MTX-211 Inhibits GSH Synthesis through Keap1/NRF2/GCLM Axis and Exerts Antitumor Effects in Bladder Cancer

Abstract

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.

ABCG2 Mediates Resistance to the Dual EGFR and PI3K Inhibitor MTX-211 in Cancer Cells

“…In the present study, our objective was to assess the influence of ABCG2 on the anti-proliferative efficacy of MTX-211. We observed that MTX-211 displayed inhibitory effects on cancer cell proliferation across various origins, with IC50 values falling within the range of approximately 1-8 µM, consistent with findings previously reported by Hu et al [3]. However, we noted the resistance to MTX-211 in cancer cells overexpressing ABCG2 alongside HEK293 cells ectopically expressing human ABCG2 (R482-HEK293), compared to parental HEK293 cells (Table 1).…”

“…The novel EGFR and PI3K dual inhibitor MTX-211 demonstrated promising preclinical activity [2,3]. More importantly, Maust et al highlight the potent growth-inhibitory properties of MTX-211 in BRAF-mutant and KRAS-mutant colorectal cancer models.…”

“…2024, 25, 5160 2 of 11 in the heightened cell apoptosis and substantial inhibition of tumor growth in mice with mutations in KRAS and p53 [2]. A recent investigation revealed that MTX-211 hinders the synthesis of reduced glutathione (GSH) and displays anti-proliferative effects in bladder cancer [3]. Nevertheless, the mechanisms driving the acquired resistance to MTX-211 in human cancer cells remain unexplored.…”

Nrf2 signaling pathway: current status and potential therapeutic targetable role in human cancers

“…In addition, MTX-211 is a potential antitumor agent that reduces GSH levels through the Keap1/Nrf2/GCLM signaling pathway ( 85 ), thereby effectively inhibits the proliferation of BCa cells. Therefore, regulating the metabolism of GSH through the Nrf2/GCLM signaling pathway may be an effective strategy for treating BCa or overcoming chemotherapy resistance ( 86 , 87 ). Like above-mentioned PC and PCa, in BCa, p62 functions the same model with Nrf2 ( 88 ).…”

Regulation of iron metabolism and ferroptosis in cancer stem cells

“…Similarly, the induction of ferroptosis increases drug sensitivity. In studies on various tumors such as head and neck cancer ( 28 ), pancreatic cancer ( 29 ), hepatocellular carcinoma ( 30 ), and bladder cancer ( 31 ), the induction of ferroptosis through mechanisms such as the regulation of GSH metabolism, lipid metabolism, and redox was found to be an effective strategy for overcoming drug resistance. Ferroptosis is an effective therapeutic approach for targeting CSCs.…”