Exosomes released by
tumor cells play critical roles in
tumor progression, immune cell suppression, and
cancer metastasis. The aim of the present study was to investigate whether the exosomes released by EL4 cells carry a functional
TNF-related apoptosis-inducing ligand (TRAIL) molecule. Exosomes were harvested from the supernatants of EL4 cell culture, and the shape, size, and identity of EL4-derived exosomes were evaluated by utilizing scanning electron microscopy, dynamic light scattering, and dot-blot method. The expression of
mRNA and
TRAIL protein in EL4 cells and EL4-exosomes were investigated using real-time PCR method and dot-blot analysis. Moreover, the effects of EL4-derived exosomes on cell death in a TRAIL-sensitive cell line (4T1) were studied by using flow cytometry (
annexin V/
propidium iodide (PI) staining) and fluorescent microscopy analyses (
acridine orange/
ethidium bromide staining). The results showed that EL4 cells continuously and without the need for stimulation, produce exosomes that carry
TRAIL protein. In addition, EL4-derived exosomes were capable to induce apoptosis as well as
necrosis in 4T1 cells. It was ultimately revealed that EL4 cells express
TRAIL protein and release exosomes containing functional TRAIL. Moreover, the released exosomes were able to induce apoptosis and
necrosis in a TRAIL-sensitive cell line. Further studies are needed to reveal the potential roles of
tumor-derived exosomes in the pathogenesis of
cancers.