58
PROGRAMME AND ABSTRACT BOOK
ABS TRAC T BOOK
pression of epithelial markers E-cadherin and
?
-catenin and
mesenchymal markers vimentin and Slug.
In vitro migration experiments using prostate cancer cell
lines show that the effect of MDM2 expression on cell migra-
tion is cell type specific. While overexpression of MDM2 led
to a moderate inhibition of cell migration in BPH-1 CAFTD03,
opposite effect was observed in DU145, and no change in mi-
gration potential was detected in PC3 cells. In order to explain
the differences in migration phenotype, we studied subcellular
localization of both endogenous and overexpressed MDM2
and MDMX. Our data suggest that nuclear localization of both
MDM2 and MDMX correlates with anti-migratory properties of
overexpressed MDM2.
Altogether, our data demonstrate an association of the EMT
phenotype with deregulation of two important regulators of
the p53 tumor suppressor, MDM2 and MDMX, which leads to
context-dependent changes in cell behaviour.
This work was supported by grant no. P301/12/P407 of the
Czech Science Foundation; by grant no. NT13573-4/2012 of the
Ministry of Health of the Czech Republic; by the Academy of
Sciences of the Czech Republic, grant no. AV0Z50040702, and
by the project FNUSA-ICRC no. CZ.1.05/1.1.00/02.0123 from the
European Regional Development Fund.
19) Modulation of cell cycle leads to phenotypical
changes of prostate cancer cell lines
Pernicová Z.
1,2
, Slabáková E.
1,2
, Šimečková Š.
1,2,3
,
Fedr R.
1
, Remšík J.
1,3
, Kozubík A.
1,3
, Souček K.
1,2
1
Department of Cytokinetics, Institute of Biophysics,
Academy of Sciences of the Czech Republic, Brno,
Czech Republic
2
Center of Biomolecular and Cellular Engineering,
International Clinical Research Center, St. Anne‘s
University Hospital Brno, Brno, Czech Republic
3
Department of Experimental Biology, Faculty of Sciences,
Masaryk University, Brno, Czech Republic
Prostate cancer is one of the leading types of cancer in
men worldwide. Androgen deprivation therapy (ADT) is an
important treatment especially for advanced stages of prostate
cancer, achieved by androgen receptor blockade and/or medi-
cal or surgical castration. Although ADT is initially very effective,
treated tumors inevitably progress to androgen-independent
prostate cancer, which is currently incurable and fatal. The me-
chanism through which ADT causes androgen-independence
is therefore of high research interest.
One of the possible events contributing to the development
of androgen independence of originally androgen-dependent
prostate cancer cells is neuroendocrine transdifferentiation
(NED) and emergence of neuroendocrine (NE)-like cancer cells
after ADT. The action of androgens is dominantly mediated
through AR, which was shown to be a critical regulator of the
G1-S transition in prostate cancer cells. Prolonged cultivation
of prostate cancer cell lines in the absence of androgens leads
to cell cycle arrest associated with changes in expression of a
number of cell cycle regulators including family of cyclin D
proteins, cyclin dependent kinase 2 (Cdk2) and inhibitor of
Cdk p27Kip1.
Here we therefore focused on elucidating the role of cell
cycle modulation in promotion of NED of prostate cancer cells
using prostate cancer cell lines LNCaP and LAPC-4. First, we
tested involvement of family of cyclin D proteins, which are
down-regulated in response to androgen ablation. Although
decreased level of cyclin D1 and/or cyclin D3 led to modula-
tion of cell cycle, there was no induction of NED when levels
of NED markers were observed. Next, we focused on the role
of Cdk2, down-regulated by androgen depletion. Inhibition
of Cdk2 by inhibitor CVT-313 led to significant deregulation of
cell cycle, which was accompanied by increased level of NED
marker γ-enolase in LAPC-4 cells. Since CVT-313 can inhibit
activity of both Cdk2 and Cdk1 we focused on elucidating
whether inhibition of Cdk1, Cdk2 or both succeeded by cell
cycle deregulation contributes to promotion of NED. We used
RNA interference approach to down-regulate simultaneously
levels of Cdk1 and Cdk2. Furthermore we treated cells with
another inhibitors of Cdk1 (CGP74514A and RO-3306) and Cdk2
(NU-6140) and examined its effect on cell cycle deregulation
and possible promotion of NED.
Our results imply how modulation of cell cycle caused by
deregulation of several cell cycle regulators may affect promo-
tion of NED of prostate cancer cells.
This work was supported by grants IGA MZD NT13573-
4/2012, AV ČR M200041203, GA ČR P301/12/P407, HistoPARK
(CZ.1.07/2.3.00/20.0185), and by project FNUSA-ICRC
(no. CZ.1.05/1.1.00/02.0123) from the European Regional
Development Fund. Institutional support was provided by the
Academy of Sciences of the Czech Republic.
20) The role of EMT/MET in regulation
of phenotype of breast cancer cells
Remšík J.
1,2
, Slabáková E.
1,3
, Pernicová Z.
1,3
, Fedr R.
1
,
Šimečková Š.
1,2,3
, Suchánková T.
1
, Kozubík A.
1,2
,
Souček K.
1,3
1
Department of Cytokinetics, Institute of Biophysics,
Academy of Sciences of the Czech Republic, Brno,
Czech Republic;
2
Department of Experimental Biology, Faculty of Science,
Masaryk University, Brno, Czech Republic;
3
Center of Biomolecular and Cellular Engineering,
International Clinical Research Center, St. Anne´s
University Hospital Brno, Brno, Czech Republic
Unfolding the mechanisms of cancer cell plasticity might
contribute to future therapeutical approaches. Breast cancer
stem cells (BCSC) are suggested to be the drivers of metastasis,
resistance to chemotherapy and radiation. BCSC were previous-
ly shown to co-exist in diverse mesenchymal and epithelial sta-
tes in different tumor sites [1]. Mesenchymal state results from
