Investigation of WNT signaling pathway in Valproic acid-induced PANC-1 cells

Pancreatic ductal adenocarcinoma (PDAC) is defined as one of the most aggressive cancers worldwide with a 5-year survival rate of less than 8%. The facts that the disease is resistant to conventional treatment with aggressive tumor behavior in most individuals and the lack of markers compatible with early diagnosis, limit current effective treatment approaches to surgical intervention in suitable patients. Therefore, development of new strategies for the treatment of the disease has gained importance all over the world. Accordingly, studies have used PANC-1 cells in the ductal pancreatic cancer modeling stage and have shown that VPA induces apoptosis in these cells. In our study, IC50 value that shows the concentration of VPA that inhibits cell proliferation by 50%, is calculated using CFSE staining method. This IC50 value is supported by the apoptosis measurement made by Annexin V/PI staining. Afterwards, PANC-1 cells were exposed to the determined IC50 dose of VPA, and the expression levels of LEF1, AXIN1, CCND1 and CTNNB1 genes, as the main components of Wnt/Beta-catenin signal pathway, were determined by qRT-PCR method, utilizing 2-ΔΔCT analysis. IC50 value is calculated as 2,5 mM after proliferation analyses made in 48th hour. Determination of early apoptosis in cells exposed to 2,5 mM VPA in the apoptosis analyses confirmed the calculated IC50 value. No significant difference has been observed in the expression levels of AXIN1 and CTNNB1 genes after the application of VPA. A significant increase was observed in the expression levels of CCND1 ve LEF1 genes. These findings have shown for the first time that IC50 value can be calculated by combining the CFSE and annexin V/PI methods. In addition, VPA has been confirmed to inhibit division of cancer cells and induce apoptosis.