Expression And Significance Of STAT3 And Its Phosphorylation, SOCS3 And Its DNA Methylation In Esophageal Squamous Cell Carcinoma

Objective By testing the expression of signal transducer and activator of transcription 3 (STAT3) in esophageal squamous cell carcinoma (ESCC) tissue at mRNA, protein and protein phosphorylation levels, we studied the function of STAT3 in the occurrence, development, invasion and metastasis of ESCC.Methods By using adjacent normal esophageal tissue as control, the expression of STAT3mRNA, STAT3 and phosphorylated STAT3 (pSTAT3) in 43 cases of ESCC was studied by Real-Time PCR and Western Blot, and subsequently analyzed to find out the correlation with Clinical Pathological Parameters.Results (1) Remarkably higher relative expression intensity of STAT3 at mRNA was found in ESCC tissue( 1.43±0.59) , compared with normal esophageal tissue(0.98±0.47)(P<0.05);STAT3 and pSTAT3 expression in ESCC (2.16±0.39;1.40±0.15)was also significantly higher than normal tissue( 1.87±0.29;1.25±0.13)(P<0.05). (2) Statistical differences were found in different differentiation degrees of tumor for the expression of STAT3mRNA, STAT3 and pSTAT3 in ESCC. The lower differentiation degree, the higher the expression( P< 0.05) . The expression was negatively correlated with differentiation degree of tumor( -1< r<-0.301,P<0.05), while it had a positive relationship with TNM staging and lymph node metastasis( 0.301< r< 1,P< 0.05).In TNM staging, higher expression was found in StageⅢthan both StageⅠand StageⅡ( P< 0.05), and the expression in the group with lymph node metastasis was higher than that in the group without lymph node metastasis( P< 0.05). No obvious connection was found with the age, gender, family history and smoking history of patients( P> 0.05) .Conclusion Higher expression of STAT3 and pSTAT3 in ESCC tissue indicated close correlation with the differentiation, invasion and metastasis of ESCC. pSTAT3 is more significant.Testing of pSTAT3 might provide ideal target for gene therapy of esophageal cancer. Objective By testing the expression of suppressor of cytokine signaling 3 (SOCS3) in esophageal squamous cell carcinoma (ESCC) tissue at DNA methylation, mRNA and protein levels, we studied the function of SOCS3 in the occurrence, development, invasion and metastasis of ESCC.Methods In this study, by using adjacent normal esophageal tissue as control, the expression of SOCS3 DNA methylation, SOCS3 mRNA and SOCS3 protein in 43 cases of ESCC was detected by MSP, Real-Time PCR and Western Blot, and subsequently analyzed to find out the correlation with Clinical Pathological Parameters.Results (1) The positive rate of SOCS3 DNA methylation in ESCC( 79.1%) was significantly higher than normal tissue( 14.0%)( P< 0.01). (2) Remarkably lower relative expression intensity of SOCS3 mRNA was found in ESCC tissue (0.53±0.30), compared with normal esophageal tissue(1.15±0.44)( P﹤0.01) . In ESCC, the SOCS3mRNA expression was notably lower in methylation group(0.45±0.24) than non-methylation group(0.86±0.29)( P<0.05). (3) SOCS3 protein expression in ESCC(1.66±0.22) was also evidently lower than adjacent normal tissue (1.83±0.15)( P <0.01). In ESCC, the SOCS3 expression was notably lower in methylation group(1.61±0.21) than non-methylation group(1.87±0.15)( P <0.01). (4) Expression of both SOCS3mRNA and SOCS3 in ESCC was positively correlated with differentiation degree ( P < 0.05 ) , while it had a negative correlation with TNM staging and lymph node metastasis( P< 0.05) . No obvious connection was found with the age, gender, family history and smoking history of patients( P> 0.05) .Conclusion The decrease of SOCS3 gene expression in ESCC was caused by the high positive rate of SOCS3 DNA methylation, which was closely connected with the differentiation, invasion and metastasis of ESCC. The detection of SOCS3 DNA methylation,SOCS3mRNA and SOCS3 expression in ESCC could provide important index in diagnosis of the malignant degree and biological behavior of esophageal squamous cell carcinoma.