Current therapy and recent advances in the management of retinoblastoma

Epidemiology, Diagnosis and Genetics of Retinoblastoma: ICMR Consensus Guidelines

Retinoblastoma (RB) is the most common intraocular tumor in childhood. It is mainly caused by mutations in both alleles of the RB1 tumor suppressor gene that is found on chromosome 13 and regulates the cell cycle. Approximately 8000 children are diagnosed with RB globally each year, with an estimated 1500 cases occurring in India. The survival rate of RB has improved to more than 90% in the developed world. Leukocoria and proptosis are the most common presenting features of RB in Asian Indian populations. Most cases of RB are diagnosed by fundus examination followed by ultrasound. The International Classification of Retinoblastoma is the most used scheme for the staging and classification of intraocular RB in India. Prenatal testing and preimplantation genetic testing for RB may be beneficial in high-risk families. Histopathologic risk factors such as massive choroidal invasion and post-laminar optic nerve help in predicting the occurrence of metastasis in children with RB, while presence of microscopic residual disease requires aggressive adjuvant treatment in eyes enucleated for group E RB. The review provides a consensus document on diagnosis and genetics of RB in India.

Management of Intraocular Retinoblastoma: ICMR Consensus Guidelines

Retinoblastoma (RB) is the most common childhood intraocular malignancy. Delayed presentation due to a lack of awareness and advanced intraocular tumors are a common scenario in low-middle income countries (LMICs). Remarkable treatment advances have been made in the past few decades allowing globe salvage in advanced intraocular RB (IORB) including systemic chemotherapy with focal consolidation and targeted treatments like intraarterial chemotherapy and intravitreal chemotherapy. However, a lack of availability and affordability limits the use of such advances in LMICs. External beam radiotherapy, despite risk of second cancers in RB with germline mutations, still remains useful for recalcitrant RB not responding to any other treatment. When choosing conservative treatment for advanced IORB, the cost and long duration of treatment, morbidity from multiple evaluation under anesthesias (EUAs), side effects of treatment and risk of treatment failure need to be taken into account and discussed with the parents. In this article, the authors discuss the ICMR consensus guidelines on the management of IORB.

Assessing the Metabolic Variations of Invasive and Noninvasive Unilateral Retinoblastoma Patients

Retinoblastoma (Rb) is a pediatric eye cancer which if diagnosed at later stages can lead to Rb invasion into the choroid, optic nerve, sclera, or beyond, with the potential of undergoing metastasis. Cancer cells, including Rb cells, reprogram their metabolic circuits for their own survival and progression, which provides a great opportunity to monitor the extent of Rb progression based on metabolic differences. Henceforth, the present study aims to map the metabolic variations in patients with invasive (primarily enucleated eyes with high-risk histopathological features) and noninvasive (eyes salvaged with treatment) unilateral retinoblastoma (Rb) using nuclear magnetic resonance (NMR) based serum metabolomics. Quantification of differential metabolites in the serum obtained from 9 patients with invasive and 4 with noninvasive unilateral Rb along with 6 controls (no retinal pathology) was carried out using 1H NMR spectroscopy. A total of 71 metabolites, such as organic acids, amino acids, carbohydrates, and others, were identified in the serum obtained from 9 patients with invasive and 4 with noninvasive unilateral Rb. Partial least-squares discriminant analysis (PLS-DA) models depicted distinct grouping of invasive and noninvasive Rb patients and controls. Differential metabolic fingerprints were observed for invasive and noninvasive Rb patients based on their biostatistical analyses with respect to controls. Remarkable perturbation was observed among various metabolites such as 4-aminobutyrate, 2-phosphoglycerate, O-phosphocholine, proline, Sn-glycero-3-phosphocholine (Sn-GPC), and O-phosphoethanolamine in noninvasive and invasive Rb patients with most of the effects being heightened in the latter group. Metabolic changes unique to invasive and noninvasive Rb patients were also observed. Multivariate receiver operating characteristics (ROC) analysis unveiled the highest accuracy and potency of ROC models 2 and 5 to distinguish the noninvasive and invasive Rb from controls, respectively. Metabolites identified in the serum of patients with invasive and noninvasive Rb may aid in advancing our knowledge about Rb tumor biology. Differential aberrant metabolic variations in patients with invasive Rb compared to those with noninvasive Rb may guide the decision of enucleation versus globe salvage.

Retinoblastoma: An update on genetic origin, classification, conventional to next-generation treatment strategies

The most prevalent paediatric vision-threatening medical condition, retinoblastoma (RB), has been a global concern for a long time. Several conventional therapies, such as systemic chemotherapy and focal therapy, have been used for curative purposes; however, the search for tumour eradication with the least impact on surrounding tissues is still ongoing. This review focuses on the genetic origin, classification, conventional treatment modalities, and their combination with nano-scale delivery systems for active tumour targeting. In addition, the review also delves into ongoing clinical trials and patents, as well as emerging therapies such as gene therapy and immunotherapy for the treatment of RB. Understanding the role of genetics in the development of RB has refined its treatment strategy according to the genetic type. New approaches such as nanostructured drug delivery systems, galenic preparations, nutlin-3a, histone deacetylase inhibitors, N-MYC inhibitors, pentoxifylline, immunotherapy, gene therapy, etc. discussed in this review, have the potential to circumvent the limitations of conventional therapies and improve treatment outcomes for RB. In summary, this review highlights the importance and need for novel approaches as alternative therapies that would ultimately displace the shortcomings associated with conventional therapies and reduce the enucleation rate, thereby preserving global vision in the affected paediatric population.

