scholarly journals Posttranscriptional Regulation of the Human ABCG2 Multidrug Transporter Protein by Artificial Mirtrons

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1068
Author(s):  
Anita Schamberger ◽  
György Várady ◽  
Ábel Fóthi ◽  
Tamás I. Orbán
Keyword(s):  
Protein Level ◽  
Posttranscriptional Regulation ◽  
Tumor Development ◽  
Luciferase Reporter ◽  
Seed Region ◽  
Nucleotide Polymorphisms ◽  
Cellular Protection ◽  
Transporter Protein ◽  
Functional Features ◽  
Abcg2 Protein

ABCG2 is a membrane transporter protein that has been associated with multidrug resistance phenotype and tumor development. Additionally, it is expressed in various stem cells, providing cellular protection against endobiotics and xenobiotics. In this study, we designed artificial mirtrons to regulate ABCG2 expression posttranscriptionally. Applying EGFP as a host gene, we could achieve efficient silencing not only in luciferase reporter systems but also at the ABCG2 protein level. Moreover, we observed important new sequential-functional features of the designed mirtrons. Mismatch at the first position of the mirtron-derived small RNA resulted in better silencing than full complementarity, while the investigated middle and 3′ mismatches did not enhance silencing. These latter small RNAs operated most probably via non-seed specific translational inhibition in luciferase assays. Additionally, we found that a mismatch in the first position has not, but a second mismatch in the third position has abolished target mRNA decay. Besides, one nucleotide mismatch in the seed region did not impair efficient silencing at the protein level, providing the possibility to silence targets carrying single nucleotide polymorphisms or mutations. Taken together, we believe that apart from establishing an efficient ABCG2 silencing system, our designing pipeline and results on sequential-functional features are beneficial for developing artificial mirtrons for other targets.

scholarly journals Epigenetic Regulation of MicroRNA Clusters and Families during Tumor Development

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1333
Author(s):  
Jana Gregorova ◽  
Petra Vychytilova-Faltejskova ◽  
Sabina Sevcikova
Keyword(s):  
Histone Modifications ◽  
Sequence Similarity ◽  
Tumor Development ◽  
Hematologic Malignancies ◽  
Seed Region ◽  
Cancer Therapies ◽  
Rna Molecules ◽  
Physiological Processes ◽  
Close Relationship ◽  
Aberrant Dna Methylation

MicroRNAs are small non-coding single-stranded RNA molecules regulating gene expression on a posttranscriptional level based on the seed sequence similarity. They are frequently clustered; thus, they are either simultaneously transcribed into a single polycistronic transcript or they may be transcribed independently. Importantly, microRNA families that contain the same seed region and thus target related signaling proteins, may be localized in one or more clusters, which are in a close relationship. MicroRNAs are involved in basic physiological processes, and their deregulation is associated with the origin of various pathologies, including solid tumors or hematologic malignancies. Recently, the interplay between the expression of microRNA clusters and families and epigenetic machinery was described, indicating aberrant DNA methylation or histone modifications as major mechanisms responsible for microRNA deregulation during cancerogenesis. In this review, the most studied microRNA clusters and families affected by hyper- or hypomethylation as well as by histone modifications are presented with the focus on particular mechanisms. Finally, the diagnostic and prognostic potential of microRNA clusters and families is discussed together with technologies currently used for epigenetic-based cancer therapies.

scholarly journals Rs56288038 (C/G) in 3'UTR of IRF-1 Regulated by MiR-502-5p Promotes Gastric Cancer Development

2016 ◽  
Vol 40 (1-2) ◽  
pp. 391-399 ◽  
Author(s):  
Bo Wang ◽  
Huan Yang ◽  
Liqin Shen ◽  
Ji Wang ◽  
Wangyang Pu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Survival Rate ◽  
Target Genes ◽  
Diagnostic Value ◽  
Tumor Promoter ◽  
Luciferase Reporter ◽  
Nucleotide Polymorphisms ◽  
Susceptible Population ◽  
Poor Differentiation ◽  
Regulatory Capacity

