Expression and association of carbonic anhydrase IX and cyclooxygenase-2 in colorectal cancer.

BACKGROUND: This work was designed to determine the relationship between hypoxia-inducible protein carbonic anhydrase IX (CA IX) and pro-inflammatory enzyme cyclooxygenase-2 (COX-2) in patients with colorectal cancer (CRC). METHODS: We examined CA IX and COX-2 expression in CRC tissues by immunohistochemical staining of 111 samples. We evaluated the correlation between the expression of these proteins and their correlation with the clinico-morphological parameters of CRC. RESULTS: CA IX was detected in 89 of 111 cases (80.2%). We predominantly observed membrane staining (70.3%) and a strong immunoreaction intensity (58.6%). The percentage of labeled cells in malignant lesions was less than 25% in 12.6% of cases, less than 50% in 15.3% of cases and more than 50% in 52.3% of CRC cases. The COX-2 protein was expressed in 94 of 111 cases (84.7%). We noticed only cytoplasmic localization, while immunoreaction intensity was predominantly strong (47.8%). The percentage of COX-2 positive cells was less than 25% only in 2.7% of the cases, less than 50% in 21.6% of the cases and more than 50% in 60.4% of the cases. No statistically significant correlations were observed between CA IX expression and clinico-morphological parameters. COX-2 expression was only significantly correlated with the tumor stage. Statistical analysis confirmed a significant correlation between the parameters of expression of the CA IX and COX-2 proteins. CONCLUSION: CA IX/COX-2 interplay can promote hypoxia survival and the invasion of tumor cells. These proteins may represent independent prognostic factors of CRC.

Expression and significance of survivin in colorectal high grade and low grade adenomas.

We examined immunohistochemically the expression pattern of a potential tumor biomarker survivin in a panel of 116 tubular adenomatous polyps to determine its association with clinicomorphological parameters such as age of patients, size of polyps, degree of dysplasia and polyp localization. In each section, the subcellular localization of survivin antigen and the intensity of staining were assessed. Overall, survivin was expressed in 90 cases (77.6%). Cytoplasmic positivity was observed in 46/116 cases (39.7%), while nuclear and combined nuclear and cytoplasmic reaction in 44/116 cases (37.9%). High grade dysplasia was diagnosed in 52 cases (44.8%) and low grade dysplasia in 64 cases (55.2%). Statistical analysis revealed a significant correlation between subcellular survivin localization and the degree of dysplasia, size of polyps and colon localization. On the other hand, survivin expression pattern did not correlate with the age of patients. Statistically significant trend was confirmed between intensity of survivin immunoreaction and tumor size and dysplasia grade, and also the trend between negative/strong survivin intensity and polyp localization. Another statistically significant association was found between the degree of dysplasia and the size of polyps. Our findings revealed that survivin is frequently expressed in different subcellular compartments of adenoma cells. Our recent results suggest that the nuclear and combined nuclear and cytoplasmic survivin localizations are strongly associated with poor prognostic parameters in the assessment of colon adenomas. Thus, survivin may represent a promising biomarker in immunohistochemical evaluation of these lesions.