Expression Of Cyclin B1 And Its Relationship With Cellular Proliferation In Human Brain Glioma

Objective:To study the expression of Cyclin B1 in human gliomas and its relationship with cellular proliferation activity.Methods:Samples used in this study were from consented patients admit-ed to our hospital between 2001 and 2004. The histopathological diagnosis and grade of the 62 tumor were confirmed by two pathologists separately and were retrospectively reviewed, according to the classification criteria of central nervous system tumors established by WHO in 2000. A total of 62 gliomas archival paraffin blocks with enough sample size were collected (grade I:9 caces, gradeⅡ:15 cases, gradeⅢ:20 cases, and grade IV:18 cases). All blocks were cut into 5-μm-thick sections on a microtome.14 normal human brain tissue archival paraffin blocks were provide by the specimen bank of our hospital. The expression levels of Cyclin B1 protein and proliferating cell nuclear antigen (PCNA) were detemined by immunohistochemistry SABC methods.Results:In glioma cells, Cyclin B1 was localized mainly in the nucleus, and its positive rate was 53.2%(33/62). Although the positive rates and mean labeling indices showed a tendency of increasing with pathological grades, no remarkable positive rate difference was seen between different grades (P>0.05). There were significance PCNA differences between gradeⅠ,ⅡandⅣ(P<0.05), grade I and III (P<0.05). In the normal control brain tissues, its positive rate was 7.1%. Along with the increase of PCNA, Cyclin B1's expression increased markedly. Bivariant correlation analysis revealed that there is a significant positive correlation between Cyclin B1 and PCNA (r=0.705, P<0.01).Conclusion:1,Expression of Cyclin B1 is correlated with the pathological grades in human brain glioma.. Cyclin B1 was overexpressed in glioma cells. Among them, Cyclin B1 is closely related with initiation and progression of human glioma.2,There is a significant positive correlation between Cyclin B1 and PCNA. These findings showed that Cyclin B1 was closely related with malignant progression and proliferation activity of glioma. It may be an important factor in promoting the cell transformation to malignant phenotype.3,Glioma patients with cyclin B1 expression had poorer prognosis than those without expression, which demonstrated that cyclin B1 is closely with the outcome of patients and can be used as an index for predicting prognosis.