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1.
Proc Natl Acad Sci U S A ; 117(50): 31993-32004, 2020 12 15.
Article in English | MEDLINE | ID: mdl-33262282

ABSTRACT

Effective cancer prevention requires the discovery and intervention of a factor critical to cancer development. Here we show that ovarian progesterone is a crucial endogenous factor inducing the development of primary tumors progressing to metastatic ovarian cancer in a mouse model of high-grade serous carcinoma (HGSC), the most common and deadliest ovarian cancer type. Blocking progesterone signaling by the pharmacologic inhibitor mifepristone or by genetic deletion of the progesterone receptor (PR) effectively suppressed HGSC development and its peritoneal metastases. Strikingly, mifepristone treatment profoundly improved mouse survival (∼18 human years). Hence, targeting progesterone/PR signaling could offer an effective chemopreventive strategy, particularly in high-risk populations of women carrying a deleterious mutation in the BRCA gene.


Subject(s)
BRCA1 Protein/genetics , Cystadenocarcinoma, Serous/prevention & control , Mifepristone/pharmacology , Ovarian Neoplasms/prevention & control , Progesterone/antagonists & inhibitors , Adult , Animals , Breast/pathology , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Breast Neoplasms/prevention & control , Cystadenocarcinoma, Serous/chemistry , Cystadenocarcinoma, Serous/genetics , Cystadenocarcinoma, Serous/pathology , Disease Models, Animal , Estradiol/administration & dosage , Female , Humans , Mice , Middle Aged , Mifepristone/therapeutic use , Mutation , Neoplasms, Experimental/chemically induced , Neoplasms, Experimental/genetics , Neoplasms, Experimental/pathology , Neoplasms, Experimental/prevention & control , Ovarian Neoplasms/chemically induced , Ovarian Neoplasms/genetics , Ovarian Neoplasms/pathology , Ovary/pathology , Ovary/surgery , Progesterone/administration & dosage , Progesterone/metabolism , Receptors, Progesterone/genetics , Receptors, Progesterone/metabolism , Salpingo-oophorectomy , Signal Transduction/drug effects , Signal Transduction/genetics
2.
PLoS Genet ; 16(6): e1008808, 2020 06.
Article in English | MEDLINE | ID: mdl-32497036

ABSTRACT

Metastasis is responsible for 90% of human cancer mortality, yet it remains a challenge to model human cancer metastasis in vivo. Here we describe mouse models of high-grade serous ovarian cancer, also known as high-grade serous carcinoma (HGSC), the most common and deadliest human ovarian cancer type. Mice genetically engineered to harbor Dicer1 and Pten inactivation and mutant p53 robustly replicate the peritoneal metastases of human HGSC with complete penetrance. Arising from the fallopian tube, tumors spread to the ovary and metastasize throughout the pelvic and peritoneal cavities, invariably inducing hemorrhagic ascites. Widespread and abundant peritoneal metastases ultimately cause mouse deaths (100%). Besides the phenotypic and histopathological similarities, mouse HGSCs also display marked chromosomal instability, impaired DNA repair, and chemosensitivity. Faithfully recapitulating the clinical metastases as well as molecular and genomic features of human HGSC, this murine model will be valuable for elucidating the mechanisms underlying the development and progression of metastatic ovarian cancer and also for evaluating potential therapies.


Subject(s)
Antineoplastic Agents/pharmacology , Cystadenocarcinoma, Serous/genetics , Ovarian Neoplasms/pathology , Peritoneal Neoplasms/genetics , Animals , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Chromosomal Instability , Cystadenocarcinoma, Serous/drug therapy , Cystadenocarcinoma, Serous/secondary , DEAD-box RNA Helicases/genetics , DNA Repair , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Drug Screening Assays, Antitumor/methods , Feasibility Studies , Female , Humans , Mice , Mice, Knockout , Mutation , Neoplasm Grading , Neoplasm Metastasis/genetics , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , PTEN Phosphohydrolase/genetics , Peritoneal Neoplasms/drug therapy , Peritoneal Neoplasms/secondary , Primary Cell Culture , Ribonuclease III/genetics , Tumor Suppressor Protein p53/genetics
3.
J Inequal Appl ; 2017(1): 188, 2017.
Article in English | MEDLINE | ID: mdl-28860689

ABSTRACT

In this paper, we investigate the optimal consumption and portfolio selection problem with negative wealth constraints for an economic agent who has a quadratic utility function of consumption and receives a constant labor income. Due to the property of the quadratic utility function, we separate our problem into two cases and derive the closed-form solutions for each case. We also illustrate some numerical implications of the optimal consumption and portfolio.

