title: Increased ROS production in non-polarized mammary epithelial cells induces monocyte infiltration in 3D culture.
abstract: Loss of epithelial cell polarity promotes cell invasion and cancer dissemination. Therefore, identification of factors that disrupt polarized acinar formation is crucial. Reactive oxygen species (ROS) drive cancer progression and promote inflammation. Here, we show that the non-polarized breast cancer cell line T4-2 generates significantly higher ROS levels than polarized S1 and T4R cells in three-dimensional (3D) culture, accompanied by induction of the nuclear factor κB (NF-κB) pathway and cytokine expression. Minimizing ROS in T4-2 cells with antioxidants reestablished basal polarity and inhibited cell proliferation. Introducing constitutively activated RAC1 disrupted cell polarity and increased ROS levels, indicating that RAC1 is a crucial regulator that links cell polarity and ROS generation. We also linked monocyte infiltration with disruption of polarized acinar structure using a 3D co-culture system. Gain- and loss-of-function experiments demonstrated that increased ROS in non-polarized cells is necessary and sufficient to enhance monocyte recruitment. ROS also induced cytokine expression and NF-κB activity. These results suggest that increased ROS production in mammary epithelial cell leads to disruption of cell polarity and promotes monocyte infiltration.
authors.affiliation: Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province 130021, China.|Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Linzhang
authors.initials: L
authors.lastname: Li
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Xiong
authors.affiliation: Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Daret K
authors.initials: DK
authors.lastname: St Clair
authors.affiliation: Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province 130021, China ren.xu2010@uky.edu xu_w@jlu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA ren.xu2010@uky.edu xu_w@jlu.edu.cn.|Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Ren
authors.identifier: 0000-0002-3591-9522
authors.initials: R
authors.lastname: Xu
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D002460:Cell Line; D016764:Cell Polarity; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology*; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D016207:Cytokines; D016328:NF-kappa B; C107953:RAC1 protein, human; D017382:Reactive Oxygen Species; D020830:rac1 GTP-Binding Protein
keywords: 3D cell culture; Breast cancer; Inflammation; Monocyte infiltration; Reactive oxygen species; Tissue polarity