RELATIONSHIP BETWEEN THE LEVELS OF PURINE SALVAGE PATHWAY ENZYMES ANDCLINICAL BIOLOGICAL AGGRESSIVENESS OF HUMAN COLON-CARCINOMA/

A large series of samples obtained after surgical resection of intesti nal mucosa of patients affected by intestinal carcinoma was examined i n order to define possible relationships between levels of enzymes inv olved in the purine salvage pathway and clinical/biological parameters of aggressiveness and invasiveness. The results confirm our previous observation on a different pattern of purine salvage enzymes in tumor as compared to normal colon tissues (Camici et al., 1990). In fact, we observed in human colon tumor tissues a significant enhancement of th e three enzymes involved in the synthesis of IMP, hypoxanthine guanine phosphoribosyltransferase (HGPRT), adenosine deaminase (ADA) and puri ne nucleoside phosphorylase (PNP). On the other hand, no variation was observed in the 5'-nucleotidase and alkaline phosphatase activities. While we could not find a significant correlation between HGPRT, ADA a nd PNP activities and histologic grading or biological parameters of t umor aggressiveness, the significant correlation with the extent of di sease, as expressed by the Dukes' stage, would demonstrate at least fo r human colon tumors, a relationship between enzyme activity and tumor invasiveness.