Expression of Rac1, HIF-1α, and VEGF in gastric carcinoma: correlation with angiogenesis and prognosis.

Background: The aim of this study was to investigate the relationship between the expression of hypoxia-inducible factor-1α (HIF-1α), Ras-related C3 botulinum toxin substrate 1 (Rac1), and vascular endothelial growth factor (VEGF), as well as their correlation with angiogenesis and prognosis in gastric carcinoma.

Material and methods: The expression of Rac1, HIF-1α, VEGF, and CD34 (described in terms of microvessel density, MVD) was determined by immunohistochemical staining of tissues from 60 radically resected gastric cancer specimens.

Results: The proportion of specimens expressing Rac1, HIF-1α, and VEGF was 37/60 (61.7%), 35/60 (58.3%), and 40/60 (66.7%), respectively. The levels of Rac1, HIF-1α, and VEGF expression were significantly correlated with Lauren's classification, lymph node metastasis, and pathologic staging (p < 0.05). There were positive correlations between MVD and the expression of Rac1, HIF-1α, and VEGF. The mean survival time and 5-year survival rate in cases with positive Rac1, HIF-1α, and VEGF expression and MVD ≥ 26.3 were significantly shorter than those with negative Rac1, HIF-1α, and VEGF expression and MVD < 26.3.

Conclusion: Rac1, HIF-1α, and VEGF play an important role in tumor invasion and metastasis, especially in tumor angiogenesis. Thus, testing the expression of Rac1, HIF-1α, and VEGF may be a useful index for treatment and prognosis.