QUANTIFICATION OF MATRIX METALLOPROTEINASES AND TISSUE INHIBITORS OF METALLOPROTEINASE IN PROSTATIC TISSUE - ANALYTICAL ASPECTS

BACKGROUND. The balance between matrix metalloproteinases (MMP) and th e tissue inhibitors of metalloproteinases (TIMP) has been seen as impo rtant during tumor invasion and progression. The determination of thes e components needs a special strategy of tissue preparation. This anal ytical problem has not been considered for prostatic tissue. METHODS. We adapted an extraction method consisting of two extraction steps wit h 0.25% Triton X-100/CaCl2 solution and two heat extraction steps at 6 0 degrees C for 4 min. This combination allowed a complete extraction of MMP (measured as enzyme activity) and TIMP-1 (measured with an ELIS A test) from cancerous and normal prostatic tissue samples. RESULTS. T he median values for cancerous vs. normal MMPs (50.8 mU/g wet tissue a nd 1,580 mU/g protein vs. 88.8 and 2,497) and TIMP-1 (4.49 mu g/g wet tissue and 96.7 mu g/g protein vs. 12.4 and 237.8) were significantly lower, whereas the respective ratios for MMP/TIMP-1 (11.1 vs. 4.0 on w et weight and 15.5 vs. 5.3 on protein basis) were significantly higher . CONCLUSIONS. An optimized extraction procedure was elaborated for de termining MMPs and TIMP-1 in prostatic tissue samples. The increased r atio of MMP/TIMP-1 can be interpreted as an indicator of the imbalance between MMP and TIMP, characteristic of prostate carcinoma tissue. (C ) 1998 Wiley-Liss, Inc.