Mutations in SAMD7 cause autosomal-recessive macular dystrophy with or without cone dysfunction.

Sterile alpha motif domain containing 7 (SAMD7) is a component of the Polycomb repressive complex 1, which inhibits transcription of many genes, including those activated by the transcription factor Cone-Rod Homeobox (CRX). Here we report bi-allelic mutations in SAMD7 as a cause of autosomal-recessive macular dystrophy with or without cone dysfunction. Four of these mutations affect splicing, while another mutation is a missense variant that alters the repressive effect of SAMD7 on CRX-dependent promoter activity, as shown by in vitro assays. Immunostaining of human retinal sections revealed that SAMD7 is localized in the nuclei of both rods and cones, as well as in those of cells belonging to the inner nuclear layer. These results place SAMD7 as a gene crucial for human retinal function and demonstrate a significant difference in the role of SAMD7 between the human and the mouse retina.

A Multicenter Study Validates the WHO 2022 Classification for Conjunctival Melanocytic Intraepithelial Lesions With Clinical and Prognostic Relevance.

Several nomenclature and grading systems have been proposed for conjunctival melanocytic intraepithelial lesions (C-MIL). The fourth "WHO Classification of Eye Tumors" (WHO-EYE04) proposed a C-MIL classification, capturing the progression of noninvasive neoplastic melanocytes from low- to high-grade lesions, onto melanoma in situ (MIS), and then to invasive melanoma. This proposal was revised to the WHO-EYE05 C-MIL system, which simplified the high-grade C-MIL, whereby MIS was subsumed into high-grade C-MIL. Our aim was to validate the WHO-EYE05 C-MIL system using digitized images of C-MIL, stained with hematoxylin and eosin and immunohistochemistry. However, C-MIL cases were retrieved from 3 supraregional ocular pathology centers. Adequate conjunctival biopsies were stained with hematoxylin and eosin, Melan-A, SOX10, and PReferentially expressed Antigen in Melanoma. Digitized slides were uploaded on the SmartZoom platform and independently scored by 4 ocular pathologists to obtain a consensus score, before circulating to 14 expert eye pathologists for independent scoring. In total, 105 cases from 97 patients were evaluated. The initial consensus diagnoses using the WHO-EYE04 C-MIL system were as follows: 28 benign conjunctival melanoses, 13 low-grade C-MIL, 37 high-grade C-MIL, and 27 conjunctival MIS. Using this system resulted in 93% of the pathologists showing only fair-to-moderate agreement (kappa statistic) with the consensus score. The WHO-EYE05 C-MIL system (with high-grade C-MIL and MIS combined) improved consistency between pathologists, with the greatest level of agreement being seen with benign melanosis (74.5%) and high-grade C-MIL (85.4%). Lowest agreements remained between pathologists for low-grade C-MIL (38.7%). Regarding WHO-EYE05 C-MIL scoring and clinical outcomes, local recurrences of noninvasive lesions developed in 8% and 34% of the low- and high-grade cases. Invasive melanoma only occurred in 47% of the cases that were assessed as high-grade C-MIL. This extensive international collaborative study is the first to undertake a comprehensive review of the WHO-EYE05 C-MIL scoring system, which showed good interobserver agreement and reproducibility.

When the second comes first- rhabdomyosarcoma preceding heritable retinoblastoma- a case report.

BACKGROUND: Retinoblastoma (rb) is the most frequent intraocular tumor, accounting for 3% of all childhood cancers. Heritable rb survivors are germline carriers for an RB1 mutation and have a lifelong risk to develop non-ocular second primary tumors (SPTs) involving multiple other organs like the bones, soft tissues, or skin. These SPTs usually become manifest several years succeeding the diagnosis of rb. In our instance, however, a non-ocular SPT presented prior to the diagnosis of heritable rb. CASE PRESENTATION: We report a rare case of a monozygotic twin who presented with primary rhabdomyosarcoma (RMS) preceding the manifestation of heritable rb. The rb was diagnosed when the child developed strabismus while already on therapy for the RMS. The child underwent therapy for both as per defined treatment protocols. The rb regressed well on treatment, but the RMS relapsed and the child developed multiple refractory metastatic foci and succumbed to his disease. CONCLUSIONS: Non-ocular SPTs like sarcomas are usually known to manifest in heritable rb survivors with a lag of two to three decades (earlier if exposure to radiation is present) from the presentation of the rb. However, in our case, this seemed to be reversed with the RMS being manifest at an unusual early age and the rb being diagnosed at a later point in time.

