Regulation of epigenetic homeostasis in uveal melanoma and retinoblastoma

Recent updates on drug delivery approaches for improved ocular delivery with an insight into nanostructured drug delivery carriers for anterior and posterior segment disorders

Ocular diseases have a major impact on patient's vision and quality of life, with approximately 2.2 billion people have visual impairment worldwide according to the findings from the World Health Organization (WHO). The eye is a complex organ with unique morphology and physiology consisting of numerous ocular barriers which hinders the entry of exogenous substances and impedes drug absorption. This in turn has a substantial impact on effective drug delivery to treat ocular diseases, especially intraocular disorders which has consistently presented a challenge to eye care professionals. The most common method of delivering medications to the eye is topical instillation of eye drops. Although this approach is a viable option for treating many ocular diseases remains a major challenge for the effective treatment of posterior ocular conditions. Up till now, incessant efforts have been committed to design innovative drug delivery systems with the hopes of potential clinical application. Modern developments in nanocarrier's technology present a potential chance to overcome these obstacles by enabling targeted delivery of the loaded medication to the eyes with improved solubility, delayed release, higher penetration and increased retention. This review covers the anatomy of eye with associated ocular barriers, ocular diseases and administration routes. In addition it primarily focuses on the latest progress and contemporary applications of ophthalmic formulations providing specific insight on nanostructured drug delivery carriers reported over the past 5 years highlighting their values in achieving efficient ocular drug delivery to both anterior and posterior segments. Most importantly, we outlined in this review the macro and nanotechnology based ophthalmic drug formulations that are being patented or marketed so far for treating ocular diseases. Finally, based on current trends and therapeutic concepts, we highlighted the challenges faced by novel ocular drug delivery systems and provided prospective future developments for further research in these directions. We hope that this review will serve as a source of motivation and ideas for formulation scientists in improving the design of innovative ophthalmic formulations.

Lactylation-boosted polycomb repression of KLF4 elicits glycolysis in retinoblastoma: A positive feedback circuit between histone modifications

The perturbation of histone modification homeostasis is a hallmark of oncogene activation and tumor suppressor gene silencing. Howbeit, the intricate interplay among diverse histone modifications in the context of tumorigenesis is not fully understood. Herein, we unveil a positive feedback mechanism involving lactylation and methylation of histones, which is instrumental in the oncogenic progression of retinoblastoma. First, we pinpointed that the selective upregulation of SUZ12 leads to the upregulation of H3K27me3 modification in retinoblastoma, which is attributed to heightened levels of histone lactylation. Notably, the targeted suppression of SUZ12 has demonstrated significant therapeutic benefits in both in vitro and in vivo models of retinoblastoma. Furthermore, multi-omics analysis has identified Krüppel-like factor 4 (KLF4) as a key downstream effector of SUZ12. Mechanistically, SUZ12 is implicated in the enhancement of the H3K27me3 mark on the KLF4 promoter, thereby repressing its transcription. Intriguingly, the downregulation of KLF4 is associated with an upregulation of glycolysis and a concomitant accumulation of the onco-metabolite lactate, which in turn augments histone lactylation. In conclusion, we provide novel insights into the intricate interplay between lactylation and methylation of histones, shedding light on the epigenetic-metabolic reprogramming that underlies oncogene activation and tumor suppressor gene inactivation in cancer.

RNA methylation homeostasis in ocular diseases: All eyes on Me

RNA methylation is a pivotal epigenetic modification that adjusts various aspects of RNA biology, including nuclear transport, stability, and the efficiency of translation for specific RNA candidates. The methylation of RNA involves the addition of methyl groups to specific bases and can occur at different sites, resulting in distinct forms, such as N6-methyladenosine (m6A), N1-methyladenosine (m1A), 5-methylcytosine (m5C), and 7-methylguanosine (m7G). Maintaining an optimal equilibrium of RNA methylation is crucial for fundamental cellular activities such as cell survival, proliferation, and migration. The balance of RNA methylation is linked to various pathophysiological conditions, including senescence, cancer development, stress responses, and blood vessel formation, all of which are pivotal for comprehending a spectrum of eye diseases. Recent findings have highlighted the significant role of diverse RNA methylation patterns in ophthalmological conditions such as age-related macular degeneration, diabetic retinopathy, cataracts, glaucoma, uveitis, retinoblastoma, uveal melanoma, thyroid eye disease, and myopia, which are critical for vision health. This thorough review endeavors to dissect the influence of RNA methylation on common and vision-impairing ocular disorders. It explores the nuanced roles that RNA methylation plays in key pathophysiological mechanisms, such as oxidative stress and angiogenesis, which are integral to the onset and progression of these diseases. By synthesizing the latest research, this review offers valuable insights into how RNA methylation could be harnessed for therapeutic interventions in the field of ophthalmology.

