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Volume 9, Issue 5 (Suppl)
J Cancer Sci Ther, an open access journal
ISSN: 1948-5956
Cancer Stem Cells and Oncology Research 2017
June 26-28, 2017
Page 42
10
th
International Conference on
June 26-28, 2017 London, UK
CANCER STEM CELLS AND
ONCOLOGY RESEARCH
Capicua regulates self-renewal and tumour progression of breast cancer cells
Jeehyun Yoe
Pohang University of Science and Technology, Korea
C
ancer stem cells (CSCs) are capable of tumour initiation and growth, and play a critical role in metastasis, therapeutic resistance,
and disease recurrence in breast tumours. Therefore, if cancer arises and is maintained by the small population of CSCs within
the bulk tumours, it is of central importance that definitive marker genes for CSCs are identified and regulatory mechanisms that
promote stem cell maintenance be understood. Here, we show that the developmentally regulated HMG-box protein Capicua
(CIC) is a transcriptional repressor that suppresses CSC properties in both the luminal and basal/myoepithelial subtypes of breast
cancer cells. Mammosphere formation in culture was used to reveal stem cell properties, where expression of CIC was consistently
down regulated in primary mammospheres in comparison to parental adherent cells then in secondary mammospheres upon serial
passage. Knockdown of CIC increased mammosphere formation, while CIC overexpression prevented mammosphere formation,
effect dependent on continuous CIC expression. Furthermore, CIC knockdown MCF7 and MDA-MB-231 breast cancer cells
contained a higher percentage of EpCAM
+
/CD44
+
/CD24
low/
cancer-initiating cells than in control cells grown as monolayer cultures
and propagated as mammospheres. Loss of CIC relieved repression of
PEA3
group genes, especially
ETV4,
which was necessary and
sufficient for driving mammosphere formation. Moreover, we observed upregulation of the pluripotency-associated transcriptional
factor SOX2 in MCF7 CIC knockdown cells and demonstrated significant rescue effect on mammosphere formation following SOX2
knockdown in CIC knockdown cells. Therefore, we propose CIC as a potential biomarker of breast cancer stem cells and a novel target
in stem cell and cancer therapy.
Biography
Jeehyun Yoe is a PhD candidate with particular interests in Stem Cell and Cancer Biology. Her current research has 2 aims: 1) to better understand the role of CIC
in tumourigenic process in different cellular contexts and environments and 2) to further identify the molecular mechanisms that regulate CSC characteristics. Prior
to enrolling at POSTECH for the combined MS and PhD program, she graduated with a BS in Biology and minors in Chemistry and Music from the University of
North Carolina at Chapel Hill, USA.
jhyoe@postech.ac.krJeehyun Yoe, J Cancer Sci Ther 2017, 9:5(Suppl)
DOI: 10.4172/1948-5956-C1-102