Current update on retinoblastoma

Retinoblastoma survival and enucleation outcomes in 41 countries from the African continent

BACKGROUND

Retinoblastoma is the most common intraocular malignancy in childhood. Despite one-third of cases occurring in Africa, little is known of the outcomes on the continent. This study aims to explore survival and globe salvage outcomes and identify their risk factors across a large cohort of patients from the African continent.

METHODS

A 3-year prospective, observational study was conducted. Kaplan-Meier survival analysis was used to investigate the risk of globe loss and death from retinoblastoma in Africa. Cox regression was used to identify risk factors associated with these outcomes.

RESULTS

A total of 958 patients from 41 African countries and 66 participating centres were enrolled in the study. The survival rate was 78.2% at 1 year and 66.2% at 3 years after diagnosis. Cox regression showed a higher risk of death with the most advanced clinical stage (cT4, HR=6.29 vs cT2, p<0.001). The risk of losing at least one eye after diagnosis was 50% within 4 months and 72.6% within 3 years. Higher risk of enucleation was associated with a higher clinical stage compared with cT1 (cT3, HR=4.11, p=0.001; cT4, HR=3.77, p=0.005).

CONCLUSION

Nearly one in every four children diagnosed with retinoblastoma in African participating centres succumb to retinoblastoma within 1 year. There is also high morbidity associated with the diagnosis as a large majority of patients require eye removal surgery. The outcome of disease in children with retinoblastoma in Africa is poor compared with other continents and requires prompt intervention by increasing efforts to improve survival and eye salvage outcomes.

Demographic and Clinical Characteristics of Retinoblastoma Cases at a Tertiary Care Center in Eastern India

OBJECTIVE

This study aims to evaluate the burden, demographic profile, clinical characteristics, and management of retinoblastoma (RB) cases at a tertiary care center.

MATERIAL AND METHODS

This was a hospital-based study conducted in a tertiary care center in the Department of Ophthalmology from January 2018 to December 2022. All referred and newly diagnosed cases of RB coming to the outpatient department were included in the study after obtaining written informed consent from parents or guardians. Data collected were analyzed in terms of demographic profile, socioeconomic status, and clinical characteristics of the disease at the time of presentation and its treatment.

RESULTS

Out of 155,671 new patients seen in the outpatient eye department during the study period, 118 eyes of 94 patients were diagnosed with RB. The burden of disease was found to be 60.4 cases per 100,000 patients. Malignancy was unilateral in 74.47% and bilateral in 25.53% of cases. The male-to-female ratio was 1.7:1. The mean age at presentation was 30.86±19.5 months. A family history of RB was seen in 4.26% of cases. Of the patients, 80.85% belonged to upper-lower socioeconomic status. Most of the cases presented to us at an advanced stage of the disease (i.e., groups E and D).

CONCLUSION

Most of our cases present at an advanced stage of RB, resulting in poor outcomes and survival rates. It is necessary to organize awareness campaigns about the fatal nature of the disease so it can be diagnosed early, leading to better visual and survival outcomes.

Advances in the treatment of intraocular malignancies: A literature review

Intraocular malignant tumors including primary and metastatic tumors, are mainly found in Retina and uvea, and very few cases originate from the sclera and optic nerve. Intraocular tumors can endanger the patient's vision and even life, and proper treatment is vital. There have been several traditional treatments for intraocular tumors, such as radiotherapy, chemotherapy and surgery. In recent years, new methods have been developed in clinical applications including anti-VEGF and gene therapy. This paper aims to provide a timely review about recent progress in the treatment of intraocular malignant tumor.

Nanotechnology for Pediatric Retinoblastoma Therapy

Retinoblastoma is a rare, sometimes hereditary, pediatric cancer. In high-income countries this disease has a survival rate approaching 100%, while in low- and middle-income countries the prognosis is fatal for about 80% of cases. Depending on the stage of the disease, different therapeutic protocols are applied. In more advanced forms of the disease, surgical removal of the entire globe and its intraocular contents (enucleation) is, unfortunately, necessary, whereas in other cases, conventional chemotherapy is normally used. To overcome the side-effects and reduced efficacy of traditional chemotherapic drugs, nanodelivery systems that ensure a sustained drug release and manage to reach the target site have more recently been developed. This review takes into account the current use and advances of nanomedicine in the treatment of retinoblastoma and discusses nanoparticulate formulations that contain conventional drugs and natural products. In addition, future developments in retinoblastoma treatment are discussed.

Ruptured retinoblastoma: management in a rare case scenario

A preschool child presented with white reflex in left eye since 2 months. Examination under anaesthesia revealed left eye retinoblastoma group D as per international classification of retinoblastoma. In collaboration with medical oncologist, systemic chemotherapy was started. After two cycles of systemic chemotherapy, tumour ruptured into the vitreous cavity suspending the tumour cells in the vitreous jelly. After a combination of systemic and intravitreal chemotherapy with adjuvant transpupillary thermotherapy of the residual retinal tumour, retinoblastoma regressed completely with corresponding flat scar.

Protein Profiling of WERI-RB1 and Etoposide-Resistant WERI-ETOR Reveals New Insights into Topoisomerase Inhibitor Resistance in Retinoblastoma

Chemotherapy resistance is one of the reasons for eye loss in patients with retinoblastoma (RB). RB chemotherapy resistance has been studied in different cell culture models, such as WERI-RB1. In addition, chemotherapy-resistant RB subclones, such as the etoposide-resistant WERI-ETOR cell line have been established to improve the understanding of chemotherapy resistance in RB. The objective of this study was to characterize cell line models of an etoposide-sensitive WERI-RB1 and its etoposide-resistant subclone, WERI-ETOR, by proteomic analysis. Subsequently, quantitative proteomics data served for correlation analysis with known drug perturbation profiles. Methodically, WERI-RB1 and WERI-ETOR were cultured, and prepared for quantitative mass spectrometry (MS). This was carried out in a data-independent acquisition (DIA) mode. The raw SWATH (sequential window acquisition of all theoretical mass spectra) files were processed using neural networks in a library-free mode along with machine-learning algorithms. Pathway-enrichment analysis was performed using the REACTOME-pathway resource, and correlated to the molecular signature database (MSigDB) hallmark gene set collections for functional annotation. Furthermore, a drug-connectivity analysis using the L1000 database was carried out to associate the mechanism of action (MOA) for different anticancer reagents to WERI-RB1/WERI-ETOR signatures. A total of 4756 proteins were identified across all samples, showing a distinct clustering between the groups. Of these proteins, 64 were significantly altered (q < 0.05 & log2FC |>2|, 22 higher in WERI-ETOR). Pathway analysis revealed the “retinoid metabolism and transport” pathway as an enriched metabolic pathway in WERI-ETOR cells, while the “sphingolipid de novo biosynthesis” pathway was identified in the WERI-RB1 cell line. In addition, this study revealed similar protein signatures of topoisomerase inhibitors in WERI-ETOR cells as well as ATPase inhibitors, acetylcholine receptor antagonists, and vascular endothelial growth factor receptor (VEGFR) inhibitors in the WERI-RB1 cell line. In this study, WERI-RB1 and WERI-ETOR were analyzed as a cell line model for chemotherapy resistance in RB using data-independent MS. Analysis of the global proteome identified activation of “sphingolipid de novo biosynthesis” in WERI-RB1, and revealed future potential treatment options for etoposide resistance in RB.