4.
J Clin Invest ; 127(6): 2106-2117, 2017 Jun 01.
Article in English | MEDLINE | ID: mdl-28504655

ABSTRACT

Following migration of primordial germ cells to the genital ridge, oogonia undergo several rounds of mitotic division and enter meiosis at approximately E13.5. Most oocytes arrest in the dictyate (diplotene) stage of meiosis circa E18.5. The genes necessary to drive oocyte differentiation in parallel with meiosis are unknown. Here, we have investigated whether expression of spermatogenesis and oogenesis bHLH transcription factor 1 (Sohlh1) and Sohlh2 coordinates oocyte differentiation within the embryonic ovary. We found that SOHLH2 protein was expressed in the mouse germline as early as E12.5 and preceded SOHLH1 protein expression, which occurred circa E15.5. SOHLH1 protein appearance at E15.5 correlated with SOHLH2 translocation from the cytoplasm into the nucleus and was dependent on SOHLH1 expression. NOBOX oogenesis homeobox (NOBOX) and LIM homeobox protein 8 (LHX8), two important regulators of postnatal oogenesis, were coexpressed with SOHLH1. Single deficiency of Sohlh1 or Sohlh2 disrupted the expression of LHX8 and NOBOX in the embryonic gonad without affecting meiosis. Sohlh1-KO infertility was rescued by conditional expression of the Sohlh1 transgene after the onset of meiosis. However, Sohlh1 or Sohlh2 transgene expression could not rescue Sohlh2-KO infertility due to a lack of Sohlh1 or Sohlh2 expression in rescued mice. Our results indicate that Sohlh1 and Sohlh2 are essential regulators of oocyte differentiation but do not affect meiosis I.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/physiology , Meiosis , Oocytes/physiology , Active Transport, Cell Nucleus , Animals , Cell Differentiation , Cell Proliferation , Cells, Cultured , Embryonic Development , Female , Gene Expression , Homeodomain Proteins/metabolism , Male , Mice, Transgenic , Promoter Regions, Genetic , Sex Characteristics , Transcription Factors/metabolism , Transcriptional Activation
5.
J Clin Invest ; 125(8): 3280-4, 2015 Aug 03.
Article in English | MEDLINE | ID: mdl-26193636

ABSTRACT

Uterine leiomyomas are benign tumors that can cause pain, bleeding, and infertility in some women. Mediator complex subunit 12 (MED12) exon 2 variants are associated with uterine leiomyomas; however, the causality of MED12 variants, their genetic mode of action, and their role in genomic instability have not been established. Here, we generated a mouse model that conditionally expresses a Med12 missense variant (c.131G>A) in the uterus and demonstrated that this alteration alone promotes uterine leiomyoma formation and hyperplasia in both WT mice and animals harboring a uterine mesenchymal cell-specific Med12 deletion. Compared with WT animals, expression of Med12 c.131G>A in conditional Med12-KO mice resulted in earlier onset of leiomyoma lesions that were also greater in size. Moreover, leiomyomatous, Med12 c.131G>A variant-expressing uteri developed chromosomal rearrangements. Together, our results show that the common human leiomyoma-associated MED12 variant can cause leiomyomas in mice via a gain of function that drives genomic instability, which is frequently observed in human leiomyomas.


Subject(s)
Genomic Instability , Leiomyoma/metabolism , Mediator Complex/metabolism , Mutation, Missense , Neoplasm Proteins/metabolism , Neoplasms, Experimental/metabolism , Amino Acid Substitution , Animals , Chromosome Aberrations , Female , Humans , Leiomyoma/genetics , Leiomyoma/pathology , Mediator Complex/genetics , Mice , Mice, Transgenic , Neoplasm Proteins/genetics , Neoplasms, Experimental/genetics , Neoplasms, Experimental/pathology
6.
Biol Reprod ; 89(2): 29, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23759310

