Effect of enzymic removal of cell surface constituents on metastatic colonisation potential of mouse mammary tumour cells.

Trypsin treatment of viable cells from 24 spontaneous murine mammary carcinomas resulted in a mild but reproducible diminution in their capability to colonise the lung after i.v. reinoculation but did not alter the distribution of deposits formed. The effects were similar on tumours of high and of low colonisation potentials. Neuraminidase and hyaluronidase did not exert any effect on metastatic colonisation potential, although all 3 enzymes were shown to be active and specific in cleaving their purified substrates, under the conditions in which they were used on the cells. Trypsin and neuraminidase were also shown to release characteristic components from the surfaces of living tumour cells, although hyaluronidase did not release detectable quantities of N-acetyl glucosamine indicating that there is little hyaluronic acid-related mucopolysaccharide on the surface of these mammary tumour cells. The results provide direct evidence suggesting that surface protein composition exerts an effect on the metastatic colonisation capability of mammary tumour cells.