Lymphatic and vascular origin of Kaposi's sarcoma spindle cells during tumor development

✍ Scribed by Pawan Pyakurel; Fatemeh Pak; Amos. R. Mwakigonja; Ephata Kaaya; Thomas Heiden; Peter Biberfeld

• Book ID: 102862430
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: French
• Weight: 550 KB
• Volume: 119
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.21969

✦ Synopsis

Abstract

The histogenesis of Kaposi's sarcoma (KS) tumor spindle cells (SC) remains controversial but several immunohistochemical studies favor a lymphatic origin. Twenty KS surgical biopsies were analyzed for the coexpression of LANA, CD34, LYVE‐1, D2‐40, VEGFR‐2, VEGFR3 by using double or triple immunostaining. Most of the SC in both early and late KS expressed the lymphatic markers LYVE‐1, D2‐40 and VEGFR‐3 and the blood vascular endothelial/endothelial precursor cell markers CD34 and endothelial stem cell marker VEGFR‐2. All the LANA+ SC in early and late KS were LYVE‐1+, but only 75% of these LANA+ cells were CD34+. The CD34+/LANA+ cells increased from early‐ (68.8%) to late‐stage KS (82.2%). However, approximately 18% of the LANA+ SC in early KS were CD34− but were LYVE‐1+, suggesting that resident lymphatic endothelial cells (LEC) are targeted for primary infection by human herpesvirus‐8. This LANA+/LYVE‐1+/CD34− (resident LEC) cell population clearly decreased during the development of KS from early (18.7%) to late KS (2.9%). Thus, in late stages of KS, most SC were LANA+/CD34+/LYVE‐1+. However, in both early‐ and late‐stage KS, approximately 18% of the SC were CD34+/LANA‐/LYVE‐1− and could represent newly recruited endothelial precursor cells, which become infected in the lesion and eventually undergo a phenotype switch expressing LEC markers. Our study apparently indicates that KS represents a unique variant of tumor growth with continues recruitment of tumor precursor cells as well as proliferation and decreased apoptosis of SC. © 2006 Wiley‐Liss, Inc.