Effects of ELAVL1 Inhibition on Emt Transcription Factors in Pancreatic Cancer Cells, in Vitro

Introduction Epithelial-to-mesenchymal transition (EMT) is a cellular process when epithelial cells lose their epithelial characteristics and acquire mesenchymal traits of migration and invasion. There are known EMT transcription factors (EMT TFs), such as SNAIL-1, SNAIL-2, ZEB1, ZEB2, and TWIST, that regulate EMT by controlling gene expression. ELAVL1 is an RNA-binding protein, also known as human antigen R, that selectively binds AU-rich (AREs) elements found in untranslated regions of mRNAs. This protein plays a key role in posttranscriptional gene regulation, which is dysregulated in pancreatic ductal adenocarcinoma (PDAC) cells. ELAVL1 participates in EMT regulation by stabilizing mRNAs of EMT TFs, which can promote cancer progression. Aim The aim of this study was to investigate the effects of ELAVL1 protein inhibition on EMT-TF RNA expression in different pancreatic cancer cell lines. Methods In this investigation cell lines such as BxPC-3 and MiaPaCa-2 were used. BxPC-3 is a cell line which exhibits epithelial morphology derived from primary pancreatic adenocarcinoma. MiaPaCa-2 is an epithelial cell line derived from adenocarcinoma metastatic to the liver. ELAVL1 protein was inhibited by dihydrotranshinone-I (DHTS) for 24 hours after which RNA was extracted, converted to cDNA and analysed by qRT-PCR method. Results The results showed that MiaPaCa-2 (advanced tumour) cells had higher ZEB1 (52-fold) and SNAIL-1 (18-fold) and lower ELAVL1 (76 %), ZEB2 (44 %) and SNAIL-2 (10 %) expression when compared to that of BxPC-3 cell line (primary cancer). When comparing the effects of ELAVL1 protein inhibition, the results show that it does not affect any investigated RNA expression in BxPC-3 cell line, however decreases all investigated RNA expression in MiaPaCa-2 cell line (ELAVL1 to 71%, ZEB1 to 50 %, ZEB2 to 47 %, TWIST to 48 %, SNAIL-1 to 59 %, SNAIL-2 to 65 %). Conclusions The EMT-TF expression levels of native cells show obvious differences between cell lines, however, the inhibition of ELAVL1 protein alters the expression of EMT-TF in cells from advanced PDAC while not altering the expression in cells from primary PDAC cancer. This suggests that inhibition of ELAVL1 could positively affect advanced PDAC, but further investigation is required.