Introduction: Newly-onset diabetes mellitus (DM) in middle-aged and older people may be an early symptom of pancreatic cancer (PC). However, sensitive markers for PC are still missing. MicroRNAs (miRNAs) play an important role in a cell response regulation. Significant changes in miRNA expressions were observed in cancers. Our goal was to compare expressions of selected miRNAs in patients with PC, DM and controls.
Methods: We enrolled 74 patients with PC (42/32, with/without DM), 29 type 2 diabetic patients and 17 controls. MicroRNA was determined in serum of all examined subjects. In 9 patients with PC the tumor was resected subsequently and after 3 months the measurements were repeated. We analyzed the expressions of 8 miRNAs that we had identified in a previous pilot study (miR-21, miR-30, miR-191, miR-192, miR-196, miR-200, miR-423, miR-454).
Results: MicroRNA expressions were significantly higher in patients with PC than in DM and controls: miR-192: 1.6 (1.2 to 2.0) vs 0.3 (0.2-0.4) vs 0.3 (0.2 to 0.5), p < 0.00001; miR-21: 1.4 (1.2-1.7) vs 0.3 (0.2 to 0.5) vs 0.5 (from 0.4 to 0.7), p < 0.00001, miR-200: 1.6 (1.1 to 2.3) vs 0.3 (0.3-0.4) vs 0.3 (0.2 to 0.4), p < 0.00001. No difference was observed between DM and controls, as well as between diabetic and non-diabetic patients within the PC group. There were no significant differences in miRNA expressions in 9 patients after pancreatic surgery. But there were significant interindividual differences.
Conclusion: Our data shows that miR-21, miR-192 and miR-200 could be used as new diagnostic markers for pancreatic cancer. A dynamics of these miRNAs could serve as a prognostic marker in patients after cancer removal. Futher prospective studies with newly-onset diabetic patients with no signs of malignancy will be needed to validate if suggested miRNAs could be used as early markers as well.