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

Our results show that both p38α +/+ and p38α -/- cells are able to be directed to
hematopoietic cell lineages. However p38α deficient cells undergo hemasopoiesis more
intensively in contrast to their wild-type counterpart. P38α -/- cells also in higher ratio
form erythroid and granulopoietic lineages. In contrast, wild-type cells are able to better
maintain CD34 positive cell sub-population. Thus based on our preliminary data we can
hypothesize that depletion of p38α MAPK leads both to attenuating stemness and to
enhancing myeloid progenitor´s development.
Acknowledgments
This work was supported by grants from MEYS CR MSM0021622430 and Cost CZ
LD11015, from GAČR 13-29358S, and from the European Social Fund - projects
OganoNET (CZ.1.07/2.4.00/31.0245) and HistoPARK (CZ.1.07/2.3.00/20.0185). LK was
supported by the European Regional Development Fund - Project FNUSA-ICRC (No.
CZ.1.05/1.1.00/02.0123).
References
Geest CR. Coffer PJ.: MAPK signaling pathways in the regulation of hematopoiesis., J
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Ito, K., Hirao, A., Arai, F., Takubo, K., Matsuoka, S., Miyamoto, K., Ohmura, M., Naka, K.,
Hosokawa, K., Ikeda, Y., Suda, T.: Reactive oxygen species act through p38 MAPK to limit
the lifespan of hematopoietic stem cells., Nat. Med. 12, 446–451, 2006
P89. HYPERICIN SUPPRESSES “SIDE POPULATIONS” BUT STIMULATES AGGRESSIVE
PHENOTYPE IN A549 HUMAN LUNG ADENOCARCINOMA CELLS
Jana Vargová, Jaromír Mikeš, Lucia Mikešová, Zuzana Zhihovicsová, Peter Fedoročko
P. J. Šafárik University in Košice, Faculty of Science, Institute of Biology and Ecology,
Košice, Slovak Republic; jana.vargova1@student.upjs.sk
Causes of tumor resistance to therapy and/or relapses are of major interest in cancer
research, recently. These issues represent the most serious aspects of cancer. In the
light of the latest findings, they are being linked with existence of small fraction of
cells resembling stem cells with their nature, called cancer stem-like cells (CSC). One
of methods for detection of CSC is the so called “Side population” (SP) technique. It
is based on ability of certain cells to get rid of xenobiotics, including fluorescent dye
Hoechst 33342. From molecular point of view, this phenomenon is associated with
elevated expression of ABC-transporter molecules, above all ABCG2 (BCRP) (Zhou et al,
2001).
Hypericin (HYP) is compound commonly found in St. John’s Wort (Hypericum perforatum).
HYP has been widely used in combination with photodynamic therapy. However, it has
been shown that HYP possess some antitumor activity in the dark, too (Blank et al.,
2004). HYP was suggested as a potential substrate of ABC-molecules, mostly MRP1 and
BCRP. Moreover, HYP per se stimulated expression of MRP1 and BCRP in HT-29 cells
(Jendzelovsky et al., 2009).
The aim of our study was to explore the effect of non-photoactivated HYP on
194 Analytical Cytometry VII