Expression Of Thymidine Phosphorylase/platelet-derived Endothelial Cell Growth Factor In Gastric Carcinoma And Precancerous Lesions

Gastric carcinoma is a common tumor in digestive system. Although great progress has been made in this area, prognosis of gastric carcinoma is still poor because of absence of effective prevention measures. Numerous studies have demonstrated that the growth and metastasis of malignant tumors are dependent on neovascularization in tumors which is associated with angiogenic factors including PD-ECGF (Platelet-derived endothelial cell growth factor) and VEGF (Vascular endothelial growth factor). PD-ECGF has been found to be identical to thymidine phosphorylase (TP) , TP/PD-ECGF derives from platelet which maintains the stability of blood vessel endothelial cells. The level of TP/PD-ECGF expression is high in many tumors and significantly correlated with the microvessel density (MVD)in tumors. TP/PD-ECGF facilitates to angiogenesis and may be involved in the growth metastasis and recrudesce of solid tumors. Intestinal-type gastric carcinoma is derived from precancerous lesions, such as chronic atrophic gastritis intestinal metaplasia and dysplasia. However, it is still unknown if TP/PD-ECGF isexpressed in precancerous lesions. Can we prevent gastric carcinoma through inhibition of TP/PD-ECGF expression and angiogenesis? So far there's few research accomplished in precancerous lesions and TP/PD-ECGF. Our work just want to find the difference of TP/PD-ECGF, MVD and platelet number between gastric carcinoma and precancerous lesions in order to make a progress in gastric carcinoma precautions.Materials and methodsSpecimen117 pathological slices of gastric tissue specimens and corresponding platelet count data were obtained from the Second Hospital of Jiaxing from June 2003 to December 2005. Endoscopic specimens include 12 normal gastric mucosa;43 gastric mucosa with intestinal metaplasia and 35 dysplastic gastric mucosa, 27 postoperative gastric carcinoma samples were also obtained from the hospital.MethodsExamination and judgement of CD34 and TP/PD-ECGFImmunohistochemistryMouse anti-human TP/PDECGF monoclonal antibody and Mouse anti-human CD34 monoclonal antibody were obtained from Maixin-Bio company of Fuzhou, SP reagent box was bought from Beijing Zhongshan Biotechnology Co. Ltd. PBS solution is used as negative control. Intensity of cell stain and area of stain cells were the main indexes in TP/PD-ECGF. The stained section were screened at X 5 magnification under a light microscope to identify the three regions of the section with the highest number of microvessels. Microvessels were counted in these area at X400 mannification (X40 objective lens and X10 ocular lens),and the averagenumber of micro vessels were recorded.Platelet count in bloodThe count of platelet is measured by Advia 120 Hematology System, Bayer Company, Germany.Statistical AnalysisThe statistical analysis is depended on SPSS for Windows 12.0, all of the data are analysed by t-tesU Ar^-test and Spearman rank correlated analysis.ResultsThe expression of TP/PD-ECGF in various groupsThe positive ratio of TP/PD-ECGF in normal stomach tissue is about 25% whereas intestinal metaplasia and dysplasia are 34.88% and 65.71% respectively. Intestinal-type gastric carcinoma is 92.95%, which is the highest in 4 groups.Pearson x-2-test indicate notable difference among all 4 groups.The relation between MVD and TP/PD-ECGFMVD is significantly different in TP/PD-ECGF positive and negative groups of all 117 patients (/=4.337, /7=0.000) .The MVD of dysplasia is also significantly different in TP/PD-ECGF positive and negative groups (/=2.469, />=0.019) .The meanof MVD show notable difference among all groups except intestinal metaplasia group and dysplasia group.The mean of MVD and platelet count rise gradually in 4 groups. Otherwise, platelet count is significantly different in normal gastric tissue group g and gastric carcinoma group.ConclusionsAs a result there is more TP/PD-ECGF expression and MVD in gastric carcinoma precancerous lesions and gastric carcinoma. The MVD is increased by the expression of TP/PD-ECGF. It is suggested that the platelet may contribute to gastric carcinoma progression since the platelet count of gastric carcinoma group is higher than normal gastric tissue group.