Figure 4

Regulation of MMP mRNA expression by TNF-α and TGF-β1. a) U251 and U373 cells were successively adjusted to grow in medium without FCS and stimulated with 10 ng/ml TNF-α and TGF-β1 for 48 h, respectively. Control cells were treated with PBS/BSA solution instead. Total RNA was isolated from these cells and MMP expression strength analysed as explained in Figure 1. Shown is one representative experiment out of six. b) Densitometric quantification of MMP mRNA regulation by TNF-α (light grey columns) and TGF-β1 (dark grey columns), respectively, from the above experiment in arbitrary units. Each value was normalized to the respective GAPDH mRNA expression. Shown are the means of six independent experiments. The standard errors of the mean (SE) are shown as error-bars. Asterisks indicate statistically significant (two-tailed t-test, p ≤ 0.05) alterations compared to the untreated control (white columns).