Background/Aims: Interferon regulatory factor 1 (IRF-1) has been shown to function as a transcriptional activator or repressor of a variety of target genes. However, its upstream, non-coding RNA-related regulatory capacity remains unknown. In this study, we focus on the miRNA-associated single nucleotide polymorphisms (SNPs) in the 3′untranslated region (UTR) of IRF-1 to further investigate the functional relationship and potential diagnostic value of the SNPs and miRNAs among Chinese gastric cancer (GC) patients. Methods: We performed a case-control study with 819 GC patients and 756 cancer-free controls. Genotyping by realtime PCR assay, cell transfection, and the dual luciferase reporter assay were used in our study, and the 5-year overall survival rate and relapse-free survival rate in different groups were investigated. Results: We found that patients suffering from Helicobacter pylori (Hp) infection were the susceptible population compared to controls. SNP rs56288038 (C/G) in IRF-1 3′UTR was involved in the occurrence of GC by acting as a tumor promoter factor. SNP rs56288038 (C/G) could be up-regulated by miR-502-5p, which caused a down-regulation of IRF-1 in cell lines and decreased apoptosis induced by IFN-γ. Carrying the G genotype was related to significantly low expression of IRF-1 and Hp infection, poor differentiation, big tumor size, invasion depth, as well as the high probability of metastasis, and moreover, the C/G SNP was associated with shorter survival of GC patients with five years of follow-up study. Conclusions: our findings have shown that the SNP rs56288038 (C/G) in IRF-1 3′UTR acted as a promotion factor in GC development through enhancing the regulatory role of miR-502-5p in IRF-1 expression.

MicroRNAs in domestic livestock

2013 ◽  
Vol 45 (16) ◽  
pp. 685-696 ◽  
Author(s):  
Attia Fatima ◽  
Dermot G. Morris
Keyword(s):  
Posttranscriptional Regulation ◽  
Noncoding Rna ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Small Noncoding Rna ◽  
Domestic Livestock ◽  
Temporal Expression Pattern ◽  
Mrna Binding

microRNAs (miRNAs) are a class of small noncoding RNA that bind to complementary sequences in the untranslated regions of multiple target mRNAs resulting in posttranscriptional regulation of gene expression. The recent discovery and expression-profiling studies of miRNAs in domestic livestock have revealed both their tissue-specific and temporal expression pattern. In addition, breed-dependent expression patterns as well as single nucleotide polymorphisms in either the miRNA or in the target mRNA binding site have revealed associations with traits of economic importance and highlight the potential use of miRNAs in future genomic selection programs.

scholarly journals Nucleolin Promotes Cisplatin Resistance in Cervical Cancer by the YB1-MDR1 Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jing Ke ◽  
Chunming Gu ◽  
Heyan Zhang ◽  
Yang Liu ◽  
Wenhao Zhang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Drug Resistance ◽  
Hela Cells ◽  
Protein Level ◽  
Molecular Mechanisms ◽  
Cisplatin Resistance ◽  
Mdr1 Gene ◽  
Luciferase Reporter ◽  
Drug Efflux ◽  
Cell Line Hela

Purpose. Cervical cancer is the fourth most common cancer in women worldwide and is the main cause of cancer-related deaths in women. Cisplatin (DDP) is one of the major chemotherapeutic drugs for cervical cancer patients. But, drug resistance limits the effectiveness of cancer therapy. Nucleolin (NCL) is a nucleocytoplasmic multifunctional protein involved in the development of cancer. It has been reported that NCL may be a potential target for modulation of drug resistance. However, the precise molecular mechanisms are poorly understood. Materials and Methods. Human cervical cancer Hela cells and their cisplatin-resistant cell line Hela/DDP were used in this study. The protein level of NCL in cervical cancer cells was measured by western blot analysis. Hela cells and Hela/DDP cells were transfected with NCL overexpression plasmid or NCL siRNA separately. MTT and EdU assay were performed to evaluate the cell viability and sensitivity to cisplatin. The drug efflux function of MDR1 protein was assessed by intracellular rhodamine-123 accumulation assay.The promoter activity of MDR1 was assessed by using a dual-luciferase reporter assay. Results. We found that the protein level of NCL was elevated in Hela/DDP cells. Overexpression of NCL increased cervical cancer cell proliferation and attenuated the sensitivity to cisplatin. Overexpression of NCL increased Multidrug resistance (MDR1) gene expression and drug efflux. Our results demonstrated that NCL was highly related with cisplatin resistance in cervical cancer. NCL played an important role in MDR1 gene transcription through regulation of the transcription factor YB1. Conclusion. Our findings revealed the novel role of NCL in cisplatin-resistant cervical cancer and NCL may be a potential therapeutic target for chemoresistance.

