Cytokine gene therapy: hopes and pitfalls

Transduction of a cytokine gene into neoplastic cells elicits a strong inflammatory host reaction that impairs tumor growth, and a long-lasting immune memory is established following their rejection. These findings have aroused great enthusiasm and expectations. Despite their enhanced immunogenicity, however, the immune reaction provoked by repeated injections of these engineered cells can do little more than inhibit the growth of initial tumors and metastases and is only minimally effective against established forms. Better therapeutic activity is thus being sought by combining such cells with tumor cells engineered with other genes.