scholarly journals KSHV-Encoded MicroRNAs: Lessons for Viral Cancer Pathogenesis and Emerging Concepts

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Zhiqiang Qin ◽  
Andrew Jakymiw ◽  
Victoria Findlay ◽  
Chris Parsons

The human genome contains microRNAs (miRNAs), small noncoding RNAs that orchestrate a number of physiologic processes through regulation of gene expression. Burgeoning evidence suggests that dysregulation of miRNAs may promote disease progression and cancer pathogenesis. Virus-encoded miRNAs, exhibiting unique molecular signatures and functions, have been increasingly recognized as contributors to viral cancer pathogenesis. A large segment of the existing knowledge in this area has been generated through characterization of miRNAs encoded by the human gamma-herpesviruses, including the Kaposi’s sarcoma-associated herpesvirus (KSHV). Recent studies focusing on KSHV miRNAs have led to a better understanding of viral miRNA expression in human tumors, the identification of novel pathologic check points regulated by viral miRNAs, and new insights for viral miRNA interactions with cellular (“human”) miRNAs. Elucidating the functional effects of inhibiting KSHV miRNAs has also provided a foundation for further translational efforts and consideration of clinical applications. This paper summarizes recent literature outlining mechanisms for KSHV miRNA regulation of cellular function and cancer-associated pathogenesis, as well as implications for interactions between KSHV and human miRNAs that may facilitate cancer progression. Finally, insights are offered for the clinical feasibility of targeting miRNAs as a therapeutic approach for viral cancers.

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Baiba Krivmane ◽  
Ilze Šņepste ◽  
Vilnis Šķipars ◽  
Igor Yakovlev ◽  
Carl Gunnar Fossdal ◽  
...  

MicroRNAs (miRNAs) are non-protein coding RNAs of ~20–24 nucleotides in length that play an important role in many biological and metabolic processes, including the regulation of gene expression, plant growth and developmental processes, as well as responses to stress and pathogens. The aim of this study was to identify and characterize novel and conserved microRNAs expressed in methyl jasmonate-treated Scots pine needles. In addition, potential precursor sequences and target genes of the identified miRNAs were determined by alignment to the Pinus unigene set. Potential precursor sequences were identified using the miRAtool, conserved miRNA precursors were also tested for the ability to form the required stem-loop structure, and the minimal folding free energy indexes were calculated. By comparison with miRBase, 4975 annotated sequences were identified and assigned to 173 miRNA groups, belonging to a total of 60 conserved miRNA families. A total of 1029 potential novel miRNAs, grouped into 34 families were found, and 46 predicted precursor sequences were identified. A total of 136 potential target genes targeted by 28 families were identified. The majority of previously reported highly conserved plant miRNAs were identified in this study, as well as some conserved miRNAs previously reported to be monocot specific. No conserved dicot-specific miRNAs were identified. A number of potential gymnosperm or conifer specific miRNAs were found, shared among a range of conifer species.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chantriolnt-Andreas Kapourani ◽  
Ricard Argelaguet ◽  
Guido Sanguinetti ◽  
Catalina A. Vallejos

AbstractHigh-throughput single-cell measurements of DNA methylomes can quantify methylation heterogeneity and uncover its role in gene regulation. However, technical limitations and sparse coverage can preclude this task. scMET is a hierarchical Bayesian model which overcomes sparsity, sharing information across cells and genomic features to robustly quantify genuine biological heterogeneity. scMET can identify highly variable features that drive epigenetic heterogeneity, and perform differential methylation and variability analyses. We illustrate how scMET facilitates the characterization of epigenetically distinct cell populations and how it enables the formulation of novel hypotheses on the epigenetic regulation of gene expression. scMET is available at https://github.com/andreaskapou/scMET.


Author(s):  
Yue Zhao ◽  
Yuxia Liu ◽  
Shuang Li ◽  
Zhaoyun Peng ◽  
Xiantao Liu ◽  
...  

Abstract Background Lung cancer is the leading cause of cancer-related deaths worldwide (Ferlay et al., Int J Cancer 136:E359–386, 2015). In addition, lung cancer is associated with the highest mortality among all cancer types (Wu et al., Exp Ther Med 16:3004–3010, 2018). Previous studies report that microbiota play an important role in lung cancer. Notably, changes in lung and gut microbiota, are associated with progression of lung cancer. Several studies report that lung and gut microbiome promote lung cancer initiation and development by modulating metabolic pathways, inhibiting the function of immune cells, and producing pro-inflammatory factors. In addition, some factors such as microbiota dysbiosis, affect production of bacteriotoxins, genotoxicity and virulence effect, therefore, they play a key role in cancer progression. These findings imply that lung and gut microbiome are potential markers and targets for lung cancer. However, the role of microbiota in development and progression of lung cancer has not been fully explored. Purpose The aim of this study was to systemically review recent research findings on relationship of lung and gut microbiota with lung cancer. In addition, we explored gut–lung axis and potential mechanisms of lung and gut microbiota in modulating lung cancer progression. Conclusion Pulmonary and intestinal flora influence the occurrence, development, treatment and prognosis of lung cancer, and will provide novel strategies for prevention, diagnosis, and treatment of lung cancer.


