Ocular Malignancy Research Articles

RNA Sequencing and Bioinformatic Analysis on Retinoblastoma Revealing that Cell Cycle Deregulation Is a Key Process in Retinoblastoma Tumorigenesis

Purpose: Retinoblastoma (RB) is a primary pediatric ocular malignancy that can be fatal with inadequate treatment. While multimodal treatments are applied for eye salvage, vision loss and metastasis can occur in some patients. The present study aimed to explore key pathways and factors in RB pathogenesis, which could be potential targets for novel RB treatments. Methods: RNA sequencing was performed on three RB tissues and referenced with three normal retinas. Differentially expressed genes (DEGs) were identified from sequencing data and further analyzed with clustering analysis, function and pathway enrichment, protein-protein interaction (PPI), and data-mining analysis in order to screen for tumorigenic relevancy. Results: A total of 331 DEGs were identified by clustering analysis of RB tissues, and the expression patterns were significantly distinguishable from normal retinas. Function and pathway enrichment and PPI analysis together showed that cell cycle was the most prominently upregulated pathway found in RB tissues. Following comprehensive bioinformatic analyses, six key genes relevant to cell cycle regulation were identified, namely BUB1, RRM2, TPX2, UBE2C, NUSAP1, and DTL. Conclusions: Cell cycle pathway and six relevant genes may be potential key factors in RB tumorigenesis and laying the foundation for prospective investigation on development of novel targeted therapies.

Epidemiology of invasive ocular surface squamous neoplasia in Canada during 1992–2010

BackgroundOcular surface squamous neoplasia (OSSN) is the most common non-pigmented ocular surface malignancy. It is classified as invasive OSNN (IOSSN) when the underlying stroma are infiltrated by dysplastic squamous epithelial...

Uveal melanoma-associated cancers revisited

BackgroundUveal melanoma (UM) is the most common primary ocular malignancy of adults. A small group of patients was found to express familial predisposition. Moreover, it may be preceded or followed by other malignancies elsewhere in the body. We aim to compare the incidence of UM and other associated cancers and study the factors that may influence each condition.Patients and methodsWe have collected the data from the Surveillance, Epidemiology and End Results database of nine US cancer registries for UM patients between 1973 and 2015. We calculated the standardised incidence ratios for single primary UM, first primary and second primary UM, and compared the groups for multiple factors.ResultsA total of 4946 patients were included in the study; 3863 with single primary UM, 646 developed a second primary malignancy following UM, and 437 patients developed second primary UM following a previous primary malignancy. The risk of developing UM increased after leukaemia, melanoma of the skin and prostate. On the other side, the risk of developing melanoma of the skin, thyroid, renal and other eye and orbit malignancies has increased significantly after initial UM. This risk was more evident in the age group between 50 and 70 years old. Cancer-specific survival was significantly higher in UM associated with other malignancies group compared with single primary UM.ConclusionOur study showed a different behaviour of the UM when associated with other tumours that exceed the known spectrum of hereditary UM. Further studies are required to dissect the genetic background of this behaviour.

Clinical Profile of Spontaneously Regressed Retinoblastoma Tumours

Retinoblastoma is leading ocular malignancy in children. Newer modalities of treatment have improved the survival and eye preservation rate. However, very few reported cases document spontaneous regression of tumour in eye without any treatment. The paediatric ophthalmology and ocular oncology unit of our tertiary eye institute had noted three cases between 1983 and 2015. We present clinical features at presentation and progress noted during follow up. Histopathologic confirmation of diagnosis in such cases is not possible. However, clinical diagnosis by expert in the field in these cases is reliable.

