Loss of RB1 induces non-proliferative retinoma: increasing genomic instability correlates with progression to retinoblastoma

Targeting ALDOA to modulate tumorigenesis and energy metabolism in retinoblastoma

This study aims to elucidate the pivotal role of aldolase A (ALDOA) in retinoblastoma (RB) and evaluate the potential of the ALDOA inhibitor itaconate in impeding RB progression. Utilizing single-cell RNA sequencing, ALDOA consistently exhibits overexpression across diverse cell types, particularly in cone precursor cells, retinoma-like cells, and retinoblastoma-like cells. This heightened expression is validated in RB tissues and cell lines. ALDOA knockdown significantly diminishes RB cell viability, impedes colony formation, and induces notable metabolic alterations. RNA-seq analysis identifies SUSD2, ARHGAP27, and CLK2 as downstream genes associated with ALDOA. The application of itaconate demonstrates efficacy in inhibiting RB cell proliferation, validated through in vitro and in vivo models. This study emphasizes ALDOA as a promising target for innovative RB therapies, with potential implications for altering tumor energy metabolism.

Aurora Kinase A Is Overexpressed in Human Retinoblastoma and Correlates with Histopathologic High-Risk Factors: Implications for Targeted Therapy

Retinoblastoma (RB) is an intraocular malignancy initiated by loss of RB1 function and/or dysregulation of MYCN oncogene. RB is primarily treated with chemotherapy; however, systemic toxicity and long-term adverse effects remain a significant challenge necessitating the identification of specific molecular targets. Aurora kinase A (AURKA), a critical cell cycle regulator, contributes to cancer pathogenesis, especially in RB1-deficient and MYCN-dysregulated tumors. The current immunohistochemistry study in patient specimens (n = 67) indicated that AURKA is overexpressed in RB, and this elevated expression correlates with one or more histopathologic high-risk factors, such as tumor involvement of the optic nerve, choroid, sclera, and/or anterior segment. More specifically, AURKA is ubiquitously expressed in most advanced-stage RB tumors that show a suboptimal response to chemotherapy. shRNA-mediated depletion/pharmacologic inhibition studies in cell lines, patient-derived cells, in vivo xenografts, and enucleated patient specimens confirmed that RB cells are highly sensitive to a lack of functional AURKA. In addition, AURKA and N-myc proto-oncogene protein (MYCN) associate with each other to regulate their levels in RB cells. Overall, these results demonstrate a previously unknown up-regulation of AURKA in RB, facilitated by its crosstalk with MYCN. The elevated levels of this kinase may indicate unfavorable prognosis in tumors refractory to chemotherapy. This study provides a rationale and confirms that therapeutic targeting of elevated AURKA in RB could be a potential treatment approach.

Retinoblastoma caused by an RB1 variant with unusually low penetrance in a Danish family

Retinoblastoma is the most common eye cancer in children. It is caused by pathogenic alterations of both alleles of the tumor suppressor gene RB1. In heritable retinoblastoma, a constitutional RB1 variant predisposes the cells to tumor formation, and loss of the other allele is a prerequisite for the development of retinoblastoma. Heritable retinoblastoma is inherited in an autosomal dominant manner; however, the majority of cases are the result of a de novo pathogenic RB1 variant. Penetrance is usually high (>90%), but with marked inter-familial variability. In some families, penetrance is incomplete and family members who develop tumors tend to remain unilaterally affected. Moreover, some families with low penetrance also show a parent-of-origin effect. We describe a patient with unilateral retinoblastoma caused by a previously unreported likely pathogenic RB1 variant (c.1199T>C) that disrupts a highly conserved amino acid residue within the A-box functional domain. Segregation analysis showed that the variant had unusually low penetrance as nine non-affected family members carried the same variant. We emphasize the use of genetic analysis on tumor DNA for classifying the RB1 variant, and underline the challenges in clinical management and counseling of families carrying the specific RB1 variant.

Histone Deacetylases in Retinoblastoma

Retinoblastoma, a pediatric ocular malignancy, presents significant challenges in comprehending its molecular underpinnings and targeted therapeutic approaches. The dysregulated activity of histone deacetylases (HDACs) has been associated with retinoblastoma pathogenesis, influencing critical cellular processes like cell cycle regulation or retinal ganglion cell apoptosis. Through their deacetylase activity, HDACs exert control over key tumor suppressors and oncogenes, influencing the delicate equilibrium between proliferation and cell death. Furthermore, the interplay between HDACs and the retinoblastoma protein pathway, a pivotal aspect of retinoblastoma etiology, reveals a complex network of interactions influencing the tumor microenvironment. The examination of HDAC inhibitors, encompassing both established and novel compounds, offers insights into potential approaches to restore acetylation balance and impede retinoblastoma progression. Moreover, the identification of specific HDAC isoforms exhibiting varying expression in retinoblastoma provides avenues for personalized therapeutic strategies, allowing for interventions tailored to individual patient profiles. This review focuses on the intricate interrelationship between HDACs and retinoblastoma, shedding light on epigenetic mechanisms that control tumor development and progression. The exploration of HDAC-targeted therapies underscores the potential for innovative treatment modalities in the pursuit of more efficacious and personalized management strategies for this disease.

Disruption of common ocular developmental pathways in patient-derived optic vesicle models of microphthalmia

Genetic perturbations influencing early eye development can result in microphthalmia, anophthalmia, and coloboma (MAC). Over 100 genes are associated with MAC, but little is known about common disease mechanisms. In this study, we generated induced pluripotent stem cell (iPSC)-derived optic vesicles (OVs) from two unrelated microphthalmia patients and healthy controls. At day 20, 35, and 50, microphthalmia patient OV diameters were significantly smaller, recapitulating the "small eye" phenotype. RNA sequencing (RNA-seq) analysis revealed upregulation of apoptosis-initiating and extracellular matrix (ECM) genes at day 20 and 35. Western blot and immunohistochemistry revealed increased expression of lumican, nidogen, and collagen type IV, suggesting ECM overproduction. Increased apoptosis was observed in microphthalmia OVs with reduced phospho-histone 3 (pH3+) cells confirming decreased cell proliferation at day 35. Pharmacological inhibition of caspase-8 activity with Z-IETD-FMK decreased apoptosis in one patient model, highlighting a potential therapeutic approach. These data reveal shared pathophysiological mechanisms contributing to a microphthalmia phenotype.

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.

Deciphering metabolic heterogeneity in retinoblastoma unravels the role of monocarboxylate transporter 1 in tumor progression

BACKGROUND

Tumors exhibit metabolic heterogeneity, influencing cancer progression. However, understanding metabolic diversity in retinoblastoma (RB), the primary intraocular malignancy in children, remains limited.

