S-Adenosylmethionine Inhibits the Proliferation of Retinoblastoma Cell Y79, Induces Apoptosis and Cell Cycle Arrest of Y79 Cells by Inhibiting the Wnt2/ß-Catenin Pathway.

Retinoblastoma is one of the most common primary intraocular malignancies in young children. Traditional treatment methods such as chemotherapy often come with significant adverse effects, such as hearing loss, cognitive impairment, and vision loss. Therefore, there is an urgent need to explore a novel therapeutic drug that is both effective and safe. S-adenosylmethionine (SAM) is a natural compound known to exhibit anti-proliferative effects in various cancer cell lines. However, to date, no studies investigated the effects of SAM on retinoblastoma cells and its potential mechanisms of action. Therefore, this study aims to investigate the impact of SAM on retinoblastoma cells and explore its possible mechanisms of action, with the hope of providing new insights into the treatment of this disease. The optimal concentration of SAM was determined using the Cell Counting Kit-8 assay. The effect of SAM on retinoblastoma proliferation was assessed using the 5-ethynyl-2'-deoxyuridine cell proliferation assay. Y79 cells were subjected to hematoxylin and eosin stain and electron microscopy to observe any morphological changes induced by SAM. The stages of SAM's action on the retinoblastoma cell cycle and its apoptotic effects were measured using flow cytometry. The apoptotic effect of SAM on retinoblastoma was further confirmed using the TUNEL assay. Differential expression of related genes was detected through RT-PCR. In vivo subcutaneous tumor formation in nude mice and immunohistochemistry were employed to validate the effect of SAM on retinoblastoma-related phenotypes. Western blotting was conducted to investigate whether SAM modulated retinoblastoma-related phenotypes via the Wnt2/ß-catenin pathway. SAM arrested the cell cycle of retinoblastoma at the G1 phase, induced apoptosis of retinoblastoma cells through the Wnt2/ß-catenin pathway, and affected their morphology and even ultrastructure. In addition, in vitro and in vivo experiments demonstrated that SAM had an oncogenic effect on retinoblastoma. In this study, we verify in vitro and in vivo whether SAM inhibits the proliferation of retinoblastoma cell Y7, induces apoptosis and cell cycle arrest of Y79 cells by inhibiting the Wnt2/ß-catenin pathway, and affects the morphology and structure of retinoblastoma cell Y79.

Saúde alerta sobre a importância do diagnóstico precoce do retinoblastoma

Nesta quarta-feira (18), dia em que se lembra a importância do diagnóstico precoce do retinoblastoma, o Ministério da Saúde chama a atenção dos pais e responsáveis a ficarem atentos aos primeiros sinais da doença. O retinoblastoma é um tumor maligno originário das células da retina, que é a parte do olho responsável pela visão, afetando um ou ambos os olhos. É o mais comum tumor maligno intraocular da infância e geralmente ocorre antes dos 5 anos de idade. Pode ocorrer de forma esporádica (70 a 75% dos casos) ou hereditária (25 a 30% dos casos).

[Metachronous bilateral retinoblastoma: a case report].

The patient is a 2-year-old male. The family consulted the Department of Ophthalmology, Shanghai Ninth People's Hospital, after noticing a white reflection in the pupil area of the child's right eye for 6 days. Following a thorough ocular and systemic examination, the patient was diagnosed with retinoblastoma (Group E, cT2bN0M0) of the right eye. The right eye was enucleated and classified as pathological stage pT3cN0M0. Postoperatively, systemic intravenous chemotherapy with the VEC regimen was administered. Genetic testing revealed a germline mutation in the RB1 gene: c.874 (exon9) delT (p.Tyr292fsTer9), necessitating close monitoring of the socket during follow-up visits. Three months after the operation, fundus examination revealed yellow-white lesions in the left eye, and bilateral retinoblastoma was diagnosed (Group E in the right eye, Group C in the left eye). Based on the ICRB and pTNM stages, the patient underwent six rounds of systemic intravenous chemotherapy and three rounds of cryotherapy in the left eye. No recurrence was detected with a 4-year follow-up. The patient was initially diagnosed with unilateral retinoblastoma, but later developed the disease in the contralateral eye during treatment, which was a case of metachronous bilateral retinoblastoma.