Advancements in Retinoblastoma Treatment: Unraveling the Potential of Intravitreal Chemotherapy

Retinoblastoma necessitates urgent attention due to its potential fatality if untreated. Multiple treatment options are available and should be employed according to size, location, and the extent of dissemination. This review emphasizes the need for increased awareness, advanced diagnostic tools, and innovative treatment approaches, especially intravitreal chemotherapy (IVitC) to address the diverse manifestations and aggressive nature of retinoblastoma. Timely diagnosis and commitment to treatment are pivotal, as delays and reluctance to undergo enucleation contribute to unfavorable outcomes. The evolving treatment landscape, spanning from traditional interventions to modern targeted therapies such as intravitreal melphalan, holds promise for improved outcomes. While the intravitreal approach presents challenges, ongoing research aims to establish its definitive role in retinoblastoma treatment. In the treatment of retinoblastoma, IVitC raises considerations about side effects. The risk of tumor spread beyond the eye is rare, emphasising the potential of IVitC in carefully selected cases. Intravitreal injections exhibit fewer local adverse effects compared to intra-arterial chemotherapy, with careful measures reducing significant ocular complications. The evaluation of ocular toxicity, particularly with melphalan, underscores the importance of a nuanced approach to achieve the right balance between therapeutic efficacy and ocular safety. This comprehensive analysis of studies on IVitC and its ocular and systemic complications provides valuable insights for enhanced patient care. The review concludes with a focus on balancing safety and efficacy in local chemotherapeutic drugs, highlighting the need for thoughtful measures and continued research to optimise treatment modalities globally.

In-vitro Cytotoxicity Investigations for Phytoconstituents of Saudi Medicinal Plants With Putative Ocular Effects

BACKGROUND

Metastatic secondary ocular tumors spread from systemic malignancies, including breast cancer. This study aimed to evaluate the cytotoxicity of extracts from 5 medicinal plants native to Saudi Arabia.

METHODS

For preliminary activity screening, cytotoxicity using the MTT assay and selectivity index determinations were made for medicinal plant extracts against various cancer cell-lines. The most promising extract was subjected to GC-MS analysis to determine the phytochemical composition. Clonogenic assays were performed using the most promising extract to confirm the initial results. Finally, western blot analysis was used to determine the modulation in expression of survivin and P27 suppressor genes in the human breast adenocarcinoma (MCF7) cell-line to understand the potential mechanistic properties of the active plant extract.

RESULTS

The 5 plant extracts showed various cytotoxic activity levels using IC50. The most active extract was found to be the leaves of Capparis spinosa L. (BEP-07 extract) against the MCF7 breast cancer cell-line (IC50 = 3.61 ± 0.99 μg/ml) and selectivity index of 1.17 compared to the normal human fetal lung fibroblast (MRC5) cells. BEP-07 extract showed a dose dependent clonogenic effect against the MCF7 colonies which was comparable with the effect of doxorubicin. BEP-07 extract caused a significant decrease of survivin and increase in P27 expression compared to control GAPDH at its highest dose (14 µg/ml). The GC-MS chromatogram of Capparis spinosa L. (BEP-07 extract) revealed the existence of 145 compounds, belonging to the diverse classes of phytoconstituents. Fatty acids and their derivatives represent 15.4%, whilst octadecanoic acid, 2,3-dihydroxypropyl ester was the principal component (7.9%) detected.

CONCLUSION

Leaves of Capparis spinosa L. (BEP-07 extract) exhibited a significant cytotoxic effect particularly against breast cancer cells. It exhibited this effect through survivin inhibition and via P27 upregulation. The detected phytoconstituents in the plant extract might be involved in tested cytotoxic activity, while further investigations are required to complete the drug candidate profile.

Survival trends for patients with retinoblastoma between 2000 and 2018: What has changed?

INTRODUCTION

Retinoblastoma (RB) is the most common primary intraocular cancer of childhood. Over the last few decades, a variety of techniques and treatment modalities emerged that improved the survival and ocular salvage rate of patients with RB. We investigated the relative survival trends of patients with RB from 2000 to 2018 by using the Surveillance, Epidemiology, and End Results (SEER) database.

DESIGN

Retrospective database review.

METHODS

We extracted data from SEER 18 from 2000 to 2018. All patients with clinically diagnosed RB during the study period were included. We utilized SEER*Stat 8.3.9 and JPSurv software to estimate relative 5- and 10-year survival rates and trends and generated descriptive analyses with IBM SPSS.

MAIN OUTCOME MEASURES

Patient survival rates at 5- and 10-year after RB diagnosis.

RESULTS

RB was diagnosed in 1479 patients within the SEER 18 Program during our study period. The cohort comprised 776 (52.5%) males, 615 (41.6%) non-Hispanic whites, 487(32.9%) Hispanics, 1030 (69.6%) patients with unilateral disease, and 1087 (73.5%) patients with localized disease. Relative survival trends at 5- and 10-year significantly declined over the study periods (-0.42%, and -0.50% annually, respectively) but the decline was not significant in unilateral and bilateral RB cases separately.

