• Title/Summary/Keyword: MYC

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Costunolide Induces Differentiation of Human Leukemia HL-60 Cells

  • Choi, Jung-Hye;Seo, Bo-Rim;Seo, Seong-Hoon;Lee, Kyung-Tae;Park, Jae-Hoon;Park, Hee-Juhn;Choi, Jong-Won;Yoshie-Itoh;Miyamoto, Ken-Ichi
    • Archives of Pharmacal Research
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    • v.25 no.4
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    • pp.480-484
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    • 2002
  • Costunolide has been reported to be a cytotoxic and chemopreventive agent. This work investigated the mechanism of the anti proliferative effect of costunolide and determined that it induced differentiation of the human leukemia cell line HL-60. Costunolide exhibited a potent antiproliferative activity against HL-60 cells. It was also found to be a potent inducer of differentiation in human leukemia derived HL-60 cells through the examination of differentiation markers, as assessed by the reduction of nitroblue tetrazolium, the increase in esterase activities and phagocytic activity, morphology change and the expression of CD14 and CD66b surface antigens. These results, accompanied by a decline in the expression of c-myc protein, suggest that costunolide induces differentiation of human leukemia cells to granulocytes and monocytes/macrophages lineage.

Transcriptome analysis of iBET-151, a BET inhibitor alone and in combination with paclitaxel in gastric cancer cells

  • Kang, Sun Kyoung;Bae, Hyun Joo;Kwon, Woo Sun;Che, Jingmin;Kim, Tae Soo;Chung, Hyun Cheol;Rha, Sun Young
    • Genomics & Informatics
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    • v.18 no.4
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    • pp.37.1-37.11
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    • 2020
  • BET inhibitor, as an epigenetic regulator inhibitor, reduces the expression of oncogenes such as Myc and Bcl-2, which affects cancer growth and development. However, it has modest activity because of the narrow therapeutic index. Therefore, combination therapy is necessary to increase the anti-tumor effect. Paclitaxel, an anti-mitotic inhibitor, is used as second-line therapy for gastric cancer (GC) as a monotherapy or combination. In this study, we performed RNA sequencing of GC cells treated with iBET-151 and/or paclitaxel to identify the differentially expressed genes associated with possible mechanisms of synergistic effect. We also performed Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses to determine the most enriched terms and pathways of upregulated and downregulated genes. We found 460 genes in which iBET-151 and paclitaxel combination treatment changed more than single-treatment or no-treatment. Thus, additional functional studies are needed, but our results provide the first evidence of the synergistic effect between iBET-151 and paclitaxel in regulating the transcriptome of GC cells.

Intraoral HIV-associated Burkitt's lymphoma: a rare case report with special emphasis on differential diagnosis

  • Kamat, Mamata;Datar, Uma;Kanitkar, Sampada;Byakodi, Sanjay
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.45 no.4
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    • pp.225-229
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    • 2019
  • Individuals with human immunodeficiency virus (HIV) infection present with unique intraoral manifestations of various neoplasms. Intraoral HIV-associated Burkitt's lymphoma is a rare presentation, especially in patients of Indian origin and may present as an initial sign of HIV. The objective of this paper is to report a rare case of Burkitt's lymphoma in an HIV-positive Indian patient along with a special emphasis on differential diagnosis. A 30-year-old Indian female presented with a solitary, well-defined, exophytic mass extending anteroposteriorly and buccolingually from the 35th to 38th regions with no evidence of intraosseous extension. An incisional biopsy was performed, and histopathology showed sheets of neoplastic lymphoid cells with numerous tingible body macrophages with clear cytoplasm, presenting a starry sky appearance, suggesting a diagnosis of BL. The tumor cells were positive for CD10, CD20, c-myc, and Epstein-Barr virus, with a nearly 100% Ki-67 proliferative index. The patient tested positive for HIV. This report indicates the importance of immunohistochemical analysis to differentiate Burkitt's lymphoma from other similar lesions like diffuse large B-cell lymphoma. Thorough knowledge of the clinical presentation, etiopathogenesis, histopathology, and immunoprofile of intraoral HIV-associated Burkitt's lymphoma is essential among clinicians and pathologists.

