biostudies-literatureUnknown7(1)da Silva ILQa-2 is believed to mediate a protective immune response against cancer; however, little is known about the role of Qa-2 in tumorigenesis. Here, we used 4T1 breast cancer cells to study the involvement of Qa-2 in tumor progression in a syngeneic host. Qa-2 expression was reduced during in vivo tumor growth and in cell lines derived from 4T1-induced tumors. Tumor-derived cells elicited an epithelial-mesenchymal transition associated with upregulation of Zeb1 and Twist1/2 and enhanced tumor initiating and invasive capacities. Furthermore, these cells showed increased stem characteristics, as demonstrated by upregulation of Hes1, Sox2 and Oct3/4, and enrichment of CD44^high/CD24^median/low cells. Remarkably, Qa-2 cell-surface expression was excluded from the CD44<sup>high<Scientific reports6276https://www.ebi.ac.uk/biostudies/studies/S-EPMC5524840biostudies-literatureReduced expression of the murine HLA-G homolog Qa-2 is associated with malignancy, epithelial-mesenchymal transition and stemness in breast cancer cells.PMC5524840Ferreira EToscano Simoes Rde Oliveira MCRenart JSoares Veloso ESalviano Teixeira CMartin-Villar EQuintanilla MMontero-Montero Lda Silva ILMartin-Perez JSainz BfalseReduced expression of the murine HLA-G homolog Qa-2 is associated with malignancy, epithelial-mesenchymal transition and stemness in breast cancer cells.Qa-2 is believed to mediate a protective immune response against cancer; however, little is known about the role of Qa-2 in tumorigenesis. Here, we used 4T1 breast cancer cells to study the involvement of Qa-2 in tumor progression in a syngeneic host. Qa-2 expression was reduced during in vivo tumor growth and in cell lines derived from 4T1-induced tumors. Tumor-derived cells elicited an epithelial-mesenchymal transition associated with upregulation of Zeb1 and Twist1/2 and enhanced tumor initiating and invasive capacities. Furthermore, these cells showed increased stem characteristics, as demonstrated by upregulation of Hes1, Sox2 and Oct3/4, and enrichment of CD44^high/CD24^median/low cells. Remarkably, Qa-2 cell-surface expression was excluded from the CD44<sup>high<2017-01-01T00:00:00Z2017 Jul2025-06-01T01:39:25.04Z2025-06-01T01:39:25.04ZS-EPMC55248402874023610.1038/s41598-017-06528-x