Epigenetics of Conjunctival Melanoma: Current Knowledge and Future Directions

The purpose of this article is to provide a literature review of the epigenetic understanding of conjunctival melanoma (CM), with a primary focus on current gaps in knowledge and future directions in research. CM is a rare aggressive cancer that predominantly affects older adults. Local recurrences and distant metastases commonly occur in CM patients; however, their prediction and management remain challenging. Hence, there is currently an unmet need for useful biomarkers and more effective treatments to improve the clinical outcomes of these patients. Like other cancers, CM occurrence and prognosis are believed to be influenced by multiple genetic and epigenetic factors that contribute to tumor development/progression/recurrence/spread, immune evasion, and primary/acquired resistance to therapies. Epigenetic alterations may involve changes in chromatin conformation/accessibility, post-translational histone modifications or the use of histone variants, changes in DNA methylation, alterations in levels/functions of short (small) or long non-coding RNAs (ncRNAs), or RNA modifications. While recent years have witnessed a rapid increase in available epigenetic technologies and epigenetic modulation-based treatment options, which has enabled the development/implementation of various epi-drugs in the cancer field, the epigenetic understanding of CM remains limited due to a relatively small number of epigenetic studies published to date. These studies primarily investigated DNA methylation, ncRNA (e.g., miRNA or circRNA) expression, or RNA methylation. While these initial epigenetic investigations have revealed some potential biomarkers and/or therapeutic targets, they had various limitations, and their findings warrant replication in independent and larger studies/samples. In summary, an in-depth understanding of CM epigenetics remains largely incomplete but essential for advancing our molecular knowledge and improving clinical management/outcomes of this aggressive disease.

PRMT1 mediates the proliferation of Y79 retinoblastoma cells by regulating the p53/p21/CDC2/cyclin B pathway

Retinoblastoma (RB) is the most common intraocular malignancy among children and presents a certain mortality risk, especially in low- and middle-income countries. Clarifying the molecular mechanisms underlying the onset and progression of retinoblastoma is vital for devising effective cancer treatment approaches. PRMT1, a major type I PRMT, plays significant roles in cancer development. However, its expression and role in retinoblastoma are still unclear. Our research revealed a marked increase in PRMT1 levels in both retinoblastoma tissues and Y79 cells. The overexpression of PRMT1 in Y79 cells promoted their growth and cell cycle progression. Conversely, the suppression of PRMT1 hindered the growth of Y79 cells and impeded cell cycle progression. Mechanistically, PRMT1 mediated the growth of Y79 retinoblastoma cells by targeting the p53/p21/CDC2/Cyclin B pathway. Additionally, the ability of PRMT1 knockdown to suppress cell proliferation was also observed in vivo. Overall, PRMT1 could function as a potential target for therapeutic treatment in individuals with retinoblastoma.

Gain of chromosome 8q and high expression of EZH2 may predict poor prognosis in Chinese patients with uveal melanoma

PURPOSE

To explore risk factors predicting poor prognosis of uveal melanoma in a Chinese population, with specific emphasis on monosomy 3, 8q gain, and EZH2 staining.

METHODS

Eighty-nine patients with uveal melanoma from 2012 to 2021 were reviewed. Clinical and pathological records were collected and analyzed. Immunohistochemical staining of EZH2, monosomy 3 and 8q gain were respectively conducted in 45, 54, and 57 cases. Survival was evaluated by Kaplan-Meier analysis and log-rank test. Cox proportional hazard regressions were employed to predict risk factors of distant metastasis.

RESULTS

The median follow-up was 44 months. Altogether, 16 % of patients developed distant metastases and died from disease-related causes. Disease-specific survival at one and three years was 96.6 % and 88.4 % while distant metastasis rates were 7.9 % and 12 %. Univariate Cox regression analysis revealed that age (HR: 1.04), tumor largest basal diameter (HR: 1.21), tumor thickness (HR: 1.21), ciliary body involvement (HR: 3.50), AJCC stage (HR: 5.68), epithelioid cell type (HR: 7.71), 8q gain (HR: 7.48), and high expression of EZH2 (HR: 6.09) were associated with distant metastasis. 8q gain was associated with epithelioid cell type and thicker tumor while EZH2 was correlated with epithelioid cell type. Monosomy 3 lacked a significant correlation with other factors.

CONCLUSION

EZH2 and 8q gain could be taken into consideration when calculating poor prognosis in Chinese patients with uveal melanoma. Monosomy 3 showed no significance in distant metastasis, but this may be due to a small sample size.

