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Obakan P, Arisan ED, Calcabrini A, Agostinelli E, Bolkent S, Palavan-Unsal N. Activation of polyamine catabolic enzymes involved in diverse responses against epibrassinolide-induced apoptosis in LNCaP and DU145 prostate cancer cell lines. Amino Acids 2014; 46:553-64. [PMID: 23963538 DOI: 10.1007/s00726-013-1574-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/31/2013] [Indexed: 12/11/2022]
Abstract
Epibrassinolide (EBR) is a biologically active compound of the brassinosteroids, steroid-derived plant growth regulator family. Generally, brassinosteroids are known for their cell expansion and cell division-promoting roles. Recently, EBR was shown as a potential apoptotic inducer in various cancer cells without affecting the non-tumor cell growth. Androgen signaling controls cell proliferation through the interaction with the androgen receptor (AR) in the prostate gland. Initially, the development of prostate cancer is driven by androgens. However, in later stages, a progress to the androgen-independent stage is observed, resulting in metastatic prostate cancer. The androgen-responsive or -irresponsive cells are responsible for tumor heterogeneity, which is an obstacle to effective anti-cancer therapy. Polyamines are amine-derived organic compounds, known for their role in abnormal cell proliferation as well as during malignant transformation. Polyamine catabolism-targeting agents are being investigated against human cancers. Many chemotherapeutic agents including polyamine analogs have been demonstrated to induce polyamine catabolism that depletes polyamine levels and causes apoptosis in tumor models. In our study, we aimed to investigate the mechanism of apoptotic cell death induced by EBR, related with polyamine biosynthetic and catabolic pathways in LNCaP (AR+), DU145 (AR-) prostate cancer cell lines and PNT1a normal prostate epithelial cell line. Induction of apoptotic cell death was observed in prostate cancer cell lines after EBR treatment. In addition, EBR induced the decrease of intracellular polyamine levels, accompanied by a significant ornithine decarboxylase (ODC) down-regulation in each prostate cancer cell and also modulated ODC antizyme and antizyme inhibitor expression levels only in LNCaP cells. Catabolic enzymes SSAT and PAO expression levels were up-regulated in both cell lines; however, the specific SSAT and PAO siRNA treatments prevented the EBR-induced apoptosis only in LNCaP (AR+) cells. In a similar way, MDL 72,527, the specific PAO and SMO inhibitor, co-treatment with EBR during 24 h, reduced the formation of cleaved fragments of PARP in LNCaP (AR+) cells.
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Affiliation(s)
- Pinar Obakan
- Department of Molecular Biology and Genetics, Istanbul Kultur University, Atakoy Campus, Bakirkoy, 34156, Istanbul, Turkey
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Arumugam A, Weng Z, Talwelkar SS, Chaudhary SC, Kopelovich L, Elmets CA, Afaq F, Athar M. Inhibiting cycloxygenase and ornithine decarboxylase by diclofenac and alpha-difluoromethylornithine blocks cutaneous SCCs by targeting Akt-ERK axis. PLoS One 2013; 8:e80076. [PMID: 24260338 PMCID: PMC3832653 DOI: 10.1371/journal.pone.0080076] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/08/2013] [Indexed: 01/04/2023] Open
Abstract
Non-melanoma skin cancer (NMSC) is the most common type of skin cancer in Caucasian populations. Its increasing incidence has been a major public health concern. Elevated expressions of ODC and COX-2 are associated with both murine and human NMSCs. Inhibition of these molecular targets singly employing their respective small molecule inhibitors showed limited success. Here, we show that combined blockade of ODC and COX-2 using their potent inhibitors, DFMO and diclofenac respectively abrogates growth of A431 epidermal xenograft tumors in nu/nu mice by more than 90%. The tumor growth inhibition was associated with a diminution in the proliferation and enhancement in apoptosis. The proliferation markers such as PCNA and cyclin D1 were reduced. TUNEL-positive apoptotic cells and cleaved caspase-3 were increased in the residual tumors. These agents also manifested direct target-unrelated effects. Reduced expression of phosphorylated MAPKAP-2, ERK, and Akt (ser(473) & thr(308)) were noticed. The mechanism by which combined inhibition of ODC/COX attenuated tumor growth and invasion involved reduction in EMT. Akt activation by ODC+COX-2 over-expression was the key player in this regard as Akt inhibition manifested effects similar to those observed by the combined inhibition of ODC+COX-2 whereas forced over-expression of Akt resisted against DFMO+diclofenac treatment. These data suggest that ODC+COX-2 over-expression together leads to pathogenesis of aggressive and invasive cutaneous carcinomas by activating Akt signaling pathway, which through augmenting EMT contributes to tumor invasion.
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Affiliation(s)
- Aadithya Arumugam
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Zhiping Weng
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Sarang S. Talwelkar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Sandeep C. Chaudhary
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Levy Kopelovich
- Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Craig A. Elmets
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Farrukh Afaq
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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Zimmermann S, Oufir M, Leroux A, Krauth-Siegel RL, Becker K, Kaiser M, Brun R, Hamburger M, Adams M. Cynaropicrin targets the trypanothione redox system in Trypanosoma brucei. Bioorg Med Chem 2013; 21:7202-9. [PMID: 24080104 DOI: 10.1016/j.bmc.2013.08.052] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 08/16/2013] [Accepted: 08/23/2013] [Indexed: 11/19/2022]
Abstract
In mice cynaropicrin (CYN) potently inhibits the proliferation of Trypanosoma brucei-the causative agent of Human African Trypanosomiasis-by a so far unknown mechanism. We hypothesized that CYNs α,β-unsaturated methylene moieties act as Michael acceptors for glutathione (GSH) and trypanothione (T(SH)2), the main low molecular mass thiols essential for unique redox metabolism of these parasites. The analysis of this putative mechanism and the effects of CYN on enzymes of the T(SH)2 redox metabolism including trypanothione reductase, trypanothione synthetase, glutathione-S-transferase, and ornithine decarboxylase are shown. A two step extraction protocol with subsequent UPLC-MS/MS analysis was established to quantify intra-cellular CYN, T(SH)2, GSH, as well as GS-CYN and T(S-CYN)2 adducts in intact T. b. rhodesiense cells. Within minutes of exposure to CYN, the cellular GSH and T(SH)2 pools were entirely depleted, and the parasites entered an apoptotic stage and died. CYN also showed inhibition of the ornithine decarboxylase similar to the positive control eflornithine. Significant interactions with the other enzymes involved in the T(SH)2 redox metabolism were not observed. Alongside many other biological activities sesquiterpene lactones including CYN have shown antitrypanosomal effects, which have been postulated to be linked to formation of Michael adducts with cellular nucleophiles. Here the interaction of CYN with biological thiols in a cellular system in general, and with trypanosomal T(SH)2 redox metabolism in particular, thus offering a molecular explanation for the antitrypanosomal activity is demonstrated. At the same time, the study provides a novel extraction and analysis protocol for components of the trypanosomal thiol metabolism.
