Prognostic significance of NADPH oxidase-4 as an indicator of reactive oxygen species stress in human retinoblastoma

Ophthalmic wild olive (ACEBUCHE) oil nanoemulsions exert oculoprotective effects against oxidative stress induced by arterial hypertension

Oxidative stress plays a key role in several systemic and ocular diseases, including hypertensive eye diseases. In this context, we previously showed that oral administration of wild olive (acebuche, ACE) oil from Olea europaea var. sylvestris can counteract ocular damage secondary to arterial hypertension by modulating excess reactive oxygen species (ROS) produced by the enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Therefore, this work describes the development of an ACE oil-based formulation for ocular administration as a local therapy to counteract hypertension-related oxidative damage. Specifically, ACE oil nanoemulsions (NEs) were successfully produced and characterized, exhibiting appropriate features for ophthalmic administration, including a nanometer size (<200 nm), moderate negative ZP, adequate osmolality and pH, and colloidal stability in biorelevant fluids. Likewise, the NEs presented a shear thinning behavior, especially convenient for ocular instillation. In vivo evaluation was performed through either intravitreal injection or topical ophthalmic administration in mice with hypertension induced via administration of Nω-nitro-L-arginine-methyl-ester (L-NAME). Both routes of administration reduced hypertensive morphological alterations and demonstrated a noticeable antioxidant effect thanks to the reduction of the activity/expression of NADPH oxidase in cornea and retina. Thus, an ACE oil ophthalmic formulation represent a promising therapy for ocular pathologies associated with arterial hypertension.

Adjuvant Chemotherapy Improves Survival for Children With Massive Choroidal Invasion of Retinoblastoma

Purpose

The purpose of this study was to investigate the effect of adjuvant chemotherapy on outcomes of children with massive choroidal invasion (MCI).

Methods

In this study, we reviewed the 5-year relapse-free survival (RFS) and overall survival (OS) of children diagnosed with MCI, managed with or without adjuvant chemotherapy. Excluded were children with additional other high-risk features (post-laminar optic nerve invasion, scleral invasion, or overt extraocular disease).

Results

Of 3566 children diagnosed with retinoblastoma, 2023 had enucleation, and 60 eyes of 60 children had pathology showing MCI without concomitant high-risk features. Enucleation was primary (22, 37%), or secondary (38, 63%) after failed eye salvage. Adjuvant systemic chemotherapy (median = 4, range = 1-8 cycles) was given to 48 of 60 (80%) children; 12 of 60 (20%) children had no adjuvant therapy. Five-year RFS was 88.5% (95% confidence interval [CI] = 79.7%-97.3%) and 5-year OS was 90.1% (95% CI = 81.7%-98.5%). Pre-enucleation chemotherapy did not affect RFS (89.7% vs. 75.0%; P = 0.657). Adjuvant chemotherapy improved RFS (97.2% vs. 55.6%; P < 0.001) and OS (97.2% vs. 66.7%; P < 0.001). In subgroup analysis, adjuvant chemotherapy improved RFS for both primarily enucleated (5-year RFS 100% vs. 50.0%; P = 0.002) and secondarily enucleated children (5-year RFS 95.8% vs. 60.0%; P = 0.005). The number of children treated with adjuvant chemotherapy to prevent one post-enucleation systemic relapse or death is three.

Conclusions

Adjuvant chemotherapy significantly decreased the risk of tumor relapse and death for children with pathological MCI. For every three children treated with adjuvant chemotherapy, one systemic relapse or death could be prevented.

Prognostic Value of NOX4 Expression in Cancer Patients: A Systematic Review and Meta-analysis

Background. Recent studies have shown that nicotinamide adenosine dinucleotide phosphate oxidase 4 (NOX4) is related to cancer development, proliferation, invasion, epithelial-to-mesenchymal transition, and metastasis. The prognostic value of NOX4 expression although has been reported in various cancers, it remains unclear as several studies have reported conflicting results. Therefore, the purpose of this study was to systematically investigate the prognostic value of NOX4 expression in cancer patients. Method. Appropriate studies were collected by searching the PubMed, EMBASE, and Cochrane library databases, and the prognostic value of NOX4 expression in cancer patients was assessed through a meta-analysis. Results. Nine eligible studies involving 2675 cancer patients were included in this meta-analysis. We found that NOX4 expression is related to prognosis in cancer patients. In particular, high expression of NOX4 was significantly associated with overall survival in patients with gastrointestinal cancer (hazard ratio [HR]: 1.83, 95% confidence interval [CI]: 1.39–2.42, $p<0.001$ ). Conclusion. NOX4 expression is significantly correlated with overall survival in patients with gastrointestinal cancer, indicating that it could be a potential prognostic marker.

Oxidative Stress and the Role of NADPH Oxidase in Glaucoma

Glaucoma is characterised by loss of retinal ganglion cells, and their axons and many pathophysiological processes are postulated to be involved. It is increasingly understood that not one pathway underlies glaucoma aetiology, but rather they occur as a continuum that ultimately results in the apoptosis of retinal ganglion cells. Oxidative stress is recognised as an important mechanism of cell death in many neurodegenerative diseases, including glaucoma. NADPH oxidase (NOX) are enzymes that are widely expressed in vascular and non-vascular cells, and they are unique in that they primarily produce reactive oxygen species (ROS). There is mounting evidence that NOX are an important source of ROS and oxidative stress in glaucoma and other retinal diseases. This review aims to provide a perspective on the complex role of oxidative stress in glaucoma, in particular how NOX expression may influence glaucoma pathogenesis as illustrated by different experimental models of glaucoma and highlights potential therapeutic targets that may offer a novel treatment option to glaucoma patients.

