Fig. 5.

DKO-1 exosomes transfer mutant KRAS to DKs-8 cells and enhance three-dimensional growth of non-transformed cells. A, B, mutant (G13D) KRAS is present in DKs-8 cells after incubation with DKO-1 exosomes, whereas WT HRAS and NRAS levels are unchanged. Concentrations of KRAS, HRAS, and NRAS peptides were normalized to protein input and reported as fmol/μg protein. Data are plotted as the mean ± S.D. Experiments were performed in triplicate. The level of G13D mutant KRAS peptide in DKs-8 cells treated with DKO-1 exosomes represents a p value of 0.00009 compared to mock treated DKs-8 control cells. C, DKs-8 and DKO-1 cells were plated in collagen matrix as described in the text. The cells were cultured in serum-free medium or serum-free medium supplemented with the indicated exosomes for 14 days, and the respective media were changed twice weekly. Three independent experiments were performed in triplicate. The colony number was quantified and plotted. Data represent the mean ± the S.E. (* indicates p < 0.05). D, RIE-1 cells were plated in soft agar with mock treatment, DKO-1 exosomes, or DKs-8 exosomes and cultured for 7 days. Colonies were counted and plotted as the mean ± the S.E. (* indicates p < 0.01). Three independent experiments were performed in triplicate.