|Ph.D Student||Shoshan Stacy|
|Subject||Early Diagnosis of Cancer Using Serological Proteomics|
|Department||Department of Biology||Supervisor||Professor Arie Admon|
|Full Thesis text|
Potentially attractive source of cancer biomarkers are plasma autoantibodies reactive against specific tumor antigens. The main goal of this research was to identify the target antigens of autoantibody responses in breast cancer patients for future development of a screening blood test. Protein extracts of fresh frozen breast tumor and of healthy margin tissue were resolved on multiple large format two-dimensional gel electrophoresis (2-DE) in parallel. Some of gels were electro-blotted for western blot analysis using sera from breast cancer patients and healthy volunteers. This way, specific or elevated autoantibody responses against breast cancer proteins could be followed. Indeed, a differential pattern of autoantibody reactivity was noted when the 2-DE westerns of the breast cancer and healthy breast tissue extracts were probed with the autologous breast cancer patients’ or the healthy control sera. One area containing two rows of approximately five spots showed an autoantibody response exclusively in the 2-DE westerns of the breast cancer tissues that were probed with the patients’ sera. 7/9 breast cancer patients’ sera had detectable autoantibody responses to the proteins in these spots, whereas 3/4 healthy individual sera did not. Among the proteins identified in these spots, periostin was the most likely target of the visualized autoantibody response since it was the only protein among the different identified proteins in these spots that was present in the all the difference reactive spots and was absent from the identical location in the 2-DE gels of the healthy tissues. These observations suggest that anti-periostin autoantibodies are possibly potential serum markers for breast cancer, yet further validation is required.