ABSTRACT

Oocytes in embryonic ovaries enter meiosis I and arrest in the diplonema stage. Perturbations in meiosis I, such as abnormal double-strand break (DSB) formation and repair, adversely affect oocyte survival. We previously discovered that HORMAD1 is a critical component of the synaptonemal complex but not essential for oocyte survival. No significant differences were observed in the number of primordial, primary, secondary, and developing follicles between wild-type and Hormad1(−/−)newborn, 8-day, and 80-day ovaries. Meiosis I progression in Hormad1(−/−) embryonic ovaries was normal through the zygotene stage and in oocytes arrested in diplonema; however, we did not visualize oocytes with completely synapsed chromosomes. We investigated effects of HORMAD1 deficiency on the kinetics of DNA DSB formation and repair in the mouse ovary. We irradiated Embryonic Day 16.5 wild-type and Hormad1(−/−) ovaries and monitored DSB repair using gammaH2AX, RAD51, and DMC1 immunofluorescence. Our results showed a significant drop in unrepaired DSBs in the irradiated Hormad1(−/−) zygotene oocytes as compared to the wild-type oocytes. Moreover, Hormad1 deficiency rescued Dmc1(−/−) oocytes. These results indicate that Hormad1 deficiency promotes DMC1-independent DSB repairs, which in turn helps asynaptic Hormad1(−/−) oocytes resist perinatal loss.


Subject(s)
Cell Cycle Proteins/metabolism , DNA Breaks, Double-Stranded , DNA Repair/genetics , Meiosis/genetics , Animals , Cell Cycle Checkpoints/genetics , Cell Cycle Proteins/genetics , Female , Mice , Mice, Knockout , Oocytes/metabolism
7.
Cancer Lett ; 330(2): 123-9, 2013 Apr 28.
Article in English | MEDLINE | ID: mdl-22776561

ABSTRACT

The present study was undertaken to determine the expression and biological significance of HORMAD1 in human epithelial ovarian carcinoma. We found that a substantial proportion of human epithelial ovarian cancers expressed HORMAD1. In vitro, HORMAD1 siRNA enhanced docetaxel induced apoptosis and substantially reduced the invasive and migratory potential of ovarian cancer cells (2774). In vivo, HORMAD1 siRNA-DOPC treatment resulted in reduced tumor weight, which was further enhanced in combination with cisplatin. HORMAD1 gene silencing resulted in significantly reduced VEGF protein levels and microvessel density compared to controls. Our data suggest that HORMAD1 may be an important therapeutic target.


Subject(s)
Cell Cycle Proteins/physiology , Neoplasms, Glandular and Epithelial/metabolism , Neoplasms, Glandular and Epithelial/pathology , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Animals , Carcinoma, Ovarian Epithelial , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/genetics , Cell Line, Tumor , Female , Humans , Mice , Neoplasm Invasiveness , Neoplasms, Glandular and Epithelial/genetics , Ovarian Neoplasms/genetics , RNA, Messenger/analysis , RNA, Small Interfering/genetics , Tumor Microenvironment , Vascular Endothelial Growth Factor A/analysis , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism
8.
Blood Research ; : 24-30, 2013.
Article in English | WPRIM (Western Pacific) | ID: wpr-132585

ABSTRACT

BACKGROUND: Only a few patients who experience AML relapse derive lasting benefit from re-induction therapy. The utility of reassessing the disease karyotype at relapse is unclear. The main goals of this study were to identify prognostic factors for AML relapse and to determine the prognostic utility of karyotypic change between diagnosis and relapse as a variable for predicting response to salvage therapy for relapsed AML. METHODS: This retrospective study included 58 patients with relapsed AML treated at the Yonsei University College of Medicine between 2005 and 2010. Karyotypes at both diagnosis and relapse were available for 45 patients (77%). A change in karyotype at relapse was observed in 17 of 45 cases (37%), and no change was noted in 28 of 45 cases (62%). RESULTS: Karyotypic changes between diagnosis and relapse were associated with the response rate (RR) to salvage therapy (P=0.016). Overall survival (OS) and event-free survival (EFS) in the group with karyotypic changes between diagnosis and relapse were significantly different from those with no karyotypic changes (P=0.004 and P=0.010, respectively). We applied multiple multivariate Cox regression analyses to identify independent prognostic factors for overall response (OR), OS, and EFS. A change in karyotype between diagnosis and relapse was significantly associated with OS (P=0.023; RR=2.655) and EFS (P=0.033; RR=2.831). CONCLUSION: Karyotypic changes between the diagnosis and relapse of AML could be used to predict outcomes and tailor clinical and biological therapeutic strategies for relapsed AML patients.