METHODS

The metabolic landscape of RB was constructed based on single-cell transcriptomic sequencing from 11 RB and 5 retina samples. Various analyses were conducted, including assessing overall metabolic activity, metabolic heterogeneity, and the correlation between hypoxia and metabolic pathways. Additionally, the expression pattern of the monocarboxylate transporter (MCT) family in different cell clusters was examined. Validation assays of MCT1 expression and function in RB cell lines were performed. The therapeutic potential of targeting MCT1 was evaluated using an orthotopic xenograft model. A cohort of 47 RB patients was analyzed to evaluate the relationship between MCT1 expression and tumor invasion.

RESULTS

Distinct metabolic patterns in RB cells, notably increased glycolysis, were identified. This metabolic heterogeneity correlated closely with hypoxia. MCT1 emerged as the primary monocarboxylate transporter in RB cells. Disrupting MCT1 altered cell viability and energy metabolism. In vivo studies using the MCT1 inhibitor AZD3965 effectively suppressed RB tumor growth. Additionally, a correlation between MCT1 expression and optic nerve invasion in RB samples suggested prognostic implications.

CONCLUSIONS

This study enhances our understanding of RB metabolic characteristics at the single-cell level, highlighting the significance of MCT1 in RB pathogenesis. Targeting MCT1 holds promise as a therapeutic strategy for combating RB, with potential prognostic implications.

Pluripotent stem cell-derived models of retinal disease: Elucidating pathogenesis, evaluating novel treatments, and estimating toxicity

Blindness poses a growing global challenge, with approximately 26% of cases attributed to degenerative retinal diseases. While gene therapy, optogenetic tools, photosensitive switches, and retinal prostheses offer hope for vision restoration, these high-cost therapies will benefit few patients. Understanding retinal diseases is therefore key to advance effective treatments, requiring in vitro models replicating pathology and allowing quantitative assessments for drug discovery. Pluripotent stem cells (PSCs) provide a unique solution given their limitless supply and ability to differentiate into light-responsive retinal tissues encompassing all cell types. This review focuses on the history and current state of photoreceptor and retinal pigment epithelium (RPE) cell generation from PSCs. We explore the applications of this technology in disease modelling, experimental therapy testing, biomarker identification, and toxicity studies. We consider challenges in scalability, standardisation, and reproducibility, and stress the importance of incorporating vasculature and immune cells into retinal organoids. We advocate for high-throughput automation in data acquisition and analyses and underscore the value of advanced micro-physiological systems that fully capture the interactions between the neural retina, RPE, and choriocapillaris.

Therapeutic Strategies for RB1-Deficient Cancers: Intersecting Gene Regulation and Targeted Therapy

The retinoblastoma (RB) transcriptional corepressor 1 (RB1) is a critical tumor suppressor gene, governing diverse cellular processes implicated in cancer biology. Dysregulation or deletion in RB1 contributes to the development and progression of various cancers, making it a prime target for therapeutic intervention. RB1's canonical function in cell cycle control and DNA repair mechanisms underscores its significance in restraining aberrant cell growth and maintaining genomic stability. Understanding the complex interplay between RB1 and cellular pathways is beneficial to fully elucidate its tumor-suppressive role across different cancer types and for therapeutic development. As a result, investigating vulnerabilities arising from RB1 deletion-associated mechanisms offers promising avenues for targeted therapy. Recently, several findings highlighted multiple methods as a promising strategy for combating tumor growth driven by RB1 loss, offering potential clinical benefits in various cancer types. This review summarizes the multifaceted role of RB1 in cancer biology and its implications for targeted therapy.

Smart Nanocarriers for the Treatment of Retinal Diseases

Retinal diseases, such as age-related macular degeneration, diabetic retinopathy, and retinoblastoma, stand as the leading causes of irreversible vision impairment and blindness worldwide. Effectively administering drugs for retinal diseases poses a formidable challenge due to the presence of complex ocular barriers and elimination mechanisms. Over time, various approaches have been developed to fabricate drug delivery systems for improving retinal therapy including virus vectors, lipid nanoparticles, and polymers. However, conventional nanocarriers encounter issues related to the controllability, efficiency, and safety in the retina. Therefore, the development of smart nanocarriers for effective or more invasive long-term treatment remains a desirable goal. Recently, approaches have surfaced for the intelligent design of nanocarriers, leveraging specific responses to external or internal triggers and enabling multiple functions for retinal therapy such as topical administration, prolonged drug release, and site-specific drug delivery. This Review provides an overview of prevalent retinal pathologies and related pharmacotherapies to enhance the understanding of retinal diseases. It also surveys recent developments and strategies employed in the intelligent design of nanocarriers for retinal disease. Finally, the challenges of smart nanocarriers in potential clinical retinal therapeutic applications are discussed to inspire the next generation of smart nanocarriers.

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.

Heterogeneous Expression Patterns of the Minichromosome Maintenance Complex Members in Retinoblastoma Unveil Its Clinical Significance

Purpose

To explore the expression patterns and clinical significance of minichromosome maintenance (MCM) complex members in retinoblastoma (RB).

Methods

Single-cell RNA sequencing datasets from five normal retina, six intraocular, and five extraocular RB samples were integrated to characterize the expression patterns of MCM complex members at the single-cell level. Western blot and quantitative PCR were used to detect the expression of MCM complex members in RB cell lines. Immunohistochemistry was conducted to validate the expression of MCM complex members in RB patient samples and a RB mouse model.

Results

The expression of MCM2-7 is increased in RB tissue, with MCM2/3/7 showing particularly higher levels in extraocular RB. MCM3/7 are abundantly detected in cell types associated with oncogenesis. Both mRNA and protein levels of MCM3/4/6/7 are increased in RB cell lines. Immunohistochemistry further confirmed the elevated expression of MCM3 in extraocular RB, with MCM6 being the most abundantly expressed MCM in RB.

Conclusions

The distinct MCM expression patterns across various RB cell types suggest diverse functional roles, offering valuable insights for targeted therapeutic strategies. The upregulation of MCM3, MCM4, MCM6, and MCM7 in RB, with a specific emphasis on MCM6 as a notable marker, highlights their potential significance.

Cancer Associated PRDM9: Implications for Linking Genomic Instability and Meiotic Recombination

The PR domain-containing 9 or PRDM9 is a gene recognized for its fundamental role in meiosis, a process essential for forming reproductive cells. Recent findings have implicated alterations in the PRDM9, particularly its zinc finger motifs, in the onset and progression of cancer. This association is manifested through genomic instability and the misregulation of genes critical to cell growth, proliferation, and differentiation. In our comprehensive study, we harnessed advanced bioinformatic mining tools to delve deep into the intricate relationship between PRDM9F and cancer. We analyzed 136,752 breakpoints and found an undeniable association between specific PRDM9 motifs and the occurrence of double-strand breaks, a phenomenon evidenced in every cancer profile examined. Utilizing R statistical querying and the Regioner package, 55 unique sequence variations of PRDM9 were statistically correlated with cancer, from a pool of 1024 variations. A robust analysis using the Enrichr tool revealed prominent associations with various cancer types. Moreover, connections were noted with specific phenotypic conditions and molecular functions, underlining the pervasive influence of PRDM9 variations in the biological spectrum. The Reactome tool identified 25 significant pathways associated with cancer, offering insights into the mechanistic underpinnings linking PRDM9 to cancer progression. This detailed analysis not only confirms the pivotal role of PRDM9 in cancer development, but also unveils a complex network of biological processes influenced by its variations. The insights gained lay a solid foundation for future research aimed at deciphering the mechanistic pathways of PRDM9, offering prospects for targeted interventions and innovative therapeutic approaches in cancer management.

