Spindle cells isolated from Kaposi's sarcoma-like lesions of BKV/tat-transgenic mice co-express markers of different cell types.
OBJECTIVE
To characterize murine spindle cells isolated from Kaposi's sarcoma-like skin lesions developed in BK virus (BKV)/tat-transgenic mice.


METHODS
Kaposi's sarcoma-like spindle cells isolated from the lesions were propagated in vitro, and their phenotype was investigated using a panel of antibodies against various cell markers and angiogenic factors. Immunofluorescence and Western blot techniques were used.


RESULTS
We observed co-expression of antigens specific for endothelial, smooth muscle and antigen-presenting cells, suggesting that cells from the TTB cell line represent poorly differentiated vascular precursors. Since TTB cells were derived from highly vascularized skin lesions, it is noteworthy that they synthesize a complex mixture of angiogenic factors, including fibroblast growth factor-2, vascular endothelial growth factor, placental growth factor, and hepatocyte growth factor. Due to their role in invasiveness and angiogenesis, we also observed the expression of urokinase plasminogen activator (uPA), uPA receptor, and plasminogen activator inhibitor-type 1 by TTB cells.


CONCLUSIONS
Our results suggest that TTB cells share several features with human Kaposi's sarcoma spindle cells and can be a useful in vitro system to study the molecular mechanisms involved in Kaposi's sarcoma pathogenesis. Moreover, they synthesize a complex mixture of angiogenic factors and are growth-inhibited by the anti-angiogenic drug AGM-1470.
Cavallaro
U
U
Department of Biological and Technological Research (DIBIT), San Raffaele Scientific Institute, Milan, Italy.
Gasparini
G
G
Soria
M R
MR
Maier
J A
JA
D000818:Animals; D002460:Cell Line; D015756:Genes, tat; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D009389:Neovascularization, Pathologic; D010641:Phenotype; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator; D012514:Sarcoma, Kaposi / Q000098:blood supply / Q000235:genetics / Q000473:pathology*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; C524899:Plaur protein, mouse; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator