Discovery of exosomes as gastric cancer biomarkers from conditioned cell culture media.

• Main Author: Low, Su Jun.
• Other Authors: Sze Siu Kwan
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Medicine::Biosensors
• Online Access: http://hdl.handle.net/10356/45271
• Institution: Nanyang Technological University

Gastric cancer is the second leading cause of cancer-related deaths worldwide, largely due to frequent late diagnosis of the disease, since there are few efficient screening tests that can detect gastric cancer in its early stages. Exosomes are microvesicles, which contain various proteins, and have been associated with cancer progression. Several studies have analysed the proteomic profiles of exosomes from various cancer types and identified proteins that could serve as potential cancer diagnostic biomarkers. However, no study has been carried out to isolate exosome proteins as biomarker candidates for gastric cancer. In this study, we aim to profile the proteome of gastric cancer exosomes, and to identify suitable proteins that could act as gastric cancer biomarkers. We isolated exosomes by concentrating 100ml of conditioned cell culture media from 3 gastric cancer cell lines AGS, NCIN87 and IM95, and subjected them to ultracentrifugation. The results revealed several gastric cancer-secreted exosome proteins that were overexpressed as compared to control, hence reflecting their importance in cancer growth and rendering them potential diagnostic biomarkers for gastric cancer. Many proteins which were present in healthy cell-secreted exosomes were also found to be downregulated in gastric cancer-derived exosomes, thus providing an alternative source of diagnosis for gastric cancer.