RBMS1 reflects a distinct microenvironment and promotes tumor progression in ocular melanoma

Ocular melanoma, including uveal melanoma (UM) and conjunctival melanoma (CM), is the most common ocular cancer among adults with a high rate of recurrence and poor prognosis. Loss of epigenetic homeostasis disturbed gene expression patterns, resulting in oncogenesis. Herein, we comprehensively analyzed the DNA methylation, transcriptome profiles, and corresponding clinical information of UM patients through multiple machine-learning algorithms, finding that a methylation-driven gene RBMS1 was correlated with poor clinical outcomes of UM patients. RNA-seq and single-cell RNA-seq analyses revealed that RBMS1 reflected diverse tumor microenvironments, where high RBMS1 expression marked an immune active TME. Furthermore, we found that tumor cells were identified to have the higher communication probability in RBMS1+ state. The functional enrichment analysis revealed that RBMS1 was associated with pigment granule and melanosome, participating in cell proliferation as well as apoptotic signaling pathway. Biological experiments were performed and demonstrated that the silencing of RBMS1 inhibited ocular melanoma proliferation and promoted apoptosis. Our study highlighted that RBMS1 reflects a distinct microenvironment and promotes tumor progression in ocular melanoma, contributing to the therapeutic customization and clinical decision-making.

Epigenetics research in eye diseases: a bibliometric analysis from 2000 to 2023

CLINICAL RELEVANCE

A bibliometric analysis is a quantitative study that utilises methods such as citation analysis to evaluate research performance. A bibliometric analysis could provide a valuable reference for ophthalmic researchers to understand the trends in epigenetics research.

BACKGROUND

The number of studies on epigenetics in eye diseases has exceeded 5,000, but the progress and scope of epigenetic research on eye diseases remain unclear. The study aimed to bibliometrically analyse epigenetic research conducted in eye diseases.

METHODS

Studies concerning epigenetic research on eye diseases from 2000-2023 were searched using the Web of Science Core Collection. Following this, the included studies were analysed for citations, journals, keywords, authors, and countries, using the Bibliometrix package in R Studio.

RESULTS

In total, 3758 studies were included in the analysis, including 3099 original articles, 599 reviews, 11 editorials, and 49 early access articles. Investigative Ophthalmology & Visual Science was the most published journal with 185 articles, and Proceedings of the National Academy of Sciences of the United States of America was the most cited journal, with 8727 citations. The journal with the highest h-index was Oncogene (h-index = 38).Renu A Kowluru from the Kresge Eye Institute, Wayne State University, Detroit, USA, had the most citations with 1,690 and the highest h-index (h-index = 23). China and the USA were the countries with the highest number of publications (1739) and total citations (40533), respectively. Furthermore, from 2000-2023, the top five frequent research topics were diabetic retinopathy, 522; microribonucleic acid, 469; retinoblastoma, 370; apoptosis, 268; and epigenetics, 206.

CONCLUSIONS

The results of this bibliometric study provide the current status and trends of epigenetic research in eye diseases and will help researchers identify areas of current interest in the field, which should help highlight new research directions.

Combination of Molecule-Targeted Therapy and Photodynamic Therapy Using Nanoformulated Verteporfin for Effective Uveal Melanoma Treatment

Uveal melanoma (UM) is the most common primary ocular malignancy in adults and has high mortality. Recurrence, metastasis, and therapeutic resistance are frequently observed in UM, but no beneficial systemic therapy is available, presenting an urgent need for developing effective therapeutic drugs. Verteporfin (VP) is a photosensitizer and a Yes-Associated Protein (YAP) inhibitor that has been used in clinical practice. However, VP's lack of tumor targetability, poor biocompatibility, and relatively low treatment efficacy hamper its application in UM management. Herein, we developed a biocompatible CD44-targeting hyaluronic acid nanoparticle (HANP) carrying VP (HANP/VP) to improve UM treatment efficacy. We found that HANP/VP showed a stronger inhibitory effect on cell proliferation than that of free VP in UM cells. Systemic delivery of HANP/VP led to targeted accumulation in the UM-tumor-bearing mouse model. Notably, HANP/VP mediated photodynamic therapy (PDT) significantly inhibited UM tumor growth after laser irradiation compared with no treatment or free VP treatment. Consistently, in HANP/VP treated tumors after laser irradiation, the tumor proliferation and YAP expression level were decreased, while the apoptotic tumor cell and CD8+ immune cell levels were elevated, contributing to effective tumor growth inhibition. Overall, the results of this preclinical study showed that HANP/VP is an effective nanomedicine for tumor treatment through PDT and inhibition of YAP in the UM tumor mouse model. Combining phototherapy and molecular-targeted therapy offers a promising approach for aggressive UM management.

Etiology including epigenetic defects of retinoblastoma

Retinoblastoma (RB), originating from the developing retina, is an aggressive intraocular malignant neoplasm in childhood. Biallelic loss of RB1 is conventionally considered a prerequisite for initiating RB development in most RB cases. Additional genetic mutations arising from genome instability following RB1 mutations are proposed to be required to promote RB development. Recent advancements in high throughput sequencing technologies allow a deeper and more comprehensive understanding of the etiology of RB that additional genetic alterations following RB1 biallelic loss are rare, yet epigenetic changes driven by RB1 loss emerge as a critical contributor promoting RB tumorigenesis. Multiple epigenetic regulators have been found to be dysregulated and to contribute to RB development, including noncoding RNAs, DNA methylations, RNA modifications, chromatin conformations, and histone modifications. A full understanding of the roles of genetic and epigenetic alterations in RB formation is crucial in facilitating the translation of these findings into effective treatment strategies for RB. In this review, we summarize current knowledge concerning genetic defects and epigenetic dysregulations in RB, aiming to help understand their links and roles in RB tumorigenesis.

