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

CD133 protein was detected after using demethylating agent 5-aza-2’-deoxycytidine.
Flowcytometric and western blot analysis showed that VPA treated culture increased
expression of CD133 protein to several folds and maintained it high as far as VPA is
included in the culture of SHSY5Y, UKF-NB3 NBL cell lines. On the other hand, Valpromid,
a carboxamide derivative of VPA that lack the histone deacetylase inhibition effect
doesn‘t induce CD133 expression in UKF-NB3 which confirms the regulation of CD133
by the state of histone.
We also highlight that hypoxia (1% oxygen) induced robust down regulation of CD133
up to disappearance of the protein expression in UKF-NB3 cell line. Hypoxia-inducible
factors seem to be involved in this regulation because the same effect was obtained
when cobalt chloride, that mimic hypoxia by inducing hypoxia-inducible factors, was
added to culture in normoxia. Moreover, the great effect of VPA on expansion of
CD133 in normoxia, was diminished in hypoxic condition and is regained again when
VPA is combined with 5-aza-2’-deoxycytidine, suggesting that part of the cells acquired
methylation of the CD133 promoter in hypoxic condition.
The regressive response of the amount of CD133 in hypoxia is unusual to CSCs behavior
in comparison to CD133 positive cells in other solid tumours (Soeda et al., 2009) that
is of great importance to understand the tumor microenvironment and the different
reaction of CD133 expression in various cell types in response to hypoxia. Obviously,
CD133 gene expression is directly controlled by epigenetic regulation.
Acknowledgments
This work was supported by GAUK grant No 620612 and GAČR No No P301/10/0356.
Refrences
Qianga L, Yanga Y, Ma YJ, et al.,: Isolation and characterization of cancer stem like cells in
human glioblastoma cell lines. Cancer Letters 279: 13–21 (2009).
Soeda A, Park M, Lee D, et al.: Hypoxia promotes expansion of the CD133-positive glioma
stem cells through activation of HIF-1a. Oncogene 28: 3949–3959 (2009).
Tabu K, Sasai K, Kimura T, et al.: Promoter hypomethylation regulates CD133 expression
in human gliomas. Cell Research 18:1037-1046 (2008).
Tong QS, Zheng LD, Tang ST, et al.: Expression and clinical significance of stem cell marker
CD133 in human neuroblastoma. World J Pediatr 4(1):58-62 (2008)
61. POPULATION DYNAMICS OF SP-PHENOTYPE UNDER IN VITRO CONDITIONS
Jaromír Mikeš, Jana Vargová, Lucia Mikešová, Zuzana Zsihovicsová, Ján Kovaľ, Rastislav
Jendželovský, Peter Fedoročko
Institute of Biology and Ecology, University of Pavol Jozef Šafárik in Košice, Slovak Republic;
jaromirmikes@yahoo.com
A concept of cancer cells with “mighty” powers of stem cells was primarily identified and
issued in haematological malignancies in 1990’s and it seems to be valid in solid tumour,
too. The main consequence accrued from this concept is the existence of rare cells,
aka “cancer stem-like cells” (cSCs), with a high resistance to anti-cancer therapy and
Analytical Cytometry VII 77