Clinicoepidemiological Profile and Treatment Outcomes in Children with Retinoblastoma: Experience from a Cancer Care Center in Northeast India

Gaurav KumarBackground  Retinoblastoma (RB) is the most common primary intraocular malignancy in children. We sought to provide a comprehensive assessment of epidemiological profile and treatment outcomes of children with RB. Methods  In this retrospective study, we analyzed 189 children diagnosed with RB at our center between 2004 and 2017. Survival was analyzed with the Kaplan-Meier method and log-rank test. Results  Median age at presentation was 14 months with male: female ratio 1.2:1. Mean duration between onset of symptoms and presentation was 49 days (standard deviation ± 79). Most common presenting symptom was white pupillary reflex in 60% of children. Family history of RB and other cancers was found in one (0.5%) and seven (4%) children, respectively. Primary mode of diagnosis and staging was ocular ultrasonography (bone scan) in 87% of patients. Computed tomographic scan and magnetic resonance imaging were done in 124 (66%) and 30 (16%) patients, respectively. International staging system grade E disease was found in 144 (76%), extraocular disease in 55 (29%), bilateral disease in 49 (26%), and trilateral disease in 3 (1.5%) children. Out of 189 children with RB, 33 (18%) refused treatment and 156 children received treatment (24 children [15%] abandoned treatment midway and 132 [85%] completed treatment). One hundred children (64%) received systemic therapy as neoadjuvant or adjuvant chemotherapy and 20 (13%) received local therapy. Eyeball and vision salvage rate with chemotherapy were 20 (13%) and 9 (6%), respectively. Cryotherapy was the most common modality of local treatment used in 11 (55%) children. Five-year survival for patients who received treatment was 76% (median survival not reached). In the treatment refusal group, median survival was 9 months. Conclusion  In developing countries, RB is mostly detected in advanced stages resulting in poor outcomes. Increased awareness and accessibility to dedicated centers for treating childhood malignancy can lead to early diagnosis, better prognosis, and increased vision salvage.

AN IN VIVO STUDY OF INTRAVITREAL RANIBIZUMAB FOLLOWING SUBRETINAL INOCULATION OF RB CELLS IN RABBITS EYES

AIM

This study aimed to determine the effects of a single intravitreal ranibizumab injection in rabbits induced with retinoblastoma (RB).

MATERIAL AND METHODS

RB was induced in six New Zealand white rabbits by subretinal injection of a cultured WERI-RBb-1 cell line into the right eye. After six weeks, Group A (n = 3) was given intravitreal ranibizumab injection (0.3mg in 0.03ml) and Group B (n = 3) was the control. Baseline and serial clinical examinations were performed on days 1, 3, 6, 12, 15, 18 and 21. The right eyes were enucleated for both groups on day 21 for histopathological examination.

RESULTS

The rabbits in both groups developed intraocular lesions which was detectable clinically at one-week post-tumor inoculation. The tumor grew slowly without spontaneous regression. After the animals in Group A were given an intravitreal ranibizumab injection, regression of the tumor was detected clinically, while the tumor in Group B continued to grow slowly. Histopathological findings confirmed the presence of a tumor that closely resembled features of poorly differentiated human RB cells. At the end of 21 days, the size of the tumor was larger in Group B in comparison to Group A. However, the treated group also developed a focal area of retinal hyperplasia. There was no significant side effect of ranibizumab injection except temporary high intraocular pressure immediately post-injection, which was relieved after paracentesis.

CONCLUSIONS

Intravitreal ranibizumab is a potential treatment for RB. It is an effective therapy with a tolerable safety profile in this animal experimental study.

Ribonucleotide reductase subunit M2 promotes proliferation and epithelial-mesenchymal transition via the JAK2/STAT3 signaling pathway in retinoblastoma

Retinoblastoma (RB) is an intraocular malignant tumor that often occurs in children. Along with the improvement of treatment strategies, the cure rate of RB has increased significantly. However, the treatment of advanced and recurrent RB remains as a critical challenge. Therefore, studying the molecular mechanisms underlying the progression of RB is essential for the development of novel and effective therapeutic strategies. Through the analysis of a previously published microarray study, we found that ribonucleotide reductase subunit M2 (RRM2) was highly expressed in RB tissues as compared to normal tissues. The purpose of this study is to clarify the role and mechanism of RRM2 in regulating the progression of RB. We first demonstrated that RRM2 expression level in RB tissues and cell lines was significantly higher when compared to that in normal retinal tissue and cell lines, and high RRM2 expression level was associated with a poorer overall survival of patients. In RB cells, RRM2 overexpression promoted cell proliferation, migration, invasion and epithelial-mesenchymal transformation (EMT), while RRM2 silencing suppressed these biological features. Silencing RRM2 reduced the activation of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, and the presence of JAK2/STAT3 signaling pathway inhibitor INCB attenuated the effect of RRM2 overexpression. Collectively, our data indicate that RRM2 promotes the progression of RB by activating JAK2/STAT3 signaling pathway. Targeting RRM2/JAK2/STAT3 axis lays a theoretical foundation for the formulation of novel RB therapy.

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.

MicroRNA-9 inhibits proliferation and progression in retinoblastoma cells by targeting PTEN

BACKGROUND

Retinoblastoma (RB) is the most prevalent primary intraocular malignancy, which commonly occurs during infant and childhood.

OBJECTIVE

Our study aimed to investigate whether microRNA-9 (miR-9) could regulate RB cells and its mechanism.

METHODS

qRT-PCR analysis was used to detect the expression of miR-9. In addition, to detect the migration of RB cells, wound healing assay was conducted. Xenograft tumor models in nude mice were also established, in order to assess the effects of miR-9 on tumor growth. qRT-PCR, luciferase reporter assay and western blot analysis were used to detect the target of miR-9.

RESULTS

Initially, the expression level of miR-9 was significantly decreased in the RB tissues and blood samples from patients with RB. qRT-PCR, luciferase reporter assay and western blot analysis were used to confirm that PTEN was the target genes of miR-9 and it was negatively regulated by miR-9. When the expression of miR-9 was up-regulated, the cell viability, proliferation, migration and tumor formation were significantly suppressed. Furthermore, the expression level of PTEN was decreased after transfection of miR-9 mimic. Taken together, these results indicated that miR-9 might suppress the cell viability, proliferation, migration and tumor formation in RB by inhibiting PTEN.

CONCLUSION

The in vitro and in vivo experiments demonstrated that miR-9 acts as a tumor suppressor function in RB cells and might serve as novel therapeutic targets for the treatment of RB.

Potential Therapeutic Targets of Quercetin, a Plant Flavonol, and Its Role in the Therapy of Various Types of Cancer through the Modulation of Various Cell Signaling Pathways

Polyphenolic flavonoids are considered natural, non-toxic chemopreventers, which are most commonly derived from plants, fruits, and vegetables. Most of these polyphenolics exhibit remarkable antioxidant, anti-inflammatory, and anticancer properties. Quercetin (Qu) is a chief representative of these polyphenolic compounds, which exhibits excellent antioxidant and anticancer potential, and has attracted the attention of researchers working in the area of cancer biology. Qu can regulate numerous tumor-related activities, such as oxidative stress, angiogenesis, cell cycle, tumor necrosis factor, proliferation, apoptosis, and metastasis. The anticancer properties of Qu mainly occur through the modulation of vascular endothelial growth factor (VEGF), apoptosis, phosphatidyl inositol-3-kinase (P13K)/Akt (proteinase-kinase B)/mTOR (mammalian target of rapamycin), MAPK (mitogen activated protein kinase)/ERK1/2 (extracellular signal-regulated kinase 1/2), and Wnt/β-catenin signaling pathways. The anticancer potential of Qu is documented in numerous in vivo and in vitro studies, involving several animal models and cell lines. Remarkably, this phytochemical possesses toxic activities against cancerous cells only, with limited toxic effects on normal cells. In this review, we present extensive research investigations aimed to discuss the therapeutic potential of Qu in the management of different types of cancers. The anticancer potential of Qu is specifically discussed by focusing its ability to target specific molecular signaling, such as p53, epidermal growth factor receptor (EGFR), VEGF, signal transducer and activator of transcription (STAT), PI3K/Akt, and nuclear factor kappa B (NF-κB) pathways. The anticancer potential of Qu has gained remarkable interest, but the exact mechanism of its action remains unclear. However, this natural compound has great pharmacological potential; it is now believed to be a complementary-or alternative-medicine for the prevention and treatment of different cancers.

