Egr-1基因及其相关癌基因蛋白在放疗后食管鳞癌的表达

目的研究早期生长反应基因1（Egr-1基因）在放疗后切除人食管癌组织的表达及其与癌基因蛋白C－fos、C—Jun和Egr-1靶基因蛋白P53、Rb和Bax表达的关系。方法应用原位杂交和免疫组化法分别检测80例非放疗和放疗后外科切除食管鳞状细胞癌Egr－1mRNA、Egr-1、Cfos、C-Jun、P53、Rb和Bax蛋白的表达。结果Egr-1mRNA和Bax蛋白阳性定位于细胞质；而Egr-1、Fos、Jun、P53和Rb蛋白阳性定位于细胞核。40例非放疗和40例放疗后的食管癌切除肿瘤标本均存在Egr-1表达，其中40例例放疗病人外科切除标本Egr-1阳性表达9例（22．5％），40例放疗后病人Egr-1阳性表达23例（57．5％）。Egr-1基因表达与Fos、Jun癌基因蛋白的表达无关。食管癌放疗后癌组织Egr-1超表达病人预后较好。结论放疗反应上调食管癌Egr-1表达。Egr-1超表达可作为食管鳞癌放疗反应的基因标志，并对食管鳞状细胞癌的预后判断有重要作用。

EXPRESSION OF EGR-1 GENE AND ITS CORRELATION WITH THE ONCOGENE PROTEINS IN IRRADIATED ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Objective To study the expression of the early growth response gene-1(Egr-1 gene) in irradiated human esophageal cancer tissues,and its relationship with the expressions of Fos,Jun onco-proteins as well as those of Egr-1 target gene proteins P53,Rb and Bax expression.Methods In situ hybridization(ISH) and immunohistochemistry(IHC) were used respectively to detect Egr-1 mRNA,Egr-1,Fos,Jun,P53,Rb and Bax proteins in 80 non-irradiated and irradiated and then surgically resected tumor specimens of esophageal squamous cell carcinoma.Results Egr-1 mRNA and Bax protein were located in the cytoplasm, whereas Egr-1,Fos,Jun,P53 and Rb proteins were located in the nuclei.Egr-1 was expressed in 9 of 40 cases(22.5%) of non-irradiated and 23 of 40 cases(57.5%) of irradiated tumor specimens.No correlation was found between Egr1 gene expression and Fos,Jun onco-protein expressions.Patients who underwent radiotherapy with overexpressed Egr-1 in their cancer tissues had better prognosis.Conclusion Radiotherapy upregulates Egr-1 expression in esophageal carcinoma.Egr-1 overexpression may be a potential gene marker of radiation response and play an important role in the prognosis of esophageal squamous cell carcinoma.