Elevated level of circulating matrix metalloproteinase-9 in patients with lung cancer

Respir Med. 2001 Jan;95(1):1-4. doi: 10.1053/rmed.2000.0923.


The 72 kDa matrix metalloproteinase (MMP-2) and the 92 kDa matrix metalloproteinase (MMP-9), are type IV collagenases that have been implicated as important factors in cancer invasion and metastasis formation. We have used quantitative zymography and computer-assisted image analysis to measure the levels of MMP-9 and MMP-2 in 19 samples of serum of lung cancer patients and in 23 samples of normal serum. Mean levels of MMP-9 were significantly elevated in cancer samples compared with normal sera (1.33 +/- 0.61 microU microl(-1) vs. 0.37 +/- 0.10 microU microl(-1), P<0.0001). MMP-2 levels did not differ significantly in these two groups. However, there was no significant correlation between serum MMP-9 activity and the disease stage. We found that circulation levels of MMP-9 in lung cancer patients is 3.6-fold higher than in healthy volunteers, however, we do not consider this elevation to be a direct reflection of MMP-9 over-production by tumour cells.

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor / blood*
  • Carcinoma, Non-Small-Cell Lung / enzymology*
  • Carcinoma, Small Cell / enzymology*
  • Female
  • Humans
  • Lung Neoplasms / enzymology*
  • Male
  • Matrix Metalloproteinase 2 / blood
  • Matrix Metalloproteinase 9 / blood*
  • Middle Aged


  • Biomarkers, Tumor
  • Matrix Metalloproteinase 2
  • Matrix Metalloproteinase 9