GD2-specific chimeric antigen receptor-modified T cells targeting retinoblastoma - assessing tumor and T cell interaction

A novel disialoganglioside 2 (GD2)-specific chimeric antigen receptor (CAR)-modified T cell therapy against retinoblastoma (RB) were generated. GD2-CAR consists of a single-chain variable fragment (scFv) derived from a monoclonal antibody, hu3F8, that is linked with the cytoplasmic signaling domains of CD28, 41BB, a CD3ζ, and an inducible caspase 9 death fusion partner. GD2 antigen is highly expressed in Y79RB cell line and in several surgical RB tumor specimens. In vitro co-culture experiments revealed the effective killing of Y79RB cells by GD2-CAR T cells, but not by control CD19-CAR T cells. The killing activities of GD2-CAR T cells were diminished when repeatedly exposed to the tumor, due to an attenuated expression of GD2 antigen on tumor cells and upregulation of inhibitory molecules of the PD1 and PD-L1 axis in the CAR T cells and RB tumor cells respectively. This is the first report to describe the potential of GD2-CAR T cells as a promising therapeutic strategy for RB with the indication of potential benefit of combination therapy with immune checkpoint inhibitors.

Management and Outcomes of Unilateral Group D Tumors in Retinoblastoma

Purpose

Retinoblastoma presents most commonly as advanced unilateral disease, particularly in developing countries for which primary enucleation has been the preferred method of treatment. However, with the evolution of newer treatment modalities including intravitreal chemotherapy, intra-arterial chemotherapy and newer chemotherapeutic combinations, a trend towards more conservative approaches is being observed. Our aim is to evaluate outcomes of group D eyes following conservative and non-conservative treatment options.

Patients and Methods

The ocular oncology database was used to identify eyes with unilateral retinoblastoma that fulfilled the International Intraocular Retinoblastoma Classification (IIRC) group D criteria from August 2010 to August 2018 and these were retrospectively reviewed. Overall, 39 eyes were identified.

Results

Nineteen (49%) eyes underwent primary enucleation and 20 (51%) received eye-conserving treatment. Eye salvage was possible in 15 (75%) eyes in the attempted salvage group. None of the patient revealed signs of metastasis. All eyes received conventional chemotherapy (carboplatin, vincristine, etoposide) and focal laser therapy. Additional treatment modalities offered included intravitreal chemotherapy, intra-arterial chemotherapy and topotecan. Three (11%) eyes in the primary enucleation group showed high-risk features on histopathology and none developed metastasis.

Conclusion

The results of the study seem promising and conservative measures can be adopted in selected unilateral group D eyes.

Spectrum of germline mutations in RB1 in Chinese patients with retinoblastoma: Application of targeted next-generation sequencing

Purpose

Retinoblastoma (RB) is a pediatric ocular malignancy due to biallelic inactivation of the RB1 gene. Genetic testing is critically important for treatment decisions for this disease. Targeted next-generation sequencing (NGS) has been demonstrated to be an effective strategy for discovering all types of mutations in the RB1 gene. The aim of this study is the application of targeted NGS in a cohort of Chinese patients with retinoblastoma to identify germline mutations in the RB1 gene.

Methods

Blood samples were collected from 149 unrelated probands with retinoblastoma (62 bilaterally and 87 unilaterally) and their parent(s). Genomic DNA was analyzed with custom panel-based targeted NGS, and the panel was designed to include exons 1-27 of the RB1 gene with flanking intronic sequences. Single nucleotide variations (SNVs) and small insertions/deletions (InDels) identified were confirmed with Sanger sequencing. If the Sanger sequencing of a low-frequency variant (LFV) detected with targeted NGS was negative, PCR-based deep NGS was conducted for added confirmation. Copy number variations (CNVs) detected with targeted NGS were confirmed with multiplex ligation-dependent probe amplification (MLPA).

Results

Overall, 74 germline mutations were detected in 48.3% of the probands (72/149, 56 bilateral and 16 unilateral cases). The total detection rate in the bilateral cases was 90.3% (56/62). These mutations included 64 SNVs and InDels (25 nonsense, 20 splicing, ten frameshift, eight missense, and one synonymous variants) and ten CNVs. All CNVs were confirmed with MLPA. Twenty-four (32.4%, 24/74) variants detected were novel, including nine splicing, six frameshift, five missense, and four nonsense variants. Eight LFVs (10.8%, 8/74) were found with targeted NGS; six of which were identified with Sanger sequencing, and two were identified with PCR-based deep NGS (13.16% and 3.000% mutant rates, respectively).

Conclusions

This study expanded the spectrum of germline mutations in RB1 using targeted NGS technology, which is a cost-saving and efficient method for genetic sequencing of retinoblastoma and may improve the molecular diagnosis of retinoblastoma.

Socioeconomic status and retinoblastoma survival: Experience of a tertiary cancer center in Brazil

BACKGROUND

Little is known about socioeconomic status (SES) and its effects in childhood cancer survival. This study aims to discuss the association between SES and survival of patients with retinoblastoma (RB) from a tertiary treatment center.

PROCEDURE

A retrospective cohort study was conducted, including all patients with RB referred to the Brazilian National Institute of Cancer in Rio de Janeiro (January 2000-December 2016).

RESULTS

Data from 160 patients were analyzed with mean age at diagnosis of 22.85 months (SD ± 14.29). Eighty-three patients (51.9%) had an interval to diagnosis equal to or longer than six months, and 13 children (8.1%) abandoned treatment. Five-year overall survival rate for all patients was 78.8% (95% CI, 72.4%-85.9%). In a multivariate model, patients whose fathers had more than nine years of study had a lower death risk. Patients from families having more than one child under five years had a 213% higher risk of death compared with those living with no other small child. Treatment abandonment also had a profound effect on death risk.

CONCLUSION

Childhood cancer is notably important considering the potential years of life lost. RB has even more important elements, as the possibility of vision loss in cases with delayed diagnosis. Family characteristics seem to be highly related to RB survival, especially in low- and middle-income countries, where inequalities are still a public health issue. Strategies to improve survival should focus not only on large-scale settings such as improving national healthcare systems but also on more personalized actions that might help to mitigate disparities.

Dosimetric comparison of different radiotherapy techniques for the treatment of Retinoblastoma

Aim:

This study aims to compare the dosimetric parameters among four different external beam radiotherapy techniques used for the treatment of retinoblastoma.

Materials and methods:

Computed tomography (CT) sets of five retinoblastoma patients who required radiotherapy to one globe were included. Four different plans were generated for each patient using three dimensional conformal radiotherapy (3DCRT), intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and VMAT using flattening filter free (VMAT-FFF) beam techniques. Plans were compared for target coverage and organs at risk (OARs) sparing.

Results:

The target coverage of planning target volume (PTV) for all the four modalities were clinically acceptable with a V95 of 95 ± 0%, 97·6 ± 1·87%, 99·3 ± 0·5% and 99·17 ± 0·45% for 3DCRT, IMRT, VMAT and VMAT-FFF respectively. The VMAT and IMRT plans had better target coverage than the 3DCRT plans (p = 0·001 and p = 0·07 respectively). IMRT and VMAT plans were also found superior to 3DCRT plans in terms of OAR sparing like brainstem, optic chiasm, brain (p < 0·05). VMAT delivered significantly lower dose to the brainstem and contralateral optic nerve in comparison to IMRT. Use of VMAT-FFF beams did not show any benefit over VMAT in target coverage and OAR sparing.

