TMZ increases NF-κB transcriptional activity in MMR-proficient but not in MMR-deficient cells. (A) The cells were transiently co-transfected with the pNF-κB-Luc and pRL-null vectors, and 24 h later exposed to 50 μM TMZ+10 μM BG or to BG alone. Firefly luciferase activity was determined 48 and 72 h after drug treatment and normalized to that of Renilla luciferase and then to the total amount of protein used in the assays. Data are expressed in terms of fold change (i.e. the ratio between firefly luciferase activity/μg protein detected in TMZ-treated cells and that detected in the corresponding control cells). Values represent the mean of at least four independent experiments performed with duplicate samples. Bars, standard error of the mean (SEM). *p<0.05, according to paired Student’s t test analysis performed comparing firefly luciferase activity/μg protein of TMZ-treated samples with that of the corresponding controls. (B) M10 cells were cultured in the presence of 50 μM TMZ+10 μM BG or BG alone and culture supernatants were collected after 48 and 72 h of incubation. IL-8 and MCP-1 amount in the culture supernatants was then determined by ELISA and expressed in terms of pg protein/106 cells. Values represent the mean of three independent experiments performed with duplicate samples. Bars, SEM. ** p<0.01 and *p<0.05, according to Student’s t test analysis performed comparing the chemokine amount detected in the culture supernatants of TMZ-treated cells with that detected in the culture supernatants of the corresponding controls.