VEGF Specific siRNAs Act Synergistically with Bortezomib and Steroids in Inhibiting VEGF Gene Expression, Proliferation and Induction of Apoptosis in Multiple Myeloma Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5266-5266
Author(s):  
Michael Koldehoff ◽  
Nina K. Steckel ◽  
Rudolf Trenschel ◽  
Dietrich W. Beelen ◽  
Ahmet H. Elmaagacli
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Gene Silencing ◽  
Antitumor Agents ◽  
Synergistic Effects ◽  
Transcriptional Gene Silencing ◽  
Vegf Gene ◽  
Post Transcriptional Gene Silencing ◽  
Induction Of Apoptosis

Abstract Multiple myeloma (MM) is a clonal B-cell malignancy characterized by the accumulation of malignant plasma cells within the bone marrow (BM). Vascular endothelial growth factor (VEGF), a glycoprotein produced by normal and neoplastic cells is an important regulator of physiological and pathological angiogenesis. MM cells secrete VEGF, which promotes production of cytokines in bone marrow stromal cells, as well as migration and proliferation of the tumor cells. Inhibition of VEGF activity or disabling the function of its receptors has been shown to inhibit both tumor growth and spread of metastases in a variety of animal tumor models. RNA interference (RNAi) is rapidly being established as a post-transcriptional gene silencing method and holds promise to specifically inhibit gene expression in mammals. Another novel class of antitumor agents is based on the inhibition of the ubiquitin-proteosomal system which represents the major nonlysosomal pathway through which intracellular proteins are degraded in eukaryotic cells. Bortezomib, a reversible proteosome inhibitor, shows remarkable anticancer activity in various malignant cell types, including MM cells that are resistant to conventional therapies. We studied the effect of transfection with small interfering RNA (siRNA) targeting VEGF in MM cells in terms of proliferation, induction of apoptosis, and cell differentiation. Further, we evaluated if the effects of post-transcriptional gene silencing by VEGF specific siRNA can be augmented by bortezomib and/or steroids in the cell line OPM-2. A mean reduction of VEGF gene expression to 38% as determined by real-time PCR was observed with 0.8 ug VEGF siRNA in OPM-2 cells compared to controls (controls were set up to 100%). Simultaneous administration of bortezomib and siRNA was able to reduce VEGF gene expression down to 23% compared to VEGF siRNA alone demonstrating a synergistic effect of combined bortezomib and siRNA treatment. We found a 2.5-fold increase in induced apoptosis in OPM-2 cells subsequent to VEGF siRNA administration but we saw no additional stimulation of apoptosis after combination of VEGF siRNA with bortezomib and/or steroids. Proliferation in OPM-2 cells was strongly inhibited (about 91%) following combination treatment as opposed to only 62% after administration of VEGF siRNA alone. The transfection of VEGF siRNA in OPM-2 cells had no influence on the expression levels of differentiation markers such as CD38, CD138, CD19, CD34, CD45, and CD7AAD. Our findings suggest that synergistic effects of VEGF siRNA with bortezomib and dexamethason may offer new therapeutic options in the treatment of MM.

RNA duplexes in transcriptional regulation

2010 ◽  
Vol 1 (3-4) ◽  
pp. 285-296
Author(s):  
Sanjay Swaminathan ◽  
Chantelle L. Hood ◽  
Kazuo Suzuki ◽  
Anthony D. Kelleher
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Gene Silencing ◽  
Gene Activation ◽  
Current Status ◽  
Transcriptional Gene Silencing ◽  
Regulatory Pathways ◽  
Rna Molecules ◽  
Post Transcriptional Gene Silencing ◽  
Rna Duplexes

AbstractTranscriptional regulation by small RNA molecules, including small interfering RNA and microRNA, has emerged as an important gene expression modulator. The regulatory pathways controlling gene expression, post-transcriptional gene silencing and transcriptional gene silencing (TGS) have been demonstrated in yeast, plants and more recently in human cells. In this review, we discuss the currents models of transcriptional regulation and the main components of the RNA-induced silencing complex and RNA-induced transcriptional silencing complex machinery, as well as confounding off-target effects and gene activation. We also discuss RNA-mediated TGS within the NF-κB motif of the human immunodeficiency virus type 1 5′ long tandem repeat promoter region and the associated epigenetic modifications. Finally, we outline the current RNA interference (RNAi) delivery methods and describe the current status of human trials investigating potential RNAi therapeutics for several human diseases.

