Displaying publications 181 - 200 of 1023 in total

Abstract:
Sort:
  1. A Comprehensive Gene Inventory for Glucosinolate Biosynthetic Pathway in Arabidopsis thaliana
    Harun S, Abdullah-Zawawi MR, Goh HH, Mohamed-Hussein ZA
    J Agric Food Chem, 2020 Jul 15;68(28):7281-7297.
    PMID: 32551569 DOI: 10.1021/acs.jafc.0c01916
    Glucosinolates (GSLs) are plant secondary metabolites comprising sulfur and nitrogen mainly found in plants from the order of Brassicales, such as broccoli, cabbage, and Arabidopsis thaliana. The activated forms of GSL play important roles in fighting against pathogens and have health benefits to humans. The increasing amount of data on A. thaliana generated from various omics technologies can be investigated more deeply in search of new genes or compounds involved in GSL biosynthesis and metabolism. This review describes a comprehensive inventory of A. thaliana GSLs identified from published literature and databases such as KNApSAcK, KEGG, and AraCyc. A total of 113 GSL genes encoding for 23 transcription components, 85 enzymes, and five protein transporters were experimentally characterized in the past two decades. Continuous efforts are still on going to identify all molecules related to the production of GSLs. A manually curated database known as SuCCombase (http://plant-scc.org) was developed to serve as a comprehensive GSL inventory. Realizing lack of information on the regulation of GSL biosynthesis and degradation mechanisms, this review also includes relevant information and their connections with crosstalk among various factors, such as light, sulfur metabolism, and nitrogen metabolism, not only in A. thaliana but also in other crucifers.
    Matched MeSH terms: Gene Expression Regulation, Plant
  2. Clinical significance of aberrant microRNAs expression in predicting disease relapse/refractoriness to treatment in diffuse large B-cell lymphoma: A meta-analysis
    Ting CY, Liew SM, Price A, Gan GG, Bee-Lan Ong D, Tan SY, et al.
    Crit Rev Oncol Hematol, 2019 Dec;144:102818.
    PMID: 31733445 DOI: 10.1016/j.critrevonc.2019.102818
    The clinical significance of aberrantly expressed microRNAs in predicting treatment response to chemotherapy in diffuse large B-cell lymphoma patients (DLBCL) remains uncertain. Feasibility of microRNA testing to predict treatment outcome was evaluated. Twenty-two types of aberrantly expressed microRNAs were associated with poor treatment response; pooled hazard ratio (HR) was 2.14 [95%CI:1.78-2.57, P 
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  3. Bacterial regulatory RNAs: complexity, function, and putative drug targeting
    Cheah HL, Raabe CA, Lee LP, Rozhdestvensky TS, Citartan M, Ahmed SA, et al.
    Crit Rev Biochem Mol Biol, 2018 08;53(4):335-355.
    PMID: 29793351 DOI: 10.1080/10409238.2018.1473330
    Over the past decade, RNA-deep sequencing has uncovered copious non-protein coding RNAs (npcRNAs) in bacteria. Many of them are key players in the regulation of gene expression, taking part in various regulatory circuits, such as metabolic responses to different environmental stresses, virulence, antibiotic resistance, and host-pathogen interactions. This has contributed to the high adaptability of bacteria to changing or even hostile environments. Their mechanisms include the regulation of transcriptional termination, modulation of translation, and alteration of messenger RNA (mRNA) stability, as well as protein sequestration. Here, the mechanisms of gene expression by regulatory bacterial npcRNAs are comprehensively reviewed and supplemented with well-characterized examples. This class of molecules and their mechanisms of action might be useful targets for the development of novel antibiotics.
    Matched MeSH terms: Gene Expression Regulation
  4. Association of Micro RNA and Postoperative Cognitive Dysfunction: A Review
    Yazit NAA, Juliana N, Das S, Teng NIMF, Fahmy NM, Azmani S, et al.
    Mini Rev Med Chem, 2020;20(17):1781-1790.
    PMID: 32564754 DOI: 10.2174/1389557520666200621182717
    Postoperative Cognitive Dysfunction (POCD) refers to the condition of neurocognitive decline following surgery in a cognitive and sensory manner. There are several risk factors, which may be life-threatening for this condition. Neuropsychological assessment of this condition is very important. In the present review, we discuss the association of apolipoprotein epsilon 4 (APOE ε4) and few miRNAs with POCD, and highlight the clinical importance for prognosis, diagnosis and treatment of POCD. Microarray is a genome analysis that can be used to determine DNA abnormalities. This current technique is rapid, efficient and high-throughout. Microarray techniques are widely used to diagnose diseases, particularly in genetic disorder, chromosomal abnormalities, mutations, infectious diseases and disease-relevant biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are widely found distributed in eukaryotes. Few miRNAs influence the nervous system development, and nerve damage repair. Microarray approach can be utilized to understand the miRNAs involved and their pathways in POCD development, unleashing their potential to be considered as a diagnostic marker for POCD. This paper summarizes and identifies the studies that use microarray based approaches for POCD analysis. Since the application of microarray in POCD is expanding, there is a need to review the current knowledge of this approach.
    Matched MeSH terms: Gene Expression Regulation
