Wednesday, 11 July 2018

Clinical Chemistry


BACKGROUND: There is an urgent need for blood-based molecular tests to assist in the detection and diagnosis of cancers at an early stage, when curative interventions are still possible, and to predict and monitor response to treatment and disease recurrence. The rich content of proteins in the blood that are impacted by tumor development and host factors provides an ideal opportunity to develop noninvasive diagnostics for cancer.

CONTENT: Mass spectrometry instrumentation has advanced sufficiently to allow the discovery of protein alterations directly in plasma across no less than 7 orders of magnitude of protein abundance. Moreover, the use of proteomics to harness the immune response in the form of seropositivity to tumor antigens has the potential to complement circulating protein biomarker panels for cancer detection. The depth of analysis currently possible in a discovery setting allows the detection of potential markers at concentrations of less than 1 μg/L. Such low concentrations may exceed the limits of detection of ELISAs and thus require the development of clinical assays with exquisite analytical sensitivity. Clearly, the availability for discovery and validation of biospecimens that are highly relevant to the intended clinical application and have been collected, processed, and stored with the use of standard operating procedures is of crucial importance to the successful application of proteomics to the development of blood-based tests for cancer.

SUMMARY: The realization of the potential of proteomics to yield blood biomarkers will benefit from a collaborative approach and a substantial investment in resources.

For disease investigation, the profiling of blood constituents, notably serum and plasma, using protein characterization technologies holds long-standing interest because of the easy accessibility of this circulating fluid and its rich content of proteins that inform scientists about the health status of an individual. The available methodologies to analyze proteins have evolved dramatically over the past few decades. The initial method consisted of 1-dimensional protein separations, which was followed by the use of 2-dimensional polyacrylamide gel electrophoresis coupled with Edman sequencing. The advent of mass spectrometry, coupled with the sequencing of human and other genomes, has had a dramatic impact on the field of proteomics. The capabilities of current proteomics technologies in terms of coverage of the proteome and depth of analysis that can be achieved in a quantitative manner are truly astounding compared with just a decade ago. Recent advances include substantial increases in speed, analytical sensitivity, and dynamic range, and the availability of multiple fragmentation techniques. Equally important is orthogonal sample fractionation before mass spectrometry. Yet there remains a perception that proteomics technologies are inadequate to address the protein complexities inherent in cells, tissues, and biological fluids. Here we outline strategies for the application of proteomics to the development of blood-based cancer markers.


No comments:

Post a Comment