EFFECT OF INTERLEUKIN-2 ON THE PROLIFERAT ION OF 2 INTESTINAL-CELL LINES AND ON THE EXPRESSION OF TGF-BETA, JUN AND FOS GENES

Effect of interleukin 2 (IL-2) on the proliferative rate of a human co lon adenocarcinoma line (HT-29 D4) and of an untransformed rat intesti nal cell clone (IEC-6) was studied in vitro. IL-2 had an antiprolifera tive effect which was cytotoxic-free: interleukin 2 did not induce any significant cell death, apoptosis or change in cellular protein conte nt. Northern blot characterization of cellular mRNA revealed that inte rleukin 2 enhances the expression of JUN, FOS and TGF beta which are k nown to be involved in antiproliferative processes. Kinetic analyses s uggest that the aforedescribed biological effect is mediated by the AP I complex (JUN/FOS) when dealing with rapid inhibition (HT-29 D4 and I EC-6) and by an autocrin TGF beta loop when dealing with slow inhibiti on (IEC-6).