Page 47 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

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The effect of osteogenic differentiation on oral cancer stem cells’ miR-21 and miR-133
expression

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Milica Jaksic Karisik , Milos Lazarevic , Dijana Mitic , Maja Milosevic Markovic ,
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Jelena Milasin
1 Department of Human Genetics, School of Dental Medicine, University of Belgrade

Background: Cancer stem cells (CSCs) are frequently associated with initiation and progression of various
tumors, including oral squamous cell carcinoma (OSCC). CD44 has been documented as oral CSC surface
marker and has been used for the detection and isolation of oral CSCs. CSCs possess the potential to
transdifferentiate into different cell lineages, as do normal adult stem cells. Such plasticity of CSCs is
considered to be a promising therapeutic tool. Recent studies suggest that microRNAs (miRNAs) can
regulate CSCs at a molecular level and are associated with different cancer properties. This study focused
on the most common oncogenic microRNA miR-21, frequently upregulated in a variety of cancers and miR-
133a which acts as a tumor suppressor. The aim of this study was to examine levels of miR-21 and miR-133
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after osteogenic differentiation of CD44 cells isolated from OSCC cell line SCC-25. Materials and methods:
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CD44 cells were magnetically separated using magnetic-activated cell sorting system. CD44 cells were
seeded onto 24-well culture plates (8×10 per well) and cultured in osteogenic differentiation medium for
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21 days. Cells were cultivated under standard conditions in humidified atmosphere with 5% CO2 at 37°C.
After 21 days, total RNA was extracted from the culture cells with TRIzol Reagent. Reverse transcription of
microRNA was performed using TaqMan MicroRNA Reverse Transcription Kit in accordance with the
manufacturer’s instructions. MiRNA expression was normalized to RNU6. Results: After osteogenic
differentiation, expression levels of miR-21 were significantly lower compared to uninduced cells. The levels
of miR-133, on the opposite were significantly higher compared to uninduced cells. Conclusion: This study
suggests that osteogenic differentiation of oral CSCs significantly down-regulates the oncogenic miR-21 and
up-regulates the tumor-suppressor miR-133, which are both favorable effects in terms of potential cancer
treatment.

Keywords: oral squamous cell carcinoma, cancer stem cells, miR-21, miR-133, osteogenic differentiation.

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