Validation of an on-chip p16ink4a/Ki-67 dual immunostaining cervical cytology system using microfluidic device technology

More specific screening systems for cervical cancer may become necessary as the human papillomavirus (HPV) vaccine becomes more widespread. Although p16/Ki-67 dual-staining cytology has several advantages, it requires advanced diagnostic skills. Here, we developed an automated on-chip immunostaining method using a microfluidic device. An electroactive microwell array (EMA) microfluidic device with patterned thin-film electrodes at the bottom of each microwell was used for single-cell capture by dielectrophoresis. Immunostaining and dual staining for p16/Ki-67 were performed on diagnosed liquid cytology samples using the EMA device. The numbers of p16/Ki-67 dual-stained cells captured by the EMA device were determined and compared among the cervical intraepithelial neoplasia (CIN) lesion samples. Seven normal, fifteen CIN grade 3, and seven CIN grade 2 samples were examined. The percentage of dual-positive cells was 18.6% in the CIN grade 2 samples and 23.6% in the CIN grade 3 samples. The percentages of dual-positive staining increased significantly as the severity of the cervical lesions increased. p16/Ki67 dual immunostaining using the EMA device is as sensitive as the conventional method of confirming the histopathological diagnosis of cervical samples. This system enables a quantified parallel analysis at the individual cell level.

RB1 gene mutations and genetic spectrum in retinoblastoma cases

The aim of the study was to investigate the frequency and types of mutations on the retinoblastoma gene (RB1 gene) in Turkish population. RB1 gene mutation analysis was performed in a total of 219 individuals (122 probands with retinoblastoma, 14 family members with retinoblastoma and 83 clinically healthy family members). All 27 exons and close intronic regions of the RB1 gene were sequenced for small deletions and insertions using both the Sanger sequencing or NGS methods, and the large deletions and duplications were investigated using the MLPA analysis and CNV algorithm. The bilateral/trilateral retinoblastoma rate was 66% in the study population. The general frequency of RB1 gene mutation in the germline of the patients with retinoblastoma was 41.9%. Approximately 51.5% of the patients were diagnosed earlier than 12 months old, and de novo mutation was found in 32.4% of the patients. Germline small genetic rearrangement mutations were detected in 78.9% of patients and LGRs were detected in 21.1% of patients. An association was detected between the eye color of the RB patients and RB1 mutations. 8 of the mutations detected in the RB1 gene were novel in the study.

Genetics in ophthalmology: molecular blueprints of retinoblastoma

This review presents current knowledge on the molecular biology of retinoblastoma (RB). Retinoblastoma is an intraocular tumor with hereditary and sporadic forms. 8,000 new cases of this ocular malignancy of the developing retina are diagnosed each year worldwide. The major gene responsible for retinoblastoma is RB1, and it harbors a large spectrum of pathogenic variants. Tumorigenesis begins with mutations that cause RB1 biallelic inactivation preventing the production of functional pRB proteins. Depending on the type of mutation the penetrance of RB is different. However, in small percent of tumors additional genes may be required, such as MYCN, BCOR and CREBBP. Additionally, epigenetic changes contribute to the progression of retinoblastoma as well. Besides its role in the cell cycle, pRB plays many additional roles, it regulates the nucleosome structure, participates in apoptosis, DNA replication, cellular senescence, differentiation, DNA repair and angiogenesis. Notably, pRB has an important role as a modulator of chromatin remodeling. In recent years high-throughput techniques are becoming essential for credible biomarker identification and patient management improvement. In spite of remarkable advances in retinoblastoma therapy, primarily in high-income countries, our understanding of retinoblastoma and its specific genetics still needs further clarification in order to predict the course of this disease and improve therapy. One such approach is the tumor free DNA that can be obtained from the anterior segment of the eye and be useful in diagnostics and prognostics.

Genomic instability and eye diseases

Background

Genetic information is stored in the bases of double-stranded DNA. However, the integrity of DNA molecules is constantly threatened by various mutagenic agents, including pollutants, ultraviolet light (UV), and medications. To counteract these environmental damages, cells have established multiple mechanisms, such as producing molecules to identify and eliminate damaged DNA, as well as reconstruct the original DNA structures. Failure or insufficiency of these mechanisms can cause genetic instability. However, the role of genome stability in eye diseases is still under-researched, despite extensive study in cancer biology.

Main text

As the eye is directly exposed to the external environment, the genetic materials of ocular cells are constantly under threat. Some of the proteins essential for DNA damage repair, such as pRb, p53, and RAD21, are also key during the ocular disease development. In this review, we discuss five ocular diseases that are associated with genomic instability. Retinoblastoma and pterygium are linked to abnormal cell cycles. Fuchs' corneal endothelial dystrophy and age-related macular degeneration are related to the accumulation of DNA damage caused by oxidative damage and UV. The mutation of the subunit of the cohesin complex during eye development is linked to sclerocornea.

Conclusions

Failure of DNA damage detection or repair leads to increased genomic instability. Deciphering the role of genomic instability in ocular diseases can lead to the development of new treatments and strategies, such as protecting vulnerable cells from risk factors or intensifying damage to unwanted cells.

Retinoblastoma: A review of the molecular basis of tumor development and its clinical correlation in shaping future targeted treatment strategies

Retinoblastoma is a retinal cancer that affects children and is the most prevalent intraocular tumor worldwide. Despite tremendous breakthroughs in our understanding of the fundamental mechanisms that regulate progression of retinoblastoma, the development of targeted therapeutics for retinoblastoma has lagged. Our review highlights the current developments in the genetic, epigenetic, transcriptomic, and proteomic landscapes of retinoblastoma. We also discuss their clinical relevance and potential implications for future therapeutic development, with the aim to create a frontline multimodal therapy for retinoblastoma.

EZH2 Expression in Retinoblastoma: A Potential Therapeutic Target

INTRODUCTION

The enhancer of zeste homolog 2 (EZH2) is a member of the polycomb repressive complex 2 (PRC2) and is important in cell-cycle regulation. Increased expression of EZH2 has been reported in retinoblastoma (RB). The aim of the study was to determine EZH2 expression, compare this with clinicopathological parameters in RB, and assess its relationship with tumor cell proliferation.

METHODS

Ninety-nine retrospective cases of enucleated RB were included in the present study. Expression of EZH2 and the marker of cell proliferation, Ki67, were investigated by immunohistochemistry.