Conclusion:

VMAT should be preferred over 3DCRT and IMRT for treatment of retinoblastoma owing to better target coverage and less dose to most of the OARs. However, IMRT and VMAT should be used with caution because of the increased low dose volumes to the OARs like contralateral lens and eyeball.

Leukocoria in a 2-Year-Old Patient With Atypical Optic Nerve Fiber Layer Myelination

Myelinated retinal nerve fiber layer is a benign retinal condition that is usually an incidental finding in a healthy patient. Visual acuity is typically not compromised, but some cases have other associated ocular conditions that can affect vision. Diagnosis in challenging atypical cases requires imaging studies to rule out other pathologies. The authors describe the case of a 2-year-old girl who presented with atypical optic nerve fiber myelination. [J Pediatr Ophthalmol Strabismus. 2020;57:e56-e58.].

The mouse double minute 2 309T>G polymorphism and retinoblastoma risk: A meta-analysis

PURPOSE

Mouse double minute 2 (MDM2) homolog is a protein that in humans is encoded by the MDM2 gene. It is expressed in retinoblastoma (Rb) cells and acts as a key negative regulator of the p53 tumor suppressor gene. Several studies have investigated the association of Rb with MDM2 309T>G polymorphism, but the results were conflicting. To derive a more precise estimation of the association, we performed a meta-analysis of the relationship between MDM2 309T>G polymorphism with Rb in all published studies.

METHODS

Published literature from PubMed and other databases were retrieved. All the reported studies evaluating the association between MDM2 309T>G polymorphism and Rb risk were included. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using the fixed-effect model. A total of four case-control studies, including 520 cases and 745 controls were included.

RESULTS

This meta-analysis found that MDM2 309T>G polymorphism was significantly associated with Rb risk in the dominant model, TG+GG versus TT (OR = 1.43, 95% CI = 1.11-1.84, P = 0.006).

CONCLUSION

The present meta-analysis suggested that MDM2 309T>G polymorphism has a significant association with increased Rb risk.

Expression Changes and Impact of the Extracellular Matrix on Etoposide Resistant Human Retinoblastoma Cell Lines

Retinoblastoma (RB) represents the most common malignant childhood eye tumor worldwide. Several studies indicate that the extracellular matrix (ECM) plays a crucial role in tumor growth and metastasis. Moreover, recent studies indicate that the ECM composition might influence the development of resistance to chemotherapy drugs. The objective of this study was to evaluate possible expression differences in the ECM compartment of the parental human cell lines WERI-RB1 (retinoblastoma 1) and Y79 and their Etoposide resistant subclones via polymerase chain reaction (PCR). Western blot analyses were performed to analyze protein levels. To explore the influence of ECM molecules on RB cell proliferation, death, and cluster formation, WERI-RB1 and resistant WERI-ETOR cells were cultivated on Fibronectin, Laminin, Tenascin-C, and Collagen IV and analyzed via time-lapse video microscopy as well as immunocytochemistry. We revealed a significantly reduced mRNA expression of the proteoglycans Brevican, Neurocan, and Versican in resistant WERI-ETOR compared to sensitive WERI-RB1 cells. Also, for the glycoproteins α1-Laminin, Fibronectin, Tenascin-C, and Tenascin-R as well as Collagen IV, reduced expression levels were observed in WERI-ETOR. Furthermore, a downregulation was detected for the matrix metalloproteinases MMP2, MMP7, MMP9, the tissue-inhibitor of metalloproteinase TIMP2, the Integrin receptor subunits ITGA4, ITGA5 and ITGB1, and all receptor protein tyrosine phosphatase β/ζ isoforms. Downregulation of Brevican, Collagen IV, Tenascin-R, MMP2, TIMP2, and ITGA5 was also verified in Etoposide resistant Y79 cells compared to sensitive ones. Protein levels of Tenascin-C and MMP-2 were comparable in both WERI cell lines. Interestingly, Fibronectin displayed an apoptosis-inducing effect on WERI-RB1 cells, whereas an anti-apoptotic influence was observed for Tenascin-C. Conversely, proliferation of WERI-ETOR cells was enhanced on Tenascin-C, while an anti-proliferative effect was observed on Fibronectin. In WERI-ETOR, cluster formation was decreased on the substrates Collagen IV, Fibronectin, and Tenascin-C. Collectively, we noted a different ECM mRNA expression and behavior of Etoposide resistant compared to sensitive RB cells. These findings may indicate a key role of ECM components in chemotherapy resistance formation of RB.

Retinopathy in young retinoblastoma patients receiving a chemotherapy treatment: clinical trials and morphometric analysis

Background: This research is to evaluate patients with retinoblastoma, who receive chemotherapy, with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) to compare the signs of retinopathy.Materials and Methods: A prospective non-randomized trial included 125 eyes of 74 patients at the age of 24 ± 1.6 months with retinoblastoma. All patients underwent an ophthalmoscopic examination and EDI-OCT before therapeutic treatment. The test group consisted of 55 patients, who underwent a course of chemotherapy. Patients were divided into two groups depending on the type of chemotherapy. Group #1 patients received six cycles of systemic intravenous chemotherapy treatment, ophthalmoscopic examination, and EDI-OCT occurred after third cycle and sixth cycle. Group #2 underwent three cycles of IVC chemotherapy treatment, and then local chemotherapy - three cycles of super-selective intra-arterial chemotherapy for exophytic retinoblastoma and 9 procedures of intravitreal (IVT) for endophytic retinoblastoma. Eyes in the control group were affected by eccentric neoplasms but macula and the optic nerve were not damaged.Results: After six cycles of IVC chemotherapy treatment, Group #1 history expanded with atrophy-induced peripapillary nerve fiber layer thinning (33.9%). At three cycle of super-selective intra-arterial chemotherapy, OCT imaging in Group #2 revealed more related symptoms like retinal vascular distention in peritumoral area. After systemic and intravitreal chemotherapy, macular puckers and small hyperreflective dotted foci in the inner retina were tracked. In Group #3 affected by peripheral tumors, the topographic anatomy of the macula was normal prior to therapy.Conclusion: Profound morphometric disturbances that come with combined chemotherapy call for a more careful treatment with methods selected in terms of OCT findings and specific chemotherapy contraindications.

Ginsenoside-Rg5 Inhibits Retinoblastoma Proliferation and Induces Apoptosis through Suppressing BCL2 Expression

BACKGROUND/AIMS

Although the cure rate for retinoblastoma is high, surviving patients are at risk for developing secondary cancers and require life-long follow-up. It is imperative to discover and develop novel therapeutic agents with better efficiency and fewer adverse effects. Ginsenoside-Rg5 is an active derivate from ginseng and exerts anti-cancer activity in breast cancer cells. However, it is still unclear whether ginsenoside-Rg5 has similar anti-cancer functions in retinoblastoma.

METHODS

Retinoblastoma cells were treated with ginsenoside-Rg5, followed by MTT assay analysis of the cell viability, cell number assay and colony formation assay analyses of cell proliferation, and flow cytometric analysis of apoptosis. Gene mRNA levels and protein levels were determined by quantitative real-time PCR and Western blot, respectively.

RESULTS

Ginsenoside-Rg5 inhibited retinoblastoma cell viability in a dose-dependent and time-dependent manner via preventing cell proliferation and inducing cell apoptosis. BCL2 expression was downregulated by ginsenoside-Rg5 treatment via inactivating the AKT signaling pathway. BCL2 overexpression completely eliminated the inhibitory effect of ginsenoside-Rg5 on cancer cell viability.

CONCLUSION

Ginsenoside-Rg5 inhibits cell proliferation and induces apoptosis in retinoblastoma cells by inactivating the AKT signaling pathway, thereby downregulating BCL2 expression.