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Affiliation(s)
- Stefanie Zimmermann
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland; Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
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Gu X, Reid D, Higham DJ, Gilbert D. Mathematical modelling of polyamine metabolism in bloodstream-form Trypanosoma brucei: an application to drug target identification. PLoS One 2013; 8:e53734. [PMID: 23372667 PMCID: PMC3553166 DOI: 10.1371/journal.pone.0053734] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 12/04/2012] [Indexed: 11/23/2022] Open
Abstract
We present the first computational kinetic model of polyamine metabolism in bloodstream-form Trypanosoma brucei, the causative agent of human African trypanosomiasis. We systematically extracted the polyamine pathway from the complete metabolic network while still maintaining the predictive capability of the pathway. The kinetic model is constructed on the basis of information gleaned from the experimental biology literature and defined as a set of ordinary differential equations. We applied Michaelis-Menten kinetics featuring regulatory factors to describe enzymatic activities that are well defined. Uncharacterised enzyme kinetics were approximated and justified with available physiological properties of the system. Optimisation-based dynamic simulations were performed to train the model with experimental data and inconsistent predictions prompted an iterative procedure of model refinement. Good agreement between simulation results and measured data reported in various experimental conditions shows that the model has good applicability in spite of there being gaps in the required data. With this kinetic model, the relative importance of the individual pathway enzymes was assessed. We observed that, at low-to-moderate levels of inhibition, enzymes catalysing reactions of de novo AdoMet (MAT) and ornithine production (OrnPt) have more efficient inhibitory effect on total trypanothione content in comparison to other enzymes in the pathway. In our model, prozyme and TSHSyn (the production catalyst of total trypanothione) were also found to exhibit potent control on total trypanothione content but only when they were strongly inhibited. Different chemotherapeutic strategies against T. brucei were investigated using this model and interruption of polyamine synthesis via joint inhibition of MAT or OrnPt together with other polyamine enzymes was identified as an optimal therapeutic strategy.
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Affiliation(s)
- Xu Gu
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom.
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Zhu Q, Jin L, Casero RA, Davidson NE, Huang Y. Role of ornithine decarboxylase in regulation of estrogen receptor alpha expression and growth in human breast cancer cells. Breast Cancer Res Treat 2012; 136:57-66. [PMID: 22976807 PMCID: PMC3715085 DOI: 10.1007/s10549-012-2235-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 08/25/2012] [Indexed: 12/30/2022]
Abstract
Our previous studies demonstrated that specific polyamine analogues, oligoamines, down-regulated the activity of a key polyamine biosynthesis enzyme, ornithine decarboxylase (ODC), and suppressed expression of estrogen receptor alpha (ERα) in human breast cancer cells. However, the mechanism underlying the potential regulation of ERα expression by polyamine metabolism has not been explored. Here, we demonstrated that RNAi-mediated knockdown of ODC (ODC KD) down-regulated the polyamine pool, and hindered growth in ERα-positive MCF7 and T47D and ERα-negative MDA-MB-231 breast cancer cells. ODC KD significantly induced the expression and activity of the key polyamine catabolism enzymes, spermine oxidase (SMO) and spermidine/spermine N (1)-acetyltransferase (SSAT). However, ODC KD-induced growth inhibition could not be reversed by exogenous spermidine or overexpression of antizyme inhibitor (AZI), suggesting that regulation of ODC on cell proliferation may involve the signaling pathways independent of polyamine metabolism. In MCF7 and T47D cells, ODC KD, but not DFMO treatment, diminished the mRNA and protein expression of ERα. Overexpression of antizyme (AZ), an ODC inhibitory protein, suppressed ERα expression, suggesting that ODC plays an important role in regulation of ERα expression. Decrease of ERα expression by ODC siRNA altered the mRNA expression of a subset of ERα response genes. Our previous analysis showed that oligoamines disrupt the binding of Sp1 family members to an ERα minimal promoter element containing GC/CA-rich boxes. By using DNA affinity precipitation and mass spectrometry analysis, we identified ZBTB7A, MeCP2, PARP-1, AP2, and MAZ as co-factors of Sp1 family members that are associated with the ERα minimal promoter element. Taken together, these data provide insight into a novel antiestrogenic mechanism for polyamine biosynthesis enzymes in breast cancer.
