Detection of circulating hypoxia-regulated miR-210 in pancreatic adenocarcinoma patients

Abstract

4624 Background: MicroRNAs (miRs) are small non-coding transcripts involved in many cellular mechanisms, including tumorigenesis. miR-210, in particular, has been shown to be induced by hypoxia, over-expressed in several different cancers, and correlated with adverse outcomes in breast cancer. Moreover, since pancreatic adenocarcinomas have been previously shown to be extremely hypoxic, we hypothesized that miR-210 may be elevated in the plasma of these patients compared to non-cancer controls. Here, we compared the circulating plasma levels of miR-210 in pancreatic cancer patients and controls using a novel miRNA extraction approach and quantitative PCR. Methods: Pretreatment EDTA plasma samples were obtained from pancreatic cancer patients and age-matched non-cancer controls. miRNA was extracted from 40ul of plasma and reverse transcribed to cDNA. A known quantity of c. elegans miR-54 was added to the sample as a normalization control. miR-210 and cel-miR-54 were then quantified using TaqMan MicroRNA Assays. The procedure was performed on the initial 11 pairs of age-matched pancreatic cancer patients and non- cancer controls, then validated with a second cohort of 12 pancreatic cancer patients and 11 controls. Results: miR-210 was reliably detected and quantified in small amounts of plasma using the approach developed in our study. There is a statistically significant four-fold increase of mir-210 expression in pancreatic cancer patients compared to normal controls (Student's t-test, p <0.0001). This difference was confirmed in the validation group (Student's t-test, p<0.05). Conclusions: Circulating miR-210 levels can be readily measured from a small quantity of plasma using a novel extraction method. Its expression is significantly higher in the blood of pancreatic cancer patients compared to controls and may potentially serve as a useful biomarker for pancreatic cancer diagnosis. No significant financial relationships to disclose.