The Correlative Study Between The Expression And Role Of Platelet-derived Endothelial Cell Growth Factor / Thymidine Phosphorylase And Cyclooxygenase-2 In Gastric Carcinoma

BackgroundGastric carcinogenesis is a process associated with many genes and factors. Modern molecular biology indicated that it is a multiple procedure from normal epithelia cells to clinical tumor cells which associated with the accumulation of multiple gene abnormal .The development and progression of gastric cancer were correlated with oncogenes , growth factors, cyclins, tumor suppressorgenes, cell adhesion molecules and unstability of genes, etc. However, neoplastic proliferation and apoptosis are the essential process. The tumor angiogenesis play an important role in the procedure of proliferation and metastasis in gastric cancer, which provide the way to tumor growth and dissemination. PD-ECGF was a comparatively new factor in angiogenesis investigation domain, which play an important role in the process of proliferation, differentiation, metastasis and apoptosis in gastric cancer. COX-2 facilitated tumor proliferation and decreased tumor apoptosis. However , few investigation has been taken between the relationship between PD-ECGF and COX-2. The purpose of this study was to explore the mechanism of the gastric carcinogenesis in molecular biology level by invested the expression of PD-ECGF and COX-2 , the relationship between them and the influence on MVD and AI, thus providing a theoretical basis for diagnosis and therapy of gastric cancer.Objective1. To study the expression of PD-ECGF and COX-2 and the action in the process of proliferation and metastasis in gastric cancer as well as therelationship between PD-ECGF and COX-2 and clinicopathological factors such as sex, histological type, histology and lymph node metastasis.2. To elucidate the relationship between PD-ECGF and COX-2 in gastric cancer.3. To explore the influence on MVD and AI by PD-ECGF and COX-2 in gastric cancer and the relationship among them.Materials and Methods1, 67 gastric biopsy specimens ,each with adjacent mucosa were obtAIned fromupper gastrointestinal endoscopy or surgery operation, with 30 chronicsuperficial gastritis (CSG) as control. All subjects were diagnosed withhistopathology.2. The mRNA expression levels of PD-ECGF and COX-2 were assessed bysemi-quantity RT-PCR ; The protein expression rates of PD-ECGF and COX-2were determined by immunohistochemistry (SP) in gastric cancer tissues,adjacent mucosa and chronic superficial gastritis.3. VIII factor was used to study the microvascular density (MVD) level byimmunohistochemical staining (SP) in gastric cancer tissues.4. Apoptosis index(AI, percentage of apoptosis cells) in gastric carcinoma wasexamined by flow cytometry.Result1. Expression of PD-ECGF and COX-2The positive protein expression rates of PD-ECGF was 52.2% ( 35/67 ) and COX-2 was 65.7%(44/67) in 67 gastric cancer tissues; The positive expression rates of PD-ECGF was 13.4%( 9/67 )and COX-2 was 20.9 %(14/67) in adjacent mucosa; The positive expression rates of PD-ECGF was 6.7 % ( 2/30) and COX-2 was 10%(3/30) in chronic superficial gastritis tested by immunohistochemistry (SP). There was a close correction between mRNA andprotein level of PD-ECGF (r2 = 0.830,P<0.01 ) ; There was also a close relationship between mRNA and protein level of COX-2 ( r2 = 0.793, P<0. 01 ) , indicating the coincidence of the two detected result. The positive expression rates of PD-ECGF and COX-2 in gastric cancer tissues was significantly higher than that in adjacent mucosa and chronic superficial gastritis tested by immunohistochemistry (SP) and RT-PCR method. 2. Expression of MVD and AIThe positive protein expression rates of MVD was significantly higher in 67 gastric cancer tissues than that in adjacent mucosa and chronic superficial gastritis tested by immunohistochemistry (SP)(p<0.05). AI in gastric cancer tissues was significantly lower than that in adjacent mucosa and chronic superficial gastritis(p<0.05).3. The relationship among the expression of PD-ECGF,COX-2,MVD, AI and clinicopathological factors67 gastr...