# MicroRNA-26a-5p is a reliable biomarker in the adjuvant setting for pancreatic ductal adenocarcinoma

## TL;DR

This study identifies miR-26a-5p as a potential blood-based biomarker to predict chemosensitivity and improve outcomes in pancreatic cancer patients after surgery.

## Contribution

The study introduces miR-26a-5p as a novel blood biomarker for predicting chemosensitivity in pancreatic ductal adenocarcinoma patients.

## Key findings

- miR-26a-5p expression inversely correlates with chemosensitivity in vitro and in clinical samples.
- High miR-26a-5p levels in blood after surgery are associated with longer survival after recurrence.
- miR-26a-5p is a candidate biomarker for managing adjuvant chemotherapy in PDAC patients.

## Abstract

Pancreatic ductal adenocarcinoma (PDAC) has a high recurrence rate even after radical resection because of subclinical tumors. To manage them, a reliable biomarker that can indicate the presence of subclinical tumors and predict their chemosensitivity is required. This study aimed to identify a miRNA as a biomarker that can be used to individualize postoperative adjuvant chemotherapy using postoperative peripheral blood samples. Integrating miRNA microarray data from the blood of 18 patients with PDAC and the in vitro results regarding the phenotypes of chemoresistant PDAC cells, a candidate miRNA was identified. The relationships between candidate miRNA expression and chemosensitivity were examined in vitro and in clinical samples from other cohorts of 33 patients with recurrence. Comprehensive analyses of blood samples detected 5 candidate miRNAs. Of these, miR-26a-5p was considered a candidate biomarker of chemosensitive phenotypes. In validation experiments, chemosensitivity was inversely correlated with miR-26a-5p expression in vitro. Moreover, the ability of miR-26a-5p to predict chemosensitivity was clinically evaluated using blood samples. Patients with high miR-26a-5p expression in the blood after radical resection exhibited a significantly longer survival time after recurrence. Thus, we concluded that miR-26a-5p is a potentially useful biomarker for managing patients with PDAC, especially those undergoing adjuvant chemotherapy.