• Title/Summary/Keyword: RNA silencing

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Effects of PLCE1 Gene Silencing by RNA Interference on Cell Cycling and Apoptosis in Esophageal Carcinoma Cells

  • Zhao, Li;Wei, Zi-Bai;Yang, Chang-Qing;Chen, Jing-Jing;Li, Dan;Ji, Ai-Fang;Ma, Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5437-5442
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    • 2014
  • Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a poor prognosis. The phospholipase $C{\varepsilon}$ gene (PLCE1) encodes a novel ras-related protein effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion. However, molecular mechanisms pertinent to ESCC are unclear. We therefore designed PLCE1-special small interfering RNA and transfected to esophageal squamous cell (EC) 9706 cells to investigat the effects of PLCE1 gene silencing on the cell cycle and apoptosis of ESCC and indicate its important role in the development of ESCC. Esophageal cancer tissue specimens and normal esophageal mucosa were obtained and assayed by immunohistochemical staining to confirm overexpression of PLCE1 in neoplasias. Fluorescence microscopy was used to examine transfection efficiency, while the result of PLCE1 silencing was examined by reverse transcription (RT-PCR). Flow cytometry and annexin V apoptosis assays were used to assess the cell cycle and apoptosis, respectively. Expression of cyclin D1 and caspase-3 was detected by Western-blotting. The level of PLCE1 protein in esophageal cancer tissue was significantly higher than that in normal tissue. After transfection, the expression of PLCE1 mRNA in EC 9706 was significantly reduced, compared with the control group. Furthermore, flow cytometry results suggested that the PLCE1 gene silencing arrested the cell cycle in the G0/G1 phase; apoptosis was significantly higher than in the negative control group and mock group. PLCE1 gene silencing by RNAi resulted in decreased expression of cyclin D1 and increased expression of caspase-3. Our study suggests that PLCE1 may be an oncogene and play an important role in esophageal carcinogenesis through regulating proteins which control cell cycling and apoptosis.

In Silico Study of miRNA Based Gene Regulation, Involved in Solid Cancer, by the Assistance of Argonaute Protein

  • Rath, Surya Narayan;Das, Debasrita;Konkimalla, V Badireenath;Pradhan, Sukanta Kumar
    • Genomics & Informatics
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    • v.14 no.3
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    • pp.112-124
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    • 2016
  • Solid tumor is generally observed in tissues of epithelial or endothelial cells of lung, breast, prostate, pancreases, colorectal, stomach, and bladder, where several genes transcription is regulated by the microRNAs (miRNAs). Argonaute (AGO) protein is a family of protein which assists in miRNAs to bind with mRNAs of the target genes. Hence, study of the binding mechanism between AGO protein and miRNAs, and also with miRNAs-mRNAs duplex is crucial for understanding the RNA silencing mechanism. In the current work, 64 genes and 23 miRNAs have been selected from literatures, whose deregulation is well established in seven types of solid cancer like lung, breast, prostate, pancreases, colorectal, stomach, and bladder cancer. In silico study reveals, miRNAs namely, miR-106a, miR-21, and miR-29b-2 have a strong binding affinity towards PTEN, TGFBR2, and VEGFA genes, respectively, suggested as important factors in RNA silencing mechanism. Furthermore, interaction between AGO protein (PDB ID-3F73, chain A) with selected miRNAs and with miRNAs-mRNAs duplex were studied computationally to understand their binding at molecular level. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding miRNAs based gene silencing mechanism in solid cancer.

Role of Long Intergenic Nonprotein-Coding RNA 00511 in Nod-Like Receptor Protein Pyrin Domain 3-Induced Chondrocyte Pyroptosis via the MicroRNA-9-5p/FUT1 Axis

  • Tianjun Zhai;Zengqiao Zhang;Xiaoshen Hu;Dongyi He;Wei Feng
    • Journal of Microbiology and Biotechnology
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    • v.34 no.7
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    • pp.1511-1521
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    • 2024
  • This study aimed to determine the function of LINC00511 in Nod-Like Receptor Pyrin Domain 3 inflammasome-mediated chondrocyte pyroptosis via the regulation of miR-9-5p and FUT 1. Chondrocyte inflammatory injury was induced by treating chondrocytes with LPS. Afterwards, the levels of IL-1β and IL-18, the expression of NLRP3, ASC, Caspase-1, and GSDMD, cell viability, and LDH activity in chondrocytes were assessed. LINC00511 expression in LPS-treated chondrocytes was detected, and LINC00511 was subsequently silenced to analyse its role in chondrocyte pyroptosis. The subcellular localization of LINC00511 was predicted and verified. Furthermore, the binding relationships between LINC00511 and miR-9-5p and between miR-9-5p and FUT1 were validated. LINC00511 regulated NLRP3 inflammasome-mediated chondrocyte pyroptosis through the miR-9-5p/FUT1 axis. LPS-treated ATDC5 cells exhibited elevated levels of inflammatory injury; increased levels of NLRP3, ASC, Caspase-1, and GSDMD; reduced cell viability; increased LDH activity; and increased LINC00511 expression, while LINC00511 silencing inhibited the NLRP3 inflammasome to restrict LPS-induced chondrocyte pyroptosis. Next, LINC00511 sponged miR-9-5p, which targeted FUT1. Silencing LINC00511 suppressed FUT1 by upregulating miR-9-5p. Additionally, downregulation of miR-9-5p or overexpression of FUT1 neutralized the suppressive effect of LINC00511 knockdown on LPS-induced chondrocyte pyroptosis. Silencing LINC00511 inhibited the NLRP3 inflammasome to quench Caspase-1-dependent chondrocyte pyroptosis in OA by promoting miR-9-5p and downregulating FUT1.

