Assessing the role of the integrin αVβ6 in triple negative breast cancer phenotypes

Integrin are a family of heterodimeric proteins that mediates cell migration, polarity and signaling. The integrin αVβ6, is typically expressed during physiological processes such as embryogenesis, and fibrosis. Aberrant expression is associated with different types of cancer and metastasis with higher expression correlating to poor prognosis in patients. In order to understand how αVβ6 can mediate cancer specific phenotypes, research was conducted on triple negative breast cancer cell lines (TNBC), a particularly aggressive cancer subtype. TNBC cell lines MDA-MB-468 (αVβ6+) and MDA-MB-231 (αVβ6-) were used as models to study αVβ6 mediated phenotypes. Inducing the over-expression of αVβ6 in MDA-MB-231 results in a decrease in proliferation, while silencing αVβ6 enhances it, indicating that αVβ6 is required and sufficient for proliferation in TNBC. This negative regulation was also seen in the expression of the EMT marker vimentin while no change in E-cadherin was observed. Vimentin corresponds to a more motile phenotype. Thus, the data indicates that αVβ6 results in a highly epithelial phenotype marked by a decrease in proliferation and migration.