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Affiliation(s)
- Qingsong Zhu
- The Sidney Kimmel Comprehensive Cancer Center, Johns, Hopkins University, Baltimore, MD, USA
| | - Lihua Jin
- The Sidney Kimmel Comprehensive Cancer Center, Johns, Hopkins University, Baltimore, MD, USA
| | - Robert A. Casero
- The Sidney Kimmel Comprehensive Cancer Center, Johns, Hopkins University, Baltimore, MD, USA
| | - Nancy E. Davidson
- Department of Pharmacology & Chemical Biology, University, of Pittsburgh, Pittsburgh, PA, USA
- University of Pittsburgh Cancer Institute, 5150 Centre Avenue, Suite 500, Pittsburgh, PA 15213, USA,
| | - Yi Huang
- Department of Pharmacology & Chemical Biology, University, of Pittsburgh, Pittsburgh, PA, USA
- University of Pittsburgh Cancer Institute, 5150 Centre Avenue, Suite 500, Pittsburgh, PA 15213, USA,
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Rao JN, Rathor N, Zhuang R, Zou T, Liu L, Xiao L, Turner DJ, Wang JY. Polyamines regulate intestinal epithelial restitution through TRPC1-mediated Ca²+ signaling by differentially modulating STIM1 and STIM2. Am J Physiol Cell Physiol 2012; 303:C308-17. [PMID: 22592407 PMCID: PMC3423028 DOI: 10.1152/ajpcell.00120.2012] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/14/2012] [Indexed: 11/22/2022]
Abstract
Early epithelial restitution occurs as a consequence of intestinal epithelial cell (IEC) migration after wounding, and its defective regulation is implicated in various critical pathological conditions. Polyamines stimulate intestinal epithelial restitution, but their exact mechanism remains unclear. Canonical transient receptor potential-1 (TRPC1)-mediated Ca(2+) signaling is crucial for stimulation of IEC migration after wounding, and induced translocation of stromal interaction molecule 1 (STIM1) to the plasma membrane activates TRPC1-mediated Ca(2+) influx and thus enhanced restitution. Here, we show that polyamines regulate intestinal epithelial restitution through TRPC1-mediated Ca(2+) signaling by altering the ratio of STIM1 to STIM2. Increasing cellular polyamines by ectopic overexpression of the ornithine decarboxylase (ODC) gene stimulated STIM1 but inhibited STIM2 expression, whereas depletion of cellular polyamines by inhibiting ODC activity decreased STIM1 but increased STIM2 levels. Induced STIM1/TRPC1 association by increasing polyamines enhanced Ca(2+) influx and stimulated epithelial restitution, while decreased formation of the STIM1/TRPC1 complex by polyamine depletion decreased Ca(2+) influx and repressed cell migration. Induced STIM1/STIM2 heteromers by polyamine depletion or STIM2 overexpression suppressed STIM1 membrane translocation and inhibited Ca(2+) influx and epithelial restitution. These results indicate that polyamines differentially modulate cellular STIM1 and STIM2 levels in IECs, in turn controlling TRPC1-mediated Ca(2+) signaling and influencing cell migration after wounding.
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Affiliation(s)
- Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Hsieh JY, Yang JY, Lin CL, Liu GY, Hung HC. Minimal antizyme peptide fully functioning in the binding and inhibition of ornithine decarboxylase and antizyme inhibitor. PLoS One 2011; 6:e24366. [PMID: 21931692 PMCID: PMC3170320 DOI: 10.1371/journal.pone.0024366] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 08/08/2011] [Indexed: 01/10/2023] Open
Abstract
Antizyme (AZ) is a protein with 228 amino acid residues that regulates ornithine decarboxylase (ODC) by binding to ODC and dissociating its homodimer, thus inhibiting its enzyme activity. Antizyme inhibitor (AZI) is homologous to ODC, but has a higher affinity than ODC for AZ. In this study, we quantified the biomolecular interactions between AZ and ODC as well as AZ and AZI to identify functional AZ peptides that could bind to ODC and AZI and inhibit their function as efficiently as the full-length AZ protein. For these AZ peptides, the inhibitory ability of AZ_95-228 was similar to that of AZ_WT. Furthermore, AZ_95-176 displayed an inhibition (IC50: 0.20 µM) similar to that of AZ-95-228 (IC50: 0.16 µM), even though a large segment spanning residues 177–228 was deleted. However, further deletion of AZ_95-176 from either the N-terminus or the C-terminus decreased its ability to inhibit ODC. The AZ_100-176 and AZ_95-169 peptides displayed a noteworthy decrease in ability to inhibit ODC, with IC50 values of 0.43 and 0.37 µM, respectively. The AZ_95-228, AZ_100-228 and AZ_95-176 peptides had IC50 values comparable to that of AZ_WT and formed AZ-ODC complexes with Kd,AZ-ODC values of 1.5, 5.3 and 5.6 µM, respectively. Importantly, our data also indicate that AZI can rescue AZ peptide-inhibited ODC enzyme activity and that it can bind to AZ peptides with a higher affinity than ODC. Together, these data suggest that these truncated AZ proteins retain their AZI-binding ability. Thus, we suggest that AZ_95-176 is the minimal AZ peptide that is fully functioning in the binding of ODC and AZI and inhibition of their function.
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Affiliation(s)
- Ju-Yi Hsieh
- Department of Life Sciences and Institute of Bioinformatics, National Chung Hsing University, Taichung, Taiwan
| | - Jung-Yen Yang
- National Nano Device Laboratories and Department of Electrical Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Chih-Li Lin
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Guang-Yaw Liu
- Institute of Microbiology & Immunology, Chung Shan Medical University, and Division of Allergy, Immunology, and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan
- * E-mail: (H-CH); (G-YL)
| | - Hui-Chih Hung
- Department of Life Sciences and Institute of Bioinformatics, National Chung Hsing University, Taichung, Taiwan
- Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- * E-mail: (H-CH); (G-YL)
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Liu YC, Liu YL, Su JY, Liu GY, Hung HC. Critical factors governing the difference in antizyme-binding affinities between human ornithine decarboxylase and antizyme inhibitor. PLoS One 2011; 6:e19253. [PMID: 21552531 PMCID: PMC3084279 DOI: 10.1371/journal.pone.0019253] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 03/24/2011] [Indexed: 12/18/2022] Open
Abstract
Both ornithine decarboxylase (ODC) and its regulatory protein, antizyme inhibitor (AZI), can bind with antizyme (AZ), but the latter has a higher AZ-binding affinity. The results of this study clearly identify the critical amino acid residues governing the difference in AZ-binding affinities between human ODC and AZI. Inhibition experiments using a series of ODC mutants suggested that residues 125 and 140 may be the key residues responsible for the differential AZ-binding affinities. The ODC_N125K/M140K double mutant demonstrated a significant inhibition by AZ, and the IC50 value of this mutant was 0.08 µM, three-fold smaller than that of ODC_WT. Furthermore, the activity of the AZ-inhibited ODC_N125K/M140K enzyme was hardly rescued by AZI. The dissociation constant (Kd) of the [ODC_N125K/M140K]-AZ heterodimer was approximately 0.02 µM, which is smaller than that of WT_ODC by approximately 10-fold and is very close to the Kd value of AZI_WT, suggesting that ODC_N125K/M140K has an AZ-binding affinity higher than that of ODC_WT and similar to that of AZI. The efficiency of the AZI_K125N/K140M double mutant in the rescue of AZ-inhibited ODC enzyme activity was less than that of AZI_WT. The Kd value of [AZI_K125N/K140M]-AZ was 0.18 µM, nine-fold larger than that of AZI_WT and close to the Kd value of ODC_WT, suggesting that AZI_K125N/K140M has an AZ-binding affinity lower than that of AZI_WT and similar to that of ODC. These data support the hypothesis that the differences in residues 125 and 140 in ODC and AZI are responsible for the differential AZ-binding affinities.