Lentivirus-mediated Silencing of Rhomboid Domain Containing 1 Suppresses Tumor Growth and Induces Apoptosis in Hepatoma HepG2 Cells

  • Liu, Xue-Ni;Tang, Zheng-Hao;Zhang, Yi;Pan, Qing-Chun;Chen, Xiao-Hua;Yu, Yong-Sheng;Zang, Guo-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.1
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    • pp.5-9
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    • 2013
  • Rhomboids were identified as the first intramembrane serine proteases about 10 years ago. Since then, the study of the rhomboid protease family has blossomed. Rhomboid domain containing 1 (RHBDD1), highly-expressed in human testis, contains a rhomboid domain with unknown function. In the present study, we tested the hypothesis that RHBDD1 was associated with proliferation and apoptosis in hepatocellular carcinoma using recombinant lentivirus-mediated silencing of RHBDD1 in HepG2 cells. Our results showed that down-regulation of RHBDD1 mRNA levels markedly suppressed proliferation and colony formation capacity of HepG2 human hepatoma cancer cells in vitro, and induced cell cycle arrest. We also found that RHBDD1 silencing could obviously trigger HepG2 cell apoptosis. In summary, it was demonstrated that RHBDD1 might be a positive regulator for proliferative and apoptotic characteristics of hepatocellular carcinoma.

miR-153 Silencing Induces Apoptosis in the MDA-MB-231 Breast Cancer Cell Line

  • Anaya-Ruiz, Maricruz;Cebada, Jorge;Delgado-Lopez, Guadalupe;Sanchez-Vazquez, Maria Luisa;Perez-Santos, Jose Luis Martin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.2983-2986
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    • 2013
  • MicroRNAs (miRNAs) are small, non-coding RNAs (18-25 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. In this context, the present study aimed to evaluate the in vitro effects of miR-153 inhibition in the breast carcinoma cell line MDA-MB-231. Forty-eight hours after MDA-MB-231 cells were transfected with the miR-153 inhibitor, an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was utilized to determine the effects of miR-153 on cell viability. Flow cytometry analysis and assessment of caspase 3/7 activity were adopted to determine whether miR-153 affects the proliferation rates and apoptosis levels of MDA-MB-231 cells. Our results showed that silencing of miR-153 significantly inhibited growth when compared to controls at 48 hours, reducing proliferation by 37.6%, and inducing apoptosis. Further studies are necessary to corroborate our findings and examine the potential use of this microRNA in future diagnostic and therapeutic interventions.

Phagocytosis-associated genes in Acanthamoeba castellanii feeding on Escherichia coli

  • Min-Jeong Kim;Eun-Kyung Moon;Hye-Jeong Jo;Fu-Shi Quan;Hyun-Hee Kong
    • Parasites, Hosts and Diseases
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    • v.61 no.4
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    • pp.397-404
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    • 2023
  • Acanthamoeba species are free-living amoebae those are widely distributed in the environment. They feed on various microorganisms, including bacteria, fungi, and algae. Although majority of the microbes phagocytosed by Acanthamoeba spp. are digested, some pathogenic bacteria thrive within them. Here, we identified the roles of 3 phagocytosis-associated genes (ACA1_077100, ACA1_175060, and AFD36229.1) in A. castellanii. These 3 genes were upregulated after the ingestion of Escherichia coli. However, after the ingestion of Legionella pneumophila, the expression of these 3 genes was not altered after the consumption of L. pneumophila. Furthermore, A. castellanii transfected with small interfering RNS (siRNA) targeting the 3 phagocytosis-associated genes failed to digest phagocytized E. coli. Silencing of ACA1_077100 disabled phagosome formation in the E. coli-ingesting A. castellanii. Alternatively, silencing of ACA1_175060 enabled phagosome formation; however, phagolysosome formation was inhibited. Moreover, suppression of AFD36229.1 expression prevented E. coli digestion and consequently led to the rupturing of A. castellanii. Our results demonstrated that the ACA1_077100, ACA1_175060, and AFD36229.1 genes of Acanthamoeba played crucial roles not only in the formation of phagosome and phagolysosome but also in the digestion of E. coli.

