XBP1s is induced in MM patient BMSCs and TNF-α induces XBP1s up-regulation in healthy hBMSCs. (A) Western blot demonstrating XBP1s protein levels in primary BMSCs from MM patients and healthy donors. (B) Real-time PCR analysis demonstrating mRNA levels of Xbp1s (left), total Xbp1 (middle), and mRNA splicing of total Xbp1 (right) in the BMSCs of MM patients and healthy donors. The latter was determined as the ratio of Xbp1s to total Xbp1 mRNA levels (n = 3; mean ± SD; *P < .05; NS indicates not statistically significant). (C) Western blot demonstrating XBP1s protein levels in healthy donor BMSCstreated with MM1.S CM or cocultured with MM1.S cells (MM1.S). (D) Western blot demonstrating the effects of TNFα (10 ng/mL for 24 hours) on XBP1s protein levels in human BMS cell line KM101. (E) Real-time PCR results demonstrating the effects of TNFα (10 ng/mL for 24 hours) on mRNA levels of Xbp1s and total Xbp1 and mRNA splicing of total Xbp1 in KM101 cells (n = 3; mean ± SD; *P < .05). (F) Western blot demonstrating the effect of TNFα (10 ng/mL for 24 hours) on XBP1s protein levels in healthy donor BMSCs. (G) Real-time RT-PCR results demonstrating the effects of TNFα (10 ng/mL for 24 hours) on mRNA levels of Xbp1s and total Xbp1 and splicing of total Xbp1 mRNA in healthy donor BMSCs (n = 3; mean ± SD; *P < .05).