  5. Fulltext DNA Methylation of Human Choline Kinase Alpha Promoter-Associated CpG Islands in MCF-7 Cells
    Mohamed Sa'dom SAF, Raikundalia S, Shamsuddin S, See Too WC, Few LL
    Genes (Basel), 2021 06 01;12(6).
    PMID: 34205960 DOI: 10.3390/genes12060853
    Choline kinase (CK) is the enzyme catalyzing the first reaction in CDP-choline pathway for the biosynthesis of phosphatidylcholine. Higher expression of the α isozyme of CK has been implicated in carcinogenesis, and inhibition or downregulation of CKα (CHKA) is a promising anticancer approach. This study aimed to investigate the regulation of CKα expression by DNA methylation of the CpG islands found on the promoter of this gene in MCF-7 cells. Four CpG islands have been predicted in the 2000 bp promoter region of ckα (chka) gene. Six CpG island deletion mutants were constructed using PCR site-directed mutagenesis method and cloned into pGL4.10 vectors for promoter activity assays. Deletion of CpG4C region located between -225 and -56 significantly increased the promoter activity by 4-fold, indicating the presence of important repressive transcription factor binding site. The promoter activity of methylated full-length promoter was significantly lower than the methylated CpG4C deletion mutant by 16-fold. The results show that DNA methylation of CpG4C promotes the binding of the transcription factor that suppresses the promoter activity. Electrophoretic mobility shift assay analysis showed that cytosine methylation at MZF1 binding site in CpG4C increased the binding of putative MZF1 in nuclear extract. In conclusion, the results suggest that DNA methylation decreased the promoter activity by promoting the binding of putative MZF1 transcription factor at CpG4C region of the ckα gene promoter.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  6. Role of NF-kβ factor Rel2 during Plasmodium falciparum and bacterial infection in Anopheles dirus
    Khan MB, Liew JW, Leong CS, Lau YL
    Parasit Vectors, 2016 Sep 29;9(1):525.
    PMID: 27688040
    Anopheles mosquitoes transmit malaria which is one of the world's most threatening diseases. Anopheles dirus (sensu stricto) is among the main vectors of malaria in South East Asia. The mosquito innate immune response is the first line of defence against malaria parasites during its development. The immune deficiency (IMD) pathway, a conserved immune signaling pathway, influences anti-Plasmodium falciparum activity in Anopheles gambiae, An. stephensi and An. albimanus. The aim of the study was to determine the role of Rel2, an IMD pathway-controlled NF-kappaβ transcription factor, in An. dirus.
    Matched MeSH terms: Gene Expression Regulation
  7. Fulltext Research trends in microarray data analysis: modelling gene regulatory network by integrating transcription factors data
    Farzana Kabir Ahmad, Siti Sakira Kamaruddin
    Scientific Research Journal, 2015;12(1):1-10.
    MyJurnal
    The invention of microarray technology has enabled expression levels of thousands of genes to be monitored at once. This modernized approach has created large amount of data to be examined. Recently, gene regulatory network has been an interesting topic and generated impressive research goals in computational biology. Better understanding of the genetic regulatory processes would bring significant implications in the biomedical fields and many other pharmaceutical industries. As a result, various mathematical and computational methods have been used to model gene regulatory network from microarray data. Amongst those methods, the Bayesian network model attracts the most attention and has become the prominent technique since it can capture nonlinear and stochastic relationships between variables. However, structure learning of this model is NP-hard and computationally complex as the number of potential edges increase drastically with the number of genes. In addition, most of the studies only focused on the predicted results while neglecting the fact that microarray data is a fragmented information on the whole biological process. Hence this study proposed a network-based inference model that combined biological knowledge in order to verify the constructed gene regulatory relationships. The gene regulatory network is constructed using Bayesian network based on low-order conditional independence approach. This technique aims to identify from the data the dependencies to construct the network structure, while addressing the structure learning problem. In addition, three main toolkits such as Ensembl, TFSearch and TRANSFAC have been used to determine the false positive edges and verify reliability of regulatory relationships. The experimental results show that by integrating biological knowledge it could enhance the precision results and reduce the number of false positive edges in the trained gene regulatory network.
    Matched MeSH terms: Gene Expression Regulation
  8. Fulltext Subversion of immunoproteasome subunit expression in dengue virus serotype 2-infected HepG2 cells
    Gan CS, Lim PJ, Razif MF, Yusof R, Othman S
    Rev Soc Bras Med Trop, 2017 Jan-Feb;50(1):99-103.
    PMID: 28327809 DOI: 10.1590/0037-8682-0207-2016
    INTRODUCTION:: Infection with all serotypes of dengue virus (DV) results in augmented antigen presentation by MHC class I molecules. However, the upregulation of immunoproteasome subunits only results from infection with two serotypes. This study aims to elucidate changes in the expression of immunoproteasome subunits resulting from infection with DV, particularly DV serotype 2 (DV2).

