Expression of Key Hypoxia Sensing Prolyl-hydroxylases PHD1, -2 and -3 in Pancreaticobiliary Cancer

Aims: Tumour hypoxia is associated with an aggressive phenotype and resistance to chemotherapy and radiotherapy. The aim was to investigate whether key hypoxia sensing prolyl hydroxylases PHD1, PHD2 and PHD3 are dysregulated in pancreaticobiliary cancers, and to evaluate their potential clinical significance.

Methods And Results: Formalin-fixed human pancreatic tissue from 120 consecutive patients undergoing pancreatic resections between June 2001 and June 2006 was constructed into tissue microarrays. Expression of PHD1, PHD2 and PHD3 was analysed using immunohistochemistry and correlated with clinicopathological variables and disease-specific overall survival. PHD1, PHD2 and PHD3 were significantly overexpressed in pancreaticobiliary tumours compared with normal pancreatic ductal tissues (P = 0.03, P < 0.0001 and P < 0.0001, respectively). PHD3 expression in tumour tissue was associated with a trend towards worse overall disease-specific survival in ampullary adenocarcinomas (P = 0.035) and pancreatic adenocarcinomas (P = 0.084). Absence of PHD1 expression was significantly associated with perineural invasion in pancreatic adenocarcinomas (P = 0.02) and a trend towards significance was also seen for absence of PHD2 expression in pancreatic adenocarcinomas (P = 0.04).

Conclusions: Our results provide the first clinical evidence that PHD1, PHD2 and PHD3 may be involved in pancreaticobiliary tumorigenesis.