Hypermethylation-mediated silencing of NDRG4 promotes pancreatic ductal adenocarcinoma by regulating mitochondrial function

  • Shi, Hao-Hong;Liu, Hai-E;Luo, Xing-Jing
    • BMB Reports
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    • v.53 no.12
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    • pp.658-663
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    • 2020
  • The N-myc downstream regulated gene (NDRG) family members are dysregulated in several tumors. Functionally, NDRGs play an important role in the malignant progression of cancer cells. However, little is known about the potential implications of NDRG4 in pancreatic ductal adenocarcinoma (PDAC). The aim of the current study was to elucidate the expression pattern of NDRG4 in PDAC and evaluate its potential cellular biological effects. Here, we firstly report that epigenetic-mediated silencing of NDRG4 promotes PDAC by regulating mitochondrial function. Data mining demonstrated that NDRG4 was significantly down-regulated in PDAC tissues and cells. PDAC patients with low NDRG4 expression showed poor prognosis. Epigenetic regulation by DNA methylation was closely associated with NDRG4 down-regulation. NDRG4 overexpression dramatically suppressed PDAC cell growth and metastasis. Further functional analysis demonstrated that up-regulated NDRG4 in SW1990 and Canpan1 cells resulted in attenuated mitochondrial function, including reduced ATP production, decreased mitochondrial membrane potential, and increased fragmented mitochondria. However, opposite results were obtained for HPNE cells with NDRG4 knockdown. These results indicate that hypermethylation-driven silencing of NDRG4 can promote PDAC by regulating mitochondrial function and that NDRG4 could be as a potential biomarker for PDAC patients.

Melatonin inhibits glycolysis in hepatocellular carcinoma cells by downregulating mitochondrial respiration and mTORC1 activity

  • Lee, Seunghyeong;Byun, Jun-Kyu;Kim, Na-Young;Jin, Jonghwa;Woo, Hyein;Choi, Yeon-Kyung;Park, Keun-Gyu
    • BMB Reports
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    • v.55 no.9
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    • pp.459-464
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    • 2022
  • Various mechanisms have been suggested to explain the chemopreventive and tumor-inhibitory effects of melatonin. Despite the growing evidence supporting melatonin-induced mitochondrial dysfunction, it remains largely unknown how this phenomenon modulates metabolic reprogramming in cancer cells. The aim of our study was to identify the mechanism underlying the anti-proliferative and apoptotic effects of melatonin, which is known to inhibit glycolysis. We analyzed the time-dependent effects of melatonin on mitochondrial respiration and glycolysis in liver cancer cells. The results showed that from a cell bioenergetic point of view, melatonin caused an acute reduction in mitochondrial respiration, however, increased reactive oxygen species production, thereby inhibiting mTORC1 activity from an early stage post-treatment without affecting glycolysis. Nevertheless, administration of melatonin for a longer time reduced expression of c-Myc protein, thereby suppressing glycolysis via downregulation of HK2 and LDHA. The data presented herein suggest that melatonin suppresses mitochondrial respiration and glycolysis simultaneously in HCC cells, leading to anti-cancer effects. Thus, melatonin can be used as an adjuvant agent for therapy of liver cancer.

CKD-581 Downregulates Wnt/β-Catenin Pathway by DACT3 Induction in Hematologic Malignancy

  • Kim, Soo Jin;Kim, Suntae;Choi, Yong June;Kim, U Ji;Kang, Keon Wook
    • Biomolecules & Therapeutics
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    • v.30 no.5
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    • pp.435-446
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    • 2022
  • The present study evaluated the anti-cancer activity of histone deacetylase (HDAC)-inhibiting CKD-581 in multiple myeloma (MM) and its pharmacological mechanisms. CKD-581 potently inhibited a broad spectrum of HDAC isozymes. It concentration-dependently inhibited proliferation of hematologic cancer cells including MM (MM.1S and RPMI8226) and T cell lymphoma (HH and MJ). It increased the expression of the dishevelled binding antagonist of β-catenin 3 (DACT3) in T cell lymphoma and MM cells, and decreased the expression of c-Myc and β-catenin in MM cells. Additionally, it enhanced phosphorylated p53, p21, cleaved caspase-3 and the subG1 population, and reversely, downregulated cyclin D1, CDK4 and the anti-apoptotic BCL-2 family. Finally, administration of CKD-581 exerted a significant anti-cancer activity in MM.1S-implanted xenografts. Overall, CKD-581 shows anticancer activity via inhibition of the Wnt/β-catenin signaling pathway in hematologic malignancies. This finding is evidence of the therapeutic potential and rationale of CKD-581 for treatment of MM.

Kinesin-13, a Motor Protein, is Regulated by Polo-like Kinase in Giardia lamblia

  • Park, Eun-Ah;Kim, Juri;Shin, Mee Young;Park, Soon-Jung
    • Parasites, Hosts and Diseases
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    • v.60 no.3
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    • pp.163-172
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    • 2022
  • Kinesin-13 (Kin-13), a depolymerizer of microtubule (MT), has been known to affect the length of Giardia. Giardia Kin-13 (GlKin-13) was localized to axoneme, flagellar tips, and centrosomes, where phosphorylated forms of Giardia polo-like kinase (GlPLK) were distributed. We observed the interaction between GlKin-13 and GlPLK via co-immunoprecipitation using transgenic Giardia cells expressing Myc-tagged GlKin-13, hemagglutinin-tagged GlPLK, and in vitro-synthesized GlKin-13 and GlPLK proteins. In vitro-synthesized GlPLK was demonstrated to auto-phosphorylate and phosphorylate GlKin-13 upon incubation with [γ-32P]ATP. Morpholino-mediated depletion of both GlKin-13 and GlPLK caused an extension of flagella and a decreased volume of median bodies in Giardia trophozoites. Our results suggest that GlPLK plays a pertinent role in formation of flagella and median bodies by modulating MT depolymerizing activity of GlKin-13.

