CAN IMMUNOTHERAPY BY GENE-TRANSFER TIP THE BALANCE AGAINST COLORECTAL-CANCER

Gene therapy, in particular the transfer of genes encoding immunostimu latory molecules (cytokines and costimulatory molecules) as well as se lectively cytotoxic enzymes and DNA vaccination, has the potential of enhancing cell mediated immune responses against rumours including tho se of colorectal origin. Genes can be transferred using viral vectors either to cultured tumour cells in vitro that can be returned to the p atient as a ''cancer vaccine'', or directly to tumour cells in vivo. V accination with DNA constructs expressing specific tumour antigens cha racteristic of colorectal neoplasia can trigger immune recognition and destruction of tumour cells. The aim is to tip the balance from protu mour to antitumour mechanisms by generating a local immune response an d systemic antitumour immune memory to destroy metastases. Studies in murine models, combined with human studies, show that such approaches could become an adjunct to current treatments for human colorectal can cer in the near future.