Immune pathway upregulation and lower genomic instability distinguish EBV-positive nodal T/NK-cell lymphoma from ENKTL and PTCL-NOS

Primary EBV+ nodal T/NK-cell lymphoma (PTCL-EBV) is a poorly understood disease which shows features resembling extranodal NK/T-cell lymphoma (ENKTL) and is currently not recognized as a distinct entity but categorized as a variant of PTCL-NOS. Herein, we analyzed copy-number aberrations (n=77) with focus on global measures of genomic instability (GI) and homologous recombination deficiency (HRD) and performed gene expression (n=84) and EBV miRNA expression profiling (n=24) and targeted mutational analysis (n=16) to further characterize PTCL-EBV in relation to ENKTL and PTCL-NOS. Multivariate analysis revealed a significantly worse outcome of PTCL-EBV compared to PTCL-NOS (P=0.002) but not ENKTL. Remarkably, PTCL-EBV exhibited significantly lower GI and HRD scores compared to ENKTL and PTCL-NOS. Gene Set Enrichment Analysis revealed many immune-related pathways, interferon alpha/gamma response, and IL6_JAK_STAT3 signaling to be significantly upregulated in PTCL-EBV and correlated with lower GI-scores. We also identified NFκB-associated genes, BIRC3, NFκB1 (p50) and CD27, and their proteins to be upregulated in PTCLEBV. PTCL-EBV demonstrated mostly type 2 EBV latency pattern and, strikingly, exhibited downregulated expression of most EBV miRNAs compared to ENKTL and their target genes were also enriched in immune-related pathways. PTCL-EBV also showed frequent mutations of TET2, PIK3CD and STAT3, and are microsatellite stable. Overall, the poor outcome, low genomic instability, upregulation of immune pathways and downregulation of EBV miRNAs are distinctive features of PTCL-EBV. Our data support the consideration of PTCL-EBV as a distinct entity, provide novel insights into the disease pathogenesis and offer potential new therapeutic targets for this tumor.

MicroRNAs as a Suitable Biomarker to Detect the Effects of Long-Term Exposures to Nanomaterials. Studies on TiO2NP and MWCNT

The presence of nanomaterials (NMs) in the environment may represent a serious risk to human health, especially in a scenario of chronic exposure. To evaluate the potential relationship between NM-induced epigenetic alterations and carcinogenesis, the present study analyzed a panel of 33 miRNAs related to the cell transformation process in BEAS-2B cells transformed by TiO2NP and long-term MWCNT exposure. Our battery revealed a large impact on miRNA expression profiling in cells exposed to both NMs. From this analysis, a small set of five miRNAs (miR-23a, miR-25, miR-96, miR-210, and miR-502) were identified as informative biomarkers of the transforming effects induced by NM exposures. The usefulness of this reduced miRNA battery was further validated in other previously generated transformed cell systems by long-term exposure to other NMs (CoNP, ZnONP, MSiNP, and CeO2NP). Interestingly, the five selected miRNAs were consistently overexpressed in all cell lines and NMs tested. These results confirm the suitability of the proposed set of mRNAs to identify the potential transforming ability of NMs. Particular attention should be paid to the epigenome and especially to miRNAs for hazard assessment of NMs, as wells as for the study of the underlying mechanisms of action.

Left-Sided Colorectal Cancer Distinct in Indigenous African Patients Compared to Other Ethnic Groups in South Africa.

Introduction: A large proportion of indigenous African (IA) colorectal cancer (CRC) patients in South Africa are young (<50years), with no unique histopathological or molecular characteristics. Anatomical site as well as microsatellite instability (MSI) status have shown to be associated with different clinicopathological and molecular features. This study aimed to ascertain key histopathological and miRNA expression patterns in microsatellite stable (MSS) and low-frequency MSI (MSI-L) patients, to provide insight into the mechanism of the disease. Methods: A retrospective cohort (2011-2015) of MSS/MSI-L CRC patient samples diagnosed at Charlotte Maxeke Johannesburg Academic Hospital was analyzed. Samples were categorized by site [Right colon cancer (RCC) versus left (LCC)], ethnicity [IA versus other ethnic groups (OEG)] and MSI status (MSI-L vs MSS). T-test, Fischer’s exact and Chi-square tests were conducted. Additional miRNA expression profiling was performed on IA patient samples. Results: IA patients with LCC demonstrated an increased prevalence in males, sigmoid colon, signet-ring-cell morphology, MSI-L with BAT25/26 marker instability and advanced disease association. MiRNA expression profiling revealed unique clustering, with dysregulation of let-7 and miRNA-125. Conclusion: This study revealed distinct histopathological features for LCC, and suggests BAT25/26, miRNAs let-7a-5p and miRNA-125a/b-5p as negative prognostic markers in African CRC patients. Larger confirmatory studies are recommended.

