Author: TOMAS MOCKAITIS
Dissertation title: Electrochemical methods for analysis of 3D cancer spheroids and enzyme activity
Fields of science: Chemistry N 003
Scientific supervisor: assoc. prof. dr. Inga Morkvėnaitė- Vilkončienė
Defence of the dissertation: 7 November 2025
SUMMARY: The rising global incidence of cancer remains a major public health challenge, with the World Health Organization projecting an increase in annual cases from 20 million in 2022 to 35 million by 2050. Despite rapid scientific progress, early diagnosis remains difficult because most tumors are asymptomatic at early stages and are therefore detected too late. This dissertation aims to develop a system for detecting the cancer biomarker Vanin-1 in blood and urine and for visualizing endogenous compounds released from spheroids of the MCF-7 human breast cancer cell line. The work is based on the synthesis and characterization of a new probe, VaninLP, enabling selective electrochemical detection of the enzyme Vanin-1, and on the development of an electrochemiluminescence (ECL) platform for monitoring metabolites released from cancer cell spheroids. The results show that VaninLP is the first electrochemical probe selective for Vanin-1 and achieves a limit of detection superior to comparable fluorescent labels. ECL analyses identified glutathione as the predominant released metabolite, with a minor amount of NADH also detected. These findings provide a basis for earlier and more accurate cancer diagnostics and for quantitative monitoring of therapeutic response..