Relationship between Egr-1 gene expression and apoptosis in esophageal carcinoma and precancerous lesions.

AIM

To study the expression of early growth response gene-1 (Egr-1 gene) and Bcl-X/(L) protein and its relationship with the cell apoptosis in human esophageal carcinoma (EC) and precancerous lesions.

METHODS

In situ hybridization(ISH), immunohistochemistry (IHC) and TUNEL method were used respectively to detect Egr-1mRNA, Egr-1 protein, apoptosis related-protein Bcl-X/(L) and cell apoptosis in situ from 66 cases of esophageal squamous cell carcinoma and their upper cut edge and paracancerous mucosa.

RESULTS

Egr-1 gene in situ hybridization, Bcl-X/(L) immunohistochemistry positive products were located in the cytoplasm, while Egr-1 immunohistochemistry and TUNEL positive signal were located in the nuclei. The apoptosis index(AI) and the frequency of apoptosis occurrence were increased gradually from precancerous lesion to cancer (P<0.01) and the expression of Egr-1mRNA and Egr-1 protein in dysplasia was the highest among all specimens (P<0.01). The AI of Egr-1 positive cancer tissues was much higher than that of Egr-1 negative cancer tissues (P<0.01), while the AI of Bcl-X/(L) positive cancer tissues was much lower than that of Bcl-X/(L) negative cancer tissues (P<0.01). The AI and Egr-1 expression were not correlated with invasiveness and lymphatic metastasis in EC.

CONCLUSION

Cell apoptosis was present through esophageal carcinogenesis. The expression of Egr-1 mRNA and Egr-1 protein were high in precancerous lesion of esophagus. The AI was increased significantly in Egr-1 positive squamous cell carcinoma. Egr-1 might promote apoptotic effect. Egr-1 expression and cell apoptosis may have an important biological significance in esophageal carcinogenesis.