Serum exosomal miRNA from endometriosis patients correlates with disease severity

Purpose Exosomes are vesicles secreted by cells that contain a wide variety of biomolecules, including proteins or nucleic acids. MicroRNAs (miRNAs), which are commonly found in exosomes, are known to play important roles in the pathophysiology of endometriosis. Methods This study investigated the miRNA expression profile of serum exosomes from women with endometriosis in comparison with normal controls as well as the possible role of identified miRNAs in the pathogenesis of endometriosis. Exosomes with a diameter between 60 and 100 nm were identified by their expression of exosomal marker proteins CD9 and CD63. Results Microarray miRNA expression profiling analysis revealed that 26 genes were significantly up-regulated and 19 genes were significantly down-regulated in serum exosomes from endometriosis patients compared with normal controls. These differentially expressed miRNAs were mainly enriched in the regulation of cellular development, metabolism, and involved in the regulation of the MAPK and PI3k-Akt pathways. qRT-PCR analysis verified the differential expression of three miRNAs, miR-26b-5p, miR-215-5p, and miR-6795-3p. Conclusion Further analysis indicated that these differentially expressed miRNAs in serum exosomes may be involved in the pathogenesis of endometriosis and are related to the severity and certain symptoms of endometriosis.

Regulatory Role of microRNAs Targeting the Transcription Co-Factor ZNF521 in Normal Tissues and Cancers

Powerful bioinformatics tools have provided a wealth of novel miRNA–transcription factor networks crucial in controlling gene regulation. In this review, we focus on the biological functions of miRNAs targeting ZNF521, explaining the molecular mechanisms by which the dysregulation of this axis contributes to malignancy. ZNF521 is a stem cell-associated co-transcription factor implicated in the regulation of hematopoietic, neural, and mesenchymal stem cells. The aberrant expression of ZNF521 transcripts, frequently associated with miRNA deregulation, has been detected in several tumors including pancreatic, hepatocellular, gastric, bladder transitional cell carcinomas as well as in breast and ovarian cancers. miRNA expression profiling tools are currently identifying a multitude of miRNAs, involved together with oncogenes and TFs in the regulation of oncogenesis, including ZNF521, which may be candidates for diagnostic and prognostic biomarkers of cancer.

Serum microRNA Expression Profiling in Malaria Patients and Bioinformatic Analysis of Hsa-miR-106b-5p

BackgroundMalaria, caused by Plasmodium, is one of the three major infectious diseases that se­riously endangers public health. Resistance to an­ti-malarial drugs and insecticides has made the prevention and control of malar­ia shown little improvement in the last four years. This study aimed to explore the changes in microRNA (miRNA) expression profiling of malaria patient and predict malaria-related miRNA by bioinformatics methods to provide theoretical basis for further verification of the correlation between specific miRNAs and immune regulation of malaria.MethodsSerum of patients infected by Plasmodium falciparum and healthy people from Myanmar border area was collected. miRNA expression profiling was obtained by RT-qPCR. Then the differentially expressed miRNA was screened and target genes were predicted by four miRNA databases (TargetScan, DIANA-microT, miRDB, and miRTarbase) and an intersection of target genes was obtained by Venn analysis. GO and KEGG analysis were performed for the overlapping target genes via Metascape. The results were further visualized by Cytoscape. Finally, Protein-protein interaction (PPI) network of predicted overlapping target genes was built by STRING.ResultsAmong the 341 tested serum miRNAs, 64 were differentially expressed in malaria patients (P<0.05), 27 miRNAs were up-regulated and 37 miRNAs were down-regulated. The miRNA with the most significant difference was hsa-miR-106b-5p (FC=14.871, adjusted.P.value<0.01); GO and KEGG analysis found that its overlapping predicted target gene set was remarkably enriched in biological functions such as GO:0007264~small GTPase mediated signal transduction, GO:0051056~regulation of small GTPase mediated signal transduction, GO:0051020~GTPase binding, GO:0048514~blood vessel morphogenesis(P<0.01) and signal pathway such as hsa04144: Endocytosis, hsa01521:EGFR tyrosine kinase inhibitor resistance, hsa05212:Pancreatic cancer (P<0.01); Besides, a PPI network containing 39 predicted target genes of hsa-miR-106b-5p was constructed, and 5 hub genes VEGFA, STAT3, RACGAP1, OCRL, and RBBP7 have been selected.ConclusionThe bioinformatics analysis results indicated that hsa-miR-106b-5p has a great relationship with malaria, it plays a part in inhibiting the emergence of ARTs resistance in Plasmodium and tumor progression, which may be achieved by regulating vascular morphogenesis, endocytosis, and VEGFA. The underlying mechanism needs to be further elucidated. We believe that this finding will facilitate an in-depth research on the as­sociation between malaria and miRNA.

