title: Increased autophagic response in a population of metastatic breast cancer cells.
abstract: Breast cancer cells are heterogeneous in their ability to invade and fully metastasize, and thus also in their capacity to survive the numerous stresses encountered throughout the multiple steps of the metastatic cascade. Considering the role of autophagy as a survival response to stress, the present study hypothesized that distinct populations of breast cancer cells may possess an altered autophagic capacity that influences their metastatic potential. It was observed that a metastatic breast cancer cell line, MDA-MB-231, that was sensitive to autophagic induction additionally possessed the ability to proliferate following nutrient deprivation. Furthermore, a selected subpopulation of these cells that survived multiple exposures to starvation conditions demonstrated a heightened response to autophagic induction compared to their parent cells. Although this subpopulation maintained a more grape-like pattern in three-dimensional culture compared to the extended spikes of the parent population, autophagic induction in this subpopulation elicited an invasive phenotype with extended spikes. Taken together, these results suggest that autophagic induction may contribute to the ability of distinct breast cancer cell populations to survive and invade.
authors.affiliation: State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Y I
authors.initials: YI
authors.lastname: Li
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
authors.forename: Emily Falk
authors.initials: EF
authors.lastname: Libby
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
authors.forename: Monica J
authors.initials: MJ
authors.lastname: Lewis
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Shacka
authors.affiliation: Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Hurst
keywords: autophagy; breast cancer; heterogeneity; invasion; metastasis