YAP/TAZ Activation Drives Uveal Melanoma Initiation and Progression

SUMMARYUveal melanoma (UM), the most common ocular malignancy, is characterized by GNAQ/11 mutations. Hippo/YAP and Ras/mitogen-activated protein kinase (MAPK) emerge as two important signaling pathways downstream of G protein alpha subunits of the Q class (GαQ/11)-mediated transformation, although whether and how they contribute to UM genesis in vivo remain unclear. Here, we adapt an adeno-associated virus (AAV)-based ocular injection method to directly deliver Cre recombinase into the mouse uveal tract and demonstrate that Lats1/2 kinases suppress UM formation specifically in uveal melanocytes. We find that genetic activation of YAP, but not Kras, is sufficient to initiate UM. We show that YAP/TAZ activation induced by Lats1/2 deletion cooperates with Kras to promote UM progression via downstream transcriptional reinforcement. Furthermore, dual inhibition of YAP/TAZ and Ras/MAPK synergizes to suppress oncogenic growth of human UM cells. Our data highlight the functional significance of Lats-YAP/TAZ in UM initiation and progression in vivo and suggest combination inhibition of YAP/TAZ and Ras/MAPK as a new therapeutic strategy for UM.

Non-Coding RNAs in Retinoblastoma.

Retinoblastoma (Rb) is the most common ocular pediatric malignancy that arises from the retina and is caused by a mutation of the two alleles of the tumor suppressor gene, RB1. Although early detection provides the opportunity of controlling the primary tumor with effective therapies, metastatic activity is fatal. Non-coding RNAs (ncRNAs) have emerged as important modifiers of a plethora of biological mechanisms including those involved in cancer. They are classified into short and long ncRNAs according to their length. Deregulation of all these molecules has also been shown to play a critical role in Rb pathogenesis and progression. It is believed that ncRNAs can provide new insights into novel regulatory mechanisms associated with clinical pathological characteristics, facilitating the development of therapeutic alternatives for the treatment of Rb. In this review, we describe a variety of ncRNAs, which capable of regulating the most likely candidate genes involved in the tumorigenesis of Rb, could prove useful in analyzing different aspects of this cancer.

1324P - Incidence and survival of uveal melanoma occurring as single cancer versus its occurrence as a first or second primary neoplasm

BackgroundUveal Melanoma (UVM) is the most common ocular malignancy. Many mutations were identified in affected patients defining genetic predisposition syndromes. Previous studies discussed separately the incidence of single or second primary ocular melanomas. However, understanding the genetic background, and relation to other tumors requires further investigation for defining the UVM subgroups, their shared developmental and, hence, the targeting mechanisms. MethodsWe used Surveillance Epidemiology and End Results program of the National Cancer Institute, United States, to review patients diagnosed with UVM, either as single primary or combined with other malignancies, between 1973 and 2015. We have calculated standardized incidence ratios (SIR) and measured risk in the form of Observed/Expected ratios (O/E) and Hazard Ratios (HR). ResultsWe have identified 7,386 patients diagnosed with single primary UVM, besides 646 with UVM followed by another malignancy and 437 patients diagnosed with a primary UVM after other malignancies. SIR of developing another malignancy following UVM was significant and increased most within the first 5 years following UVM following choroid uveal melanoma (1.198, 95%CI=1.056-1.353). The risk of developing melanomas of the skin, thyroid cancers, and kidney cancers, increased significantly within the first 5 years following UVM, with SIRs (3.763, 95%CI=2.539-5.372), (3.158, 95%CI=1.270-6.506), and (2.618, 95%CI=1.465-4.317), respectively. SIR of developing a second UVM following another malignancy was significant between the 5th and 10th years following the first cancer diagnosis (O/E=1.204, 95% CI=1.007-1.428), where the increase of UVM risk was highest among patients with primary prostate cancer (1.404, 95%CI=1.024-1.878) or leukemia (2.915, 95%CI=1.070-6.345). Cox models did not show a significant difference between the overall survival of single UVM and second UVM, but females showed better overall survival outcomes. In addition, Ciliary body tumors, and dark-skinned people were associated with worse survival outcomes. ConclusionsThe three groups of uveal melanoma showed different behaviors that may represent diverse underlying developmental mechanisms. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

SRSF2 Mutations in Uveal Melanoma: A Preference for In-Frame Deletions?

