Genetic screening in Iranian patients with retinoblastoma

The Traces of Dysregulated lncRNAs-Associated ceRNA Axes in Retinoblastoma: A Systematic Scope Review

PURPOSE

Long non-coding RNAs are an essential component of competing endogenous RNA regulatory axes and play their role by sponging microRNAs and interfering with the regulation of gene expression. Because of the broadness of competing endogenous RNA interaction networks, they may help investigate treatment targets in complicated disorders.

METHODS

This study performed a systematic scoping review to assess verified loops of competing endogenous RNAs in retinoblastoma, emphasizing the competing endogenous RNAs axis related to long non-coding RNAs. We used a six-stage approach framework and the PRISMA guidelines. A systematic search of seven databases was done to locate suitable papers published before February 2022. Two reviewers worked independently to screen articles and collect data.

RESULTS

Out of 363 records, fifty-one articles met the inclusion criteria, and sixty-three axes were identified in desired articles. The majority of the research reported several long non-coding RNAs that were experimentally verified to act as competing endogenous RNAs in retinoblastoma: XIST/NEAT1/MALAT1/SNHG16/KCNQ1OT1, respectively. At the same time, around half of the studies investigated unique long non-coding RNAs.

CONCLUSIONS

Understanding the many features of this regulatory system may aid in elucidating the unknown etiology of Retinoblastoma and providing novel molecular targets for therapeutic and clinical applications.

Impact of RB1 gene screening from blood collected on a single day from 411 family members of 113 Retinoblastoma survivors in India

OBJECTIVES

To analyse the profile and implication of genetic testing in a cohort of retinoblastoma (RB) patients and their families conducted on a single day during World Retinoblastoma Awareness Week 2017.

METHODS

Retrospective analysis of blood samples were collected from 411 subjects, including 113 probands at a camp organised for RB awareness and were analysed for RB1 mutations by Sanger sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA). If germline mutations were detected, the parents and siblings of the proband were tested for the same mutation.

RESULTS

Germline RB1 mutations were identified in 61/113(54%) probands with a mutation detection rate of 96% (47/49) and 22% (14/64) for bilateral and unilateral RB, respectively. Ten novel pathogenic mutations were identified. Splice mutation was most common (31%) followed by nonsense mutation (26%). The mean age at RB diagnosis was significantly lower in patients having germline RB1 mutation (mean 10.7 months ±2.5) compared to those without (mean 27.2 months ±6.5) (p = <0.0001). Parental transmission of the mutant allele was detected in 15/61(25%) cases of which 11(18%) parents were unaffected indicating incomplete penetrance. The origin of the variant allele was both paternal (n = 7) and maternal (n = 4) wherein 5 were bilateral and 6 unilateral.

CONCLUSIONS

The detection of a germline mutation impacts the proband and family members due to its implications on change in prognosis, frequency of subsequent evaluations, screening for ocular and non-ocular cancers, and surveillance of family and future progeny.

An update in the applications of exosomes in cancer theranostics: from research to clinical trials

Exosomes are nanosized extracellular vesicles secreted by nearly all viable cells following the fusing of multivesicular bodies and the plasma membrane and discharged into the encircling bodily fluids. Exosomes can transport cell-specific components from the source cell to the target cell. Given the enormous potential of exosomes as non-invasive diagnostic biomarkers and therapeutic nanovehicles. Lately, accumulated evidence has demonstrated that exosomes serve an important role in prognosis, diagnosis, and even treatment strategies. While several reviews have collective information on the biomedical application of exosomes, a comprehensive review incorporating updated and improved methodologies for beneficial applications of such vesicles in cancer theranostics is indispensable. In the current review, we first provided a comprehensive review of the introduction of exosomes, featuring their discovery, separation, characterization, function, biogenesis, secretion. The implications of exosomes as promising nanovehicles for drug and gene delivery, application of exosome inhibitors in the management of cancers, completed and ongoing clinical trials on the biological relevance of exosomes are then discussed in detail. As the field of exosome research grows, a better understanding of the subcellular parts and mechanisms involved in exosome secretion and targeting of specific cells will help figure out what their exact physiological functions are in the body.

