Differential Expression of lincRNA-ROR Spliced Transcript Variants in Breast Cancer.

Background: We investigated the expression pattern of a human stem cell-specific, large intergenic noncoding RNA (lincRNA) regulator of reprogramming (lincRNA-ROR) and its spliced transcript variants in breast tumors. Breast cancer is the leading cause of cancer mortality in women; therefore, finding a reliable diagnostic tumor marker, based on the molecular profile of tumor cells, is warranted. Methods: qRT-PCR was used to investigate the expression alteration of a specific stem cell-related lincRNA and its spliced transcript variants in breast tumors which provided by the Iran National Tumor Bank (2014-2016). Suitability of lincRNA-ROR and expression alterations of its spliced transcript variants as breast tumor biomarkers were examined by ROC curve analysis. Results: Expression was significantly upregulated in lincRNA-ROR variants 1 (NR-048536) and 4 (AB844432) and downregulated in variant 3 (AB844431), with expression levels failing to distinguish between breast tumor types, grades, and malignancy stages. Whereas ROC curve analysis gave good scores to the expressions of variants 1 (AUC=0.7675, P=0.003) and 3 (AUC=0.9383, P=0.00173), suggesting their suitability as potential breast tumor biomarkers, it gave an AUC score of 0.6033 for lincRNA-ROR spliced variant 4 (P=0.4118), denoting its unsuitability as a breast cancer biomarker. Conclusion: Aberrant expressions of lincRNA-ROR spliced transcript variants could serve as reliable biomarkers with potential usefulness in breast cancer diagnosis. However, further research should elucidate the role and tissue expression of lincRNA-ROR spliced transcript variants in various cancers.

Circular RNAs: New Players in Cardiomyopathy.

Cardiomyopathies comprise a heterogeneous group of cardiac diseases identified by myocardium disorders and diminished cardiac function. They often lead to heart failure or heart transplantation and constitute one of the principal causes of morbidity and mortality worldwide. Circular RNAs (circRNAs) are a novel type of noncoding RNAs. They are covalently closed and single-stranded and derived from the exons and introns of genes by alternative splicing. This specific structure renders them resistant to exonuclease digestion. Many recent studies have demonstrated that circRNAs are highly abundant and conserved and can play central roles in biological functions such as microRNA (miRNA) sponging, splicing, and transcription regulation. Emerging evidence indicates that circRNAs can play significant roles in cardiovascular diseases, including cardiomyopathies. In this review, we briefly describe the current understanding regarding the classification, nomenclature, characteristics, and function of circRNAs and report recent significant findings concerning the roles of circRNAs in cardiomyopathies. Furthermore, we discuss the clinical application potential of circRNAs as the therapeutic targets and diagnostic biomarkers of cardiomyopathies.

Dilated cardiomyopathy caused by a pathogenic nucleotide variant in RBM20 in an Iranian family.

INTRODUCTION: Dilated cardiomyopathy (DCM) is characterized by the dilation and impaired contraction of 1 or both ventricles and can be caused by a variety of disorders. Up to 50% of idiopathic DCM cases have heritable familial diseases, and the clinical screening of family members is recommended. Identifying a genetic cause that can explain the DCM risk in the family can help with better screening planning and clinical decision-making. Whole-exome sequencing (WES) has aided significantly in the detection of causative genes in many genetically heterogeneous diseases. In the present study, we applied WES to identify the causative genetic variant in a family with heritable DCM. METHODS: WES was applied to identify genetic variants on a 26-year-old man as the proband of a family with DCM. Subsequently, Sanger sequencing was performed to confirm the variant in the patient and all the available affected and unaffected family members. The pathogenicity of the variant was evaluated through co-segregation analysis in the family and employment of in silico predictive software. RESULTS: WES demonstrated the missense pathogenic heterozygous nucleotide variant, c.1907G > A, (p.Arg636His, rs267607004, NM_0011343), in exon 9 of the RBM20 gene in the proband. The variant was co-segregated in all the affected family members in a heterozygous form and the unaffected family members. The in silico analysis confirmed the variant as pathogenic. CONCLUSION: Pathogenic RBM20 nucleotide variants are associated with arrhythmogenic DCM. We believe that our report is the first to show an RBM20 variant in Iranian descent associated with DCM.