Significance of Monocyte Chemotactic Protein-1 and Thymidine Phosphorylase in Angiogenesis of Human Cardiac Myxoma

• Published in: Circulation Journal 2003, Vol.67(1), pp.54-60
• Main Authors: Zhang, Tianshu, Koide, Naohiko, Wada, Yuko, Tsukioka, Katsuaki, Takayama, Kei, Kono, Tetsuya, Kitahara, Hiroto, Amano, Jun
• Format: Article
• Language: English
• Subjects: Angiogenesis; Biological and medical sciences; Blood Vessels - pathology; Cardiac myxoma; Cardiology. Vascular system; CC chemokine receptor-2; Cell Count; Chemokine CCL2 - metabolism; Heart; Heart Neoplasms - complications; Heart Neoplasms - metabolism; Heart Neoplasms - pathology; Humans; Immunohistochemistry - methods; Macrophages - pathology; Medical sciences; Microcirculation; Middle Aged; Monocyte chemotactic protein-1; Myxoma - complications; Myxoma - metabolism; Myxoma - pathology; Neovascularization, Pathologic - etiology; Receptors, CCR2; Receptors, Chemokine - metabolism; Staining and Labeling; Thymidine phosphorylase; Thymidine Phosphorylase - metabolism; Tissue Distribution; Tumors of the heart
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.67.54

Angiogenesis is indispensable to tumor development and proliferation. The aim of this study was to investigate whether the expression of monocyte chemotactic protein-1 (MCP-1) and of thymidine phosphorylase (TP) correlates with the angiogenesis and clinicopathologic features in cardiac myxoma. Paraffin-embedded specimens of 17 resected cardiac myxomas were immunohistochemically stained for MCP-1, CC chemokine receptor-2 (CCR-2), TP, CD31, and CD68. Correlations among MCP-1 expression, TP expression, microvessel count (determined by CD31 staining), macrophage count (determined by CD68 staining), and the clinicopathologic features of the patients were analyzed statistically. Immunohistochemical analysis revealed that MCP-1 and TP were expressed in myxoma cells, as well as in stromal cells such as infiltrating cells, fibroblast-like cells and endothelial cells. CCR-2 was abundantly expressed in stromal infiltrating cells in all myxomas and occasionally in the endothelial cells. In the tumor stroma, the major source of MCP-1, TP and CCR-2 was macrophages, and the sites of positive staining for MCP-1, TP and CCR-2 matched in most of the myxomas. Statistical analysis revealed that the proportions of MCP-1-positive myxoma and stromal cells, and TP-positive myxoma and stromal cells significantly correlated with increased microvessel count. The proportions of MCP-1-positive myxoma and stromal cells significantly correlated with the proportion of TP-positive stromal cells. The mean microvessel count in myxomas with both high tumor and high stromal MCP-1 or TP expression was significantly higher than that in myxomas with low tumor and low stromal MCP-1 or TP expression. Small tumors (≤55 mm in diameter) exhibited high MCP-1 or TP expression, and the microvessel count in small tumors was significantly higher than in large myxomas. Although the difference was not significant, myxomas with both high tumor and high stromal MCP-1 expression had a higher macrophage count than other myxomas. These results indicate that in cardiac myxoma, MCP-1 and TP may be regarded as important angiogenic signals accompanying growth. (Circ J 2003; 67: 54 - 60)