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Affiliation(s)
- Yen-Chin Liu
- Department of Life Sciences and Institute of Genomics and Bioinformatics, National Chung-Hsing University, Taichung, Taiwan
| | - Yi-Liang Liu
- Department of Life Sciences and Institute of Genomics and Bioinformatics, National Chung-Hsing University, Taichung, Taiwan
- Division of Allergy, Immunology and Rheumatology and Institute of Immunology, Chung-Shan Medical University and Hospital, Taichung, Taiwan
| | - Jia-Yang Su
- Department of Life Sciences and Institute of Genomics and Bioinformatics, National Chung-Hsing University, Taichung, Taiwan
| | - Guang-Yaw Liu
- Division of Allergy, Immunology and Rheumatology and Institute of Immunology, Chung-Shan Medical University and Hospital, Taichung, Taiwan
- * E-mail: (HCH); (GYL)
| | - Hui-Chih Hung
- Department of Life Sciences and Institute of Genomics and Bioinformatics, National Chung-Hsing University, Taichung, Taiwan
- * E-mail: (HCH); (GYL)
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Athar M, Walsh SB, Kopelovich L, Elmets CA. Pathogenesis of nonmelanoma skin cancers in organ transplant recipients. Arch Biochem Biophys 2011; 508:159-63. [PMID: 21232524 DOI: 10.1016/j.abb.2011.01.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 01/05/2011] [Accepted: 01/06/2011] [Indexed: 02/08/2023]
Abstract
Nonmelanoma skin cancer (NMSC) is the most common human cancer, with an incidence of more than 1.2 million per year in the USA. The risk for the development of NMSCs increases by approximately 10-250 fold in chronically immune suppressed organ transplant recipients (OTRs). Solar UVB is the most common etiologic factor in the development of this neoplasm, both in immune competent and immune suppressed populations. This review provides a description of NMSC in OTRs. It also provides an account of the various immunologic and non-immune-dependent mechanisms involved in the pathogenesis and progression of NMSCs in OTRs. Finally, this review addresses possible strategies for the prevention of this cancer, particularly focusing on the aspects that may be incorporated to prevent negative effects of chemopreventive chemicals on graft survival.
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Affiliation(s)
- Mohammad Athar
- Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
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Smithson DC, Lee J, Shelat AA, Phillips MA, Guy RK. Discovery of potent and selective inhibitors of Trypanosoma brucei ornithine decarboxylase. J Biol Chem 2010; 285:16771-81. [PMID: 20220141 PMCID: PMC2878083 DOI: 10.1074/jbc.m109.081588] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 02/03/2010] [Indexed: 11/06/2022] Open
Abstract
Human African trypanosomiasis, caused by the eukaryotic parasite Trypanosoma brucei, is a serious health problem in much of central Africa. The only validated molecular target for treatment of human African trypanosomiasis is ornithine decarboxylase (ODC), which catalyzes the first step in polyamine metabolism. Here, we describe the use of an enzymatic high throughput screen of 316,114 unique molecules to identify potent and selective inhibitors of ODC. This screen identified four novel families of ODC inhibitors, including the first inhibitors selective for the parasitic enzyme. These compounds display unique binding modes, suggesting the presence of allosteric regulatory sites on the enzyme. Docking of a subset of these inhibitors, coupled with mutagenesis, also supports the existence of these allosteric sites.
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Affiliation(s)
- David C. Smithson
- From the Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
- the Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, California 94143-2280, and
| | - Jeongmi Lee
- the Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041
| | - Anang A. Shelat
- From the Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Margaret A. Phillips
- the Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041
| | - R. Kiplin Guy
- From the Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
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Bailey HH, Kim K, Verma AK, Sielaff K, Larson PO, Snow S, Lenaghan T, Viner JL, Douglas J, Dreckschmidt NE, Hamielec M, Pomplun M, Sharata HH, Puchalsky D, Berg ER, Havighurst TC, Carbone PP. A randomized, double-blind, placebo-controlled phase 3 skin cancer prevention study of {alpha}-difluoromethylornithine in subjects with previous history of skin cancer. Cancer Prev Res (Phila) 2010; 3:35-47. [PMID: 20051371 DOI: 10.1158/1940-6207.capr-09-0096] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Preclinical studies have shown that the inhibition of ornithine decarboxylase (ODC) by alpha-difluoromethylornithine (DFMO) and resultant decreases in tissue concentrations of polyamines (putrescine and spermidine) prevents neoplastic developments in many tissue types. Clinical studies of oral DFMO at 500 mg/m(2)/day revealed it to be safe and tolerable and resulted in significant inhibition of phorbol ester-induced skin ODC activity. Two hundred and ninety-one participants (mean age, 61 years; 60% male) with a history of prior nonmelanoma skin cancer (NMSC; mean, 4.5 skin cancers) were randomized to oral DFMO (500 mg/m(2)/day) or placebo for 4 to 5 years. There was a trend toward a history of more prior skin cancers in subjects randomized to placebo, but all other characteristics including sunscreen and nonsteroidal anti-inflammatory drug use were evenly distributed. Evaluation of 1,200 person-years of follow-up revealed a new NMSC rate of 0.5 events/person/year. The primary end point, new NMSCs, was not significantly different between subjects taking DFMO and placebo (260 versus 363 cancers, P = 0.069, two-sample t test). Evaluation of basal cell (BCC) and squamous cell cancers separately revealed very little difference in squamous cell cancer between treatment groups but a significant difference in new BCC (DFMO, 163 cancers; placebo, 243 cancers; expressed as event rate of 0.28 BCC/person/year versus 0.40 BCC/person/year, P = 0.03). Compliance with DFMO was >90% and it seemed to be well tolerated with evidence of mild ototoxicity as measured by serial audiometric examination when compared with placebo subjects. The analysis of normal skin biopsies revealed a significant (P < 0.05) decrease in 12-0-tetradecanoylphorbol-13-acetate-induced ODC activity (month 24, 36, and 48) and putrescine concentration (month 24 and 36 only) in DFMO subjects. Subjects with a history of skin cancer taking daily DFMO had an insignificant reduction (P = 0.069) in new NMSC that was predominantly due to a marked reduction in new BCC. Based on these data, the potential of DFMO, alone or in combination, to prevent skin cancers should be explored further.
