B7-H1 agonists suppress the PI3K/AKT/mtor pathway by degrading p110γ and independently induce cell death.
Cancer Lett
; 584: 216615, 2024 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-38199586
ABSTRACT
The biological role of B7-H1 intrinsic signal is reportedly diverse and controversial, its signal pathway remains unclear. Although B7-H1 blocking antibodies were found to have agonist capacity, their binding features and agonist mechanisms need further investigation. Here, by constructing cell strains with full-length or truncated B7-H1, we found that B7-H1 functioned as a receptor to transmit cell death signal from PD-1 protein or anti-B7-H1s through its cytoplasmic domain. Specific binding to the IgV-like domain of B7-H1 was required for the downstream signal. Upon agonists interaction, B7-H1 regulated the degradation of phosphoinositide 3-kinases (PI3Ks) subunit p110γ, subsequently inhibited the PI3K/AKT/mTOR pathway, and significantly increased autophagy. Moreover, B7-H1 agonists also suppressed ubiquitylation in B7-H1+cells by reducing ubiquitin-activating enzyme (E1), eventually leading to cell death. Finally, we validated the receptor role of B7-H1 in multiple tumor cells and demonstrated that B7-H1 agonists could suppress tumor progression independent of T cells in vivo. Our findings revealed that B7-H1 agonists functions as a PI3K inhibitor and may offer new strategies for PI3K targeting therapy.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidilinositol 3-Quinases
/
Proteínas Proto-Oncogênicas c-akt
Idioma:
En
Revista:
Cancer Lett
Ano de publicação:
2024
Tipo de documento:
Article