Aim: To investigate semaphorin 4D (Sema4D) and hypoxia-inducible factor-1α (HIF-1α) expression in colorectal carcinoma and evaluate their clinicopathological and prognostic significance.
Methods: Eighty-six curatively resected colorectal carcinoma patients at different stages of disease were randomly selected from the group of patients who underwent surgery, and none of them received preoperative radiochemotherapy. Normal proximal adjacent bowel tissue, which served as an internal control, was obtained from 52 randomly selected patients. Immunohistochemistry was performed to analyze the expression of Sema4D and the tumor angiogenesis-related protein HIF-1α in normal colorectal tissues and colorectal carcinoma tissues. The relationships between the expression and clinical characters and prognosis were analyzed.
Results: HIF-1α and Sema4D were positively expressed in 58% and 60% of colorectal carcinoma tissues, respectively. Significantly lower expression levels were observed in normal mucosa (8% and 12%, respectively). HIF-1α and Sema4D expression was closely correlated with histological tumor type, tumor-node-metastasis (TNM) stage, and lymphatic metastasis (P<0.05), but not with age or tumor size (P>0.05). HIF-1α and Sema4D protein expression was significantly correlated with prognosis of colorectal carcinoma, as determined by Spearman rank correlation analysis (r=0.567; P<0.01). Multivariate Cox analysis revealed that only Sema4D expression played a significant role in predicting patient prognosis (P<0.05).
Conclusion: These findings suggest that HIF-1α and Sema4D expression correlates with histological tumor type, TNM stage, and lymphatic metastasis in colorectal carcinoma and that Sema4D is a prognostic indicator of colorectal carcinoma.
Keywords: Colorectal carcinoma; Hypoxia-inducible factor-1α; Immunohistochemical staining; Prognosis; Semaphorin 4D.