CONCLUSIONS

Five- and ten-year relative survival trends declined from 2000 to 2018 and were significantly decreasing. Further studies that include more patients are needed to identify the factors contributing to reduced survival of patients with RB over time.

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.

Dopachrome tautomerase is a retinoblastoma-specific gene, and its proximal promoter is preferentially active in human retinoblastoma cells

Purpose

Retinoblastoma (RB) is a malignant childhood intraocular tumor. Current treatment options for RB have undesirable side effects. A comprehensive understanding of gene expression in human RB is essential for the development of safe and effective new therapies.

Methods

We reviewed published microarray and RNA sequencing studies in which gene expression profiles were compared between human RB and normal retina tissues. We investigated the expression of genes of interest using quantitative reverse transcription PCR. We examined the activities of cloned promoter DNA fragments with luciferase assay.

Results

Dopachrome tautomerase (DCT) was among the most overexpressed genes in RB in published studies. We found that DCT was highly expressed in six of 13 samples microdissected from Thai RB tissues. Expression of DCT was absent or barely detected in retina tissues, various human ocular cells, and major organs. We also demonstrated that the -657 to +411 DCT promoter fragment efficiently directs RB cell-specific transcription of the luciferase reporter gene in cell lines.

Conclusions

The present work highlights that DCT is one of the most RB-specific genes. The regulatory elements required for this cell-specific gene expression are likely located within its proximal promoter.

Growth Inhibition of Retinoblastoma Cell Line by Exosome-Mediated Transfer of miR-142-3p

Introduction

Retinoblastoma (Rb) is the most common ocular paediatric malignancy and is caused by a mutation of the two alleles of the tumor suppressor gene, RB1. The tumor microenvironment (TME) represents a complex system whose function is not yet well defined and where microvesicles, such as exosomes, play a key role in intercellular communication. Micro-RNAs (mRNAs) have emerged as important modifiers of biological mechanisms involved in cancer and been able to regulate tumor progression.

Methods

Co-culture of monocytes with retinoblastoma cell lines, showed a significant growth decrease. Given the interaction between Rb cells and monocytes, we investigated the role of the supernatant in the cross-talk between cell lines, by taking the product of the co-culture and then using it as a culture medium for Rb cells.

Results

miR-142-3p showed to be particularly over-expressed both in the Rb cell line and in the medium used for their culture, comparing to control cell line and the normal supernatant, respectively. Therefore, we provided evidence that miR-142-3p is released by monocytes in the co-culture medium’s exosomes and that it is subsequently up-taken by Rb cells, causing the inhibition of proliferation of Rb cell line by affecting cell cycle progression.

Conclusion

This study highlights the role of exosomic miR-142-3p in the TME of Rb and identifies new molecular targets, which are able to control tumor growth aiming the development of a forward-looking miR-based strategy.

Carboplatin- and Etoposide-Loaded Lactoferrin Protein Nanoparticles for Targeting Cancer Stem Cells in Retinoblastoma In Vitro

Purpose

Cancer stem cells (CSCs) are known to contribute to tumor relapses by virtue of their chemoresistance. With the knowledge that nanoformulations can overcome drug resistance, we evaluated the efficacy and cytotoxicity of clinical-grade carboplatin (CPT)– and etoposide (ETP)–loaded lactoferrin nanoparticles (Lf-Nps) on total, CD133-enriched (non-CSC), and CD133-depleted (CSC) populations of retinoblastoma (Rb) Y79 cells.

Methods

Physicochemical properties of drug-loaded Lf-Nps were measured with transmission electron microscopy and attenuated total reflectance–Fourier transform infrared. The encapsulation efficiency, uptake, and release of drug-loaded Lf-Nps were measured using high-performance liquid chromatography and a UV-visible spectrophotometer. Cytotoxicity of the standard and drug-loaded Lf-Nps was evaluated by the MTT assay.

Results

The mean (SD) size and encapsulation efficiency of Lf-CPT and Lf-ETP were 61.2 (3.94) nm, 60% and 45.15 (5.85) nm, 38%, respectively, and the drug release efficiency was highest at pH 6. The increased drug uptake and lower release of drug-loaded Lf-Nps were observed in CSC and non-CSC populations compared to their standard forms. The relative increase of drug uptake and sustained intracellular retention of the drug-loaded Lf-Nps compared to standard drugs showed an enhanced cytotoxicity up to 50%, especially in Rb Y79 CSCs (IC₅₀: CPT, 230.3; Lf-CPT, 118.2; ETP, 198.1; and Lf-ETP, 129) compared to non-CSCs.

Conclusions

Our study documents an increase in drug uptake, retention, and cytotoxicity of Lf-CPT and Lf-ETP on Y79 CSCs and non-CSCs as compared to their standard drugs in vitro. The reversal of chemoresistance in the CSC population by nanoformulation appears promising with the potential to pave the way for improved targeted therapy and better clinical outcomes.

High-Risk Histopathologic Features of Retinoblastoma Treated at a Tertiary Hospital in West Java, Indonesia

PURPOSE

To evaluate the histopathological characteristics of clinically advanced retinoblastoma (RB) and its relationship with tumor differentiation.

