Screening of lung cancer biomarker-proteins with a multiplex electrochemical sensor system based on aptamers

The aim of this work is the development and demonstration of the method of simultaneous detection of several biomarkers of lung cancer in the blood plasma of patients using a multiplex electrochemical testing system based on DNA aptamers. DNA aptamers are a new class of synthetic affinity probes obtained by in vitro or in vivo selection procedure by the systematic evolution of ligands by exponential enrichment (SELEX). Materials and methods. A set of aptamers obtained previously by selection for postoperative lung cancer tissue was used to create a multiplex electrochemical biochip. Identification of aptamer target proteins was performed using a modified affinity enrichment method (AptaBID). Molecular targets for the used set of aptamers to lung cancer were defined as vimentin, defensin, a light chain of myosin, tubulin alpha 1-B, neutrophil elastase and Al elongation factor 1. Measurements of the presence of these biomarker proteins in blood plasma were carried out using electrochemical detection. The difference between peak heights before and after plasma deposition on the electrodes modified by aptamers was considered as a response of the system to the presence of protein onco-markers in blood plasma. Blood plasma of healthy volunteers was used as control. Results. Research showed that in the blood plasma of all the patients with lung cancer the content of biomarker proteins that bind to aptamers on electrode surfaces was increased. The increased content of these proteins in the blood plasma of patients suggests the presence of invasiveness and metastasis of tumors and their chemo-resistance.