ABSTRACT
Tumor endothelial marker 1 (TEM1), also known as endosialin or CD248, is a type I transmembrane glycoprotein containing a C-type lectin-like domain. It is highly expressed in pericytes and fibroblasts. Dermal fibroblasts play a pivotal role during cutaneous wound healing, especially in the proliferative phase. However, the physiological function of TEM1 in wound healing is still undetermined. During the process of wound healing, the expression of both TEM1 and platelet-derived growth factor (PDGF) receptor α was highly upregulated in myofibroblasts. In vivo, fibroblast activation and collagen deposition in granulation tissues were attenuated, and wound healing was retarded in TEM1-deleted mice. In vitro, the migration, adhesion, and proliferation of NIH3T3 cells were suppressed following TEM1 knockdown by short hairpin RNA. In PDGF-BB-treated NIH3T3 cells, the downstream signal and mitogenic, and chemoattractive effects were inhibited by TEM1 knockdown. In addition, TEM1 and PDGF receptor α were colocalized in subcellular organelles in fibroblasts, and the association of TEM1 and PDGF receptor α was demonstrated by coimmunoprecipitation. In summary, these findings suggested that TEM1, in combination with PDGF receptor α, plays a critical role in wound healing by enhancing the mitogenic and chemoattractive effects of PDGF-BB and collagen deposition in myofibroblasts.
Subject(s)
Antigens, CD/genetics , Gene Expression Regulation , Neoplasm Proteins/genetics , Receptors, Platelet-Derived Growth Factor/genetics , Wound Healing/genetics , Wounds and Injuries/pathology , Animals , Blotting, Western/methods , Disease Models, Animal , Humans , Mice , Mice, Transgenic , Random Allocation , Real-Time Polymerase Chain Reaction/methods , Time Factors , Treatment Outcome , Up-Regulation , Wound Healing/physiology , Wounds and Injuries/metabolismABSTRACT
Neuroblastoma is the second most common retroperitoneal tumour in children after Wilms' tumour. When it originates in the retroperitoneum, neuroblastoma usually presents as an abdominal mass with clinical manifestations of nausea, vomiting and weight loss. Imaging studies of this tumour demonstrate a heterogeneous mass with an irregular capsule and visible calcifications. Encasement and compression of the abdominal vessels, especially the inferior vena cava, are often observed. However, stenosis of the inferior vena cava has never been reported to be associated with this tumour. Here, we present a case of a 5-month-old boy with a right retroperitoneal tumour with extensive encasement of the inferior vena cava and significant narrowing of its distal part between the venous bifurcation and the tumour capsule. To our knowledge, this is the first case of neuroblastoma with this manifestation in a child.