Risk of alterations in neurodevelopment in infants and preschool children with cancer.

BACKGROUND: Some cancer survivors experience difficulties with concentration, attention, and memory; however, there are no studies on neurodevelopment in patients under 5 years of age who are undergoing cancer treatment. Our aim was to evaluate neurodevelopment in cancer patients under 5 years of age using the Early Development Instrument (EDI) test, considering factors such as nutritional status, type of cancer, and treatment effect. METHODS: A cross-sectional study was conducted from February 2018 to March 2019. Patients with cancer diagnoses outside the central nervous system in any phase of cancer treatment were included. RESULTS: A total of 45 patients were included. Regarding fine motor skills, 28% of patients with retinoblastoma and 23% of patients with leukemia or lymphoma had a risk of developmental delay compared to 0% of patients with solid tumors (p = 0.025). The final results showed that 19 (42.2%) patients had normal neurodevelopment (gray), 7 (15.5%) had a delay in neurodevelopment (light gray), and 19 (42.2%) had a risk of developmental delay (black). Regarding developmental delay, 52% of patients in the leukemia and lymphoma group, 71% in the retinoblastoma group, and 23% in the solid tumor group presented developmental delay (p = 0.06). CONCLUSIONS: The risk of delay and lag in neurodevelopment is common in cancer patients under 5 years of age undergoing treatment. However, more studies are required to evaluate the effect of treatment on this group of patients as it may be affected by various factors.

INTRODUCCIÓN: En algunos pacientes supervivientes de cáncer se presentan dificultades de concentración, atención y memoria, sin embargo no hay estudios en relación al neurodesarrollo en pacientes menores de 5 años que se encuentran en tratamiento oncológico. Por lo que el objetivo fue valorar el neurodesarrollo en pacientes con cáncer durante el tratamiento oncológico mediante la prueba EDI tomando en cuenta diversos factores como su estado nutricional, tipo de cancer, y el efecto del tratamiento. MÉTODOS: Se realizó un estudio transversal, de febrero de 2018 a marzo de 2019. Se incluyeron pacientes mayores de 1 año y menores de 5 años con diagnóstico de cáncer fuera del sistema nervioso central, en tratamiento oncológico. RESULTADOS: Se incluyeron 45 pacientes. En el área motor fina el 28% de los pacientes con retinoblastoma y 23% con leucemias y linfomas se encontraron en rojo (retraso) en comparación con 0% de los pacientes con tumores sólidos (p = 0.025). En el resultado global se encontró que 19 (42.2%) pacientes tuvieron neurodesarrollo normal (gris), 7 (15.5%) rezago en el neurodesarrollo (gris claro) y 19 (42.2%) con riesgo de retraso en el desarrollo (negro). De los pacientes que presentaron riesgo de retraso el 52% fueron del grupo de leucemias y linfomas, el 71% en el grupo de retinoblastoma y el 23% del grupo de tumores sólidos (p = 0.06). CONCLUSIONES: La presencia de riesgo de retraso y rezago en el neurodesarrollo es frecuente en menores de 5 años con diagnóstico de cáncer. Se requieren más estudios, para evaluar el efecto del tratamiento en este grupo de pacientes, ya que pueden influir diversos factores.

Retinoblastoma in Ceara: An epidemiological study in a Brazilian pediatric oncology referral center.

