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

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

Diagnostic Accuracy of Ultrasonography for Detection of Intussusception in Children; a Systematic Review and Meta-Analysis.

Introduction: The diagnosis of intussusception can be challenging in children due to the fact that the findings of clinical evaluations are nonspecific and most of the patients present with unclear history. Therefore, in this systematic review and meta-analysis, we aimed to investigate the diagnostic accuracy of ultrasonography for detection of intussusception and also compare the efficacy of point-of-care ultrasound (POCUS) with radiologist-performed ultrasound (RADUS). Methods: Two independent reviewers systematically searched different online electronic databases including MEDLINE, Scopus, Web of Science, Google Scholar, Embase, and Cochrane from inception to December 1, 2022 to identify published papers reporting accuracy of ultrasonography for diagnosis of intussusception. The quality assessment of the included studies was investigated using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. Results: A total of 1446 records were retrieved in the initial search of databases. After screening the titles, a total of 344 studies were retrieved for the detailed assessment of full-text. Finally, 37 studies were included in qualitative and quantitative analysis. The pooled sensitivity and specificity of ultrasonography for diagnosis of intussusception were 0.96 (95% CI: 0.95-0.97) and 0.97 (95% CI: 0.97-0.98), respectively. The pooled positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 24.57 (95% CI: 8.26-73.03) and 0.05 (95% CI: 0.04-0.08), respectively. The area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.989. Mete-regression showed that there is no significant difference between diagnostic performance of POCUS and RADUS (p = 0.06 and rDOR (diagnostic odds ratio) = 4.38 (95% CI: 0.92-20.89)). Conclusion: This meta-analysis shows that ultrasonography has excellent sensitivity, specificity, and accuracy for diagnosis of intussusception in pediatric patients. Moreover, we found that diagnostic performance of POCUS is similar to that of RADUS for diagnosis of intussusception.

Circular RNAs in neuroblastoma: Pathogenesis, potential biomarker, and therapeutic target.

Neuroblastoma (NB) is a common cancer in childhood responsible for 15 % of fatalities by pediatric cancers. Epigenetic factors play an important role in the pathogenesis of NB. Recently, it has been demonstrated that circular RNAs (circRNAs, ciRNAs), a newly identified class of non-coding RNAs, are also dysregulated in NB. CircRNAs mediate their functions by regulating gene expression mainly through microRNA (miRNA) sponging. The dysregulation (abnormal upregulation or downregulation) of circRNAs is involved in tumorigenesis of a variety of tumors including NB. It seems that the expression of some circRNAs is correlated with NB prognosis and clinical features. CircRNAs might be favorable as a diagnostic/prognostic biomarker and therapeutic target. However, due to the lack of studies, it is difficult to make a conclusion regarding the clinical benefits of circRNAs. In this review, we discussed the circRNAs that experimentally have been proved to be dysregulated in NB tissues and cancer cells.