SPONTANEOUS EVOLUTION OF CYTOPLASMIC LECTIN BINDING AND NUCLEAR SIZE AND DEOXYRIBONUCLEIC-ACID CONTENT IN HUMAN COLORECTAL CANCERS GRAFTED ONTO NUDE-MICE

BACKGROUND: The development of certain biologic characteristics in hum an colorectal tumor xenografted onto nude mice are described with resp ect to their precocious passages, i.e., passaging below 10 onto athymi c mice. EXPERIMENTAL DESIGN: The biologic characteristic monitoring in volved the determination of modifications occurring in cytoplasmic lec tin binding and spontaneous development in nuclear size and DNA conten t. The lectin immunohistochemistry included the characterization of st aining modifications in the glandular parts of the colorectal xenograf ts of wheat germ, Dolichos biflorus, peanut, Solanum tuberosum and Ule x europaeus I agglutinins. The nuclear modifications were monitored by means of the digital cell image analyses of Feulge-stained nuclei. RE SULTS: The results show that although the xenografted human colorectal lines may be relatively stable according to their macroscopic growth over serial passaging, certain of their microscopic characteristics de velop markedly. Three lectins, i.e., wheat germ agglutinin, Solanum tu berosum, and Ulex europaeus I, showed a glandular binding which remain ed relatively stable over serial passaging, whereas the peanut binding exhibited some variations and the DBA binding progressively disappear ed. These cytoplasmic modifications occurring over time were less pron ounced than those that occurred with respect to nuclear measurements, i. e., size and DNA content. CONCLUSIONS: Nuclear DNA content heteroge neity as revealed by DNA histogram typing rather than by DNA index ass essments increased markedly in the colorectal xenografts over their se rial passaging on nude mice.