Background: Uveal melanoma (UM) is the most common primary ocular malignancy in adults in the Western world. UM with a mutation in SF3B1, a spliceosome gene, is characterized by three or more structural changes of chromosome 1, 6, 8, 9, or 11. Also UM without a mutation in SF3B1 harbors similar chromosomal aberrations. Since, in addition to SF3B1, mutations in U2AF1 and SRSF2 have also been observed in hematological malignancies, UM without a SF3B1 mutation—but with the characteristic chromosomal pattern—might harbor mutations in one of these genes. Methods: 42 UMs were selected based on their chromosomal profile and wildtype SF3B1 status. Sanger sequencing covering the U2AF1 (exon 2 and 7) hotspots and SRSF2 (exon 1 and 2) was performed on DNA extracted from tumor tissue. Data of three UM with an SRSF2 mutation was extracted from the The Cancer Genome Atlas (TCGA). Results: Heterozygous in-frame SRSF2 deletions affecting amino acids 92–100 were detected in two UMs (5%) of 42 selected tumors and in three TGCA UM specimens. Both the UM with an SRSF2 mutation from our cohort and the UM samples from the TCGA showed more than four structural chromosomal aberrations including (partial) gain of chromosome 6 and 8, although in two TCGA UMs monosomy 3 was observed. Conclusions: Whereas in myelodysplastic syndrome predominantly missense SRSF2 mutations are described, the observed SRSF2 mutations in UM are all in-frame deletions of 8–9 amino acids. This suggests that the R625 missense SF3B1 mutations and SRSF2 mutations in UM are different compared to the spliceosome gene mutations in hematological cancers, and probably target a different, as yet unknown, set of genes involved in uveal melanoma etiology.

Automating Quality Assurance of a Medical Particle Accelerator Safety System Using a Formal Language Driven Test Stand

At the Centre for Proton Therapy at the Paul Scherrer Institute, cancer patients are treated with a fixed beamline and in two gantries for ocular and nonocular malignancies, respectively. For the installation of a third gantry, a new patient safety system (PaSS) was developed and is subsequently being rolled out to update the existing areas. The aim of the PaSS is to interrupt the treatment whenever any subsystem detects a hazardous condition. To ensure correct treatment delivery, this system needs to be thoroughly tested as part of the regular quality assurance (QA) protocols as well as after any upgrade. In the legacy safety systems, unit testing required extensive use of resources: 2 weeks of work per area in the laboratory in addition to QA beam time. In order to significantly reduce the time, an automated PaSS test stand for unit testing was developed based on a PCI eXtensions for Instrumentation chassis with virtually unlimited I/Os that are synchronously stimulated or sampled at 1 MHz. It can emulate the rest of the facility using adapters to connect each type of interface. With it, the PaSS can be tested under arbitrary conditions. A VHSIC (very high speed integrated circuit) hardware description language-based formal language was developed to describe stimuli, expected behavior, and specific measurements, interpreted by a LabView runtime environment. This paper describes the tools and methodology being applied for unit testing and QA release tests for the new PaSS. It shows how automation and formalization made possible to increase the test coverage while significantly reducing the laboratory testing time and facility’s beam usage.

PRC1 gene silencing inhibits proliferation, invasion, and angiogenesis of retinoblastoma cells through the inhibition of the Wnt/β-catenin signaling pathway.

