A rapid technique for isolation of viable tumor cells from solid tumors: Use of the tumor cells for induction and measurement of cell-mediated cytotoxic responses

A rapid and simple technique for the isolation of viable tumor cells from human and mouse solid neoplasms is described. It consists of a 5 to 10-min treatment with trypsin-collagenase-DNase mixture, followed by mechanical disaggregation of the tumor tissue and subsequently by a brief centrifugation on a discontinuous Percoll gradient. With the tumors employed, this procedure usually requires less than 1 hr and results in preparations comprising greater than 80% tumor cells with viability of 80-90%. Cell-mediated cytotoxic response was measured with: (a) unsensitized lymphocytes freshly obtained from tumor-bearing hosts; (b) lymphocytes propagated in culture with T cell growth factor; and (c) lymphocytes stimulated in cocultures with autologous or syngeneic tumor cells. The cytotoxic activity was assessed in a modified [⁵¹Cr]-release assay adapted for solid tumor cells, allowing a long incubation period (24 hr) and the use of a low number (200-1000) of highly labeled target cells (2-10 counts/min/cell).