| IntroductionAngiogenesis is an essential factor for development and metastasis in solid tumors. Vascular endothelial growth factor ( VEGF) secreted from tumour cells plays a crucial role in the regulation of angiogenesis in tumour tissue. VEGF is a specific mitogen of endothelial cells and also the only factor which can increase vascular permeability. It can affect every step of neovascularization directly and indirectly. During the process of tumour growth , tumour cells secret lots of VEGF, and then VEGF combines with its receptor on near host vessel and induces the endothelial cells to compound many proteolysis, which can destroy the basal membrane of host vessel and abate its protective function. In addition, VEGF increases vascular permeability and promote blood plasma including fibrinogen to infiltrate and form the new matrix for the necessary of endothelial cells coherence and migration. At the same time, endothelial cells increase and migrate under the stimulation of VEGF. Through the basal membrane of original vessel, along the new extracellular matrix, they migrate to the stimulator, extending into tumour tissue, crisscross anastomosising and form a vascular web to supply blood for tumor. On one hand, the abundant neovascular net can transport oxygen and nutrition , convey metabolite and satisfy the need of tumour development; on the other hand, increasing of vascular permeability and incompletion of neovascular basal membrane offerthe convenient condition for tumour infiltration and metastasis.These years, lung cancer has becoming a world problem. Infiltration and metastasis are the main mortal reasons of lung cancer. We examined the protein expression of VEGF in Non - Small cell lung career ( NSCLC) and the adjacent normal tissues by using the immu-nohistochemistry and Western Blotting method to find out the relation of VEGF expression to histological type, pathological stage, lymph node metastasis and survival time and supply some significant evidence for studying pathogenesis, directing clinical therapy and improving survival time.Materials and methodsAll the 49 NSCLC cases with their adjacent noncancerous tissues used in immunohistochemical study were obtained from Liaoning Tumor Hospital from Novmber, 1999 to February ,2000. Follow - up lasted until March, 2002. The other 20 NSCLC samples used in Western Blotting were obtained from the First Affiliated Hospital of China Medical University from March to June, 2001. They were analyzed by immunohistochemistry S - P method at the same time. Immunohistochemical evaluation was performed by a pathologist in a blind test. At least 10 high - power fields from a single tissue section were chosen at random, and 1000 tumor cells were counted. Positive cells were stained dark brown on the cytoplasm. The intensive score was categorized into the following 3 groups: 0, no staining; 1, mild staining; 2, marked staining. The sum score of positive cell was classified into 4 groups.- 0, less than 10% positive; 1, more than 10% but less than 40% positive; 2, more than 40% but less than 70% positive; 3,more than 70% positive. The product of intensity score and sum score was classified as following 3 grades: negative, product score was 0; mild positive, product score was 1 - 3; marked positive, product score was more than 4. Positive result of Western Blotting was presenting a characteristic band corresponding to VEGF protein. All statistical analyses were conducted by SPSS for windows 10. 0 statistical software system. Survival curves were calculated using the method of Kaplan - Meier and tested by the Log - rank test. The influence of each variables on survival was assessed by the Cox modle. A significant difference was identified when the probability was less than 0.05.ResultVEGF immunoreactivty was mainly located in the cytoplasm of neoplastic cell. 43 of 69 tumor samples showed VEGF immunoreactivty, and the adjacent normal lung tissues occasionally presented a weakly VEGF positive (5/69) , being of significant difference. The frequenc...
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