Immunohistochemical localization of thymidine phosphorylase in gastric cancer: is there a role of the differential expression in tumor cells and associated stromal cells?
BACKGROUND
The aim of this study was to investigate the expression of thymidine phosphorylase (TP), a known angiogenic factor for endothelial cells, in gastric carcinoma cells and tumor-associated stromal cells.


METHODS
Sixty-six gastric carcinomas were studied. TP expression was assessed with the P-GF.44C mouse monoclonal antibody using the avidin-biotin immunoperoxidase technique. The results were correlated with several clinicopathological parameters and patient survival.


RESULTS
TP expression in cancer cells was related to the age of the patients and the overall survival. When TP was expressed in tumor-associated stromal cells, it was statistically related to poorly-differentiated tumors. Statistical analysis revealed no relationship between TP expression and any of the clinicopathological parameters under evaluation, when considering stromal TP immunoreactivity separately for stromal fibroblasts and associated inflammatory cells, or when considering the tumors as TP-positive, irrespective of the tissue localization of the enzyme.


CONCLUSIONS
TP seems to be a prognostic indicator in gastric cancer patients only when the enzyme is located in tumor cells. The different impacts of TP expression in tumor cells and associated stromal cells might indicate that the enzyme may have more than one function involved in tumor growth.
Liakakos
Theodore
T
Third Department of Surgery, University of Athens, ATTIKON, University General Hospital, 1 Rimini St., Haidari, 12462 Athens, Greece.
Troupis
Theodore
T
Ghiconti
Ioanna
I
Triantafyllidis
Spyros
S
Macheras
Anastasios
A
Karatzas
Gabriel
G
Pavlakis
Kitty
K
D006801:Humans; D007150:Immunohistochemistry; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology; D017154:Stromal Cells / Q000201:enzymology*; D013939:Thymidine Phosphorylase / Q000037:antagonists & inhibitors*
D013939:Thymidine Phosphorylase