Fig. 1

Upregulation of TRPM7, ORAI1 and STIM1 in clinical MM specimens and their inhibition by small molecule inhibitors in human MM cells. a-c Differential mRNA expression of TRPM7, ORAI1 and STIM1 in SMM and/or MM tissues in comparison to NPC in clinical datasets available on Oncomine™ bioinformatics database. *P < 0.05, **P < 0.01, ***P < 0.0001 versus NPC; two-tailed Student’s t-test. d, e Effect of SMIs of TRPM7, ORAI1, and STIM1 on intracellular Ca²⁺ levels. Human MM-derived RPMI8226 and NCI-H929 cells were treated with different concentrations of 2-APB (0–50 μM), AnCoA4 (0–40 μM) and SKF96365 (0–40 μM), and free intracellular Ca²⁺ levels were measured by a fluorescence plate reader using Fura-2 AM as a probe. Fura-2 signals were measured after a depletion of internal Ca²⁺ stores at 340/510 and 380/510 nm and reported as relative Fura-2 ratio to non-treated cells (NTX). f, g RPMI8226 and NCI-H929 cells were similarly treated with 2-APB (0–50 μM) (upper), AnCoA4 (0–40 μM) (middle), and SKF96365 (0–40 μM) (lower), and cell migration and invasion were evaluated by Transwell assays at 48 h. The penetrating cells were stained by Hoechst 33342 dye, quantified, and reported as percentage to NTX cells. Representative micrographs of migrating/invading cells stained with Hoechst 33342 are shown (see also Additional file 2: Fig. S4 for additional micrographs). Scale bar = 100 μm. Data are mean ± SD (n = 4). *P < 0.05, **P < 0.01, ***P < 0.001 versus NTX; two-tailed Student’s t-test