PURPOSE: Although Brazil has a high prevalence of retinoblastoma, there is a lack of epidemiological data on the disease. Thus, in this study, we aimed to evaluate the epidemiological profile of patients diagnosed with retinoblastoma in the ophthalmology department of a pediatric tertiary referral hospital in Ceara, Brazil. METHODS: A descriptive and cross-sectional study was conducted by retrospectively analyzing the clinical and socioeconomic data from the medical records of pediatric patients followed-up at the hospital between 2007 and 2021. Retinoblastoma was diagnosed on the basis of a fundoscopic or histopathologic examination. RESULTS: The data of 105 patients were included in the study, and the mean patient age at the time of diagnosis was 1.7 years. Most of the patients were women (50.5%) and hailed from rural areas (57.4%), which was associated with a higher tumor stage. Of the 150 patients, 57.1% initially presented with leukocoria. Ocular hyperemia was associated with more advanced stages of retinoblastoma (p=0.004). Bilateral involvement was observed in 25.7% of the patients and at a significantly younger age (p=0.009). The presence of retinal detachment, vascularized lesions, and vitreous seeds significantly increased the likelihood of requiring enucleation. DISCUSSION: This study presents an epidemiological description of retinoblastoma in Brazil, which highlights the significance of early detection. Delayed diagnosis is associated with a poorer visual prognosis and higher mortality rate, particularly in patients with unilateral disease. Risk factors for a more severe disease were retinal detachment, vascularized lesions, and vitreous seeds. The correlation between histopathological features and clinical outcomes was limited. CONCLUSION: Further studies are required to assess the influence of ocular hyperemia, fundoscopic assessment, and histopathologic findings on the prognosis of retinoblastoma. Moreover, it is critical to devise interventions to reduce the time-to-diagnosis in rural areas.

Quality of life of Retinoblastoma survivors in tertiary care eye hospital in South India.

PURPOSE: With the increased survival of retinoblastoma (RB) patients, it is important to evaluate the quality of life (QoL) of RB survivors as well as caregivers to provide comprehensive care to the children and caregivers. This study aims to assess the QoL of survivors of RB, as perceived by parents and the self-report by patients, through a pediatric QoL (PEDs-QoL) questionnaire. METHODS: The study cohort included 86 RB survivors, 86 age-matched controls, and their primary carers. PedsQL 4.0 generic core scale and structured interview were administered. QoL in physical, social, emotional, and school health was evaluated and correlated with clinical and sociodemographic parameters. RESULTS: The mean age of the RB survivors was 5.7 years with an M:F ratio of 1.1:1. Disease was bilateral in 79% of cases. About 45% (39/86) underwent enucleation, while others received combination therapy (16; 18%), chemotherapy (30; 34%), and radiation (1; 1%). As reported by parents, the QoL of physical health domain of RB survivors was 70.2 SD ± 27.8 and 96.15 ± 13 SD, emotional health was 72.1 ± 27.4 SD and 94.4 ± 12.5 SD, social health was 80.4 ± 24.9 SD and 98.6 ± 6.2 SD; and school health was 71.9 ± 2 6.5 SD and 96.1 ± 12.2 SD. As per the self-report perception, the QoL of physical health was 68.2 ± 27.8 SD and 96.2 ± 13 SD, emotional health was 66.2 ± 28.4 SD and 95.3 ± 12.5 SD, social health was 69.5 ± 24.9 SD and 98.7 ± 6.2 SD, and school health was 63.5 ± 26.5 SD and 95.1 ± 12.2 SD. There was a significant relationship between enucleation and QoL domains, where χ2 = 67.75, degrees of freedom (df) = 36, and P < 0.01. There was a significant association between vision in the better eye (6/18 or better = 8, 6/18-6/60 = 8, 3/60 or worse = 42) and QoL scores (χ2 = 95.36, df = 62, P < 0.01). There was a substantial association between socioeconomic status and QoL domains, where χ2= 88.5, df = 56, P < 0.01. CONCLUSION: The results of the study showed that the QoL of parents of RB survivors and self-proxy reports were negatively affected in many ways, including physical, social, emotional, and school-related dimensions. Despite the small differences, self-proxy reports indicated a lower QoL than the parents' group. The study findings indicate that there are notable correlations between enucleation and visual acuity less than 6/18, as well as socioeconomic status, with various aspects of QoL domains among individuals who have survived RB.

Hematological Second Primary Malignancy in Pediatric Retinoblastoma: A Case Report and Systematic Review.

