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Purpose: Uveal melanoma is the most common primary intraocular malignant tumor in adults and is defined by a poor natural outcome, as 50% of patients die from metastases. The aim of this study was to develop and characterize a panel of human uveal melanoma xenografts transplanted into immunodeficient mice.Experimental Design: Ninety tumor specimens were grafted into severe combined immunodeficient mice, and 25 transplantable xenografts were then established (28%). Relationship between tumor graft and clinical, biological, and therapeutic features of the patients included were investigated. Characterization of 16 xenografts included histology, molecular analyses by immunohistochemistry, genetic alteration analysis (single-nucleotide polymorphism), and specific tumor antigen expression by quantitative reverse transcription-PCR. Pharmacologic characterization (chemosensitivity) was also done in four models using two drugs, temozolomide and fotemustine, currently used in the clinical management of uveal melanoma.Results: Take rate of human uveal melanoma was 28% (25 of 90). Tumor take was independent of size, histologic parameters, or chromosome 3 monosomy but was significantly higher in metastatic tumors. Interestingly, in vivo tumor growth was prognostic for a lower metastasis-free survival in patients with primary tumors. A high concordance between the patients' tumors and their corresponding xenografts was found for all parameters tested (histology, genetic profile, and tumor antigen expression). Finally, the four xenografts studied displayed different response profiles to chemotherapeutic agents.Conclusions: Based on these results, this panel of 16 uveal melanoma xenografts represents a useful preclinical tool for both pharmacologic and biological assessments. Clin Cancer Res; 16(8); 2352-62. ©2010 AACR.Uveal melanoma is the most common primary intraocular malignant tumor in adults. Despite the increased diagnostic accuracy and the development of conservative and effective treatments on primary tumor sites, such as plaque radiotherapy and photon beam therapy, the mortality remains stable and 50% of patients die from metastases that frequently involve the liver. Chemotherapy, such as oral temozolomide and intra-arterial fotemustine used at the metastatic stage, induces very low response rates, 14.3% and 36%, respectively, and a median survival time of 6.7 and 15 months (1-3). No postoperative adjuvant therapies are currently available to decrease the risk of metastases. Several prognostic factors of disseminated relapse after initial ophthalmologic treatment have been determined, including location with respect to the equator, monosomy 3, and retinal detachment (4). However, no effect of these prognostic markers on patient care can be envisaged in the absence of effective systemic therapies.The growing body of knowledge about molecular and genetics events involved in oncogenesis and tumor progression has led to the identification of new therapeutic targets and therapeutic agents. Preclinical investigatio...

Integrins are the major adhesive receptors for extracellular matrix and have various roles in development. To determine their role in cell migration, the gene encoding the β1 integrin subunit (Itgb1) was conditionally deleted in mouse neural crest cells just after their emigration from the neural tube. We previously identified a major defect in gut colonisation by conditional Itgb1-null enteric neural crest cells (ENCCs) resulting from their impaired migratory abilities and enhanced aggregation properties. Here, we show that the migration defect occurs primarily during the invasion of the caecum, when Itgb1-null ENCCs stop their normal progression before invading the caecum and proximal hindgut by becoming abnormally aggregated. We found that the caecum and proximal hindgut express high levels of fibronectin and tenascin-C, two well-known ligands of integrins. In vitro, tenascin-C and fibronectin have opposite effects on ENCCs, with tenascin-C decreasing migration and adhesion and fibronectin strongly promoting them. Itgb1-null ENCCs exhibited an enhanced response to the inhibitory effect of tenascin-C, whereas they were insensitive to the stimulatory effect of fibronectin. These findings suggest that β1 integrins are required to overcome the tenascin-C-mediated inhibition of migration within the caecum and proximal hindgut and to enhance fibronectin-dependent migration in these regions.