METHODS

This was a cross-sectional study of primary enucleated group D/E intraocular RB using medical records from 2017 to 2020 in a tertiary referral hospital. Cases with incomplete histopathological results were excluded. Tumors were classified into well, moderately, and poorly differentiated and undifferentiated. High-risk histopathological features were classified as per Thaung and Karaa [Community Eye Health. 2018;31(101):17-3].

RESULTS

This study included 121 patients (129 eyes), of which 32.2% were diagnosed at 25-36 months. High-risk features (HRFs) were found in 100/129 eyes, and of 73 complete histopathological results, the 2 most common HRFs were postlaminar optic nerve invasion and massive choroidal invasion. RB was poorly differentiated in 69.9% and well differentiated in 12.3% of eyes. There was no statistically significant association between any HRFs and tumor differentiation, with age >2 years associated with tumor differentiation (p < 0.05).

CONCLUSION

The frequency of HRFs is 77.5% of primary enucleated eyes, mainly poorly and undifferentiated cells, particularly in children aged >2 years old.

Less is more: new one-step intracameral chemotherapy technique

Purpose: To describe the feasibility of a new one-step approach to aspirate the aqueous and apply melphalan in a single-go without repeated entries into the anterior chamber. Methods: This retrospective non-comparative study was conducted at a referral center and included 12 patients. The one-step approach is described in a step-wise manner. No complications were observed among the patients. Results: One single injection of intracameral melphalan proved to be a successful treatment in nine cases. Two patients required a second injection, which was administered two weeks after the first one following the same technique. Conclusions: This proved to be a reasonable technique for the smooth application of melphalan in the anterior chamber studded with retinoblastoma seeds. Our outcomes revealed that it is an effective, quick, and cost-effective technique. Longer-term data collection is underway, though initial findings are encouraging.

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.

Interventional neuro-oncology

Interventional neuro-oncology encompasses an array of image-guided therapies-intra-arterial chemotherapy, regional drug delivery, chemoembolization, tumor ablation-along with techniques to improve therapy delivery such as physical or chemical blood-brain barrier disruption and percutaneous catheter placement. Endovascular and percutaneous image-guided approaches to the treatment of the brain, eye, and other head and neck tumors will be discussed.

Cancer Stem Cells with Overexpression of Neuronal Markers Enhance Chemoresistance and Invasion in Retinoblastoma

BACKGROUND

Retinoblastoma is a sight and life-threatening embryonal tumor in children. Though chemotherapy is the main mode of therapy, evolving resistance remains a major obstacle in treatment success. The presence of cancer stem cells (CSC) is frequently reported to be responsible for chemoresistance in multiple tumors.

OBJECTIVE

Our study aims to identify the molecular factors that facilitate the chemoresistance through cancer stem cells in retinoblastoma.

METHODS

We developed etoposide and carboplatin resistant retinoblastoma (Y79) cell lines by stepwise drug increment treatment, validated with MTT and TUNEL assays. Colony forming and invasive ability were studied by soft-agar colony forming and transwell assays, respectively. Similar analysis in non-responsive retinoblastoma tumors were carried out by histopathology. Finally, expression of CSC/neuronal markers and ABC transporters were examined by quantitative PCR and protein expression of neuronal stem cell markers was confirmed by Western blot.

RESULTS

Larger colony size of resistant cells in soft-agar assay provided evidence for increased selfrenewability. Histopathology in non-responsive tumors showed poorly differentiated cells predominantly. Besides, both resistant cell lines and non-responsive tumors showed increased invasion with higher expression of neuronal stem cell markers - SOX2, NANOG, OCT4 and ABC transporters - ABCB1 and ABCC3. Increased self-renewal ability and invasion along with overexpression of stemness markers in resistant cells and tumors provide evidence for stemness driving chemoresistance and invasion in retinoblastoma.

CONCLUSION

We have demonstrated Neuronal stem cell/CSC markers that facilitate the maintenance of cancer stem cells. Developing therapies targeting these factors will help in overcoming resistance and improving retinoblastoma treatment.

Combined association of massive choroidal and optic nerve invasion as a prognostic relevance in primary retinoblastoma: A 10-year study

PURPOSE

To determine the significance of both massive choroidal invasion and optic nerve invasion (retrolaminar [(RL]+cut end [CE]) as a criterion for classifying high metastatic potential retinoblastoma and their relationship with other known histopathological high-risk features.

METHODS

A retrospective review of 650 eyes diagnosed as retinoblastoma over a 10-year period. In our study, there is male predominance and a higher percentage of the poorly differentiated tumors. The age of most of the patients ranges from 1 month to 8 years with a median age of 2 years.

RESULTS

There were 24% of eyes with massive choroidal invasion and 18% of eyes with optic nerve invasion up to the cut end. On performing Cox-proportional hazard analysis, it was found that massive choroidal invasion in association with optic nerve invasion up to the cut end was an independent prognostic parameter. On Kaplan-Meier analysis, overall survival had reduced in patients having both massive choroidal invasion and an optic nerve cut end invasion along with orbital invasion (P < .05).

