Adenovirus-mediated wt p53 overexpression down-regulates CD40-induced VEGF mRNA expression.

(A) Six hours after adenovirus infection into MM cells, whole cell lysates (15 μg) were subjected to immunoblotting using HRP-conjugated antipantropic p53 (anti-p53-HRP) mAb. Enhanced expression of p53 was observed in RPMI 8226 and SV MM cell lines. Control adenoviruses expressing the β-gal reporter gene (Adβ-gal) were used at the same MOIs as Adwtp53 (MOIs of 800 and 200 for RPMI 8226 and SV cells, respectively). As an additional control, nontransduced MM cells were used as an internal control. (B) MM cells were cultured with control (Adβ-gal) or wt p53 (Adwtp53) adenoviruses in the presence or absence of sCD40L for 48 hours. At the end of treatment, total RNA (5 μg) was subjected to Northern blotting, and an 18S rRNA transcript was used as a loading control. Steady state mRNA expression was quantitated by densitometry of autoradiograms. (■) RPMI 8226; (▪), SV. (C) Adwtp53-transduced MM cells were subjected to transmigration assay in the presence or absence of sCD40L (10 μg/mL [μM]) in the lower chamber of the transwell.