Mutant KRAS colorectal cancer (CRC) cells release protein-laden exosomes that can alter the tumor microenvironment. To test whether exosomal RNA might also contribute to changes in gene expression in recipient cells, and to test whether mutant KRAS might regulate the composition of secreted 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 KRAS exosomes cluster separately from wild type KRAS exosomes. miR-10b was selectively increased in wild type KRAS exosomes while miR-100 was increased in mutant KRAS exosomes. Neutral sphingomyelinase inhibition caused accumulation of miR-100 only in mutant KRAS cells, suggesting KRAS-dependent miRNA export. In Transwell co-culture experiments, mutant KRAS donor cells conferred miR-100 -mediated target repression in wild type KRAS recipient cells. These findings suggest extracellular miRNAs can function in target cells and uncover a potential new mode of action for mutant KRAS in CRC.
|Advisor:||Graham, Todd R.|
|Commitee:||Coffey, Robert, Graham, Todd, Patton, james G., Rokas, Antonis, Vickers, Kasey|
|School Location:||United States -- Tennessee|
|Source:||DAI-B 80/06(E), Dissertation Abstracts International|
|Subjects:||Biology, Molecular biology, Cellular biology|
|Keywords:||Colon cancer, ExRNA, Exosomes, KRAS, miRNA|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be