title: KRAS-dependent sorting of miRNA to exosomes.
abstract: Mutant KRAS colorectal cancer (CRC) cells release protein-laden exosomes that can alter the tumor microenvironment. To test whether exosomal RNAs also contribute to changes in gene expression in recipient cells, and whether mutant KRAS might regulate the composition of secreted microRNAs (miRNAs), we compared small RNAs of cells and matched exosomes from isogenic CRC cell lines differing only in KRAS status. We show that exosomal profiles are distinct from cellular profiles, and mutant exosomes cluster separately from wild-type KRAS exosomes. miR-10b was selectively increased in wild-type exosomes, while miR-100 was increased in mutant exosomes. Neutral sphingomyelinase inhibition caused accumulation of miR-100 only in mutant cells, suggesting KRAS-dependent miRNA export. In Transwell co-culture experiments, mutant donor cells conferred miR-100-mediated target repression in wild-type-recipient cells. These findings suggest that extracellular miRNAs can function in target cells and uncover a potential new mode of action for mutant KRAS in CRC.
authors.affiliation: Department of Biological Sciences, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Diana J
authors.initials: DJ
authors.lastname: Cha
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Franklin
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Dou
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: James N
authors.initials: JN
authors.lastname: Higginbotham
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Michelle
authors.initials: M
authors.lastname: Demory Beckler
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Alissa M
authors.initials: AM
authors.lastname: Weaver
authors.affiliation: Department of Cardiology, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Kasey
authors.initials: K
authors.lastname: Vickers
authors.affiliation: HudsonAlpha Institute for Biotechnology, Huntsville, United States.
authors.forename: Nirpesh
authors.initials: N
authors.lastname: Prasad
authors.affiliation: HudsonAlpha Institute for Biotechnology, Huntsville, United States.
authors.forename: Shawn
authors.initials: S
authors.lastname: Levy
authors.affiliation: Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Coffey
authors.affiliation: Department of Biological Sciences, Vanderbilt University Medical Center, Nashville, United States.
authors.forename: James G
authors.initials: JG
authors.lastname: Patton
mesh_terms: D001692:Biological Transport; D018929:Cell Culture Techniques; D002460:Cell Line; D055354:Exosomes / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*
chemical_list: C117307:KRAS protein, human; D035683:MicroRNAs; D016283:Proto-Oncogene Proteins p21(ras)
keywords: KRAS; cancer; colorectal cancer; extracellular RNA; human; human biology; medicine; miRNA