Investigation Of Relationship Between EZH1 And PTEN With The Process And Prognosis Of Glioma

Background and Objective Glioma, which mainly originates from glial cells at neural ectoderm, is one of the most common primary tumors in central nervous system. Of all the intracranial tumor, brain glioma accounts for about 40%. Glioma is a kind of malignant tumor that has long invasion period and cannot be separated from surrounding tissues successfully, so it is very difficult to get the clinical effect by surgery. Besides, because of the rapid cancer cell multiplication, other treatments such as radiotherapy and chemotherapy cannot receive the expected curative effect either. Patients with glioma usually have no long life or high quality of life. Phosphatase and tensin homolog deleted on chromosome ten(PTEN) is a kind of tumor suppressor gene that can inhibit the proliferation and migration of tumor cells and induce the apoptosis of tumor cells, in order to achieve the purpose of tumor inhibition. Reasons such as the loss of PTEN gene(heterozygosity loss or homozygosity loss), abnormal methylation and mutation will all lead to PTEN gene inactivation, causing abnormal proliferation of cells. Enhancer of zeste homolog 1(EZH1), which belongs to the Pc G(Ploycomb group) famliy, is a new type of human genes. EZH1 is found excessive expression in some cancer, such as hepatocellular carcinoma, breast cancer, prostate cancer and so on. EZH1 has a close relationship with the development and prognosis of tumors. This experiment is to test the expression of EZH1 and PTEN in glioma, in order to study the corrlelation between EZH1 with PTEN in glioma, and to study the influence of EZH1 and PTEN on the prognosis of patients with glioma. This study can offer reference for the diagnosis, treatment and prognosis of glioma in clinic.Methods 41 patients which were pathological diagnosed as glioma and with complete clinical data were chosen, and the fresh tumor samples from glioma neurosurgery were collected. All the 41 patients were first onset and had no surgery, radiotherapy, chemotherapy or other treatment before surgical treatment. 15 tumor inactivation healthy brain tissue from other brain surgeryswere collected as control. Immunohistochemical method was used to test the expression of the EZH1 and PTEN in the 41 glioma tissues and 15 tumor inactivation healthy brain tissues. The corrlelation between EZH1 with PTEN in glioma and the influence of EZH1 and PTEN on the prognosis of patients with glioma were studied.Results 1. In all the 41 glioma tissue samples, pathologic stage I-II had 14 cases, stage II had 7 cases, stage III had 8 cases and stage IV had 12 cases. There were 15 tumor inactivation healthy brain tissues. EZH1 and PTEN had levels of expression in glioma tissue samples and tumor inactivation healthy brain tissues. 2. The positive rate of EZH1 in glioma tissue samples was 85.36%(35/41 cases), mainly in the nucleus, and most with cytoplasmic staining(73.17%, 30/41 cases). The positive rate of EZH1 in tumor inactivation healthy brain tissue samples was 26.67%(4/15 cases), and all in the nucleus. The positive rates of EZH1 in nucleus and cytoplasmic staining of glioma tissue samples were significantly higher than that in tumor inactivation healthy brain tissue samples(P<0.05). 3. PTEN located in the nucleus. The positive rate of PTEN in glioma tissue samples was 46.34%(19/41 cases). The positive rate of PTEN in tumor inactivation healthy brain tissue sanples was 93.33%(14/15 cases). The positive rates of PTEN in glioma tissue samples were significantly lower than that in tumor inactivation healthy brain tissue samples(P<0.05). 4. In the low pathological staging glioma tissue samples, the EZH1 positive rate was 71.43%(15/21 cases) and in the high pathological staging glioma tissue samples, the EZH1 positive rate was 100.00%(20/20 cases). The difference between the two groups had statistical significance(χ2=6.69, P<0.05). With the increasing of the pathological staging, the EZH1 positive expression was also increased. 5. In the low pathological staging glioma tissue samples, the PTEN positive rate was 66.67%(14/21 cases) and in the high pathological staging glioma tissue samples, the PTEN positive rate was 25.00%(5/20 cases). The difference between the two groups had statistical significance(χ2=7.15, P<0.05). With the increasing of the pathological staging, the PTEN positive expression was decreased. 6. The rank correlation analysis was taken between the expressiong of EZH1 and PTEN in 41 glioma tissue samples. The Spearman rank correlation coefficient was-0.432, P<0.05. EZH1 and PTEN were negatively correlated in glioma tissue samples. 7. The Logistic regression analysis showed that at the P=0.05 level, glioma pathological staging, expression of EZH1 and expression of PTEN were the main factors affecting grognosis.Conclusions 1. In glioma tissue samples, both EZH1 and PTEN were expressed. The expression of EZH1 in glioma tissue samples was higher than that of the tumor inactivation healthy brain tissue samples and the expression of PTEN in glioma tissue samples was lower than that of the tumor inactivation healthy brain tissue samples. 2. The expression of EZH1 and PTEN closely correlated with the pathological staging of glioma, with the increasing of the pathological staging, the EZH1 positive expression was increased and the PTEN positive expression was decreased.3. EZH1 and PTEN were negatively correlated in glioma tissue samples. 4. The glioma pathological staging, expression of EZH1 and expression of PTEN were the main factors affecting grognosis. The glioma pathological staging and expression of EZH1 were risky factors, while the expression of PTEN was protective factor.