Increased Trypsin Sensitivity of Cell Surface Macromolecules after Malignant Transformation

Abstract

The effect of treatment with 0.04% (w/v) trypsin (EC 3.4.4.4) for 3 h on the electrophoretic mobility (EPM) of polyoma-virus malignantly transformed BHK21 cells (Py6) and their normal counterparts has been investigated. These particular conditions were chosen because an earlier study had shown that such treatment released material from the Py6 cells which was not obtained from the BHK21 cells. The negative EPM of the Py6 cells at pH 7.5 was greatly increased by this treatment; whereas the EPM of the BHK21 cells remained unchanged. Active enzyme was required to produce the change. No evidence was obtained for cytolysis, cytotoxicity or uptake of the enzyme by the treated Py6 cells. Measurement of the EPM of the Py6 cells at different pH levels before and after trypsin treatment suggested that the enzyme was removing cationic groupings from the cell surface.

Differences in the Surface Components of Normal and SV-40 Transformed 3T3 Mouse Fibroblasts

“…Recently, using the BHK21 and polyoma virus-transformed cell system, Latner and Turner (1978) have shown that such extra basic material also occurs in the transformed cells. Similar increases in basic material have also been reported on lymph node cells derived from acute lymphoblastic leukaemia (Cook and Jacobson, 1968).…”