Fig. 4
a Reverse zymography of total protein lysates from osteosarcoma pretreatment biopsies. Equal amounts of protein were loaded on the acrylamide gel supplemented with MMP2 and MMP9. TIMP mediated inhibition of MMP activity was detected as dark bands. Based on their molecular weight TIMP1, TIMP2 and TIMP3 could be identified and are marked by arrows. (P = positive control, N = negative control) (b) Densitometric quantification of TIMP1, TIMP2 and TIMP3. The lower boundary of the box indicates the 25th percentile, and the upper boundary the 75th percentile. The whiskers indicate the highest and lowest values. Medians are indicated. P-values were determined by Mann-Whitney U-test (**p < 0.01, *p < 0.05)