An observation study of the effect of "Internet + Nursing" on psychological status and quality of life of patients with thyroid eye disease

"Internet + Nursing" refers to medical institutions using Internet technologies and big data to provide nursing services to discharged patients or those with severe illnesses unable to visit hospitals, through online applications and offline care provision. This study aimed to explore the influence of "Internet + Nursing" on the psychological status and quality of life of patients with thyroid eye disease. Sixty-eight patients with thyroid eye disease from January 2021 to December 2022 were divided into a research group (n = 34, joined the platform) and control group (n = 34, not joined the platform) based on their voluntary participation in our hospital's "Internet + Nursing Platform." The self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores of the research group were lower than those of the control group (P < .05). The short form-36 health survey (SF-36) scores in various dimensions were higher in the research group compared to the control group (P < .05). The incidence rates of retinal detachment, vitreous hemorrhage, diabetic retinopathy, and iris neovascularization were lower in the research group compared to the control group (P < .05). After nursing, exophthalmos, blink frequency, and eyelid height of the research group were lower than those of the control group, while tear film breakup time was higher than that of the control group (P < .05). The visual acuity of the research group was higher than that of the control group (P < .05). After nursing, the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) scores in various dimensions were significantly higher in the research group than those in the control group (P < .05). Additionally, after nursing, the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) in the research group were lower than those in the control group (P < .05). The patients in the research group exhibited higher recognition scores of nursing compared to those in the control group (P < .05). Through the implementation of "Internet + Nursing" for patients with thyroid eye disease discharged from our hospital, we can provide better out-of-hospital nursing for patients, reduce the occurrence of complications, improve ocular surface symptoms, promote visual acuity recovery, and improve patients' psychological status and quality of life.

Light-responsive polymeric nanoparticles for retinal drug delivery: design cues, challenges and future perspectives

A multitude of sight-threatening retinal diseases, affecting hundreds of millions around the globe, lack effective pharmacological treatments due to ocular barriers and common drug delivery limitations. Polymeric nanoparticles (PNPs) are versatile drug carriers with sustained drug release profiles and tunable physicochemical properties which have been explored for ocular drug delivery to both anterior and posterior ocular tissues. PNPs can incorporate a wide range of drugs and overcome the challenges of conventional retinal drug delivery. Moreover, PNPs can be engineered to respond to specific stimuli such as ultraviolet, visible, or near-infrared light, and allow precise spatiotemporal control of the drug release, enabling tailored treatment regimens and reducing the number of required administrations. The objective of this study is to emphasize the therapeutic potential of light-triggered drug-loaded polymeric nanoparticles to treat retinal diseases through an exploration of ocular pathologies, challenges in drug delivery, current production methodologies and recent applications. Despite challenges, light-responsive PNPs hold the promise of substantially enhancing the treatment landscape for ocular diseases, aiming for an improved quality of life for patients.

Histone lactylation bridges metabolic reprogramming and epigenetic rewiring in driving carcinogenesis: Oncometabolite fuels oncogenic transcription

Heightened lactate production in cancer cells has been linked to various cellular mechanisms such as angiogenesis, hypoxia, macrophage polarisation and T-cell dysfunction. The lactate-induced lactylation of histone lysine residues is noteworthy, as it functions as an epigenetic modification that directly augments gene transcription from chromatin. This epigenetic modification originating from lactate effectively fosters a reliance on transcription, thereby expediting tumour progression and development. Herein, this review explores the correlation between histone lactylation and cancer characteristics, revealing histone lactylation as an innovative epigenetic process that enhances the vulnerability of cells to malignancy. Moreover, it is imperative to acknowledge the paramount importance of acknowledging innovative therapeutic methodologies for proficiently managing cancer by precisely targeting lactate signalling. This comprehensive review illuminates a crucial yet inadequately investigated aspect of histone lactylation, providing valuable insights into its clinical ramifications and prospective therapeutic interventions centred on lactylation.