CONCLUSION

The presence of massive choroidal invasion in association with optic nerve cut end invasion (RL+CE) could be used as a better prognostic predictor in assessing retinoblastoma patients with high metastatic potential and need to be kept for longer follow up.

Childhood cancer in India

India has made significant improvement in childhood cancer services in last few decades. However, the outcome still remains modest as compared to global standards due to significant barriers in recognition, diagnosis and cure. Data regarding comprehensive childhood cancer burden in country is lacking due to low and urban predominant coverage of population-based cancer registry programs. The available data shows lower incidence of childhood cancer incidence especially in leukaemia and CNS tumours which may suggest poor awareness of caregivers and delayed diagnosis with many "missed cases". Incidence data are also skewed towards male preponderance which suggests gender bias in seeking healthcare. The childhood cancer services in India are predominantly restricted to few tertiary care centres in major cities. The outcome in major groups of cancer is complicated by delayed and more advanced stage of presentation and poor supportive care during intensive treatment. Treatment refusal and abandonment remains major hurdles. Last few decades saw development of dedicated paediatric oncology services and training programs in the country. The development of InPOG (Indian Paediatric Oncology group) for conducting collaborative trials will lead to adoption of uniform treatment protocols suited for the country. Financial support through the government promoted health insurance and holistic support through philanthropic organizations have improved treatment adherence and outcome. Moving forward, the focus should be on strengthening the cancer registries for capturing nationwide data, improving awareness of childhood cancer among caregivers and healthcare workers for early recognition and improving accessibility of childhood cancer care services beyond major cities.

HDAC6 inhibitor WT161 induces apoptosis in retinoblastoma cells and synergistically interacts with cisplatin

Background

WT161 is a recently discovered histone deacetylase 6 (HDAC6) inhibitor which shows anti-tumor effects on multiple myelomas and breast cancer. However, the role of WT161 in retinoblastoma remains unclear. The aim of this study is to explore the role of WT161 in retinoblastoma and its underlying mechanisms.

Methods

The anti-proliferation of WT161 on retinoblastoma cells was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and soft agar colony formation assay. Cell apoptosis was analyzed using flow cytometer. WT161 and DDP synergistic effect was evaluated by isobologram analysis using CompuSyn software.

Results

WT161 suppressed the cell growth and induced apoptosis of retinoblastoma cells in a dose- and time-dependent manner. Mechanistically, WT161 increases the transcription of Bad through activating Bad promoter. Chromatin immunoprecipitation (ChIP) assay showed WT161 treatment increased acetylated histone H3 (AcH3) and acetylated histone H4 (AcH4) on the Bad promoter in retinoblastoma cells. In addition, WT161 shows synergistically inhibitory effects on retinoblastoma cell combined with cisplatin.

Conclusions

These results indicate that WT161, as a selective HDAC6 inhibitor, is a promising agent against retinoblastoma.

MicroRNA‑330 is downregulated in retinoblastoma and suppresses cell viability and invasion by directly targeting ROCK1

Abnormal expression of microRNAs (miRNAs/miRs) has been previously reported in various types of human cancer, such as retinoblastoma (RB). Dysregulated miRNAs have been demonstrated to be important epigenetic regulators of numerous biological events associated with RB. Therefore, improved understanding of the precise roles of miRNAs in RB is required to develop novel therapeutic strategies for the treatment of patients with this disease. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑330 expression in RB tissues and cell lines. The effects of miR‑330 overexpression on the viability and invasion of RB cells were determined using MTT and Matrigel®‑based invasion assays, respectively. The mechanisms underlying the activity of miR‑330 in RB cells were investigated via bioinformatics analysis, luciferase reporter assays, and RT‑qPCR and western blot analyses. It was revealed that the levels of miR‑330 expression were significantly downregulated in RB tissues and cell lines compared with in control healthy tissues and cells, respectively. Overexpression of miR‑330 in RB cells significantly reduced the viability and invasion of cells in vitro. Additionally, ρ‑associated coiled‑coil containing protein kinase 1 (ROCK1) was identified as a putative target of miR‑330 using bioinformatics analysis. Subsequent experiments revealed that miR‑330 interacted with the 3'‑untranslated region of ROCK1 and downregulated its expression in RB cells. Furthermore, the expression levels of ROCK1 were increased in RB tissues compared with healthy controls and negatively correlated with miR‑330 expression. Finally, upregulation of ROCK1 expression reversed the miR‑330‑induced inhibition of the viability and invasion of RB cells. Collectively, these results suggested that miR‑330 exhibits tumor‑suppressor activity in the development of RB by directly targeting ROCK1, indicating that restoration of miR‑330 expression may be a promising therapeutic technique in the treatment of patients with RB.

Smartphone-based application improves the detection of retinoblastoma

PURPOSE

To improve and validate the smartphone-based leukocoria detection application so that non-ophthalmologists could make use of the smartphone for early detection of Retinoblastoma (RB) in young children without anesthesia and pharmacological dilatation of the pupil.

METHODS

Two apps, MDEyeCare and CRADLE, developed for red reflex based leukocoria detection were used in iPhone 6s. MDEyeCare methodology was modified with respect to ambient lighting, the distance between camera and eye and different gazes for better performance. We analyzed totally 34 eyes of 23 RB patients and four normal children. Each of the RB patients was confirmed with clinical examination and radiological investigations.