scholarly journals MicroRNA-346-5p Regulates Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells by Inhibiting Transmembrane Protein 9

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yicai Zhang ◽  
Yi Sun ◽  
Jinlong Liu ◽  
Yu Han ◽  
Jinglong Yan
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Protein Level ◽  
Molecular Mechanisms ◽  
Transmembrane Protein ◽  
Luciferase Reporter ◽  
Alizarin Red ◽  
Protein Levels

The molecular mechanisms how bone marrow-derived mesenchymal stem cells (BMSCs) differentiate into osteoblast need to be investigated. MicroRNAs (miRNAs) contribute to the osteogenic differentiation of BMSCs. However, the effect of miR-346-5p on osteogenic differentiation of BMSCs is not clear. This study is aimed at elucidating the underlying mechanism by which miR-346-5p regulates osteogenic differentiation of human BMSCs. Results of alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining indicated that upregulation of miR-346-5p suppressed osteogenic differentiation of BMSCs, whereas downregulation of miR-346-5p enhanced this process. The protein levels of the osteoblastic markers Osterix and Runt-related transcription factor 2 (Runx2) were decreased in cells treated with miR-346-5p mimic at day 7 and day 14 after being differentiated. By contrast, downregulation of miR-346-5p elevated the protein levels of Osterix and Runx2. Moreover, a dual-luciferase reporter assay revealed that Transmembrane Protein 9 (TMEM9) was a target of miR-346-5p. In addition, the Western Blot results demonstrated that the TMEM9 protein level was significantly reduced by the miR-346-5p mimic whereas downregulation of miR-346-5p improved the protein level of TMEM9. These results together demonstrated that miR-346-5p served a key role in BMSC osteogenic differentiation of through targeting TMEM9, which may provide a novel target for clinical treatments of bone injury.

Identification and Effects of Novel Promoter Region Haplotypes in the Human Equilibrative Nucleoside Transporter, hENT1.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2083-2083
Author(s):  
Scott N. Myers ◽  
Rakesh K. Goyal ◽  
Jennifer D. Roy ◽  
Robert E. Ferrell
Keyword(s):  
De Novo ◽  
Remission Rate ◽  
Leukemic Cells ◽  
Luciferase Reporter ◽  
Luciferase Expression ◽  
Nucleoside Transporter ◽  
Nucleotide Polymorphisms ◽  
Flanking Sequence ◽  
Equilibrative Nucleoside Transporter

Abstract Front-line induction chemotherapy regimens containing cytosine arabinoside (Ara-C) and anthracyclines result in 80% complete remission rate in childhood acute myeloid leukemia (AML) but their cure rate is about 35 – 50%, one of the lowest of all childhood cancers. Understanding the factors that contribute to emergence of chemoresistant leukemic cells is crucial to improving treatment outcome in children with AML. We are interested in studying the role of variation in Ara-C transport and biotransformation pathway genes in the efficacy and toxicity of treatment of childhood AML. To permeate the cell membrane, Ara-C is mainly dependent on human equilibrative nucleoside transporter 1 (hENT1; SLC29A1; gene localized to 6p21.1). Several studies have suggested an important role for altered levels of hENT1 in the chemosensitivity of AML blasts to Ara-C (Galmarini et al. Leukemia2001; 15(6):87; Gati et al. Leuk Lymphoma1998; 32(1–2):45). Osato and colleagues identified two single nucleotide polymorphisms (SNPs) in the hENT1 coding sequence that led to missense changes, but their in vitro analysis did not detect differences in the activity of variant alleles in a yeast transfection system (Osato et al. Pharmacogenetics2003;13(5):297). To identify variation in hENT1 that might influence its expression, we sequenced 1.6Kb of the proximal 5′-flanking sequence of the gene in 42 unrelated individuals and identified three SNPs at positions C-1345G, G-1050A, and G-706C. TRANSFAC analysis (www.genomatix.de) predicted that two of these (C-1345G & G-706C) would alter consensus transcription factor binding site sequences. We cloned four naturally occurring haplotypes (CGG, CAG, CGC, and GAG) using the TOPO-TA cloning kit, then transfected Cos-1 cells using the Lipofectamine 2000 protocol. Gene expression was assayed using the Promega Dual-Luciferase Reporter Assay System and read on a Molecular Devices HT Analyzer. Luciferase activity was measured at 24 and 48 hours after transfection for six replicates of every condition during three separate transfections. To correct for differences in transfection efficiencies, experimental (Photinus pyralis) luciferase activities were normalized by co-transfection with control (Renilla reniformis) luciferase plasmid. Compared to the wild type CGG haplotype, variant haplotypes CAG, CGC, and GAG drive luciferase expression at approximately 2x (p <0.0001), 1.4x (p <0.001) and 1.2x (p =0.08), respectively. This leads to the hypothesis that individuals carrying CAG or CGC haplotypes (17% of the population) exhibit higher levels of hENT1 expression and are more sensitive to Ara-C exposure. Experiments are underway to quantify gene transcripts in people of known hENT1 haplotypes. We also plan to genotype a large cohort of children with de novo AML for these three SNPs in hENT1 and correlate clinical outcomes in individuals carrying the low- versus the high-expressing haplotypes.

