The Significance Of VEGF Levels In Plasma And Urine Of Glioma Patients In Pre-Operation And Post-Operation

Objective: Angiogenesis of tumor is the base of tumor growth and invasion. Vascular endothelial growth factor (VEGF) is the most potent angiogenesis factor and has been detected in many human tumours. VEGF has been reported to relate closely to tumour progression and metastasis. The purpose of our study was to determine the plasma and urine VEGF levels in normal controls and patients with glioma and elucidate their significence of pre-operative and post-operative levels.Methods: VEGF levels were examined in plasma and urine samples using enzyme-linked immunosorbent assay(ELISA) kits with antibodies which recognize human VEGF₁₆₅. Plasma and urine samples were obtained from 12 normal controls and 37 pre- operation and post-operation glioma patients(6 grade â…  ,10 grade â…¡ , 9 grade â…¢,12 grade â…£). For plasma collection, blood samples were drawn into vacutainer tubes containing 10% sodium ethylene- diamine tetra-aceteic acid (EDTA-Na); For Urine collection, urine sampleswere drawn into plastic test tubes, the collected samples were immediately prepared by centrifugation at 5,000 rpm and stored the upper liquid at -70°C until the day they were assayed. The amount of VEGF detected in each samples with CytElisa? Human VEGF kit is compared to VEGF standard curve which demonstrates the relationship betweet Optical Density(O.D.) and VEGF concentration. The numerical value of VEGF were recorded in terms of meant standard deviation. Statistical analysis was performed with the SAS version8.0 software application, using t-test,analysis of variance and Spearman rank correlation analysis. P value less than 0.05 were considered statistically significant.Results: VEGF levels of 12 normal healthy controls and 37 patients with glioma in pre-operation and post-operation were compared. VEGF was detected of healthy controls with a mean value of 56.97+ 13.83pg/ml in plasma, 103.82+ 11.36pg/ml in urine which respectively were statistically significantly different from the VEGF levels in the pre-operative glioma patients. In the pre-operative urine of patients with glioma with a mean value of 127.32± 4.67pg/ml in grade,193.82 + 28.75pg/ml in grade II ,438.47+ 43.48pg/m in grade III, 632.92 + 59.74pg/ml in gradelV. There is a positive correlation relationship between VEGF levels in urine of glioma patients in pre-operation and pathological grading of glioma through Spearman rank correlation analysis. The plasma VEGF levels in the total cut-off group(30 patients) were detected with a mean value of 140.68 + 79.90pg/ml in pre- operative which were significantly higher than those detected with a mean value of 77.29 + 31.67 pg/ml in post-operation. Otherwise, there were no statistically significantly different between pre-operative(l 78.96 + 94.71pg/ml)and postoperative (166.1 + 83.70pg/ml) in partial cut-off group(7patients).Conclusions: Between VEGF levels of normal healthy people in plasma and urine and those of patients with glioma in pre-operation were statistically significant. VEGF levels in urine had an important significance to evaluate the malignant biological behavior of glioma, and therefore can serve as a biological marker for glioma grading. VEGF levels in plasma and urine had an practical vaule in pre-operation and post-operation to judge the extent of glioma excision.