The Expression And Significance Of BRD4 And EZH2 In Gastrointestinal Stromal Tumor

Objective:To investigate the relationship between the expression of bromoid domain protein 4(BRD4),enhancer of zeste homolog 2(EZH2)in gastrointestinal stromal tumor(GIST)and the clinicopathologic characteristics and prognosis of GIST,and to analyze the correlation between the expression of BRD4 and EZH2 protein in GIST.Methods:The En Vision two-step immunohistochemical method was used to detect the expression of BRD4 and EZH2 in 112 cases of GIST and the corresponding normal tissue;SPSS25.0 software was used to analyze the expression of BRD4,EZH2 in GIST and their relationship with clinicopathologic characteristics and prognosis of GIST,and analyze the correlation between the expression of the two protein.Results:(1)The expression of BRD4 protein was high in 62 cases of the 112 GIST tumor tissue(55.36%,62/112);the expression of BRD4 protein was high in 27 cases of the corresponding normal tissue(24.11%,27/112).The expression of EZH2 protein was high in 61 cases of the 112 GIST tumor tissue(54.46%,61/112);the expression of EZH2 protein was high in 22 cases of the corresponding normal tissue(19.64%,22/112).The expression of BRD4 and EZH2 protein in GIST tumor tissue were higher than those in the corresponding normal tissue,and the difference was statistically significant(P<0.05).(2)The expression of BRD4 and EZH2 protein in the 112 cases of GIST were significantly different among different tumor diameter,mitotic figure and risk group(P<0.05).The high expression rate of the two protein in group with the tumor diameter more than 5 cm was higher than that in group with the tumor diameter less than or equal to 5 cm(P<0.05),and the high expression rate of the two protein in group with mitotic figure more than 5/50 HPF was higher than that in group with mitotic figure less than or equal to 5/50 HPF(P<0.05).The high expression rate of the two protein in the middle or high risk groups was higher than that in the extremely low risk and low risk groups(P<0.05).But there was no significant difference in the expression level of BRD4,EZH2 protein between different group of sex,age and primary site of the tumor(P>0.05).(3)There was a positive correlation between the expression of BRD4 and EZH2 protein in GIST tumor tissue(r=0.189,P<0.05).(4)The expression of BRD4 and EZH2 protein is not related to the prognosis of the cases of GIST(P>0.05).Conclusions:The increased expression of BRD4 and EZH2 protein in GIST tumor tissue may promote the occurrence and development of GIST,and can be used to evaluate the malignant potential of GIST to a certain extent.The expression of BRD4 protein was positively correlated with that of EZH2 protein in GIST.