Subject(s)
Humans , Disease-Free Survival , Karyotype , Leukemia, Myeloid, Acute , Prognosis , Recurrence , Retrospective Studies , Salvage Therapy
9.
Blood Research ; : 24-30, 2013.
Article in English | WPRIM (Western Pacific) | ID: wpr-132580

ABSTRACT

BACKGROUND: Only a few patients who experience AML relapse derive lasting benefit from re-induction therapy. The utility of reassessing the disease karyotype at relapse is unclear. The main goals of this study were to identify prognostic factors for AML relapse and to determine the prognostic utility of karyotypic change between diagnosis and relapse as a variable for predicting response to salvage therapy for relapsed AML. METHODS: This retrospective study included 58 patients with relapsed AML treated at the Yonsei University College of Medicine between 2005 and 2010. Karyotypes at both diagnosis and relapse were available for 45 patients (77%). A change in karyotype at relapse was observed in 17 of 45 cases (37%), and no change was noted in 28 of 45 cases (62%). RESULTS: Karyotypic changes between diagnosis and relapse were associated with the response rate (RR) to salvage therapy (P=0.016). Overall survival (OS) and event-free survival (EFS) in the group with karyotypic changes between diagnosis and relapse were significantly different from those with no karyotypic changes (P=0.004 and P=0.010, respectively). We applied multiple multivariate Cox regression analyses to identify independent prognostic factors for overall response (OR), OS, and EFS. A change in karyotype between diagnosis and relapse was significantly associated with OS (P=0.023; RR=2.655) and EFS (P=0.033; RR=2.831). CONCLUSION: Karyotypic changes between the diagnosis and relapse of AML could be used to predict outcomes and tailor clinical and biological therapeutic strategies for relapsed AML patients.


Subject(s)
Humans , Disease-Free Survival , Karyotype , Leukemia, Myeloid, Acute , Prognosis , Recurrence , Retrospective Studies , Salvage Therapy
10.
PLoS Genet ; 6(11): e1001190, 2010 Nov 04.
Article in English | MEDLINE | ID: mdl-21079677

ABSTRACT

Meiosis is unique to germ cells and essential for reproduction. During the first meiotic division, homologous chromosomes pair, recombine, and form chiasmata. The homologues connect via axial elements and numerous transverse filaments to form the synaptonemal complex. The synaptonemal complex is a critical component for chromosome pairing, segregation, and recombination. We previously identified a novel germ cell-specific HORMA domain encoding gene, Hormad1, a member of the synaptonemal complex and a mammalian counterpart to the yeast meiotic HORMA domain protein Hop1. Hormad1 is essential for mammalian gametogenesis as knockout male and female mice are infertile. Hormad1 deficient (Hormad1(-/) (-)) testes exhibit meiotic arrest in the early pachytene stage, and synaptonemal complexes cannot be visualized by electron microscopy. Hormad1 deficiency does not affect localization of other synaptonemal complex proteins, SYCP2 and SYCP3, but disrupts homologous chromosome pairing. Double stranded break formation and early recombination events are disrupted in Hormad1(-/) (-) testes and ovaries as shown by the drastic decrease in the γH2AX, DMC1, RAD51, and RPA foci. HORMAD1 co-localizes with γH2AX to the sex body during pachytene. BRCA1, ATR, and γH2AX co-localize to the sex body and participate in meiotic sex chromosome inactivation and transcriptional silencing. Hormad1 deficiency abolishes γH2AX, ATR, and BRCA1 localization to the sex chromosomes and causes transcriptional de-repression on the X chromosome. Unlike testes, Hormad1(-/) (-) ovaries have seemingly normal ovarian folliculogenesis after puberty. However, embryos generated from Hormad1(-/) (-) oocytes are hyper- and hypodiploid at the 2 cell and 8 cell stage, and they arrest at the blastocyst stage. HORMAD1 is therefore a critical component of the synaptonemal complex that affects synapsis, recombination, and meiotic sex chromosome inactivation and transcriptional silencing.