scholarly journals small RNA can move long distances through plant vasculature to influence gene expression in shoot apical meristems

2021 ◽  
Author(s):  
Mark A. A. Minow ◽  
Viktoriya Coneva ◽  
Victoria Lesy ◽  
Max Misyura ◽  
Joseph Colasanti
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Gene Silencing ◽  
Small Rna ◽  
Separate Experiment ◽  
Transcriptional Gene Silencing ◽  
Long Distance ◽  
Regulate Gene Expression ◽  
Post Transcriptional Gene Silencing ◽  
Influence Gene Expression

AbstractIn plants, small RNA (sRNA) can regulate gene expression via post transcriptional gene silencing (PTGS) or through RNA-directed DNA methylation (RdDM) leading to transcriptional gene silencing (TGS). sRNA is mobile throughout the plant, with movement occurring short distances from cell-to-cell as well as long distances through the vasculature via phloem trafficking. The range of long-distance sRNA mediated signaling from the vasculature to the shoot apical meristem (SAM) is not clear. To investigate this, two independent transgenic approaches were used to examine trafficking of phloem-expressed sRNA to the SAM in Arabidopsis thaliana. First, the phloem companion-cell specific promoter SUC2 was used to drive expression of an inverted repeat complementary to FLOWERING LOCUS D (FD), a flowering time regulator expressed exclusively in the SAM. In a separate experiment, the SUC2 promoter was used to express an artificial microRNA (aMiR) designed to target a synthetic CLAVATA3 (CLV3) target in the SAM stem cells. Both systems provide evidence of a phloem-to-SAM sRNA communication axis connecting distal regions of the plant to the stem cells of the SAM, which ultimately gives rise to all shoot tissues, including gametes. Thus, phloem-to-SAM sRNA movement defines an important link between sRNA expressed in distal regions of the plant and the growing shoot. Importantly, phloem-to-SAM sRNA trafficking may allow somatic sRNA to direct SAM RdDM, fixing transient sRNA expression events into stable epigenetic changes.

scholarly journals Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1187
Author(s):  
Michael Wassenegger ◽  
Athanasios Dalakouras
Keyword(s):  
Dna Methylation ◽  
Rna Interference ◽  
Gene Silencing ◽  
Plant Cells ◽  
Transcriptional Gene Silencing ◽  
Rnai Machinery ◽  
Double Stranded Rna ◽  
Post Transcriptional Gene Silencing ◽  
Cumulative Amount

Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.

scholarly journals Epigenetic Changes in Host Ribosomal DNA Promoter Induced by an Asymptomatic Plant Virus Infection

Biology ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 91 ◽  
Author(s):  
Miryam Pérez-Cañamás ◽  
Elizabeth Hevia ◽  
Carmen Hernández
Keyword(s):  
Gene Silencing ◽  
Ribosomal Dna ◽  
Plant Virus ◽  
Dna Methyltransferase ◽  
Cytosine Methylation ◽  
De Novo ◽  
Methylation Pattern ◽  
Transcriptional Gene Silencing ◽  
Post Transcriptional Gene Silencing ◽  
The Impact

DNA cytosine methylation is one of the main epigenetic mechanisms in higher eukaryotes and is considered to play a key role in transcriptional gene silencing. In plants, cytosine methylation can occur in all sequence contexts (CG, CHG, and CHH), and its levels are controlled by multiple pathways, including de novo methylation, maintenance methylation, and demethylation. Modulation of DNA methylation represents a potentially robust mechanism to adjust gene expression following exposure to different stresses. However, the potential involvement of epigenetics in plant-virus interactions has been scarcely explored, especially with regard to RNA viruses. Here, we studied the impact of a symptomless viral infection on the epigenetic status of the host genome. We focused our attention on the interaction between Nicotiana benthamiana and Pelargonium line pattern virus (PLPV, family Tombusviridae), and analyzed cytosine methylation in the repetitive genomic element corresponding to ribosomal DNA (rDNA). Through a combination of bisulfite sequencing and RT-qPCR, we obtained data showing that PLPV infection gives rise to a reduction in methylation at CG sites of the rDNA promoter. Such a reduction correlated with an increase and decrease, respectively, in the expression levels of some key demethylases and of MET1, the DNA methyltransferase responsible for the maintenance of CG methylation. Hypomethylation of rDNA promoter was associated with a five-fold augmentation of rRNA precursor levels. The PLPV protein p37, reported as a suppressor of post-transcriptional gene silencing, did not lead to the same effects when expressed alone and, thus, it is unlikely to act as suppressor of transcriptional gene silencing. Collectively, the results suggest that PLPV infection as a whole is able to modulate host transcriptional activity through changes in the cytosine methylation pattern arising from misregulation of methyltransferases/demethylases balance.

