title: RANK induces epithelial-mesenchymal transition and stemness in human mammary epithelial cells and promotes tumorigenesis and metastasis.
abstract: Paracrine signaling through receptor activator of NF-κB (RANK) pathway mediates the expansion of mammary epithelia that occurs during pregnancy, and activation of RANK pathway promotes mammary tumorigenesis in mice. In this study we extend these previous data to human cells and show that the RANK pathway promotes the development of mammary stem cells and breast cancer. Overexpression of RANK (FL-RANK) in a panel of tumoral and normal human mammary cells induces the expression of breast cancer stem and basal/stem cell markers. High levels of RANK in untransformed MCF10A cells induce changes associated with both stemness and transformation, including mammary gland reconstitution, epithelial-mesenchymal transition (EMT), increased migration, and anchorage-independent growth. In addition, spheroids of RANK overexpressing MCF10A cells display disrupted acinar formation, impair growth arrest and polarization, and luminal filling. RANK overexpression in tumor cells with nonfunctional BRCA1 enhances invasiveness in acinar cultures and increases tumorigenesis and metastasis in immunodeficient mice. High levels of RANK were found in human primary breast adenocarcinomas that lack expression of the hormone receptors, estrogen and progesterone, and in tumors with high pathologic grade and proliferation index; high RANK/RANKL expression was significantly associated with metastatic tumors. Together, our findings show that RANK promotes tumor initiation, progression, and metastasis in human mammary epithelial cells by increasing the population of CD44(+)CD24(-) cells, inducing stemness and EMT. These results suggest that RANK expression in primary breast cancer associates with poor prognosis.
authors.affiliation: Cancer Epigenetics and Biology Program, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Palafox
authors.forename: Irene
authors.initials: I
authors.lastname: Ferrer
authors.forename: Pasquale
authors.initials: P
authors.lastname: Pellegrini
authors.forename: Sergi
authors.initials: S
authors.lastname: Vila
authors.forename: Sara
authors.initials: S
authors.lastname: Hernandez-Ortega
authors.forename: Ander
authors.initials: A
authors.lastname: Urruticoechea
authors.forename: Fina
authors.initials: F
authors.lastname: Climent
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Soler
authors.forename: Purificación
authors.initials: P
authors.lastname: Muñoz
authors.forename: Francesc
authors.initials: F
authors.lastname: Viñals
authors.forename: Mark
authors.initials: M
authors.lastname: Tometsko
authors.forename: Dan
authors.initials: D
authors.lastname: Branstetter
authors.forename: William C
authors.initials: WC
authors.lastname: Dougall
authors.forename: Eva
authors.initials: E
authors.lastname: González-Suárez
mesh_terms: D000818:Animals; D019313:BRCA1 Protein / Q000502:physiology; D001943:Breast Neoplasms / Q000209:etiology* / Q000473:pathology; D051927:CD24 Antigen / Q000032:analysis; D045744:Cell Line, Tumor; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis; D051379:Mice; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D053245:RANK Ligand / Q000032:analysis; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000032:analysis / Q000502:physiology*
chemical_list: D019313:BRCA1 Protein; D051927:CD24 Antigen; D018960:Hyaluronan Receptors; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C505686:TNFRSF11A protein, human