Integrated whole transcriptome profiling revealed a convoluted circular RNA-based competing endogenous RNAs regulatory network in colorectal cancer.

Recently, it has been identified that circRNAs can act as miRNA sponge to regulate gene expression in various types of cancers, associating them with cancer initiation and progression. The present study aims to identify colorectal cancer-related circRNAs and the underpinning mechanisms of circRNA/miRNA/mRNA networks in the development and progress of Colorectal Cancer. Differentially expressed circRNAs, miRNAs, and mRNAs were identified in GEO microarray datasets using the Limma package of R. The analysis of differentially expressed circRNAs resulted in 23 upregulated and 31 downregulated circRNAs. CeRNAs networks were constructed by intersecting the results of predicted and experimentally validated databases, circbank and miRWalk, and by performing DEMs and DEGs analysis using Cytoscape. Next, functional enrichment analysis was performed for DEGs included in ceRNA networks. Followed by survival analysis, expression profile assessment using TCGA and GEO data, and ROC curve analysis we identified a ceRNA sub-networks that revealed the potential regulatory effect of hsa_circ_0001955 and hsa_circ_0071681 on survival-related genes, namely KLF4, MYC, CCNA2, RACGAP1, and CD44. Overall, we constructed a convoluted regulatory network and outlined its likely mechanisms of action in CRC, which may contribute to the development of more effective approaches for early diagnosis, prognosis, and treatment of CRC.

Mutation Analysis of KRAS and BRAF in Iranian Colorectal Cancer patients: A Novel Variant in Exon 15 of BRAF.

BACKGROUND: Mitogen-Activated Protein Kinase (MAPK) pathway and its downstream signaling pathways, play an important role in intracellular signaling. Mutations in KRAS (activating mutation) and BRAF proto-oncogenes are identified as key finding of colorectal cancer. The aim of this study was to examine mutation analysis of KRAS and BRAF in Iranian Colorectal cancer patients. METHODS: We used fifty archived formalin fixed paraffin-embedded (FFPE) blocks of Iranian colorectal cancer patients. DNA was extracted from FFPE blocks for PCR assay. The quality of PCR products was determined using horizontal electrophoresis. Then, sequencing and analysis of the sequencing results were performed to investigate variation status in the sequences. RESULTS: KRAS exons and BRAF genes exon 15 in 50 CRC patients were analyzed, among the 19 mutant KRAS samples, 18 (36%) patients had a single base substitution (synonymous mutation) in exon 5, p. Arg161Arg (c.483G>A) and 1 (2%) patient in exon 2 (codon 12), p. Gly12Cys (c.34G>T). Also, we observed two mutations p. Val600Glu (c.1799 T>A) and p. Ser616Thr (c.1846T>A) in exon 15 of BRAF gene. CONCLUSIONS: We found a novel variant in BRAF gene. The p. Ser616Thr (c.1846T>A) mutation was not previously reported and we conclude that other new mutations can be identified in KRAS and BRAF which may lead to colorectal cancer.

Promising therapeutic approaches using CRISPR/Cas9 genome editing technology in the treatment of Duchenne muscular dystrophy.

Duchenne muscular dystrophy is an X-linked recessive hereditary monogenic disorder caused by inability to produce dystrophin protein. In most patients, the expression of dystrophin lost due to disrupting mutations in open reading frame. Despite the efforts in a large number of different therapeutic approaches to date, the treatments available for DMD remain mitigative and supportive to improve the symptoms of the disease, rather than to be curative. The advent of CRISPR/Cas9 technology has revolutionized genome editing scope and considered as pioneer in effective genomic engineering. Deletions or excisions of intragenic DNA by CRISPR as well as a similar strategy with exon skipping at the DNA level induced by antisense oligonucleotides, are new and promising approaches in correcting DMD gene, which restore the expression of a truncated but functional dystrophin protein. Also, CRISPR/Cas9 technology can be used to treat DMD by removing duplicated exons, precise correction of causative mutation by HDR-based pathway and inducing the expression of compensatory proteins such as utrophin. In this study, we briefly explained the molecular genetics of DMD and a historical overview of DMD gene therapy. We in particular focused on CRISPR/Cas9-mediated therapeutic approaches that used to treat DMD.

Expression Analysis of Long Non-Coding RNAs Related With FOXM1, GATA3, FOXA1 and ESR1 in Breast Tissues.