MicroRNA‑93‑5p promotes the progression of human retinoblastoma by regulating the PTEN/PI3K/AKT signaling pathway

Numerous reports have indicated that microRNA‑93‑5p (miR‑93‑5p) is involved in the development and progression of human cancer, including non‑small cell lung, gastric and breast cancer; however, the role of miR‑93‑5p in retinoblastoma (RB) remains unknown. In the present study, it was reported that miR‑93‑5p expression levels were significantly upregulated in RB tissues compared with in normal tissues by reverse transcription‑quantitative polymerase chain reaction. Furthermore, it was demonstrated via cell counting kit‑8 and Transwell assays that knockdown of miR‑93‑5p significantly suppressed the proliferation, migration and invasion of RB cells, but promoted cellular apoptosis. Regarding the underlying mechanism, the present study reported that phosphatase and tensin homolog (PTEN) was a direct target of miR‑93‑5p in RB cells. Overexpression of miR‑93‑5p significantly inhibited the expression of PTEN; opposing results were observed when PTEN expression was downregulated. Furthermore, the present study revealed that PTEN expression levels were downregulated and were inversely correlated with that of miR‑93‑5p in RB tissues. Additionally, the present study demonstrated that knockdown of PTEN in miR‑93‑5p‑depleted RB cells significantly reversed the effects of miR‑93‑5p on cell proliferation, migration and invasion; miR‑93‑5p knockdown was suggested to promote PTEN expression, consequently inhibiting the activation of phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway. Collectively, the results of the present study demonstrated that miR‑93‑5p may serve a role as an oncogene by modulating the PTEN/PI3K/AKT signaling pathway in RB, indicating that miR‑93‑5p may be a potential therapeutic target for the treatment of RB.

Autologous fat graft in irradiated orbit postenucleation for retinoblastoma

Autologous fat grafting has been extensively and successfully adopted in a number of pathologic conditions in regenerative surgery especially on irradiated fields in order to improve pain symptoms and tissue trophism promoting scar release. In the present study, we report our experience with autologous fat grafting for the treatment of postirradiation fibrosis and pain on three consecutive patients undergoing orbital enucleation for locally advanced retinoblastoma (RB) and subsequent radiotherapy. We selected three consecutive patients who underwent orbital enucleation for locally advanced RB and subsequent local radiotherapy showing severe reduction in orbital volume and eyelid length and retraction due to fibrosis, spontaneous local pain exacerbated after digital pressure with no possibility to place an ocular implant. They underwent autologous fat grafting in the orbital cavity and results were evaluated by clinical examination at 5 and 14 days, and 1, 3, 6 months, and 1 year after surgery. A significant release of scar retraction, reduction of fibrosis and orbital rim contraction together with an important improvement of pain symptoms was observed in all patients. The local changes observed enabled an ease placement of an ocular prosthetic implant (implant). No local or systemic complication occurred. Fat grafting is a promising treatment for patients showing radiotherapy related complication in the orbital area and it should be adopted by all oculoplastic surgeon in order to improve pain syndrome creating the ideal local conditions for the placement of an ocular prosthetic implant.

LncRNA HOTAIR/miR-613/c-met axis modulated epithelial-mesenchymal transition of retinoblastoma cells

Since lncRNAs could modulate neoplastic development by modulating downstream miRNAs and genes, this study was carried out to figure out the synthetic contribution of HOTAIR, miR-613 and c-met to viability, apoptosis and proliferation of retinoblastoma cells. Totally 276 retinoblastoma tissues and tumour-adjacent tissues were collected, and human retinoblastoma cell lines (ie, Y79, HXO-Rb44, SO-Rb50 and WERI-RB1) were also gathered. Moreover, transfections of pcDNA3.1-HOTAIR, si-HOTAIR, miR-613 mimic, miR-613 inhibitor, pcDNA3.1/c-met were performed to evaluate the influence of HOTAIR, miR-613 and c-met on viability, apoptosis and epithelial-mesenchymal transition (EMT) of retinoblastoma cells. Dual-luciferase reporter gene assay was also arranged to confirm the targeted relationship between HOTAIR and miR-613, as well as between miR-613 and c-met. Consequently, up-regulated HOTAIR and down-regulated miR-613 expressions displayed associations with poor survival status of retinoblastoma patients (P < 0.05). Besides, inhibited HOTAIR and promoted miR-613 elevated E-cadherin expression, yet decreased Snail and Vimentin expressions (P < 0.05). Simultaneously, cell proliferation and cell viability were also less-motivated (P < 0.05). Nonetheless, c-met prohibited the functioning of miR-613, resulting in promoted cell proliferation and viability, along with inhibited cell apoptosis (P < 0.05). Finally, HOTAIR was verified to directly target miR-613, and c-met was the direct target gene of miR-613 (P < 0.05). In conclusion, the role of lncRNA HOTAIR/miR-613/c-met signalling axis in modulating retinoblastoma cells' viability, apoptosis and expressions of EMT-specific proteins might provide evidences for developing appropriate diagnostic and treatment strategies for retinoblastoma.

Quality of life in children with retinoblastoma after enucleation in China

OBJECTIVE

To study the quality of life of Chinese pediatric patients with retinoblastoma (RB) after enucleation and the influencing factors.

METHODS

A questionnaire survey was performed on 71 cases of pediatric patients with RB after enucleation and 80 cases of healthy children, using the Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL™ 4.0).

RESULTS

The social dimension scores, school dimension scores, and total scores for the PedsQL™ 4.0 among the pediatric patients with RB were statistically significantly lower than those of healthy children. The influencing factors were unilateral/bilateral affected eyes, diagnosis age, and ocular prosthesis satisfaction.

CONCLUSION

Early discovery, timely treatment, increased eye salvage rate, and cosmetic effects of ocular prosthesis were key factors for increasing the quality of life of pediatric patients with RB. Attention should be paid to the health, social, and school development of pediatric patients with RB.

Immunohistochemical assay for neuron-specific enolase, synaptophysin, and RB-associated protein as a diagnostic aid in advanced retinoblastomas

Purpose

We evaluated the expression of the neural markers, neuron-specific enolase, and synaptophysin, as a tool to confirm the diagnosis of retinoblastoma (RB) in undifferentiated and advanced tumors. Additionally, we determined whether the extent of RB-associated protein (pRb) expression is helpful in assessing the prognosis in RB patients.

Methods

Conventional whole tissue section and tissue microarray immunohistochemistry for neuron-specific enolase, synaptophysin, and pRb were carried out in a series of 22 RBs.

Results

Neuron-specific enolase and synaptophysin were expressed in 75%–100% of the tumor cells, and the staining intensity was strong. Two RBs expressed pRb in 75%–100% of the tumor cells, also with strong staining intensity. Concordance between the immunohistochemical outcomes for whole tissue staining and tissue microarray staining was 76.2% for neuron-specific enolase, 85.7% for synaptophysin, and 80.0% for pRb.

Conclusion

Neuron-specific enolase and synaptophysin have the potential to be useful markers for the diagnosis of RBs. Extensive and strong pRb staining is not associated with less aggressive tumor behavior according to the pathologic classification of RBs.

Downregulation of NIMA-related kinase-7 inhibits cell proliferation by inducing cell cycle arrest in human retinoblastoma cells

NIMA-related kinase-7 (Nek7) is a centrosomal kinase involved in various types of cancer, including gallbladder cancer and hepatocellular carcinoma. However, the biological function and the potential underlying mechanism of Nek7 in retinoblastoma remain largely unknown. Therefore, the present study investigated the effects of Nek7 in retinoblastoma cells. The expression of Nek7 was initially determined and observed to be commonly upregulated in retinoblastoma cell lines (Y79, SO-RB50 and WERI-RB1) as compared with that in normal retinal pigment epithelium cells. Next, the endogenous expression of Nek7 was efficiently knocked down in Y79 and SO-RB50 cells using a lentivirus-mediated RNA interference approach, as confirmed by reverse transcription-quantitative polymerase chain reaction and western blot analysis. Loss-of-function assays, including MTT, colony formation and flow cytometry, indicated that knockdown of Nek7 significantly inhibited cell growth, impaired the colony formation ability and induced cell cycle arrest at G0/G1 phase. Furthermore, mechanistic studies demonstrated that silencing of Nek7 resulted in reduced cyclin-dependent kinase 2, cyclin D1 and cyclin E levels in vitro. In conclusion, the present study highlights the crucial role of Nek7 in promoting retinoblastoma cell proliferation, and Nek7-silencing may serve as a novel therapeutic target for retinoblastoma.

