| Astrocytic tumors,the most common tumors in the central nervous system,are characterized by active angiogenesis,in which vascular endothelial growth factor(VEGF) plays a prominent role.VEGF promotes proliferation,differentiation and remodeling of blood vessel endothelial cells by binding to its receptors.The parameters,such as VEGF expression intensity,microvessel density(MVD),can be used to assess the malignancies, predict the prognoses of astrocytomas.Detection of the expression of VEGF helps to understand the mechanism of angiogenesis in tumor.Tumor microvascular architecture phenotype(T-MAP),reflecting the density,morphology,structure and the threedimensional distribution of newly formed vessels can be demonstrated by histology and immunohistochemistry.The diversity of T-MAP is called T-MAP heterogeneity(T-MAPH). Tissue chip,or called as tissue microarray,referenced to the way of making gene chip and protein chip,integrates more than thousands of different samples on one solid phase supporter to form a tissue chip.Tissue chip favors high effective detection of large samples simultaneously.It can be applied to study the correlation between specific gene,or their proteins and lesion or normal tissues.T-MAPH includes 3D distribution of blood vessel.The distribution can not be directly observed under light microscope.One acceptable solution is serial tissue section and staining followed by computer-aided 3D reconstruction through which the 3D distribution of microvessel can be observed and some parameters easily measued.And these results can help to understand the significance of T-MAPH.In this study,double immunohistochemical technology and image analysis were used to obtain microvessel density,average perimeter of microvessel and VEGF positive unit and performe quantitative analysis on astocytoma tissue chip.Then typical astracytomas were selected to reconstruct microvessels by serial section(total thickness 320μm),and 3D technology.Data were processed by SPSS13.0 and MATLAB7.1.The main results and conclusions are as follows:1.Image analysis and statistical analysis on human astrocytoma tissue chip showed that VEGF PU value and blood vessel number was increased with the grade of tumors, whereas the trend of mean perimeter was contrary.2.Expression and distribution of VEGF in astrocytoma had different patterns,which had mathematical relation with microvessel distribution.The mathematical equation was: y=1/(45.1+6.06x)1/2(R=0.6124,p＜0.01).3.Reconstruction of the 3D distribution of CD34 positive cell in astrocytoma was conducted by quantitative immunohistochemistry and computer assisted programs.Significance of this study:The distribution of VEGF is the foundation to study the possible mechanism of tumour microvessel architecture phenoype presence heterogeneity.It is a series of measuring means to build up homologus tumour microvessel tissue microarray,multiple-label immunohistochemistry for VEGF and blood vessel endothelia,and obtain parameters of blood vessel and VEGF distribution.The microvessel architecture parameters,VEGF expression data and the distribution character obtained from tissue chip in this study will contribute to our better understanding of T-MAPH,and will set a solid foundation to construction of digitalized tumour microvessel architecture,assessment of microvessel and angiogenesis factor mathematical models.
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