Characteristics of the chemotactic response of neoplastic cells to a factor derived from the fifth component of...

Chemotactic factors for malignant neoplastic cells can be generated from either the fifth component of complement or from leukotactic fractions obtained from zymosanactivated serum. Digestion of the fifth component of complement by trypsin initially produced leukotactic activity, but as digestion continues, leukotactic activity is lost and tumor cell chemotactic activity is generated. Separation of the leukotactic activity is lost and tumor cell chemotactic activity is generated. Separation of the leukotactic activity and tumor cell chemotactic activity can be accomplished by gel filtration or isoelectric focusing. Gel filtration indicates that the tumor cell chemotactic factor has a molecular weight of approximately 8000 daltons. Tumor cell chemotactic activity can be generated by trypsinizing the leukotactic fractions isolated by isoelectric focusing. The responses of cultured Walker tumor cells or of Walker ascites tumor cells are dose-dependent and truly chemotactic. Cells from a murine malignant lymphoma do not respond to the complement-derived chemotactic factor for tumor cells, indicating that not all malignant cells share this functional property.