RESULTS

Modification in the methodology of MDEyeCare app could detect the leukocoria in early stages of RB (50% of Group B, 83% of Group C). In late stages (Group D and E), 100% of tumors were detected. The CRADLE app failed to provide adequate leukocoria detection except four late stage RB eyes. Among the 14 normal eyes (6 from unilateral RB and eight from normal children), pseudo-leukocoria was observed in three eyes only at lateral gaze even with MDEyeCare app.

CONCLUSION

Improved methodology in smartphone-based app enhanced the detection of RB and this may translate into better outcome after treatment with respect to vision salvage.

Knockdown of lncRNA-H19 inhibits cell viability, migration and invasion while promotes apoptosis via microRNA-143/RUNX2 axis in retinoblastoma

BACKGROUND

Even though the role of long non-coding RNA H19 (lncRNA-H19) in diverse cancer types has been studied, exact effect of lncRNA-H19 as well as the underlying mechanism in retinoblastoma (RB) is poorly reported. We aimed to explore the possible functions of lncRNA-H19 in human RB Y79 cells.

METHODS

LncRNA-H19 in Y79 cells was silenced, and effects of lncRNA-H19 silence on cell viability, migration and invasion, and apoptosis were analyzed by using trypan blue exclusion, Transwell assay, and flow cytometry assay/Western blot analysis, respectively. Then, miR-143 expression in cells with lncRNA-H19 silence was determined by RT-qPCR, and effects of miR-143 inhibition on lncRNA-H19-suppressing cells were assessed. Whether RUNX2 was a target of miR-143 and the involved signaling pathways in the modulation of miR-143 were also studied.

RESULTS

LncRNA-H19 knockdown repressed cell viability, migration and invasion while promoted apoptosis in Y79 cells. miR-143 was a downstream factor of lncRNA-H19, and its inhibition reversed the effects of lncRNA-H19 silence on Y79 cells. RUNX2 was a target gene of miR-143, and miR-143 was found to affect Y79 cells via down-regulation of RUNX2. Phosphorylation of key kinases related in the PI3K/AKT/mTOR pathways was reduced by miR-143 via regulation of RUNX2.

CONCLUSION

Knockdown of lncRNA-H19 acted a tumor suppressive role in Y79 cells through up-regulating miR-143. Moreover, miR-143 exerted tumor suppressive effects on Y79 cells by targeting RUNX2, along with inhibition of the PI3K/AKT/mTOR pathways.

Targeting Notch signaling as a novel therapy for retinoblastoma

Retinoblastoma is the most common intraocular malignancy of childhood. Notch plays a key role in retinal cells from which retinoblastomas arise, and we therefore studied the role of Notch signaling in promoting retinoblastoma proliferation. Moderate or strong nuclear expression of Hes1 was found in 10 of 11 human retinoblastoma samples analyzed immunohistochemically, supporting a role for Notch in retinoblastoma growth. Notch pathway components were present in WERI Rb1 and Y79 retinoblastoma lines, with Jag2 and DLL4 more highly expressed than other ligands, and Notch1 and Notch2 more abundant than Notch3. The cleaved/active form of Notch1 was detectable in both lines. Inhibition of the pathway, achieved using a γ-secretase inhibitor (GSI) or by downregulating Jag2, DLL4 or CBF1 using short hairpin RNA, potently reduced growth, proliferation and clonogenicity in both lines. Upregulation of CXCR4 and CXCR7 and downregulation of PI3KC2β were identified by microarray upon Jag2 suppression. The functional importance of PI3KC2β was confirmed using shRNA. Synergy was found by combining GSI with Melphalan at their IC₅₀. These findings indicate that Notch pathway is active in WERI Rb1 and Y79, and in most human retinoblastoma samples, and suggest that Notch antagonists may represent a new approach to more effectively treat retinoblastoma.

Improved procedural safety following protocol changes for selective ophthalmic arterial infusion of chemotherapy for treatment of ocular retinoblastoma

Purpose The aim was to evaluate the impact of protocol changes in selective ophthalmic arterial infusion (SOAI) for treatment of retinoblastoma (Rb). Methods A retrospective review was completed of 35 patients with Rb who were treated with SOAI between March 2010 and January 2017. Treatment details were tabulated for each SOAI session. SOAI protocol was changed in June 2015, and differences before and after this change were evaluated using two-tail chi-square tests and independent sample t-tests to note any differences in technical complications, need for enucleation, and other outcome variables Results 125 SOAI sessions occurred. No technical complications occurred during the study. Two complications (1.6%) occurred in the postoperative setting. Both complications occurred prior to the change in protocol. Comparing the complication rates between the two protocols showed no significant difference (2.2% versus 0.0%; p = 0.505); 29 of 43 (67.4%) eyes had their vision preserved overall. Conclusions SOAI is an effective treatment for Rb. The refined protocol described herein was associated with fewer complications.

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.

