title: The role of lipolysis stimulated lipoprotein receptor in breast cancer and directing breast cancer cell behavior.
abstract: The claudin-low molecular subtype of breast cancer is of particular interest for clinically the majority of these tumors are poor prognosis, triple negative, invasive ductal carcinomas. Claudin-low tumors are characterized by cancer stem cell-like features and low expression of cell junction and adhesion proteins. Herein, we sought to define the role of lipolysis stimulated lipoprotein receptor (LSR) in breast cancer and cancer cell behavior as LSR was recently correlated with tumor-initiating features. We show that LSR was expressed in epithelium, endothelium, and stromal cells within the healthy breast tissue, as well as in tumor epithelium. In primary breast tumor bioposies, LSR expression was significantly correlated with invasive ductal carcinomas compared to invasive lobular carcinomas, as well as ERα positive tumors and breast cancer cell lines. LSR levels were significantly reduced in claudin-low breast cancer cell lines and functional studies illustrated that re-introduction of LSR into a claudin-low cell line suppressed the EMT phenotype and reduced individual cell migration. However, our data suggest that LSR may promote collective cell migration. Re-introduction of LSR in claudin-low breast cancer cell lines reestablished tight junction protein expression and correlated with transepithelial electrical resistance, thereby reverting claudin-low lines to other intrinsic molecular subtypes. Moreover, overexpression of LSR altered gene expression of pathways involved in transformation and tumorigenesis as well as enhanced proliferation and survival in anchorage independent conditions, highlighting that reestablishment of LSR signaling promotes aggressive/tumor initiating cell behaviors. Collectively, these data highlight a direct role for LSR in driving aggressive breast cancer behavior.
authors.affiliation: Department of Biology, North Carolina Central University, Durham, North Carolina, United States of America.
authors.forename: Denise K
authors.initials: DK
authors.lastname: Reaves
authors.affiliation: Department of Biology, North Carolina Central University, Durham, North Carolina, United States of America.
authors.forename: Katerina D
authors.initials: KD
authors.lastname: Fagan-Solis
authors.affiliation: Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, United States of America.
authors.forename: Karen
authors.initials: K
authors.lastname: Dunphy
authors.affiliation: Department of Biology, North Carolina Central University, Durham, North Carolina, United States of America.
authors.forename: Shannon D
authors.initials: SD
authors.lastname: Oliver
authors.affiliation: Department of Cell Physiology and Cell Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: David W
authors.initials: DW
authors.lastname: Scott
authors.affiliation: Department of Biology, North Carolina Central University, Durham, North Carolina, United States of America.
authors.forename: Jodie M
authors.initials: JM
authors.lastname: Fleming
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D057167:Claudins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008066:Lipolysis; D018110:Receptors, Lipoprotein / Q000235:genetics / Q000378:metabolism*; D012307:Risk Factors; D019108:Tight Junctions / Q000235:genetics / Q000378:metabolism
chemical_list: D057167:Claudins; D018110:Receptors, Lipoprotein