Translational screening platform to evaluate chemotherapy in combination with focal therapy for retinoblastoma.

Retinoblastoma is the most common pediatric eye cancer. It is currently treated with a limited number of drugs, adapted from other pediatric cancer treatments. Drug toxicity and relapse of the disease warrant new therapeutic strategies for these young patients. In this study, we developed a robust tumoroid-based platform to test chemotherapeutic agents in combination with focal therapy (thermotherapy) - a treatment option widely used in clinical practice - in accordance with clinically relevant trial protocols. The model consists of matrix-embedded tumoroids that retain retinoblastoma features and respond to repeated chemotherapeutic drug exposure similarly to advanced clinical cases. Moreover, the screening platform includes a diode laser (810 nm, 0.3 W) to selectively heat the tumoroids, combined with an on-line system to monitor the intratumoral and surrounding temperatures. This allows the reproduction of the clinical settings of thermotherapy and combined chemothermotherapy treatments. When testing the two main drugs currently used in clinics to treat retinoblastoma in our model, we observed results similar to those clinically obtained, validating the utility of the model. This screening platform is the first system to accurately reproduce clinically relevant treatment methods and should lead to the identification of more efficient drugs to treat retinoblastoma.

Genomic and transcriptomic landscape of conjunctival melanoma.

Conjunctival melanoma (CJM) is a rare but potentially lethal and highly-recurrent cancer of the eye. Similar to cutaneous melanoma (CM), it originates from melanocytes. Unlike CM, however, CJM is relatively poorly characterized from a genomic point of view. To fill this knowledge gap and gain insight into the genomic nature of CJM, we performed whole-exome (WES) or whole-genome sequencing (WGS) of tumor-normal tissue pairs in 14 affected individuals, as well as RNA sequencing in a subset of 11 tumor tissues. Our results show that, similarly to CM, CJM is also characterized by a very high mutation load, composed of approximately 500 somatic mutations in exonic regions. This, as well as the presence of a UV light-induced mutational signature, are clear signs of the role of sunlight in CJM tumorigenesis. In addition, the genomic classification of CM proposed by TCGA seems to be well-applicable to CJM, with the presence of four typical subclasses defined on the basis of the most frequently mutated genes: BRAF, NF1, RAS, and triple wild-type. In line with these results, transcriptomic analyses revealed similarities with CM as well, namely the presence of a transcriptomic subtype enriched for immune genes and a subtype enriched for genes associated with keratins and epithelial functions. Finally, in seven tumors we detected somatic mutations in ACSS3, a possible new candidate oncogene. Transfected conjunctival melanoma cells overexpressing mutant ACSS3 showed higher proliferative activity, supporting the direct involvement of this gene in the tumorigenesis of CJM. Altogether, our results provide the first unbiased and complete genomic and transcriptomic classification of CJM.

Fingolimod and tumor-infiltrating lymphocytes in checkpoint-inhibitor treated cancer patients.

Immune checkpoint inhibitors (ICIs) are emerging as the new standard of care for treating various metastatic cancers. It is known that effective anti-tumor immune responses are associated with a stronger presence of tumor-infiltrating lymphocytes (TILs) in solid tumor tissue. Cancer patients with relapsing-remitting multiple sclerosis (RRMS) are often under continuous treatment with fingolimod, an immune-modulating drug that inhibits lymphocyte egress from secondary lymphatic organs. Little is known about the effect of fingolimod on ICI cancer therapy, as fingolimod may limit the number of TILs. Here we present three patients with RRMS, who developed various cancers during fingolimod treatment. Histology of all tumors consistently showed low numbers of TILs. A second biopsy taken from one of the tumors, a melanoma, revealed a significant increase of TILs after stopping fingolimod and starting pembrolizumab, indicating a surge in the number and re-invigoration of T cells. Our study suggests that fingolimod limits the number of TILs in solid tumors and may, thus, inhibit anti-cancer immune responses.

Glial cells of the human fovea.

