type of cell.
PRO-001 did not inhibit constitutive activation of K650E, G384D, and Y373C FGFR3 in myeloma cell lines and failed to inhibit the growth of these cells.
Since cell lines may represent useful models for investigating the effects of deregulated FGFR3 mutants in MM, we analysed the expression, activation, signaling pathways and oncogenic potential of three mutants identified so far: the Y373C and K650E in the KMS-11 and OPM-2 cell lines respectively, and the novel G384D mutation here identified in the KMS-18 cell line.