Expression of multidrug resistance proteins in retinoblastoma

AIM

To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance.

METHODS

Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC) were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin) were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells.

RESULTS

Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp) was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1) expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp) was observed in the drug resistant Y79 cells as well as in PCNC.

CONCLUSION

Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

A 20-Year Retrospective Review of Retinoblastoma at Two Tertiary Academic Hospitals in Johannesburg, South Africa

Aim

This paper presents a 20-year review of retinoblastoma in Johannesburg, South Africa, aiming to better characterize the disease in this sub-Saharan setting.

Methods

The study represents a retrospective case series of retinoblastoma patients presenting to Charlotte Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath Academic Hospital between January 1, 1992, and December 31, 2011.

Results

The total number of cases identified was 282, with 245 meeting the study inclusion criteria. Retinoblastoma comprised 6.9% of the total pediatric oncology presentations; 65.3% were unilateral, 34.3% bilateral, and 0.4% trilateral. The overall male-to-female ratio was 1.08. The mean age at presentation overall was 32.6 months (median 28.0), in the unilateral group 39.4 months (median 33.0), and in the bilateral group 19.7 months (median 17.0). The mean delay to presentation overall was 7.0 months (median 4.0). The most frequent presenting symptoms were leukocoria (37.1%) and proptosis (34.7%). The distribution of disease stages at presentation (International Retinoblastoma Staging System) was 1.6% stage 0, 24.1% stage I, 27.8% stage II, 16.3% stage III, and 25.3% stage IV. 26.5% defaulted care. The 5-year Kaplan-Meier survival estimate was 57.7% overall.

Conclusion

This study shows that delayed presentation and refusal of therapy remains a significant barrier to effective treatment in this African setting.

Recent advances and challenges in the management of retinoblastoma

The treatment of retinoblastoma (Rb) has improved significantly in recent times. Worldwide, there is an increasing trend to use conservative treatment modalities that aim to preserve the globe as well as vision with minimum morbidity. Recently, the use of targeted delivery of chemotherapy to the eye in the form of selective intra-arterial and intravitreal chemotherapy has shown promising results. Radiotherapy is beneficial in selected cases, either in the form of plaque brachytherapy or as external beam radiotherapy. Orbital disease carries a poor prognosis for survival. However, a multimodal treatment protocol has improved survival in children with extraocular disease. Nevertheless, challenges remain, especially for the developing world. This review aims to highlight recent advances in the management of Rb that have contributed towards improving treatment outcomes and also discuss the challenges ahead, with special reference to the Indian scenario.

Giant retinal tear after intra-arterial chemotherapy for advanced unilateral retinoblastoma

BACKGROUND

Retinoblastoma is considered the most common intraocular malignancy in childhood, comprising 4% of all pediatric cancers. Management of retinoblastoma has evolved over the past two decades and intra-ophthalmic artery chemotherapy has emerged as a new modality of globe-conserving treatment with excellent results. This treatment achieves effective tumor reduction by delivering localized chemotherapy, decreases enucleation rate, and minimizes systemic and local side effects.

CASE PRESENTATION

We report the case of an 8-year-old girl with a late presentation of an advanced unilateral retinoblastoma associated to diffuse exudative retinal detachment in the right eye, classified as group E by the International Classification of Retinoblastoma. The initial therapeutic proposal for the patient was five sessions of intra-ophthalmic artery chemotherapy (IAC) associated to large spot diode laser therapy. After undergoing four sessions of IAC, the fundus exam revealed a giant retinal tear associated to a total retinal detachment in the affected eye. The IAC treatment was concluded and enucleation was considered the best treatment option at that moment, since IAC was unable to control the tumor's activity and the patient's eye presented with a complex rhegmatogenous retinal detachment (RRD). However, family left for a second opinion and never returned.

CONCLUSIONS

The usage of IAC for retinoblastoma management may lead to important local complications. Despite rare, RRD secondary to IAC may occur. We postulate that the giant tear observed in this case was caused by the rapid tumor necrosis using this route of treatment.

Quercetin inhibits angiogenesis-mediated human retinoblastoma growth by targeting vascular endothelial growth factor receptor

Retinoblastoma (RB) is the most common malignant intraocular cancer in teenagers, occurrence of which depends on the mutation of multiple genes. Among all the signaling pathways involved in the oncogenesis of RB, the process of angiogenesis has been demonstrated to be associated with the local invasive growth and metastasis of this cancer type. Quercetin (Que) is a typical flavonoid and has been reported to inhibit angiogenesis in various types of tumors. In the present study, the effect of Que on RB cells and angiogenesis of RB was evaluated. The human RB Y79 cell line was subjected to treatment with Que of various concentrations. Viability, invasion and migration ability and apoptosis of Y79 cells were subsequently measured to assess the effect of Que on RB cells. In addition, the expression of vascular endothelial growth factor receptor (VEGFR) was also quantified. It was revealed that Que inhibited RB cell growth and invasion in vitro in a dose-dependent manner, with 100 µM Que exhibiting the strongest inhibitory effect. In addition, Que downregulated the expression of VEGFR, which was an indicator of the blockade of angiogenesis in RB by targeting VEGF. The effect of Que on angiogenesis was also observed to be dose-dependent. The results of the present study indicated that Que may be a potential anti-RB therapy due to its anti-angiogenesis effect.

Identification of differentially expressed proteins in retinoblastoma tumors using mass spectrometry-based comparative proteomic approach

In India, retinoblastoma is among the top five childhood cancers. Children mostly present with extraocular extension and high risk features that results in unsatisfactory treatment and low survival rate. In addition, lack of potential therapeutic and prognostic targets is another challenge in the management of retinoblastoma. We studied comparative proteome of retinoblastoma patients (HPV positive and negative (n=4 each) and controls (n=4), in order to identify potential retinoblastoma-specific protein targets. 2D-DIGE coupled MALDI-TOF/TOF mass spectrometry identified 39 unique proteins. Highly deregulated proteins were GFAP,RBP3,APOA1,CRYAA,CRABP1,SAG and TF. Gene ontology (Panther 7.0) revealed majority of proteins to be associated with metabolic processes (26%) and catalytic activity (38%). 8 proteins were significantly upregulated in HPV positive vis-a-vis HPV negative cases. Patient group exhibited 12 upregulated and 18 downregulated proteins compared to controls. Pathway and network analysis (IPA software) revealed CTNNB1 as most significantly regulated signalling pathway in HPV positive than HPV negative retinoblastoma. The trends in transcriptional change of 9 genes were consistent with those at proteomic level. The Western blot analysis confirmed the expression pattern of RBP3,GFAP and CRABP1. We suggest GFAP,RBP3,CRABP1,CRYAAA,APOA1 and SAG as prospective targets that could further be explored as potential candidates in therapy and may further assist in studying the disease mechanism.

SIGNIFICANCE

In this study we evaluated tumor tissue specimens from retinoblastoma patients and identified 39 differentially regulated proteins compared to healthy retina. From these, we propose RBP3, CRABP1, GFAP, CRYAA, APOA1 and SAG as promising proteomic signatures that could further be explored as efficient prognostic and therapeutic targets in retinoblastoma. The present study is not only a contribution to the ongoing endeavour for the discovery of proteomic signatures in retinoblastoma, but, may also act as a starting point for future studies aimed at uncovering novel targets for further therapeutic interventions and improving patient outcomes.

