Expression And Significance Of SASH1 Protein And E-cadherin In Small Cell Lung Cancer

OBJECTIVE:To investigate the expression of candidate tumor suppressor gene SASH1(SAM--and SH3-domain containing 1)and E-cadherin in small cell lung cancer(SCLC),and to analyze the correlations of SASH1 and E-cadherin expression with clinicopathological factors and prognosis in SCLC.And further to analyze the correlations between the expression of the two proteins in the cancer tissue of SCLC patients.METHODS:The expression of SASH1 and E-cadherin was detected by immunohistochemistry in50 SCLC cancer tissues and 50 cancer-adjacent tissues.Use SPSS20.0 statistical software to perform χ2 test,to analyze the expression of SASH1 and E-cadherin in small cell lung cancer and their influencefactors.Spearman was used to analyze the correlation between the expression of the two proteins in cancer tissues of SCLC patients.The factors affecting postoperative OS of patients were analyzed by COX regression.RESULTS:1.The positive expression rate of SASH1 protein in small cell lung cancer tissues was 44.00%,and the positive expression rate in adjacent tissues was 74.00%,which was statistically significant(χ~2=9.301,P=0.002).Besides,the positive expression rate of E-cadherin in small cell lung cancer tissues was 48.00%,and the positive expression rate in adjacent tissues was 80.00%,which was statistically significant(χ~2=11.111,P=0.001).2.Univariate analysis showed that there were significant differences in SASH1 protein and E-cadherin in lymph node,TNM stage,tumor size(T: tumor length,unit cm),and CEA in patients with small cell lung cancer(P<0.05).There were no significant differences in gender,age,smoking history and NSE(P>0.05).The results of multivariate analysis showed that the two independent influencing factors of SASH1 protein expression were tumor size and CEA,and the independent influencing factors of E-cadherin expression were TNM stage and tumor size.3.The results of correlation analysis between SASH1 protein and E-cadherin showed that the correlation coefficient was 0.519(P<0.001),indicating that the expression of SASH1 protein was positively correlated with the expression of E-cadherin.4.COX regression univariate analysis showed that tumor size,lymph nodes,TNM stage,extent of lung resection,prophylactic cranial irradiation,SASH1 protein,E-cadherin were associated with prognosis(OS),and the difference was statistically significant(P <0.05).There was no significant correlation between gender,age,smoking history,NSE,CEA and prognosis(OS)(P>0.05).Multivariate analysis showed that SASH1 protein,E-cadherin and TNM stage were independent prognostic factors in patients with small cell lung cancer after surgery.CONCLUSION:1.The expressions of SASH1 protein and E-cadherin were downregulated in SCLC,and their expression levels were correlated with clinicopathological characteristics.They were independent prognostic factors to SCLC after surgery.The downregulated expressions of both proteins may be related to the occurrence,development and prognosis of SCLC.2.The expression of SASH1 protein and E-cadherin in SCLC is positively correlated,and the two may have a synergistic effect in the progression of SCLC.