Cancer immunotherapy is an approach that has been widely
investigated in different types of tumor,
the goal. of which is to stimulate host immune response against the cancer cells.
Because of its well established immunomodulating activities in
stimulating the growth and the activation of T cells as well as
natural killer (NK) cells, recombinant interleukin (IL)-2 was
first tested in patients for this purpose. A severe limitation of
such treatment in patients is the toxicity associated with high
doses of systemic recombinant IL-2 administration. Cytokine
secretion in the vicinity of the tumor can potentially minimize
the toxicity associated with systemic cytokine administration,
which could be achieved by the transfer and expression of
various cytokine genes directly in the tumor cells