RESULTS

Among the 99 cases of RB in this study, EZH2 was found highly expressed (positive expression rate ≥70%) in 92 cases. EZH2 was expressed in tumor cells but absent in normal retinal tissues. The expression of EZH2 was positively linked to Ki67 expression (r = 0.65, p < 0.001).

CONCLUSION

Elevated EZH2 expression was found in most RB cases, indicating that EZH2 could be a potential therapeutic target for RB.

Prognostic and Clinicopathological Significance of the Loss of Expression of Retinoblastoma Protein (pRb) in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to evaluate the scientific evidence on the implications of retinoblastoma protein (pRb) alterations in oral cancer, in order to determine its prognostic and clinicopathological significance. PubMed, Embase, Web of Science, and Scopus were searched for studies published before February 2022, with no restrictions by publication date or language. The quality of the studies using the Quality in Prognosis Studies tool (QUIPS tool). Meta-analysis was conducted to achieve the proposed objectives, as well as heterogeneity, subgroup, meta-regression, and small study-effects analyses. Twenty studies that met the inclusion criteria (2451 patients) were systematically reviewed and meta-analyzed. Our results were significant for the association between the loss of pRb expression and a better overall survival (HR = 0.79, 95%CI = 0.64-0.98, p = 0.03), whereas no significant results were found for disease-free survival or clinico-pathological parameters (T/N status, clinical stage, histological grade). In conclusion, our evidence-based results demonstrate that loss of pRb function is a factor associated with improved survival in patients with OSCC. Research lines that should be developed in the future are highlighted.

Clinical characteristics, treatment and prognosis of infants with retinoblastoma: a multicenter, 10-year retrospective analysis

BACKGROUND

To summarize the characteristics and treatment, and analyze the prognosis of large number of infants with retinoblastoma (RB) in China through a multicenter, 10-year retrospective analysis.

METHODS

The data of RB infants were collected from multiple centers. The characteristics and survival prognosis were analyzed. The overall survival (OS) rate was estimated by the Kaplan-Meier method. Multivariate Cox survival analysis was to evaluate the independent risk factors affecting the prognosis of RB infants.

RESULTS

A total of 373 RB infants (202 boys and 171 girls) were included, the median age was 6.22 months (10 days to 11.93 months). The median follow-up time of RB infants was 18.4 (1.02-122.81 months). After excluding the lost to follow-up cases, the OS rate was 97.7% (345/353). Kaplan-Meier survival analysis indicated that 9 cases died and the median survival time was not reached. Univariate analysis of prognostic factors revealed eye affected, presenting signs, left eye stage and recurrence to be poor prognostic factors for OS rate in RB infants (all P < 0.05). Multivariate Cox regression analyses for OS showed recurrence (HR = 1.376, 95% CI: 0.878-2.156, P = 0.048) was an independent factor for prognosis of infants with RB. The median survival time of infants underwent chemotherapy + intra-arterial chemotherapy (IAC) + enucleation + vitrectomy was the longest than other treatments (n = 9, 47.64 months, OS = 100%, all P < 0.05). There was a history of RB in 17 infants' lineal relatives. Kaplan-merier survival analysis indicated 1 case died and the median survival time was not reached.

CONCLUSION

Recurrence is an independent factor for prognosis of RB infants, which still needs attention after treatment. Early screening, comprehensive treatments and follow-up of patients may lead to improvements of prognosis of RB infants.

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

Identification of novel genes by targeted exome sequencing in Retinoblastoma

BACKGROUND

Retinoblastoma (RB) is initiated by mutation in both alleles of RB1 gene. However, few cases may occur even in the absence of RB1 mutation suggesting the role of genes other than RB1.

METHODOLOGY

The current study was planned to utilize targeted exome sequencing in Indian RB patients affected with unilateral non-familial RB. 75 unilateral RB patients below 5 years of age were enrolled. Genomic DNA was extracted from blood and tumor tissue. From peripheral blood DNA, all coding and exon/intron regions were amplified using PCR and direct sequencing. Cases which did not harbor pathogenic variants in peripheral blood DNA were further screened for mutations in their tumor tissue DNA using targeted exome sequencing. Three pathogenicity prediction tools (Mutation Taster, SIFT, and PolyPhen-2) were used to determine the pathogenicity of non-synonymous variations. An in-house bioinformatics pipeline was devised for the mutation screening by targeted exome sequencing. Protein modeling studies were also done to predict the effect of the mutations on the protein structure and function.

RESULTS

Using the mentioned approach, we found two novel variants (g.69673_69674insT and g.48373314C>A) in RB1 gene in peripheral blood DNA. We also found novel variants in eight genes (RB1, ACAD11, GPR151, KCNA1, OTOR, SOX30, ARL11, and MYCT1) that may be associated with RB pathogenesis.

CONCLUSION

The present study expands our current knowledge regarding the genomic landscape of RB and also highlights the importance of NGS technologies to detect genes and novel variants that may play an important role in cancer initiation, progression, and prognosis.

A t(11;14)(q13;q32)/CCND1::IGH carrying progenitor germinal B-cell with subsequent cytogenetic aberrations contributes to the development of classic Hodgkin lymphoma

Classic Hodgkin lymphoma (cHL) is characterized by the presence of Hodgkin Reed-Sternberg (HRS) cells. Although HRS cells express PAX5, cHL frequently lacks other B-cell markers. There is now evidence that HRS cells are monoclonal and are derived from germinal center B-cells. In terms of genetic aberrations, cHL frequently exhibit activated NF-kB signaling pathway. In this study, we present a case of cHL harboring a t(11;14) (q13;q32)/CCND1::IGH, identified by chromosome and fluorescence in situ hybridization analysis and with CCND1 expression in HRS cells. We also analyzed recurrent cytogenetic aberrations in t(11;14) positive mantle cell lymphoma (MCL) and those found in cHL from the literature to assess genetic overlap, clonal evolution, and to identify potential signaling pathways in cHL with CCND1::IGH. This analysis suggests the development of t(11;14)+ cHL and MCL from a transformed precursor cell with t(11;14) through genetic evolution and consequent deregulated pathways, including the NF-κB and NOTCH1 signaling.

Hallmarks of Cancer Expression in Oral Lichen Planus: A Scoping Review of Systematic Reviews and Meta-Analyses

Oral lichen planus (OLP) is a common chronic inflammatory disease of unknown etiology and likely autoimmune nature that is currently considered an oral potentially malignant disorder, implying that patients suffering from this process are at risk of developing oral cancer in their lifetime. The molecular alterations that develop in OLP and that make the affected oral epithelium predisposed to malignancy are unknown, although, as in other autoimmune diseases (ulcerative colitis, primary biliary cirrhosis, etc.), they may be linked to oncogenesis-promoting effects mediated by the inflammatory infiltrate. So far there is no in-depth knowledge on how these hallmarks of cancer are established in the cells of the oral epithelium affected by OLP. In this scoping review of systematic reviews and meta-analyses the state of evidence based knowledge in this field is presented, to point out gaps of evidence and to indicate future lines of research. MEDLINE, Embase, Cochrane Library and Dare were searched for secondary-level studies published before October 2022. The results identified 20 systematic reviews and meta-analyses critically appraising the hallmarks tumor-promoting inflammation (n = 17, 85%), sustaining proliferative signaling (n = 2, 10%), and evading growth suppressors (n = 1, 5%). No evidence was found for the other hallmarks of cancer in OLP. In conclusion, OLP malignization hypothetically derives from the aggressions of the inflammatory infiltrate and a particular type of epithelial response based on increased epithelial proliferation, evasion of growth-suppressive signals and lack of apoptosis. Future evidence-based research is required to support this hypothesis.

