The Screening And The Signal Pathway Of Protein Signatures In Brain Glioma And Associated Analysis

Objective: Glioma is recognized as the most common diagnosed tumors of centralnervous system，representing50%of all central nervous system tumors. Until now，it isstill not curable. Even though researches in the past many years had discovered manyelements that inducing and developing Glioma，useful biomarkers are still missing.Therefore，it is imperative to find effective biomarkers to provide guidance for diagnosisand treatment. The purposes of our experiment are to screen diagnostic and prognosticprotein targets for glioma，to find its molecular biological mechanisms，to identifythese proteins involved in signal transduction pathways and to establish foundation forfurther studies.Methods: Total proteins were extracted from77gliomas and28normal tissues inthe first hospital and China-Japan union hospital of Jilin university between year2008and2010. The expression level of135proteins and phosphoproteins were analyzed usingProtein Pathway Array (PPA) method. Differentially expressed proteins andphossphoproteins were identified between glioma tissues and normal control tissuesutilizing cluster analysis. We performed proteomic-wide expression analysis usingIngenuity Pathway Analysis (IPA) software and investigated the significant protein andphosphoproteins expression in gliomas signal network. We did ICH staining in77casesof gliomas including Ki-67staining and observed with light microscopy. We obtainedrelationship between different degree of Ki-67and protein expression，the relationshipbetween gliomas protein expression profiling and patients’ clinical features such as age，gender，geographic regions and gliomas diagnostic level. The overall survival factors of77cases of gliomas was analyzed to determine which risk factors affect survival. Results: Our study revealed that63of the135antibodies had protein expressions，with the ratio being47%. In the normal control group consisting of brain tissues andglioma tissues，differential expressions were presented in31proteins，among which21were the most obvious. The classification model composed of the21proteins performed ahigh accuracy rate of91%，when conducting the prediction of the classification betweenthe brain glioma and the normal brain tissues. Though clustering analysis，the21proteins distinctly identified tumor issues from the normal ones. We analyzed31proteinswith differential expression by IPA system and found that they are closely linked tocellular growth，proliferation，death，circulation and even motion. In addition，theseproteins are related to some diseases and disorders，such as cancers， diseases ofrespiratory system， reproductive system，blood and endocrine. The signal transductionnetwork diagram made by IPA system had found changes of5cell signal transductionpathways. Immunohistochemistry dyeing witnessed significant differences among Ki-67dyeings of77glioma patients. Differentially expressed proteins were also found inpatients with different ages， genders， KPS grading， sizes of tumors， WHOpathological levels and pathogenic sites. The study also discovered high expression ofFAS and Cdk4in glioma patients older than50. PCNA，Cdk2，Cdk6，and Cdk4hadincreasing expressions in high grade patients， while cPKCα decreased. The highexpression of PCNA， Cdk2,Cdk6and the Ki-67index(larger than15%) showedprofound meanings. Moreover，the high expressions of cPKCα，Akt，VSV-G，FASand Cdk6were remarkably relevant to the high KPS grading. Our results demonstratedthat the expression levels of PCNA and CDK2affected the risk of glioma prognosis.Factorial analysis showed that the co-expression of PCNK and CDK2could become aindependent risk factor of prognosis. The risk score based on Cdk2and PCNA could beused as evaluation indicators of prognosis in patients with glioma，and patients with highrisk scores had poor prognosis. Meanwhile，Another factor2and KPS also acted as theindependent factor evaluating prognosis.Conclusion:1. It is feasible to detect the protein expression of high quantity glioma specimensand the normal control brain tissues through new high-throughput protein chip technology (PPA). This method could be adapted to detect vast disorders of signal transductionpathway and protein expression in glioma tissues.2. The differently expressed proteins between tumor and normal tissues are relevantto the growth， development， proliferation， death， circulation and motion. Inaddition，these proteins are related to some diseases and disorders，such as cancers，diseases of respiratory system，reproductive system，blood and endocrine.3. In all these different proteins，FAS and Cdk4were related to patients’ ages，cPKCα、PCNA、Cdk2、Cdk6and Cdk4may be connected to pathological grade.Another three protein: PCNA，Cdk2and Cdk6are linked to Immunohistochemicalindicators Ki-67. The proteins could be selected as molecular marks in clinical diagnosisand treatment.4. The combination of PCNK and CDK2could act as one independent factor toestimate prognosis.