% Survival 
Irradiated PA-1 cells were assayed for their ability to prolong animal survival in mice 
with preexisting tumor burden. PA-1 cells were transduced with the STK retroviral 
vector. The same experimental design was used as with the HCT-STK cells described 
in figure 26. Figure 27 demonstrates that PA-1-STK cells will also prolong the survival 
of mice with a preexisting kbalb intraperitoneal tumor. Figure 28 shows the results of a 
a combination of results obtained in figure 26 and 27 and a repeat experiment using 
PA- 1- STK cells. 
27 
Immunization studies 
28 
A future goal of this protocol is for the patient to be immunized against their ovarian 
tumor. This may be possible in two ways, ,-irst, the killing effect of TK positive cells on 
TK negative cells may generate an immune response to the patient’s own ovarian 
carcinoma. Second, one of us (C M.) is studying the use of adjuvants on the ability to 
vaccinate colon carcinoma patients to their tumor by using an allogeneic tumor cell 
vaccine in conjunction with IL-1 beta. Therefore, in the future, adjuvants may be a 
possible method added to this protocol to increase the ability of the dying irradiated TK 
positive tumor cells to also function as a vaccine. 
To study the effect of killing STK transduced cells in vivo mice were subcutaneously 
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Recombinant DNA Research, Volume 15 
