ABSTRACT
BACKGROUND: Glypican-1 (GPC1) is expressed in pancreatic ductal adenocarcinoma (PDAC) cells and adjacent stromal fibroblasts. Recently, GPC1 circulating exosomes (crExos) have been shown to be able to detect early stages of PDAC. In this study, we investigated the usefulness of crExos GPC1 as a biomarker for PDAC. METHODS: Plasma was obtained from patients with benign pancreatic disease (n = 16) and PDAC (n = 27) prior to pancreatectomy, and crExos were isolated by ultra-centrifugation. Protein was extracted from surgical specimens (adjacent normal pancreas, n = 13; and PDAC, n = 17). GPC1 levels were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: There was no significant difference in GPC1 levels between normal pancreas and PDAC tissues. This was also true when comparing matched pairs. However, GPC1 levels were enriched in PDAC crExos (n = 11), compared to the source tumors (n = 11; 97 ± 54 vs. 20.9 ± 12.3 pg/mL; P < 0.001). In addition, PDACs with high GPC1 expression tended to have crExos with higher GPC1 levels. Despite these findings, we were unable to distinguish PDAC from benign pancreatic disease using crExos GPC1 levels. Interestingly, we found that in matched pre and post-operative plasma samples there was a significant drop in crExos GPC1 levels after surgical resection for PDAC (n = 11 vs. 11; 97 ± 54 vs. 77.8 ± 32.4 pg/mL; P = 0.0428). Furthermore, we found that patients with high crExos GPC1 levels have significantly larger PDACs (>4 cm; P = 0.012). CONCLUSIONS: High GPC1 crExos may be able to determine PDAC tumor size and disease burden. However, further efforts are needed to elucidate its role as a diagnostic and/or prognostic biomarker using larger cohorts of PDAC patients.
ABSTRACT
Hepatocyte growth factor (HGF) is a multifunctional cytokine with important roles in cell proliferation, survival, motility and morphogenesis. Secreted by cells of mesenchymal origin, HGF is the specific ligand for the tyrosine-kinase receptor c-MET (cellular mesenchymal-epithelial transition), also called MET, which is expressed in different types of epithelial, endothelial and haematopoietic progenitor cells. The HGF/MET axis is involved in several biological processes, such as embryogenesis, organogenesis, adult tissue regeneration (including wound healing and liver regeneration) and carcinogenesis, for both solid and haematological malignancies.(1 2) HGF and its particular interaction with the MET receptor have been extensively investigated in the last decades and remain the focus of numerous clinical trials.(3-8) This short review focuses on HGF structure and function, as well as its roles in liver regeneration and different types of tumours.
