Overexpression level of stromelysin 3 is related to the lymph node involvement in non-small cell lung cancer

Proteases contribute to tumor invasion and metastasis via their potential t o degrade basement membranes and extracellular matrix. Our aim was to compa re the level of several proteases: urokinase-type plasminogen activator (u- PA), matrix metalloproteinase 2 (MMP-2; 72-kDa type IV collagenase, also kn own as gelatinase A), MMP-11 [also known as stromelysin 3 (STR3)], and cath epsins B and L in resected non-small cell lung cancer. Between June 1996 an d March 1998, samples of lung tumor tissues were taken from 119 surgically treated patients, Thirty out of the 119 tumor samples were matched with cor responding adjacent normal tissue. u-PA was measured by a commercially avai lable immunoluminometric assay. Metalloproteinases and cathepsins have been evaluated at the RNA level by Northern blot and quantified with a Phosphor Imager, Expression of these proteases was compared to the following clinico pathological parameters: pathological diagnosis, tumor size, exposure to as bestos, radiotherapy, neo-adjuvant chemotherapy, tumornode-metastasis stage , lymph node involvement, presence of metastasis. u-PA, MMP-2, MMP-11/STR3, and cathepsin B were significantly increased in tumor (the tumor:normal ra tio was on average increased by 5.4-, 2.2-, 83.5-, and 2.2-fold, respective ly), The tumor:normal ratio of MMP-11/ STR3 was found to be significantly l inked to the lymph node involvement (P < 0.05). Our results suggest that se veral proteases are involved in the invasive potential of non-small cell lu ng cancer and that the quantification of MMP-11/ STR3 could represent an us eful prognostic marker.