MIR-744 and MIR-30D act as tumour suppressors in pancreatic ductal adenocarcinoma

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and has one of the highest mortality rates and poorest prognosis among cancers. Unfortunately, the diagnosis of this cancer is often a lengthy process and requires invasive techniques like tissue biopsies and endoscopies, and the use of various imaging modalities that requires specialized training. The development of liquid biopsy, a non-invasive diagnostic technique that requires a simple blood test, would be beneficial to help diagnose PDAC. My research project aims to identify the biological significance of previously identified up- and downregulated miRNAs found in extracellular vesicles extracted from PDAC patient plasma compared to controls. First, a number of miRNA targets (n = 17) identified by small RNA sequencing in patient samples were validated by droplet digital PCR. Some of these miRNAs (n = 4) were then used to transfect one healthy (H6C7) and one cancerous cell line (PANC 10.05) with a mimic miRNA (increases abundance) and a siRNA (decreases abundance) for each target. The number of live cells was measured 72h post-transfection by flow cytometry. It was found that miR-744-5p mimic decreases the number of live cells (n = 3, P < 0.05), while miR-30d siRNA (n = 3, P < 0.05) increases the number of live cells. Interestingly, miR-744-5p mimic and miR-30d siRNA had no significant effect on the number of H6C7 cells. These results suggest that miR-744-5p and miR-30d may both be tumour suppressor miRNAs in pancreatic cancer.