Recent progress in retinoblastoma: Pathogenesis, presentation, diagnosis and management

Retinoblastoma, the primary ocular malignancy in pediatric patients, poses a substantial threat to mortality without prompt and effective management. The prognosis for survival and preservation of visual acuity hinges upon the disease severity at the time of initial diagnosis. Notably, retinoblastoma has played a crucial role in unraveling the genetic foundations of oncogenesis. The process of tumorigenesis commonly begins with the occurrence of biallelic mutation in the RB1 tumor suppressor gene, which is then followed by a cascade of genetic and epigenetic alterations that correspond to the clinical stage and pathological features of the tumor. The RB1 gene, recognized as a tumor suppressor, encodes the retinoblastoma protein, which plays a vital role in governing cellular replication through interactions with E2F transcription factors and chromatin remodeling proteins. The diagnosis and treatment of retinoblastoma necessitate consideration of numerous factors, including disease staging, germline mutation status, family psychosocial factors, and the resources available within the institution. This review has systematically compiled and categorized the latest developments in the diagnosis and treatment of retinoblastoma which enhanced the quality of care for this pediatric malignancy.

The Potential of Aqueous Humor Sampling in Diagnosis, Prognosis, and Treatment of Retinoblastoma

Retinoblastoma (RB) is a rare malignant tumor that arises in the developing retina in one or both eyes of children. Pathogenic variants of the RB1 tumor suppressor gene drive the majority of germline and sporadic RB tumors. Considering the risk of tumor spread, the biopsy of RB tumor tissue is contraindicated. Advancement of chemotherapy has led to preservation of more eye globes. However, this has reduced access to tumor material from enucleation specimens. Recently, liquid biopsy of aqueous humor (AH) has advanced the RB tumor- or eye-specific genetic analysis. In particular, nucleic acid analysis of AH demonstrates the genomic copy number profiles and RB1 pathogenic variants akin to that of enucleated RB eye tissue. This advance reduces the previous limitation that genetic assessment of the primary tumor could be done only after enucleation of the eye. Additionally, nucleic acid evaluation of AH allows the exploration of the genomic landscape of RB tumors at diagnosis and during and after treatment. This review explores how AH sampling and AH nucleic acid analysis in RB patients assist in diagnosis, prognosis, and comprehending the pathophysiology of RB, which will ultimately benefit individualized treatment decisions to carefully manage this ocular cancer in children.

Targeting histone deacetylase suppresses tumor growth through eliciting METTL14-modified m6 A RNA methylation in ocular melanoma

BACKGROUND

Diversified histone deacetylation inhibitors (HDACis) have demonstrated encouraging outcomes in multiple malignancies. N6-methyladenine (m6 A) is the most prevalent messenger RNA modification that plays an essential role in the regulation of tumorigenesis. Howbeit, an in-depth understanding of the crosstalk between histone acetylation and m6 A RNA modifications remains enigmatic. This study aimed to explore the role of histone acetylation and m6 A modifications in the regulation of tumorigenesis of ocular melanoma.

METHODS

Histone modification inhibitor screening was used to explore the effects of HDACis on ocular melanoma cells. Dot blot assay was used to detect the global m6 A RNA modification level. Multi-omics assays, including RNA-sequencing, cleavage under targets and tagmentation, single-cell sequencing, methylated RNA immunoprecipitation-sequencing (meRIP-seq), and m6 A individual nucleotide resolution cross-linking and immunoprecipitation-sequencing (miCLIP-seq), were performed to reveal the mechanisms of HDACis on methyltransferase-like 14 (METTL14) and FAT tumor suppressor homolog 4 (FAT4) in ocular melanoma. Quantitative real-time polymerase chain reaction (qPCR), western blotting, and immunofluorescent staining were applied to detect the expression of METTL14 and FAT4 in ocular melanoma cells and tissues. Cell models and orthotopic xenograft models were established to determine the roles of METTL14 and FAT4 in the growth of ocular melanoma. RNA-binding protein immunoprecipitation-qPCR, meRIP-seq, miCLIP-seq, and RNA stability assay were adopted to investigate the mechanism by which m6 A levels of FAT4 were affected.

RESULTS

First, we found that ocular melanoma cells presented vulnerability towards HDACis. HDACis triggered the elevation of m6 A RNA modification in ocular melanoma. Further studies revealed that METTL14 served as a downstream candidate for HDACis. METTL14 was silenced by the hypo-histone acetylation status, whereas HDACi restored the normal histone acetylation level of METTL14, thereby inducing its expression. Subsequently, METTL14 served as a tumor suppressor by promoting the expression of FAT4, a tumor suppressor, in a m6 A-YTH N6-methyladenosine RNA-binding protein 1-dependent manner. Taken together, we found that HDACi restored the histone acetylation level of METTL14 and subsequently elicited METTL14-mediated m6 A modification in tumorigenesis.

CONCLUSIONS

These results demonstrate that HDACis exert anti-cancer effects by orchestrating m6 A modification, which unveiling a "histone-RNA crosstalk" of the HDAC/METTL14/FAT4 epigenetic cascade in ocular melanoma.

Intravenous versus super-selected intra-arterial chemotherapy in children with advanced unilateral retinoblastoma: an open-label, multicentre, randomised trial

BACKGROUND

Super-selected intra-arterial chemotherapy has increasingly been used as conservative management for retinoblastoma during the past decade. However, the absence of evidence from randomised controlled trials engendered controversy in the administration route of chemotherapy. We aimed to assess the efficacy and safety of intra-arterial chemotherapy compared with intravenous chemotherapy.