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Affiliation(s)
- Howard H Bailey
- University of Wisconsin Paul P. Carbone Cancer Center, Madison, USA.
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13
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Prasad L, Khan TH, Sehrawat A, Sultana S. Modulatory effect of Morus indica against two-stage skin carcinogenesis in Swiss albino mice: possible mechanism by inhibiting aryl hydrocarbon hydroxylase. J Pharm Pharmacol 2010; 56:1291-8. [PMID: 15482644 DOI: 10.1211/0022357044373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
The modulatory effect of the methanolic extract of Morus indica on 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced oxidative stress and 7,12-dimethylbenz(a)anthracene induced and croton oil (0.5% per mouse/0.2 mL acetone, v/v) promoted skin tumourigenesis in Swiss albino mice was studied. The efficacy of the M. indica extract was also evaluated in-vitro by studying the inhibition of the activity and level of aryl hydrocarbon hydroxylase, cytochrome P450, DNA sugar damage in calf thymus DNA and Fe++/ascorbate-induced lipid peroxidation in microsomes of mice. Significant increases in the activity of antioxidant enzymes (P < 0.001) and a concomitant decrease (P < 0.001) in the cutaneous malondialdehyde level were observed at three doses of plant extract (2.5, 5.0 and 7.5 mg kg−1). Application of M. indica 1 h before each application of croton oil showed inhibitory effects on tumour promotion in terms of a reduction in the number of tumours/mouse and percentage of mice with tumours. It was also accompanied by an extension of the tumour latency period. TPA, which resulted in a rapid and transient stimulation of mouse epidermal ornithine decarboxylase activity (P < 0.001), was inhibited dose dependently by pre-treatment with M. indica extract (P < 0.001). The results suggest that M. indica extract may be useful as a therapeutic agent for cancer control as it blocks or suppresses events associated with chemical carcinogenesis.
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Affiliation(s)
- Lakshmi Prasad
- Section of Chemoprevention and Nutrition Toxicology, Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), Hamdard Nagar, New Delhi 110062, India
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14
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Rehman R, Khan R, Soomro MS, Aslam M. Effect of difluoromethylornithine on thyroid function in rats. J Ayub Med Coll Abbottabad 2009; 21:87-89. [PMID: 20524478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND A variety of stimuli cause a rapid increase in polyamine synthesis by increasing an enzyme ornithine decarboxylase required for the biosynthetic pathway of protein synthesis. Difluoromethyl ornithine is a selective inhibitor of this enzyme and hence arrests cell replication strikingly. Its effects on thyroid gland are studied with respect to change in animal's weight and levels of Triiodothyronine, Thyroxine and Thyroid stimulating hormone. The study was conducted to evaluate the inhibitory effects of Di-fluoromethyl ornithine (DFMO) administration on polyamine metabolism of thyroid gland in rats. METHODS The study was conducted on rats weighing 248 to 320 grams, divided into control and DFMO treated group. A dose of 50 mg/rat was administered subcutaneously to the treated group for 5 consecutive days and placebo (normal saline) injections to control group. On sixth day, blood was collected by cardiac puncture and serum was separated. Serum T3, T4 and TSH were analyzed with the help of radioimmunoassay in both groups. RESULTS In treated group there was a fall in T3, T4 concentration with significant rise in TSH concentration as compared to control group. CONCLUSION DFMO (Difluoro methyl ornithine) decreases cellular proliferation of thyroid gland as is assessed by decrease in thyroid hormone levels. The hypothalamo pituitary thyroid axis however remains intact as is shown by a feedback rise in TSH concentration. DFMO can thus be employed for anti-neoplastic clinical trials on account of interference with activity of ODC (Ornithine Decarboxylase) fundamental for polyamine biosynthesis.
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Affiliation(s)
- Rehana Rehman
- Department of Physiology, Bahria Medical University, Karachi, Pakistan.
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15
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Müller IB, Wu F, Bergmann B, Knöckel J, Walter RD, Gehring H, Wrenger C. Poisoning pyridoxal 5-phosphate-dependent enzymes: a new strategy to target the malaria parasite Plasmodium falciparum. PLoS One 2009; 4:e4406. [PMID: 19197387 PMCID: PMC2634962 DOI: 10.1371/journal.pone.0004406] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Accepted: 12/12/2008] [Indexed: 11/18/2022] Open
Abstract
The human malaria parasite Plasmodium falciparum is able to synthesize de novo pyridoxal 5-phosphate (PLP), a crucial cofactor, during erythrocytic schizogony. However, the parasite possesses additionally a pyridoxine/pyridoxal kinase (PdxK) to activate B6 vitamers salvaged from the host. We describe a strategy whereby synthetic pyridoxyl-amino acid adducts are channelled into the parasite. Trapped upon phosphorylation by the plasmodial PdxK, these compounds block PLP-dependent enzymes and thus impair the growth of P. falciparum. The novel compound PT3, a cyclic pyridoxyl-tryptophan methyl ester, inhibited the proliferation of Plasmodium very efficiently (IC(50)-value of 14 microM) without harming human cells. The non-cyclic pyridoxyl-tryptophan methyl ester PT5 and the pyridoxyl-histidine methyl ester PHME were at least one order of magnitude less effective or completely ineffective in the case of the latter. Modeling in silico indicates that the phosphorylated forms of PT3 and PT5 fit well into the PLP-binding site of plasmodial ornithine decarboxylase (PfODC), the key enzyme of polyamine synthesis, consistent with the ability to abolish ODC activity in vitro. Furthermore, the antiplasmodial effect of PT3 is directly linked to the capability of Plasmodium to trap this pyridoxyl analog, as shown by an increased sensitivity of parasites overexpressing PfPdxK in their cytosol, as visualized by GFP fluorescence.