PURPOSE: The impact of heredity and treatment modalities on the development of hematologic second primary malignancies (SPMs) is unclear. This study primarily reviewed the literature on patients with hematologic SPMs after retinoblastoma. METHODS: The PubMed and Web of Science databases were searched to identify all cases of hematologic SPMs after retinoblastoma through December 2023 (International prospective register of systematic reviews CRD42023488273). RESULTS: Sixty-one patients from 35 independent publications and our case were included. Within the cohort, 15 patients (51.7%) were male, and 14 patients (48.3%) were female. Of the 43 cases with known heritability status, 27 (62.8%) were classified as heritable and 16 (37.2%) as nonheritable. The median age at diagnosis was 18 months (IQR: 7.00-36.00). The geographic distribution of patients was diverse, with North America accounting for 35.0% (21/60) of cases. The following treatment strategies were used: 11.9% (5/42) of patients received neither chemotherapy nor radiotherapy, 33.3% (14/42) received chemotherapy alone, 11.9% (5/42) received radiotherapy alone, and 42.9% (18/42) received a combination of chemotherapy and radiotherapy. The median delay between retinoblastoma diagnosis and SPM diagnosis was 40 months (IQR: 22.00-85.00). Among the 61 cases, acute myeloid leukemia accounted for 44.3% (27/61), followed by acute lymphoblastic leukemia in 21.3% (13/61), Hodgkin's lymphoma in 11.5% (7/61), non-Hodgkin's lymphoma in 9.8% (6/61), chronic myeloid leukemia in 3.3% (2/61), and acute natural killer cell leukemia in 1.6% (1/61). CONCLUSIONS: Vigilant systemic surveillance for hematologic SPMs in retinoblastoma survivors, especially those treated with systemic chemotherapy and those with hereditary conditions, is warranted to improve management strategies and patient outcomes.

Injectable Dendrimer Hydrogel Delivers Melphalan in Both Conjugated and Free Forms for Retinoblastoma.

We report the successful synthesis of an injectable dendrimer hydrogel (DH) carrying melphalan, a clinical drug for retinoblastoma treatment, in both conjugated and free forms. Polyamidoamine (PAMAM) dendrimer generation 5 (G5) is surface-modified with an acid-sensitive acetal-dibenzocyclooctyne linker and then undergoes azide-alkyne cycloaddition with melphalan-PEG-N3 conjugate to form G5-acetal-melphalan. During the DH gelation between G5-acetal-melphalan and PEG-diacrylate, free melphalan is added, resulting in a hydrogel (G5-acetal-melphalan-DH/melphalan) that carries the drug in both conjugated and free forms. Melphalan is slowly released from G5-acetal-melphalan-DH/melphalan, with the conjugated melphalan released more quickly at pH 5.3 due to acid-triggered acetal bond cleavage. The formulation's in vitro safety and efficacy were established on human corneal epithelia (HCE-2) and retinoblastoma cells (Y79). In an in vivo Y79 tumor xenograft model of retinoblastoma, intratumorally injected G5-melphalan-DH formulation prolonged tumor suppression. This injectable, multimodal, pH-responsive formulation shows promise for intravitreal injection to treat retinoblastoma.

Outcome of Retinoblastoma After Implementation of National Retinoblastoma Treatment Guidelines in South Africa.

PURPOSE: Retinoblastoma, a curable childhood cancer, has been identified as a tracer cancer in the WHO Global Initiative for Childhood Cancer. To document the outcomes of children with retinoblastoma in South Africa, treated as per the first prospective standard national treatment guidelines for childhood cancer in South Africa. PATIENTS AND METHODS: All children diagnosed with retinoblastoma between 2012 and 2016 in five South African pediatric oncology units were treated with a standard treatment on the basis of the International Society of Pediatric Oncology-Pediatric Oncology in Developing Countries guidelines for high-income settings. Treatment included focal therapy with/without chemotherapy, or enucleation with/without chemotherapy, and orbital radiotherapy, depending on enucleated eye histology. The end point was survival at 24 months, using Kaplan-Meier curves with log-rank (Mantel-Cox) and chi-square (χ2) tests with respective P values reported. RESULTS: A total of 178 children were included in the study; 68% presented with unilateral disease. The median age was 27 months (range 0-118 months) with a male:female ratio of 1:0.75. The overall survival was 79% at 24 months with significant association with stage at diagnosis (P < .001) and older age over 2 years as opposed to younger than 2 years (P < .001). Causes of death were disease progression/relapses in 90% (34 of 38) and unknown in 2% (1 of 38), whereas treatment abandonment was 1.7% (3 of 178). CONCLUSION: Efficacy with national treatment guidelines was confirmed, and feasibility of implementing standard national childhood cancer treatment guidelines was documented, involving multidisciplinary teams in South Africa. Outcome was significantly associated with stage at diagnosis and age.