Retinoblastoma is an ocular malignancy occurring in childhood. The current study evaluates the ability of silenced PRC1 on retinoblastoma cell proliferation, and angiogenesis via the Wnt/β-catenin signaling pathway. A total of 36 cases of retinoblastoma tissues (n = 36) and normal retinal tissues (n = 10) were selected in the current study. Retinoblastoma cells presenting with the high PRC1 messenger RNA (mRNA) expression were selected among the WERI-Rb-1, HXO-RB44, Y79, SO-Rb50, and SO-Rb70 cells lines, and were transfected with siRNA-PRC1 and LiCl (the activator of the Wnt/β-catenin pathway). The expressions of PRC1, VEGF, Wnt1, β-catenin, CyclinD1, extent of β-catenin, and GSK-3β phosphorylation were evaluated. Cell proliferation, cell-cycle distribution, and cell invasion of retinoblastoma cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and Transwell assay. The angiogenesis of retinoblastoma cells was detected by tube formation assay. HXO-RB44 and WERI-Rb-1 cells were selected owing to the highest PRC1 mRNA expression. Meanwhile, PRC2 gene silencing presented lower expression levels of PRC1, VEGF, Wnt1, β-catenin, CyclinD1, extent of β-catenin and GSK-3β phosphorylation, decreased proliferation and invasion abilities, extended G0/G1 phase, and shortened S and G2/M phases of HXO-RB44 and WERI-Rb-1 cells, suggesting the silenced PRC2 inactivated Wnt/β-catenin pathway, so as to further restrain the retinoblastoma cell proliferation, invasion, and angiogenesis. These results support the view that PRC1 gene silencing could suppress the proliferation, and angiogenesis of retinoblastoma cells by repressing the Wnt/β-catenin pathway.

Characteristics, management, and outcome of ocular medulloepithelioma: systematic review of literature and case report

Background: Ocular medulloepithelioma (OM) is a rare ocular malignancy. This is a report of a rare case of medulloepithelioma that was misdiagnosed as retinoblastoma. Material and methods: A case report and review of published, peer-reviewed, English language literature reporting on ocular medulloepithelioma. Results: A seven-year-old girl presented with a white mass in the anterior chamber of her left eye. The initial diagnosis was retinoblastoma with anterior chamber invasion, and therefore it was enucleated. Microscopy showed a cellular tumour composed of malignant primitive cells forming sheets, rosettes, and tubular structures. Based on the presence of prominent pleomorphism the tumour was diagnosed as malignant teratoid medulloepithelioma. At last date of follow-up three years after enucleation, the patient was alive without metastasis. A systematic review of literature, analysed 177 cases of OM. The tumour was localised in the ciliary body in 134 (92%) cases, and 26 (23%) cases had extraocular extension. Primary management was enucleation in 84 (55%) cases, tumour resection in 32 (21%) cases, and radiation therapy in 20 (13%) cases. Histopathology disclosed benign features in 36 (22%) eyes, malignant features in 124 (78%) eyes, teratoid features in 72 (59%), and non-teratoid features in 51 (41%) eyes. At a mean follow-up of five years, 14 (8%) patients had metastasis, and six (6%) patients were dead. Conclusions: Ocular medulloepithelioma most commonly affects children. The most common type is the malignant teratoid type, but it has a favourable prognosis, and distant metastasis and mortality are relatively rare, at 8% and 6%, respectively.

Detection of Malignancy in Ocular Surface Lesions by Inverse Spectroscopic Optical Coherence Tomography and Two-Photon Autofluorescence.

PurposeAdvanced imaging is increasingly important in the diagnosis of ocular surface malignancy. Inverse spectroscopic optical coherence tomography (ISOCT) and two-photon autofluorescence microscopy (2P-AF) are emerging techniques capable of quantifying ultrastructural and metabolic changes, respectively. We aimed to detect malignancy in ocular surface lesions using ISOCT and 2P-AF.MethodsPortions of excised specimens from patients undergoing conjunctival biopsy at Boston Medical Center were imaged by ISOCT and/or 2P-AF, and submitted for histologic diagnosis. Lesions were categorized as malignant, premalignant (with dysplasia) or benign. ISOCT and 2P-AF findings were compared between categories.ResultsFourteen specimens from 13 patients were collected. The IS-OCT marker D was 2.2-fold higher in combined malignant and premalignant (4.27 ± 0.28, n = 3) versus benign (1.92 ± 0.26, n = 11) lesions (P = 9 × 10−4). ISOCT markers μs and μb were not significantly different. By 2P-AF, the redox ratio was 0.24-fold lower in premalignant (0.11 ± 0.004, n = 2) versus benign (0.45 ± 0.04, n = 9) lesions (P = 1.08 × 10−5).ConclusionsConjunctival lesions with higher malignant potential had higher D and lower redox ratios. Higher D can correlate with ultrastructural changes associated with malignancy, similar to what has been seen in cancers of the gut mucosa. Lower redox ratios can suggest the presence of the Warburg effect, which is associated with tumorigenesis.Translational RelevanceIS-OCT and 2P-AF can potentially be applied to the detection of malignancy or malignant potential in ocular surface lesions. ISOCT allows for the detection of nanoscale ultrastructural changes that are not resolvable by conventional OCT.