Tetramethylpyrazine-mediated regulation of CXCR4 in retinoblastoma is sensitive to cell density

Retinoblastoma is the most common ocular tumor in children, and it causes extensive damage. Current treatment options for retinoblastoma include surgery, chemotherapy, radiotherapy and cryotherapy. However, the majority of chemotherapy medicines cause complications and side effects that lead to severe impairment of patient health. Previous studies have reported that tetramethylpyrazine (TMP), which is an extract of the Chinese herbal medicine Chuanxiong, reduces the risk of multidrug resistance in chemotherapy and inhibits the proliferation and metastasis of various types of cancer cells. However, the underlying molecular mechanism of TMP in retinoblastoma remains unclear. The current study demonstrated that C-X-C chemokine receptor type 4 (CXCR4) was expressed in WERI-Rb1 cells and in retinoblastoma. Using reverse transcription-quantitative polymerase chain reaction and western blotting techniques, the current study demonstrated that TMP significantly downregulated the expression of CXCR4 in WERI-Rb1 cells cultured at high density, whereas it had a minor effect in low-density WERI-Rb1 cells; additionally, this effect occurred in a time-dependent manner. TMP inhibited the proliferation of WERI-Rb1 cells as effectively as a CXCR4 antagonist, AMD3100, consistent with a role of CXCR4 in cancer development. Notably, TMP did not affect the cell cycle of cells cultured at low density (1×10⁵ cells/ml), whereas it induced G1-phase arrest in high-density cells (7.5×10⁵ cells/ml; P<0.05). In addition, the expression of CXCR4 in primary rat retinal neurocytes was significantly downregulated by TMP treatment, and this treatment protected primary rat retinal neurocytes from H₂O₂-induced damage. Thus, the results of this study indicate that TMP is a potential candidate for use in treatment of retinoblastoma, and also provides novel insights into the mechanisms of the anti-cancer and neuroprotective effects of this extract.

miR-124 inhibits proliferation and invasion of human retinoblastoma cells by targeting STAT3

A growing body of evidence suggests that microRNA-124 (miR-124) functions as tumor-suppressor, and involves in tumor initiation, development and metastasis in major classes of human cancers; however, the biological role and underlying molecular mechanism of miR-124 in retinoblastoma (RB) remain unknown. Therefore, we investigated the biological activity and underlying molecular mechanism of miR-124 in human retinoblastoma. In the present study, our results demonstrated the downregulation of miR-124 in RB tissues and RB cell lines compared with normal retinal tissues. The ectopic expression of miR-124 in the RB cell lines (Y79 and SO-RB50) suppresses cell proliferation, migration and invasion, induced cell apoptosis in vitro. Furthermore, signal transducer and activator of transcription 3 (STAT3) was identified as a new target of miR-124, and overexpression of miR-124 decreased STAT3 expression on mRNA level and protein level in human RB cells. We also found that STAT3 mRNA expression was upregulated and inversely correlated with miR-124 expression in the RB tissues (r=-0.683; P<0.001). Restoration of the expression of STAT3 rescues the effects induced by miR-124 in RB cells. The findings of the present study suggested that miR-124 functioned as tumor suppressor in RB, at least in part, by targeting STAT3, and that it could serve as a potential candidate for RB therapeutics.

Depression, caregiver burden and social support among caregivers of retinoblastoma patients in China

The aim of this study is to examine the burden of family caregivers of patients with retinoblastoma in China and the relationships between depression, caregiver burden and social support. A descriptive and correlational survey was conducted with 117 Chinese family caregivers of outpatient patients with retinoblastoma from the Department of Ophthalmology of a tertiary hospital in Shanghai, China. Family caregivers of outpatient patients with retinoblastoma were asked to respond to four questionnaires including sociodemographic questionnaire, Becker Depression Inventory, Caregiver Burden Inventory and Social Support Rating Scale. The incidence of depression in this study was 51.3%; the average score for social support indicated moderate social support available to the caregivers, although their level of caregiver burden was heavy. Depression scores were significantly positively correlated with caregiver burden scores and significantly negatively correlated with the social support scores. Heavy caregiver burden was associated with lower monthly income, low subjective social support and less use of social support.

Outcomes of Intra- and Extraocular Retinoblastomas from a Single Institute in South India

AIM

To report treatment outcomes of intra- and extraocular retinoblastomas seen at Aravind Eye Hospital, Coimbatore, South India.

METHODS

Retrospective case series from January 2006 to December 2011 involving 106 babies. Clinical records were reviewed and data collected on presenting signs, gender, age, family history, ocular findings and treatment outcomes. All eyes were classified using the International Retinoblastoma Classification.

RESULTS

The mean follow up was 35.4 months (range 1-75 months, SD 20.2, median 33 months). The mean age of presentation was 20.8 months (range 5 days to 120 months). There were 68 unilateral and 38 bilateral cases. Globe salvage rates were 100% for group A (11 eyes), B (16 eyes) and C (2 eyes). For group D, eye salvage rate was 29.5% (10/34 eyes). Survival rate of orbital retinoblastoma in our study was 55.5% (5/9 cases) at a mean follow up of 33.6 months. The overall patient survival rate was 89.6% with 11 deaths (10.4%). The commonest cause of death (7/11) was distant metastasis due to refusal to take initial treatment.

CONCLUSION

Greater improvement in patient survival can be achieved not only by early treatment of intraocular disease but also to convince patients to accept treatments including enucleation in this part of the world.

