L.M. Zabegina1, M.A. Belyaev2, K.E. Katsuba1, A.V. Shalaev1, D.S. Plevako1, A.Yu. Garanin1, L.A. Logvin2, A.A. Svechkova2, V.V. Sharoyko2, A.V. Malek1

1The Petrov National Medicine Research Center of Oncology, Saint-Petersburg

2The Pavlov First St. Petersburg State Medical University, Saint-Petersburg

Malek Anastasiya V. ― Doct. of Sci. (Med.), Head of the Scientific Laboratory of Cellular Technologies with the Oncoendocrinology Group, transfusiologist of The Petrov National Medicine Research Center of Oncology

68 Leningradskaya Str., Pesochnyy settlement, Saint-Petersburg, 197758, Russian Federation, e-mail: anastasia@malek.com.ru


Goal ― evaluation of technical feasibility and clinical potential of the method of quantitative analysis of «marker» populations of small extracellular vesicles (SEV) in plasma and fluid of peritoneal lavage for the diagnosis of gastric cancer (GC).

Material. Biological samples of patients with a verified diagnosis of GC (n=21), patients with chronic cholecystitis (n=8) and healthy donors (n=6).

Methods. SEVs were isolated using ultracentrifugation and a two-phase polymer system, SEV size and concentration were determined using nanoparticle tracking analysis, the presence of specific «exosomal» markers in the vesicular membrane was investigated using flow cytometry, quantitative analysis of «marker» SEVs was performed using the previously developed AuNP-aptasensor. The technology of AuNP-aptasensor is based on the phenomenon of reversible inhibition of enzyme-mimetic activity of gold nanoparticles due to nonspecific sorption of DNA aptamers. We used five AuNP aptamers equipped with different DNA aptamers, which allowed us to analyze five different «marker» molecules in the vesicular membrane.

Results. A statistically significant difference in the number of «marker» SEVs in the plasma of patients with GC and healthy donors was revealed using five different AuNP-aptasensors. No difference was observed in the quantitative determination of «marker» SEVs in the peritoneal lavage fluid of patients with GC and patients with chronic cholecystitis. However, the number of «marker» SEVs in the peritoneal lavage fluid of a patient with GC correlated with the degree of tumor differentiation (G).

Conclusions. Analysis of «marker» SEVs in plasma using AuNP-aptasensor seems to be a promising method of screening or early diagnosis of GC (1); AuNP-aptasensor may be a suitable approach for quantification of «marker» SEV in peritoneal lavage fluid. This analysis can turn out as a method of additional assessment of GC patients in order to determine the risk of peritoneal dissemination and the optimal therapeutic strategy.

Key words: gastric cancer, nanovesicles, aptasensor.