Professor, Beijing Normal University, China.
Title: Urinary protein changes in walker 256 tumor-bearing rats
Youhe Gao received his M.D. from Peking Union Medical College, his Ph.D. from University of Connecticut and postdoctoral training from Beth Israel Deaconess Medical Center Harvard Medical School. He is the professor of Department of Physiology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences/ Peking Union Medical College. His research interests include urine proteomics, biomarker discovery, protein interaction and related bioinformatics.
Without homeostatic control, urine reflects early changes in the body. In this study, the Walker 256 tumor rat model was established by subcutaneous injection. To identify urinary proteome changes during the entire development of cancer, urine samples of walker 256 tumor-bearing rats were collected at five time points corresponding to before cancer cell implant, before tumor mass palpable, tumor mass appearance, tumor rapid growth and cachexia respectively.
The urinary protein patterns on SDS-PAGE changes significantly as tumors progress. Urinary proteins were identified using an Orbitrap-Lumos mass spectrometry by label-free quantitation. Seven differential urinary proteins before tumor mass even palpable could be identified with a fold change >2 and p value <0.05. And these early changes in urine could also be identified at tumor mass appearance, tumor rapid growth and cachexia time points. Twenty-four differential proteins were annotated before as biomarkers of cancer and nine proteins as biomarkers of breast cancer. Additionally, it was found that those differential proteins were involved in several pathways related to cancer, including IL-6 and IL-12 signaling, production of nitric oxide and ROS and apoptosis. Finally, 30 dynamically changed urinary proteins were selected for validation by targeted proteomics. Our study suggested that urine is a sensitive biomarker source for early detection of cancer.