Correlation of reversion-inducing cysteine-rich protein with kazal motifs (RECK) and extracellular matrix metalloproteinase inducer (EMMPRIN), with MMP-2, MMP-9, and survival in colorectal cancer.

mRNA, and latent and active levels MMP-2 and -9 were higher in tumor tissue compared to normal tissue from 63 patients with colorectal cancer, whereas RECK and EMMPRIN levels were lower. Correlations between mRNA, latent, and active MMP were particular high for MMP-2 in tumor tissue (R(s)=0.6-0.8, P<0.001). For active MMP-2, but not for MMP-9, a significant negative partial correlation (R(p)=-0.440, P<0.001) for RECK was found in tumor tissue, which was confirmed by linear regression analysis. In exploratory survival analyses we found that in patients with localized disease the RECK level in normal or tumor tissue had a significant (P=0.017) association with overall survival.

Plasma levels of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 correlate with disease stage and survival in colorectal cancer patients.

PURPOSE: The matrix metalloproteinases and their inhibitors are known to be involved in the process of tumor invasion and progression. Our objective was to investigate the potential diagnostic and prognostic value of plasma matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 in colorectal cancer. METHODS: Gelatinase bioactivity and immunoreactivity of pro-matrix metalloproteinase-2 and -9, tissue inhibitor of metalloproteinase-1, and carcinoembryonic antigen were determined simultaneously in preoperative plasma and serum of colorectal cancer patients (n = 94) and in healthy controls (n = 51). RESULTS: Plasma pro-matrix metalloproteinase-2 levels were lower in colorectal cancer patients (P < 0.0001) than in controls, and its gelatinolytic activity revealed an inverse correlation with adverse clinicopathologic parameters, such as lymph node involvement (P = 0.017), stage (0, I, II vs. III, IV; P = 0.012), and the carcinoembryonic antigen level (P = 0.016). Pro-matrix metalloproteinase-9 levels did not differ between patients and controls. Pro-matrix metalloproteinase-2 gelatinolytic activity showed potential value in colorectal cancer diagnosis, identifying patients with 70 percent sensitivity at 95 percent specificity. Pro-matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and carcinoembryonic antigen all showed lower sensitivities. Combining pro-matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 measurements increased the sensitivity significantly to 84 percent. With respect to prognosis, tissue inhibitor of metalloproteinase-1 showed value in predicting disease outcome in our patient group, whereas pro-matrix metalloproteinase-2 and -9 did not. The combination of tissue inhibitor of metalloproteinase-1 and carcinoembryonic antigen was better in predicting three-year survival than tissue inhibitor of metalloproteinase-1 alone, but it remains to be determined if the combination would be a better marker for survival than carcinoembryonic antigen alone. CONCLUSIONS: Low pro-matrix metalloproteinase-2 levels and high tissue inhibitor of metalloproteinase-1 levels correlate with parameters of colorectal cancer disease. These correlations may be used in the search for new markers in colorectal cancer diagnosis and prognosis.

Normalization of gene expression measurements in tumor tissues: comparison of 13 endogenous control genes.

For interpretation of quantitative gene expression measurements in clinical tumor samples, a normalizer is necessary to correct expression data for differences in cellular input, RNA quality, and RT efficiency between samples. In many studies, a single housekeeping gene is used for normalization. However, no unequivocal single reference gene (with proven invariable expression between cells) has been identified yet. As the best alternative, the mean expression of multiple housekeeping genes can be used for normalization. In this study, no attempt was made to determine the gold-standard gene for normalization, but to identify the best single housekeeping gene that could accurately replace the measurement of multiple genes. Expression patterns of 13 frequently used housekeeping genes were determined in 80 normal and tumor samples from colorectal, breast, prostate, skin, and bladder tissues with real-time quantitative RT-PCR. These genes included, large ribosomal protein, beta-actin, cyclophilin A, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerokinase 1, beta-2-microglobin, beta-glucuronidase, hypoxanthine ribosyltransferase (HPRT), TATA-box-binding protein, transferrin receptor, porphobilinogen deaminase, ATP synthase 6, and 18S ribosomal RNA. Principal component analysis was used to analyze these expression patterns, independent of the level of expression. Our approach identified HPRT as the single best reference gene that could be used as an accurate and economic alternative for the measurement of multiple housekeeping genes. We recommend this gene for future studies to standardize gene expression measurements in cancer research and tumor diagnostics until a definite gold standard has been determined.