Breast cancer is the most common neoplasm among females. Estrogen receptor (ESR) signaling has a prominent impact in the pathogenesis of breast cancer. Among the transcription factors associated with ESR signaling, FOXM1, GATA3, FOXA1 and ESR1 have been suggested as a candidate in the pathogenesis of this neoplasm. In the current project, we have designed an in silico approach to find long non-coding RNAs (lncRNAs) that regulate these transcription factors. Then, we used clinical samples to carry out validation of our in silico findings. Our systems biology method led to the identification of APTR, AC144450.1, linc00663, ZNF337.AS1, and RAMP2.AS1 lncRNAs. Subsequently, we assessed the expression of these genes in breast cancer tissues compared with the adjacent non-cancerous tissues (ANCTs). Expression of GATA3 was significantly higher in breast cancer tissues compared with ANCTs (Ratio of mean expressions (RME) = 4.99, P value = 3.12E-04). Moreover, expression levels of APTR, AC144450.1, and ZNF337.AS1 were elevated in breast cancer tissues compared with control tissues (RME = 2.27, P value = 5.40E-03; Ratio of mean expressions = 615.95, P value = 7.39E-19 and RME = 1.78, P value = 3.40E-02, respectively). On the other hand, the expression of RAMP2.AS1 was lower in breast cancer tissues than controls (RME = 0.31, P value = 1.87E-03). Expression levels of FOXA1, ESR1, and FOXM1 and linc00663 were not significantly different between the two sets of samples. Expression of GATA3 was significantly associated with stage (P value = 4.77E-02). Moreover, expressions of FOXA1 and RAMP2.AS1 were associated with the mitotic rate (P values = 2.18E-02 and 1.77E-02, respectively). Finally, expressions of FOXM1 and ZNF337.AS1 were associated with breastfeeding duration (P values = 3.88E-02 and 4.33E-02, respectively). Based on the area under receiver operating characteristics curves, AC144450.1 had the optimal diagnostic power in differentiating between cancerous and non-cancerous tissues (AUC = 0.95, Sensitivity = 0.90, Specificity = 0.96). The combination of expression levels of all genes slightly increased the diagnostic power (AUC = 0.96). While there were several significant pairwise correlations between expression levels of genes in non-tumoral tissues, the most robust correlation was identified between linc00663 and RAMP2.AS1 (r = 0.61, P value = 3.08E-8). In the breast cancer tissues, the strongest correlations were reported between FOXM1/ZNF337.AS1 and FOXM1/RAMP2.AS1 pairs (r = 0.51, P value = 4.79E-5 and r = 0.51, P value = 6.39E-5, respectively). The current investigation suggests future assessment of the functional role of APTR, AC144450.1 and ZNF337.AS1 in the development of breast neoplasms.

Filaggrin gene polymorphisms in Iranian ichthyosis vulgaris and atopic dermatitis patients.

BACKGROUND: Filaggrin is a key structural epidermal protein in terminal differentiation and formation of skin barrier. The important role of filaggrin and its effects in various cutaneous and noncutaneous disorders initiated a cascade of considerable research in recent years. Loss-of-function mutations in FLG, the human gene encoding profilaggrin/filaggrin, is the cause of the common skin condition ichthyosis vulgaris (IV) and major genetic predisposing factor for atopic dermatitis (AD). Several null mutations in the FLG gene that lead to a decrease or absence of filaggrin in skin and predispose these conditions have been described. OBJECTIVE: The aim of this study was to investigative genetic polymorphism of FLG in Iranian patients with IV and AD. METHODS: In the current study, we carried out full sequencing of the entire FLG coding region in 30 IV patients and 30 AD patients, and also 60 healthy controls. RESULTS: In our research, we identified 43 variants reported previously and two novel variants. CONCLUSION: In our study, in the AD and IV patients, loss-of-function FLG mutation was not found. This means that another mechanism other than FLG nonsense mutation is involved in the pathogenesis of these patients.

Mutation characterization and heterodimer analysis of patients with leukocyte adhesion deficiency: Including one novel mutation.

BACKGROUND AND AIM: Leukocyte adhesion deficiency type 1 (LAD-I) is a rare, autosomal recessive disorder of neutrophil migration, characterized by severe, recurrent bacterial infections, inadequate pus formation and impaired wound healing. The ITGB2 gene encodes the ß2 integrin subunit (CD18) of the leukocyte adhesion cell molecules, and mutations in this gene cause LAD-I. The aim of the current study was to investigate the mutations in patients diagnosed with LAD-I and functional studies of the impact of two previously reported and a novel mutation on the expression of the CD18/CD11a heterodimer. MATERIALS AND METHODS: Blood samples were taken from three patients who had signed the consent form. Genomic DNA was extracted and ITGB2 exons and flanking intronic regions were amplified by polymerase chain reaction. Mutation screening was performed after Sanger sequencing of PCR products. For functional studies, COS-7 cells were co-transfected with an expression vector containing cDNA encoding mutant CD18 proteins and normal CD11a. Flow cytometry analysis of CD18/CD11a expression was assessed by dimer-specific IB4 monoclonal antibody. RESULTS: Two previously reported mutations and one novel mutation,p. Cys562Tyr, were found. All mutations reduced CD18/CD11 heterodimer expression. CONCLUSION: Our strategy recognized the p.Cys562Tyr mutation as a pathogenic alteration that does not support CD18 heterodimer formation. Therefore, it can be put into a panel of carrier and prenatal diagnosis programs.