Expression And Clinical Significance Of Snail MRNA And Protein,E-cadherin Protein In Gastric Cancer

Objective To investigate the expression of Snail mRNA and protein,E-cadherin protein in gastric cancer and their relationship with clinical pathological features. To explore their roles in carcinogenesis and progression of gastric carcinoma and to evaluate their clinicopathologic significances. .Methods The expression of Snail and E-cadherin protein was detected by using immunohistochemical S-P method in 96 cases of gastric carcinoma tissue and 80 cases of the para-cancerous mucosa. The expression of Snail mRNA was detected by using in situ hybridization(ISH) in 96 cases of gastric carcinoma tissue and 80 cases of the para-cancerous mucosa.Results⑴.The positive rate of Snail immunostaining in gastric carcinoma (83.3%) was higher than that in adjacent tissue(s41.25%)(P<0.05);There was a difference of the expression rate of Snail among papillary adenocarcinoma,tubular adenocarcinoma,poor differentiated adenocarcinoma and mucoid carcinom(aP<0.05);The expression of Snail was significantly related with the differential degree,histologic type,depth of tumour invasion,lymph node metastasis and distant metastasi(sP<0.05),but they did not correlate with sex,age,tumour size and clinical stage(P>0.05).⑵The positive rate of Snail mRNA was higher in gastric carcinoma(76%)than in adjacent tissues(30%)(P<0.05);There was a difference of the expression rate of Snail mRNA among papillary adenocarcinoma,tubular adenocarcinoma,poor differentiated adenocarcinoma and mucoid carcinoma(P<0.05);The expression of Snail mRNA was significantly related with the differential degree,histologic type,depth of tumour invasion,lymph node metastasis(P<0.05),but they did not correlate with sex,age,tumour size,clinical stage and distant metastasis (P>0.05).⑶. The positive rate of E-cadherin immunostaining in gastric carcinoma (37.5%) was lower than that in adjacent tissues(100%)(P<0.05);There was a difference of the expression rate of E-cadherin among papillary adenocarcinoma,tubular adenocarcinoma,poor differentiated adenocarcinoma and mucoid carcinoma(P<0.05);The expression of E-cadherin was significantly related with the differential degree,histologic type,depth of tumour invasion,lymph node metastasis,distant metastasis and clinical stage(P<0.05),but they did not correlate with sex,age,tumour size(P>0.05).⑷A positive correlation was found between the expression of Snail mRNA and Snail protein(r=0.594,P<0.05);A negative correlation was found between the expression of Snail protein and E-cadherin protein (r=-0.234,P<0.05). Conclusions⑴.The decreased expression of E-cadherin and overexpression of Snail might be important biological markers for malignant transformation and invasion and matastasis of gastric carcinoma. The combined detection of E-cadherin and Snail has positive effects on predicting the invasion and metastasis in gastric carcinoma.⑵.E-cadherin protein expression is regulated mainly at the transcriptional level by Snail protein; The elevation of E-cadherin protein expression is correspondingly the result of up-regulation of Snail.