Glycoprotein non-metastatic melanoma protein B functions with growth factor signaling to induce tumorigenesis through its serine phosphorylation.
Cancer Sci
; 112(10): 4187-4197, 2021 Oct.
Article
em En
| MEDLINE
| ID: mdl-34327762
ABSTRACT
Breast cancer is the most common cancer among women. Glycoprotein non-metastatic melanoma protein B (GPNMB), a type I transmembrane protein that is highly expressed in many cancers, including breast cancer, has been shown to be a prognostic factor. We previously reported that GPNMB overexpression confers tumorigenic potential, as evidenced by invasive tumor growth in vivo, sphere formation, and cellular migration and invasion to non-tumorigenic mammary epithelial cells. In this study, we focused on the serine (S) residue in the intracellular domain of GPNMB (S530 in human isoform b and S546 in mouse), which is predicted to be a phosphorylation site. To investigate the roles of this serine residue, we made an antibody specific for S530-phosphorylated human GPNMB and a point mutant in which S530 is replaced by an alanine (A) residue, GPNMB(SA). Established GPNMB(SA) overexpressing cells showed a significant reduction in sphere formation in vitro and tumor growth in vivo as a result of decreased stemness-related gene expression compared to that in GPNMB(WT)-expressing cells. In addition, GPNMB(SA) impaired GPNMB-mediated cellular migration. Furthermore, we found that tyrosine kinase receptor signaling triggered by epidermal growth factor or fibroblast growth factor 2 induces the serine phosphorylation of GPNMB through activation of downstream oncoproteins RAS and RAF.
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Base de dados:
MEDLINE
Assunto principal:
Serina
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Glicoproteínas de Membrana
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article