CD13/APN transcription is regulated by the proto-oncogene c-Maf via an atypical response element.
(41/119)
Angiogenic growth factors induce the transcription of the cell surface peptidase CD13/APN in activated endothelial cells of the tumor vasculature. Inhibition of CD13/APN abrogates endothelial invasion and morphogenesis in vitro and tumor growth in vivo suggesting a critical functional role for CD13 in angiogenesis. Experiments to identify the transcription factors responsible for this regulation demonstrated that exogenous expression of the proto-oncogene c-Maf, but not other bZip family members tested, potently activates transcription from a critical regulatory region of the CD13 proximal promoter between -115 and -70 bp which is highly conserved among mammalian species. Using promoter mutation, EMSA and ChIP analyses we established that both endogenous and recombinant c-Maf directly interact with an atypical Maf response element contained within this active promoter region via its basic DNA/leucine zipper domain. However full activity of c-Maf requires the amino-terminal transactivation domain, and site-directed mutation of putative phosphorylation sites within the transactivation domain (serines 15 and 70) shows that these sites behave in a dramatic cell type-specific manner. Therefore, this atypical response element predicts a broader range of c-Maf target genes than previously appreciated and thus impacts its regulation of multiple myeloma as well as endothelial cell function and angiogenesis. (+info)
Endothelial cells express the interleukin-1 receptor type I.
(42/119)
Interleukin-1 (IL-1) profoundly affects a number of functions of vascular cells. Two distinct IL-1 receptors (IL-1R) are expressed on different cell types: the 80 Kd IL-1RI on T cells and fibroblasts, and the 68 Kd IL-1RII on B cells and myelomonocytic cells. The presence and functionality of IL-1R on vascular cells has been investigated by using polyomatransformed mouse endothelial cell (EC) lines (sEnd.1 and tEnd.1). These cells expressed specific and saturable binding sites for IL-1 (1,273 sites per cell with kd 9.5 x 10(-11) mol/L for sEnd.1, and 771 sites per cell with kd 8.5 x 10(-11) mol/L for tEnd.1, with radioiodinated IL-1 alpha as ligand). Binding of IL-1 was also evident at single cell level by autoradiography. By cross-linking studies, the molecular weight of the IL-1 binding protein on EC was approximately 80 Kd. This was confirmed by the presence in EC of mRNA for the 80 Kd IL-1RI. The IL-1RI on EC was apparently functional, since EC responded to IL-1 with IL-6 mRNA expression and IL-6 bioactivity production. These results were extended to human EC and vascular smooth muscle cells, which were also found to express mRNA for IL-1RI. (+info)
Prox-1 promotes invasion of kaposiform hemangioendotheliomas.
(43/119)
Kaposiform hemangioendothelioma with distant lymphangiomatosis without an association to Kasabach-Merritt-Syndrome in a female adult!
(44/119)
Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor which usually occurs in infants. Clinically it appears as ill-defined red to purple indurated plaque. KHE is commonly associated with Kasabach-Merritt syndrome (KMS) and lymphangiomatosis. Microscopically, the tumor is composed of infiltrating lobulated nodules with slitlike or crescentic vessels which are poorly canalized and lined by spindle shaped endothelial cells. We report a 36-year old female who developed a reddish tumor on the chest. Histological examination revealed a KHE, which was clinically not associated with thrombocytopenia or bleeding complications, but lymphangiomatosis at the right submandibular region. The association of KHE in a female adult with lymphangioma rather than KMS in this case supports the hypothesis that such an association may represent a benign subform of this disease in an adult and excision seems to be curative. (+info)
Systemic reactive angioendotheliomatosis-like syndrome in a steer presumed to be persistently infected with bovine viral diarrhea virus.
(45/119)
Retiform hemangioendothelioma with lymph node metastasis: a rare entity.
(47/119)
Retiform hemangioendothelioma (RH) is a rare, recently described, unique kind of low grade angiosarcoma. The tumor is characterized by distinctive arborizing blood vessels that mimic the appearance of rete testis. The tumor chiefly originates from the skin and subcutaneous tissue and has a tendency to recur locally. Only one case with lymph node metastasis has been reported previously. Another such rare case of RH is being reported in an adult female who presented with a subcutaneous nodule, underwent multiple recurrences and uniquely metastasized to regional lymph node. (+info)
Cerebral neoplastic angioendotheleosis complicated by hypercalcaemia.
(48/119)
This is a case report of a 67 year old man who presented with a fluctuating level of consciousness and myoclonic jerks caused in part by hypercalcaemia. The diagnosis of cerebral neoplastic angioendotheleosis was only made later on brain biopsy and is the first report of the occurrence of hypercalcaemia in neoplastic angioendotheleosis. (+info)