PREFERENTIAL LOSS OF ABNORMAL PROSTATE CARCINOMA-CELLS BY COLLAGENASETREATMENT

Effects of two different methods of tumor disaggregation on flow cytom etric ploidy distribution and intact cell yield were investigated. Eit her mechanical disaggregation or collagenase digestion was applied to 35 prostate tumor specimens. Seven collagenase-treated samples failed to yield any intact cells, whereas with mechanical disaggregation in a ll cases a sufficient number of intact cells were obtained. No differe nces in the FCM ploidy distribution of tumors with a DNA diploid steml ine were observed comparing both techniques. In DNA aneuploid tumors, however, collagenase treatment had an adverse effect on the abnormal c ell populations. In 14/17 of such tumors, the abnormal cell population s were significantly reduced; in eight of these the percentage of DNA aneuploid cells declined even below the minimum percentage (10%) that was defined for DNA aneuploidy. Since collagenase is a widely used enz yme for tissue disaggregation, especially in tumor cytogenetics, the p resented data will have consequences for the interpretation of results obtained by methods involving the use of this enzyme. (C) 1993 Wiley- Liss, Inc.