IL-6 induced the cytoplasmic accumulation of p27^Kip1 and p53 proteins and blocked the expression of Fas ligand, p27^Kip1, p21^Cip1/Waf1, and bax genes in NOP2. In serum-free media, NOP2 cultured with or without IL-6 (2 ng/mL) for 24 hours (A) or for 12 hours (B) was harvested and cellular RNA was isolated. Subsequent real-time PCR analysis using cDNA synthesized from total RNA evaluated quantitatively the expression of Fas ligand, p27^Kip1 (A), p21^Cip1/Waf1, and bax (B) genes. The expression of Fas ligand, p27^Kip1, p21^Cip1/Waf1, and bax genes was blocked by IL-6 treatment in NOP2. Values of relative gene expressions are indicated by the ratio to glyceraldehyde-3-phosphate dehydrogenase (G3PDH) when the value of time 0 was 1. The values are indicated by the means and SDs obtained from 2 independent experiments. Differences of relative gene expression between cells cultured without and with IL-6 were all statistically significant (P < .01). (C) Western blot showed that both p27^Kip1 and p53 proteins remained in the cytoplasm of NOP2 treated with IL-6. Cytoplasmic (indicated as C) and nuclear (indicated as N) extracts were probed with an anti-p53 antibody in Western blot analysis. Values of the relative amounts of proteins were determined as densities of bands by Scion image software (Scion, Frederick, MA) and shown as a ratio to time 0.