Mycobacterial Infection among Retired Dusty Workers Ineligible for Medical Care Benefits for Work-related Pneumoconiosis (요양 비대상인 분진작업 이직근로자에서 마이코박테리아 감염)

  • Joo Hwan Hwang
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.33 no.3
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    • pp.355-364
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    • 2023
  • Objectives: The objective of the present study was to identify mycobacterial infection in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis. Methods: Sputum samples were collected from 170 retired dusty workers living in Gangwon-do. The mycobacterial culture was grown in 2% Ogawa medium and Mycobacteria Growth Indicator Tube(MGIT). Mycobacterial species were identified using MolecuTech REBA Myco-ID. Results: Thirty-one(18.2%) out of 170 sputum samples were identified as positive for culture. Among the positive culture samples, eleven(6.5%) were identified as mycobacterial species. The proportion of mycobacteria was M. avium 2.3%(4/170), M. fortuitum complex 1.2%(2/170), M. intracellulare 1.2%(2/170), M. abscessus 0.6%(1/170), M. tuberculosis(MTB) complex 0.6%(1/170), and MYC(NTM except 19 species) 0.6%(1/170). Conclusions: In comparison with previous studies, the incidence rate of tuberculosis(TB) in retired dusty workers who were ineligible for medical care benefits for work-related pneumoconiosis was higher than in close contact with TB patients, workers exposed to silica, and patients with silicosis. And the proportion of non-tuberculosis mycobacteria(NTM) was higher than that of MTB.

Backbone Cyclization of Flavin Mononucleotide-Based Fluorescent Protein Increases Fluorescence and Stability

  • Tingting Lin;Yuanyuan Ge;Qing Gao;Di Zhang;Xiaofeng Chen;Yafang Hu;Jun Fan
    • Journal of Microbiology and Biotechnology
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    • v.33 no.12
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    • pp.1681-1691
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    • 2023
  • Flavin mononucleotide-binding proteins or domains emit cyan-green fluorescence under aerobic and anaerobic conditions, but relatively low fluorescence and less thermostability limit their application as reporters. In this work, we incorporated the codon-optimized fluorescent protein from Chlamydomonas reinhardtii with two different linkers independently into the redox-responsive split intein construct, overexpressed the precursors in hyperoxic Escherichia coli SHuffle T7 strain, and cyclized the target proteins in vitro in the presence of the reducing agent. Compared with the purified linear protein, the cyclic protein with the short linker displayed enhanced fluorescence. In contrast, cyclized protein with incorporation of the long linker including the myc-tag and human rhinovirus 3C protease cleavable sequence emitted slightly increased fluorescence compared with the protein linearized with the protease cleavage. The cyclic protein with the short linker also exhibited increased thermal stability and exopeptidase resistance. Moreover, induction of the target proteins in an oxygen-deficient culture rendered fluorescent E. coli BL21 (DE3) cells brighter than those overexpressing the linear construct. Thus, the cyclic reporter can hopefully be used in certain thermophilic anaerobes.

Overexpression of Hypermethylated Homeobox A11 (HOXA11) Inhibits Tumor Cell Growth and Induces Apoptosis in Cervical Cancer

  • Seung-Yul Lee;Tae Jeong Oh;Sungwhan An;Seung-Hoon Lee
    • Development and Reproduction
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    • v.28 no.2
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    • pp.37-45
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    • 2024
  • This study aimed to elucidate the potential of Homeobox A11 (HOXA11) as a therapeutic target and a diagnostic methylation marker for cervical cancer. Gene expression analysis using cDNA microarray in cervical cancer cell lines revealed significantly reduced expression of the HOXA11 gene. Subsequent investigation of HOXA11 promoter methylation in samples from normal individuals and invasive cervical cancer patients showed over 53.2% higher methylation in cancer scrapes compared to normal scrapes. Furthermore, overexpression of HOXA11, which is downregulated in cervical cancer, strongly suppressed cell growth in cervical cancer cell lines, HeLa and HT3. Additionally, we performed transferase dUTP nick end labeling assay and confirmed that the inhibition of cervical cancer cell proliferation occurred via apoptosis. Mechanistically, overexpression of HOXA11 led to mitochondrial apoptosis characterized by PARP cleavage due to increased c-Myc and enhanced cytochrome C secretion into the cytoplasm. These findings suggest that HOXA11 could potentially serve as a methylation marker for diagnosing cervical cancer and as a novel therapeutic target for its treatment.