E2F1/CKS2/PTEN signaling axis regulates malignant phenotypes in pediatric retinoblastoma

Retinoblastoma (RB) is the most common pediatric intraocular malignancy and is a serious vision- and life-threatening disease. The biallelic mutation of the retinoblastoma gene RB1 is the initial event in the malignant transformation of RB, but the exact molecular mechanism is still unclear. E2F transcription factors can be activated by RB1 loss of function and lead to uncontrolled cell division. Among E2F family numbers, E2F1 has higher expression abundance than E2F2 and E2F3 in RB clinical samples. By integrating E2F1 ChIP-seq data, RNA-seq profiling from RB samples and RNA-seq profiling upon E2F1 knockdown, together with pathway analysis, literature searching and experimental validation, we identified Cyclin-dependent kinases regulatory subunit 2 (CKS2) as a novel regulator in regulating tumor-associated phenotypes in RB. CKS2 exhibited aberrantly higher expression in RB. Depletion of CKS2 in Y79 retinoblastoma cell line led to reduced cell proliferation, delayed DNA replication and decreased clonogenic growth. Downregulation of CKS2 also slowed tumor xenograft growth in nude mice. Importantly, reversed expression of CKS2 rescued cancer-associated phenotypes. Mechanistically, transcription factor E2F1 enhanced CKS2 expression through binding to its promoter and CKS2 regulated the cancer-associated PI3K-AKT pathway. This study discovered E2F1/CKS2/PTEN signaling axis regulates malignant phenotypes in pediatric retinoblastoma, and CKS2 may serve as a potential therapeutic target for this disease.

RB1 loss triggers dependence on ESRRG in retinoblastoma

Retinoblastoma (Rb) is a deadly childhood eye cancer that is classically initiated by inactivation of the RB1 tumor suppressor. Clinical management continues to rely on nonspecific chemotherapeutic agents that are associated with treatment resistance and toxicity. Here, we analyzed 103 whole exomes, 20 whole transcriptomes, 5 single-cell transcriptomes, and 4 whole genomes from primary Rb tumors to identify previously unknown Rb dependencies. Several recurrent genomic aberrations implicate estrogen-related receptor gamma (ESRRG) in Rb pathogenesis. RB1 directly interacts with and inhibits ESRRG, and RB1 loss uncouples ESRRG from negative regulation. ESRRG regulates genes involved in retinogenesis and oxygen metabolism in Rb cells. ESRRG is preferentially expressed in hypoxic Rb cells in vivo. Depletion or inhibition of ESRRG causes marked Rb cell death, which is exacerbated in hypoxia. These findings reveal a previously unidentified dependency of Rb cells on ESRRG, and they implicate ESRRG as a potential therapeutic vulnerability in Rb.

Second hit impels oncogenesis of retinoblastoma in patient-induced pluripotent stem cell-derived retinal organoids: direct evidence for Knudson's theory

Retinoblastoma (Rb) is a type of malignant tumor due to abnormal retinogenesis with biallelic mutations of the RB1 gene. Its pathogenesis has been proposed as a "two-mutation hypothesis" by Knudson since 1971; however, there remain some debates on disease onset sufficiency of the biallelic RB1 mutations. To obtain straightforward evidence for this hypothesis, we investigated whether two-hit mutations of the RB1 gene drive tumorigenesis in patient-induced pluripotent stem cell (hiPSC)-derived human retinal organoids (hROs) and whether single allelic mutation hiPSC-derived hROs exhibit molecular and cellular defects. We generated hiPSCs with a heterozygous germline mutation (RB1^{m1/ wt} ) from a Rb patient. A second-allele RB1 gene mutation was knocked in to produce compound heterozygous mutations (RB1^m1/m2 ) in the hiPSCs. These two hiPSC lines were independently developed into hROs through a stepwise differentiation. The hiPSC-RB1^m1/m2 derived organoids demonstrated tumorigenesis in dishes, consistent with Rb profiles in spatiotemporal transcriptomes, in which developmentally photoreceptor fate-determining markers, CRX and OTX2, were highly expressed in hiPSC-RB1^m1/m2 derived hROs. Additionally, ARR3⁺ maturing cone precursors were co-labeled with proliferative markers Ki67 or PCNA, in agreement with the consensus that human Rb is originated from maturing cone precursors. Finally, we demonstrated that retinal cells of hROs with monoallelic RB1 mutation were abnormal in molecular aspects due to its haploinsufficiency. In conclusion, this study provides straightforward supporting evidence in a way of reverse genetics for "two-hit hypothesis" in the Rb tumorigenesis and opens new avenues for development of early intervention and treatment of Rb.

Diverse mutational spectrum in the 13q14 chromosomal region in a Brazilian cohort of retinoblastoma

Retinoblastoma is a rare childhood tumor caused by the inactivation of both copies of the RB1 gene. Early diagnosis and identification of heritable RB1 mutation carriers can improve the disease outcome and management via genetic counseling. We used the Multiplex Ligation-dependent Probe Amplification (MLPA) method to analyze the RB1 gene and flanking regions in blood samples from 159 retinoblastoma patients previously negative for RB1 point mutations via Sanger sequencing. We detected a wide spectrum of germline chromosomal alterations, ranging from partial loss or duplication of RB1 to large deletions spanning RB1 and adjacent genes. Mutations were validated via karyotyping, fluorescent in situ hybridization (FISH), SNP-arrays (Single Nucleotide Polymorphism-arrays) and/or quantitative relative real-time PCR. Patients with leukocoria as a presenting symptom showed reduced death rate (p = 0.013) and this sign occurred more frequently among carriers of two breakpoints within RB1 (p = 0.05). All unilateral cases presented both breakpoints outside of RB1 (p = 0.0075). Patients with one breakpoint within RB1 were diagnosed at earlier ages (p = 0.017). Our findings characterize the mutational spectrum of a Brazilian cohort of retinoblastoma patients and point to a possible relationship between the mutation breakpoint location and tumor outcome, contributing to a better prospect of the genotype/phenotype correlation and adding to the wide diversity of germline mutations involving RB1 and adjacent regions in retinoblastoma.