Retinoblastoma: might photodynamic therapy be an option?

Retinoblastoma is a tumor that mainly affects children under 5 years, all over the world. The origin of these tumors is related with mutations in the RB1 gene, which may result from genetic alterations in cells of the germ line or in retinal somatic cells. In developing countries, the number of retinoblastoma-related deaths is higher due to less access to treatment, unlike what happens in developed countries where survival rates are higher. However, treatments such as chemotherapy and radiotherapy, although quite effective in treating this type of cancer, do not avoid high indices of mortality due to secondary malignances which are quite frequent in these patients. Additionally, treatments such as cryotherapy, thermotherapy, thermochemotherapy, or brachytherapy represent other options for retinoblastoma. When all these approaches fail, enucleation is the last option. Photodynamic therapy might be considered as an alternative, particularly because of its non-mutagenic character. Photodynamic therapy is a treatment modality based on the administration of photosensitizing molecules that only upon irradiation of the tumor with a light source of appropriate wavelength are activated, triggering its antitumor action. This activity may be not only due to direct damage to tumor cells but also due to damage caused to the blood vessels responsible for the vascular supply of the tumor. Over the past decades, several in vitro and in vivo studies were conducted to assess the effectiveness of photodynamic therapy in the treatment of retinoblastoma, and very promising results were achieved.

MicroRNA-125b promotes tumor growth and suppresses apoptosis by targeting DRAM2 in retinoblastoma

PurposeIt is known that microRNAs (miRNAs) are a class of small, noncoding RNAs that act as key regulators in various physiological and pathological processes. However, the regulatory mechanisms involving miRNAs in retinoblastoma (RB) remain largely unknown. The miRNA miR-125b is dysregulated in various human cancers such as breast cancer, human hepatocellular carcinoma, ovarian cancer, and colorectal cancer. However, the significance of miR-125b in RB has not been sufficiently investigated. Our objective was to explore the role of the miR-125b in RB.MethodsIn this study, we measured miR-125b levels using real-time polymerase chain reaction in human RB cell lines, including HXO-Rb44, Y79, SO-RB50, and the normal human retinal pigment epithelial cell line ARPE-19; a total of 38 pairs of primary RB tissues and adjacent noncancerous tissues were also measured. In addition, overexpression of miR-125b in RB cell lines was performed to determine the role of miR-125b in RB.ResultsWe found that miR-125b is significantly upregulated in RB, and closely associated with tumor cell proliferation and apoptosis. In addition, overexpression of miR-125b apparently promotes RB cell proliferation and migration in vitro. Gain-of-function in vitro experiments further showed that the miR-125b mimic significantly suppressed RB cell apoptosis. A subsequent dual-luciferase reporter assay identified the suppressor gene DRAM2 as direct target of miR-125b.ConclusionsOur data collectively demonstrate that miR-125b is a suppressor gene miRNA that can promote RB cell proliferation and migration by downregulating the suppressor gene DRAM2, indicating that miR-125b may represent a new potential diagnostic and therapeutic target for RB treatment.

Proteomic analysis of differentially expressed proteins in vitreous humor of patients with retinoblastoma using iTRAQ-coupled ESI-MS/MS approach

There is close proximity of vitreous humor with the tumor bulk in eyes with retinoblastoma. This renders vitreous humor a promising source to evaluate disease-specific protein targets in retinoblastoma. We studied the differential proteome of vitreous fluid in retinoblastoma tumors (n = 4) as compared to controls (n = 4). The vitreous humor was depleted off the high abundant fraction using MARS-6 affinity column. Subsequently, the tryptic peptides were derivatised with iTRAQ labels. The labelled peptides were pooled and subjected to fractionation using bRPLC. This was followed by protein identification and quantification using electrospray ionisation mass spectrometry (ESI-MS/MS) approach. The identified proteins were subjected to bioinformatics analysis utilizing PANTHER 7.0 and IPA software. Four hundred and thirty-one non-redundant (362 upregulated and 69 downregulated) proteins (≥2 unique peptides, ± 1.5 folds, p < 0.05) were identified. The majority of the proteins were cytoplasmic (40 %), majorly involved in catalytic (32.7 %) and binding activities (26.3 %). Highly deregulated proteins included MMP2, TNC, CD44, SUZ12 and CRABP1. The protein expression of GFAP, CRABP1, MMP2 and TNC was validated by western blotting. Pathway and network analyses revealed p38MAPK and Akt signalling to be the most significantly regulated pathways in retinoblastoma. This is the first report of differential vitreous proteome of retinoblastoma and highlights novel protein targets, such as MMP2, TNC and CRABP1. Further investigations into unravelling the biological role of the proteins and their prospects of being utilised as potential candidates in therapeutics are warranted.

Targeting Survivin Enhances Chemosensitivity in Retinoblastoma Cells and Orthotopic Tumors

Treatments for retinoblastoma (Rb) vary depending on the size and location of the intraocular lesions and include chemotherapy and radiation therapy. We examined whether agents used to treat Rb induce a pro-survival phenotype associated with increased expression of survivin, a member of the inhibitor of apoptosis family of proteins. We document that exposure to carboplatin, topotecan or radiation resulted in elevated expression of survivin in two human Rb cell lines but not in normal retinal pigmented epithelial (RPE) cells. Cellular levels of survivin were attenuated in Rb cells exposed to an imidazolium-based survivin suppressant, Sepantronium bromide (YM155). Protein expression patterns of survivin in RPE cells were not altered following treatment protocols involving exposure to YM155. Including YM155 with chemotherapy or radiation increased levels of apoptosis in Rb cells but not in RPE cells. Intraocular luciferase expressing Rb tumors were generated from the Rb cell lines and used to evaluate the effects of carboplatin and YM155 on in-vivo survivin expression and tumor growth. Carboplatin induced expression of survivin while carboplatin combined with YM155 reduced survivin expression in tumor bearing eyes. The combination protocol was also most effective in reducing the rate of tumor regrowth. These results indicate that targeted inhibition of the anti-apoptotic protein survivin provides a therapeutic advantage for Rb cells and tumors treated with chemotherapy.

Long-term audiologic follow-up of carboplatin-treated children with retinoblastoma

BACKGROUND

Children treated for retinoblastoma with carboplatin have an increased risk for ototoxicity. Impaired hearing may have major consequences for these children, because they often suffer from reduced vision. Previous studies have shown limited information on the incidence and severity of carboplatin-induced ototoxicity and the used audiologic methods. The frequency of audiological testing is often limited and the audiologic follow-up time is relatively short.

OBJECTIVE

The aim of this study was to determine the long-term effects of carboplatin ototoxicity in children with retinoblastoma.

MATERIALS AND METHODS

In this retrospective non-randomized single center cohort study, we reviewed audiologic results of 25 patients. Experienced audiologists analyzed the pure-tone audiograms.

RESULTS

All patients had normal hearing prior to therapy and had a mean age of 11 months at first carboplatin administration. The mean audiologic follow-up was 12.0 years with a median of 11.6 (IQR 4.8) years. Three patients were excluded: two passed away and one could not participate in the audiologic tests. One of the 22 included patients developed sustained low-grade bilateral high-frequency hearing loss between 2 and 7 years after the last carboplatin dose. In one patient it was not possible to make a reliable conclusion due to a conductive hearing loss component. Twenty patients had normal hearing.

CONCLUSIONS

We observed no clear effect between carboplatin administration in young children and clinical significant ototoxicity in the long term. One child showed low-grade bilateral high-frequency hearing loss.

Short stature in retinoblastoma survivors: a cross-sectional study of 138 patients

PURPOSE

Short stature has been reported in pediatric cancer survivors. Data on retinoblastoma survivors are limited. We conducted a cross-sectional study to assess the height in retinoblastoma survivors.