METHODS

This open-label, multicentre, randomised trial was done at six hospitals in China. Patients with new-onset unilateral group D or E retinoblastoma (poorly defined, large, or very large tumours, according to the International Intraocular Retinoblastoma Classification) without high-risk clinical factors were included. Patients were randomly assigned (1:1) to receive intra-arterial chemotherapy (injections of 0·5 mg/kg [or depending on age] melphalan with 20 mg carboplatin [first and third cycles] or with 1 mg topotecan [second and fourth cycles]) or intravenous chemotherapy (0·05 mg/kg [or 1·5 mg/m2] vincristine, 5 mg/kg [or 150 mg/m2] etoposide, and 18·6 mg/kg [or 560 mg/m2] carboplatin for six cycles). After intra-arterial chemotherapy, patients received a subcutaneous injection of 0·1 mL nadroparin calcium twice at a 12 h interval. Both intra-arterial and intravenous chemotherapy cycles were completed every 4 weeks. No masking was done, except of independent statisticians, who were masked to the allocation information. The primary outcome was 2-year progression-free globe salvage rate, defined as the time from randomisation to tumour progression or enucleation, whichever occurred first, and was analysed by intention to treat. We also recorded predefined safety outcomes (myelosuppression and ophthalmic arterial stenosis or occlusion) and severe adverse events likely to be related to study treatment. The study is registered with the Chinese Clinical Trial Registry, ChiCTR-IPR-15006469, and is complete.

FINDINGS

Between June 1, 2015, and June 1, 2018, 234 patients with newly diagnosed retinoblastoma were screened and 143 eligible patients (median age 23·6 months [IQR 14·0-31·9]) were enrolled and randomly assigned to the intra-arterial chemotherapy group (n=72) or the intravenous chemotherapy group (n=71). At a median follow-up of 35·8 months (IQR 28·4-43·0), the 2-year progression-free globe salvage rate was 53% (38 of 72 patients) in the intra-arterial chemotherapy group and 27% (19 of 71 patients) in the intravenous chemotherapy group (risk ratio 1·97, 95% CI 1·27-3·07, p=0·0020). Myelosuppression was less common in the intra-arterial chemotherapy group than in the intravenous chemotherapy group (37 [51%] of 72 patients vs 50 [70%] of 71 patients; 0·73, 95% CI 0·56-0·96, p=0·021) and less severe (ptrend=0·0070). In the intra-arterial chemotherapy group, two (3%) of 72 patients had ophthalmic artery occlusion and 13 (18%) patients had ophthalmic artery stenosis.

INTERPRETATION

Our findings show that intra-arterial chemotherapy could significantly improve the globe salvage rate in children with advanced unilateral retinoblastoma compared with intravenous chemotherapy, with mild systemic complications and no difference in overall survival rate. Intra-arterial chemotherapy could be an acceptable first-line treatment in children with advanced unilateral retinoblastoma.

FUNDING

Scientific Research Program of the National Health and Family Planning Commission of China, the Clinical Research Plan of Shanghai Hospital Development Center, the National Natural Science Foundation of China, and the Science and Technology Commission of Shanghai Municipality.

NSUN2-mediated m5 C RNA methylation dictates retinoblastoma progression through promoting PFAS mRNA stability and expression

BACKGROUND

The precise temporal and spatial regulation of N⁵ -methylcytosine (m⁵ C) RNA modification plays essential roles in RNA metabolism, and is necessary for the maintenance of epigenome homeostasis. Howbeit, the mechanism underlying the m⁵ C modification in carcinogenesis remains to be fully addressed.

METHODS

Global and mRNA m⁵ C levels were determined by mRNA isolation and anti-m⁵ C dot blot in both retinoblastoma (RB) cells and clinical samples. Orthotopic intraocular xenografts were established to examine the oncogenic behaviours of RB. Genome-wide multiomics analyses were performed to identify the functional target of NSUN2, including proteomic analysis, transcriptome screening and m⁵ C-methylated RNA immunoprecipitation sequencing (m⁵ C-meRIP-seq). Organoid-based single-cell analysis and gene-correlation analysis were performed to verify the NSUN2/ALYREF/m⁵ C-PFAS oncogenic cascade.

RESULTS

Herein, we report that NSUN2-mediated m⁵ C RNA methylation fuels purine biosynthesis during the oncogenic progression of RB. First, we discovered that global and mRNA m⁵ C levels were significantly enriched in RBs compared to normal retinas. In addition, tumour-specific NSUN2 expression was noted in RB samples and cell lines. Therapeutically, targeted correction of NSUN2 exhibited efficient therapeutic efficacy in RB both in vitro and in vivo. Through multiomics analyses, we subsequently identified phosphoribosylformylglycinamidine synthase (PFAS), a vital enzyme in purine biosynthesis, as a downstream candidate target of NSUN2. The reintroduction of PFAS largely reversed the inhibitory phenotypes in NSUN2-deficient RB cells, indicating that PFAS was a functional downstream target of NSUN2. Mechanistically, we found that the m⁵ C reader protein ALYREF was responsible for the recognition of the m⁵ C modification of PFAS, increasing its expression by enhancing its RNA stability.