    METHODS:: HepG2 cells were grown in various culture milieu. Total cellular RNA and proteins were extracted and quantified.

    RESULTS:: Results demonstrated sequestration of immunoproteasome subunits LMP2 and LMP7 in DV2-infected cells.

    CONCLUSIONS:: This study provides insights into the mechanisms underlying immune evasion by DV.
    Matched MeSH terms: Gene Expression Regulation
  9. Downregulation of human choline kinase α gene expression by miR-876-5p
    Ayub Khan SM, Few LL, See Too WC
    Mol Med Rep, 2018 May;17(5):7442-7450.
    PMID: 29568919 DOI: 10.3892/mmr.2018.8762
    Choline kinase (CK) is the first enzyme in the CDP-choline pathway for the synthesis of phosphatidylcholine, the most abundant phospholipid in the mammalian cell membrane. This enzyme exists as three isozymes (α1, α2 and β) and the CKα isozyme has been implicated in cancer pathogenesis. Inhibition of CK activity has been proposed for cancer therapies. MicroRNAs (miRNAs/miRs) are non‑coding RNAs that serve important roles in diverse biological pathways and human diseases, including cancer. However, the regulation of CKα gene expression by miRNAs has never been investigated, to the best of the authors' knowledge. In the present study, two miRNA mimics, miR‑876‑5p and miR‑646, were transfected into the HepG2 cell line and the effect of these miRNAs on the levels of CKα mRNA were determined by reverse transcription‑quantitative polymerase chain reaction. Cells transfected with 25 nM miR‑876‑5p for 48 h exhibited significantly lower levels of CKα mRNA. Following optimization, miR‑876‑5p caused four times lower levels of CKα mRNA compared to the negative control. Effects of the miRNAs on HepG2 cell viability and cellular morphology were additionally analyzed using an MTT cell viability assay and scanning electron microscopy, respectively. HepG2 cells that were transfected with the optimum concentration of miR‑876‑5p for the optimum duration exhibited 25% lower viability than negative control and signs of apoptosis in electron micrographs. The results suggested miR‑876‑5p as a potential miRNA modulator of CKα expression in the cells, and may be relevant for the design of more effective anticancer strategy targeting CK.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  10. Fulltext Transcriptional profiling of coaggregation interactions between Streptococcus gordonii and Veillonella parvula by Dual RNA-Seq
    Mutha NVR, Mohammed WK, Krasnogor N, Tan GYA, Wee WY, Li Y, et al.
    Sci Rep, 2019 05 21;9(1):7664.
    PMID: 31113978 DOI: 10.1038/s41598-019-43979-w
    Many oral bacteria form macroscopic clumps known as coaggregates when mixed with a different species. It is thought that these cell-cell interactions are critical for the formation of mixed-species biofilms such as dental plaque. Here, we assessed the impact of coaggregation between two key initial colonizers of dental plaque, Streptococcus gordonii and Veillonella parvula, on gene expression in each partner. These species were shown to coaggregate in buffer or human saliva. To monitor gene regulation, coaggregates were formed in human saliva and, after 30 minutes, whole-transcriptomes were extracted for sequencing and Dual RNA-Seq analysis. In total, 272 genes were regulated in V. parvula, including 39 genes in oxidoreductase processes. In S. gordonii, there was a high degree of inter-sample variation. Nevertheless, 69 genes were identified as potentially regulated by coaggregation, including two phosphotransferase system transporters and several other genes involved in carbohydrate metabolism. Overall, these data indicate that responses of V. parvula to coaggregation with S. gordonii are dominated by oxidative stress-related processes, whereas S. gordonii responses are more focussed on carbohydrate metabolism. We hypothesize that these responses may reflect changes in the local microenvironment in biofilms when S. gordonii or V. parvula immigrate into the system.
