[Interferons in hemato-cancerology].

The anti-tumour effects of interferons (IFNs) in animals and man are well known. However, despite the fact that the three types of human IFNs, leukocyte alpha-IFN, fibroblast beta-IFN and immune gamma-IFN, are available in large amounts through recombinant DNA technology, the practical applicability of IFN therapy in cancer is far from clear. An initial approach to this problem is to determine the mechanism of action of IFNs and, if they do not act, to find out why. There are various ways in which IFN may control tumours, i.e. anti-viral action, inhibition of cell growth, stimulation of cell differentiation, changes in cells modulating the susceptibility to immune rejection, or effects on the host immune systems (natural killer system and cytotoxic proteins). The implications of these data for the use of IFNs in cancer therapy then need to be evaluated. Both alpha- and beta-IFNs may have beneficial effects on growth inhibition and differentiation, but gamma-IFN is probably stronger in boosting the immune recognition and rejection of tumour cells. A combination of these two types of IFNs may give the best results in vivo since they often act synergistically in vitro. The sensitivity of individual tumour cells to the various types of IFN needs to be evaluated to select the best treatment by measuring oncogene mRNA inhibition, G0/G1 arrest and increase in various HLA antigens. Finally, the aim of any treatment (anti-viral action, tumour regression, prevention of metastasis, decreased tumour growth and increased cell differentiation) should be an important consideration in choosing IFN therapy.(ABSTRACT TRUNCATED AT 250 WORDS)