Lysosomal enzyme activity in liver tissue, kidney tissue, and tumor tissue from patients with renal carcinoma

In a consecutive series of 17 patients with renal carcinoma, the free and total activities of acid phosphatase, aryl sulfatase, cathepsin, and β-glucuronidase were determined in liver tissue, kidney tissue, and in renal carcinoma tissue. The total activities of the enzymes were significantly increased in liver tissue as compared with the corresponding activities in liver tissue from controls. In kidney tissue without tumor growth, the lysosomal enzyme activities were of the same order of magnitude as in normal liver tissue. The enzyme activities in renal carcinoma tissue were lower than in liver and in kidney tissue. The ratios between total and free enzyme activities were significantly lower in the central part than in the peripheral part of the tumors. In most cases, areas with necrosis of different sizes were found in the central parts of the tumors. A significant positive correlation between the free activity of lysosomal enzymes in tumor tissue and the total activities of the same enzymes in liver tissue was demonstrated. The findings might be a support for the hypothesis that lysosomal enzymes are released from tumor tissue and then taken up by other tissues and there keep their activity.