FOXD1 Is a Transcription Factor Important for Uveal Melanocyte Development and Associated with High-Risk Uveal Melanoma

Simple Summary

Despite successful treatment of primary uveal melanoma (UM), metastases still occur in approximately 50% of the patients. Unfortunately, little is known about the mechanism behind metastasized UM. By reanalyzing publicly available single-cell RNA sequencing data of embryonic zebrafish larvae and validating the results with UM data, we have identified five transcription regulators of interest: ELL2, KDM5B, REXO4, RBFOX2 and FOXD1. The most significant finding is FOXD1, which is nearly exclusively expressed in high-risk UM and is associated with poor survival. FOXD1 is a novel gene which could be involved in the metastatic capability of UM. Elucidating its function and role in metastatic UM could help to understand and develop treatment for UM.

Abstract

Uveal melanoma (UM) is a deadly ocular malignancy, originating from uveal melanocytes. Although much is known regarding prognostication in UM, the exact mechanism of metastasis is mostly unknown. Metastatic tumor cells are known to express a more stem-like RNA profile which is seen often in cell-specific embryonic development to induce tumor progression. Here, we identified novel transcription regulators by reanalyzing publicly available single cell RNA sequencing experiments. We identified five transcription regulators of interest: ELL2, KDM5B, REXO4, RBFOX2 and FOXD1. Our most significant finding is FOXD1, as this gene is nearly exclusively expressed in high-risk UM and its expression is associated with a poor prognosis. Even within the BAP1-mutated UM, the expression of FOXD1 is correlated with poor survival. FOXD1 is a novel factor which could potentially be involved in the metastatic capacity of high-risk UM. Elucidating the function of FOXD1 in UM could provide insight into the malignant transformation of uveal melanocytes, especially in high-risk UM.

Identification of Early-Onset Metastasis in SF3B1 Mutated Uveal Melanoma

Simple Summary

This study describes clinical and genetic characteristics of the largest aggregated cohort of Splicing Factor 3 Subunit B1 (SF3B1)-mutated Uveal Melanoma (UM) in the literature (n = 146). Missense mutations in the spliceosome gene SF3B1 result in an altered splice site recognition and aberrant mRNA transcripts. The SF3B1-mutated UM show early- and late-onset of metastatic disease for which, currently, no distinguishing biomarkers exist. Using a cutoff of 60 months for stratification, we found that a largest basal tumor diameter was more prevalent in the early-onset metastatic disease group. Furthermore, using differential gene expression and the detection of aberrant transcripts, we found that the expression of alpha/beta-Hydrolase domain containing 6 (ABHD6) is associated with early-onset metastatic SF3B1 and aberrant transcripts that are associated with early-onset SF3B1-mutated UM. Our results provide more accurate prognostication and targets for future functional studies in an effort to elucidate pathogenesis of SF3B1-mutated UM.

Abstract

Approximately 25% of all uveal melanoma (UM) contain driver mutations in the gene encoding the spliceosome factor SF3B1, and whilst patients with such SF3B1 mutations generally have an intermediate risk on developing metastatic disease, a third of these patients develop early metastasis within 5 years after diagnosis. We therefore investigated whether clinical and/or genetic variables could be indicative of short progression-free survival (PFS < 60 months) or long PFS (PFS ≥ 60 months) for SF3B1-mutated (SF3B1^mut) UM patients. We collected 146 SF3B1^mut UM from our Rotterdam Ocular Melanoma Studygroup (ROMS) database and external published datasets. After stratification of all SF3B1^mut UM using short PFS vs. long PFS, only largest tumor diameter (LTD) was significantly larger (mean: 17.7 mm (±2.8 SD) in the short PFS SF3B1^mut group vs. the long PFS group (mean: 14.7 (±3.7 SD, p = 0.001). Combined ROMS and The Cancer Genome Atlas (TCGA) transcriptomic data were evaluated, and we identified SF3B1^mut-specific canonical transcripts (e.g., a low expression of ABHD6 indicative for early-onset metastatic disease) or distinct expression of SF3B1^mut UM aberrant transcripts, indicative of early- or late-onset or no metastatic SF3B1^mut UM.