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Affiliation(s)
- Ingrid B Müller
- Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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16
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Oyagbemi AA, Saba AB, Ibraheem AO. Curcumin: from food spice to cancer prevention. Asian Pac J Cancer Prev 2009; 10:963-967. [PMID: 20192567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Curcumin [1, 7-bis (4-hydroxy-3-methoxyphenyl)-1, 6 heptadiene-3, 5-dione] is an orange-yellow component of turmeric (Curcuma longa), a spice often found in curry powder. It is known to have a variety of biologic and pharmacologic activities, including anti-inflammatory, anti-oxidant, and anticarcinogenic potential. It is a potent inhibitor of cytochrome P450 with capacity to simultaneously induce detoxifying enzymes such as glutathione S-transferase and as such may find application as a chemopreventive agent. Curcumin is a potent inhibitor of cyclooxygenase-2, lipooxygenase, ornithine decarboxylase (ODC), nuclear factor-kappaB, c-Jun N-terminal kinase and protein kinase C and has also been demonstrated to play a vital role against pathological conditions such as cancer, atherosclerosis, and neurodegenerative diseases.
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Affiliation(s)
- Ademola A Oyagbemi
- Department of Veterinary Physiology, Biochemistry and Pharmacology, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria.
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17
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Rahman S, Sultana S. Glycyrrhizin exhibits potential chemopreventive activity on 12-O-tetradecanoyl phorbol-13-acetate-induced cutaneous oxidative stress and tumor promotion in swiss albino mice. J Enzyme Inhib Med Chem 2008; 22:363-9. [PMID: 17674818 DOI: 10.1080/14756360601074094] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Glycyrrhizin and its aglycone, glycyrrhetic acid has been found useful for various therapeutic purposes. Glycyrrhizin has been shown to possess many physiological functions like anti-inflammatory activity, detoxification and inhibition of carcinogenic promoters. 12-O-Tetradecanoyl phorbol-13-acetate (TPA), a well-known phorbal ester is known for its tumor promotion activity. The induction of inflammation in skin mediated by TPA is believed to be governed by cyclooxygenase (COX), lipoxygenase and ornithine decarboxylase (ODC). These markers of inflammatory responses are important for skin tumor promotion. In our present study, we studied the chemopreventive effect of glycyrrhizin on TPA (20 nmol/0.2 mL acetone/animal, topically)-induced oxidative stress and hyperproliferation markers in skin. TPA enhanced lipid peroxidation with reduction in the level of catalase, glutathione, glutathione peroxidase, glutathione reductase and glutathione-s-transferase. TPA treatment also enhanced ODC activity and [3H] thymidine incorporation into cutaneous DNA. Prophylactic treatment of mice with glycyrrhizin (2.0 & 4.0 mg/0.2 mL acetone/animal, topically) resulted in a significant decrease in cutaneous microsomal lipid peroxidation (P < 0.001) and recovery of cutaneous glutathione content (P < 0.001) and its dependent enzymes. A significant inhibition in ODC activity and DNA synthesis (P < 0.001) was also observed. Thus, the results demonstrate that pretreatment with glycyrrhizin is protective against TPA-induced oxidative stress and tumor promotion in Swiss albino mice.
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Affiliation(s)
- Sahar Rahman
- Section of Chemoprevention and Nutrition Toxicology, Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), Hamdard Nagar, New Delhi 110062, India
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18
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Sarfaraz S, Siddiqui IA, Syed DN, Afaq F, Mukhtar H. Guggulsterone modulates MAPK and NF-kappaB pathways and inhibits skin tumorigenesis in SENCAR mice. Carcinogenesis 2008; 29:2011-8. [PMID: 18684729 PMCID: PMC2722858 DOI: 10.1093/carcin/bgn180] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 07/29/2008] [Accepted: 07/30/2008] [Indexed: 11/13/2022] Open
Abstract
Guggulsterone (GUG), a resin of the Commiphora mukul tree, has been used in ayurvedic medicine for centuries to treat a variety of ailments. Recent studies have suggested that GUG may also possess anticancer effects. In the present study, we show that GUG possesses antitumor-promoting effects in SENCAR mouse skin tumorigenesis model. We first determined the effect of topical application of GUG to mice against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced conventional markers and other novel markers of skin tumor promotion. We found that topical application of GUG (1.6 micromol per mouse) 30 min prior to TPA (3.2 nmol per mouse) application onto the skin of mice afforded significant inhibition against TPA-mediated increase in skin edema and hyperplasia. Topical application of GUG was also found to result in substantial inhibition against TPA-induced epidermal (i) ornithine decarboxylase (ODC) activity; (ii) ODC, cyclooxygenase-2 and inducible nitric oxide synthase protein expressions; (iii) phosphorylation of extracellular signal-regulated kinase 1/2, c-jun N-terminal kinases and p38; (iv) activation of NF-kappaB/p65 and IKK alpha/beta and (v) phosphorylation and degradation of I kappaB alpha. We next assessed the effect of topically applied GUG on TPA-induced skin tumor promotion in 7,12-dimethyl benz[a]anthracene-initiated mice. Compared with non-GUG-pretreated mice, animals pretreated with GUG showed significantly reduced tumor incidence, lower tumor body burden and a significant delay in the latency period for tumor appearance from 5 to 11 weeks. These results provide the first evidence that GUG possesses anti-skin tumor-promoting effects in SENCAR mice and inhibits conventional as well as novel biomarkers of tumor promotion. In summary, GUG could be useful for delaying tumor growth in humans.
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Affiliation(s)
- Sami Sarfaraz
- Present address: Medical Oncology Branch, National Cancer Institute, Building 37, Room 1136, 37 Convent Drive, Bethesda, MD 20892, USA
| | | | | | | | - Hasan Mukhtar
- To whom correspondence should be addressed. Tel: +1 608 263 3927; Fax: +1 608 263 5223;
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19
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Ma JM, Suo SY, Ning QJ. [Structure, functions and metabolisms of antizyme inhibitor]. Sheng Li Ke Xue Jin Zhan 2008; 39:255-257. [PMID: 18819497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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20
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Dawson MI, Hobbs PD, Chan R, Derdzinski K, Helmes CT, Chao W, Meierhenry E, Schiff LJ. Conformational restrictions of the retinoid skeleton. Ciba Found Symp 2008; 113:6-28. [PMID: 2411481 DOI: 10.1002/9780470720943.ch2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of conformationally restricted retinoids has been synthesized and assayed for biological activity. These compounds have aromatic rings in place of selected double bonds of the tetraene side-chain of retinoic acid and could be considered as analogues of retinoic acid in which some of the double bonds possess s-cis topology. Thus far, analogues in which the bonds corresponding to the (5,7E)-, (7,9E)-, (9,11,13E)- and (11,13E)-double bond systems of retinoic acid are restricted to a cisoid conformation have been studied. Analogues were screened for their ability to reverse keratinization in hamster tracheal organ culture and to inhibit the induction of ornithine decarboxylase in mouse epidermis. Selected compounds were also screened in the antipapilloma assay in mice. The toxicity of some analogues on intraperitoneal injection in mice was determined.