Sunitinib-induced oxidative imbalance and retinotoxic effects in rats

AIMS

Sunitinib (Su), a tyrosine kinase inhibitor, is one of the most commonly used anti-angiogenic drugs. Some studies have described retinal detachment and photoreceptor damage following systemic exposure to Su, despite beneficial effects achieved with local treatment of ocular pathologies. The aim of this study was to explore the role of NADPH oxidase system and oxidative stress in eyes from Su-treated animals.

MAIN METHODS

Male Wistar rats were administered 25 mg Su/kg body weight/day incorporated in the chow for 3 weeks. Upon treatment completion, NADPH oxidase activity and ROS levels were measured in ocular tissue by chemiluminescence and dihydroethidium (DHE) staining, respectively. The expression of NADPH oxidase isoforms (NOX1, NOX2 and NOX4), antioxidant enzymes and endothelial/inducible nitric oxidase isoforms (eNOS/iNOS) in the eyecup and/or retina were measured via immunofluorescence, immunoblotting and RT-qPCR.

KEY FINDINGS

NADPH oxidase activity/expression increased in eyecup and retinas from Su-treated rats. Immunohistofluorescence studies in retinal layer confirmed a higher signal of NADPH oxidase isoforms after Su treatment. Treated animals also presented with reductions in NO levels and eNOS expression, whereas iNOS was upregulated. Finally, a significant depletion of antioxidant enzyme glutathione peroxidase was measured in eyecups of rats following Su exposure, and the opposite pattern was seen for glutathione reductase and superoxide dismutase.

SIGNIFICANCE

This study demonstrates that Su treatment is associated with NADPH oxidase-derived oxidative stress in the eye. Long-term treatment of Su should be properly monitored to avoid retinotoxic effects that might result in ocular pathologies and sight-threatening conditions.

Update on pathology of retinoblastoma

Retinoblastoma is caused by mutational inactivation of both alleles of the RB1 gene, which maps to chromosome 13q14 and encodes retinoblastoma protein that acts as a tumor suppressor. Histopathological high-risk features of retinoblastoma are predictive of metastasis or local recurrence. The focus of this update is to emphasize the recent advances in pathology, various molecular key pathways and genome wide approaches for newer potential therapeutic future targets associated with retinoblastoma tumor biology. This review article highlights the new biomarkers expressed by the retinoblastoma tumor for the better survival of patients.

Long noncoding RNA NEAT1 promotes the growth of human retinoblastoma cells via regulation of miR-204/CXCR4 axis

Retinoblastoma (RB) is an aggressive eye cancer of infancy and childhood with high mortality. Studies have shown that long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is closely related to the progression of multiple cancers. However, its role in RB remains unknown. This study aimed to investigate the role and underlying mechanism of NEAT1 in RB. We first detected the expression of NEAT1 in human RB tissues and cell lines. The effects of NEAT1 on the proliferation, migration, and apoptosis of RB cells were analyzed by loss-of-function. The underlying mechanism of NEAT1 in RB was mainly focused on the microRNA 204/C-X-C chemokine receptor type 4 (miR-204/CXCR4) axis. In addition, the role and mechanism of NEAT1 in RB were further evaluated in a mouse xenograft tumor model. We found NEAT1 and CXCR4 expression levels were elevated, whereas miR-204 expression was decreased in RB tissues and cells. Downregulation of NEAT1 significantly decreased the proliferation and migration but promoted the apoptosis of RB cells. NEAT1 functioned as a competing endogenous RNA for miR-204 to regulate CXCR4 expression. Knockdown of NEAT1 suppressed the tumor volume, tumor weight, and CXCR4 expression, whereas increased miR-204 expression in mice. In conclusion, NEAT1 promotes the development of RB via miR-204/CXCR4 axis, which provides a new target for the treatment of RB disease.

The Janus-Faced Role of Antioxidants in Cancer Cachexia: New Insights on the Established Concepts

Chronic inflammation and excessive loss of skeletal muscle usually occur during cancer cachexia, leading to functional impairment and delaying the cure of cancer. The release of cytokines by tumor promotes the formation of reactive oxygen species (ROS), which in turn regulate catabolic pathways involved in muscle atrophy. ROS also exert a dual role within tumor itself, as they can either promote proliferation and vascularization or induce senescence and apoptosis. Accordingly, previous studies that used antioxidants to modulate these ROS-dependent mechanisms, in cancer and cancer cachexia, have obtained contradictory results, hence the need to gather the main findings of these studies and draw global conclusions in order to stimulate more oriented research in this field. Based on the literature reviewed in this paper, it appears that antioxidant supplementation is (1) beneficial in cancer cachectic patients with antioxidant deficiencies, (2) most likely harmful in cancer patients with adequate antioxidant status (i.e., lung, gastrointestinal, head and neck, and esophageal), and (3) not recommended when undergoing radiotherapy. At the moment, measuring the blood levels of antioxidants may help to identify patients with systemic deficiencies. This approach is simple to realize but could not be a gold standard method for cachexia, as it does not necessarily reflect the redox state in other organs, like muscle.