Altered expression of jack fruit lectin specific glycoconjugates in benign and malignant human colorectum

Lectins bind to terminal non reducing sugars of glycoconjugates in cell membranes and secretions. These glycoproteins can be very characteristic, both for the differentiation state of a tissue and for its grade of malignancy. The carbohydrate structures of cellular glycoconjugates in normal, adenoma, and carcinoma of human colorectum were analysed using HRP conjugated Jack Fruit Lectin (JFL). Fifty two rectal carcinomas, 18 adenomas and 25 normal rectal tissues were used for the study. Diaminobenzidine (DAB) was used as the visualant. Normal rectal tissues showed positive reaction with intense staining in more than 60% of the cells. Adenomas were seen to have moderate to intense staining with a range of 30 to 60% positive cells. The lowest levels of JFL staining were observed in invasive tumours. JFL binding was found to decrease with carcinomatous cells compared to adenomas and normal cells. A significant negative association was found between JFL binding and histologic abnormality (r = -0.85, P <0.0000). These results suggest that there are alterations in the carbohydrate structures of cellular glycoconjugates, which can be related to goblet cell differentiation, in normal, benign and malignant human colorectal tissue.