Relationship Between Expression Of SATB2 And S100p And Clinicopathological Characteristics Of Colorectal Cancer

Objective:To investigate the relationship between the expression of SATB2 protein and S100 P protein in human colorectal cancer tissues and the clinicopathological characteristics,epithelial-mesenchymal transformation(EMT)related proteins and DNA mismatch repair protein(MMRP).And further observe whether there is a certain relationship between the two and KRAS,NRAS,BRAF gene mutations.Methods:A total of 144 cases of postoperative specimens and adjacent tissues of colorectal cancer were randomly selected from Yuhuangding Hospital Affiliated to Qingdao University from January 2019 to June 2019.The expression of SATB2,S100 P and EMT-related proteins(β-catenin,E-cadherin)and MMRP(MLH1,MSH2,PMS2,MSH6)were observed by immunohistochemical method.The correlations of SATB2 and S100 p with EMT-related proteins and MMRP were analyzed.The mutations of KRAS,NRAS and BRAF genes in 44 cases of colorectal cancer tissue samples were detected by real-time quantitative PCR,and the relationship between SATB2 and S100 P proteins and the above gene mutations was further analyzed.Results:(1)The positive expression rate of SATB2 in colorectal cancer tissues was 84%,which was lower than that in adjacent mucosal tissues(97.9%)(X2=16.911,P < 0.01).SATB2 was strongly positive(41.67%),moderately positive(34.03%),weakly positive(8.33%),and negatively expressed(15.97%)in colorectal cancer tissues,while strongly positive(97.9%)in adjacent mucosal tissues(X2=109.026,P<0.01).SATB2 was associated with the degree of differentiation and lymph node metastasis of colorectal cancer(P<0.05),and SATB2 was low expressed in poorly differentiated colorectal cancer tissues with lymph node metastasis.(2)The positive expression rate of S100 p in colorectal cancer tissues was 63.9%,which was higher than that in adjacent mucosal tissues(4.2%)(X2= 114.396,P<0.01),and was correlated with the degree of differentiation of colorectal cancer and lymph node metastasis(P<0.05).S100 p was highly expressed in poorly differentiated colorectal cancer tissues with lymph node metastasis.(3)The expression of SATB2 and S100 P in colorectal cancer tissues was negatively correlated(RS =-0.209,P=0.012 < 0.05).(4)In colorectal cancer tissues,with the decrease of SATB2 expression,the abnormal expression of β-catenin increased and the positive expression of E-cadherin decreased(rs=-0.321,P < 0.01;rs =0.270,P <0.01).The expression of S100 p was positively correlated with the abnormal expression ofβ-catenin(rs=0.222,P < 0.05),and had no correlation with the positive expression of E-cadherin(rs=-0.046,P > 0.05).(5)Mismatch repair protein deletion occurred in 14cases(9.7%)of 144 cases of colorectal cancer,including 7 cases(4.9%)of both PMS2 and MLH1 protein deletion,2 cases(1.4%)of both MSH6 and MSH2 protein deletion,and 4 cases(2.8%)of PMS2 protein deletion alone.MSH6 protein deletion was found in 1 patient(0.6%).(6)The loss of expression of PMS2 protein and MLH1 protein was related to tumor location and size(P < 0.05),the loss of expression of MSH6 protein was related to tumor size(P < 0.05),but there was no correlation between the expression of MSH2 protein and the clinicopathological characteristics of tumor(P>0.05).(7)SATB2 protein expression was correlated with MSI(X2=9.949,P < 0.05),while S100 P protein expression was not correlated with MSI(P>0.05).(8)Mutation rates of KRAS,NRAS and BRAF were 45.5%,2.3% and 15.9%,respectively.There was no correlation between the expression of SATB2 and S100 p and the mutations of these three genes(P > 0.05).Conclusion:(1)Abnormal activation or inactivation of SATB2 and S100 P genes may be involved in the occurrence and progression of colorectal cancer.Combined detection of the expression levels of SATB2 and S100 P proteins in colorectal cancer can reflect the biological behavior and prognosis of colorectal cancer.(2)Abnormal expression of SATB2 and S100P protein may cause the down-regulation of E-cadherin expression and the abnormal expression of β-catenin,promote the occurrence of EMT in colorectal cancer,and lead to tumor differentiation,proliferation and metastasis.(3)SATB2 protein expression was correlated with MSI in colorectal cancer,and SATB2 protein expression level could indirectly reflect MSI status.(4)The expression of SATB2 and S100 p was not related to KRAS,NRAS and BRAF gene mutations,and had no guiding significance for the drug therapy of colorectal cancer.