The Expression And Clinical Significance Of FGFR2, VEGFR2 And C-Cbl In Gastric Carcinoma

IntroductionGastric carcinoma is the most common gastrointestinal carcinoma among the world. The incidence of gastric cancer lies in the fourth place of all malignant tumors, and it is also the second largest cause of death among all kinds of cancers. The long-time application including excision and the other combined therapy doesn't result in satisfactory survival rate. Up to now gastric carcinoma is still one of the main causes of death and it is extremely serious in China and the other eastern Asian counties.Following the deep investigation and study of oncomolecularbiology, a new drug treatment is developed as molecular targeting therapy. Targeted therapeutic agent gets more and more attention because of its features of being high performance and low poisonous. So far molecular targeting therapy is focused on signal conducting pathway related to cell growth, differentiation and apoptosis regulation mechanism which is regulated by the activation of some tyrosine kinases.Fibroblast growth factor receptor-2 (FGFR2) and vascular endothelial growth factor receptor-2 (VEGFR2) are both RTK and there are researches indicating FGFR2 and VEGFR2 play a very important role in form of tumor vessel and have a very close correlation with the staging, metastasis, prognosis and curative effect so that they are important to molecular targeting therapy. c-Cbl is recently proved to be a new ring finger type ubiquitin ligase, E3 in ubiquitin-proteasome pathway, UPP. c-Cbl can mediate degradation of RTK and nonreceptor tyrosine kinase so that it can take part in negative regulation mechanism of the signal conducting in the cells.There are few researches concerned about the expression and association of FGFR2, VEGFR2 and c-Cbl. This study focuses on analyzing the relationship between their expressions and clinicopathologic parameters and the association among the three investigated objects and further approaching the expression and clinical significance of FGFR2, VEGFR2 and c-Cbl in gastric cancer by constructing tissue microarray of gastric cancer and detecting the expressions of these three proteins with immunohistochemical method.Materials and Methods1. Patients124 gastric cancer cases underwent completely resected operation, which were enrolled from the first affiliated hospital of China Medical University (CMU) and Liaoning Cancer Hospital, and none of them underwent chemotherapy and radiotherapy before operation. There were 92 male and 32 female patients with median age of 60 years. The histologic type of all cases is adencarcinoma with 11 cases of well differentiation (8.9%),29 moderated differentiation(23.4%)and 84 poor differentiation(67.7%).There were 76 cases with muscular layer invasion(61.3%)and 48 placenta percreta invasion (38.7%) . There were 100 cases with lymph node metastasis (80.6%).There were 17 cases in stage I (13.7%),46 in stage II (37.1%),37 in stage III (29.8%)and 24 in stage IV(19.4%).24 normal tissue cases were selected as controls, which were at least 5 centimeters far from gastric cancer tissues.2. MaterialsAntidodies for immunohistochemistry: The polyclonal rabbit anti-human antibody against FGFR2 was purchased from ABCAM corporation;The polyclonal rabbit anti-human antibody against VEGFR2 was purchased from Fuzhou Maixin Biotechnology;The monoclonal mouse anti-human antibody against c-Cbl was purchased from BD corporation, Inc.;S-P immunohistochemical kits and DAB substrate solution were purchased from Fuzhou Maixin Biotechnology, Inc.3. MethodsImmunohistochemical staining S-P method was performed on tissue microarray sections made of 124 cases of gastric carcinoma and 24 normal tissue cases . Slides of FGFR2, VEGFR2 were treated with citric acid buffer (PH=6.0) to recover the antigen ctivity in microwave oven, c-Cbl needn't recover the antigen. Tissue chip was made in Shanghai supercore Biotechnology, Inc.4. Assessment Outcome definition of FGFR2, VEGFR2 and c-Cbl were stained yellow particles in membrane and cytosol. Judging reference considered the scores of both proportion and intension of positive stained. (-)was negative stained, (+)was defined as weekly positive,(++)-(+++)was defined as strongly positive.5. Statistical analysisStatistical methods Chi-square test,Fisher exact test,Mann-Whitney U test and Spearman rank correlation test were performed by SPSS software version 13.0. The statistical difference was considered significant when P<0.05.Results1. The expression of FGFR2,VEGFR2 and c-Cbl in patients with gastric cancerThe positive expression rate of FGFR2, VEGFR2 and c-Cbl were 77.4%,85.5% ,71.0%. They were all highly expressed in gastric carcinoma.2. The relationship between expression of FGFR2, VEGFR2 and c-Cbl and clinicopathologic parameters in patients with gastric cancerThe expression of FGFR2 was positively correlated with depth of invasion (r=0.264,P=0.003) and TNM staging(r=0.260,P=0.004).The expression of VEGFR2 was positively correlated with depth of invasion (r=0.311,P=0.000) and lymph node metastasis (r=0.451,P=0.000) and TNM staging(r=0.554,P=0.000).The expression of c-Cbl was positively correlated with depth of invasion (r=0.219,P=0.015) and TNM staging(r=0.266,P=0.003).3. The relationship between FGFR2, VEGFR2 and c-CblThere was a positive relationship between the expression of FGFR2 and c-Cbl (r=0.465,P=0.000); there was also a positive relationship between the expression of VEGFR2 and c-Cbl (r=0.190,P=0.035).4. The relationship between synchronous strongly positive expression of the three proteins and clinicopathologic parameters in patients with gastric cancerSynchronous strongly positive expression of FGFR2, VEGFR2 and c-Cbl was observed in 26 cases. Among 26 cases with simultaneous strongly positive expression of FGFR2, VEGFR2 and c-Cbl most were found in poorly differentiation, deep invasion, lymph nodal metastasis and advanced cases.Conclusion1. The positive expression levels of FGFR2, VEGFR2 and c-Cbl in gastric cancer tissue were higher than those in normal tissues. The positive expressions of FGFR2 and c-Cbl are associated with deep invasion and late TNM stage, and VEGFR2 is associated with deep invasion and lymph nodal metastasis late and TNM stage, meanwhile synchronous strongly positive expression of FGFR2, VEGFR2 and c-Cbl are more often found in poorly differentiation, deep invasion, nodal metastasis and advanced cases.2. There was a positive relationship between the expression of FGFR2 and c-Cbl, there was also a positive relationship between the expression of VEGFR2 and c-Cbl.