The Abnomal Expression Of Cell Cycle Regulatory Gene In Brain Glioma

Objective: In the final analysis,the growth of tumor is out of control because of the uncontrolled proliferation of tumor cells. However,the uncontrolled proliferation of tumor cells due to the destruction of precise cell cycle control mechanism. The run of cell cycle control mechanism depend on the precise ,complex ,ordinal activation of a series of protein kinases. It is the precision that any minute destruction can make it abmormal,arrest or uncontrol ,cause cell to death or tumor.It is the complexity that each cell cycle fator keep its mystery.Brain glioma is one of the most common tumor of central nervous system,and the pathogenesis of which is not yet completely clarified. In this report, CyclinD1,CyclinE as two cell cycle rate-limiting step fators and their inhibitive fator p21,p27 and the fator related to cellproliferation PCNA were detected in order to further investigate the abnormality of cell cycle control mechanism's effect on the genesis,development and prognosis,and expect for providing possible means and methods.Materials and Methods: 50 patients with glioma who underwent operation at the Second Affiliated Hospital,Hebei Medical University from 2001 to 2002 were collected,and which included 31 cases of Male and 19 cases of Female.The range of age was from 14 years old to 76 years old,and include 14 cases of <30 years old,28 cases of 30-60 years old and 8 cases of >0 years old.The range of disease course was from 1 week to 6 months.Preoperative chemiotherapy, radiotherapy and immunosuppressive therapy were not performed to all of the patients.Routinely processed 4% formamint-fixed.Each specimen split into two pieces:one for flow cytometry,the other for immunohistochemistry staining. Serial sections of 5μm were cut from the blocks,Then representative sections were stained with H&E in order to comfirm the histopathological diagnosis.The tumors were graded and classified according to the WHO(1999) scheme and consisted of 9 cases of WHO grade Ⅰ[pilocytic astrocytoma(7), choroid plexus papilloma (2)],22 cases of WHO grade Ⅱ[fibrillary astrocytoma(13),protoplasmic astrocytoma (4), oligodendroglioma (4), and ependymoma (1)],9 cases of WHO grade Ⅲ[anaplastic astrocytoma(8),and ependymoma(1)], and 10 cases of WHO grade Ⅳ[glioblastoma multiforme (6), ependymoblastoma(2), and medulloblastoma(2)].5 cases of normal brain tissue used as control groups were obtained from the patients with brain trauma who underwent inter-decompression.46 cases(92%) of all patients were followed up in a year, which consisted of 16 cases (34.8%) of death,30 cases (65.2%) of survival.Immunohistochemical stains(SP) were performed to examine the expression of CyclinD1,CyclinE, p21,p27 and PCNA. The nuclear of PCNA positive cells showed buffy staining. Scoring the percentage of labeled cells in at least five high-power fields(×400) and counting 200 tumor cells every fields,PCNA took it as Proliferative index(PI). Assessment of CyclinD1,CyclinE, p21,p27 expression was based on the mean percentage of positive tumour cells in at least five high-power fields(×400) assigned to one of five categories:0:no positive tumor cell;1:the percentage of positive tumor cells <25%；2:percentage of positive tumor cells 25%～50%；3:percentage of positive tumor cells 51%～75%;4:percentage of positive tumor cells>75%. Flow cytometry(FCM)were performed to examine the expression of CyclinD1,CyclinE, p21,p27.Assessment of CyclinD1,CyclinE, p21,p27 expression was refer to Fluorescent index(FI) suggesting by Morkve. The software package SPSS 11.5 was used for statistical analysis.Proliferative index(PI) and Fluorescent index(FI) are reported as mean±standard deviation.The X2 test, Kruskal Wallis rand sum test and Spearman rank correlation were used to analysis the data form immunohistochemistry staining .The t test, ANOVA and Pearson correlation was used to analysis the data form flow cytometry.P value less than 0.05 was considered statistically significant.Results: Every case of glioma examined showed PCNA positive cells.