An extremely rare case of metastatic retinoblastoma of parotids presenting as a massive swelling in a child

Retinoblastoma (Rb) is a common childhood malignancy but bilateral Rb with metastasis to parotids is very uncommon. To the best of our knowledge, bilateral Rb metastasizing to parotids is very rare and this is the fifth such case reported in world literature till date in a 2-year-old male child who underwent exenteration of left eye for bilateral Rb and later developed recurrent metastasis to left parotid requiring parotidectomy. A year later he presented again with swelling left parotid region extending from occipital region reaching upto left anterior chest wall with intra-cranial extension on magnetic resonance imaging. Histopathological examination of the parotid swelling and immunohistochemistry showed metastasis from Rb. He was treated with chemotherapy followed by radiotherapy to local site and brain to which he responded well. Presently on regular follow up without any signs of locoregional and distal metastasis. Till date different types of primary parotid tumors have been reported in literature but a metastatic parotid tumor is extremely rare and therefore this case is being reported to highlight the extreme rarity, the diagnostic and therapeutic challenges, the highly aggressive nature and overall dismal prognosis of this disease entity.

Tobacco Use Increases Oxidative DNA Damage in Sperm - Possible Etiology of Childhood Cancer

BACKGROUND

Cigarette smoking and tobacco chewing are common modes of consuming tobacco all over the world. Parents need to be aware that germ cell integrity is vital for birth of healthy offspring as biological parenting begins much before birth of a child and even before conception. The present study was conducted to determine the etiology of non-familial sporadic heritable retinoblastoma (NFSHRb), by evaluating oxidative sperm DNA damage in fathers due to use of tobacco (smoking and chewing).

MATERIALS AND METHODS

We recruited 145 fathers of NFSHRb children and 53 fathers of healthy children (controls) in the study. Tobacco history was obtained by personal interview. Seminal reactive oxygen species (ROS) in semen, sperm DNA fragmentation index (DFI) and 8 hydroxy 2' deoxyguanosine (8-OHdG) levels in sperm were evaluated. The RB1 gene was screened in genomic blood DNA of parents of children with NFSHRb and controls. Odds ratios (ORs) derived from conditional logistic regression models.

RESULTS

There was significant difference in the levels of ROS (p<0.05), DFI (p<0.05) and 8-OHdG (p<0.05) between tobacco users and non-users. The OR of NFSHRb for smokers was 7.29 (95%CI 2.9-34.5, p<0.01), for tobacco chewers 4.75 (2.07-10.9, p<0.05) and for both 9.11 (3.79-39.2; p<0.01).

CONCLUSIONS

This study emphasizes the adverse effect of tobacco on the paternal genome and how accumulation of oxidative damage in sperm DNA may contribute to the etiology of NFSHRb. In an ongoing parallel study in our laboratory, 11 of fathers who smoked underwent. Meditation and yoga interventions, showed significant decline in levels of highly mutagenic oxidised DNA adducts after 6 months. Thus our lifestyle and social habits impact sperm DNA integrity and simple interventions like yoga and meditation are therapeutic for oxidative damage to sperm DNA.

Management of retinoblastoma: opportunities and challenges

Nano-delivery systems have significantly evolved over the last decade for the treatment of cancer by enabling site-specific delivery and improved bioavailability. The widely investigated nanoparticle systems are biodegradable polyesters, dendrimers, liposomes, mesoporous silica and gold nanoparticles. These particles when conjugated with different targeting motifs enhance the therapeutic efficiency of the drug molecules and biocompatibility. However, the application of such systems towards the treatment of retinoblastoma (RB), a rapidly spreading childhood eye cancer, still remains in its infancy. Nanoparticle-based systems that have been investigated for RB therapy have displayed improved drug delivery to the most restricted posterior segment of the eyes and have increased intra-vitreal half-life of the chemotherapy agents highlighting its potential in treatment of this form of cancer. This review focuses on the challenges involved in the treatment of RB and highlights the attempts made to develop nano-dimensional systems for the treatment of RB.

Retinoblastoma: experience of a referral center in the North Region of Portugal

Purpose

To describe the experience of the Ophthalmology Department of Hospital São João (HSJ), a tertiary health care center in North Region, Portugal, in terms of the diagnosis, treatment, and follow-up of retinoblastoma.

Methods

This was a retrospective study of patients diagnosed with retinoblastoma in Hospital São João, between 1978 and 2012.

Results

Fifty patients with retinoblastoma were evaluated in our institution between 1978 and 2012. Four patients were excluded due to loss of follow-up. Among the 46 retinoblastoma cases, 33 (71.7%) were unilateral and 13 (28.3%) bilateral, with a mean age at diagnosis of 22.19 months and 6.92 months, respectively (P<0.001). Leukocoria was the most common presenting sign (36.9%), followed by strabismus (19.6%), a combination of leukocoria and strabismus (8.7%), and buphthalmia (2.2%). Between 1978 and 1992, nine retinoblastoma cases were referred to our hospital, all of them unilateral, and, in each case, enucleation was performed, with or without salvage therapy. Between 1993 and 2012, 18 eyes with retinoblastoma were successfully managed with conservative treatment.

Conclusion

Demographic results were generally coincident with previous reports. It is crucial to screen leukocoria in pediatric practice, even in asymptomatic children. The outcome of retinoblastoma treatment in our hospital is similar to other series in developed countries.