    Matched MeSH terms: Gene Expression Regulation
  11. Genetic diversity and in silico evidence of target-site mutation in the EPSPS gene in endowing glyphosate resistance in Eleusine indica (L.) from Malaysia
    Franci J, Lam KW, Chuah TS, Cha TS
    Pestic Biochem Physiol, 2020 May;165:104556.
    PMID: 32359543 DOI: 10.1016/j.pestbp.2020.104556
    Glyphosate-resistant populations of Eleusine indica are widespread in several states of Malaysia. A whole-plant bioassay confirmed that eight out of the 17 populations tested were resistant to glyphosate at double the recommended rate of 2.44 kg ha-1. Screening with allele-specific PCR (AS-PCR) revealed that resistant plants contained an EPSPS gene with either the homozygous S/S-106 or the heterozygous P/S-106 alleles. All susceptible plants contained only the homozygous P/P-106 allele. In addition, DNA sequences of the full-length EPSPS gene from one susceptible (SB) and four resistant (R2, R6, R8 and R11) populations revealed an amino acid substitution of T102I in all the resistant plants, while another substitution of P381L was only found in resistant populations R6 and R11. The significance of the P381L mutation was examined by Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) and residue interaction network (RIN) analyses, which suggests the P381L mutation may contribute to resistance. Mutations at 102 and 106 occur widely in the EPSPS gene of glyphosate-resistant E. indica populations from Malaysia with the TIPS mutation. In addition, the P381L mutation could also contribute to resistance.
    Matched MeSH terms: Gene Expression Regulation, Plant
  12. Unveiling the Role of Cytochrome P450 (2E1) in Human Brain Specifically in Parkinson's Disease - Literature Review
    Shah A, Ong CE, Pan Y
    Curr Drug Metab, 2021;22(9):698-708.
    PMID: 34325630 DOI: 10.2174/1389200222666210729115151
    BACKGROUND: In recent years, the significance of cytochrome P450 enzymes (CYPs) has expanded beyond their role in the liver. Factors such as genetics, environmental toxins, drug biotransformation and underlying diseases mediate the expression of these enzymes. Among the CYP enzymes, CYP2E1, a well-recognized monooxygenase enzyme involved in the metabolism of various endogenous and exogenous substances, plays a crucial role in the brain concerning the development of Parkinson's disease. The expression of CYP2E1 varies in different brain regions making certain regions more vulnerable than others. CYP2E1 expression is inducible which generates tissuedamaging radicals leading to oxidative stress, mitochondrial dysfunction and ultimately neurodegeneration.

    OBJECTIVE: Less is understood about the role of CYP2E1 in the central nervous system, therefore the purpose of the study was to investigate the relationship between the expression and activity of CYP2E1 enzyme relevant to Parkinson's disease and to identify whether an increase in the expression of CYP2E1 is associated with neurodegeneration.

    METHODS: The objectives of the study were achieved by implicating an unsystematic integrative literature review approach in which the literature was qualitatively analysed, critically evaluated and a new theory with an overall view of the mechanism was presented.

    RESULTS: The contribution of CYP2E1 in the development of Parkinson's disease was found to be significant as the negative effects of CYP2E1 overshadowed its protective detoxifying role.

