Characterization of Exosomes From Ovarian Cancer and Ovarian Epithelial Cells
Posted: Tuesday, March 31, 2020
Exosomal proteins and lipids may prove to be a future biomarker for ovarian cancer, with use in the early diagnosis of the disease, as several differences exist in vitro between ovarian cancer cells and ovarian epithelial cells. Tianmin Xu, MD, PhD, of the Second Hospital of Jilin University, Changchun, China, and colleagues published this work in the Journal of Ovarian Research.
The researchers analyzed exosomes derived from ovarian cancer cells (SKOV-3) and ovarian surface epithelial cells (HOSEPiC). Exosomes were studied using transmission electron microscopy, flow cytometry, western blot, proteomics, and lipidomics. A total of 1,433 protein groups were identified from the exosomes of both cell lines. Of these groups, 659 were identified in both cell lines. Proteins such as collagen type V alpha 2 chain and lipoprotein lipase were present in significantly higher levels in the SKOV-3 exomes as compared with the HOSEPiC exomes. Other variations in exosomal proteins between the two cell lines were involved in molecular functions, including, but not limited to, transition metal ion transport, positive regulation of epithelial cell migration, transporter activity, and transmembrane transporter activity.
Lipidomic analysis identified 1,227 different lipid species present in the two cell lines. The SKOV-3 exosomes had higher levels of several lipid classes, including gangliosides, cholesterol esters, lysophosphatidylcholine, and zymosterol. SKOV-3 cells also showed lower expression of ceramides, phosphatidylserine, and sphingomyelin in their exosomes compared with the HOSEPiC cells. Of note, there was no significant difference in the triglyceride level between the two cell lines.
Disclosure: The authors reported no conflicts of interest.