Fig. 4

Increased G6PD expression enhances MM cell resistance to Dexa, but not BTZ. a The mRNA expression levels of G6PD were markedly increased in relapsed MM patients compared with baseline. Differences were compared using an unpaired t-test. b G6PD expression was associated with patient survival in the APEX clinical trial based on a log-rank test. c G6PD expression was higher in patients who did not respond to Dexa treatment compared with patients who did respond to Dexa treatment. d No significant difference in G6PD expression was observed between patients who did and did not respond to BTZ. e, f Overexpression of G6PD enhanced Dexa resistance in ARP1 (e) and H929 (f) G6PD-OE cells compared with the respective WT cells. g, h Flow cytometry analyses confirmed that overexpression of G6PD attenuated Dexa-induced apoptosis in G6PD-OE cells relative to WT cells. i, j Flow cytometry analyses indicated that MM1.R cells resistant to Dexa exhibited an increased degree of apoptosis upon RRX-001 treatment. ***p < 0.001 was considered statistically significant