    CONCLUSION: Overexpression of CYP2E1 seems detrimental to dopaminergic neurons, therefore, to overcome this, a synthetic biochemical is required, which paves the way for further research and development of valuable biomolecules.

    Matched MeSH terms: Gene Expression Regulation
  13. The Mechanisms of Inhibition of Advanced Glycation End Products Formation through Polyphenols in Hyperglycemic Condition
    Khangholi S, Majid FA, Berwary NJ, Ahmad F, Aziz RB
    Planta Med, 2016 Jan;82(1-2):32-45.
    PMID: 26550791 DOI: 10.1055/s-0035-1558086
    Glycation, the non-enzymatic binding of glucose to free amino groups of an amino acid, yields irreversible heterogeneous compounds known as advanced glycation end products. Those products play a significant role in diabetic complications. In the present article we briefly discuss the contribution of advanced glycation end products to the pathogenesis of diabetic complications, such as atherosclerosis, diabetic retinopathy, nephropathy, neuropathy, and wound healing. Then we mention the various mechanisms by which polyphenols inhibit the formation of advanced glycation end products. Finally, recent supporting documents are presented to clarify the inhibitory effects of polyphenols on the formation of advanced glycation end products. Phytochemicals apply several antiglycation mechanisms, including glucose metabolism, amelioration of oxidative stress, scavenging of dicarbonyl species, and up/down-regulation of gene expression. To utilize polyphenols in order to remedy diabetic complications, we must explore, examine and clarify the action mechanisms of the components of polyphenols.
    Matched MeSH terms: Gene Expression Regulation
  14. Fulltext MicroRNAs Regulate Cell Cycle and Cell Death Pathways in Glioblastoma
    Sati ISEE, Parhar I
    Int J Mol Sci, 2021 Dec 17;22(24).
    PMID: 34948346 DOI: 10.3390/ijms222413550
    Glioblastoma (GBM), a grade IV brain tumor, is known for its heterogenicity and its resistance to the current treatment regimen. Over the last few decades, a significant amount of new molecular and genetic findings has been reported regarding factors contributing to GBM's development into a lethal phenotype and its overall poor prognosis. MicroRNA (miRNAs) are small non-coding sequences of RNA that regulate and influence the expression of multiple genes. Many research findings have highlighted the importance of miRNAs in facilitating and controlling normal biological functions, including cell differentiation, proliferation, and apoptosis. Furthermore, miRNAs' ability to initiate and promote cancer development, directly or indirectly, has been shown in many types of cancer. There is a clear association between alteration in miRNAs expression in GBM's ability to escape apoptosis, proliferation, and resistance to treatment. Further, miRNAs regulate the already altered pathways in GBM, including P53, RB, and PI3K-AKT pathways. Furthermore, miRNAs also contribute to autophagy at multiple stages. In this review, we summarize the functions of miRNAs in GBM pathways linked to dysregulation of cell cycle control, apoptosis and resistance to treatment, and the possible use of miRNAs in clinical settings as treatment and prediction biomarkers.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  15. Distinct microRNA expression pattern in breast cancer cells following anti-neoplastic treatment: A systematic review and functional analysis of microRNA target genes
    Qatrun Nada D, Masniza ML, Abdullah N, Marlini M, Elias MH, Pathmanathan SG, et al.
    Malays J Pathol, 2022 Dec;44(3):367-385.
    PMID: 36591707
    Breast cancer remains a significant cause of mortality in females worldwide, despite advances in technology and treatment. MicroRNA expression in breast cancer is studied both as potential biomarkers and for therapeutic purposes. Accumulated evidence revealed microRNA profile of various types of cancer cells following antineoplastic treatment. The progression of research in this area provides better understanding on the anti-cancer mechanism of various natural compounds and drugs specifically on the microRNA regulation. Hence, we aim to systematically review differentially expressed microRNA in MCF-7, a commonly studied breast cancer cell line, after treatment with anti-neoplastic agents. Relevant keywords were used to screen for research articles that reported on the differentially expressed microRNAs in experimental models of MCF-7 before and after anti-neoplastic treatment. Target genes of microRNAs were identified from MiRTarbase and further in silico functional analysis of the target genes were performed using DAVID bioinformatic resources. Two