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.

Genotype-phenotype analysis of ocular findings in Rubinstein-Taybi syndrome - A case report and review of literature.

BACKGROUND: Rubinstein-Taybi syndrome (RSTS) is a rare genetic syndrome with a wide range of phenotypic presentations, including characteristic facial features. A variety of ocular abnormalities have been described in patients with RSTS. The genetic etiology of RSTS is heterogeneous but often involves two major genes, CREBBP (cAMP-response element binding protein-binding protein) and EP300 (E1A binding protein p300), with CREBBP variants responsible for the majority of the cases. MATERIALS AND METHODS: We report a new case of female patient with a novel variant in CREBBP (c.4495C>G), with clinical features consistent with RSTS. We performed a literature review to search for possible genotype-phenotype relationships between the type of variant in CREBBP and frequency of ocular presentations. A PubMed search generated 12 articles that met our inclusion criteria. With the addition of our patient, there were a total of 163 patients included for mutation analysis (164 variants given one patient had two different variants). RESULTS: Our review revealed that the most common variant types were frameshift (25%), gross deletion (23%), nonsense (18%), and intragenic deletions (13%). There does not appear to be an obvious hot spot location. A total of 127 patients were included for genotype-phenotype analysis of ocular features (36 patients were excluded as unable to discern variant type). The most frequent ocular features in patients with RSTS were down-slanting palpebral fissure (74%), arched eyebrows (56%), long eyelashes (52%), and strabismus (23%). CONCLUSIONS: Our results suggest that currently there is no clear genotype-phenotype relationship between the type of variant and frequency of associated ocular features in RSTS patients.

Chromosome 6p25 deletion syndrome: A case report and review of ophthalmic features.

The 6p25 deletion syndrome is a rare genetic disorder characterized by a wide spectrum of congenital anomalies. Ophthalmic abnormalities appear to be highly associated with the syndrome, although this relationship has not been well characterized to date. We conducted a systematic literature review to highlight the ocular features in patients with this deletion syndrome and describe a 7-month-old female who has a 6.07 MB 6p25.1p25.3 deletion and a 4.25 MB 17q25.3 duplication. Our patient presented with multiple congenital anomalies, including macrocephaly, frontal bossing, low set ears, tent-shaped mouth, saddle nose, flat midface, and hearing impairment. Her ophthalmic features included proptosis, down-slanting palpebral fissures, hypertelorism, nystagmus, bilateral posterior embryotoxon, and decentered and abnormally shaped pupils. A systematic review of the published cases with sufficient clinical eye descriptions included 63 cases with a confirmed 6p25 deletion. The most common eye findings observed were posterior embryotoxon, iris hypoplasia, corectopia, cornea opacity, and glaucoma.

Liquid Biopsy in Uveal Melanoma: Are We There Yet?

In the era of precision oncology, major strides are being made to use individual tumor information for clinical decision-making. Differing from traditional biopsy methods, the emerging practice of liquid biopsy provides a minimally invasive way of obtaining tumor cells and derived molecules. Liquid biopsy provides a means to detect and monitor disease progression, recurrence, and treatment response in a noninvasive way, and to potentially complement classical biopsy. Uveal melanoma (UM) is a unique malignancy, with diagnosis heavily reliant on imaging, few repeat biopsies, and a high rate of metastasis, which occurs hematogenously and often many years after diagnosis. In this disease setting, a noninvasive biomarker to detect, monitor, and study the disease in real time could lead to better disease understanding and patient care. While advances have been made in the detection of tumor-disseminated components, sensitivity and specificity remain important challenges. Ambiguity remains in how to interpret current findings and in how liquid biopsy can have a place in clinical practice. Related publications in UM are few compared to other cancers, but with further studies we may be able to uncover more about the biology of disseminated molecules and the mechanisms involved in the progression to metastasis.

Uveal Melanoma-Derived Extracellular Vesicles Display Transforming Potential and Carry Protein Cargo Involved in Metastatic Niche Preparation.

Extracellular vesicles (EVs) carry molecules derived from donor cells and are able to alter the properties of recipient cells. They are important players during the genesis and progression of tumors. Uveal melanoma (UM) is the most common primary intraocular tumor in adults and is associated with a high rate of metastasis, primarily to the liver. However, the mechanisms underlying this process are poorly understood. In the present study, we analyzed the oncogenic potential of UM-derived EVs and their protein signature. We isolated and characterized EVs from five UM cell lines and from normal choroidal melanocytes (NCMs). BRCA1-deficient fibroblasts (Fibro-BKO) were exposed to the EVs and analyzed for their growth in vitro and their reprograming potential in vivo following inoculation into NOD-SCID mice. Mass spectrometry of proteins from UM-EVs and NCM-EVs was performed to determine a protein signature that could elucidate potential key players in UM progression. In-depth analyses showed the presence of exosomal markers, and proteins involved in cell-cell and focal adhesion, endocytosis, and PI3K-Akt signaling pathway. Notably, we observed high expression levels of HSP90, HSP70 and integrin V in UM-EVs. Our data bring new evidence on the involvement of UM-EVs in cancer progression and metastasis.

Beta-blockers exert potent anti-tumor effects in cutaneous and uveal melanoma.

BACKGROUND: Melanoma is a life-threatening group of cancers mainly affecting the skin (cutaneous melanoma, CM) and the eyes (uveal melanoma, UM). Nearly half of patients with UM develop liver metastases regardless of the primary treatment. For this reason, adjuvant therapy to prevent disease progression is essential to improve survival of patients with melanoma. Beta-adrenoceptors (ß-AR) have emerged as novel targets to inhibit tumor growth and dissemination in CM, but have not been investigated in UM. METHODS: The aim of this study was to comprehensively evaluate the effects of a non-selective ß-blocker in UM and CM. Propranolol was tested on four UM and two CM cell lines to determine the effects of this beta-blocker. The expression of ß-AR in UM was assessed in enucleated eyes of 36 patients. RESULTS: The results showed that propranolol exerts potent anti-proliferative effects, attenuates migration, reduces VEGF and induces cell cycle arrest and apoptosis in both UM and CM in a dose-dependent manner. Furthermore, levels of cell-free DNA released from the cells correlated to propranolol treatment and may be an indicator of treatment response. Finally, immunohistochemical analysis revealed the expression of ß1 and ß2 adrenoceptors in all UM patients, with higher expression seen in the more aggressive epithelioid versus less aggressive spindle cells. CONCLUSIONS: Collectively our data suggest that a nonselective beta-blocker may be effective against melanoma. For the first time, we show potent anti-tumor effects in UM cells following propranolol administration and expression of ß1 and ß2 adrenoceptors in patient tissue.