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21
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Clark K, Dhoogra M, Louw AI, Birkholtz LM. Transcriptional responses of Plasmodium falciparum to alpha-difluoromethylornithine-induced polyamine depletion. Biol Chem 2008; 389:111-25. [PMID: 18163886 DOI: 10.1515/bc.2008.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract Polyamines are essential polycationic molecules involved in multiple cellular events, including cell differentiation, division and death. Inhibition of polyamine biosynthesis has been considered in diverse therapeutic strategies ranging from tumour suppressors to anti-parasitic agents. In the human malaria parasite, Plasmodium falciparum, inhibition of ornithine decarboxylase (ODC) results in the arrest of schizogony due to polyamine depletion. However, the exact physiological role of the polyamines in the parasite is unknown. Here, we present results of the depletion of polyamines in the malaria parasite by alpha-difluoromethylornithine inhibition of ODC, as observed with differential transcriptome profiling. Upon depletion of their endogenous polyamines, the up- and downregulated parasite transcripts were selected with suppression subtractive hybridisation and differences were detected using blots or DNA microarrays. A direct linkage between polyamine depletion and the differential expression of two distinct transcripts was observed, indicating the existence of a transcriptional feedback response in the P. falciparum transcriptome upon drug challenge. The data presented provide input into the role of the polyamines in the cellular biology of P. falciparum and contribute towards the validation of polyamine biosynthesis as an antimalarial target.
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Affiliation(s)
- Katherine Clark
- Department of Biochemistry, School of Biological Sciences, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa
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22
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Keren-Paz A, Bercovich Z, Kahana C. Antizyme inhibitor: a defective ornithine decarboxylase or a physiological regulator of polyamine biosynthesis and cellular proliferation. Biochem Soc Trans 2007; 35:311-3. [PMID: 17371267 DOI: 10.1042/bst0350311] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
ODC (ornithine decarboxylase) is a central regulator of cellular polyamine synthesis. ODC is a highly regulated enzyme stimulated by a variety of growth-promoting stimuli. ODC overexpression leads to cellular transformation. Cellular ODC levels are determined at transcriptional and translational levels and by regulation of its degradation. Here we review the mechanism of ODC degradation with particular emphasis on AzI (antizyme inhibitor), an ODC homologous protein that appears as a central regulator of ODC stability, cellular polyamine homoeostasis and cellular proliferation.
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Affiliation(s)
- A Keren-Paz
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
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23
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Carrillo C, González NS, Algranati ID. Trypanosoma cruzi as a model system to study the expression of exogenous genes coding for polyamine biosynthetic enzymes. Induction of DFMO resistance in transgenic parasites. Biochim Biophys Acta Gen Subj 2007; 1770:1605-11. [PMID: 17920200 DOI: 10.1016/j.bbagen.2007.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 08/08/2007] [Accepted: 08/10/2007] [Indexed: 11/17/2022]
Abstract
Trypanosoma cruzi, the etiologic agent of Chagas' disease, is a polyamine auxotroph organism because its genome contains neither ornithine decarboxylase (ODC) nor arginine decarboxylase (ADC) genes, presumably lost during evolution. After transformation with a recombinant plasmid bearing the complete coding region of Crithidia fasciculata ODC gene, the transgenic parasites were able to synthesize putrescine and simultaneously became susceptible to alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ODC. We have studied the emergence of DFMO-resistant T. cruzi after one-step selection of ODC-transformed parasites cultivated in the presence of high levels of the drug (5 mM). Our results have indicated a duplication of the ODC gene copy number in the drug-resistant cell line. The ODC transcripts and the corresponding translation products showed very significant increases (about 7- and 25-fold, respectively) in DFMO-resistant parasites, while the ODC enzymatic activity was 5 times higher than in drug-sensitive T. cruzi. The unequal increases of ODC protein and enzymatic activity in DFMO-resistant protozoa strongly suggest that in addition to gene amplification and enhanced transcription and translation, the assembly of ODC polypeptide chains into dimeric active enzyme molecules might also contribute to regulate the development of DFMO resistance.
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Affiliation(s)
- Carolina Carrillo
- Fundación Instituto Leloir, IIBBA-CONICET, and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1405BWE-Buenos Aires, Argentina
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Chen J, Rao JN, Zou T, Liu L, Marasa BS, Xiao L, Zeng X, Turner DJ, Wang JY. Polyamines are required for expression of Toll-like receptor 2 modulating intestinal epithelial barrier integrity. Am J Physiol Gastrointest Liver Physiol 2007; 293:G568-76. [PMID: 17600044 DOI: 10.1152/ajpgi.00201.2007] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Toll-like receptors (TLRs) allow mammalian intestinal epithelium to detect various microbes and activate innate immunity after infection. TLR2 and TLR4 have been identified in intestinal epithelial cells (IECs) as fundamental components of the innate immune response to bacterial pathogens, but the exact mechanism involved in control of TLR expression remains unclear. Polyamines are implicated in a wide variety of biological functions, and regulation of cellular polyamines is a central convergence point for the multiple signaling pathways driving different epithelial cell functions. The current study determined whether polyamines regulate TLR expression, thereby modulating intestinal epithelial barrier function. Depletion of cellular polyamines by inhibiting ornithine decarboxylase (ODC) with alpha-difluoromethylornithine decreased levels of TLR2 mRNA and protein, whereas increased polyamines by ectopic overexpression of the ODC gene enhanced TLR2 expression. Neither intervention changed basal levels of TLR4. Exposure of normal IECs to low-dose (5 microg/ml) LPS increased ODC enzyme activity and stimulated expression of TLR2 but not TLR4, while polyamine depletion prevented this LPS-induced TLR2 expression. Decreased TLR2 in polyamine-deficient cells was associated with epithelial barrier dysfunction. In contrast, increased TLR2 by the low dose of LPS enhanced epithelial barrier function, which was abolished by inhibition of TLR2 expression with specific, small interfering RNA. These results indicate that polyamines are necessary for TLR2 expression and that polyamine-induced TLR2 activation plays an important role in regulating epithelial barrier function.