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.

Clinical characterization and long-term postoperative outcomes of retinoblastoma patients receiving enucleation and primary orbital implantation in early infancy: an observational study.

OBJECTIVES: To retrospectively investigate clinical characterization and the long-term postoperative outcomes of retinoblastoma (RB) patients receiving enucleation with primary orbital implantation in early infancy (0-6 months old). METHODS: The clinical and follow-up data of 42 RB patients receiving enucleation with primary orbital implantation in early infancy at Beijing Tongren Hospital from December 2009 to January 2020 were analysed. The average follow-up time was 83 months. The patient group included 24 males and 18 females, 30 unilateral and 12 bilateral cases. A total of 44 eyes with 10 in stage D and 34 in stage E underwent 40 unilateral and 2 bilateral surgeries. 17 RB eyes received hydrogel and 27 RB eyes received hydroxyapatite implants. This study was performed by following the guideline of STROBE. RESULTS: Enucleation combined with primary orbital implantation promoted survival and was safe with few and minor complications such as increased secretion, upper eyelid ptosis, and sunken eye sockets which were not affected by stages, lateralities, or implant materials. 55-80% RB patients exhibited satisfactory appearance and obvious or moderate motility of orbital implants according to the evaluation by doctors and family members. Family members were likely more optimistic about the appearance and more pessimistic about motility of the orbital implantation than doctors did.The quality of life was high as indicated by PedsQL3.0 or PedsQL4.0 scores ( ≧ 90 for > 75% patients). It was not affected by the stages, laterality, and implant materials, nor affected by the appearance and motility of the implants. CONCLUSIONS: The outcomes of the combination of enucleation and primary orbital implantation for pertinent RB patients in early infancy are generally satisfactory with few and minor complications, high safety, appearance, and overall quality of life. Enucleation combined with primary orbital implantation in early infancy benefits pertinent RB patients in appearance, survival, and quality of life.

EIF4A3-induced hsa_circ_0078136 inhibits the tumorigenesis of retinoblastoma via IL-17 signaling pathway.

PURPOSE: Retinoblastoma (RB) is one of the most common intraocular cancers, with the highest prevalence among infants and young children under the age five. Numerous findings across the literature illustrate the involvement and significance of circular RNAs (circRNAs) in human malignancies, including RB. The current investigation attempted to decipher the exact roles and underlying mechanisms of a novel circRNA, hsa_circ_0078136, in RB progression. METHODS: The hsa_circ_0078136 expression was evaluated in RB tumors and cell lines via qRT-PCR. The significance of hsa_circ_0078136 in RB was examined by performing CCK8 assay, transwell assays, western blotting of apoptotic and IL-17 signaling ligand molecules, and a subcutaneous xenograft tumor model. In addition, the interaction of circRNA and eukaryotic translation initiation factor 4A3 (EIF4A3) was determined with bioinformatics, western blot, and RIP assay. RESULTS: The hsa_circ_0078136 expression was reduced in RB tumor samples and cells. Additionally, its overexpression restricted the oncogenic properties of RB cells in vitro. Moreover, hsa_circ_0078136 overexpression lowered the protein levels of cytokine ligand molecules of IL-17 signaling pathway in RB cell lines. In vivo, hsa_circ_0078136 overexpression in subcutaneous tumor xenografts reduced tumor growth. We also observed that EIF4A3 binds to the downstream flanking sequence of hsa_circ_0078136 in the SHRPH pre-mRNA transcript, and EIF4A3 overexpression reduced hsa_circ_0078136 expression, suggesting that EIF4A3 inhibited hsa_circ_0078136 formation. CONCLUSIONS: Our results demonstrate that hsa_circ_0078136 is regulated by EIF4A3 and functions as a tumor suppressor via the IL-17 signaling pathway in RB.

