Curbing Breast Cancer by Altering V-ATPase Action on F-Actin, Heterochromatin, ETV7 and mTORC2 Signaling.
Cell Physiol Biochem
; 58(3): 250-272, 2024 Jun 12.
Article
en En
| MEDLINE
| ID: mdl-38865588
ABSTRACT
BACKGROUND/AIMS:
Motivated by the vacuolar proton pump's importance in cancer, we investigate the effects of proton pump inhibition on breast cancer cell migration and proliferation, F-actin polymerization, lamin A/C, heterochromatin, and ETV7 expressions, nuclear size and shape, and AKT/mTOR signaling.METHODS:
Lowly metastatic MCF7 and highly metastatic MDA-MB-231 breast cancer cells were treated with 120 nM of proton pump inhibitor Bafilomycin A1 for 24 hours. Cell migration was studied with wound- scratch assays, ATP levels with a chemiluminescent assay; cell proliferation was quantified by a cell area expansion assay. Nuclear size and shape were determined using DAPI nuclear stain and fluorescence microscopy. The levels of F-actin, lamin A/C, heterochromatin, and ETV7 were quantified using both immunocytochemistry and western blots; p-mTORC1, p-mTORC2, mTOR, p-AKT, and AKT were measured by western blots.RESULTS:
We reveal that proton pump inhibition reduces F-actin polymerization, cell migration, proliferation, and increases heterochromatin in both lowly and highly metastatic cells. Surprisingly, Bafilomycin decreases lamin A/C in both cell lines. Inhibition has different effects on ETV7 expression in lowly and highly metastatic cells, as well as nuclear area, perimeter, and circularity. Bafilomycin also significantly decreases p-mTORC1, p-MTORC2, and MTOR expression in both cell lines, whereas it significantly decreases p-AKT in lowly metastatic cells and surprisingly significantly increases p-AKT in highly metastatic cells. Our proton pump inhibition protocol reduces V-ATPase levels (~25%) within three hours. V-ATPase levels vary in time for both control and inhibited cells, and inhibition reduces cellular ATP.CONCLUSION:
Proton pumps promote F-actin polymerization and decrease heterochromatin, facilitating invasion. These pumps also upregulate both mTORC1 and mTORC2, thus highlighting the relevance of vacuolar proton pumps as metastatic cancer targets.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Neoplasias de la Mama
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Heterocromatina
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Transducción de Señal
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Movimiento Celular
/
Actinas
/
Macrólidos
/
ATPasas de Translocación de Protón Vacuolares
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Proliferación Celular
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Proteínas Proto-Oncogénicas c-akt
/
Serina-Treonina Quinasas TOR
Límite:
Female
/
Humans
Idioma:
En
Revista:
Cell Physiol Biochem
Asunto de la revista:
BIOQUIMICA
/
FARMACOLOGIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos