Activity of type IV collagenases (MMP-2 and MMP-9) in primary pulmonary carcinomas: a quantitative analysis.

PURPOSE: Matrix metalloproteinases MMP-2 and MMP-9 are implicated in invasion and metastasis of malignant tumors. We investigated the expression and activation of MMP-2 and MMP-9 in lung cancer compared with normal lung parenchyma, and looked for a potential marker of malignancy. METHODS: Thirty-six pulmonary carcinomas and paired normal lung specimens were analyzed by gelatin zymography and computer-assisted image analysis for the expression of MMP-2 and MMP-9. RESULTS: We showed that expression of both type IV collagenases was remarkably higher in carcinoma samples than in lung parenchyma. The MMP-9 levels in lung cancer were over twofold higher than in normal lung tissues. The levels of latent and active forms of MMP-2 in lung cancer samples were, correspondingly, 3.8- and 17-fold higher than in lung parenchyma. The tumor/normal (T/N) ratios of MMP-2 were negatively correlated with the hemoglobin levels and erythrocytes number. CONCLUSIONS: A high level of the active form of MMP-2 in almost all of the carcinomas and the near lack of its activation in normal lung parenchyma shows that MMP-2 activation is associated with the malignant phenotype and may serve as a good marker of malignancy. The correlation between low hemoglobin level and T/N ratio of MMP-2 may indicate significance of MMP-2 for angiogenesis.

Enhanced lipid peroxidation in cancer tissue homogenates in non-small cell lung cancer.

The oxidative modification of nucleic acids by reactive oxygen species may lead to malignant conversion, but its exact role in lung cancer biology is still not clear. Lipid peroxidation, a well-known index of free radicals activity, is a process of oxidative polyunsaturated acids destruction. Our study was aimed to investigate the level of lipid peroxidation ex vivo in tumor tissue and lung parenchyma obtained from patients with non-small cell lung cancer. Thirty-two patients with lung cancer (including 19 with squamous cell lung cancer) were enrolled in the study. During a surgical resection, tumor tissue and lung parenchyma were obtained and the concentration of lipid peroxidation products, i.e. conjugated dienes and lipid hydroperoxides, measured. In the whole group of patients the concentrations of conjugated dienes and lipid hydroperoxides in the tumor tissue were higher than those in lung parenchyma (1.008 +/- 0.503 A233 nm vs. 0.717 +/- 0.283 A233 nm; p < 0.05 and 0.109 +/- 0.062 A532 nm vs. 0.102 +/- 0.087 A532 nm; p < 0.05, respectively). Similar results were obtained in squamous cell carcinoma patients (0.975 +/- 0.348 A233 nm vs. 0.708 +/- 0.300 A233 nm; p > 0.02 and 0.094 +/- 0.029 A532 nm vs. 0.080 +/- 0.071 A532 nm; p < 0.05, respectively). In both groups of patients, a positive correlation between concentration of conjugated dienes in tumor tissue and clinical stage (R = 0.45; R = 0.52; p < 0.05, respectively) was found. Our results confirm the enhanced lipid peroxidation in cancer tissue as compared with matched lung parenchyma. Additionally, a higher level of oxidative stress, expressed as the concentration of conjugated dienes in tumor tissue, was associated with clinical progression of the tumor.

Comparison of hydrogen peroxide generation and the content of lipid peroxidation products in lung cancer tissue and pulmonary parenchyma.

Lipid peroxidation, as a well-known index of reactive oxygen species activity, not only in lung biochemistry, is an oxidative process associated with membrane lipid destruction. Also, the oxidative modification of nucleic acids by reactive oxygen species is of remarkable biological importance as it may contribute to malignant conversion, but its exact role in lung cancer biology is still not clear. Our study aimed to investigate the level of lipid peroxidation ex vivo in tumour tissue and lung parenchyma obtained from patients with lung cancer. Forty-two patients with lung cancer were enrolled into the study. During a surgical resection, tumour tissue and lung parenchyma were obtained and concentration of lipid peroxidation products, thiobarbituric acid-reactive substances and Schiff bases, and spontaneous generation of hydrogen peroxide, were measured. The concentration of thiobarbituric acid-reactive substances (P<0.001) in the tumour tissue was higher than that in lung parenchyma. In small cell lung cancer as well as in squamous cell carcinoma patients, a positive correlation between spontaneous generation of hydrogen peroxide in tumour tissue and clinical stage (r = 0.43; r = 0.46; respectively) was found. Our results prove enhanced lipid peroxidation in cancer tissue as compared with matched-lung parenchyma. In small cell lung cancer and squamous cell carcinoma patients, the high level of oxidative stress, expressed as a spontaneous generation of hydrogen peroxide in tumour tissue, was associated with clinical progression of tumour's stage.