Hallmarks of Cancer Applied to Oral and Oropharyngeal Carcinogenesis: A Scoping Review of the Evidence Gaps Found in Published Systematic Reviews

Simple Summary

This scoping review of systematic reviews aims to accurately assess the degree of existing scientific evidence on the cancer hallmarks proposed in 2011 by Hanahan and Weinberg, in the form of systematic reviews and meta-analyses, applied to oral potentially malignant disorders, oral cavity and oropharyngeal squamous cell carcinomas, in order to point out gaps in evidence and lines of research that should be implemented in the future to improve the malignant transformation prediction, diagnosis and/or prognosis of these diseases.

Abstract

In 2000 and 2011, Hanahan and Weinberg published two papers in which they defined the characteristics that cells must fulfil in order to be considered neoplastic cells in all types of tumours that affect humans, which the authors called “hallmarks of cancer”. These papers have represented a milestone in our understanding of the biology of many types of cancers and have made it possible to reach high levels of scientific evidence in relation to the prognostic impact that these hallmarks have on different tumour types. However, to date, there is no study that globally analyses evidence-based knowledge on the importance of these hallmarks in oral and oropharyngeal squamous cell carcinomas. For this reason, we set out to conduct this scoping review of systematic reviews with the aim of detecting evidence gaps in relation to the relevance of the cancer hallmarks proposed by Hanahan and Weinberg in oral and oropharyngeal cancer, and oral potentially malignant disorders, and to point out future lines of research in this field.

UBE2T/STAT3 Signaling Promotes the Proliferation and Tumorigenesis in Retinoblastoma

Purpose

The purpose of this paper was to investigate the expression and function of Ubiquitin-conjugating enzyme 2T (UBE2T), a human E2 ubiquitin-conjugating enzyme, in human retinoblastoma.

Methods

The expression of UBE2T in normal retina and retinoblastoma was analyzed using the Gene Expression Omnibus (GEO) databases, and its expression was immunohistochemically evaluated in 29 retinoblastoma sections and 5 normal retinas. Then CCK-8, flow cytometry, RNA-sequencing analysis, and in vivo assays were performed to explore the exact role of UBE2T in retinoblastoma.

Results

We found that retinoblastoma showed higher UBE2T expression than normal retina in GEO datasets and tissues. The immunoreactive score of UBE2T ≥4 was associated with group E in IIRC, T2-T4b in pTNM staging, poorly differentiated retinoblastoma, and high-risk histopathological factors. Knockdown of UBE2T reduced the cell viability, increased the apoptosis cells and G0/G1 cells, and inhibited subcutaneous tumor growth in vivo. Mechanistic studies showed that UBE2T knockdown induced down-regulation of phosphorylation of STAT3 and its downstream genes in vitro and in vivo. Rescue assays confirmed that STAT3 signaling pathway was involved in the effect of reduced cell viability, elevated apoptosis cells, and G0/G1 cells mediated by UBE2T knockdown.

Conclusions

Our data indicate that UBE2T significantly participates in the proliferation of retinoblastoma via the STAT3 signaling pathway, suggesting the potential of UBE2T as a therapeutic target for retinoblastoma treatment.

The Global Retinoblastoma Outcome Study: a prospective, cluster-based analysis of 4064 patients from 149 countries

Background

Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival.

Methods

We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models.

Findings

The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope).

Interpretation

This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.

Funding

Queen Elizabeth Diamond Jubilee Trust.

An immature, dedifferentiated, and lineage-deconstrained cone precursor origin of N-Myc-initiated retinoblastoma

Most retinoblastomas develop from maturing cone precursors in response to biallelic RB1 loss and are dependent on cone maturation-related signaling. Additionally, ∼2% lack RB1 mutations but have MYCN amplification (MYCN^A), N-Myc protein overexpression, and more rapid and invasive growth, yet the MYCN^A retinoblastoma cell of origin and basis for its responses to deregulated N-Myc are unknown. Here, using explanted cultured retinae, we show that ectopic N-Myc induces cell cycle entry in cells expressing markers of several retinal types yet induces continuous proliferation and tumorigenesis only in cone precursors. Unlike the response to RB1 loss, both immature cone arrestin-negative (ARR3^-) and maturing ARR3⁺ cone precursors proliferate, and maturing cone precursors rapidly dedifferentiate, losing ARR3 as well as L/M-opsin expression. N-Myc-overexpressing retinal cells also lose cell lineage constraints, occasionally coexpressing the cone-specific RXRγ with the rod-specific NRL or amacrine-specific AP2α and widely coexpressing RXRγ with the progenitor and Müller cell-specific SOX9 and retinal ganglion cell-specific BRN3 and GAP43. Mechanistically, N-Myc induced Cyclin D2 and CDK4 overexpression, pRB phosphorylation, and SOX9-dependent proliferation without a retinoma-like stage that characterizes pRB-deficient retinoblastoma, despite continuous p16^INK4A expression. Orthotopic xenografts of N-Myc-overexpressing retinal cells formed tumors with retinal cell marker expression similar to those in MYCN-transduced retinae and MYCN^A retinoblastomas in patients. These findings demonstrate the MYCN^A retinoblastoma origin from immature and lineage-deconstrained cone precursors, reveal their opportunistic use of an undifferentiated retinal progenitor cell feature, and illustrate that different cancer-initiating mutations cooperate with distinct developmental stage-specific cell signaling circuitries to drive retinoblastoma tumorigenesis.

Lactoferrin and its nano-formulations in rare eye diseases

Lactoferrin (LF) is an iron-binding glycoprotein released from mucous secreting cells and neutrophils. LF can be used in a broad range of eye diseases related to the retina, cornea, and optic nerve. The retina is particularly affected by oxidative stress inside the photoreceptor being constantly exposed to light which induces accumulation of reactive oxygen species (ROS) in the retinal pigmented epithelium (RPE) causing damage to photoreceptor recycling. Retinitis pigmentosa (RP) and macular degeneration are inherited retinopathies that consist of different disease-causing genes, that cause mutations with highly varied clinical consequences. Age-related macular degeneration is a chronic disease of the retina and one of the major causes of sight loss. This review provides an application of lactoferrin and LF-based nano-formulations or nanoparticles in the field of retinal diseases or corneal diseases such as retinitis pigmentosa, retinoblastoma, age-related macular degeneration (AMD), keratoconus and uveitis. Several studies have found that lactoferrin's antibacterial activity is not limited to its iron sequestration, but also its ability as a nanoparticle that acts as a carrier to deliver drugs by crossing the blood-retina barrier (BRB) and its involvement in cell cycle control, which is not possible by many transferrin proteins.

