iTRAQ-Labeling for Biomarker Discovery
Various mass-tagging approaches have been developed over the last few years that have enabled mass spectrometry-based relative and absolute quantification of proteins from complex samples. This, in turn, has facilitated proteomics research to address issues ranging from alterations in the proteome of various model systems in response to various stimuli to biomarker discovery studies. Here we describe the use of one such mass-tagging approach, viz., iTRAQ labeling, as applied to cancer biomarker discovery. When applied to a cohort of tens of clinical samples, this technology can provide useful leads that serve as a basis for a more targeted validation-scale study.
Key wordsiTRAQ-labeling LC-MS/MS analysis Trypsin digestion Relative quantification Strong cation exchange Reversed phase Mass-tagging Biomarker discovery
We thank the Canadian Cancer Society Research Institute and the Canadian Institutes of Health Research for funding research that enabled the development and application of the iTRAQ technology. We also acknowledge the collaboration of our biomedical and clinical colleagues, especially Terence J. Colgan, Ranju Ralhan, Ian J. Witterick, Christina M. MacMillan, and Iona T. Leong (Mount Sinai Hospital, Toronto); Alexander D. Romaschin and George M. Yousef (St. Michael’s Hospital, Toronto); and the late Abhijit Guha and Gelareh Zadeh (Hospital for Sick Children and Western Hospital, Toronto).
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