NAR Cancer ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Keisuke Katsushima ◽  
George Jallo ◽  
Charles G Eberhart ◽  
Ranjan J Perera

Abstract Long non-coding RNAs (lncRNAs) have been found to be central players in the epigenetic, transcriptional and post-transcriptional regulation of gene expression. There is an accumulation of evidence on newly discovered lncRNAs, their molecular interactions and their roles in the development and progression of human brain tumors. LncRNAs can have either tumor suppressive or oncogenic functions in different brain cancers, making them attractive therapeutic targets and biomarkers for personalized therapy and precision diagnostics. Here, we summarize the current state of knowledge of the lncRNAs that have been implicated in brain cancer pathogenesis, particularly in gliomas and medulloblastomas. We discuss their epigenetic regulation as well as the prospects of using lncRNAs as diagnostic biomarkers and therapeutic targets in patients with brain tumors.


1997 ◽  
Vol 61 (3) ◽  
pp. 294-304
Author(s):  
H D Luján ◽  
M R Mowatt ◽  
T E Nash

Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the life cycles of protozoan and helminthic parasites are excellent models with which to study numerous mechanisms involved in cell differentiation, such as the regulation of gene expression, signal transduction pathways, and organelle biogenesis. Unfortunately, many of these studies are very difficult because the conditions needed to elicit developmental changes in parasites remain undetermined in most cases. Recently, several interesting findings were reported on the process of differentiation of Giardia lamblia trophozoites into cysts. G. lamblia is a flagellated protozoan that inhabits the upper small intestine of its vertebrate host and is a major cause of enteric disease worldwide. It belongs to the earliest identified lineage among eukaryotes and therefore offers a unique insight into the progression from primitive to more complex eukaryotic cells. The discovery of a specific stimulus that induces trophozoites to differentiate into cysts, the identification and characterization of encystation-specific molecules, the elucidation of novel biochemical pathways, and the development of useful reagents and techniques have made this parasite an excellent model with which to study differentiation in eukaryotic cells. In this review, we summarize the most recent fundings on several aspects of Giardia differentiation and discuss the significance of these findings within the context of current knowledge in the field.


2021 ◽  
Author(s):  
Syed N Shah

Histones H3/H4 are deposited onto DNA in a replication-dependent or independent fashion by the CAF1 and HIRA protein complexes. Despite the identification of these protein complexes, mechanistic details remain unclear. Recently, we showed that in T. thermophila histone chaperones Nrp1, Asf1 and the Impβ6 importin function together to transport newly synthesized H3/H4 from the cytoplasm to the nucleus. To characterize chromatin assembly proteins in T.thermophila, I used affinity purification combined with mass spectrometry to identify protein-protein interactions of Nrp1, Cac2 subunit of CAF1, HIRA and histone modifying Hat1-complex in T. thermophila. I found that the three-subunit T.thermophila CAF1 complex interacts with Casein Kinase 2 (CKII), possibly accounting for previously reported human CAF1phosphorylation. I also found that Hat2 subunit of HAT1 complex is also shared by CAF1 complex as its Cac3 subunit. This suggests that Hat2/Cac3 might exist in two separate pools of protein complexes. Remarkably, proteomic analysis of Hat2/Cac3 in turn revealed that it forms several complexes with other proteins including SIN3, RXT3, LIN9 and TESMIN, all of which have known roles in the regulation of gene expression. Finally, I asked how selective forces might have impacted on the function of proteins involved in H3/H4 transport. Focusing on NASP which possesses several TPR motifs, I showed that its protein-protein interactions are conserved in T. thermophila. Using molecular evolutionary methods I show that different TPRs in NASP evolve at different rates possibly accounting for the functional diversity observed among different family members.


Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4471
Author(s):  
Niccolò Roda ◽  
Giada Blandano ◽  
Pier Giuseppe Pelicci

Cancer cells continuously interact with the tumor microenvironment (TME), a heterogeneous milieu that surrounds the tumor mass and impinges on its phenotype. Among the components of the TME, blood vessels and peripheral nerves have been extensively studied in recent years for their prominent role in tumor development from tumor initiation. Cancer cells were shown to actively promote their own vascularization and innervation through the processes of angiogenesis and axonogenesis. Indeed, sprouting vessels and axons deliver several factors needed by cancer cells to survive and proliferate, including nutrients, oxygen, and growth signals, to the expanding tumor mass. Nerves and vessels are also fundamental for the process of metastatic spreading, as they provide both the pro-metastatic signals to the tumor and the scaffold through which cancer cells can reach distant organs. Not surprisingly, continuously growing attention is devoted to the development of therapies specifically targeting these structures, with promising initial results. In this review, we summarize the latest evidence that supports the importance of blood vessels and peripheral nerves in cancer pathogenesis, therapy resistance, and innovative treatments.


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