CONCLUSIONS

Conclusively, we initially demonstrated that NSUN2 is necessary for oncogenic gene activation in RB, expanding the current understanding of dynamic m⁵ C function during tumour progression. As the NSUN2/ALYREF/m⁵ C-PFAS oncogenic cascade is an important RB trigger, our study suggests that a targeted m⁵ C reprogramming therapeutic strategy may be a novel and efficient anti-tumour therapy approach.

Single cell sequencing analysis constructed the N7-methylguanosine (m7G)-related prognostic signature in uveal melanoma

BACKGROUND

Uveal melanoma is a highly malignant tumor in the eye. Its recurrence and metastasis are common, and the prognosis is poor.

METHODS

The transcriptome data of UVM were downloaded from TCGA database, and the single cell sequencing dataset GSE139829 was downloaded from GEO database. Weighted co-expression network analysis was used to explore the modules associated with m7G. Lasso regression was used to construct M⁷G-related prognostic signature. Immune infiltration analysis was used to explore the significance of the model in the tumor immune microenvironment. Finally, cell assays were used to explore the function of key genes in the MUM-2B and OCM-1 cell lines of UVM.

RESULTS

The prognostic signature was constructed by Cox regression and Lasso regression. Patients could be divided into high-risk group and low-risk group by this signature, and the high-risk group had worse prognosis (P<0.05). Cell experiments showed that the proliferation, invasion and migration ability of UVM cell lines were significantly decreased after the knockdown of PAG1, a key gene in signature, which proved that PAG1 might be a potential target of UVM.

CONCLUSIONS

Our study explored the significance of m⁷G in UVM, provided biomarkers for its diagnosis and treatment.

Polymer- and lipid-based nanocarriers for ocular drug delivery: Current status and future perspectives

Ocular diseases seriously affect patients' vision and life quality, with a global morbidity of over 43 million blindness. However, efficient drug delivery to treat ocular diseases, particularly intraocular disorders, remains a huge challenge due to multiple ocular barriers that significantly affect the ultimate therapeutic efficacy of drugs. Recent advances in nanocarrier technology offer a promising opportunity to overcome these barriers by providing enhanced penetration, increased retention, improved solubility, reduced toxicity, prolonged release, and targeted delivery of the loaded drug to the eyes. This review primarily provides an overview of the progress and contemporary applications of nanocarriers, mainly polymer- and lipid-based nanocarriers, in treating various eye diseases, highlighting their value in achieving efficient ocular drug delivery. Additionally, the review covers the ocular barriers and administration routes, as well as the prospective future developments and challenges in the field of nanocarriers for treating ocular diseases.

Novel insights into histone lysine methyltransferases in cancer therapy: From epigenetic regulation to selective drugs

The reversible and precise temporal and spatial regulation of histone lysine methyltransferases (KMTs) is essential for epigenome homeostasis. The dysregulation of KMTs is associated with tumor initiation, metastasis, chemoresistance, invasiveness, and the immune microenvironment. Therapeutically, their promising effects are being evaluated in diversified preclinical and clinical trials, demonstrating encouraging outcomes in multiple malignancies. In this review, we have updated recent understandings of KMTs' functions and the development of their targeted inhibitors. First, we provide an updated overview of the regulatory roles of several KMT activities in oncogenesis, tumor suppression, and immune regulation. In addition, we summarize the current targeting strategies in different cancer types and multiple ongoing clinical trials of combination therapies with KMT inhibitors. In summary, we endeavor to depict the regulation of KMT-mediated epigenetic landscape and provide potential epigenetic targets in the treatment of cancers.

Retinoblastoma: Review and new insights

Retinoblastoma (Rb), the most frequent malignant intraocular tumor in childhood, is caused by mutations in the retinoblastoma gene (RB1) situated on chromosome 13q14.2. The incidence of retinoblastoma is approximately 1 in 17,000 live births with approximately 8,000 new cases diagnosed each year worldwide. Rb is the prototypical hereditary cancer in humans. Autosomal dominant inheritance is seen in 30-40% of cases whereas the non-inherited sporadic type accounts for the remaining 60-70%. Rb arises due to inactivation of both alleles of the Rb tumor suppressor gene, which results in a defective Rb protein (pRB) with subsequent cell cycle impairment and uncontrolled cell proliferation. Patients with Rb have survival rates higher than 95-98% in industrialized countries but mortality remains high in developing countries. For example, the mortality rate in Africa is 70%. In all cases of intraocular and extraocular retinoblastoma, there is a need for new therapies that are more effective and carry less risk of toxicity. The Bruckner test is a practical and easy test for the detection of Rb, this test consists of assessing the fundus reflex through the pupil (red reflex) in both eyes simultaneously with a bright coaxial light produced with the direct ophthalmoscope. Rb can be detected by the Bruckner test showing a pupil that shines white or “Leukocoria”. Although the diagnosis of Rb remains essentially clinical, the newly identified biomarkers could contribute to early molecular detection, timely detection of micrometastases and establish new therapeutic options for Rb.

