KAI1 gene is differently expressed in papillary and pancreatic cancer:influence on metastasis

AIM To compare KAI1 in cancer of papilla ofVater and pancreas to evaluate whether there aredifferences in biologic behavior which mightaccount for prognosis.METHODS We compared the expression in 24papillay and 29 pancreatic cancers usingNorthern blot analysis,immunochemical assayand in situ hybridization,and investigatedwhether early diagnosis or molecular differencespredict the outcome in these tumor entities.RESULTS By Northern blot analysis there is nostatistical difference of KAI1 levels in normaland cancerous papilla.No association betweenKAI1 mRNA expression and tumor stage or tumordifferentiation was found in the tumors.Byimmunohistochemical assay,KAI1 staining incytoplasm of papillary cancer cells was similarto that of normal papillary cells.By in situhybridization,the results of KAI1 mRNAexpression in normal and cancerous papilla weresimilar to those with immunohistochemicalassay.The normal and cancerous pancreastissues were also analyzed by the methods usedin papillary samples.CONCLUSION Although the biologic roles of KAI1 have not been clarified, our results suggest that KAI1 may restrict the progression of malignant papillary cancer, but its expression might not have any effect on the characteristics of papillary tumor, whereas by the analysis of KAl1 gene, its reduced expression is closely related to the progression and metastases of pancreatic cancer.