Cytokines in the treatment of malignancies.

Cytokines are pleiotropic peptides produced by lymphoid cells that play important roles in cellular proliferation and multiplication. Diminished or enhanced production or constitutive secretion of cytokines contributes to the aetiology and pathogenesis of several diseases. They are soluble mediators eliciting specific responses of different target cells of paracrine, autocrine and cascade systems of the organism. Their secretion is regulated at the molecular genetic level. Gene rearrangements of cytokines and their receptors have been demonstrated in several diseases. As means of specific or supportive therapy, cytokine treatment has been used both in neoplastic and other proliferative diseases. Lymphokines and interferons comprise the first, whereas colony stimulating factors and growth factors yield the second group of cytokines. Most scientific experience is with interferon-alpha. Its anti-viral mechanism of action has been extensively studied and clarified, whereas its antitumour effect is more obscure and is a result of many simultaneous biologic events.