upregulated microRNAs (mir-200c and let-7d) and 3 downregulated microRNAs (mir-27a, mir-27b and mir-203) were identified by highest number of studies. Three microRNAs (let-7a, mir-23a and mir-7) showed inconsistent direction of expression. Genes functional analysis revealed the regulatory effect of microRNA on genes related to angiogenesis, hypoxia, P53, FoxO and PI3K-AKT signalling. Clusters of genes associated to the pathway of angiogenesis, cancers, cell proliferation and apoptosis were noted through protein-protein interaction analysis. MicroRNAs, especially the mir-200c, let-7d, mir-27a, mir-27b and mir-203 from this review could be further validated experimentally to serve as molecular target or biomarkers for anti-neoplastic therapy.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  16. Fulltext The Regulatory Role of MicroRNAs in Breast Cancer
    Loh HY, Norman BP, Lai KS, Rahman NMANA, Alitheen NBM, Osman MA
    Int J Mol Sci, 2019 Oct 06;20(19).
    PMID: 31590453 DOI: 10.3390/ijms20194940
    MicroRNAs (miRNAs) are small non-coding RNA molecules which function as critical post-transcriptional gene regulators of various biological functions. Generally, miRNAs negatively regulate gene expression by binding to their selective messenger RNAs (mRNAs), thereby leading to either mRNA degradation or translational repression, depending on the degree of complementarity with target mRNA sequences. Aberrant expression of these miRNAs has been linked etiologically with various human diseases including breast cancer. Different cellular pathways of breast cancer development such as cell proliferation, apoptotic response, metastasis, cancer recurrence and chemoresistance are regulated by either the oncogenic miRNA (oncomiR) or tumor suppressor miRNA (tsmiR). In this review, we highlight the current state of research into miRNA involved in breast cancer, with particular attention to articles published between the years 2000 to 2019, using detailed searches of the databases PubMed, Google Scholar, and Scopus. The post-transcriptional gene regulatory roles of various dysregulated miRNAs in breast cancer and their potential as therapeutic targets are also discussed.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
  17. An Overview of Molecular Basis and Genetic Modification of Floral Organs Genes: Impact of Next-Generation Sequencing
    Patil RV, Hadawale KN, Ramli ANM, Wadkar SS, Bhuyar P
    Mol Biotechnol, 2023 Jun;65(6):833-848.
    PMID: 36544065 DOI: 10.1007/s12033-022-00633-7
    In plant development, flowering is the most widely studied process. Floral forms show large diversity in different species due to simple variations in basic architecture. To determine the floral gene expression during the past decade, MADS-box genes have identified as key regulators in both reproductive and vegetative plant development. Traditional genetics and functional genomics tools are now available to elucidate the expression and function of this complex gene family on a much larger scale. Moreover, comparative analysis of the MADS-box genes in diverse flowering and non-flowering plants, boosted by various molecular technologies such as ChIP and next-generation DNA sequencing, contributes to our understanding of how this important gene family has expanded during the evolution of land plants. Likewise, the big data analysis revealed combined activity of transcriptional regulators and floral organ identity factors regulate the flower developmental programs. Thus, with the help of cutting-edge technologies like RNA-Sequencing, sex determination is now better understood in few non-model plants Therefore, the recent advances in next-generation sequencing (NGS) should enable researchers to identify the full range of floral gene functions, which will significantly help to understand plant development and evolution. This review summarizes the floral homeotic genes in model and non-model species to understand the flower development genes and dioecy evolution.
    Matched MeSH terms: Gene Expression Regulation, Plant
  18. Fulltext DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium hybrid
    Khairul-Anuar MA, Mazumdar P, Othman RY, Harikrishna JA
    Ann Bot, 2022 Sep 26;130(4):579-594.
    PMID: 35980362 DOI: 10.1093/aob/mcac103
    BACKGROUND: Flower pigment and shape are determined by the coordinated expression of a set of structural genes during flower development. R2R3-MYB transcription factors are known regulators of structural gene expression. The current study focused on two members of this large family of transcription factors that were predicted to have roles in pigment biosynthesis and organ shape development in orchids.

