Assessment of vascular endothelial growth factor and carbonic anhydrase-IX expression in rectal cancer

Abstract

Objective To explore the expressions and role of carbonic anhydrases-Ⅸ (CA-Ⅸ) and vascular endothelial growth factor (VEGF) in rectal cancer. Methods The expression levels of CA-Ⅸ and VEGF in 104 pathologically diagnosed rectal cancer tissues, 30 normal tissues, and 30 cases of non-neoplastic rectal mucosa were detected by Western blotting. Results The overall positive expression rate of CA-Ⅸ and VEGF in rectal cancer was 72.1% and 65.4%, repeetively, which was higher than that in non-neoplastic tissue(P<0.05). The expression of CA-Ⅸ was related to Dukes' stage and status of lymph node metastasis. CA-Ⅸ expression positive rate was decreased with the progression of the Dukes' stage from A to C. CA-Ⅸ expression in patients with lymph node negative involvement was higher than that in lymph node involvement, 85.2% vs 58.8%, 56.3%, respectly, with the difference being statistically significant,P<0.05. The expression of VEGF was related to status of lymph node metastasis. VEGF expression in carcinoma tissues of patients with lymph node involvement (81.3%) was significandy higher than that in lymph node negative involvement (53.7%) ,X~2=6.88, P<0.05, and VEGF expression in mesorectal tissues with lymph node involvement (75.0%) was significantly higher than that in lymph node negative involvement (25.9%),X~2=14.52, P<0.05. There was no positive association between CA-Ⅸ and VEGF. Conclusion The hypoxia and angiogenesis are helpful to the judgment of prognosis. Key words: Rectal carcinoma; Hypoxia; Vascular endothelial growth factor; Carbonic anhydrase-9