METHOD

The recorded height was compared with median height for age and sex as per the Indian Academy of Pediatrics. Z-score less than -2 was considered short statured.

RESULT

Thirty percent of the survivors were short statured. The mean height was shorter than the mean 50th percentile height (119.7 ± 14.8 vs 128.7 ± 15 cm, p < 0.001). Previous chemotherapy showed a trend toward association (p = 0.09).

CONCLUSION

Short stature affects a significant number of retinoblastoma survivors.

Quality of Life Assessment in Retinoblastoma: A Cross-Sectional Study of 122 Survivors from India

BACKGROUND

With current modalities, cure rates of retinoblastoma are high and hence the number of survivors is increasing. However, data on quality of life (QOL) are minimal.

PROCEDURE

We analyzed QOL in 122 retinoblastoma survivors using the PedsQL(TM) 4.0 generic core scale. The self-reported questionnaire was filled by children of more than 5 years of age who had completed treatment for more than 12 months. The questionnaire consists of 23 questions on physical, social, emotional, and school domains on a scale from 0 to 4. This was converted to a scale from 0 to 100, where higher values represented better QOL. The QOL was compared with 50 siblings. Factors predicting the QOL were assessed.

RESULTS

The median age of retinoblastoma survivors was 98 months (range 60-247) and 68% were males. Overall QOL was significantly poorer in retinoblastoma survivors as compared with the controls. The emotional health domain of QOL was significantly affected. Difficulties in maintaining friendships and competing were reported in the social health domain. The school health domain showed significantly higher absenteeism. However, the physical health domain, including household work, exercise, and self-care, was similar in both the groups. Lower age at diagnosis (≤ 18 months) predicted better QOL (P = 0.05), whereas age at assessment, sex, IRSS stage, and previous surgery and radiotherapy were not predictive of poor QOL.

CONCLUSIONS

We found a significantly poorer QOL in retinoblastoma survivors with the psychosocial health domain being more affected than the physical domain. Age less than 18 months at diagnosis predicted better QOL.

Long-term visual outcomes in intraocular retinoblastoma with eye preservation

PURPOSE

Inconsistent data exist on long-term visual outcomes in survivors of retinoblastoma. No studies have been reported on role of ocular coherence tomography (OCT) in predicting visual acuity. We assessed visual acuity in patients with retinoblastoma treated at our center in whom affected eyes were preserved.

METHODS

Patients who had completed a 2-year follow-up and were more than 5 years of age at assessment were included. Clinical data were obtained from database and factors predicting visual acuity were analyzed. OCT was performed in these patients to assess central macular thickness (CMT).

RESULTS

Visual outcomes were assessed in 45 eyes of 43 patients, of which 38 (88 %) had bilateral retinoblastoma. The median age at diagnosis was 12 months. Sixty percent (27/45) had International classification of retinoblastoma group C or D disease with 40 % eyes showing macular lesions. The far visual acuity was better than 6/12 in 53 % (24/45), 6/12 to 6/60 in 40 % (18/45) and 6/60 in 7 % (6/60). Macular location and International classification of retinoblastoma predicted poor vision (p = 0.06 and 0.07, respectively). CMT was less than 200 μm in 3 of 36 eyes (8 %) and 1 eye showed epiretinal membrane. Radiotherapy was associated with foveal thinning (p = 0.003). Two of 3 eyes with foveal thinning had a vision of 6/60.

CONCLUSIONS

Good visual outcomes were observed in half of retinoblastoma patients treated with eye preservation. Macular location and International classification of retinoblastoma group C and D predicted poor visual acuity, while previous radiotherapy predicted foveal thinning, which was associated with poor visual acuity.

Breaking down barriers to communicating complex retinoblastoma information: can graphics be the solution?

OBJECTIVE

To investigate the impact of a graphical timeline summarizing bilateral retinoblastoma disease and treatment outcomes on parents' understanding of complex medical information.

DESIGN

Cross-sectional survey.

PARTICIPANTS

Parents of children with retinoblastoma who were being actively managed at The Hospital for Sick Children were recruited. Forty-five parents from 42 families participated.

METHODS

After a standardized presentation on retinoblastoma and visual tool named Disease-Specific electronic Patient Illustrated Clinical Timeline (DePICT), parents completed a 19-item questionnaire designed to assess their understanding of treatment choices for 2 eyes in bilateral retinoblastoma as communicated using DePICT. SPSS was used to perform statistical analysis.

RESULTS

Forty-five parents from 42 families participated (65% female). Median age of participants was 34 years. Median level of participant education was completion of college/trade school. The median level of annual income was $40,000 to $70,000 CDN. Median time since diagnosis of retinoblastoma in their child was 13.5 months. Twenty-three (51%) participants were parents of children with unilateral retinoblastoma, and 22 (49%) were parents of children with bilateral retinoblastoma. Median number of correct answers was 15 of 19, and mean score was 77%. Normal distribution of scores was noted. English as a first language was significantly associated with score (p = 0.01). No significant association was observed between other variables and score in all analyses.

CONCLUSIONS

This study builds on the validation of DePICT by demonstrating that parents can achieve good comprehension even when considering choices for treatment for 2 eyes with bilateral retinoblastoma. Clinical application of this tool can enhance the consent process.

In search of underlying mechanisms and potential drugs of melphalan-induced vascular toxicity through retinal endothelial cells using bioinformatics approach

We aimed to explore molecular mechanism and drug candidates of vascular toxicities associated with melphalan after treating human retinal endothelial cells (RECs). GSE34381 microarray data was firstly downloaded and used to identify the differentially expressed genes (DEGs) in human REC treated with melphalan vs. untreated cells by limma package in R language. The transcription network was constructed based on TRANSFAC database and the top five transcription factors (TFs) were select with a measure of regulatory impact factor, followed by the construction of function modules. Gene ontology enrichment analyses were performed to explore the enriched functions. Connectivity Map analysis was conducted to predict the potential drugs overcoming the melphalan's actions on REC. Totally, 75 DEGs were identified, including 70 up-regulated and five down-regulated genes. Transcription network with 1311 nodes and 1875 edges was constructed and the top five TFs were CREM, MYC, FLI1, NF-κB1, and JUN. Functional modules indicated that NF-κB1 and MYC were the important nodes. The upregulated genes as well as the genes involved in the modules mainly participated in biological process of immune response, cell proliferation, and cell motion. Five small molecules were predicted to be potential drug candidates, including doxorubicin, fipexide, daunorubicin, tiabendazole, and GW-8510. Based on these results, we speculate that NF-κB1 and MYC might involve in the molecular mechanism of vascular toxicity induced by melphalan through regulating their target genes. Five small molecules might be drug candidates to overcome the melphalan-induced vascular toxicity via targeting to MYC and JUN.

Diffuse anterior retinoblastoma: current concepts

Diffuse anterior retinoblastoma is a rare variant of retinoblastoma seeding in the area of the vitreous base and anterior chamber. Patients with diffuse anterior retinoblastoma are older than those with the classical types, with the mean age being 6.1 years. The original cells of diffuse anterior retinoblastoma are supposed to be cone precursor. Patients most commonly present with pseudouveitis, pseudohypopyon, and increased intraocular pressure. The retina under fundus examination is likely to be normal, and the clinical features mimic the inflammation progress, which can often lead to misdiagnosis. The published diffuse anterior retinoblastoma cases were diagnosed after fine-needle aspiration biopsy running the potential risk of inducing metastasis. The most common treatment for diffuse anterior retinoblastoma is enucleation followed by systematic chemotherapy according to the patient’s presentation and clinical course. This review summarizes the recent advances in etiology (including tumorigenesis and cell origin), pathology, diagnosis, differential diagnosis, and new treatment. The challenges of early diagnosis and prospects are also discussed.