Detection of Extraocular Lesions in A Patient with Bilateral Retinoblastoma Using 18F-FDG PET/CT

Retinoblastoma is the most common ocular malignancy in children with a high mortality rate in metastatic disease, even under chemotherapy.

Human papillomavirus in ocular malignant tumours: a study from a tertiary eye care centre in North India

ObjectiveThe present study aims to detect the presence of human papillomavirus (HPV) in ocular malignant tumours, including retinoblastoma, eyelid squamous cell carcinoma (SCC), and sebaceous gland carcinoma (SGC), in the North Indian population. DesignProspective observational non randomized study. ParticipantsIn this study, 142 prospective cases of ocular malignant tumours (retinoblastoma, SGC, and SCC) were included. MethodsHPV was detected by multiplex PCR using PGMY09/11 primers in 142 patients with ocular malignancies. This was followed by genotyping using linear array (reverse hybridization). ResultsOf the 142 tumours studied, 72 were retinoblastoma, 30 SGC, and 40 SCC. The HPV genome was detected in 2.8% (4 of 142) of cases by multiplex PCR; all positive cases (4 of 40) were SCC. Genotyping revealed that all positives belonged to the high-risk HPV16 genotype. HPV-positive SCC patients had better disease-free survival. Retinoblastoma and SGC cases were negative for HPV. ConclusionsLow prevalence of HPV in ocular malignancies was observed in this study. The HPV genome was detected only in ocular squamous cell carcinoma cases and these patients were associated with better prognosis. HPV may not have a role in retinoblastoma and SGC in the North Indian population.

Proceedings of the Association for Research in Vision and Ophthalmology and Champalimaud Foundation Ocular Oncogenesis and Oncology Conference.

The 2018 Ocular Oncogenesis and Oncology Conference was held through a partnership of the Association for Research in Vision and Ophthalmology (ARVO) and the Champalimaud Foundation. Twenty-one experts from international ocular oncology centers, from the Champalimaud Clinical Centre and the Champalimaud Foundation Cancer Research Program, and from patient advocacy organizations, delivered lectures on subjects that ranged from global ocular oncology, to basic research in mechanisms of ocular malignancy, to clinical research in ocular cancers, and to anticipated future developments in the area. The scientific program of the conference covered a broad range of ocular tumors—including uveal melanoma, retinoblastoma, ocular surface tumors, and adnexal and intraocular lymphomas—and pathogenesis and management were deliberated in the context of the broader systemic cancer discipline. In considering the latest basic and clinical research developments in ocular oncogenesis and oncology, and providing the opportunity for cross-talk between ocular cancer biologists, systemic cancer biologists, ocular oncologists, systemic oncologists, patients, and patient advocates, the forum generated new knowledge and novel insights for the field. This report summarizes the content of the invited talks at the 2018 ARVO-Champalimaud Foundation Ocular Oncogenesis and Oncology Conference.

