ABSTRACTS – ORAL PRESENTATIONS - AMCA, spol. s r.o.

P79. NEW TYPE OF PHOTOSENSITIZER IS EFFECTIVE ALSO FOR THE RESISTANT
TUMORS
Alžbeta Grolmusová 1 , Pavel Abaffy 1 , Helena Paulíková 1 , Lýdia Čižeková 1 , Zuzana Ipóthová 2 ,
Ľubica Hunáková 3
1
Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology,
Slovak University of Technology, Bratislava, Slovak Republic;
alzbeta.grolmusova@gmail.com
2
Department of Chemical and Biochemical Engineering, Faculty of Chemical and Food
Technology, Slovak University of Technology, Bratislava, Slovak Republic
3
Cancer Research Institute, Slovak Academy of Science, Bratislava, Slovak Republic
Photodynamic therapy (PDT) represents a new alternative for the treatment of cancer.
PDT uses a drug, called a photosensitizer (PS), oxygen and light with appropriate
wavelength. When photosensitizers are exposed to the light with specific wavelength,
they produce free oxygen radicals that kill nearby cells (Robertson et al., 2009). Except
for classic porphyrin´s PSs, attention is also focused on non-porphyrin photosensitizers
such as anthraquinones, anthrapyrazols, xanthines, acridines or cyanines (Diwu and
Lown, 1994).
Recently, our in vitro experiments have showed that one group of acridine derivatives
– 1’,1’’-(acridine-3,6-diyl)-3’,3’’-dialkyldithiourea hydrochlorides (AcrDTUs) generated
oxygen free radicals after irradiation, what is one of the basic properties of each PS.
In the present study, photocytotoxic effect of AcrDTU on a resistant line A2780/CP has
been evaluated and compared with the effect on parental cell line A2780.
The analysis of the photocytotoxicity of AcrDTUs showed (viability of ovarian cancer
cell lines was monitored by MTT assay) that their effect was comparable for sensitive
and resistant cells lines. After irradiation (365 nm, 1.05 J/cm2), propyl-AcrDTU (5 µM)
decreased viability of sensitive and resistant cells about 95 % and 90 %, respectively.
The photocytotoxicity was accompanied with changes of cell morphology. When cells
were incubated with 0.5 µM propyl-AcrDTU and irradiated (365 nm, 1.05 J/cm2), the
lost of typical cellular shape and shrinkage of cells was observed (2 h-treatment). Such
changes of cytomorphology are typical hallmarks of apoptosis. Furthermore, generation
of “DNA-ladder” (oligonucleosomal double-strand DNA fragments) has been confirmed
after irradiation (365 nm, 1.05 J/cm2) and incubation of sensitive and resistant cell lines
with 0.5 µM propyl-AcrDTU for 4 h. Cell cycle analysis (flow cytometry) revealed the
accumulation of A2780 cells at the subG0 phase in a dose-dependent manner.
To reveal the mechanism of apoptosis, the intracellular localization of AcrDTU derivatives
in the A2780 and A2780/CP cell lines was monitored (ImageStream Imaging Flow
Cytometer).
Acknowledgements
This work was supported by STU Grant for Young Researchers 1327.
184 Analytical Cytometry VII