Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

PURPOSE: Tumor hypoxia is associated with poor prognosis and resistance to treatment. Our aim was to assess the expression of proteins that act as cellular oxygen sensors, directly regulating the hypoxia inducible factor (HIF) pathway, i.e., prolyl hydroxylase domain proteins (PHD)-1, PHD-2, PHD-3, and FIH in pancreatic endocrine tumors (PET). EXPERIMENTAL DESIGN: Immunohistochemical expression of these markers was examined in 109 PET included in tissue microarrays and representing various stages of tumorigenesis. The results were correlated with histoprognostic factors including Ki-67 index, presence of a fibrotic focus, and microvascular density (MVD). RESULTS: The cytoplasmic and nuclear expressions of the three PHD isoforms were associated, and their expression was significantly higher in aggressive PETS, malignant, with lymph node metastases or with lower MVD. High nuclear expression of the three isoforms highly correlated with HIF-1alpha nuclear expression (P = 0.02, 0.003, and 0.006, respectively). Moreover, high nuclear PHD-1 or PHD-3 expression was associated with a poorer survival (P = 0.01). Cytoplasmic FIH was significantly higher in malignant PETs (P = 0.05) and in PETs with lymph node metastases (P = 0.02), and its expression correlated positively with those of cytoplasmic PHD isoforms (P < 0001). FIH stromal expression was found in 23% of PETs and correlated with higher FIH nuclear expression (P = 0.0004) and poorer disease-free survival (P = 0.0018). CONCLUSION: HIF regulatory proteins are highly expressed in PET and their expression is correlated with tumor metastases, tumor recurrence, and prognosis. These molecules that play an important role in the control of hypoxia-induced genes may have a function in the regulation of cellular proliferation and differentiation during endocrine tumorigenesis.

Original publication




Journal article


Clin Cancer Res

Publication Date





6634 - 6639


Adenocarcinoma, Adenoma, Islet Cell, Adult, Carcinoma, Pancreatic Ductal, Cell Differentiation, Cell Hypoxia, Cell Proliferation, Dioxygenases, Female, Follow-Up Studies, Gene Expression Regulation, Neoplastic, Humans, Hypoxia-Inducible Factor 1, alpha Subunit, Hypoxia-Inducible Factor-Proline Dioxygenases, Immunoenzyme Techniques, Liver Neoplasms, Lymphatic Metastasis, Male, Microcirculation, Mixed Function Oxygenases, Neoplasm Recurrence, Local, Neovascularization, Pathologic, Pancreatic Neoplasms, Procollagen-Proline Dioxygenase, Repressor Proteins, Tissue Array Analysis