One Step Histological Detection and Staining of the PTEN Tumor Suppressor Protein by a Single Strand DNA

LONGINOTTI, GLORIA; YBARRA, GABRIEL; VIGHI, SUSANA; PERANDONES, CLAUDIA; MONTSERRAT, JAVIER; YAKISICH, JUAN SEBASTIAN; GRASSELLI, MARIANO; RADRIZZANI, MARTIN

Diagnostics

MDPI

Año: 2021 vol. 11

Abstract: Antibodies are the most used technological tool in histochemistry. However, even withmonoclonal antibodies, their standardization is difficult due to variation of biological systems aswell as to variability due to the affinity and amplification of the signal arising from secondaryperoxidase detection systems. In this article we combined two synthetic molecules to facilitatethe standardization of a detection protocol of protein markers in histological sections. The firstmolecule was an aptamer, a 50-base single-stranded DNA fragment, which recognizes a PTENtumor suppressor. The second molecule used was also another single stranded 18-base aptamerDNA fragment, which forms a quadruplex structure guanine box. This G-quadruplex recognizesand attaches a molecule of hemin, increasing the catalytic capacity for the hydrogen peroxide. Ourresults show how the correct structural design of DNA combining an aptamer together with theperoxidase-like DNAzyme allows to detect proteins in histological sections. This tool offers thestandardization of the detection of prognostic markers in cancer, in quality and quantity, due toits synthetic nature and its 1:1 antigen:enzyme ratio. This is the first time that reproducible resultshave been presented in histological sections staining a cancer marker using a single-stranded DNAmolecule with dual function.