To verify whether KYNA affects cell cycle regulators, the protein expression of cyclin-dependent kinase inhibitor p21 Waf1/Cip1 was investigated in colon adenocarcinoma HT-29 cells exposed to KYNA.
Using p21(WAF1)-deficient cells derived from the HCT116 colon adenocarcinoma cell line, we now show that p21(WAF1) is indeed responsible for the antiproliferative effects of the type II IFN, IFN-gamma.