A coordinated function of lncRNA HOTTIP and miRNA-196b underpinning leukemogenesis by targeting Fas signaling

MicroRNAs (miRNAs) may modulate more than 60% of human coding genes and act as negative regulators, while long non-coding RNAs (lncRNAs) regulate gene expression on multiple levels by interacting with chromatin, functional proteins, and RNAs such as mRNAs and microRNAs. However, the crosstalk between lncRNA HOTTIP and miRNAs in leukemogenesis remains elusive. Using combined integrated analyses of global miRNA expression profiling and state-of-the-art genomic analyses of chromatin such as ChIRPseq., (genome wide HOTTIP binding analysis), ChIP-seq., and ATACseq., we found that miRNA genes are directly controlled by HOTTIP. Specifically, the HOX cluster miRNAs (miR-196a, miR-196b, miR-10a and miR-10b), located cis & trans, were most dramatically regulated and significantly decreased in HOTTIP knockout (KO) AML cells. HOTTIP bound to the miR-196b promoter, and HOTTIP deletion reduced chromatin accessibility and enrichment of active histone modifications at HOX cluster associated miRNAs in AML cells, while reactivation of HOTTIP restored miR gene expression and chromatin accessibility in the CTCF-boundary-attenuated AML cells. Inactivation of HOTTIP or miR-196b promotes apoptosis by altering the chromatin signature at the FAS promoter and increasing FAS expression. Transplantation of miR-196b knockdown MOLM13 cells in NSG mice increased overall survival compared to wild-type cells. Thus, HOTTIP remodels the chromatin architecture around miRNAs to promote their transcription, consequently repressing tumor suppressors and promoting leukemogenesis.

CRISPR/Cas13-Based Approaches for Ultrasensitive and Specific Detection of microRNAs

MicroRNAs (miRNAs) have a prominent role in virtually every aspect of cell biology. Due to the small size of mature miRNAs, the high degree of similarity between miRNA family members, and the low abundance of miRNAs in body fluids, miRNA expression profiling is technically challenging. Biosensors based on electrochemical detection for nucleic acids are a novel category of inexpensive and very sensitive diagnostic tools. On the other hand, after recognizing the target sequence, specific CRISPR-associated proteins, including orthologues of Cas12, Cas13, and Cas14, exhibit collateral nonspecific catalytic activities that can be employed for specific and ultrasensitive nucleic acid detection from clinically relevant samples. Recently, several platforms have been developed, connecting the benefits of enzyme-assisted signal amplification and enzyme-free amplification biosensing technologies with CRISPR-based approaches for miRNA detection. Together, they provide high sensitivity, precision, and fewer limitations in diagnosis through efficient sensors at a low cost and a simple miniaturized readout. This review provides an overview of several CRISPR-based biosensing platforms that have been developed and successfully applied for ultrasensitive and specific miRNA detection.

Deregulated miRNAs Contribute to Silencing of B-Cell Specific Transcription Factors and Activation of NF-κB in Classical Hodgkin Lymphoma

A hallmark of classical Hodgkin lymphoma (cHL) is the attenuation of B-cell transcription factors leading to global transcriptional reprogramming. The role of miRNAs (microRNAs) involved in this process is poorly studied. Therefore, we performed global miRNA expression profiling using RNA-seq on commonly used cHL cell lines, non-Hodgkin lymphoma cell lines and sorted normal CD77+ germinal centre B-cells as controls and characterized the cHL miRNome (microRNome). Among the 298 miRNAs expressed in cHL, 56 were significantly overexpressed and 23 downregulated (p < 0.05) compared to the controls. Moreover, we identified five miRNAs (hsa-miR-9-5p, hsa-miR-24-3p, hsa-miR-196a-5p, hsa-miR-21-5p, hsa-miR-155-5p) as especially important in the pathogenesis of this lymphoma. Target genes of the overexpressed miRNAs in cHL were significantly enriched (p < 0.05) in gene ontologies related to transcription factor activity. Therefore, we further focused on selected interactions with the SPI1 and ELF1 transcription factors attenuated in cHL and the NF-ĸB inhibitor TNFAIP3. We confirmed the interactions between hsa-miR-27a-5p:SPI1, hsa-miR-330-3p:ELF-1, hsa-miR-450b-5p:ELF-1 and hsa-miR-23a-3p:TNFAIP3, which suggest that overexpression of these miRNAs contributes to silencing of the respective genes. Moreover, by analyzing microdissected HRS cells, we demonstrated that these miRNAs are also overexpressed in primary tumor cells. Therefore, these miRNAs play a role in silencing the B-cell phenotype in cHL.