Impact of Obstructive Sleep Apnea on Optic Nerve Function in Patients With Craniosynostosis and Recurrent Intracranial Hypertension

PURPOSE

Assessment of combined impact of intracranial hypertension (ICH) and obstructive sleep apnea (OSA) on optic nerve function in children with craniosynostosis (CS).

DESIGN

Retrospective cross-sectional study.

METHODS

Patients treated at Boston Children's Hospital for CS who had an ophthalmic examination that included pattern reversal (pr)VEP (2013-2014) and history of ICH based on direct measurement, papilledema, or classic features on neuroimaging and during cranial vault expansion were included. History of OSA was determined by polysomnography and associated conditions, including apnea and (adeno)tonsillectomy. Subjects were divided into 4 groups: group 1, resolved ICH absent history of OSA; group 2, resolved ICH with history of OSA; group 3, recurrent ICH absent history of OSA; and group 4, recurrent ICH with history of OSA. Predictor variables included latency of P100 component of pattern-reversal visual evoked potential, best-corrected visual acuity, optic nerve appearance, visual fields, and global retinal nerve fiber layer. Primary outcome was association of prolonged P100 latency with resolved vs recurrent ICH and OSA.

RESULTS

Twenty-eight children met inclusion criteria (mean age 11.6 ± 6.9 years): group 1 (n = 3), group 2 (n = 6), group 3 (n = 8), and group 4 (n = 11). P100 latencies were not prolonged in groups 1 and 2. Three of 8 in group 3 and 9 of 11 in group 4 had prolonged P100 latency. Group 4 was significantly worse than group 3 (P = .005).

CONCLUSIONS

History of OSA, in addition to recurrent ICH, is associated with greatest risk of optic neuropathy with CS. Ophthalmologists should encourage early management of OSA as well as ICH to optimize ophthalmic outcomes.

Can Robin Sequence Be Predicted From Prenatal Ultrasonography?

PURPOSE

Prenatal diagnosis of Robin sequence (RS) could promote safe delivery and improve perinatal care. The purpose of this study was to evaluate the correlation between prenatal ultrasonography (US) and magnetic resonance imaging (MRI) studies for assessing micrognathia to determine if US alone can be used to reliably screen for RS.

MATERIALS AND METHODS

This was a retrospective case-control study of fetuses evaluated in the Advanced Fetal Care Center at Boston Children's Hospital from 2002 to 2017. To be included, 1) prenatal MRI and US must have been performed during the same visit, 2) the infant must have been live-born, and 3) the diagnosis must have been confirmed postnatally. Patients with images of inadequate quality for analysis were excluded. Patients were divided into 4 groups based on postnatal diagnosis: 1) RS (micrognathia, glossoptosis, and airway obstruction) (RS group), 2) micrognathia without RS (micrognathia group), 3) cleft lip and palate (CLP) without micrognathia (CLP group), and 4) gestational age-matched controls with normal craniofacial morphology (control group). The inferior facial angle (IFA) was measured using both imaging modalities and compared. Receiver operating characteristic curves were applied to identify a threshold for the diagnosis of RS from US. The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio were calculated.

RESULTS

A total of 94 patients were included (mean gestational age at imaging, 24.9 ± 5.2 weeks), with 25 in the RS group (26.6%), 29 in the micrognathia group (30.9%), 23 in the CLP group (24.5%), and 17 in the control group (18.1%). The IFA was significantly smaller in the RS group than in all other groups on both US and MRI (P < .001). A moderate correlation was found between IFA measurements on US and MRI (intraclass correlation coefficient, 0.729). An IFA threshold on US of 45.5° maximized sensitivity (84%) and specificity (81%) for the diagnosis of RS.

CONCLUSIONS

We suggest incorporating the IFA into routine prenatal US and referring patients for confirmatory MRI when the US IFA is lower than 45.5°.