Up-regulation of hypoxia-inducible factor-1 alpha and VEGF mRNAs in peritoneal dissemination of patients with gastric cancer

Abstract

Background: Gastric cancer often metastasizes to the peritoneal cavity in which tumor cells are exposed to hypoxia without systemic circulation. Hypoxia-inducible factor-1 (HIF-1) and its target gene, vascular endothelial growth factor (VEGF), may play a role in the development of peritoneal metastases.

Materials and methods: The mRNA levels of HIF-1 alpha and VEGF were examined in 21 normal gastric mucosa, 158 primary tumors and 18 peritoneal metastases by quantitative RT-PCR.

Results: HIF-1 alpha and VEGF were significantly up-regulated in the peritoneal metastases compared with those of the normal mucosa and the primary tumors. A positive correlation between HIF-1 alpha and VEGF was observed in the peritoneal dissemination.

Conclusion: These results suggest that HIF-1 alpha and its target gene, VEGF, were up-regulated in the intraperitoneal tumors but not in the primary cancers of the stomach. Different microenvironments may influence the expressions of these genes.