| Background and purpose:Glioma,the most common adult central nervous system primary refractory malignant tumor with the incidence rate of about 5-6 /10 million,is the main cause of death in patients with intracranial tumors.With an aging population the incidence of glioma is increasing,glioma brings a heavy burden on society and the family,seriously harms human health.World Health Organization divides gliomas into four grades,GBM is the highest degree of malignancy and the highest incidence of glioma,82% of malignant glioma pathology is glioblastoma.Currently the standard treatment for glioma is resection combined with adjuvant chemotherapy and radiotherapy.For standardization of treatment,the patient's overall survival time is extended to some extent.As the proliferation of malignant glioma,highly recurrent,malignant invasion characteristics,temozolomide and other drug resistance,resistance to chemotherapy or radiotherapy and other factors,the overall treatment effect of GBM patients has no breakthrough.Almost all patients inevitably relapse,with a median survival of only 12 to 15 months,5-year survival rate of only 4.7%.To improve the prognosis of glioma patients,and to explore new ideas and therapeutic drugs become neurosurgery problems and concerns.The occurrence,development,invasion and recurrence of glioma involves many genes and proteins.Molecular biology,genomics,and proteomics provide a convenient tool for exploring the molecular pathology of malignant proliferation of tumors.Molecular targeted therapies against key molecules of tumorigenesis,promote apoptosis,inhibit tumor formation,have become the focus of cancer treatment research.The new type of glioma pathology combines tissue cell morphology and genetic testing,doctors decide targeting drug depend on the different genotyping.Monoclonal antibody(bevacizumab,etc.)and small molecule kinase receptor inhibitors are the main targets of the current drug,with high specificity and low toxic side effects,have more clinical value than the traditional cytotoxic chemotherapy drugs.As mutations of multiple genes in the development of GBM,the efficacy of targeting individual molecules is unsatisfactory,single drug is easy to produce drug resistance for long term chemotherapy.Therefore,it is very important to elucidate the molecular mechanism of malignant proliferation of glioma,and to find the key molecular targeting for the development of glioma.Gene chip,second-generation sequencing technology and tumor gene database provide strong support for study of tumor molecular mechanisms.Ubiquitin-proteasome system is the main way inside most eukaryotic intracellular protein degradation.Deubiquitination(DUBs)can act on the ubiquitinated protein,ubiquitin molecules dissociate reverse from ubiquitination process,so that the substrate is not degraded by the proteasome.The ubiquitinase can modify the ubiquitin precursors to hydrolyze the proteasome complex and the cytoplasmic ubiquitin chain,so that the ubiquitin molecules are stable and viable in the cell.Ubiquitinase is involved in many important biological processes,such as cell cycle regulation,DNA damage repair,nuclear chromatin recombination,regulatory cell signaling pathways.The interactionof ubiquitination and de-ubiquitination involves in the regulation of oncogenes,tumor suppressor genes,oncogenic signaling pathway molecules and other proteins,regulates tumor's occurrence,development,migration,invasion,recurrence process.The ubiquitin carboxy terminal hydrolase family is an important deubiquitination enzyme,including UCH-L1,UCH-L3,UCH37,BAP1(BRCA1-related protein 1).Studies have shown that UCH37 is related to malignant proliferation of ovarian cancer,multiple myeloma,liver cancer,UCH37 promotes tumor recurrence and leads to poor prognosis,but experimental study on the relationshio between proliferation of malignant glioma and UCH37 has not been reported.Therefore,the purpose of this study is to use multivariate information to verify the differential expression of UCH37 in glioma and the value of evaluating the prognosis of glioma,and to explore the mechanism of UCH37 in malignant proliferation of glioma in vitro experiments.This paper is divided into two parts:Part I: Expression of UCH37 gene in brain glioma tissue microarray and its correlation with prognosisA total of 300 cases of glioma samples from 16 cases of normal brain tissue were collected from Shanghai Changzheng Hospital.All samples were prepared to be made for high-throughput tissue microarray.The clinical data of the patients were collected and the patients were followed up for postoperative radiotherapy and chemotherapy and survival.The effect of UCH37 expression on the prognosis of the patients was analyzed by immunohistochemistry.At the end of follow-up,the overall survival time of patients with glioma was 31.96 ± 26.82 months,the progression-free survival was 29.19 ± 25.96 months;the survival rate of patients was 39.1%,35.6% of patients did not have imaging progress.Immunohistochemical results showed that UCH37 expression in glioma tissue was significantly higher than that in normal brain tissue in glioma.Immunohistochemistry expression score of UCH37 in glioma tissue was 1.905 ± 1.935,in the normal brain tissue was 0.42 ± 1.04,there was a significant statistical significance(p <0.0010).With Kaplan-Meier survival curve we study UCH37 expression and survival of patients,The median OS with high and low expression of UCH37 in glioma was 20 months and 40 months;the median PFS with high and low expression of UCH37 in glioma was 19 months and 30 months(OS: p <0.001;PFS: p <0.001).Respectively,the OS and PFS were significantly lower in the high expression group(P <0.001).Further studies in patients with primary glioblastoma showed that UCH37 was significantly overexpressed in primary GBM tissue(p <0.001),and survival in primary GBM with high expression of UCH 37 was shorter(OS: 10 months vs 12 Month,p <0.001;PFS: 11 months vs 8 months,p <0.001).Cox multivariate risk regression found that UCH37 was the independent factor determing prognosis of primary GBM patients' OS(Hazard Ratio =2.050,95%CI 1.243-3.380,p=0.005)and PFS(Hazard Ratio = 2.135,95%CI 1.291-3.531,p=0.003).GBM patients under chemotherapy primary with high expression of UCH37 had a shorter survival(OS: 9 months vs15 months,p <0.001;PFS: 7 months vs11 months,p <0.001),primary GBM patients receiving radiotherapy with high expression of UCH37 had shorter survival(OS: 10 months vs15 months,p <0.001;PFS: 7 months vs12 months,p <0.001).The results suggest that UCH37 expression is related to the sensitivity of radiotherapy and chemotherapy in primary GBM patients.Part II: Study on the mechanism of UCH37 gene regulation on malignant proliferation of gliomaIn order to study the cytological function of UCH37 in the proliferation process of glioma,we used lentivirus transfection method to interfere and overexpress UCH37 in brain glioma cell line U87,and to set empty plasmid as control.UCH37 interference and overexpression were verified by the second generation sequencing method.The expression levels of UCH37 m RNA and protein were confirmed by quantitative PCR.The expression of UCH37 was observed by CCK-8 method.The cell proliferation curve was drawn by CCK-8 method.We found that the proliferation of glioma cells was significantly increased in UCH37 overexpression group compared with the control group,and the proliferation rate of glioma cells decreased significantly and the cell cycle was blocked in the S phase in UCH37 knockdown group.Conclusion:In summary,we found that UCH37 gene was highexpression in glioma tissue and correlation with the clinical prognosis of patients by analyzing the tissue microarray combined with clinical information,UCH37 can help determine the clinical prognosis of glioma patients,is an independent prognosis predictor of primary GBM patients and affects the sensitivity of radiotherapy and chemotherapy in the primary GBM patients.UCH37 can promote the malignant proliferation of glioma cells by in vitro experiments.Therefore,UCH37 can be further researched as a molecular target for predicting the clinical prognosis of patients with glioma. |
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