Selection and in vivo properties of lectin-attachment variants of malignant murine lymphosarcoma cell lines.

Variants of malignant RAW117 lymphosarcoma cell lines were selected by sequential nonadherence to polystyreneImmobilized lectlns. Parental murine lymphosarcoma line RAW117-P grew In suspension and was rapidly bound by Immobilized concanavalin A (Con A), Ricinus communis agglutinin I (RCAI), peanut agglutinin (PNA), or wheat germ agglutinin (WGA). After attachment of most cells to lectin-substituted petri dishes, the unattached cells «1%) were removed by aspiration and subcultured. Selection by nonadherence to Immobilized lectlns was repeated seven to ten times, and the resulting cell lines were tested in BALB/c mice to determine their malignant potentials. Parental line RAW117-P formed few (median, 0; range, 0-20) liver tumor colonies per 5x10' Iv Injected cells after 14 days, whereas a variant line selected ten times on Immobilized Con A (RAW117P Con d'o,) formed a median of 95 (range, 9->200) liver colonies. RAW117-P cells selected by nonadherence on immobilized WGA, PNA, or RCAI showed no increase in liver tumor formation compared to the cells of the parental line. In contrast, RAW117-H10, a variant line selected ten times In vivo for liver colonization, formed more than 200 liver tumor colonies, and selection eight times on Immobilized WGA yielded a line (RAW117-H10 WGA"8) that formed a median of only 1 (range, 0-4) tumor colony. Variants of the RAW117-H10 line selected on Immobilized RCAI, Con A, or PNA still formed more than 200 liver tumor colonies. 1251-labeled lectin-binding studies Indicated decreased lectin-binding sites on the In vivo and some of the immobilized lectin-selected lines. Autoradlographs of '''I-labeled Con A-stained sodium dodecyl sulfate polyacrylamide gels showed a decrease In the major Con A-staining band (mol wt, =70,000) In the in vivo and Immobilized Con A-selected lines. These studies Indicated that alterations In cell surface lectin receptors could modify in vivo malignant behavior.-JNCI 64: