Delineating three-dimensional behavior of uveal melanoma cells under anchorage independent or dependent conditions.

BACKGROUND: Although rare, uveal melanoma (UM) is a life-threatening malignancy. Understanding its biology is necessary to improve disease outcome. Three-dimensional (3D) in vitro culture methods have emerged as tools that incorporate physical and spatial cues that better mimic tumor biology and in turn deliver more predictive preclinical data. Herein, we comprehensively characterize UM cells under different 3D culture settings as a suitable model to study tumor cell behavior and therapeutic intervention. METHODS: Six UM cell lines were tested in two-dimensional (2D) and 3D-culture conditions. For 3D cultures, we used anchorage-dependent (AD) methods where cells were embedded or seeded on top of basement membrane extracts and anchorage-free (AF) methods where cells were seeded on agarose pre-coated plates, ultra-low attachment plates, and on hanging drops, with or without methylcellulose. Cultures were analyzed for multicellular tumor structures (MCTs) development by phase contrast and confocal imaging, and cell wellbeing was assessed based on viability, membrane integrity, vitality, apoptotic features, and DNA synthesis. Vascular endothelial growth factor (VEGF) production was evaluated under hypoxic conditions for cell function analysis. RESULTS: UM cells cultured following anchorage-free methods developed MCTs shaped as spheres. Regardless of their sizes and degree of compaction, these spheres displayed an outer ring of viable and proliferating cells, and a core with less proliferating and apoptotic cells. In contrast, UM cells maintained under anchorage-dependent conditions established several morphological adaptations. Some remained isolated and rounded, formed multi-size irregular aggregates, or adopted a 2D-like flat appearance. These cells invariably conserved their metabolic activity and conserved melanocytic markers (i.e., expression of Melan A/Mart-1 and HMB45). Notably, under hypoxia, cells maintained under 3D conditions secrete more VEGF compared to cells cultured under 2D conditions. CONCLUSIONS: Under an anchorage-free environment, UM cells form sphere-like MCTs that acquire attributes reminiscent of abnormal vascularized solid tumors. UM cells behavior in anchorage-dependent manner exposed diverse cells populations in response to cues from an enriched extracellular matrix proteins (ECM) environment, highlighting the plasticity of UM cells. This study provides a 3D cell culture platform that is more predictive of the biology of UM. The integration of such platforms to explore mechanisms of ECM-mediated tumor resistance, metastatic abilities, and to test novel therapeutics (i.e., anti-angiogenics and immunomodulators) would benefit UM care.

Protein profile of purified plasma- and aqueous humor-derived extracellular vesicles from patients with ocular toxoplasmosis.

PURPOSE: To characterize the extracellular vesicle protein cargo in the aqueous humor and plasma of patients with ocular toxoplasmosis. METHODS: Aqueous humor and plasma were collected from six patients with active ocular toxoplasmosis and six patients with cataract. Extracellular vesicles were isolated, and western blotting and mass spectrometry were performed for protein analysis. RESULTS: All plasma samples from patients with ocular toxoplasmosis and cataract were positive for the tetraspanins CD63 and TSG101. However, the aqueous humor from patients with ocular toxoplasmosis was positive only for CD63. Sixty-seven new unreported proteins were identified in the aqueous humor and plasma of patients with the ocular toxoplasmosis and cataract. Of the 67 proteins, 10 and 7 were found only in the cataract and ocular toxoplasmosis groups, respectively. In general, these proteins were involved in immune system activation and retina homeostasis and were related to infections and retina-associated diseases. CONCLUSION: The distinct protein signatures between ocular toxoplasmosis and cataract may be helpful in the differential diagnosis of ocular toxoplasmosis. However, more studies are needed to better understand the role of these proteins in the pathogenesis of ocular toxoplasmosis.

Comprehensive clinical imaging, histopathological analysis and liquid biopsy-based surveillance of human uveal melanoma in a prolonged rabbit xenograft model.

Uveal melanoma is the most common intraocular tumor in adults. Our group has previously developed a human uveal melanoma animal model; however, adverse effects caused by the immunosuppressive agent, cyclosporine A, prevented animals from surviving more than 12 weeks. In this study, we tested multiple cyclosporine A doses over an extended disease course up to 20 weeks, providing complete clinical imaging of intraocular tumors, histopathological analysis and liquid biopsy biomarker analysis. Twenty albino rabbits were divided into four groups with different daily cyclosporine A schedules (0-10 mg/kg) and inoculated with human uveal melanoma cell lines, 92.1 or MP41, into the suprachoroidal space. Rabbits were monitored with fundoscopy, ultrasound and optical coherence tomography. Intraocular tumors (macroscopic or microscopic) were detected in all study animals. Tumor size and growth were correlated to cyclosporine A dose, with tumors regressing when cyclosporine A was arrested. All tumors expressed HMB-45 and MelanA; however, tumor size, pigmentation and cell morphology differed in 92.1 vs. MP41 tumors. Finally, across all groups, circulating tumor DNA from plasma and aqueous humor was detected earlier than tumor detection by imaging and correlated to tumor growth. In conclusion, using three clinically relevant imaging modalities (fundoscopy, ultrasonography and optical coherence tomography) and liquid biopsy, we were successfully able to monitor tumor progression in our rabbit xenograft model of human uveal melanoma.

Incidence of epithelial lesions of the conjunctiva in a review of 12,102 specimens in Canada (Quebec) / Incidência de lesões epiteliais da conjuntiva em revisão de 12.102 casos no Canadá (Quebec)

PURPOSE: The purpose of this study was to assess the relative frequency of epithelial lesions of the conjunctiva in Canada. METHODS: A retrospective study of 12,102 consecutive cases received during 16 years (1993-2009) at the Henry C. Witelson Ocular Pathology Laboratory in Montreal, Canada, was performed. Demographic data was retrieved from histopathological request forms and specimens were categorized and analyzed by mean percentage. The relative frequency of epithelial lesions of the conjunctiva from a single center in Canada, representing the province of Quebec was reviewed. RESULTS: Of the 12,102 specimens reviewed, 273 were conjunctival lesions (2.25 percent), including 86 epithelial tumors (0.71 percent) of the conjunctiva that comprised the studied sample. The average age of these patients was 59.9 ± 17.6 years, and gender distribution was 66 (69 percent) males and 30 (31 percent) females. Fifteen lesions (17.4 percent) were classified as squamous cell papillomas (mean age, 57.3 ± 16.7 years). Within the ocular surface squamous neoplasia (OSSN) spectrum, there were 10 (11.6 percent) actinic keratosis (63.8 ± 17.6 years), 27 (31.3 percent) cases of conjunctival intraepithelial neoplasia (CIN) with variable degrees of atypia (mild to moderate) (63.9 ± 15.3 years), 15 (17.4 percent) carcinomas in situ (66.7 ± 18.0 years), and 17 (19.7 percent) squamous cell carcinomas (SCC) (56.2 ± 19.4 years). Two other rare cases of malignant tumors included one basal cell carcinoma and one mucoepidermoid carcinoma. CONCLUSIONS: The distribution of our sample is similar to the one reported by the American Forces Institute of Pathology (AFIP) in 1994. When we compare our sample to others coming from countries with high levels of sunlight exposure, we found a lower incidence of ocular surface squamous neoplasia, including squamous cell carcinomas in Canada.

OBJETIVO: O estudo realizado teve como objetivo fornecer a relativa frequência de cada lesão epitelial de conjuntiva no Canadá. MÉTODOS: Trata-se de estudo retrospectivo de todos os casos recebidos durante 16 anos (1993-2009) no Henry C. Witelson Ocular Pathology Laboratory, em Montreal. Dados epidemiológicos foram obtidos por meio de requerimento e laudos histopatológicos, sendo classificados e analisados pelo porcentual na amostra. A relativa frequência de lesões epiteliais da conjuntiva foram obtidas em um único centro de análises no Canadá. RESULTADOS: Entre 12.102 espécimes revisadas, 273 foram lesões conjuntivais (2,25 por cento), sendo 86 tumores epiteliais (0,71 por cento) entre a amostra estudada. A idade média das lesões neoplásicas da conjuntiva foi de 59,9 ± 17,6 anos, e a distribuição por sexo foi de 66 (69 por cento) homens e 30 (31 por cento) mulheres. Quinze lesões (17,4 por cento) foram classificadas como papilomas de células escamosas (idade média 57,3 ± 16,7 anos). No grupo das neoplasias escamosas da superfície ocular (NESO) foram encontrados 10 (11,6 por cento) casos de queratose actínica, (63,8 ± 17,6 anos), 27 (31,3 por cento) casos de neoplasia intraepitelial (NIC), com moderada atipia (63,9 ± 15,3 anos), 15 (17,4 por cento) carcinomas in situ (66,7 ± 18,0 anos), e 17 (19,7 por cento) carcinomas de células escamosas (CCE) (56,2 ± 19,4 anos). Dois outros casos menos frequentes de tumores malignos foram incluídos; um carcinoma de célula basal e outro carcinoma mucoepidermoide. CONCLUSÃO: A distribuição de nossa amostra é semelhante a encontrada no Armed Forces Institute of Pathology (AFIP) em 1994, porém quando comparamos nossa amostra com estudos realizados em países com altos níveis de exposição solar observamos menor incidência de neoplasias escamosas da superfície ocular, incluindo-se carcinomas de células escamosas.