Expression Of Somatostatin Receptor Subtypes In Esophageal Carcinoma And Its Clinical Significance

Objective:To detect the expression of somatostatin receptor subtypes in the specimens of esophageal carcinoma and discuss the relationship between the expression and characteristics of the tumor.Methods:Immunohistochemical staining of somatostatin receptor subtypes1-5,p53 and ki-67 was performed by the standard streptavidin-peroxidase(SP) technique for the paraffin sections of 86 esophageal carcinomas. The proliferation index in esophageal carcinoma tissues was calculated by the ki-67 labeled nuclei ratio that was given as a ratio of nuclear staining to the total number of cell counted.The relationship between the expression rate of somatostatin receptor subtypes and the clinicopathological parameters,p53 expression or the proliferation index was analyzed.Results:一, The expression of somatostatin receptor subtypesThe expression rate of somatostatin receptor subtypeI,subtype2 and subtype5 in the specimens of esophageal carcinoma was 68.6%(59/86),22.1%(19/86) and 18.6%(16/86) respectively,but no expression of somatostatin receptor subtype3 and subtype4 was detected in these samples. The expression rate of the tumor in different groups,such as patients of different sex,tumor size,location,histological grade, lymphonode metastasis and pathological stage,showed no difference(p>0.05). 二, Correlation between expression of somatostatin receptor subtypes andp53 expressionThe positive rate of p53 expression in esophageal carcinoma was 66.3%.In the specimens of esophageal carcinoma with p53 positive expression, the positive rate of SSTR1, SSTR2, SSTR5 was 63.2%,24.6% and 22.8% respectively; In the specimens with p53 negative expression, the positive rate of SSTR1, SSTR2, SSTR5 was 79.3%, 13.8% and 10.3% respectively,which showed no correlation between somatostatin receptor subtypes expression and p53.三, Correlation between expression of somatostatin receptor subtypes and the proliferation indexThe expression rate of ki-67 in esophageal carcinoma was 81.4%(70/86).The mean proliferation index in the samples with SSTR2 positive expression was 24.25% ±11.42%, and the mean proliferation index in the samples with SSTR2 negative expression was 33.35%± 18.15%, which showed significant difference(p<0.05). The mean proliferation index in the samples with SSTR2 positive expression was lower than that of samples with SSTR2 negative expression. The mean proliferation index in the samples with SSTRl positive expression was 30.61%± 17.52%, and the mean proliferation index in the samples with SSTRl negative expression was 33.02% ± 16.83%, which showed no difference(p>0.05). The mean proliferation index in the samples with SSTR5 positive expression was 31.68%±14.25%, and the mean proliferation index in the samples with SSTR5 negative expression was 31.26%± 17.96%, which showed no difference(p>0.05). Conclusion:The mainly expression of somatostatin receptor subtypes in esophageal carcinoma was subtype 1. The expression rate of all the subtypes showed no correlation with the histological grade, p53 and pathological stage of the tumor. SSTRl and SSTR5 may not exert an inhibitory action on esophageal tumor cell multiplication.The expression of SSTR2 showed inverse correlation with the proliferation index,which indicated that SSTR2 may play an important role in the regulation of cell life cycle so as to inhibit esophageal tumor cell proliferation and tumor growth.