A Study On Clinical Significance Of Hsp27,P-hsp27 And MCM6 In Glioma

Part 1 Study on clinical significance of Hsp27 and p-Hsp27 expression in gliomaAims:To investigate the expression of heat shock protein 27(Hsp27)and phosphorylated heat shock protein 27(p-Hsp27)in glioma and their correlation with clinicopathological parameters.Patients and methods:We detected the heat shock protein 27(Hsp27),phosphorylated Hsp27(p-Hsp27),ATRX and IDH1R132H proteins using immunohistochemistry in 421 glioma tissues.And we assessed the relationship between molecular alterations and clinicopathological parameters.Kaplan-Meier survival curves were constructed,and differences were detected by the log-rank test.Results:Positive immunostaining of Hsp27 and p-Hsp27 was mainly located in the cytoplasm of tumor cells.However,no Hsp27 or p-Hsp27 immunostaining was observed in non-neoplastic tissue.Strong Hsp27 expression was detected in 10.4%,20.0%and 25.1%of grade 2,3 and 4 tumors,respectively.Additionally,strong p-Hsp27 immunostaining was detected in 23.1%of grade 3 tumors and 23.7%of grade 4 tumors;however,only 2.6%of grade 2 tumors stained positively.A statistically significant difference was observed between expression of Hsp27 and p-Hsp27 and glioma grade(p=0.012 and p<0.001,respectively).We found that Hsp27 and p-Hsp27 were mainly expressed in aggressive astrocytic gliomas and negatively associated with ATRX loss(ATRX-)and IDH1R132H mutation status.However,neither Hsp27 nor p-Hsp27 expression was related to survival time for any grade of glioma.Interestingly,p-Hsp27 was mutually exclusive with ATRX loss and the IDH1R132H mutation.We classified glioblastomas(GBMs)into three subtypes:ATRX-/IDH1R132H,high p-Hsp27 expression(p-Hsp27+)and none of these three markers.ATRX-/IDH1R132H showed the longest median survival(19.6 months).Patients with high p-Hsp27 expression had a better prognosis than those without any alteration in the three proteins(15.0 vs 13.1 months,P=0.045).Moreover,p-Hsp27+predicted better sensitivity for standard therapy among GBMs without the IDH1 mutation and ATRX loss(26.3 vs 15.5 months,P=0.008).Conclusion:Both Hsp27 and p-Hsp27 are highly expressed in gliomas and closely related to clinicopathological features.Moreover,p-Hsp27 was mutually exclusive with ATRX loss and the IDH1R132H mutation,which play an great role in molecular classification of glioma.Thus,p-Hsp27 may have more important significance in the molecular subtype,treatment and prognosis evaluation of glioma.Part 2 Study on clinical significance of MCM6 expression in gliomaAims:Minichromosomal maintenance proteins(MCMs)play a key role in the development of tumors,but there is no conclusion on the expression of MCMs in gliomas.This study aims to analyze the expression of MCMs family members in gliomas and their correlation with clinicopathological parameters.Patients and methods:We first analyzed the correlation among MCMs expression and glioma grade,IDH1 mutation and prognosis in 325 gliomas from the Chinese Glioma Genome Atlas(CGGA)dataset.In addition,another independent glioma dataset(NCC dataset)was used to detect the protein expression of MCMs that overexpressed in transcript level and significantly associated with the malignant behavior of gliomas in 423 glioma tissues by immunohistochemistry.Kaplan-Meier method and Log-Rank test were used to draw the patient's survival curve and compare the differences in prognosis between different groups.Results:Among CGGA gliomas,MCM3,MCM5-7,and MCM9 were highly expressed in gliomas,and the expression levels of MCM3,MCM5,and MCM6 were positively correlated with glioma grades;MCM2,MCM6,and MCM10 were negatively correlated with prognosis both in low-grade gliomas(LGG)and high grade glioma(HGG).Therefore,high expression of MCM6 transcript levels was an unique grade-related marker in the MCM family and negatively correlated with prognosis.Moreover,MCM6 protein was highly expressed in gliomas,and the positive signal was mainly localized in the nucleus,but no positive signal was detected in matched non-neoplastic tissues.Similar to the high level of MCM6 transcription,MCM6 protein expression was positively correlated with grade and negatively correlated with prognosis.High MCM6 transcription expression and high protein expression were independently prognostic risk factors for LGG and HGG(p<0.05).Importantly,a combination of MCM6 overexpression(MCM6+)with IDH1 mutation(IDH1+)further improved the prediction of the prognosis of HGG.Specifically,IDH1+/MCM6-patients exhibited the longest survival(median survival time were 22,0 months and 34.7 months in CGGA and NCC dataset,respectively),IDH1-/MCM6+ patients showed the shortest(median survival time were 8.5 months and 12.0 months in CGGA and NCC dataset,respecti vely).Conclusion:MCM6 is a gene that highly expressed in gliomas,positively correlated with glioma grade,and is an independent prognostic risk factor for high-grade gliomas.A combination of MCM6 overexpression(MCM6+)with IDH1 mutation(IDH1+)further improved the prediction of the prognosis of HGG and thus could Provide instruction for more aggressive treatment of poorly-divided subgroups.