Role of Systemic High-Dose Methotrexate and Combined Approaches in the Management of Vitreoretinal Diffuse Large B-Cell Lymphoma: A Single Center Experience 1990-2018

Introduction. Vitreoretinal lymphoma (VRL) is a rare ocular malignancy. Diagnosis and optimal treatment remain a challenge for clinicians. We present clinical characteristics and outcome of a cohort of 69 patients affected by vitreoretinal diffuse large B-cell (DLBCL) lymphoma treated at Mayo Clinic over a 28-year period.Methods. We accessed the Mayo Clinic Lymphoma Data Base to identify all patients > 18 years old with VRL diagnosed between 01/01/1990 and 01/31/2018. Only patients with DLBCL, confirmed at pathological review, were included. Clinical characteristics, therapies, response, relapse patterns and follow up status were collected and analyzed in the cohort and in the different subgroups: primary (PVRL, localized only in eye at diagnosis) vs concurrent (CVRL) vs secondary VRL (SVRL). Chi-squared test, Fisher's exact test and Wilcoxon's signed-rank test were used for analysis. Failure-free survival (FFS), overall survival (OS), central nervous system (CNS) and eye relapse-free survival were analyzed according to Kaplan Meier method. Differences between subgroups were compared with log-rank test. Since the group of SVRL can be affected by a survivorship selection bias, it was investigated separately for the outcome analysis.Results. A total of 69 patients with vitreoretinal DLBCL were included. At diagnosis, 33 (48%) were PVRL, 18 (26%) CVRL (eye plus CNS (N=17) or systemic (N=1) disease) and 18 (26%) had SVRL (9 primary CNS lymphomas, 9 systemic at diagnosis, among which 4 were primary testicular lymphomas). Unilateral intraocular involvement was observed in 16 (23%) cases. Clinical characteristics are reported in Table I.At diagnosis, patients received a systemic treatment in 35 (50%, including high-dose systemic MTX (HD-MTX, N 14, 20%), MTR (HD-MTX, Temozolomide and Rituximab) (N 7, 10%) and CHOP (Cyclophosphamide, Doxorubicin, Vincristine and Prednisone) with or without Rituximab (N 10, 15%)), combined systemic plus intraocular treatment in 15 (22%), local radiotherapy in 10 (14%) and intraocular therapy (intraocular injections of rituximab or MTX or steroids or a combination of these) in 9 (13%) cases. Systemic Rituximab, autologous stem cell transplantation (ASCT) and therapeutic vitrectomy/enucleation were performed in 36 (53%), 20 (29%) and 5 (7%) patients, respectively. The median number of treatments was 2 (range 0-10). Among PVRL and CVRL (N=51), median FFS, CNS relapse-free survival, eye relapse-free survival and OS were: 1.8 y, 4.9 y, 3.8 y and 4.1 y, respectively (Fig 1). Among PVRL they were: 2.6 y, not reached (NR), 5.2 y and 9.3 y, respectively. No CNS relapse occurred beyond 4 years in the PVRL subgroup. The median OS for patients diagnosed between 1990 and 1999, in contrast to 2000 and 2018 was 1.5 y vs 9.4 y respectively (p= 0.0002). OS was significantly higher in PVRL, as compared to CVRL (p= 0.04). Previous immunosuppression and poor performance status were predictive of worse outcome (p=0.04), while ASCT correlated with higher OS (p= 0.009). In PVRL, a combined systemic + intraocular therapy was associated with higher FFS (p=0.002) and CNS-relapse free survival (p= 0.003), but no difference in OS was observed. Among 18 SVRL, at a median follow-up of 1.1 y after vitreoretinal relapse, median FFS and OS were 0.3 y and 1.3 y, respectively. Systemic toxicities included 8 (11.6%) acute renal failures, 8 (11.6%) infections, and 3 (4.3%) hemorrhages. Intraocular toxicities included cataract in 11, vitreal detachment in 3 , ocular hypertension in 5, retinal vessel occlusion in 3 and keratitis in 2 cases. Of 69 patients, 39 (56.5%) died secondary to lymphoma (N=21, 53.8%), infectious toxicity (N=2, 5.2%), unrelated (N=3, 7.7%) or unknown (N=13, 33.3%) causes.Conclusions. VR DLBCL is a rare disease, which can occur as primary, concurrent with systemic, or in relapsed disease. OS over the decades has significantly improved. In PVRL, no late CNS relapses were observed, while late intraocular relapses can occur. A combined approach with intraocular + systemic HD-MTX based treatment at diagnosis was associated with a higher FFS and CNS-relapse free survival in PVRL and is recommended in bilateral involvement, even though no differences in OS were observed. Treatment consolidation with ASCT can be considered in cases with concurrent systemic disease. Further studies are needed to confirm these results and to better define the role of new drugs in treatment of this uncommon malignancy. DisclosuresWitzig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Circular and long non-coding RNAs and their role in ophthalmologic diseases.