Promotor methylation in ocular surface squamous neoplasia development: epigenetics implications in molecular diagnosis

INTRODUCTION

Cancer is heavily influenced by epigenetic mechanisms that include DNA methylation, histone modifications, and non-coding RNA. A considerable proportion of human malignancies are believed to be associated with global DNA hypomethylation, with localized hypermethylation at promoters of certain genes.

AREA COVERED

The present review aims to emphasize on recent investigations on the epigenetic landscape of ocular surface squamous neoplasia, that could be targeted/explored using novel approaches such as personalized medicine.

EXPERT OPINION

While the former is thought to contribute to genomic instability, promoter-specific hypermethylation might facilitate tumorigenesis by silencing tumor suppressor genes. Ocular surface squamous neoplasia, the most prevalent type of ocular surface malignancy, is suggested to be affected by epigenetic mechanisms, as well. Although the exact role of epigenetics in ocular surface squamous neoplasia has mostly been unexplored, recent findings have greatly contributed to our understanding regarding this pathology of the eye.

Effects of folate-conjugated Fe2O3@Au core-shell nanoparticles on oxidative stress markers, DNA damage, and histopathological characteristics: evidence from in vitro and in vivo studies

The aim of this work was to assess the cytotoxicity, genotoxicity, and histopathological effects of Fe2O3@Au-FA NPs using in vitro and in vivo models. Cytotoxicity and cellular uptake of nanoparticles (NPs) by HUVECs were examined via 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and inductively coupled plasma-mass-spectrometry (ICP-MS). This safe dose was then used for cytotoxicity assays, including total protein, total antioxidant capacity, lipid peroxidation, cell membrane integrity, reactive oxygen species, enzyme activity, and DNA damage. In the animal model, 32 Wistar rats were randomly categorized into 4 groups and received intraperitoneal injections of NPs. Blood samples for biochemical properties and histopathological changes were investigated. MTT results indicated 20 μg/ml as the safe dose for NPs. According to ICP-MS, treated cells showed significantly higher levels of the intracellular content of Fe (p < 0.001) and Au (p < 0.01) compared with the control group. In vitro tests did not show any significant cytotoxicity or genotoxicity at the safe dose of NPs. We found no significant elevation in intracellular γ-H2AX levels after treatment of HUVEC cells with Fe2O3@Au core-shell NPs (P > 0.05). As for the in vivo analysis, we observed no marked difference in serum biochemical parameters of rats treated with 50 mg/kg and 100 mg/kg doses of our NPs. Histopathological assessments indicated that liver, kidney, and testis tissues were not significantly affected at 50 mg/kg (liver), 50 mg/kg, and 100 mg/kg (kidney and testis) on NPs administration. These findings imply that the nanotoxicity of Fe2O3@Au-FA NPs in HUVECs and animals depends largely on the administrated dose. Our study suggests that Fe2O3@Au-FA NPs at a safe dose could be considered as new candidates in nanobiomedicine.

Reviewing the occurrence of large genomic rearrangements in patients with inherited cancer predisposing syndromes: importance of a comprehensive molecular diagnosis

INTRODUCTION

Hereditary cancer predisposition syndromes are caused by germline pathogenic or likely pathogenic variants in cancer predisposition genes (CPG). The majority of pathogenic variants in CPGs are point mutations, but large gene rearrangements (LGRs) are present in several CPGs. LGRs can be much more difficult to characterize and perhaps they may have been neglected in molecular diagnoses.

AREAS COVERED

We aimed to evaluate the frequencies of germline LGRs in studies conducted in different populations worldwide through a qualitative systematic review based on an online literature research in PubMed. Two reviewers independently extracted data from published studies between 2009 and 2020. In total, 126 studies from 37 countries and 5 continents were included in the analysis. The number of studies in different continents ranged from 3 to 48 and for several countries there was an absolute lack of information. Asia and Europe represented most of the studies, and LGR frequencies varied from 3.04 to 15.06% in different continents. MLPA was one of the methods of choice in most studies (93%).

EXPERT OPINION

The LGR frequencies found in this review reinforce the need for comprehensive molecular testing regardless of the population of origin and should be considered by genetic counseling providers.