Purpose: The exact cellular types that form the human fovea remain a subject of debate, and few studies have been conducted on human macula to solve this question. The purpose of this study was to perform immunohistochemistry on fresh human samples to characterize the glial cells that form the human fovea. Methods: Immunohistochemistry was performed using antibodies against proteins expressed in astrocytes or in retinal Müller glial cells or both types of cells on six human macula obtained from eyes enucleated for peripheral intraocular tumors and on two postmortem eyes from healthy donors. The posterior poles of the enucleated eyes were cryosectioned and stained with antibodies against the glial proteins GFAP, vimentin, CRALBP, glutamine synthetase, and connexin 43. Results: A population of cells positive for GFAP and negative for glutamine synthetase and CRALBP that express connexin 43 were identified at the roof of the foveal pit. These cells are distinct from the Müller cone cells described by Yamada and Gass, suggesting that another type of foveal glial cells, most likely astrocytes, are present in the human fovea. Conclusions: This study showed that in humans, astrocytic glial cells cover the foveal pit. Their roles in macula homeostasis and mechanisms of macular diseases disease remain to be determined.

Comprehensive Genetic Landscape of Uveal Melanoma by Whole-Genome Sequencing.

Uveal melanoma (UM) is a rare intraocular tumor that, similar to cutaneous melanoma, originates from melanocytes. To gain insights into its genetics, we performed whole-genome sequencing at very deep coverage of tumor-control pairs in 33 samples (24 primary and 9 metastases). Genome-wide, the number of coding mutations was rather low (only 17 variants per tumor on average; range 7-28), thus radically different from cutaneous melanoma, where hundreds of exonic DNA insults are usually detected. Furthermore, no UV light-induced mutational signature was identified. Recurrent coding mutations were found in the known UM drivers GNAQ, GNA11, BAP1, EIF1AX, and SF3B1. Other genes, i.e., TP53BP1, CSMD1, TTC28, DLK2, and KTN1, were also found to harbor somatic mutations in more than one individual, possibly indicating a previously undescribed association with UM pathogenesis. De novo assembly of unmatched reads from non-coding DNA revealed peculiar copy-number variations defining specific UM subtypes, which in turn could be associated with metastatic transformation. Mutational-driven comparison with other tumor types showed that UM is very similar to pediatric tumors, characterized by very few somatic insults and, possibly, important epigenetic changes. Through the analysis of whole-genome sequencing data, our findings shed new light on the molecular genetics of uveal melanoma, delineating it as an atypical tumor of the adult for which somatic events other than mutations in exonic DNA shape its genetic landscape and define its metastatic potential.

Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects.

Cone-rod degeneration (CRD) belongs to the disease spectrum of retinal degenerations, a group of hereditary disorders characterized by an extreme clinical and genetic heterogeneity. It mainly differentiates from other retinal dystrophies, and in particular from the more frequent disease retinitis pigmentosa, because cone photoreceptors degenerate at a higher rate than rod photoreceptors, causing severe deficiency of central vision. After exome analysis of a cohort of individuals with CRD, we identified biallelic mutations in the orphan gene CEP78 in three subjects from two families: one from Greece and another from Sweden. The Greek subject, from the island of Crete, was homozygous for the c.499+1G>T (IVS3+1G>T) mutation in intron 3. The Swedish subjects, two siblings, were compound heterozygotes for the nearby mutation c.499+5G>A (IVS3+5G>A) and for the frameshift-causing variant c.633delC (p.Trp212Glyfs(∗)18). In addition to CRD, these three individuals had hearing loss or hearing deficit. Immunostaining highlighted the presence of CEP78 in the inner segments of retinal photoreceptors, predominantly of cones, and at the base of the primary cilium of fibroblasts. Interaction studies also showed that CEP78 binds to FAM161A, another ciliary protein associated with retinal degeneration. Finally, analysis of skin fibroblasts derived from affected individuals revealed abnormal ciliary morphology, as compared to that of control cells. Altogether, our data strongly suggest that mutations in CEP78 cause a previously undescribed clinical entity of a ciliary nature characterized by blindness and deafness but clearly distinct from Usher syndrome, a condition for which visual impairment is due to retinitis pigmentosa.

Sostdc1 is expressed in all major compartments of developing and adult mammalian eyes.

