Dose-dependent effects of Dex and IL-6 on p21 and p27 expression in MM cells. Total cell lysates were prepared from OCI-My5 MM cells after 16 hours of culture with Dex (0.01 to 10 μmol/L) or IL-6 (0.10 to 100 ng/mL). Lysates were immunoprecipitated with anti-p21 or anti-p27 polyclonal Abs, followed by Western immunoblotting with anti-p21 or anti-p27 MoAbs.