Poster Presentation Australasian Extracellular Vesicles Conference 2018

Distinct shed microvesicle and exosome microRNA signatures reveal diagnostic markers for colorectal cancer (#96)

Maoshan Chen 1 , Rong Xu 2 , Alin Rai 2 , Wittaya Suwakulsiri 2 , Keiichi Izumikawa 3 , Hideaki Ishikawa 3 , David W Greening 2 , Nobuhiro Takahashi 3 , Richard J Simpson 2
  1. Australia Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, Australia
  2. La Trobe Institute for Molecular Science, Melbourne, VIC, Australia
  3. Department of Applied Biological Science, Tokyo University of Agriculture and Technology, Tokyo, Japan

Extracellular vesicle (EV) microRNAs are of major interest as potential diagnostic biomarkers in cancers. This study aims to identify miRNA profiles of shed microvesicles (sMVs) and exosomes (Exos) secreted from the isogenic colorectal cancer (CRC) cell lines SW480 and SW620 and evaluate their ability to predict CRC. Deep sequencing of miRNAs in cell lysates (CLs) and highly-purified sMVs and Exos was performed. We focused on miRNAs enriched in EVs and dysregulated miRNAs in metastatic cells (SW620) relative to primary cancer cells (SW480). We investigated the ability of EV miRNA signatures to predict CRC tumours using 594 tumour and 11 normal samples from TCGA. Compared to SW480-CLs we identified 61 and 73 were upregulated and downregulated in SW620-CLs, respectively. Selective distribution of cellular miRNAs into EVs results in distinct miRNA signatures for sMVs and Exos in each cell line. Cross cell line comparisons of EV miRNA profiles reveal a subset of miRNAs critical in CRC progression from primary carcinoma to metastasis. Many miRNAs non-detectable (<5 TPM) in CLs were significantly enriched in secreted EVs. Strikingly, miR-7641 which is non-detectable in SW480-CL but upregulated in SW620-CL is highly enriched in EVs secreted from both cell lines. Pearson correlation analysis demonstrated that EV miRNA profiles can be used to predict CRC tumours with ~96% accuracy. Our findings suggest that EV miRNA profiles from CRC cell lines may allow prediction of CRC tumours, and that miR-7641 may serve as an attractive candidate for the specific, non-invasive diagnosis and prognosis of CRC.