Long non-coding RNAs are 200 nucleotide long RNA molecules which lack or have limited protein-coding potential. They can regulate protein formation through several different mechanisms. Similarly, circular RNAs are reported to play a critical role in post-transcriptional gene regulation. Changes in the expression pattern of these molecules are established to underline various diseases, including cancer, cardiovascular, neurological and immunological disorders. Recent studies suggest that they are differentially expressed both in healthy ocular tissues as well as in eye pathologies, such as neovascularization, proliferative vitreoretinopathy, glaucoma, cataract, ocular malignancy or even strabismus. Aetiology of ocular diseases is multifactorial and combines genetic and environmental factors, including epigenetic and non-coding RNAs. In addition, disorders like diabetic retinopathy or age-related macular degeneration lack biomarkers for early detection as well as effective treatment methods that will allow controlling the disease progression at its early stages. The newly discovered non-coding RNAs seem to be the ideal candidate for novel molecular markers and therapeutic strategies. In this review, we summarize current knowledge about gene expression regulators - long non-coding and circular RNA molecules in eye diseases.

Transcription of the Human 5-Hydroxytryptamine Receptor 2B (HTR2B) Gene Is under the Regulatory Influence of the Transcription Factors NFI and RUNX1 in Human Uveal Melanoma.

Because it accounts for 70% of all eye cancers, uveal melanoma (UM) is therefore the most common primary ocular malignancy. In this study, we investigated the molecular mechanisms leading to the aberrant expression of the gene encoding the serotonin receptor 2B (HTR2B), one of the most discriminating among the candidates from the class II gene signature, in metastatic and non-metastatic UM cell lines. Transfection analyses revealed that the upstream regulatory region of the HTR2B gene contains a combination of alternative positive and negative regulatory elements functional in HTR2B− but not in HTR23B+ UM cells. We demonstrated that both the transcription factors nuclear factor I (NFI) and Runt-related transcription factor I (RUNX1) interact with regulatory elements from the HTR2B gene to either activate (NFI) or repress (RUNX1) HTR2B expression in UM cells. The results of this study will help understand better the molecular mechanisms accounting for the abnormal expression of the HTR2B gene in uveal melanoma.

Ocular and Periocular Tumors in Xeroderma Pigmentosum: A Study of 120 Asian Indian Patients

