Page 61 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

P21

Analysis of alpha-1 antitrypsin expression in multidrug resistant cell lines

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Mila Ljujic , Aleksandra Divac Rankov , Miodrag Dragoj , Sofija Jovanovic Stojanov
1 Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
2 Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia

Background: Identification of the signature molecular factors and transcriptional profiles involved in
therapy resistance is of vital importance in developing new strategies for treatments and disease
monitoring. Tumour secretome is a set of macromolecules secreted by tumour cells into the extracellular
space as a response to changes in tumour environment that at the same time shapes the microenvironment
further promoting specific phenotypes and contributing to cellular plasticity in tumour. Protein alpha-1
antitrypsin (AAT, encoded by SERPINA1 gene) is an acute phase protein that has emerged as one of the key
components in tumour secretome involved in crucial stages of tumour development and progression, with
recent data also implicating it in therapeutic resistance. However, what exactly leads to SERPINA1
upregulation during development of therapy resistance, as well as its biological significance in this process,
is still unclear. Our aim was to analyse SERPINA1 expression in multidrug resistant cell lines and 3D cellular
models. Expression of IL-6 was also analysed, as AAT is an acute phase reactant and its levels increase in
response to inflammatory cytokines. Patients and methods: We analysed SERPINA1 and IL-6 expression in
three different cell lines - human glioblastoma U87, non-small cell lung carcinoma NCI-H460 and colorectal
carcinoma DLD1 as well as their multidrug resistant counterparts U87-TxR, NCI-H460/R and DLD1-TxR,
respectively. In addition, expression analysis was performed in long-term 3D glioblastoma model of U87
cells cultured in alginate microfibers, and compared to long-term 2D cell culture of U87. Quantitative RT-
PCR was performed using Taqman gene expression assays and data were normalized to GAPDH. Results:
We found that SERPINA1 expression is significantly upregulated in all the multidrug resistant cell lines
analysed compared to their sensitive counterparts. Expression of IL-6 was significantly upregulated in U87-
TxR and DLD1-TxR compared to their parental lines, however NCI-H460/R cell line had lower IL-6 expression
compared to NCI-H460. In 3D glioblastoma model of U87 cells, previously found to exhibit increased
therapy resistance compared to 2D cell culture, both SERPINA1 and IL-6 expression were significantly
upregulated. Conclusion: Our results indicate that SERPINA1 expression correlates with therapy resistance
in analysed cell lines and 3D model of glioblastoma, revealing the potential of utilizing this molecule as a
biomarker of therapy resistance. However, transcriptional profiles connected to its expression in therapy
resistance still remain to be determined.
Key words: multidrug resistance, alpha-1 antitrypsin, biomarkers

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