Electrochemotherapy is a treatment option, using electroporation in combination with cytotoxic drugs, either bleomycin or cisplatin, to achieve local tumor control. Bleomycin enters the cell through endocytic transfer proteins and cisplatin through copper channels and passive diffusion. Because the set of transport proteins is quite small, consequently the uptake of the cytostatic into the cell is also limited.The set of transporter proteins is quite small, therefore the uptake of cytostatics into the cell is limited. Electrochemotherapy is based on electrical pulses that destabilize the cell membrane in tumors and thus significantly increase the cellular uptake of hydrophilic cytostatics that have obstructed transport across the cell membrane. Bleomycin is an antitumor drug that stops cell division through the formation of DNA double strand breaks leading to cell death. Cisplatin, on the other hand, destroy cancer cells by damaging DNA with formation of DNA adducts, consequently inhibiting DNA synthesis and replication, and causing apoptotic cell death. The aim of the master's thesis was to determine the sensitivity of pancreatic cancer cells to electrochemotherapy with cisplatin or bleomycin. We also investigated whether the cytotoxic effect is enhanced when pancreatic cancer cells are treated with combined electrochemotherapy and sunitinib, as this has not been described in the literature to date. Sunitinib malate is an oxindole molecule known to selectively interact with intracellular sites of ATP receptor kinases such as VEGFR1–3, PDGFR, KIT, FLT3, and CSF1R. The cytotoxic effect of combined therapy was examined on the human BxPC-3 pancreatic cancer cell line. The PrestoBlueTM assay was used to determine the doubling time of the BxPC-3 cell line, which was equal to 48 hours (2 days). Most optimal cell growth was observed when we plated 2000 cells per well. We demonstrated that BxPC-3 cells were more sensitive to electrochemotherapy with bleomycin than with cisplatin. Combination of electrochemotherapy with the tyrosine kinase inhibitor sunitinib on pancreatic cancer cells had more pronounced cytotoxic effect than electrochemotherapy alone, only when bleomycin was used. Combination therapy of electrochemotherapy with 0.14 µM bleomycin and sunitinib in three different concentrations (2.5, 5 in 7.5 µM) had a synergistic effect. Given the positive in vitro results, it would make sense to test this type of treatment on a tumor model of the pancreas in vivo.
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