scholarly journals Prognostic significance of esterase gene expression in multiple myeloma

2021 ◽  
Author(s):  
Romika Kumari ◽  
Muntasir Mamun Majumder ◽  
Juha Lievonen ◽  
Raija Silvennoinen ◽  
Pekka Anttila ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Prognostic Markers ◽  
Prognostic Significance ◽  
Genomic Variation ◽  
High Expression ◽  
Genetic Profile ◽  
Esterase Gene ◽  
Low Expression

Abstract Background Esterase enzymes differ in substrate specificity and biological function and may display dysregulated expression in cancer. This study evaluated the biological significance of esterase expression in multiple myeloma (MM). Methods For gene expression profiling and evaluation of genomic variants in the Institute for Molecular Medicine Finland (FIMM) cohort, bone marrow aspirates were obtained from patients with newly diagnosed MM (NDMM) or relapsed/refractory MM (RRMM). CD138+ plasma cells were enriched and used for RNA sequencing and analysis, and to evaluate genomic variation. The Multiple Myeloma Research Foundation (MMRF) Relating Clinical Outcomes in MM to Personal Assessment of Genetic Profile (CoMMpass) dataset was used for validation of the findings from FIMM. Results MM patients (NDMM, n = 56; RRMM, n = 78) provided 171 bone marrow aspirates (NDMM, n = 56; RRMM, n = 115). Specific esterases exhibited relatively high or low expression in MM, and expression of specific esterases (UCHL5, SIAE, ESD, PAFAH1B3, PNPLA4 and PON1) was significantly altered on progression from NDMM to RRMM. High expression of OVCA2, PAFAH1B3, SIAE and USP4, and low expression of PCED1B, were identified as poor prognostic markers (P < 0.05). The MMRF CoMMpass dataset provided validation that higher expression of PAFAH1B3 and SIAE, and lower expression of PCED1B, were associated with poor prognosis. Conclusions Esterase gene expression levels change as patients progress from NDMM to RRMM. High expression of OVCA2, PAFAH1B3, USP4 and SIAE, and low expression of PCED1B, are poor prognostic markers in MM, suggesting a role for these esterases in myeloma biology.

scholarly journals An atypical class of non-coding small RNAs produced in rice leaves upon bacterial infection

2021 ◽  
Author(s):  
Ganna Reshetnyak ◽  
Jonathan M. Jacobs ◽  
Florence Auguy ◽  
Coline Sciallano ◽  
Lisa Claude ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Stress Responses ◽  
Small Rnas ◽  
Early Stage ◽  
Kinase Domain ◽  
Transcriptional Gene Silencing ◽  
Small Interfering Rnas ◽  
Post Transcriptional Gene Silencing ◽  
Virulent Strains ◽  
Microbe Interactions

ABSTRACTNon-coding small RNAs (sRNA) act as mediators of gene silencing and regulate plant growth, development and stress responses. Early insights into plant sRNAs established a role in antiviral defense and they are now extensively studied across plant-microbe interactions. Here, sRNA sequencing discovered a class of sRNA in rice (Oryza sativa) specifically associated with foliar diseases caused by Xanthomonas oryzae bacteria. Xanthomonas-induced small RNAs (xisRNAs) loci were distinctively upregulated in response to diverse virulent strains at an early stage of infection producing a single duplex of 20-22nt sRNAs. xisRNAs production was dependent on the Type III secretion system, a major bacterial virulence factor for host colonization. xisRNA loci overlap with annotated transcripts sequences often encoding protein kinase domain proteins. A number of the corresponding rice cis-genes have documented functions in immune signaling and some xisRNA loci coincide with the coding sequence of a conserved kinase motif. xisRNAs exhibit features of small interfering RNAs and their biosynthesis depend on canonical components OsDCL1 and OsHEN1. xisRNA induction possibly mediates post-transcriptional gene silencing but they do not broadly suppress cis-genes expression on the basis of mRNA-seq data. Overall, our results identify a group of unusual sRNAs with a potential role in plant-microbe interactions.

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