Page 64 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

P24

MiR-93-5p expression in response to the systemic, targeted, and combinational therapy for
metastatic colorectal cancer and therapy resistance: in vitro analysis

1
Jovana Despotović , Zoran Krivokapić 2,3,4 , Aleksandra Nikolić 1
1 Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
2 Clinic for Digestive Surgery, Clinical Center of Serbia, Belgrade, Serbia
3 School of Medicine, University of Belgrade, Belgrade, Serbia
4 Serbian Academy of Sciences and Arts, Belgrade, Serbia

Background: Addition of a targeted agent bevacizumab to the systemic chemotherapy (5-fluorouracil (5-
FU) combined with oxaliplatin) improves the survival of metastatic colorectal cancer (mCRC) patients.
However, half of them do not respond to therapy, so a challenge remains to identify treatment response
biomarkers. The expression of microRNAs has been associated with the therapeutic response and
resistance in CRC. The aim of this study was to analyze the miR-93-5p expression in response to the
systemic, targeted, and combinational therapy for mCRC and its potential role in therapy resistance.
Material and Methods: Human metastatic colon adenocarcinoma SW620 cells and colonic epithelial
progenitor HCEC-1CT cells were treated with FOX (21.4 μM 5-FU + 85 μM oxaliplatin) and/or 25, 85 and
250 µg/mL bevacizumab for 72 h. Cell response was evaluated through cell viability using MTT assay, while
miR-93-5p expression was analyzed by quantitative reverse transcription polymerase chain reaction.
Expression of hsa-miR-93-5p was also analyzed in 5-FU-resistant SW620 cells. Results: FOX and FOX/250
µg/mL bevacizumab treatments significantly reduced viability of SW620 and HCEC-1CT cells. Increasing
concentrations of bevacizumab alone or in combination with FOX reduced the viability of HCEC-1CT cells.
FOX and FOX/250 µg/mL bevacizumab combination significantly decreased miR-93-5p expression in HCEC-
1CT cells, but not in SW620 cells. Expression of miR-93-5p was similar in SW620 cells compared to the 5-
FU-resistant SW620 cells. Conclusion: Combination of targeted and systemic treatment for mCRC affects
SW620 viability, but not miR-93-5p expression. MiR-93-5p was not associated with 5-FU resistance. Thus,
miR-93-5p does not have a role in therapy response or resistance in mCRC.
Keywords: metastatic colorectal cancer, chemotherapy, bevacizumab, hsa-miR-93-5p
Acknowledgement: This study was funded by the Serbian Academy of Sciences and Arts [F-69].

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