Current understanding of epigenetics role in melanoma treatment and resistance

Melanoma is the most aggressive form of skin cancer resulting from genetic mutations in melanocytes. Several factors have been considered to be involved in melanoma progression, including genetic alteration, processes of damaged DNA repair, and changes in mechanisms of cell growth and proliferation. Epigenetics is the other factor with a crucial role in melanoma development. Epigenetic changes have become novel targets for treating patients suffering from melanoma. These changes can alter the expression of microRNAs and their interaction with target genes, which involves cell growth, differentiation, or even death. Given these circumstances, we conducted the present review to discuss the melanoma risk factors and represent the current knowledge about the factors related to its etiopathogenesis. Moreover, various epigenetic pathways, which are involved in melanoma progression, treatment, and chemo-resistance, as well as employed epigenetic factors as a solution to the problems, will be discussed in detail.

Recent Advances and Challenges in Uveal Melanoma Immunotherapy

Simple Summary

Uveal melanoma is the most common primary intraocular malignancy in adults. Although it can be controlled locally, half of the patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Existing therapies, such as chemotherapy and targeted therapies, induce only minimal responses. This review focuses on newly published research on immunotherapy. We highlight expanding treatments and their clinical outcomes, as well as propose promising new treatments and feasible checkpoints. Based on these findings, we provide innovative insights into feasible strategies for the treatment of patients with uveal melanoma.

Abstract

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Compared to cutaneous melanoma (CM), which mainly harbors BRAF or NRAS mutations, UM predominantly harbors GNAQ or GNA11 mutations. Although primary UM can be controlled locally, approximately 50% of patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Unfortunately, chemotherapy and targeted therapies only induce minimal responses in patients with metastatic UM, with a median survival time of only 4–5 months after metastasis detection. Immunotherapy agents, such as immune checkpoint inhibitors, have achieved pioneering outcomes in CM but have shown limited effects in UM. Researchers have explored several feasible checkpoints to identify options for future therapies. Cancer vaccines have shown little in the way of therapeutic benefit in patients with UM, and there are few ongoing trials providing favorable evidence, but adoptive cell transfer-related therapies seem promising and deserve further investigation. More recently, the immune-mobilizing monoclonal T-cell receptor against the cancer molecule tebentafusp showed impressive antitumor effects. Meanwhile, oncolytic viruses and small molecule inhibitors have also gained ground. This review highlights recent progress in burgeoning treatments and provides innovative insights on feasible strategies for the treatment of UM.

Genome maintenance in retinoblastoma: Implications for therapeutic vulnerabilities (Review)

Retinoblastoma (RB) is a pediatric ocular malignancy that is initiated mostly by biallelic inactivation of the RB transcriptional corepressor 1 (RB1) tumor suppressor gene in the developing retina. Unlike the prevailing prediction based on multiple studies involving RB1 gene disruption in experimental models, human RB tumors have been demonstrated to possess a relatively stable genome, characterized by a low mutation rate and a few recurrent chromosomal alterations related to somatic copy number changes. This suggests that RB may harbor heightened genome maintenance mechanisms to counteract or compensate for the risk of massive genome instability, which can potentially be driven by the early RB1 loss as a tumor-initiating event. Although the genome maintenance mechanisms might have been evolved to promote RB cell survival by preventing lethal genomic defects, emerging evidence suggests that the dependency of RB cells on these mechanisms also exposes their unique vulnerability to chemotherapy, particularly when the genome maintenance machineries are tumor cell-specific. This review summarizes the genome maintenance mechanisms identified in RB, including findings on the roles of chromatin regulators in DNA damage response/repair and protein factors involved in maintaining chromosome stability and promoting survival in RB. In addition, advantages and challenges for exploiting these therapeutic vulnerabilities in RB are discussed.

Applications of Non-Coding RNAs in Patients With Retinoblastoma

Retinoblastoma (RB) is the most common primary intraocular malignancy in childhood. In the carcinogenic process of neoplasms such as RB, the role of non-coding RNAs (ncRNAs) has been widely demonstrated recently. In this review, we aim to provide a clinical overview of the current knowledge regarding ncRNAs in relation to RB. Although ncRNAs are now considered as potential diagnostic biomarkers, prognostic factors, and therapeutic targets, further studies will facilitate enhanced understanding of ncRNAs in RB physiopathology and define the roles ncRNAs can play in clinical practice.