PURPOSE: This study was conducted in order to study Sostdc1 expression in rat and human developing and adult eyes. METHODS: Using the yeast signal sequence trap screening method, we identified the Sostdc1 cDNA encoding a protein secreted by the adult rat retinal pigment epithelium. We determined by in situ hybridization, RT-PCR, immunohistochemistry, and western blot analysis Sostdc1 gene and protein expression in developing and postnatal rat ocular tissue sections. We also investigated Sostdc1 immunohistolocalization in developing and adult human ocular tissues. RESULTS: We demonstrated a prominent Sostdc1 gene expression in the developing rat central nervous system (CNS) and eyes at early developmental stages from E10.5 days postconception (dpc) to E13 dpc. Specific Sostdc1 immunostaining was also detected in most adult cells of rat ocular tissue sections. We also identified the rat ocular embryonic compartments characterized by a specific Sostdc1 immunohistostaining and specific Pax6, Sox2, Otx2, and Vsx2 immunohistostaining from embryonic stages E10.5 to E13 dpc. Furthermore, we determined the localization of SOSTDC1 immunoreactivity in ocular tissue sections of developing and adult human eyes. Indeed, we detected SOSTDC1 immunostaining in developing and adult human retinal pigment epithelium (RPE) and neural retina (NR) as well as in several developing and adult human ocular compartments, including the walls of choroidal and scleral vessels. Of utmost importance, we observed a strong SOSTDC1 expression in a pathological ocular specimen of type 2 Peters' anomaly complicated by retinal neovascularization as well in the walls ofother pathological extra-ocular vessels.  CONCLUSION: As rat Sostdc1 and human SOSTDC1 are dual antagonists of the Wnt/ß-catenin and BMP signaling pathways, these results underscore the potential crucial roles of these pathways and their antagonists, such as Sostdc1 and SOSTDC1, in developing and adult mammalian normal eyes as well as in syndromic and nonsyndromic congenital eye diseases.

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR FOR THE MANAGEMENT OF NEOVASCULARIZATION IN RETINOBLASTOMA AFTER INTRAVENOUS AND/OR INTRAARTERIAL CHEMOTHERAPY: Long-Term Outcomes in a Series of 35 Eyes.

PURPOSE: To report the use of anti-vascular endothelial growth factor in the management of retinoblastoma. METHODS: Retrospective review of 35 eyes (33 patients) treated with at least one intravitreal anti-vascular endothelial growth factor (ranibizumab and/or aflibercept) for new iris (n = 26) and/or retinal neovascularization (n = 21) after intravenous chemotherapy and/or intraarterial chemotherapy. RESULTS: Most eyes (n = 31/35, 89%) were Group D or E. Previous treatments were salvage intraarterial chemotherapy after intravenous chemotherapy (n = 21/35, 60%), first-line intraarterial chemotherapy (n = 7/35, 20%), and first-line intravenous chemotherapy (n = 7/35, 20%). Associated clinical features were retinal ischemia (94%), retinal detachment (51%), active tumor (34%), intravitreal hemorrhage (43%), and/or glaucoma (17%). Mean 1.6 anti-vascular endothelial growth factor injections/eye were given; 28 eyes received ranibizumab, 2 aflibercept, and 5 both agents. Eight eyes underwent complementary treatments of ischemic retina. Resolution of neovascularization was observed in 28 eyes (n = 28/35, 80%). Globe salvage was achieved in 51% (n = 18/35), including 25% of those with active tumor (n = 3/12). One eye became phthisic. Sixteen eyes were enucleated, nine for tumor relapse/progression. Five eyes had high-risk histopathologic risk factors and received adjuvant intravenous chemotherapy. All patients are alive with no extraocular extension nor metastases (mean follow-up 3.7 years, range 1.1-7.6). CONCLUSION: Intravitreal anti-vascular endothelial growth factor contributed to a globe salvage rate of 51% by providing conditions to continue conservative treatment.

Cone Genesis Tracing by the Chrnb4-EGFP Mouse Line: Evidences of Cellular Material Fusion after Cone Precursor Transplantation.

