The O-linked-β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is a critical post-translational modification that couples the external stimuli to intracellular signal transduction networks. However, the critical protein targets of O-GlcNAcylation in oxidative stress-induced apoptosis remain to be elucidated. Here, we show that treatment with H 2 O 2 inhibited O-GlcNAcylation, impaired cell viability, increased the cleaved caspase 3 and accelerated apoptosis of neuroblastoma N2a cells. The O-GlcNAc transferase (OGT) inhibitor OSMI-1 or the O-GlcNAcase (OGA) inhibitor Thiamet-G enhanced or inhibited H 2 O 2 -induced apoptosis, respectively. The total and phosphorylated protein levels, as well as the promoter activities of signal transducer and activator of transcription factor 3 (STAT3) and Forkhead box protein O 1 (FOXO1) were suppressed by OSMI-1. In contrast, overexpressing OGT or treating with Thiamet-G increased the total protein levels of STAT3 and FOXO1. Overexpression of STAT3 or FOXO1 abolished OSMI-1-induced apoptosis. Whereas the anti-apoptotic effect of OGT and Thiamet-G in H 2 O 2 -treated cells was abolished by either downregulating the expression or activity of endogenous STAT3 or FOXO1. These results suggest that STAT3 or FOXO1 are the potential targets of O-GlcNAcylation involved in the H 2 O 2 -induced apoptosis of N2a cells.
The limited treatment options for colorectal cancer (CRC) and its adverse effects of chemotherapy underscore the urgent need for innovative therapeutic strategies. Focusing on early cellular glycosylation, particularly through the targeting of O-GlcNAcylation with small-molecule inhibitors, emerges as a promising direction. In this study, we developed artificial cell-like nanovesicles with a bilayer membrane structure to encapsulate OSMI-1, a specific inhibitor of O-GlcNAc transferase, aimed at inhibiting CRC progression. To enhance the effectiveness and specificity of the treatment, these self-targeted nanovesicles (T–Se–Lip–OSMI) were reinforced using internal diselenide bridges enabling redox-responsive release within the tumor microenvironment. In vitro assays revealed that T–Se–Lip–OSMI substantially diminished CRC cell proliferation, migration, and invasion. This was further validated using patient-derived organoid models, which highlighted the superior therapeutic efficacy of T–Se–Lip–OSMI over nanovesicles without the diselenide bridge. Subsequent in vivo studies confirmed its targeted delivery and pronounced suppression of tumor growth. Further mechanistic analysis illustrated that the therapeutic effect was mediated through the inhibition of O-GlcNAcylation of the Yes-associated protein (YAP), ultimately preventing the nuclear translocation of YAP and the activation of oncogenic downstream targets. This study leverages the unique properties of the diselenide bridge to enhance stability and functionality of the nanovesicles, offering a novel avenue for targeted CRC treatment.
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