The Critical Role of Ferroptosis in Hepatocellular Carcinoma

Liver cancer is the sixth most frequently diagnosed cancer and the third dominant cause of cancer death worldwide. Ferroptosis is characterized as an iron-dependent form of regulated cell death, with accumulation of lipid peroxides to lethal amounts. Evidences have showed that ferroptosis is closely associated with HCC, but the mechanisms are still poorly understood. In this review, we mainly summarize the roles of several typical molecules as well as radiotherapy in regulating the ferroptosis process in HCC. Chances are that this review may help address specific issues in the treatment of HCC.

pRB-Depleted Pluripotent Stem Cell Retinal Organoids Recapitulate Cell State Transitions of Retinoblastoma Development and Suggest an Important Role for pRB in Retinal Cell Differentiation

Retinoblastoma (Rb) is a childhood cancer of the developing retina, accounting for up to 17% of all tumors in infancy. To gain insights into the transcriptional events of cell state transitions during Rb development, we established 2 disease models via retinal organoid differentiation of a pRB (retinoblastoma protein)-depleted human embryonic stem cell line (RB1-null hESCs) and a pRB patient-specific induced pluripotent (iPSC) line harboring a RB1 biallelic mutation (c.2082delC). Both models were characterized by pRB depletion and accumulation of retinal progenitor cells at the expense of amacrine, horizontal and retinal ganglion cells, which suggests an important role for pRB in differentiation of these cell lineages. Importantly, a significant increase in the fraction of proliferating cone precursors (RXRγ+Ki67+) was observed in both pRB-depleted organoid models, which were defined as Rb-like clusters by single-cell RNA-Seq analysis. The pRB-depleted retinal organoids displayed similar features to Rb tumors, including mitochondrial cristae aberrations and rosette-like structures, and were able to undergo cell growth in an anchorage-independent manner, indicative of cell transformation in vitro. In both models, the Rb cones expressed retinal ganglion and horizontal cell markers, a novel finding, which could help to better characterize these tumors with possible therapeutic implications. Application of Melphalan, Topotecan, and TW-37 led to a significant reduction in the fraction of Rb proliferating cone precursors, validating the suitability of these in vitro models for testing novel therapeutics for Rb.

Hypermethylation of RAD9A intron 2 in childhood cancer patients, leukemia and tumor cell lines suggest a role for oncogenic transformation

Most childhood cancers occur sporadically and cannot be explained by an inherited mutation or an unhealthy lifestyle. However, risk factors might trigger the oncogenic transformation of cells. Among other regulatory signals, hypermethylation of RAD9A intron 2 is responsible for the increased expression of RAD9A protein, which may play a role in oncogenic transformation. Here, we analyzed the RAD9A intron 2 methylation in primary fibroblasts of 20 patients with primary cancer in childhood and second primary cancer (2N) later in life, 20 matched patients with only one primary cancer in childhood (1N) and 20 matched cancer-free controls (0N), using bisulfite pyrosequencing and deep bisulfite sequencing (DBS). Four 1N patients and one 2N patient displayed elevated mean methylation levels (≥ 10 %) of RAD9A. DBS revealed ≥ 2 % hypermethylated alleles of RAD9A, indicative for constitutive mosaic epimutations. Bone marrow samples of NHL and AML tumor patients (n=74), EBV (Epstein Barr Virus) lymphoblasts (n=6), tumor cell lines (n=5) and FaDu subclones (n=13) were analyzed to substantiate our findings. We find a broad spectrum of tumor entities with an aberrant methylation of RAD9A. We detected a significant difference in mean methylation of RAD9A for NHL versus AML patients (p ≤0.025). Molecular karyotyping of AML samples during therapy with hypermethylated RAD9A showed an evolving duplication of 1.8 kb on Chr16p13.3 including the PKD1 gene. Radiation, colony formation assays, cell proliferation, PCR and molecular karyotyping SNP-array experiments using generated FaDu subclones suggest that hypermethylation of RAD9A intron 2 is associated with genomic imbalances in regions with tumor-relevant genes and survival of the cells. In conclusion, this is the very first study of RAD9A intron 2 methylation in childhood cancer and Leukemia. RAD9A epimutations may have an impact on leukemia and tumorigenesis and can potentially serve as a biomarker.

Retinoblastoma: emerging concepts in genetics, global disease burden, chemotherapy outcomes, and psychological impact

In this review we discuss several recent concepts regarding retinoblastoma control and its impact. In a cohort of 482 patients with solitary unilateral retinoblastoma revealed germline mutation in 16% and the likelihood of germline retinoblastoma was greater for younger children (≤1 year versus (vs.) >1 year at presentation) with odds ratio (OR) 2.96 (p = 0.001), and greatest for the youngest infants (≤3 months vs. >3-12 months) (OR 5.52) (p = 0.002). Retinocytoma/retinoma, a benign variant of retinoblastoma, was studied in 78 tumours and demonstrated transformation into retinoblastoma in 9.2% by 5 years and 15.3% by 10 years and 20 years. An international global study on retinoblastoma over 1.5 years revealed 4351 new patients and 85% from low- and middle-income countries, notably with older age at detection and greater risk for metastasis. Management of retinoblastoma in 964 eyes using intravenous chemotherapy showed 20-year globe salvage at 96% in group A, 90% in group B, 90% in group C, 68% in group D, and 32% in group E eyes. The 5-year globe salvage with intra-arterial chemotherapy for 160 eyes (655 infusions) with retinoblastoma showed success in 100% for group B, 80% for group C, 78% for group D, and 55% for group E. The psychological impact of retinoblastoma on the parents revealed depression (73%), anxiety (64%), and/or stress (100%), and on the patient revealed deficits in quality of life issues. Retinoblastoma is a challenging disease and chemotherapy provides reliable tumour control and globe salvage. Continuing efforts to improve quality of life issues is important.

Association of MTHFR 677C > T, 1298A > C and MTR 2756A > G Polymorphisms with Susceptibility to Childhood Retinoblastoma: A Systematic Review and Met-Analysis

BackgroundRecently, epidemiological studies investigating the association of MTHFR 677 C > T, 1298 A > C and MTR 2756 A > G polymorphism with retinoblastoma susceptibility reported controversial results. Methods: Data were collected from several electronic databases such as PubMed, EMBASE, and Google Scholar databases, with the last search up to December 05, 2019. Results: A total of eleven case-control studies including four studies with 324 cases and 490 controls on MTHFR 677 C > T, four studies with 324 cases and 490 controls on MTHFR 1298 A > C, and three studies with 283 cases and 485 controls on MTR 2756 A > G were selected. There was a significant association between MTHFR 677 C > T and MTR 2756 A > G polymorphisms and an increased risk of retinoblastoma. However, MTHFR 1298 A > C polymorphism was not significantly associated with risk of retinoblastoma. Conclusion: This meta-analysis demonstrated that MTHFR 677 C > T and MTR 2756 A > G polymorphisms might play important roles in the development of retinoblastoma. No association with MTHFR 1298 A > C polymorphism was observed.

