Globally, bladder cancer (BLCA) is still the leading cause of death in patients with tumors. The function and underlying mechanism of MTX-211, an EFGR and PI3K kinase inhibitor, have not been elucidated. This study examined the function of MTX-211 in BLCA cells using in vitro and in vivo assays. RNA sequencing, quantitative real-time polymerase chain reaction, Western blotting, co-immunoprecipitation, and immunofluorescence were performed to elucidate the underlying mechanism. Our observations revealed that MTX-211 has a time- and concentration-dependent inhibitory effect on bladder cancer cell proliferation. Flow cytometry analysis showed that cell apoptosis and G0/G1 cell cycle arrest were significantly induced by MTX-211. MTX-211 inhibited intracellular glutathione (GSH) metabolism, leading to a decrease in GSH levels and an increase in reactive oxygen species. GSH supplementation partly reversed the inhibitory effects of MTX-211. Further experiments verified that MTX-211 promoted NFR2 protein ubiquitinated degradation via facilitating the binding of Keap1 and NRF2, subsequently resulting in the downregulated expression of GCLM, which plays a vital role in GSH synthesis. This study provided evidence that MTX-211 effectively inhibited BLCA cell proliferation via depleting GSH levels through Keap1/NRF2/GCLM signaling pathway. Thus, MTX-211 could be a promising therapeutic agent for cancer.
Keywords: GSH metabolism; Keap1/NRF2/GCLM; MTX-211; bladder cancer; proliferation.