Clinical, epidemiological, and care profile of hospitalized patients with retinoblastoma in Brazil.

PURPOSE: To describe the epidemiological and clinical profile of hospitalized patients with retinoblastoma in Brazil. METHODS: Using data from the Hospital Cancer Registry of the Instituto Nacional de Câncer, patients with the morphological codes of retinoblastoma who were diagnosed between 2000 to 2018, aged 0-19 years, and followed up in registered hospitals (analytical cases) were selected. The relative and absolute frequencies of demographic, clinical, diagnostic, therapeutic, and outcome variables were described. Hospital performance indicators were calculated and compared between hospitals qualified and not qualified to treat pediatric oncology cases and between hospitals with different case volumes (<20, 20-75, >75 cases). RESULTS: Of the 2,269 identified analytical cases from 86 institutions, 48% were from the Southeast, 54% were male, and 66% were aged <4 years. The proportion of missing data (NA) was too high for several variables. Approximately 84% of the patients were from the public health system, 40% had a positive family history, and 88% had unilateral involvement. The first treatment included surgery in 58.3% of the patients (NA=2), Approximately 36.6% of these patients achieved complete remission, 10.8% achieved partial remission, and 12.7% died (NA=59%). Hospital performance indicators were within the target in >90% of the patients. The median time between the first appointment and diagnosis (6 days, interquartile range [IQR] 1-14) was significantly lower and the median time to death was longer (343 days, IQR, 212-539) in high-volume hospitals (>75 cases) than in medium- and low-volume hospitals. CONCLUSIONS: Despite the high proportion of missing data, we found that the delay in diagnosis is due to prehospital factors. Additionally, there is a need for educational programs for healthcare professionals and families that emphasize early identification and referral to specialized centers. Future studies should focus on the impact of Hospital Cancer Registry data completeness on outcomes, causes of delay in diagnosis, regional inequalities, and barriers to accessing specialized services.

Polydopamine-Based Targeted Nanosystem for Chemo/Photothermal Therapy of Retinoblastoma in a Mouse Orthotopic Model.

Background: At present, the few photothermal/chemotherapy studies about retinoblastoma that have been reported are mainly restricted to ectopic models involving subcutaneous implantation. However, eyeball is unique physiological structure, the blood-retina barrier (BRB) hinders the absorption of drug molecules through the systemic route. Moreover, the abundant blood circulation in the fundus accelerates drug metabolism. To uphold the required drug concentration, patients must undergo frequent chemotherapy sessions. Purpose: To address these challenges above, we need to develop a secure and effective drug delivery system (FA-PEG-PDA-DOX) for the fundus. Methods: We offered superior therapeutic efficacy with minimal or no side effects and successfully established orthotopic mouse models. We evaluated cellular uptake performance and targeting efficiency of FA-PEG-PDA-DOX nanosystem and assessed its synergistic antitumor effects in vitro and vivo. Biodistribution assessments were performed to determine the retention time and targeting efficiency of the NPs in vivo. Additionally, safety assessments were conducted. Results: Cell endocytosis rates of the FA-PEG-PDA-DOX+Laser group became 5.23 times that of the DOX group and 2.28 times that of FA-PEG-PDA-DOX group without irradiation. The fluorescence signal of FA-PEG-PDA-DOX persisted for more than 120 hours at the tumor site. The number of tumor cells (17.2%) in the proliferative cycle decreased by 61.6% in the photothermal-chemotherapy group, in contrast to that of the saline control group (78.8%). FA-PEG-PDA-DOX nanoparticles(NPs) exhibited favorable biosafety and high biocompatibility. Conclusion: The dual functional targeted nanosystem, with the effects of DOX and mild-temperature elevation by irradiation, resulted in precise chemo/photothermal therapy in nude mice model.

