The critical role and functional mechanism of microRNA-146a in doxorubicin-induced apoptosis in breast cancer cells.

BACKGROUND: Breast cancer among women is the most frequently diagnosed cancer and the leading cause of death worldwide. There many advances in diagnosing and treating this disease, early diagnosis and treatment are still a significant challenge in the early stages. In recent years, microRNAs have attracted much attention in cancer diagnosis and treatment. However, the role of miR-146a in breast cancer is still controversial. We aimed to investigate the roles of miR-146a in apoptosis in breast cancer cells. METHODS: A microarray dataset from the GEO database was selected, and using the GEO2R tool, the gene expression profile of this dataset was extracted. Then, the target scan database was used to explore the miR-146a target genes. The link between the signaling pathways was collected. We used miR-146a mimic, which was transfected to the MCF-7 cells to investigate the miR-146a roles in the apoptosis. The expression levels of miR-146a and BAX, BCL-2, and p-21(most essential genes in the apoptosis) were quantified by qPCR and western blot analysis. RESULTS: Our findings indicated that doxorubicin induces miR-146a expression. In addition, overexpression of miR-146a affected MCF-7 cell viability, induced apoptosis, and led to reduced expression levels of BCL-2 and P-21, as well as increased BAX expression levels. CONCLUSION: Considering the role of doxorubicin in inducing apoptosis and increasing the expression of miR-146a, it can be suggested that this miR is involved in inducing apoptosis in BC cells. In addition, miR-146a can be considered a therapeutic candidate.

A novel missense variant in EIF2B5 identified in a consanguineous Iranian family with vanishing white matter disease and a brief review of the literature.

Vanishing of white matter (VWM) is a hereditary heterogeneous brain disorder that most often affects children. However, the onset of the disease varies from childhood to adulthood. VWM is caused by mutations in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. In the current study, we aimed to determine the genetic cause of VWM in a large consanguineous Iranian family with three affected members. Next-generation sequencing was conducted on the proband to determine the underlying cause of VWM. The identified variant was validated by PCR-Sanger sequencing in the patient and was also segregated in his parents and two other affected members of the pedigree. The potential functional effects of this mutation within EIF2B5 were predicted by in silico analysis. We have also reviewed all EIF2B5 disease-causing variants and available clinical features of each patient reported in HGMD Professional 2022.2. A novel homozygous variant c.746T>G [p.Ile249Ser] was detected in EIF2B5 which was co-segregated with the disease in all affected family members in an autosomal recessive manner. All employed in silico prediction tools and 3D structure analysis for the novel mutation also supported the pathogenicity of this variant. Our study not only expanded the spectrum of the pathogenic variants in EIF2B5 but also presented a literature review on EIF2B5-related conditions that provide a comprehensive picture of the genetic nature of this gene and phenotypic variability in patients.

Whole-Exome Sequencing Identified a Novel Variant (C.405_422+39del) in DSP Gene in an Iranian Pedigree with Familial Dilated Cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is a progressive heart condition characterized by left ventricular chamber enlargement associated with systolic heart failure and prolonged action potential duration. Genetic variations in genes that encode cytoskeleton, sarcomere, and nuclear envelope proteins are responsible for 45% of cases. In our study, we focused on a pedigree with familial DCM to decipher the potential genetic cause(s) in affected members developing arrhythmia, end-stage heart failure, and sudden death. METHODS: Whole-exome sequencing (WES) was exploited for a 27-year-old heart-transplanted female as the proband, and the derived data were filtered using the standard pipelines. RESULTS: A 57-nucleotide deletion (c.405_422+39del) in the desmoplakin gene (DSP) (NM_004415.4) was identified as a novel pathogenic variant. Familial segregation analysis indicated that this variant is present in clinically affected members and absent in unaffected members. CONCLUSION: It seems that the detected variant induces intron retention, resulting in a premature stop codon in intron 3 of DSP leading to production of a truncated, nonfunctional protein. Additionally, it can trigger a nonsense-mediated mRNA decay pathway associated with inhibition of protein production. The present study results illustrated that a novel deletion in DSP can cause DCM in an Iranian family.

Circulating microRNAs as diagnostic and therapeutic biomarkers in gastric and esophageal cancers.

Gastric and esophageal cancers are as main cancers of the gastrointestinal (GI) tract, which are associated with poor diagnosis and survival. Several efforts were made in the past few decades to finding effective therapeutic approaches, but these approaches had several problems. Finding new biomarkers is a critical step in finding new approaches for the treatment of these cancers. Finding new biomarkers that cover various aspects of the diseases could provide a choice of suitable therapies and better monitoring of patients with these cancers. Among several biomarkers tissue specific and circulating microRNAs (miRNAs) have emerged as powerful candidates in the diagnosis of gastric and esophageal cancers. MiRNAs are small noncoding single-stranded RNA molecules that are found in the blood and regulate gene expression. These have numerous characteristics that make them suitable for being used as ideal biomarkers in cancer diagnosis. Research has indicated that the level and profile of miRNA in serum and plasma are very high. They are potentially noninvasive and sensitive enough to detect tumors in their primary stages of infection. Multiple lines of evidence indicate that the presence, absence, or deregulation of several circulating miRNAs (i.e., let-7a, miR-21, miR-93, miR-192a, miR-18a, and miR-10b for gastric cancer, and miR-21, miR-375, miR-25-3p, miR-151a-3p, and miR-100-3p for esophageal cancer) are associated with initiation and progression of gastric and esophageal cancers. The aim of this review is to highlight the recent advances in the roles of miRNAs in diagnosis and treatment of gastric and esophageal cancers.