Figure 8.

Heat-shocked SMA560 cells show reduced tumorigenicity in immune-competent syngeneic mice. SMA560 cells were heat shocked (42°C, 1 h) or were left untreated. A, After a 24 h recovery, groups of 5 VM/Dk mice were injected with 100,000 cells, either heat shocked or untreated, subcutaneously into the right flanks, and tumor volumes were measured 42 d later. Cells in both groups were of equal viability. p value (t test) between heat-shocked cell tumor growth versus control is shown. In this experiment, the solitary mouse in the control group without tumor later grew one and had to be killed 90 d after tumor inoculation. B, The same heat shock experiment was conducted using immunoincompetent athymic (nu/nu) mice as tumor recipients. Both heat-shocked and non-heat-shocked tumor cells grew in nude mice at statistically indistinguishable rates (p value, not significant), and mice were killed on day 22.