ONE STEP HISTOLOGICAL DETECTION AND STAINING OF THE PTEN TUMOR SUPPRESSOR PROTEIN BY A SINGLE STRAND DNA

GLORIA LONGINOTTI; JUAN SEBASTIAN YAKISICH; MARIANO GRASSELLI; MARTÍN RADRIZZANI

Virginia

Simposio; VirginiaDrugDiscoveryRx A Symposium on CoronaVirus Therapeutics, Present and Future; 2021

Virginia Drug Discovery Consortium and Virginia Bio

Antibodies are the most used technological tool in histochemistry. However, their standardizationis difficult due to variation of biological systems as well as to variability due to the affinity and amplification of the signal arising from secondary peroxidase detection systems. In this article we combined two synthetic aptamers to facilitate the standardization of a detection protocol of protein markers in histological sections. The first aptamer, a 50-base single-stranded DNA fragment, which recognizes a PTEN tumor suppressor was combined to another single stranded 18-base aptamer DNA fragment, which forms a quadruplex structure guanine box. This second aptamer recognizes and attaches a molecule of hemin, increasing the catalytic capacity for the hydrogen peroxide. We demonstrated that the correct structural design of DNA combining an aptamer together with the peroxidase-like DNAzyme allowed the detection of proteins in histological sections. This is the first time that reproducible results have been presented in histological sections staining a cancer marker using a single-stranded DNA molecule with dual function. This technology due to its synthetic nature and its 1:1 antigen:enzyme ratio offers a versatile tool for the quantitative and qualitative detection of proteins markers.