Egr-1基因及其相关癌基因蛋白在放疗后食管鳞癌的表达

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

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、C-fos、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例非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。

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 4O cases （57.5%） of irradiated tumor specimens. No correlation was found between Egr-1 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.