Subject(s)
Cell Cycle Proteins/genetics , Chromosome Segregation/genetics , Meiosis/genetics , Mutation/genetics , Recombination, Genetic/genetics , Synaptonemal Complex/metabolism , Aneuploidy , Animals , Ataxia Telangiectasia Mutated Proteins , Cell Cycle Proteins/metabolism , DNA-Binding Proteins/metabolism , Embryonic Development/genetics , Female , Fetus/cytology , Fetus/metabolism , Male , Mice , Nuclear Proteins/metabolism , Oocytes/cytology , Oocytes/metabolism , Organ Specificity/genetics , Ovary/growth & development , Ovary/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Protein Transport , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sex Chromosomes/genetics , Spermatogenesis/genetics , Spermatozoa/cytology , Spermatozoa/metabolism , Spermatozoa/ultrastructure , Synaptonemal Complex/ultrastructure , Tumor Suppressor Proteins/metabolism
11.
PLoS One ; 5(11): e14005, 2010 Nov 16.
Article in English | MEDLINE | ID: mdl-21103374

ABSTRACT

FTO (fat mass and obesity associated) was identified as an obesity-susceptibility gene by several independent large-scale genome association studies. A cluster of SNPs (single nucleotide polymorphism) located in the first intron of FTO was found to be significantly associated with obesity-related traits, such as body mass index, hip circumference, and body weight. FTO encodes a protein with a novel C-terminal α-helical domain and an N-terminal double-strand ß-helix domain which is conserved in Fe(II) and 2-oxoglutarate-dependent oxygenase family. In vitro, FTO protein can demethylate single-stranded DNA or RNA with a preference for 3-methylthymine or 3-methyluracil. Its physiological substrates and function, however, remain to be defined. Here we report the generation and analysis of mice carrying a conditional deletion allele of Fto. Our results demonstrate that Fto plays an essential role in postnatal growth. The mice lacking Fto completely display immediate postnatal growth retardation with shorter body length, lower body weight, and lower bone mineral density than control mice, but their body compositions are relatively normal. Consistent with the growth retardation, the Fto mutant mice have reduced serum levels of IGF-1. Moreover, despite the ubiquitous expression of Fto, its specific deletion in the nervous system results in similar phenotypes as the whole body deletion, indicating that Fto functions in the central nerve system to regulate postnatal growth.


Subject(s)
Body Weight/genetics , Brain/metabolism , Gene Expression Regulation, Developmental , Proteins/genetics , Alpha-Ketoglutarate-Dependent Dioxygenase FTO , Animals , Blotting, Western , Body Weight/physiology , Bone Density/physiology , Brain/growth & development , Dietary Fats/administration & dosage , Female , Genetic Predisposition to Disease , Growth Disorders/genetics , Growth Disorders/metabolism , Growth Disorders/physiopathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Obesity/etiology , Obesity/genetics , Obesity/physiopathology , Proteins/metabolism , Proteins/physiology , Reverse Transcriptase Polymerase Chain Reaction
12.
Nat Cell Biol ; 10(9): 1083-9, 2008 Sep.
Article in English | MEDLINE | ID: mdl-19160489

ABSTRACT

The anaphase promoting complex (APC) or cyclosome is a multisubunit E3 ubiquitin ligase. Cdc20 (fizzy (fzy)) or p55CDC, and Cdh1 (Hct1, srw1 or fizzy-related 1 (fzr1)) encode two adaptor proteins that bring substrates to the APC. Both APC-Cdc20 and APC-Cdh1 have been implicated in the control of mitosis through mediating ubiquitination of mitotic regulators, such as cyclin B1 and securin. However, the importance of Cdh1 function in vivo and whether its function is redundant with that of Cdc20 are unclear. Here we have analysed mice lacking Cdh1. We show that Cdh1 is essential for placental development and that its deficiency causes early lethality. Cdhl-deficient mouse embryonic fibroblasts (MEFs) entered replicative senescence prematurely because of stabilization of Ets2 and subsequent activation of p6(Ink4a) expression. These results have uncovered an unexpected role of the APC in maintaining replicative lifespan of MEFs. Further, Cdh1 heterozygous mice show defects in late-phase long-term potentiation (L-LTP) in the hippocampus and are deficient in contextual fear-conditioning, suggesting that Cdh1 has a role in learning and memory.