We studied the incidence, treatment, and outcome of ocular and periocular tumors in patients with xeroderma pigmentosum (XP). Retrospective case series. This single-institution study included 120 patients with XP who underwent intervention with excisional biopsy, enucleation, or orbital exenteration. The primary outcome measures were the occurrence of eyelid or ocular surface tumor, globe salvage, locoregional and systemic metastasis, and death. The mean age at presentation was 19 years. A family history of XP was present in 32 (27%) patients. Over a mean follow-up of 61months, 34 (28%) patients developed no ocular/adnexal tumor, 86 (72%) developed ocular surface malignancy, 15 (13%) developed eyelid malignancy, and 22 (18%) developed other head and neck malignancies. Of the 86 patients with ocular surface malignancy, 48 (56%) had unilateral tumor and 38 (44%) had bilateral tumors. Invasive squamous cell carcinoma (n= 51, 41%) was the most common ocular surface tumor. Of the 15 patients with eyelid tumors, 14 (93%) had unilateral tumor and 1 (7%) had bilateral involvement. Basal cell carcinoma (n= 8, 50%) was the most common eyelid tumor. There were events of ocular surface tumor recurrence (n= 55 eyes, 44%), eyelid tumor recurrence (n= 5 eyes, 31%), locoregional lymph node metastasis (n= 3, 2%), systemic metastasis (n= 1, 1%), and death (n= 1, 1%). Overall, globe salvage was achieved in 119 (99%) patients (both eyes were salvaged in 92 [76%] patients and at least 1 eye was salvaged in 27 [23%] patients). XP is frequently associated with ocular surface, eyelid, and other head and neck malignancies. Lifelong follow-up is mandatory in these patients.

Abstract 5157: ARF6 controls WNT5A receptor internalization to promote uveal melanoma invasion and metastasis

Abstract Introduction: Uveal melanoma is the most common primary ocular malignancy and there is currently no effective treatment for metastatic uveal melanoma largely because of the lack of understanding of the molecular mechanisms underlying this cancer. Although activating oncogenic mutations in GNAQ and GNA11 are present in 95% of uveal melanoma tumors, virtually nothing is known about the molecular mechanisms that drive oncogenesis in the remaining 5% of uveal melanomas that possess only wild type Gαq alleles and the molecular and cellular mechanisms that promote metastasis have not yet been discovered. This latter deficit in knowledge is extremely vexing, given that metastatic disease causes death in most uveal melanoma patients. We have recently shown that ADP-ribosylation factor 6 (ARF6), a small GTPase, is an immediate downstream effector of oncogenic Gαq and controls the entire major signaling pathways known to drive Gαq-mediated tumor formation and growth in uveal melanoma cells that have an activating mutation in Gαq. Moreover, in cutaneous melanoma, stimulation of the receptor by WNT5A activates ARF6 and controls metastasis via the release of β-catenin from N-cadherin and β-catenin's subsequent nuclear transport. Previous studies have also demonstrated that ARF6 plays a role in the internalization of various classes of membrane receptors including receptor tyrosine kinase (RTK) and G protein coupled receptor (GPCR) to control signal transduction, and WNT5A and its receptor promote tumor invasion and metastasis via receptor internalization in human cancers. Based on these intriguing findings, we postulate that ARF6 might be functioning to control tumor invasion and metastasis in uveal melanomas. Experimental Procedures: To test our hypothesis, we conducted cell invasion assays on uveal melanoma cell lines while targeting ARF6 expression by siRNA or ARF6 activity by pharmacological inhibition. We then proceeded with cell fractionation to look for any differences in the properties of subcellular components in treated cells compared to untreated cells. Unpublished findings: Here we show that WNT5A is expressed at high levels in Gαq wild type uveal melanoma cells and that WNT5A activates ARF6 through ROR2 receptor. When we block ARF6 expression by knockdown or ARF6 activity with a small molecule inhibitor, uveal melanoma invasion is significantly reduced. Notably, ARF6 is necessary for WNT5A-mediated ROR2 internalization. Conclusions: This work indicates that ARF6 functions in the internalization of WNT5A receptor to activate the signaling pathways that drive invasion and metastasis in uveal melanoma. These results would suggest that targeting ARF6 activation might be an effective therapy for the treatment of all uveal melanomas, regardless of their mutational status for Gαq. Citation Format: Donghan Shin, Coulson P. Rich, Lehi Acosta, Jackson R. Richards, Jae Hyuk Yoo, Allie H. Grossmann, Zongzhong Tong, Alan L. Mueller, Weiquan Zhu, Dean Y. Li, Shannon J. Odelberg. ARF6 controls WNT5A receptor internalization to promote uveal melanoma invasion and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5157.