Effects of passage, growth phase, and heterogeneity of a tumor cell population on tumor cell chemotaxis.

Recent reports indicate that a wide range of mammalian cells exhibit chemotactic behavior. Unlike the neutrophil, which has been most extensively studied, many of these cells are capable of cell division and passage in vivo and in tissue culture. In this paper we describe studies on the Walker carcinosarcoma 256, a rat mammary tumor which exhibits chemotactic responses to factors in the media of cultured resorbing bone and to a factor generated by proteolysis of the fifth component of serum complement (C5). We demonstrate here that long-term passage in vitro, passage in vivo, the phase of growth, and the heterogeneous nature of this tumor can have a significant effect on the chemotactic behavior of Walker carcinosarcoma cells.