Subject(s)
Cell Cycle Proteins/metabolism , Cellular Senescence , Memory/physiology , Ubiquitin-Protein Ligase Complexes/metabolism , Anaphase-Promoting Complex-Cyclosome , Animals , Cdh1 Proteins , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Embryo Loss/metabolism , Fibroblasts/enzymology , Fibroblasts/pathology , Heterozygote , In Vitro Techniques , Mice , Protein Stability , Proto-Oncogene Protein c-ets-2/metabolism , Substrate Specificity
13.
Biochim Biophys Acta ; 1769(3): 204-8, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17368823

ABSTRACT

Expression of CCL23 is induced by external stimuli including PMA in monocytes, but its transcriptional regulation has not been studied to date. Serial deletion analysis of its 5' flanking region revealed that the region -293 to +31 was important for induction by PMA. Cis-acting elements at the -269/-264 (NFAT site), -167/-159 (NF-kappaB site), and -51/-43 (AP-1 site) positions were identified as the critical sites for the CCL23 expression in U937 cells. We demonstrated the binding of the transcription factors to the consensus sites. Specific inhibitors for signal pathways reduced PMA-induced expression of CCL23, confirming involvement of these transcription factors.


Subject(s)
Chemokines, CC/genetics , Gene Expression Regulation , Monocytes/physiology , Promoter Regions, Genetic/genetics , Base Sequence , Binding Sites , Carcinogens/pharmacology , Cells, Cultured/drug effects , Cells, Cultured/metabolism , Chemokines, CC/metabolism , Humans , Molecular Sequence Data , Monocytes/cytology , Monocytes/drug effects , NF-kappa B/genetics , NF-kappa B/metabolism , NFATC Transcription Factors/metabolism , Protein Binding , Regulatory Sequences, Nucleic Acid , Tetradecanoylphorbol Acetate/pharmacology , Transcription Factor AP-1/metabolism , Transcription, Genetic , U937 Cells
14.
Biochim Biophys Acta ; 1732(1-3): 38-42, 2005 Dec 30.
Article in English | MEDLINE | ID: mdl-16364464

ABSTRACT

CCL15 exerts biological effects on a variety of cells, including monocytes. NF-kappaB has been reported to be involved in the transcription of the CCL15 gene. In this study, we have identified an AP-1 element located at -76/-65, which appears to regulate the transcription of the CCL15 gene. We also confirmed that the AP-1 factor binds to the element. Specific inhibitors for MAPK pathways and expression of dominant negative MKK4 or JNK1 reduced PMA-induced transcriptional activation of CCL15. Our findings indicate that transcription of the CCL15 gene is regulated by AP-1 and NF-kappaB through MEK and JNK MAPK pathways in monocytoid cells.


Subject(s)
Chemokines, CC/genetics , Gene Expression Regulation/drug effects , Monocytes/metabolism , Monokines/genetics , NF-kappa B/metabolism , Response Elements/genetics , Transcription Factor AP-1/metabolism , Transcription, Genetic/drug effects , Humans , Macrophage Inflammatory Proteins , Monocytes/drug effects , Point Mutation/genetics , Promoter Regions, Genetic/drug effects , Protein Binding , Signal Transduction/drug effects , Tetradecanoylphorbol Acetate/pharmacology , U937 Cells
15.
Mol Cells ; 20(1): 105-11, 2005 Aug 31.
Article in English | MEDLINE | ID: mdl-16258248

ABSTRACT

Mannasantin B, a dilignan structurally related to manssantin A, is an inhibitor of NF-kappaB transactivation. In the present study, we found that it inhibited PMA-induced expression of IL-1beta, IL-1beta mRNA, and IL-1beta promoter activity in U937 cells with IC50 values of about 50 nM. It also inhibited NF-IL6- and NF-kappaB-induced activation of IL-1beta, with IC50 values of 78 nM and 1.6 microM, respectively, revealing a potent inhibitory effect on NF-IL6. Electrophoretic mobility shift assays showed that manassantin B had an inhibitory effect on DNA binding by NF-IL6, but not by NF-kappaB. Further analysis revealed that transactivation by NF-IL6 was also inhibited. Our results indicate that manassantin B suppresses expression of IL-1beta in promonocytic cells by inhibiting not only NF-kappaB but also NF-IL6 activity. Furthermore, our observations suggest that manassantin B may be clinically useful as a potent inhibitor of NF-IL6 activity.


