| Glioma is the most common intracranial malignant tumor in human, It accounts for approximately 50%-60% of the adult primary brain tumors. Annual incidence rate among adults is 8/100, 000. High malignant glioma showed infiltrative growth, surgical treatments are not good enough because it is very easy to recurrence in postoperative. Nowadays, The treatment of glioma is still recognized worldwide problem. With the development of technology, human understand glioma more and more. Many scholars studied extensively about the occurrence, development and prognosis of glioma, but they have not yet to fully understand its pathogenesis until now. Therefore, it is very necessary to study molecular biology mechanisms of human glioma further. In this study, we want to explore the role of PTEN and COX-2 in the occurrence, development and prognosis of human glioma, and provide theoretical basis for early diagnosis and treatment by observing the expression of PTEN and COX-2 in human glioma tissues and its relationship with the biological characteristics of glioma.PTEN was discovered in 1997, which is recognized as an important tumor suppressor gene following the p53 gene. PTEN has dual specificity phosphatase activity and its mutation and inactivation are related with a variety of human cancers. PTEN located on human chromosome 10q23.3, which consist of 9 exons and 8 introns and total length was about 200kb. The protein encoded by PTEN contains 403 amino acids, mainly in the cytoplasm and nucleus. They presented higher expression level in human multiple organizations, especially in the heart, brain, lung, liver and kidney and other tissues are. As a tumor suppressor gene, PTEN involved in regulating apoptosis mainly through its lipid phosphatase activity and made cell cycle arrest in G1 phase. These effects prevented cell growth and promoted apoptosis. Furthermore, PTEN can also inhibited the occurrence and development of tumor by inhibiting angiogenesis, suppressing tumor invasion and metastasis development.COX-2 is a key rate-limiting enzyme in the process of prostaglandin synthesis. Study shows the over-expression of prostaglandin was common feature of many early tumors formation. Epidemiology, experimental zoology and cytology test, and many studies show that, COX-2 involved in maintaining the body's various physiological and pathological processes and its over-expression are related with a variety of tumors closely.COX-2 was an inducible enzyme and involved in various pathophysiological process. Physiological state, it was not expressed in most cells, only can be produced rapidly in some cells through extensive stimuli inside and outside cells. Studies show that after receiving stimuli COX-2 expression level increased tens of times within 24 hours. COX-2 play an important role in tumor growth and metastasis, so it related with invasiveness of glioma and clinical prognosis closely.Objective: Methods: First, we collected 50 samples of preserved human gliomas during 2005~2008, which come from the operation of the First Hospital of Jilin University and confirmed by postoperative pathology.29 samples are males and 21 samples are females. Age ranged from 4-67 years, average 38.7years. All the samples have not received radiation or chemotherapy. 10 cases of normal brain tissues obtained were used as a contrast. Then, the SP immunohi- stochemical method was used to determine the expression of PTEN and COX-2 in human gliomas and normal brain tissues. Finally, we use SPSS17.0 to analyse the relationship between the expression of PTEN and COX-2 in human gliomas and malignant degree of glioma.Results: The expression of PTEN and COX-2 were varied among different grades of gliomas. With the ascending of the glioma grades, the positive expression rate of PTEN was decreased gradually. Gradeâ… 80.0%, gradeâ…¡60.0%, gradeâ…¢33.3%, gradeâ…£14.3%. The difference of expression level amongâ… ,â…¡grade andâ…¢,â…£were statistically significant. With the ascending of the glioma grades, the positive expression rate of COX-2 was increased gradually. Gradeâ… 20.0%, gradeâ…¡35.0%, gradeâ…¢66.7%, gradeâ…£71.4%. The difference of expression level amongâ… ,â…¡grade andâ…¢,â…£were statistically significant.Conclusion: With the increase of glioma grades, the positive expression rate of PTEN decreased gradually. On the contrary, the positive expression rate of COX-2 increased gradually. PTEN and COX-2 in human gliomas were negatively correlated. There were some interaction between them probably. Combined detection of PTEN and COX-2 may have an important reference value in diagnosis, treatment and prognosis of glioma.
|
PDF Full Text Request