    METHODS: Phylogenetic analysis was used to identify candidate Dendrobium catenatum R2R3-MYB (DcaMYB) sequences associated with pigment and cell shape development. Gene silencing of candidate DhMYBs in Dendrobium hybrid by direct application of dsRNA to developing flowers was followed by observation of gene expression level and flower phenotypes. Silencing of the structural gene chalcone synthase was used as a comparative control.

    KEY RESULTS: Ten candidate flower-associated DcaMYBs were identified. Flowers treated with dsRNA of DhMYB22 and DhMYB60 sequences were less pigmented and had relatively low expression of anthocyanin biosynthetic genes (F3'H and DFR), lower total anthocyanin concentration and markedly lower levels of cyanidin-3-glucoside and cyanidin-3-rutinoside. Petals of DhMYB22-treated flowers and sepals of DhMYB60-treated flowers showed the greatest colour difference relative to the same organs in untreated flowers. DhMYB22-treated flowers had relatively narrow and constricted lips, while DhMYB60-treated flowers had narrow and constricted sepals. No significant difference in shape was observed for DhCHS-treated or untreated flowers.

    CONCLUSIONS: Our results demonstrate that DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium. This is a first report of MYB regulation of floral organ shape in orchids.

    Matched MeSH terms: Gene Expression Regulation, Plant
  19. Variable expansin expression in Arabidopsis leads to different growth responses
    Goh HH, Sloan J, Malinowski R, Fleming A
    J Plant Physiol, 2014 Feb 15;171(3-4):329-39.
    PMID: 24144490 DOI: 10.1016/j.jplph.2013.09.009
    Expansins have long been implicated in the control of cell wall extensibility. However, despite ample evidence supporting a role for these proteins in the endogenous mechanism of plant growth, there are also examples in the literature where the outcome of altered expansin gene expression is difficult to reconcile with a simplistic causal linkage to growth promotion. To investigate this problem, we report on the analysis of transgenic Arabidopsis plants in which a heterologous cucumber expansin can be inducibly overexpressed. Our results indicate that the effects of expansin expression on growth depend on the degree of induction of expansin expression and the developmental pattern of organ growth. They support the role of expansin in directional cell expansion. They are also consistent with the idea that excess expansin might itself impede normal activities of cell wall modifications, culminating in both growth promotion and repression depending on the degree of expression.
    Matched MeSH terms: Gene Expression Regulation, Plant
  20. Fulltext Clinical Theragnostic Relationship between Chemotherapeutic Resistance, and Sensitivity and miRNA Expressions in Head and Neck Cancers: A Systematic Review and Meta-Analysis Protocol
    Shaw P, Raymond G, Senthilnathan R, Kumarasamy C, Baxi S, Suresh D, et al.
    Genes (Basel), 2021 Dec 20;12(12).
    PMID: 34946979 DOI: 10.3390/genes12122029
    Background: The microRNAs (miRNAs) are small noncoding single-stranded RNAs typically 19-25 nucleotides long and regulated by cellular and epigenetic factors. These miRNAs plays important part in several pathways necessary for cancer development, an altered miRNA expression can be oncogenic or tumor-suppressive. Recent experimental results on miRNA have illuminated a different perspective of the molecular pathogenesis of head and neck cancers. Regulation of miRNA can have a detrimental effect on the efficacy of chemotherapeutic drugs in both neoadjuvant and adjuvant settings. This miRNA-induced chemoresistance can influence the prognosis and survival rate. The focus of the study is on how regulations of various miRNA levels contribute to chemoresistance in head and neck cancer (HNC). Recent findings suggest that up or down-regulation of miRNAs may lead to resistance towards various chemotherapeutic drugs, which may influence the prognosis. Methods: Studies on miRNA-specific chemoresistance in HNC were collected through literary (bibliographic) databases, including SCOPUS, PubMed, Nature, Elsevier, etc., and were systematically reviewed following PRISMA-P guidelines (Preferred Reporting Items for Systematic Review and Meta-analysis Protocol). We evaluated various miRNAs, their up and downregulation, the effect of altered regulation on the patient's prognosis, resistant cell lines, etc. The data evaluated will be represented in the form of a review and meta-analysis. Discussion: This meta-analysis aims to explore the miRNA-induced chemoresistance in HNC and thus to aid further researches on this topic. PROSPERO registration: CRD42018104657.
    Matched MeSH terms: Gene Expression Regulation, Neoplastic
Related Terms
Filters
Contact Us

Please provide feedback to Administrator ([email protected])

External Links