The cancer-testis antigens are a group of unrelated proteins aberrantly expressed in various cancers in adult somatic tissues. This aberrant expression can trigger spontaneous immune responses, a phenomenon exploited for the development of disease markers and therapeutic vaccines. However, expression levels often vary amongst patients presenting the same cancer type, and these antigens are therefore unlikely to be individually viable as diagnostic or prognostic markers. Nevertheless, patterns of antigen expression may provide correlates of specific cancer types and disease progression. This paper will describe the development and application of a novel, readily customizable cancer-testis antigen microarray platform, together with robust bioinformatics tools, which enable quantification of anti-cancer-testis antigen autoantibody profiles in patient sera. By exploiting the high affinity between autoantibodies and tumor antigens, our highly multiplexed protein microarray platform gives linearity of response over 4 orders of magnitude and an autoantibody quantitation limit in the pg/mL range.
By using oriented attachment of folded, recombinant antigens and a polyethylene glycol microarray surface coating, our platform gives minimal non-specific antibody binding. Unlike other proteomics methods, which typically use lower affinity interactions between monoclonal antibodies and tumor antigens for detection, the high sensitivity and specificity realized using our autoantibody-based approach may facilitate the development of better cancer biomarkers, as well as potentially enabling pre-symptomatic diagnosis. We will illustrate the usage of our platform by monitoring the time-dependent response of melanoma patient cohorts to an experimental therapeutic NY-ESO-1-based cancer vaccine, to combination BRAF and MEK inhibitor treatment, and to anti-CTLA4/anti-PD1 vaccination.
Citation Format: Jonathan Blackburn. A novel cancer-testis antigen protein microarray for autoimmune profiling in cancers: Diagnosis, stratification, and treatment monitoring [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr IA27.