Expression Of UPA,uPAR And PAI-1 In Nephroblastoma And Its Signification

Background and ObjectiveNephroblastoma, or named embryonic tumor of kidney, is one of the most common pediatric abdominal malignant tumors in children. It consists of 97% in all renal tumors. In 1899, Max Wilms described its characteristics, so it was named after his name. Nephroblastoma is malignant mixed tumor, derived from embryonic renal tissue. It always occurred local spread, lymphatic metastasis and hematogeneous metastasis in 6 mouths to 3 years. At present, it is considered that nephroblastoma was a curable disease, and its prognosis was better than other malignant tumors, although it was malignant. Histological type and clinical stage are important criteria in instituting heal project and prediction of outcome. An independent prognostic molecular marker has not been identified as yet. Anaplasia type has been proven to be of prognostic value and is associated with poor prognosis.Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and plasminogen activator inhibitor- 1(PAI-1) are part of the urokinase-type plasminogen activator system, playing an important role in degrading extracellular matrix and dissolution of the basement membrane. These proteins regulate together infiltration of tumor cell, angiogenesis and metastasis. Via studying theirexpressions in nephroblastoma, we will provide a possible way in its biological therapy. There was no report about these proteins' expression in nephroblastoma in our internal periodical. The purpose of this text is to study the proteins' value of occurrence, development, clinical diagnosis and forecasting prognosis in nephroblastoma, and provide a new direction of full of foreground for gene therapy of nephroblastoma.In this research, the expression of uPA, uPAR and PAI-1 proteins was detected by the immunohistochemistory SABC method in 30 nephroblastoma specimens (tumor group) and 15 non-neoplasia renal tissue specimens (control group), and all the sections were formalin-fixed and paraffin-enbeded. The purpose of this research is to study expressions of three proteins and relations with histological types and clinical stages and to find out those proteins' roles in tumor's local spread, metastasis, angiogenesis and prognosis.Materials and MethodsThirty nephroblastoma specimens had been collected from surgical resections. These patients, from 7 months to 9 years, average 2.6 years, 19 males and 11 females, were not performed any radiotherapy and chemotherapy. By NWTS-5 criteria, histological types of their HE staining sections were classified by two types. Among them 23 patients belonged to favorable histology (FH) type, and 7 patients did unfavorable histology (UH) type. Clinical stages were classified by two types. Among them 13 patients belonged to low clinical stage, and 17 patients did high clinical stage. Control group, 15 patients, consisted of 6 normal renal tissues near tumor and 9 non-neoplasia renal tissues. Every specimen had been stained in HE staining and immunohistochemistory. Expression of uPA, uPAR and PAI-1 patients was detected by SABC method. The results were analyzed by SPSS 10.0 statistical software. Data were presented as mean ?SEM. Statistical analysis was done by Pearson's chi-square test, Fisher's exact test or Student's t test. The relationships between expression of uPA, uPAR, and PAI-1 were evaluated by the linear correlation test. =0.05 were considered significant test level.Results1. The positive rate of uPA in nephroblastoma group was 66.7% (20/30), but in control group the positive rate was only 6.7%(1/15). There was significant difference (P <0.05). In control group, a part of renal tubules had weak staining and a few of vessel endotheliocytes showed a very intense staining. Significant correlateions were caught between expression and histological type or beteeen eppression and clinical stage. There were significant difference among them(P <0.05). In UH type and in high clinical stage the expression was stronger than in FH type and in low clinical stage.2. The positive rate of uPAR in nephroblasto...