Objective: To investigate the expression of secreted frizzled-related protein 1 (SFRP1), β-catenin and E-cadherin in colorectal carcinoma and its clinicopathological significance.
Methods: The expression of SFRP1, β-catenin and E-cadherin mRNA and protein in tumor and pericancerous tissue samples from 60 cases of colorectal cancer was assayed by reverse-transcription PCR and immunohistochemistry, respectively. The correlation of their expression with clinicopathological factors of colorectal cancer was analyzed.
Results: In 52/60 cases the relative mRNA expression of SFRP1 in cancer tissue and pericancerous tissue was 0.4837±0.1532 and 0.7170 ±0.1830; for β-catenin was 0.9293± 0.3705 and 0.6469±0.3166; and for E-cadherin was 0.5556±0.2535 and 0.9422±0.2372 (P<0.01), respectively. SFRP1 mRNA expression was associated with lymphatic metastasis (P<0.05). The positive rate of SFRP1 in colorectal cancer was 31.67% (19/60), and was significantly lower than that in pericancerous colorectal mucosa (75.00%, 45/60). No relationship between SFRP1 protein expression and clinical pathology was found. Abnormal expression rates of β-catenin and E-cadherin in colorectal cancer were 75.00% (45/60) and 58.33% (35/60), respectively, which were significantly higher than that in pericancerous colorectal mucosa (1.67% and 6.67%), respectively. Abnormal β-catenin and E-cadherin expression was associated with tumor differentiation, lymphatic metastasis and Duke's staging. SFRP1 protein expression was negatively correlated with β-catenin and E-cadherin expression (r=-0.517, -0.442, Ps<0.01).
Conclusion: Down-regulation of SFRP1 in colorectal cancer may cause abnormal Wnt signaling and induce abnormal β-catenin and E-cadherin expression, indicating that SFRP1 might be involved in the development and progression of colorectal cancer, and could be a novel therapeutic target for colorectal cancer.