Research Of The Expression Of CRFR2 In The Tumor Of The Central Nervous System

CRF is an important hypothalamic neuropeptide, and distributed in the hypothalamus, which mainly regulates the hypothalamus-pituitary-adrenal (HPA) axis fuction when the body is under stress, coodinates the endocrine system, the autonomic nervous system and immune system function under stress. CRF is also widely distributed in peripheral tissues, and has a moderating effect on cardiovascular, gastrointestinal, reproductive, skin, etc…CRF has two receptors: CRFR1 and CRFR2, which have physiological activity, it play its effect through the combination with its receptor. CRFR2 is an important receptor of CRF. Existing research and literature reported that expression of CRF and CRFR2 have also been found in some types of human malignancies, and in some animal models it has been confirmed that the CRFR2 related to tumor proliferation, metastasis, angiogenesis and immune evasion, etc. so far, at home and abroad, there has yet no report on the expression of CRFR2 in neuroepithelial tumors in the central nervous system.Purpose: To investigate the expression of corticotropin releasing factor receptor 2(CRFR2) in the glioma and pituitary tumors in the central nervous system, and in human U87 glioma cells.Methods: Surgical biopsy specimens of some types of tumors which had definite pathological diagnosis, 30 casses of glioma, 10 cases of pituitary adenoma, which were randomly collected, and cultured human glioblastoma cell line U87. we applied CRFR2 antibody to the tissue samples collected and cells cultured in Immunohistochemical staining and then analyze the results. The total RNA were extracted from U87 cells cultured, and designed the primer of CRFR2mRNA for the RT-PCR experiments, amplified products were made for agarose gel electrophoesis, and analyze the expression of CRFR2 mRNA in the cultured cells.We analyzed for linear correlation between CRFR2 and tumor marker respectively by medical statistical software SPSS13.0, further, which include MGMT,GFPA,P53,MMP-9 and the pathological grade of glioma, analyzed the relation between the expression of CRFR2 and glioma.Result: CRFR2-positive samples can be seen in the tumor cells, Immunohistochemical staining parts located in the cells'membrane area and presented a clear yellow or brown. many of which had larger size, round and large nuclei or fission and a larger karyoplasmic ratio, and some stained slightly stronger presented brown, some stained weaker presented light yellow, the distribution of staining was scattered or flake. The majority of mesenchymal tissue cells were negative, and in some cases the expression of positive immunohistochemistry in vascular endothelial cells and necrosis were also positive. In different cases, large differences in the percentage of positive cells about from 5% to 90%. 10 cases of pituitary adenoma all expressed as positive, including 5 cases of PRL adenoma which was moderately positive to strong positive, 1case of TSH adenoma expressed as strong positive, 1 case of ACTH adenoma expressed weakly positive, and 3 cases of GH adnoma expressed weakly positive to moderately positive. In the 30 cases of glioma, there were 16 cases of astrocytoma, CRFR2-positive samples were 5 cases, accounted on the proportion of 31.25% in the astrocytoma cases(5/16). In these cases, the pathologic level of gradeⅡ6 cases, gradeⅡ-Ⅲ2cases, had no positive expression of CRFR2; there were 6 cases of gradeⅢ, 2 cases were negative, 2 weakly positive, 1 moderately positive, 1 strong positive, 1 case expressed as moderately positive in 2 cases of gradeⅣ, included respectively; 1 of 3 multiforme glioblastoma tumor cases whose pathological grade level areⅣexpressed as strong positive, 2 expressed as negtive; The expression of CRFR2 in 2 ependymoma cases was negative, and the pathological levelⅡandⅢ1 case included respectively; 1 case of medulloblastoma had no expression of CRFR2 whose pathological level wasⅣ; Immunohistochemical analysis showed that U87 glioblastoma cells expressed CRFR2 as negative, the amplified products of RT-PCR were made for gel electrophoresis which showed no bands, the results showed that there was no expression of CRFR2 in U87 cells cultured. The results of linear correlation between CRFR2 and MGMT, GFPA, P53, MMP and the pathological grade of glioma showed the"rs": 0.157,-0.150,0.157,0.248,0.363, respectively; and the"P": 0.408,0.430,0.408,0.185,0.049. In the result of linear correlation between CRFR2 and tumor grade,"rs"was 0.363, 0<0.363<1, and the"P"was 0.049, P=0.049 < a=0.05, but the other 4"P"were all more than 0.05.Conclusion: The above types of neural tumors investigated showed that all the types of pituitary adenoma such as Prolactinomas, TSH adenoma, GH adenoma and ACTH adenoma were in positive expression of CRFR2 in deferent degree. In human glioblastoma cell line U87 CRFR2 is expressed as nagtive. Part of astrocytoma and multiforme glioblastoma tumors had the positive expression of CRFR2 in deferent degree while negative expression in small branch glioblastoma and medulloblastoma and ependymoma. Statistical result suggest that the linear correlation relation between CRFR2 and MGMT,GFAP,P53,and MMP-9 respectively had no statistical significance; However, the linear correlation relation between CRFR2 and tumor grade is positive, in the words, the expression of CRFR2 in glioma increased with the increasing of the pathological grade of glioma, analysis showed that the expression of CRFR2 in gliomas had statistical and clinical significance.