Base of tongue squamous cell carcinoma susceptibility: Novel candidate genetic polymorphisms identified in genome-wide association study.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e16041-e16041
Author(s):  
Carmen Silvia Passos Lima ◽  
Benilton Carvalho ◽  
Renata Pellegrino ◽  
Leticia Khater ◽  
Carlos Takahiro Chone ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Genome Wide Association Study ◽  
Snp Array ◽  
Tumor Development ◽  
Genetic Alterations ◽  
Nucleotide Polymorphisms ◽  
Functional Protein ◽  
Base Of Tongue

e16041 Background: Inherited genetic alterations, such as single nucleotide polymorphisms (SNPs), were described in association with oropharyngeal cancer risk in few reports with restrict number of SNPs analyzed. Base of tongue (BT) squamous cell carcinoma (SCC) is a common tumor of oropharynx; however, the association of SNPs and BTSCC risk is not clarified and, therefore, this was the aim of this study. Methods: DNA from 49 BTSCC patients and 49 controls was extracted using the QIamp kit (Qiagen). Each sample was genotyped individually using DNA high-resolution microarrays containing 500.568 SNPs (SNP array 5.0, Affymetrix). Further sample processing, including digestion, adaptor ligation, amplification, fragmentation, labeling, hybridization, washing and scanning was assayed according to the standard protocol. Genotype data were acquired by genotyping calling of samples using crlmm algorithm provided by Bioconductor software. The differences between groups were analyzed by the logistic regression model. The SNPs localized in genes of interest were selected by data base analysis in DAVID and NCBI websites. The validation of selected SNPs was performed by RT-PCR, using TaqMan SNP Genotyping Assays (Applied Biosystems) in all samples studied. Results: We observed 6.609 SNPs with distinct frequencies between BTSCC patients and controls. Fifty-two SNPs (0.8%) were located in coding sequence (CDS), 51 (0.8%) in 3’ and 5’- untranslated regions (UTR), 3.461 (52.4%) in up or downstream regions (DWS) and 3.045 (46.0%) in introns. Ten SNPs were selected and validated in study, including those localized in genes related to cell cycle (3’-UTR: ERP29, rs7114; MCC, rs7033; DWS: LEF1, rs2107028 and rs4245926; PTCH1, rs16909856 and rs16909859), transcription process (CDS: IKBKAP, rs3204145; 3’-UTR: ZNF415, rs3814), and cell adhesion (CDS: COL22A1, rs2292927; DWS: LY6K, rs1995467). Conclusions: Our preliminary results suggest that SNPs in genes involved in tumor development may predispose individuals to BTSCC. However, these results should be confirmed by functional protein studies and validated in larger epidemiological studies. Financial support: FAPESP and FINEP.

scholarly journals MicroRNA 648 Targets ET-1 mRNA and Is Cotranscriptionally Regulated withMICAL3by PAX5

