Secretome profiling of canine mammary tumor cells reveals AGR2-mediated regulation of protein secretion

ABSTRACT: Canine mammary tumors (CMTs) in intact female dogs serve as a valuable natural model for understanding human cancers. Our previous findings identified the overexpression of Anterior Gradient 2 (AGR2) in CMT tissues compared to normal mammary glands, highlighting its association with CMT progression. We observed that enhanced AGR2 expression actively promotes CMT cell chemotaxis by modulating the extracellular milieu. To decipher the AGR2-affected secretome associated with chemotaxis, we utilized gel-enhanced liquid chromatography-tandem mass spectrometry (GeLC-MS/MS) to scrutinize the conditioned media (CM) of AGR2-expressing CMT-U27 and CF41.Mg cells in comparison to the respective vector-expressing controls. In total, 798 proteins in CMT-U27 and 788 proteins in CF41.Mg were successfully identified and quantified. Among these proteins, 51 and 40 CM proteins were identified as AGR2-increased, while 28 and 50 CM proteins were designated as AGR2-decreased, respectively. Intriguingly, seven CM proteins exhibited increased abundance in both CMT-U27 and CF41.Mg cells, including AGR2, 14-3-3ε (gene name: YWHAE), and α-Actinin-4 (ACTN4). Ectopic AGR2 expression significantly increases the release of 14-3-3ε and ACTN4 in the CM. Conversely, knockdown or knockout of AGR2 expression remarkably reduces their release. AGR2 controls the release of 14-3-3ε and ACTN4, responsive to activation of ER stress and autophagy. Finally, depleting extracellular 14-3-3ε or ACTN4 reduces the AGR2-modulated CM chemotaxis. Our study uncovers the novel extracellular pro-oncogenic functions of 14-3-3ε and ACTN4 in the AGR2-modulated microenvironment.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Canis Familiaris (dog) (canis Lupus Familiaris)

TISSUE(S): Culture Fluid, Mammary Gland

DISEASE(S): Breast Cancer

SUBMITTER: Chih-Ching Wu  

LAB HEAD: Chih-Ching Wu

PROVIDER: PXD047008 | Pride | 2024-06-16

REPOSITORIES: Pride