Prolyl-4-hydroxylase PHD2- and hypoxia-inducible factor 2-dependent regulation of amphiregulin contributes to breast tumorigenesis.
Hypoxia-elicited adaptations of tumor cells are essential for tumor growth and cancer progression. Although ample evidence exists for a positive correlation between hypoxia-inducible factors (HIFs) and tumor formation, metastasis and bad prognosis, the function of the HIF-α protein stability regulating prolyl-4-hydroxylase domain enzyme PHD2 in carcinogenesis is less well understood. In this study, we demonstrate that downregulation of PHD2 leads to increased tumor growth in a hormone-dependent mammary carcinoma mouse model. Tissue microarray analysis of PHD2 protein expression in 281 clinical samples of human breast cancer showed significantly shorter survival times of patients with low-level PHD2 tumors over a period of 10 years. An angiogenesis-related antibody array identified, amongst others, amphiregulin to be increased in the absence of PHD2 and normalized after PHD2 reconstitution. Cultivation of endothelial cells in conditioned media derived from PHD2-downregulated cells resulted in enhanced tube formation that was blocked by the addition of neutralizing anti-amphiregulin antibodies. Functionally, amphiregulin was regulated on the transcriptional level specifically by HIF-2 but not HIF-1. Our data suggest that PHD2/HIF-2/amphiregulin signaling has a critical role in the regulation of breast tumor progression and propose PHD2 as a potential tumor suppressor in breast cancer.
Bordoli
M R
MR
Institute of Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland.
Stiehl
D P
DP
Borsig
L
L
Kristiansen
G
G
Hausladen
S
S
Schraml
P
P
Wenger
R H
RH
Camenisch
G
G
D066258:Amphiregulin; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D018450:Disease Progression; D066255:EGF Family of Proteins; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D015151:Immunoblotting; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D053208:Kaplan-Meier Estimate; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D008875:Middle Aged; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous; D000099162:Endothelial PAS Domain-Containing Protein 1
D066258:Amphiregulin; D051792:Basic Helix-Loop-Helix Proteins; D066255:EGF Family of Proteins; D006023:Glycoproteins; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D036341:Intercellular Signaling Peptides and Proteins; D011393:Procollagen-Proline Dioxygenase; D000099162:Endothelial PAS Domain-Containing Protein 1; C587848:AREG protein, human; C587849:Areg protein, mouse; C490190:EGLN1 protein, human