The major focus of these studies has been the study of different regimens of tumor therapeutic intervention on animal model systems. We have developed human xenografts from several lung and pancreatic tumors in BNX mice. Greater than 80% of all pancreatic tumors contain codon 12 mutations in K-ras. We have generated two pancreatic xenograft lines that contain a point mutation in the 12th codon that results in a valine substitution at the cysteine site. Additionally, we have acquired two pancreatic cell lines, CF-PAC1 and CAPAN2 that contain the valine substitution. These lines are being used to do in vitro cell proliferation inhibition studies by antisense oligodeoxynucleotide methylphosphonates directed specifically against the first exon mutation. Additionally radioimmuno-precipitations are being done with p21 antibodies to determine if any proliferation inhibition is associated with specific reduction in p21 caused by incubation with antisense methylphosphonates. Additionally, cell proliferation inhibition studies with K-ras antisense oligodeoxynucleotide in murine lung tumor cell line are being done. Immunogenicity experiments have been performed using several murine lung tumor cell lines in their syngeneic hosts. We have characterized immunization protocols using viable tumor cells followed by surgery to remove subcutaneously growing tumors vs. irradiating cells and using multiple injections to immunize. Surgery and irradiation protocols were evaluated by challenging immunized mice with viable tumor cells injected on the contralateral side. These characterizations were made to identify candidate cell lines for genetic engineering of tumor cells to serve as cancer vaccines against themselves.
