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Platelet‐derived endothelial cell growth factor/thymidine phosphorylase expression in normal tissues: An immunohistochemical study
Author(s) -
Fox Stephen B.,
Moghaddam Amir,
Westwood Mark,
Turley Helen,
Bicknell Roy,
Gatter Kevin C.,
Harris Adrian L.
Publication year - 1995
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1711760212
Subject(s) - thymidine phosphorylase , biology , angiogenesis , stromal cell , cytoplasm , immunohistochemistry , thymidine , growth factor , endothelial stem cell , microbiology and biotechnology , immunology , in vitro , cancer research , biochemistry , receptor , enzyme
Angiogenesis is the formation of new blood vessels from the existing vascular bed. It is a complex multi‐step process controlled by a number of angiogenic factors. One such factor is platelet‐derived endothelial cell growth factor (PD‐ECGF), recently shown to be thymidine phosphorylase (TP), which is angiogenic in several in vivo assays and tumour systems. PD‐ECGF/TP catalyes the reversible phosphorylation of thymidine to deoxyribose‐1‐ phosphate and thymine. Since PD‐ECGF/TP has an important role in cellular metabolism and in angiogenesis and its expression has been only partially characterized, we raised a monoclonal antibody against recombinant PD‐ECGF/TP and used an immunohistochemical approach to examine the expression of PD‐ECGF/TP in a comprehensive range of normal human tissues. The clone P‐GF44. C, which recognized recombinant PD‐ECGF‐TP and cell lysates transfected with a plasmid expressing PD‐ECGF/TP cDNA on Western blotting, was selected for its ability to stain routinely processed tissue. Staining was observed in both the cytoplasm and/or the nucleus. Immunoreactivity was strongly expressed by macrophages, stromal cells, glial cells, and some epithelia. Gastrointestinal epithelium, smooth muscle, adrenal, lung, and testis were negative. Although endothelial cell expression was observed, there was no correlation with sites of new vessel growth. This pattern of expression suggests tight PD‐ECGF/TP regulation and that cellular thymidine pools may serve to control its different functions. Thus, in the nucleus it might modulate the pool for DNA synthesis, whilst in the cytoplasm it could control other effects through different enzyme systems. The high expression present in macrophages and skin might be important for total body thymidine homeostasis.