Silencing of AHR and ELAVL1 genes influences post-transcriptional expression of each other and chemoresistance of pancreatic cancer cells, in vitro
Author(s) | |
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Matthews, Jason | University of Oslo, Institute of Basic Medical Sciences, Oslo, Norway |
Date Issued |
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2022-10-08 |
no. P0795
Poster Presentations. Pancreas
Bibliogr.: p. 960
Introduction: Pancreatic cancer (PC) is a devastating disease that has less than 10 % five-year survival rate [1]. There is an urgent need to find new therapies to treat PC patients. HuR protein (ELAVL1 gene) expression in cell cytoplasm is positively associated with PC response to gemcitabine which is currently first-line treatment for PC [2]. The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor that among other purposes modulates RNA-binding protein ELAVL1 signaling pathway by blocking HuR protein (ELAVL1) translocation from nucleus to cytoplasm which consequently leads to overexpression of cytoprotective, anti-apoptotic proteins and chemoresistance [3]. Overexpression of AHR leads to decreased cytoplasmic levels of HuR protein (ELAVL1) which in turn might contribute to chemoresistance of PC patients and their survival. Aims & Methods: The aim of this research was to investigate how AHR and ELAVL1 gene silencing affects the post-transcriptional expression of related genes, each other, and chemoresistance of PC cell lines. Three PC cell lines were used (T3M4, BxPc3, Su.86.86). AHR and ELAVL1 genes were silenced for 24-hours by lipofectamine mediated siRNA transfection. Afterwards the cells were treated with IC50 of gemcitabine for 48-hours (calculated for each cell line independently). After treatment gene expression was measured by RT-PCR and protein expression by Western Blot assay. Metabolic activity was measured by MTT assay. Results: The results showed that silencing of AHR and/or ELAVL1 resulted in decreased cell viability and increased sensitivity to gemcitabine in all three PC cell lines. Silencing of AHR gene resulted in increase of ELAVL1 RNA expression, however, HuR protein (ELAVL1 gene) expression was not affected by silencing of AHR. Silencing of ELAVL1 resulted in reduced AHRRNA as well as reduced AHR protein expression. Results show that AHR could be involved in regulation of ELAVL1 expression in post-transcriptional level and vice versa. The results of AHR and/or ELAVL1 gene silencing and expression of cytoprotective molecules of ELAVL1 pathway differed between cell lines. [...].