Subject(s)
CCAAT-Enhancer-Binding Protein-beta/metabolism , Furans/pharmacology , Saururaceae/metabolism , Tetradecanoylphorbol Acetate/antagonists & inhibitors , Dose-Response Relationship, Drug , Electrophoretic Mobility Shift Assay , Humans , Inhibitory Concentration 50 , Interleukin-1/genetics , Interleukin-1/metabolism , Saururaceae/genetics , Saururaceae/immunology , Transcriptional Activation/drug effects , Transfection , U937 Cells
16.
Biochem Biophys Res Commun ; 324(2): 768-72, 2004 Nov 12.
Article in English | MEDLINE | ID: mdl-15474493

ABSTRACT

Multiple CC chemokines bind to CCR1, which plays important roles in immune and inflammatory responses. To search for proteins involved in the CCR1 signaling pathway, we screened a yeast two-hybrid library using the cytoplasmic tail of CCR1 as the bait. One of the positive clones contained an open reading frame of 456bp, of which the nucleotide sequence was identical to that of proteolipid protein 2 (PLP2), also known as protein A4. Mammalian two-hybrid and coimmunoprecipitation analyses demonstrated the association of PLP2/A4 with CCR1. Indirect immunofluorescence analysis revealed that PLP2/A4 was predominantly located in plasma membrane and colocalized with CCR1 in transfected human HEK293 cells. In addition, focal staining of CCR1 appeared on the periphery of the membrane upon short exposure to Leukotactin-1(Lkn-1)/CCL15, a CCR1 agonist, and was costained with PLP2/A4 on the focal regions. PLP2/A4 mRNAs were detected in various cells such as U-937, HL-60, HEK293, and HOS cells. Overexpression of PLP2/A4 stimulated a twofold increase in the agonist-induced migration of HOS/CCR1 cells, implicating a functional role for PLP2/A4 in the chemotactic processes via CCR1.


Subject(s)
Membrane Proteins/chemistry , Protein Serine-Threonine Kinases/metabolism , Amino Acid Sequence , Blotting, Western , Cell Line , Cell Line, Tumor , Cell Movement , Chemotaxis , Chloramphenicol O-Acetyltransferase/metabolism , Cytoplasm/metabolism , Fluorescent Antibody Technique, Indirect , HL-60 Cells , Humans , Immunoprecipitation , MARVEL Domain-Containing Proteins , Membrane Proteins/metabolism , Microscopy, Confocal , Microscopy, Fluorescence , Molecular Sequence Data , Open Reading Frames , Plasmids/metabolism , Protein Binding , Protein Structure, Tertiary , Proteolipids , RNA/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Saccharomyces cerevisiae/metabolism , Sarcoma/metabolism , Signal Transduction , Transfection , Two-Hybrid System Techniques , U937 Cells
17.
Mol Cells ; 17(2): 316-21, 2004 Apr 30.
Article in English | MEDLINE | ID: mdl-15179048

ABSTRACT

Leukotactin-1 (Lkn-1)/CCL15, is a recently cloned chemotactic chemokine that appears to play important roles in the inflammatory process by recruiting immune cells to inflammatory sites. Expression of the Lkn-1/CCL15 gene is inducible in monocytes but its transcriptional regulation has not been studied. To identify Lkn-1/CCL15 regulatory sequences in monocytic cells, U937 cells were transiently transfected with the luciferase reporter gene linked to various deletions of the Lkn-1/CCL15 promoter region. The region -269 to -43 bp from the transcription start site proved to be important for induction by PMA. This region contained two potential NF-kappaB sites: one between -191 and -182 bp, and the other between -60 and -51 bp. Mutation of either element reduced PMA-induced expression and electrophoretic mobility shift assays revealed that NF-kappaB recognized both potential NF-kappaB sites. In addition, PMA-induction of Lkn-1/CCL15 in transiently transfected U937 cells was blocked by proteasome inhibitor 1. These observations demonstrate that the two NF-kappaB binding sites are essential for PMA-induced Lkn-1/CCL15 expression in human monocytes.


Subject(s)
Chemokines, CC/genetics , Gene Expression Regulation/drug effects , Monocytes/drug effects , NF-kappa B/metabolism , Regulatory Sequences, Nucleic Acid , Tetradecanoylphorbol Acetate/pharmacology , Binding Sites , Cell Line , Chemokines, CC/metabolism , Enzyme Inhibitors/metabolism , Humans , Monocytes/cytology , Monocytes/physiology
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