Zhen-Tao Yu1, Hua-Feng Zhao, Xiao-Bin Shang. 1. Department of Esophageal Neoplasms, Tianjin Medical University Cancer Hospital, Tianjin 300060, China. yuzhtao@hotmail.com
Abstract
OBJECTIVE: To investigate the expression of hypoxia-inducible factor (HIF)-1alpha and vessel endothelial growth factor (VEGF) and their relations with the clinicopathological features of esophageal squamous cancer. METHODS: Esophageal squamous cancer tissues and normal end squamous epithelium tissues were collected from 42 patients during operation. Real-time quantitative PCR was used to detect the mRNA expression of HIF-1alpha and VEGF and immunohistochemistry was used to detect the protein expression of HIF-1alpha and VEGF. The relations between the expression of HIF-1alpha, VEGF and depth of tumor invasion, histological grade, lymphatic invasion, and lymph node metastasis were evaluated. RESULTS: The HIF-1alpha mRNA expression level was 5.88 + 1.12 in the esophageal squamous cancer tissue, higher, but not significantly, than that in normal end squamous epithelium tissue 4.76 +/- 1.26 (P = 0.014). The VEGF mRNA expression level in the esophageal squamous cancer tissue was 12.79 +/- 2.51, higher, but not significantly, than that in the normal end squamous epithelium tissue (10.92 +/- 2.23, P = 0.010). The HIF-1alpha and VEGF protein positive rates in esophageal squamous cancer tissue were 50% (21/42) and 76% (32/42) respectively, significantly higher than those in the normal esophageal tissue [14% (6/42) and 33% (14/42) respectively, P = 0.001, P = 0.000]. The expression of HIF-1alpha mRNA and VEGF mRNA in the esophageal squamous cancer were correlated with lymph node metastasis (including lymphatic invasion) (P = 0.063 and P = 0.073 respectively). HIF-1alpha immunoreactivity was localized in the nucleus and/or cytoplasm of the cancer cells. The expression of HIF-1alpha protein was correlated with lymph node metastasis and histological grade (P = 0.013 and P = 0.028 respectively). No correlation was found between HIF-1alpha mRNA and VEGF protein. CONCLUSION: HIF-1alpha may be regulated at transcription and post-transcription levels in addition to protein level. It also plays an important role in lymphatic metastasis of esophageal squamous cancer and tumor malignancy degree. So HIF-1alpha and VEGF may serve as predictors of progression in esophageal squamous cell carcinoma and as potential targets for anti-angiogenesis therapy of esophageal squamous cell carcinoma.
OBJECTIVE: To investigate the expression of hypoxia-inducible factor (HIF)-1alpha and vessel endothelial growth factor (VEGF) and their relations with the clinicopathological features of esophageal squamous cancer. METHODS:Esophageal squamous cancer tissues and normal end squamous epithelium tissues were collected from 42 patients during operation. Real-time quantitative PCR was used to detect the mRNA expression of HIF-1alpha and VEGF and immunohistochemistry was used to detect the protein expression of HIF-1alpha and VEGF. The relations between the expression of HIF-1alpha, VEGF and depth of tumor invasion, histological grade, lymphatic invasion, and lymph node metastasis were evaluated. RESULTS: The HIF-1alpha mRNA expression level was 5.88 + 1.12 in the esophageal squamous cancer tissue, higher, but not significantly, than that in normal end squamous epithelium tissue 4.76 +/- 1.26 (P = 0.014). The VEGF mRNA expression level in the esophageal squamous cancer tissue was 12.79 +/- 2.51, higher, but not significantly, than that in the normal end squamous epithelium tissue (10.92 +/- 2.23, P = 0.010). The HIF-1alpha and VEGF protein positive rates in esophageal squamous cancer tissue were 50% (21/42) and 76% (32/42) respectively, significantly higher than those in the normal esophageal tissue [14% (6/42) and 33% (14/42) respectively, P = 0.001, P = 0.000]. The expression of HIF-1alpha mRNA and VEGF mRNA in the esophageal squamous cancer were correlated with lymph node metastasis (including lymphatic invasion) (P = 0.063 and P = 0.073 respectively). HIF-1alpha immunoreactivity was localized in the nucleus and/or cytoplasm of the cancer cells. The expression of HIF-1alpha protein was correlated with lymph node metastasis and histological grade (P = 0.013 and P = 0.028 respectively). No correlation was found between HIF-1alpha mRNA and VEGF protein. CONCLUSION:HIF-1alpha may be regulated at transcription and post-transcription levels in addition to protein level. It also plays an important role in lymphatic metastasis of esophageal squamous cancer and tumor malignancy degree. So HIF-1alpha and VEGF may serve as predictors of progression in esophageal squamous cell carcinoma and as potential targets for anti-angiogenesis therapy of esophageal squamous cell carcinoma.