Figure 3

Investigation into whether plasma miR-107 levels reflect tumor dynamics in plasma, pancreatic tissue and exosomes. (a) Comparison of miR-107 expression between normal and cancerous pancreatic tissues. The expression of miR-107 was significantly higher in 6 normal pancreatic tissues than in 6 cancerous pancreatic tissues (P = 0.0272). (b) miR-107 plasma levels in pre- and postoperative samples from PCa patients who underwent curative pancreatectomy. miR-107 plasma levels in paired samples collected before and nearly 1 month after surgery from 10 PCa patients who underwent curative pancreatectomy. Plasma miR-107 was significantly elevated in the postoperative plasma samples (P = 0.0186). (c) miR-107 expression level in exosomes extracted from the plasma of PCa patients and healthy volunteers. The expression level of miR-107 in exosomes extracted from plasma was investigated in 4 PCa patients and 4 healthy volunteers. Exosomal miR-107 in plasma was significantly down-regulated in PCa patients compared with healthy volunteers (P = 0.0222). (d) Decreased plasma miR-107 is associated with prognostic outcomes in PCa patients. A prognostic analysis revealed that a low miR-107 plasma level was significantly associated with a worse cause-specific survival rate in all PCa patients (P < 0.0001), a worse cause-specific survival rate in PCa patients with curative pancreatectomy (P = 0.0038), and a worse disease-free survival rate in PCa patients with curative pancreatectomy (P = 0.0159).