Published online Dec 15, 2003. doi: 10.3748/wjg.v9.i12.2866
Revised: April 16, 2003
Accepted: May 21, 2003
Published online: December 15, 2003
AIM: Angiogenesis is an important step in the growth of solid malignant tumors. A number of angiogenic factors have been found such as transforming growth factorβ1 (TGF-β1) and vascular endothelial growth factor (VEGF). However, the roles of TGFβ1 and VEGF in gastrointestinal carcinogenesis are still unclear. This study was to investigate the expressions of TGF-β1 and VEGF in gastrointestinal tract malignant tumors, as well as their association with microvessel density (MVD). At the same time, we also observed the localization of TGF-β1 and its receptor CD105 in gastric malignant tumors.
METHODS: The expressions of TGF-β1 and CD105 were detected in 55 fresh specimens of gastric carcinoma and VEGF and CD105 in 44 fresh specimens of colorectal carcinoma by immunohistochemical staining (S-ABC). TGF-β1 and CD105 in 55 gastric carcinoma tissues on the same slide were detected by using double-stain Immunohistochemistry (DS-ABC).
RESULTS: Among the 55 cases of gastric carcinoma tissues, 30 were positive for TGF-β1 (54.55%). The MVD of TGF-β1 strong positive group (++~+++ 23.22 ± 5.8) was significantly higher than that of weak positive group (+17.56 ± 7.2) and negative group (-17.46 ± 3.9) (q = 4.5, q = 5.3207, respectively, P < 0.01). In the areas of high expression of TGF-β1, MVD and the expression of CD105 were also high. Among the 44 cases of colonic carcinoma tissues, 26 were positive for VEGF (59.1%). The expressions of both VEGF and CD105 (MVD) were related with the depth of invasion (F = 5.438, P < 0.05; F = 4.168, P = 0.05), lymph node metastasis (F = 10.311, P < 0.01; F = 20.282, P < 0.01) and Dukes stage (F = 6.196, P < 0.01; F = 10.274, P < 0.01), but not with histological grade (F = 0.487, P > 0.05). There was a significant correlation between the expression of VEGF and CD105 (MVD) (r = 0.720, P < 0.01).
CONCLUSION: Over-expression of TGF-β1 and VEGF acts as stimulating factors of angiogenesis in gastrointestinal tumors. CD105, as a receptor of TGF-β1, can regulate the biological effect of TGF-β1 in tumor angiogenesis. MVD marked by CD105 is more suitable for detecting newborn blood vessels.