Electroretinographic changes in the inner and outer retinal layers before and after intravenous chemotherapy for retinoblastoma.

PURPOSE: To study the inner and outer retinal functions using a full-field electroretinogram (ERG) before and after intravenous chemotherapy (IVC) in children with retinoblastoma (RB). METHODS: Of the 11 eyes, seven had RB and four were normal. All children were examined under anesthesia using a handheld ERG machine with a standard protocol - light-adapted single-flash ERG (fERG), photopic single-flash 3.0- and 30-Hz flickers, and photopic negative response (PhNR) amplitudes at 72 ms (P72). The amplitudes and peak times were compared before and after IVC. RESULTS: Post-chemotherapy tumor regressed in all seven eyes. Of the seven eyes, the fERG peak time (a-wave) was delayed in two eyes (29%), whereas the b-wave was delayed in six eyes (86%). The fERG amplitude height for a- and b-waves decreased in five eyes (71%) and six eyes (86%), respectively. In addition, photopic flicker 30-Hz b-wave peak time delayed in five eyes (71%), whereas the b-wave amplitude height decreased in six eyes (86%). Simultaneously, the P72 amplitude height decreased in six eyes (86%), whereas the P-ratio increased in all seven eyes (100%). In comparison, the ERG responses improved in three of the four contralateral normal eyes. Overall, the cone function improved in two eyes (29%), whereas cone bipolar cell and retinal ganglion cell (RGC) function improved in one eye (14%) each. CONCLUSION: Comparison of light-adapted ERG changes before and after IVC showed reduced amplitudes and delayed peak times for both a and b waveforms, as well as reduced PhNR amplitude attributable to bipolar and RGC injury.

Comprehensive identification of pathogenic variants in retinoblastoma by long- and short-read sequencing.

Retinoblastoma (RB) is the most common intraocular malignancy in childhood. The causal variants in RB are mostly characterized by previously used short-read sequencing (SRS) analysis, which has technical limitations in identifying structural variants (SVs) and phasing information. Long-read sequencing (LRS) technology has advantages over SRS in detecting SVs, phased genetic variants, and methylation. In this study, we comprehensively characterized the genetic landscape of RB using combinatorial LRS and SRS of 16 RB tumors and 16 matched blood samples. We detected a total of 232 somatic SVs, with an average of 14.5 SVs per sample across the whole genome in our cohort. We identified 20 distinct pathogenic variants disrupting RB1 gene, including three novel small variants and five somatic SVs. We found more somatic SVs were detected from LRS than SRS (140 vs. 122) in RB samples with WGS data, particularly the insertions (18 vs. 1). Furthermore, our analysis shows that, with the exception of one sample who lacked the methylation data, all samples presented biallelic inactivation of RB1 in various forms, including two cases with the biallelic hypermethylated promoter and four cases with compound heterozygous mutations which were missing in SRS analysis. By inferring relative timing of somatic events, we reveal the genetic progression that RB1 disruption early and followed by copy number changes, including amplifications of Chr2p and deletions of Chr16q, during RB tumorigenesis. Altogether, we characterize the comprehensive genetic landscape of RB, providing novel insights into the genetic alterations and mechanisms contributing to RB initiation and development. Our work also establishes a framework to analyze genomic landscape of cancers based on LRS data.

[Liposome co-delivery of quercetin and doxorubicin in inhibiting retinoblastoma by regulating epithelial-mesenchymal transition process].