Elucidation of the Molecular Interaction between miRNAs and the HOXA9 Gene, Involved in Acute Myeloid Leukemia, by the Assistance of Argonaute Protein through a Computational Approach

  • Das, Rohit Pritam;Konkimalla, V. Badireenath;Rath, Surya Narayan;Hansa, Jagadish;Jagdeb, Manaswini
    • Genomics & Informatics
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    • v.13 no.2
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    • pp.45-52
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    • 2015
  • Acute myeloid leukemia is a well characterized blood cancer in which the unnatural growth of immature white blood cell takes place, where several genes transcription is regulated by the micro RNAs (miRNAs). Argonaute (AGO) protein is a protein family that binds to the miRNAs and mRNA complex where a strong binding affinity is crucial for its RNA silencing function. By understanding pattern recognition between the miRNAs-mRNA complex and its binding affinity with AGO protein, one can decipher the regulation of a particular gene and develop suitable siRNA for the same in disease condition. In the current work, HOXA9 gene has been selected from literature, whose deregulation is well-established in acute myeloid leukemia. Four miRNAs (mir-145, mir-126, let-7a, and mir-196b) have been selected to target mRNA of HOXA9 (NCBI accession No. NM_152739.3). The binding interaction between mRNAs and mRNA of HOXA9 gene was studied computationally. From result, it was observed mir-145 has highest affinity for HOXA9 gene. Furthermore, the interaction between miRNAs-mRNA duplex of all chosen miRNAs are docked with AGO protein (PDB ID: 3F73, chain A) to study their interaction at molecular level through an in silico approach. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding of AGO-assisted miRNA based gene silencing mechanism in HOXA9 gene associated in acute myeloid leukemia computationally.

Chrysanthemum stunt viroid Induces the Accumulation of Small RNAs Associated with RNA Silencing in Infected Chrysanthemum

  • Chung Bong-Nam;Choi Gug-Seoun;Kim Ki-Taek
    • The Plant Pathology Journal
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    • v.22 no.3
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    • pp.235-238
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    • 2006
  • Chrysanthemum stunt viroid (CSVd) induced systemic symptoms on chrysanthemum. We detected small RNAs of approximately 22 nucleotides with sequence specificity to CSVd in chrysanthemum infected with CSVd: an indication of the presence of RNA silencing. Regardless of symptom differences associated with CSVd, the small RNAs distributed similarly in amount. Small RNAs were detected with partial-length or full-length probes, indicating that they are not restricted to specific viroid regions but likely representing most of the viroid molecule.

The diverse roles of RNA polymerase II C-terminal domain phosphatase SCP1

  • Harikrishna, Reddy R.;Kim, Hackyoung;Noh, Kwangmo;Kim, Young Jun
    • BMB Reports
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    • v.47 no.4
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    • pp.192-196
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    • 2014
  • RNA polymerase II carboxyl-terminal domain (pol II CTD) phosphatases are a newly emerging family of phosphatases that are members of DXDX (T/V). The subfamily includes Small CTD phosphatases, like SCP1, SCP2, SCP3, TIMM50, HSPC129 and UBLCP. Extensive study of SCP1 has elicited the diversified roles of the small C terminal domain phosphatase. The SCP1 plays a vital role in various biological activities, like neuronal gene silencing and preferential Ser5 dephosphorylation, acts as a cardiac hypertrophy inducer with the help of its intronic miRNAs, and has shown a key role in cell cycle regulation. This short review offers an explanation of the mechanism of action of small CTD phosphatases, in different biological activities and metabolic processes.

Rules for functional microRNA targeting

  • Kim, Doyeon;Chang, Hee Ryung;Baek, Daehyun
    • BMB Reports
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    • v.50 no.11
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    • pp.554-559
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    • 2017
  • MicroRNAs (miRNAs) are ~22nt-long single-stranded RNA molecules that form a RNA-induced silencing complex with Argonaute (AGO) protein to post-transcriptionally downregulate their target messenger RNAs (mRNAs). To understand the regulatory mechanisms of miRNA, discovering the underlying functional rules for how miRNAs recognize and repress their target mRNAs is of utmost importance. To determine functional miRNA targeting rules, previous studies extensively utilized various methods including high-throughput biochemical assays and bioinformatics analyses. However, targeting rules reported in one study often fail to be reproduced in other studies and therefore the general rules for functional miRNA targeting remain elusive. In this review, we evaluate previously-reported miRNA targeting rules and discuss the biological impact of the functional miRNAs on gene-regulatory networks as well as the future direction of miRNA targeting research.