Background & objective: Endothelin, a potent vasoconstrictor peptide, is involved in mitogenesis modulation, apoptosis, angiogenesis, tumor invasion and metastases. Big endothelin-1 (Big ET-1), the stable precursor of endothelin-1, is regarded as a marker of tumor progression and prognosis. This study was to detect the expression of Big ET-1 in gastric cancer patients, and explore its correlations to progression and prognosis of gastric cancer.
Methods: The plasma levels of Big ET-1 in 118 gastric cancer patients and 20 healthy subjects were detected by enzyme-linked immunosorbent assay (ELISA). The expression of Big ET-1 in primary tumor and para-cancerous gastric tissues of the 118 patients was detected by immunohistochemistry.
Results: The plasma level of Big ET-1 was significantly higher in patients with advanced gastric cancer than in patients with early stage gastric cancer and healthy subjects [(5.78+/-1.85) ng/L vs. (3.13+/-1.72) ng/L and (2.46+/-0.59) ng/L, P=0.026, P=0.008]. The plasma level of Big ET-1 was significantly higher in patients with lymph node metastases than in those without [(6.13+/-2.34) ng/L vs. (4.25+/-1.65) ng/L, P=0.006], and significantly higher in stage II, III, IV patients than in stage I patients. During follow-up, patients with high plasma levels of Big ET-1 had higher recurrence rate and lower 2-year survival rate as compared with those with low plasma levels of Big ET-1 (84.6% vs. 60.9%, P=0.034; 38.5% vs. 56.5%,P=0.017). The positive rate of Big ET-1 was significantly higher in stage II,III and IV patients than in stage I patients.
Conclusion: The plasma level of Big ET-1 may play a vital role in the development, invasion and metastasis of gastric cancer, and may be a predictor of tumor disease severity and prognosis.