Anticancer Activity of New Na(I) Complex on Retinoblastoma Cells via Inhibiting PI3K/AKT/mTOR Pathway

Here, through applying 2,6-bis(4'-carboxyl-phenyl)pyridine (H2L), a rigid ligand featuring both carboxylic acid and pyridine groups, a new coordination polymer containing Na(I) has been generated with the reaction between H2L ligand and NaNO3 in a water and DMF mixed solvent, and its chemical composition is [Na2L]n. Furthermore, the antiproliferative activity of Na(I) complex against the HXO-Rb44 retinoblastoma cells was detected with CCK-8 assay. Hoechst staining along with Annexin V-FITC/PI revealed that Na(I) complex induces the HXO-Rb44 retinoblastoma cells apoptosis. Flow cytometry analysis of reactive oxygen species (ROS) showed that Na(I) complex significantly increases the level of intracellular ROS. Importantly, western blot analysis revealed that Na(I) complex might induce apoptosis through inactivation of PI3K/AKT/mTOR pathway.

The Oncogene MYCN Modulates Glycolytic and Invasive Genes to Enhance Cell Viability and Migration in Human Retinoblastoma

Retinoblastoma is usually initiated by biallelic RB1 gene inactivation. In addition, MYCN copy number alterations also contribute to RB pathogenesis. However, MYCN expression, its role in disease progression and correlation with RB histological risk factors are not well understood. We studied the expression of MYCN in enucleated RB patient specimens by immunohistochemistry. MYCN is overexpressed in RB compared to control retina. Our microarray gene expression analysis followed by qRT-PCR validation revealed that genes involved in glucose metabolism and migration are significantly downregulated in MYCN knockdown cells. Further, targeting MYCN in RB cells using small molecule compounds or shRNAs led to decreased cell survival and migration, increased apoptosis and cell cycle arrest, suggesting that MYCN inhibition can be a potential therapeutic strategy. We also noted that MYCN inhibition results in reduction in glucose uptake, lactate production, ROS levels and gelatinolytic activity of active-MMP9, explaining a possible mechanism of MYCN in RB. Taking clues from our findings, we tested a combination treatment of RB cells with carboplatin and MYCN inhibitors to find enhanced therapeutic efficacy compared to single drug treatment. Thus, MYCN inhibition can be a potential therapeutic strategy in combination with existing chemotherapy drugs to restrict tumor cell growth in RB.

Identification of novel RB1 genetic variants in Retinoblastoma patients and their impact on clinical outcome

BACKGROUND

Retinoblastoma (RB) is an intraocular childhood cancer develops due to inactivation of RB1 gene. Identification of RB1 genetic variants, correlating and confirming genetic test results with clinical outcomes are crucial for effective RB management.

METHODS

Retrospective study of 62 RB patients and 14 family members who underwent genetic testing either by next generation sequencing (NGS) or multiplex ligation-dependent probe amplification (MLPA) or by both for screening RB1 germline mutations present in peripheral blood. Mutational outcomes were correlated with clinical outcomes evaluated over a follow-up period of 12 months.

RESULTS

Of the 62 patients, 35 (56%) had bilateral RB and 27 (44%) had unilateral RB. Out of 24 (52%) variants detected by NGS, 9 (37.5%) were novel and 15 (62.5%) were known in 46 probands. Six (18%) gross deletions were detected by MLPA in 34 probands. The mutation detection rate by NGS and MLPA in unilateral cases was 15% (n = 4) and 74% (n = 26) in bilateral cases. In patients with RB1 genetic mutations versus those without, the rate of primary enucleation (7 (12%) vs 18 (44%) eyes; p = .0008) was inversely proportional to tumor recurrence (25 (45%) vs 6 (15%) eyes; p = .002). There was no difference in the rate of globe salvage and metastasis, over a mean follow-up period of 12 months.

CONCLUSION

The mutations screening is important for risk assessment in future siblings and offspring of RB patients and most important in unilateral RB for determining if hereditary or not hereditary RB. Its role in predicting clinical outcomes is yet to be determined.

Parental Origin of the RB1 Gene Mutations in Families with Low Penetrance Hereditary Retinoblastoma

Simple Summary

Some families with hereditary retinoblastoma exhibit mild phenotype with low penetrance and variable expressivity, including complete absence of clinical signs of the disease in some carriers of the germline RB1 mutation. The identification of low-penetrance mutations in the RB1 gene and the study of their inheritance in pedigrees is contributing to understanding the mechanisms underlying the development of retinoblastoma with low penetrance. It is important both for further expansion of knowledge in the field of molecular genetics of retinoblastoma, and for competent genetic counseling and subsequent clinical management of families with this form of the disease. Our results support an assumption that parental origin of an RB1 mutation influences the likelihood of developing retinoblastoma. We also revealed a relatively high frequency of asymptomatic carriage of the RB1 mutations among the parents of retinoblastoma patients, highlighting the utmost necessity for molecular analysis among the probands’ relatives irrespective of their clinical status and family history of retinoblastoma.

Abstract

Our aim was to identify RB1 alterations causing hereditary low penetrance retinoblastoma and to evaluate how the parental origin of an RB1 mutation affects its phenotypic expression. By NGS and MLPA, RB1 mutations were found in 191 from 332 unrelated retinoblastoma patients. Among patients with identified RB1 mutations but without clinical family history of retinoblastoma, 7% (12/175) were found to have hereditary disease with one of the parents being an asymptomatic carrier of an RB1 mutation. Additionally, in two families with retinoblastoma history, mutations were inherited by probands from unaffected parents. Overall, nine probands inherited RB1 mutations from clinically unaffected fathers and five, from mothers. Yet, we gained explanations of maternal “unaffectedness” in most cases, either as somatic mosaicism or as clinical presentation of retinomas in involution, rendering the proportion of paternal to maternal truly asymptomatic mutation carriers as 9:1 (p = 0.005). This observation supports an assumption that parental origin of an RB1 mutation influences the likelihood of developing retinoblastoma. Additionally, our study revealed a relatively high frequency of asymptomatic carriage of the RB1 mutations among the parents of retinoblastoma patients, highlighting the utmost necessity of molecular analysis among the probands’ relatives irrespective of their clinical status and family history of retinoblastoma.

A high-risk retinoblastoma subtype with stemness features, dedifferentiated cone states and neuronal/ganglion cell gene expression

Retinoblastoma is the most frequent intraocular malignancy in children, originating from a maturing cone precursor in the developing retina. Little is known on the molecular basis underlying the biological and clinical behavior of this cancer. Here, using multi-omics data, we demonstrate the existence of two retinoblastoma subtypes. Subtype 1, of earlier onset, includes most of the heritable forms. It harbors few genetic alterations other than the initiating RB1 inactivation and corresponds to differentiated tumors expressing mature cone markers. By contrast, subtype 2 tumors harbor frequent recurrent genetic alterations including MYCN-amplification. They express markers of less differentiated cone together with neuronal/ganglion cell markers with marked inter- and intra-tumor heterogeneity. The cone dedifferentiation in subtype 2 is associated with stemness features including low immune and interferon response, E2F and MYC/MYCN activation and a higher propensity for metastasis. The recognition of these two subtypes, one maintaining a cone-differentiated state, and the other, more aggressive, associated with cone dedifferentiation and expression of neuronal markers, opens up important biological and clinical perspectives for retinoblastomas.