2014 ◽  
Vol 35 (3) ◽  
pp. 514-528 ◽  
Author(s):  
Chen Li ◽  
Caryn S. Gonsalves ◽  
Marthe-Sandrine Eiymo Mwa Mpollo ◽  
Punam Malik ◽  
Stanley M. Tahara ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Posttranscriptional Regulation ◽  
Hypoxia Inducible Factor ◽  
Positive Control ◽  
Luciferase Reporter ◽  
Lim Domain ◽  
Placenta Growth Factor ◽  
Reporter Assays ◽  
Potent Vasoconstrictor ◽  
Distal Promoter

Pulmonary hypertension (PHT) is associated with high mortality in sickle cell anemia (SCA). Previously, we showed that elevated levels of placenta growth factor (PlGF) in SCA patients correlate with increased levels of the potent vasoconstrictor endothelin-1 (ET-1) and PHT. Moreover, PlGF induced the expression of ET-1 via hypoxia-inducible factor 1α. Here, we show a novel example of ET-1 posttranscriptional regulation by PlGF via action of microRNA 648 (miR-648), which is subject to transcriptional coregulation with its host gene,MICAL3(microtubule-associated monooxygenase, calponin, and LIM domain containing 3gene). PlGF repressed expression of miR-648 in endothelial cells. Luciferase reporter assays using wild-type and mutant ET-1 3′ untranslated region (UTR) constructs, and transfection of miR-648 mimics showed that miR-648 targets the 3′ UTR of ET-1 mRNA. Since miR-648 is located in a 5′-proximal intron ofMICAL3, we examined which of three potential promoters was responsible for its expression. TheMICAL3distal promoter (P1) was the predominant promoter used for transcription of pre-miR-648, and it was under positive control by PAX5 (paired box protein 5) transcription factor, as demonstrated by the loss and gain of function of PAX5 activity, and chromatin immunoprecipitation analysis. These studies provide a novel link wherein PlGF-mediated downregulation of PAX5 attenuates miR-648 expression leading to increased ET-1 levels that are known to induce PHT in SCA.

scholarly journals Kaposi's Sarcoma-Associated Herpesvirus Open Reading Frame 57 Encodes a Posttranscriptional Regulator with Multiple Distinct Activities

2000 ◽  
Vol 74 (8) ◽  
pp. 3586-3597 ◽  
Author(s):  
Jessica R. Kirshner ◽  
David M. Lukac ◽  
Jean Chang ◽  
Don Ganem
Keyword(s):  
Posttranscriptional Regulation ◽  
Kaposi's Sarcoma ◽  
Kaposi’S Sarcoma ◽  
Open Reading Frame ◽  
Luciferase Reporter ◽  
Reading Frame ◽  
Infected Cells ◽  
Kaposi's Sarcoma Associated Herpesvirus ◽  
Kaposi’S Sarcoma Associated Herpesvirus ◽  
Coding Potential

ABSTRACT Open reading frame (ORF) 57 of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a homolog of known posttranscriptional regulators that are essential for replication in other herpesviruses. Here, we examined the expression of this gene and the function(s) of its product. KSHV ORF 57 is expressed very early in infection from a 1.6-kb spliced RNA bearing several in-frame initiation codons. Its product is a nuclear protein that, in transient assays, has little effect on the expression of luciferase reporter genes driven by a variety of KSHV and heterologous promoters. However, ORF 57 protein enhances the accumulation of several viral transcripts, in a manner suggesting posttranscriptional regulation. These transcripts include not only known cytoplasmic mRNAs (e.g., ORF 59) but also a nuclear RNA (nut-1) that lacks coding potential. Finally, ORF 57 protein can also modulate the effects of the ORF 50 gene product, a classical transactivator known to be required for lytic induction. The expression from some (e.g., nut-1) but not all (e.g., tk) ORF 50-responsive promoters can be synergistically enhanced by coexpression of ORF 50 and ORF 57. This effect is not due to upregulation of ORF 50 expression but rather to a posttranslational enhancement of the transcriptional activity of ORF 50. These data indicate that ORF 57 is a powerful pleiotropic effector that can act on several posttranscriptional levels to modulate the expression of viral genes in infected cells.

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