Expression of the cell adhesion molecule CEACAM1 in melanomas is an independent factor for the risk of metastasis with a predictive value superior to that of tumor thickness. We have previously shown that CEACAM1 co-localizes at the tumor-stroma interface of invading melanoma masses with integrin ␤ 3 and that these two adhesion molecules interact via the CEACAM1 cytoplasmic domain. To address the functional consequences of CEACAM1 expression, we investigated invasion and migration of melanocytic and melanoma cells that stably express CEACAM1 using two different in vitro systems. Here, we demonstrate that CEACAM1 expression markedly enhances cell invasion and migration. The enhanced invasion and migration of CEACAM1-transfected cells was dependent on the presence of Tyr-488 within the full-length cytoplasmic CEACAM1 domain. Treatment with anti-CEACAM monoclonal antibodies blocked CEACAM1enhanced cell invasion and cell migration in a dosedependent manner. Furthermore, the enhanced invasion and migration of CEACAM1-transfected melanoma cells was blocked by integrin-antagonizing RGD peptides. Expression of integrin ␤ 3 induces the up-regulation of CEACAM1 in melanocytic MEL6 cells. These results strengthen the view that CEACAM1 and ␣ v ␤ 3 integrin are functionally interconnected with respect to the invasive growth of melanomas.

The tumor uptake of (64)Cu-DOTA-1C1 measured by microPET imaging reflects tumor EphA2 expression level in vivo. This is, to our knowledge, the first report of quantitative radioimmunoPET imaging of EphA2 in living subjects. Future clinical investigation of (64)Cu-DOTA-1C1 is warranted.

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CEACAM1 is a cell adhesion molecule that has been implicated in a number of physiological processes (eg, tumor suppressor in epithelial tissues, potent angiogenic factor in microvessel formation, microbial receptor in human granulocytes and epithelial cells). The mechanism of CEACAM1 action is still largely unresolved but recent findings demonstrated that the cytoplasmic CEACAM1 domain is linked indirectly to the actin-based cytoskeleton. We have isolated integrin beta(3) as an associated protein using CEACAM1 tail affinity purification. This association depends on phosphorylation of Tyr-488 in the CEACAM1 cytoplasmic domain. Confocal laser scanning microscopy confirmed in vivo colocalization of both molecules in human granulocytes and epithelial cells. Furthermore, the concentrated colocalization at the tumor-stroma interface of invading melanoma masses suggests a functional role of CEACAM1-integrin beta(3) interaction in melanoma invasion. Moreover, colocalization of the two adhesion molecules is also found at the apical surface of glandular cells of pregnancy endometrium. Colocalization of CEACAM1 and integrin beta(3) at the transitional zone from proliferative to invasive extravillous trophoblast of the maternal-fetal interface supports a role for CEACAM1/integrin beta(3) complexes in cell invasion.

-The neuroprotective effects of dexmedetomidine have been reported by many investigators; however its underlying mechanism to reduce neuronal injury during a prolonged anesthesia remains unclear. In this study, we investigated the neurotoxic effects of dexmedetomidine in fetal monkey brains. In the present study, we compare the neurotoxic effects of dexmedetomidine and ketamine, a general anesthetic with a different mechanism of action, in fetal cynomolgus monkeys. Twenty pregnant monkeys at approximate gestation day 120 were divided into 4 groups: non-treatment controls (Group 1); ketamine at 20 mg/kg intramuscularly followed by a 12-hr infusion at 20-50 mg/kg/hr (Group 2); dexmedetomidine at 3 μg/kg intravenously (i.v.) over 10 min followed by a 12-hr infusion at the human equivalent dose (HED) of 3 μg/kg/hr (Group 3); and dexmedetomidine at 30 μg/kg i.v. over 10 min followed by a 12-hr infusion at 30 μg/kg/hr, 10 times HED (Group 4). Blood samples from both dams and fetuses were measured for concentration of dexmedetomidine. Each fetus was perfusion-fixed, serial sections were cut through the frontal cortex, and stained to detect for apoptosis (activated caspase 3 and TUNEL) and neurodegeneration (silver stain). In utero treatment with ketamine resulted in marked apoptosis and degeneration primarily in layers I and II of the frontal cortex. In contrast, fetal brains from animals treated with dexmedetomidine showed none to minimal neuroapoptotic or neurodegenerative lesions at both low-and high-dose treatments. Plasma levels confirmed systemic exposure of dexmedetomidine in both dams and fetuses. In conclusion, these results demonstrate that dexmedetomidine at both low-dose (HED) and highdose (10 times HED) does not induce apoptosis in the frontal cortex (layers I, II, and III) of developing brain of cynomolgus monkeys.