Regulating the process of epithelial-mesenchymal transition(EMT) is an essential strategy to inhibit tumor growth and metastasis. This study is based on the EMT process of retinoblastoma and constructs quercetin(QUE) and doxorubicin(DOX) co-loaded liposome(QD Lipo) to investigate the therapeutic effect and mechanisms of combined QUE and DOX treatment on retinoblastoma. Single-factor experiments were conducted to optimize the prescription process of QD Lipo. Eventually, spherical particles with a diameter of(108.87±1.93) nm, a PDI of 0.13±0.02, and a Zeta potential of(-34.83±1.92) mV were obtained. The encapsulation rates of QUE and DOX were 96.20%±4.40% and 91.17%±4.41%, respectively. Y79 human retinoblastoma cells were used as an in vitro cellular model, and confocal microscopy demonstrated that QD Lipo could enhance Y79 uptake efficiency. The CCK-8 assay confirmed that the optimal combination therapy effect of QUE and DOX occurred at a mass ratio of 1∶1 to 1∶2. Flow cytometry showed that QD Lipo enhanced the induction of apoptosis in Y79 cells. Western blot analysis revealed that QD Lipo significantly reduced the expression of EMT pathway-related proteins vimentin and α-SMA. Fluorescence assays detected a significant decrease in ROS levels in Y79 cells after treatment with QD. These results indicated that liposomal co-delivery of QUE and DOX can enhance drug delivery efficiency to retinoblastoma cells, inhibit the EMT process in retinoblastoma by downregulating ROS levels, and enhance the cytotoxicity of DOX against retinoblastoma.

A MYCN-driven de-differentiation profile identifies a subgroup of aggressive retinoblastoma.

Retinoblastoma are childhood eye tumors arising from retinal precursor cells. Two distinct retinoblastoma subtypes with different clinical behavior have been described based on gene expression and methylation profiling. Using consensus clustering of DNA methylation analysis from 61 retinoblastomas, we identify a MYCN-driven cluster of subtype 2 retinoblastomas characterized by DNA hypomethylation and high expression of genes involved in protein synthesis. Subtype 2 retinoblastomas outside the MYCN-driven cluster are characterized by high expression of genes from mesodermal development, including NKX2-5. Knockdown of MYCN expression in retinoblastoma cell models causes growth arrest and reactivates a subtype 1-specific photoreceptor signature. These molecular changes suggest that removing the driving force of MYCN oncogenic activity rescues molecular circuitry driving subtype 1 biology. The MYCN-RB gene signature generated from the cell models better identifies MYCN-driven retinoblastoma than MYCN amplification and can identify cases that may benefit from MYCN-targeted therapy. MYCN drives tumor progression in a molecularly defined retinoblastoma subgroup, and inhibiting MYCN activity could restore a more differentiated and less aggressive tumor biology.

Study on the role of MYCN in retinoblastoma by inhibiting p53 and activating wnt/ßcatenin/Fra-1 signaling pathway by reducing DKK3.

Retinoblastoma (RB) is a pediatric malignancy, typically diagnosed at birth or during early childhood. The pathogenesis of RB is marked by the amplification of the Basic Helix-Loop-Helix (BHLH) Transcription Factor MYCN, which serves as a transcriptional regulator capable of binding to Dickkopf 3 (DKK3). However, the precise role of DKK3 in the malignant progression of RB cells caused by MYCN remains elusive. In the present study, the expression of MYCN was either overexpressed or interfered in RB cells. Subsequently, the expression level of DKK3 was assessed through quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was evaluated using the Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine staining, while cell cycle progression and apoptosis were analyzed by flow cytometry and western blot analysis, respectively. Additionally, the expression of proteins involved in the Wnt/ß-catenin/Fra-1/p53 signaling pathway was evaluated via western blot analysis. To gain further insights, Wnt agonists and the P53 inhibitor PFT-α were introduced into exploration. The current investigation revealed a negative correlation between the expression levels of MYCN and DKK3 in RB cells. Additionally, DKK3 overexpression inhibited cell proliferation, promoted cell apoptosis, and arrested cell cycle in RB cells with high expression of MYCN. Moreover, enhanced DKK3 expression inhibited proliferation, promoted cell cycle arrest and apoptosis of RB cells by modulating the wnt/ßcatenin/Fra-1/p53 signaling pathway. Furthermore, in vivo experiments revealed that overexpression of DKK3 inhibits the growth of RB tumors. Collectively, our findings elucidate that MYCN stimulates the Wnt/ß-catenin/Fra-1 pathway by suppressing DKK3 expression, ultimately suppressing p53 activity and contributing to malignant progression of RB.