Relationship of angiogenic and apoptotic activities in soft-tissue sarcoma

Angiogenesis and apoptosis play an essential role in tumor development and progression. Previous studies on apoptosis and angiogenesis of soft-tissue sarcoma (STS) were done separately. This is the first study of the relationship between apoptotic and angiogenic activity. Correlation of expression of anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (Bax) in the tumor cells (TCs) with their expression in endothelial cell (EC) of the tumor blood vessels in STS were also carried out.

101 cases of STS; consisting liposarcoma, malignant fibrous histiocytoma, synovial sarcoma, fibrosarcoma, leiomyosarcoma, rhabdomyosarcoma and malignant peripheral nerve sheath tumor; were collected and immunohistochemical reaction of vascular endothelial growth factor (VEGF), Bcl-2 and Bax were examined.

Higher Bax expression in TCs (54.5%) was seen compared to Bcl-2 expression (44.6%). There was a significant association between Bcl-2 and Bax in TCs with ECs. Significant association was also seen between histological types of STS with Bcl-2 expression; however not with Bax expression. There was an association between VEGF and Bax with high VEGF expression and weak Bax expression. However, VEGF expression was not associated with Bcl-2 expression and histological types.

This study supports the role of ECs of tumor blood vessels and apoptosis of TCs in tumor management. Increased angiogenesis may inhibit apoptosis of TCs and lead to tumor growth. Therefore, inhibition of ECs survival or activation of ECs death is promising prospect for tumor therapy. Immunohistochemical antibodies in this study might be potential useful marker for the prognosis of STS.