RESUMEN
<p><b>OBJECTIVE</b>To observe Notch1 expression in esophageal squamous cell carcinoma (ESCC) and investigate its relation with microvascular angiogenesis in the tumor.</p><p><b>METHODS</b>Tissue slices of 40 cases ESCC (cancer group) and 8 cases normal esophagus tissues (normal group) were obtained to analyze the expression of Notch1 and vascular endothelial growth factor (VEGF) using immunohistochemistry and estimate the microvessel density (MVD) in the tumor.</p><p><b>RESULTS</b>Notch1 expression was significantly lower in the cancer group than in the normal group (P<0.05). In the cancer group, Notch1 expression was higher in highly differentiated than in poorly differentiated tumors (P<0.05) regardless of tumor infiltration or lymph nodes metastasis (P>0.05). VEGF expression and MVD were significantly higher in cancer group than in normal group, and showed significant differences between tumors with different differentiation degrees, infiltration and lymph node metastasis (P<0.05). Correlation analysis showed that Notch1 expression was inversely correlated to VEGF expression.</p><p><b>CONCLUSION</b>Notch1 may be an anti-oncogene in ESCC and affects cell differentiation in early stage of the malignancy. Abnormally low expression of Notch1 in ESCC may be one of the upstream factors to induce high expression of VEGF and increased MVD. The Notch1 pathway might play a key role in microvascular angiogenesis in ESCC.</p>