Increased plasma microRNA and CD133/CK18-positive cancer cells in the pleural fluid of a pancreatic cancer patient with liver and pleural metastases and correlation with chemoresistance.

We report a case of notably increased plasma levels of microRNA (miR)-21, miR-25, miR-103 and miR-151 in a pancreatic cancer patient with liver and pleural metastases. CD45-coated immunomagnetic beads detected an enrichment of malignant cancer cells in the pleural fluid, and CD133(+)CK18(+) cancer cells were identified. Using computer tomography (CT) combined with cancer cells stained in the pleural fluid, a previously healthy 60-year-old male was diagnosed with pancreatic cancer with multiple liver tumor metastases. Cancer antigen 19-9 (CA19-9), alkaline phosphatase (ALP) and γ-glutamate-transpeptidase (γ-GT) were notably increased in the serum, and carcinoembryonic antigen (CEA) was increased in the pleural fluid. The patient succumbed to the disease three months following standard chemotherapy. The increased levels of plasma miR-21, miR-25, miR-103 and miR-151, as well as the identification of CD133(+)CK18(+) cells in the pleural fluid of a pancreatic cancer patient with liver metastases, may regulate the molecular mechanisms involved in chemoresistance. The patient was insensitive to chemotherapy and succumbed 3 months later. Full elucidation of the molecular and pathological features of pancreatic cancer may be a novel strategy for diagnosis and tailored therapy.