miR-34a expression correlates with down-regulation of SIRT1.

<p>(<b>A</b>) mRNA levels of SIRT1 and miR-34a were measured by qPCR upon [20 µM] etoposide treatment at indicated time points in D283-MED cells. (<b>B</b>) SIRT1 protein levels upon [20 µM] etoposide treatment were assessed by western blot. Band density was quantified by densitometry analysis. The blot shown is representative of four independent experiments. (<b>C</b>) SIRT1 levels and localisation were detected by immunofluorescence. Quantification was quantified by densitometry analysis (AQM Advance 6 imaging software) (<b>D</b>) D283-MED and MEB-Med8A cells were treated with [100 mM] nicotinamide for indicated time points. The percentage of cell viability was measured by MTS assay and normalised to the untreated control. Data shown are the mean ± S.E.M of three independent experiments. One-way ANOVA followed by Bonferroni test was performed (*indicates p<0.05). (<b>E, F</b>) Dose response of MB cells treated with nicotinamide. Cells were treated with nicotinamide at indicated concentrations and times and cell viability was measured by MTS assay. (<b>E</b>) D283-MED cells and (<b>F</b>) MEB-Med8A cells. Error bars shown are SD of 6 replicates.