Research Project

Website: http://www.stemspec.ca

Summary

Diagnosing a disease is most difficult at the early stages, where therapeutic intervention is most effective and least devastating. A patient’s sample contains many different cells, each of which can be distinguished and identified by the biomarkers (proteins, genes and small molecules) that comprise the cell’s biochemical signature. Groundbreaking research in leukemia has advanced the belief that a particular disease may be sustained by only a small fraction of the diseased cells (“cancer stem cells” in the case of cancer), and is thus particularly difficult to detect and treat. The biomarker signature also reflects biochemical processes within the cells that determine cell activity and fate. Accordingly, the capability to measure the full signature of biomarkers at the same time for individual cells provides an opportunity for improved understanding of cell genesis and for the development of drugs to treat the disease.

Enormous progress is being made on the identification of diagnostic biomarker signatures and the understanding of biomarker interactions. Unfortunately, there are few analytical tools capable of recognizing these signatures, and these have serious limitations for detecting many biomarkers in a single analysis. Current single cell diagnostic technologies are based on the detection of fluorescent emission from tagged reagents that specifically recognize the biomarkers. While up to 10 detection channels can be monitored simultaneously, the approach is limited by poor resolution. This results in signal overlap and large errors when biomarkers are present over a wide range of concentrations. There is a clear need for a new technology that will provide for the simultaneous quantitative and independent determination of many (up to 100) biomarkers in individual cells, especially where that analysis can be performed at high speed so that 1000 or more cells can be analyzed per second.

An innovative solution to this challenge has been developed in this project and is receiving considerable enthusiasm from the scientific community. The approach takes advantage of the high resolution of mass spectrometry to distinguish biologically-rare metal atoms that replace the fluorescent dyes in current use. A new generation of diagnostic reagents that bind different metals to biomarkers has also been developed. These “tagging metals” are detected with high sensitivity, high resolution, and in a quantitative manner by a prototype instrument. This “mass cytometer” introduces individual cells at a rapid rate, up to 1000 cells per second, to a multichannel mass spectrometer analyzer.

The goal of this Genome Canada project was to introduce successful analytical tools based on metal-tagging technology to the general research community for widespread diagnostic and research use. During the course of the project, a complex research prototype instrument and the reagents required for its operation were converted into a more user-friendly format. The team’s ambitious goals were realized in 2009, when sales of prototype instruments and reagents were made to early adopters.

In addition to enabling genomics and proteomics researchers to achieve a vast improvement in the depth and range of cellular analysis, the outcomes of this project have the potential to provide a diagnostic tool that will define the new standard-of-care benchmark in hospitals, clinics and research departments world-wide. The success of this project could lead to healthcare savings for Canadians and others, resulting from first-time-correct diagnosis and reduction in adverse drug reactions. It will advance international awareness of Canada as a leader in bioanalytical research. The commercial development of this mass spectrometer-based flow cytometer with its unprecedented multiplexing capabilities, along with its associated reagents technology development, will lead to many new highly-skilled jobs for Canadians and create millions of dollars of new revenue, much of it derived from export sales.

Significant Outcomes to Date

• MAXPAR™ reagents, formatted for both mass cytometry and conventional ICP-MS, were commercially launched (on the DVS Sciences website) in June 2009.
• The CyTOF™ cell analyzer was commercially launched at the GLIIFCA 2009 meeting (Pittsburgh, Oct. 2-4, 2009).

Notable Publications
D. R. Bandura, D.R., Baranov, V.I., Ornatsky, O.I., Antonov, A., Kinach, R., Lou, X., Pavlov, S., Vorobiev, S., Dick, J.E.  and Tanner, S.D. 2009. Mass Cytometry: Technique for Real Time Single Cell Multitarget Immunoassay Based on Inductively Coupled Plasma Time-of-Flight Mass Spectrometry, Analytical Chemistry, 81(16): 6813-6822.

Ornatsky, O.I., Kinach, R., Bandura, D.R., Lou, X., Tanner, S.D., Baranov, V.I., Nitz, M., and Winnik, M.A.  2008. Development of analytical methods for multiplex bio-assay with inductively couple plasma mass spectrometry.  Journal of Analytical Atomic Spectrometry 23(4): 463-469

Tanner, S.D., Bandura, D.R., Ornatsky, O., Baranov, V.I., Nitz, M., and Winnik, M.A.  2008. Flow cytometer with mass spectrometer detection for massively multiplexed single-cell biomarker.  Pure and Applied Chemistry 80(12): 2627-2641