RESUMEN
Introduction: The development of oesophageal carcinoma has been attributed to various environmental factors and its incidence varies regionally. The development of this disease is known to occur in recognized histological stages from normal through dysplasia to the malignant stage. Like other cancers; the diagnosis of oesophageal cancer in its premalignant stage would improve the survival. The diagnosis of this cancer on cytomorphology alone is usually done in the late stage of the disease. To be able to diagnose this disease in its early stage; specific tumour markers must be found. The objective of this study was to evaluate p53 tumour suppressor gene protein expression; Epstein-Barr virus latent membrane protein expression and cyclin DI cell cyase protein expression in malignant and normal oesophageal tissues to see whether any variation in their expression in these tissues could be of diagnostic or prognostic value. Methods: 26 archival formalin-fixed paraffin wax embedded tissue blocks of oesphageal carcinoma and 6 of normal oesophagus obtained by endoscopy were studied. 5?m thick tissue sections were cut onto poly-L-Lysine coated microscope slides and dried at 600C for 60 minutes. p53 gene protein expression; EBV-LMPI protein expression and cyclin DI expression were studied immunohisto chemically in these tissue sections. Sections were dewaxed and hydrated to Tris-buffered saline; pH 7.6. Appropriately diluted primary antibodies to p53; EBV-LMPI and Cyclin DI were applied to different sections and incubated overnight at 40OC in a humidity chamber. Sequential applications of other reagents in a three-stage peroxidase antiperoxidase method were applied for chromogen immunoreaction for light microscope visualization. The sections from normal oesophageal tissues were processed with carcinomatous tissues.Results: p53 gene protein was overexpressed in 17 of 26 cases of carcinoma; EBV-LMPI was expressed in 12 of 26 cases of carcinoma; cyclin DI protein was expressed in 14 of the 26 cases of carcinoma; 10 cases of p53 expression were also associated with EBV-LMPI protein expression; 7 cases of p53 protein overexpression did not express EBV-LMPI; 2 cases of EBV-LMPI protein expression did not express p53 protein and 7 cases did not express both p53 and EBV-LMPI proteins. Conclusion: Overexpression of p53 tumour suppressor gene protein in tumour cells of 17 of 26 cases of oesophageal carcinoma while no such expression was demonstrated in normal oesophagus; may have diagnostic and prognostic value. EBV-LMPI expression in tumour cells of 10 of 26 cases of oesophageal carcinoma may also be of value in diagnosis and pathogenesis. Cyclin DI was overexpressed in 14 of the 26 cases and may have diagnostic and prognostic value