The cone function is essential to mediate high visual acuity, color vision, and daylight vision. Inherited cone dystrophies and age-related macular degeneration affect a substantial percentage of the world population. To identify and isolate the most competent cells for transplantation and integration into the retina, cone tracing during development would be an important added value. To that aim, the Chrnb4-EGFP mouse line was characterized throughout retinogenesis. It revealed a sub-population of early retinal progenitors expressing the reporter gene that is progressively restricted to mature cones during retina development. The presence of the native CHRNB4 protein was confirmed in EGFP-positive cells, and it presents a similar pattern in the human retina. Sub-retinal transplantations of distinct subpopulations of Chrnb4-EGFP-expressing cells revealed the embryonic day 15.5 high-EGFP population the most efficient cells to interact with host retinas to provoke the appearance of EGFP-positive cones in the photoreceptor layer. Importantly, transplantations into the DsRed retinas revealed material exchanges between donor and host retinas, as >80% of transplanted EGFP-positive cones also were DsRed positive. Whether this cell material fusion is of significant therapeutic advantage requires further thorough investigations. The Chrnb4-EGFP mouse line definitely opens new research perspectives in cone genesis and retina repair.

SUBFOVEAL NODULE IN COATS' DISEASE: Toward an Updated Classification Predicting Visual Prognosis.

PURPOSE: To determine the prevalence, clinical characteristics and nature of subfoveal nodules in Coats' disease and the associated impact on the long-term visual outcome. METHODS: Consecutive cases of Coats' disease with foveal exudation were retrospectively reviewed. The presence of a subfoveal nodule or macular fibrosis was recorded. Clinical characteristics, retinal imaging, and outcome were analyzed by comparative analysis. The histopathological description of an enucleated eye with subfoveal nodule was performed. RESULTS: Among 40 patients presenting unilateral Stage 2B or 3A1 Coats' disease, a subfoveal nodule was detected in 21 patients (52.5%). The median follow-up was 4.7 years. Nineteen patients (47.5%) did not present a subfoveal nodule. Three patients (15.8%) without subfoveal nodule and 21 patients (100%) with subfoveal nodule progressed to a macular fibrotic scar (P < 0.0001), and the mean time of macular fibrosis onset was 11.0 ± 2.6 months. Final visual acuity was significantly worse in patients who presented a subfoveal nodule at diagnosis (P = 0.01). Of 18 cases with subfoveal nodule who underwent fluorescein angiography, retinal-retinal anastomosis and neovascularization were detected in 13 (72.2%) and 2 eyes (11.1%), respectively. Histopathological analysis of a subfoveal nodule revealed an aggregate of proteinaceous material including fibrin, spindle cells, macrophages, and pigmented cells. CONCLUSION: The presence of a subfoveal nodule at presentation is a predictive factor for macular fibrosis development and worse visual outcome in patients with Coats' disease. These observations suggest an updated classification introducing two subcategories within Stage 2B: without subfoveal nodule (Stage 2B1) and with subfoveal nodule (Stage 2B2).

Ocular adnexal (orbital) solitary fibrous tumor: nuclear STAT6 expression and literature review.

PURPOSE: To report the clinico-pathological features of solitary fibrous tumor occurring in the ocular adnexa (OA) in a single center. To assess the presence of NAB2-STAT6 genes fusion in OA solitary fibrous tumor detected by nuclear overexpression of STAT6. METHODS: Retrospective study including orbital and OA solitary fibrous tumors treated between 2006 and 2014 in our center. The clinical, radiological, and histopathological findings were evaluated. STAT6 expression was assessed by immunohistochemistry. RESULTS: Five patients were identified and presented with a chronic OA mass. The tumors were radiologically well delimited, highly vascularized and without bone erosion. All the patients underwent complete surgical excision. Pathological examination confirmed solitary fibrous tumor in all cases. All tumors demonstrated a nuclear expression of STAT6. There were no recurrences, with a mean follow-up of 5 years after surgery. Our review demonstrated that proptosis was the most common presentation occurring in 60 % of the cases. In the ocular adnexa, adverse histological criteria were found in 19.7 % of the tumors, and recurrences were observed in 48 % of these cases. Thirty-six percent of patients presented at least one local recurrence, and metastastic spread was found in 2.4 % of the cases. Tumor-related death was described in two cases. CONCLUSION: Ocular adnexal SFT are rare and usually present as a chronic orbital mass with proptosis. In the OA, solitary fibrous tumor demonstrates STAT6 nuclear expression, as documented in other locations. Recurrences are unusual and metastasis exceptional. Initial surgical resection should be complete in order to avoid recurrence.