EXR-JFRAN1CRCKRAS-ST (Project)

Description:We have shown that exosomes released from mutant KRAS cell lines contain signaling-competent EGFR ligands and can transfer oncogenic KRAS to recipient wild-type KRAS-expressing cells, leading to enhanced growth in three-dimensional matrix and cell invasion in Boyden chamber assays. Previously, we reported preliminary results concerning the regulation of small RNA secretion in colorectal cancer cells using cell culture models. These RNA profiles were performed using exosomes and cells from three isogenic colon cancer lines: parental DLD-1 with both wild type and mutant KRAS alleles; DKS-8 (a single wild-type KRAS allele); and DKO-1 (a single mutant KRAS allele). We show that our exosomal preparations purified by traditional ultracentrifugation techniques contain lipoprotein complexes, as well as secreted vesicles consistent with exosomes. Part of our strategy going forward is to distinguish which RNAs are associated with vesicles or lipoproteins to understand how extracellular secretion is differentially regulated and whether it might be co-regulated by mutant KRAS. In addition to secreted RNAs that appear to be regulated by KRAS status and that are enriched in exosomes, we have analyzed unique features present in the short secreted RNAs. We have also performed long-RNAseq analysis on these same samples and will provide a preliminary analysis of longer RNA transcripts present in the media. We will discuss challenges and pitfalls as we move forward.

Abbreviation:JFRAN1CRCKRAS