title: MicroRNAs are exported from malignant cells in customized particles.
abstract: MicroRNAs (miRNAs) are released from cells in association with proteins or microvesicles. We previously reported that malignant transformation changes the assortment of released miRNAs by affecting whether a particular miRNA species is released or retained by the cell. How this selectivity occurs is unclear. Here we report that selectively exported miRNAs, whose release is increased in malignant cells, are packaged in structures that are different from those that carry neutrally released miRNAs (n-miRNAs), whose release is not affected by malignancy. By separating breast cancer cell microvesicles, we find that selectively released miRNAs associate with exosomes and nucleosomes. However, n-miRNAs of breast cancer cells associate with unconventional exosomes, which are larger than conventional exosomes and enriched in CD44, a protein relevant to breast cancer metastasis. Based on their large size, we call these vesicles L-exosomes. Contrary to the distribution of miRNAs among different microvesicles of breast cancer cells, normal cells release all measured miRNAs in a single type of vesicle. Our results suggest that malignant transformation alters the pathways through which specific miRNAs are exported from cells. These changes in the particles and their miRNA cargo could be used to detect the presence of malignant cells in the body.
authors: Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.
authors: Jaime
authors: J
authors: Palma
authors: Sree C
authors: SC
authors: Yaddanapudi
authors: Lucy
authors: L
authors: Pigati
authors: Mallory A
authors: MA
authors: Havens
authors: Sarah
authors: S
authors: Jeong
authors: Geoffrey A
authors: GA
authors: Weiner
authors: Kristina Mary Ellen
authors: KM
authors: Weimer
authors: Brittany
authors: B
authors: Stern
authors: Michelle L
authors: ML
authors: Hastings
authors: Dominik M
authors: DM
authors: Duelli
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D055354:Exosomes / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis; D035683:MicroRNAs / Q000032:analysis / Q000145:classification / Q000378:metabolism*; D009707:Nucleosomes / Q000737:chemistry; D034443:RNA Transport; D022161:Transport Vesicles / Q000737:chemistry / Q000145:classification / Q000378:metabolism
chemical_list: D018960:Hyaluronan Receptors; D035683:MicroRNAs; D009707:Nucleosomes