Expression of cancer stem cell markers and their correlation with pathogenesis in vascular tumors.

Vascular tumor, which belongs to a kind of complicated lesion in soft tissue tumor, is derived from mesenchymal tissue. Although many studies have been focused on the pathogenesis of vascular tumors in human, the specific mechanism of the vascular tumors was currently unclear. Previous studies have reported an association of cancer stem cells with the development of tumor in many solid tumors. Thus the purpose of this study was to explore whether different expression level of cancer stem cell markers including CD29, CD44, CD133, nestin and ALDH1 in vascular tumor may help to elucidate the possible pathogenesis of vascular tumor. In present study, tissues of 9 cases of hemangioma, 22 cases of hemangiosarcoma, 3 cases of Kaposi's sarcoma, and 5 cases of hemangioendothelioma were immunostained for CD29, CD44, CD133, nestin and ALDH1. Of the 39 vascular tumor cases included in the current study, CD29, CD133 and nestin were positive in most vascular tumor cases. Although CD44 and ALDH1 were observed in vascular tumor cases, the percentage of cells staining for the two markers was less than 2% in all cases of vascular tumor. Capillary hemangiomas exhibited significantly higher expression rate of CD29 and nestin compared with malignant vascular tumors and hemangioendotheliomas (P<0.05, Fisher's exact test), while CD44, CD133 and ALDH1 exhibited no statistically significant difference between these two groups. Pearson correlation analysis exhibited that CD29 expression and nestin expression in vascular tumor were no statistically significant relationship (C=0.288, P=0.063>0.05). Our findings confirmed that the five cancer stem cells markers, including CD29, CD44, CD133, nestin and ALDH1, exhibited different expression levels in vascular tumors and demonstrated that immunohistochemical analysis for cancer stem cells markers may provide useful information for studying the pathogenesis of vascular tumors.