4EBP1 senses extracellular glucose deprivation and initiates cell death signaling in lung cancer.
Cell Death Dis
; 13(12): 1075, 2022 12 27.
Article
em En
| MEDLINE
| ID: mdl-36575176
ABSTRACT
Nutrient-limiting conditions are common during cancer development. The coordination of cellular glucose levels and cell survival is a fundamental question in cell biology and has not been completely understood. 4EBP1 is known as a translational repressor to regulate cell proliferation and survival by controlling translation initiation, however, whether 4EBP1 could participate in tumor survival by other mechanism except for translational repression function, especially under glucose starvation conditions remains unknown. Here, we found that protein levels of 4EBP1 was up-regulated in the central region of the tumor which always suffered nutrient deprivation compared with the peripheral region. We further discovered that 4EBP1 was dephosphorylated by PTPMT1 under glucose starvation conditions, which prevented 4EBP1 from being targeted for ubiquitin-mediated proteasomal degradation by HERC5. After that, 4EBP1 translocated to cytoplasm and interacted with STAT3 by competing with JAK and ERK, leading to the inactivation of STAT3 in the cytoplasm, resulting in apoptosis under glucose withdrawal conditions. Moreover, 4EBP1 knockdown increased the tumor volume and weight in xenograft models by inhibiting apoptosis in the central region of tumor. These findings highlight a novel mechanism for 4EBP1 as a new cellular glucose sensor in regulating cancer cell death under glucose deprivation conditions, which was different from its classical function as a translational repressor.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Ciclo Celular
/
Proteínas Adaptadoras de Transdução de Sinal
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Glucose
/
Neoplasias Pulmonares
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article