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Affiliation(s)
- Jie Chen
- Department of Surgery, Baltimore Veterans Affairs Medical Center, 10 North Greene Street, Baltimore, MD 21201, USA.
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25
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Jackson J, Caro JJ, Caro G, Garfield F, Huber F, Zhou W, Lin CS, Shander D, Schrode K. The effect of eflornithine 13.9% cream on the bother and discomfort due to hirsutism. Int J Dermatol 2007; 46:976-81. [PMID: 17822506 DOI: 10.1111/j.1365-4632.2007.03270.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although unwanted facial hair often leads to anxiety and avoidance of social situations, evaluation of treatment outcomes in clinical trials has relied largely on measures external to the patient such as the extent of hair growth or an expert physician's assessment, neglecting to include patient reported outcomes (PRO). To assess the level of bother caused by a dermatological condition (hirsutism) and changes brought on by treatment, the instrument ESTEEM was developed by expanding the Bother Assessment in Skin Conditions (BASC) scale to six questions to cover the discomfort felt in four social situations and bother due to removing facial hair. Each question elicits responses on a visual analog scale. Women participating in two randomized clinical trials evaluated a new treatment (eflornithine 13.9% cream). Analyses examined the level of bother at each visit, the changes with treatment, the correlations with the Physician's Global Assessment, and the effect size. Hirsutism bothers patients considerably. The mean for overall bother was 89% and the mean discomfort in social situations exceeded 80% in nearly all cases. Treatment led to significant reductions in bother on all six items with effect sizes ranging from 0.46 to 1.62. Eflornithine is an effective treatment for unwanted facial hair in women, as reported by the patients. ESTEEM addresses the specific concerns of women with hirsutism.
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Affiliation(s)
- Joseph Jackson
- Bristol Myers-Squibb Pharmaceutical Research Institute, Princeton, New Jersey, USA
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Abstract
Pyridoxal 5'-phosphate (PLP)-dependent ornithine decarboxylase (ODC) is the key enzyme in polyamine synthesis. ODC is overexpressed in many tumor cells and thus a potential drug target. Here we show the design and synthesis of a coenzyme-substrate analogue as a novel precursor inhibitor of ODC. Structural analysis of the crystal structure of human ODC disclosed an additional hydrophobic pocket surrounding the epsilon-amino group of its substrate ornithine. Molecular modeling methods showed favorable interactions of the BOC-protected pyridoxyl-ornithine conjugate, termed POB, in the active site of human ODC. The synthesized and purified POB completely inhibited the activity of newly induced ODC activity at 100 micromol/L in glioma LN229 and COS7 cells. In correlation with the inhibition of ODC activity, a time-dependent inhibition of cell growth was observed in myeloma, glioma LN18 and LN229, Jurkat, COS7, and SW2 small-cell lung cancer cells if DNA synthesis and cell number were measured, but not in the nontumorigenic human aortic smooth muscle cells. POB strongly inhibited cell proliferation not only of low-grade glioma LN229 cells in a dose-dependent manner (IC(50) approximately 50 micromol/L) but also of high-grade glioblastoma multiforme cells. POB is much more efficient in inhibiting proliferation of several types of tumor cells than alpha-DL-difluoromethylornithine, the best known irreversible inhibitor of ODC.
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Affiliation(s)
- Fang Wu
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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Ray RM, Bhattacharya S, Johnson LR. EGFR plays a pivotal role in the regulation of polyamine-dependent apoptosis in intestinal epithelial cells. Cell Signal 2007; 19:2519-27. [PMID: 17825525 PMCID: PMC2699668 DOI: 10.1016/j.cellsig.2007.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 08/06/2007] [Indexed: 11/16/2022]
Abstract
Intracellular polyamine synthesis is regulated by the enzyme ornithine decarboxylase (ODC), and its inhibition by alpha-difluromethylornithine (DFMO), confers resistance to apoptosis. We have previously shown that DFMO leads to the inhibition of de novo polyamine synthesis, which in turn rapidly activates Src, STAT3 and NF-kappaB via integrin beta3 in intestinal epithelial cells. One mechanism to explain these effects involves the activation of upstream growth factor receptors, such as the epidermal growth factor receptor (EGFR). We therefore hypothesized that EGFR phosphorylation regulates the early response to polyamine depletion. DFMO increased EGFR phosphorylation on tyrosine residues 1173 (pY1173) and 845 (pY845) within 5 min. Phosphorylation declined after 10 min and was prevented by the addition of exogenous putrescine to DFMO containing medium. Phosphorylation of EGFR was concomitant with the activation of ERK1/2. Pretreatment with either DFMO or EGF for 1 h protected cells from TNF-alpha/CHX-induced apoptosis. Exogenous addition of polyamines prevented the protective effect of DFMO. In addition, inhibition of integrin beta3 activity (with RGDS), Src activity (with PP2), or EGFR kinase activity (with AG1478), increased basal apoptosis and prevented protection conferred by either DFMO or EGF. Polyamine depletion failed to protect B82L fibroblasts lacking the EGFR (PRN) and PRN cells expressing either a kinase dead EGFR (K721A) or an EGFR (Y845F) mutant lacking the Src phosphorylation site. Conversely, expression of WT-EGFR (WT) restored the protective effect of polyamine depletion. Fibronectin activated the EGFR, Src, ERKs and protected cells from apoptosis. Taken together, our data indicate an essential role of EGFR kinase activity in MEK/ERK-mediated protection, which synergizes with integrin beta3 leading to Src-mediated protective responses in polyamine depleted cells.
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Affiliation(s)
- Ramesh M Ray
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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Kaneko S, Okuda-Ashitaka E, Ando A, Nishimura K, Igarashi K, Maeda M, Furuta K, Suzuki M, Matsumura M, Ito S. Polyamines upregulate the mRNA expression of cationic amino acid transporter-1 in human retinal pigment epithelial cells. Am J Physiol Cell Physiol 2007; 293:C729-37. [PMID: 17494634 DOI: 10.1152/ajpcell.00018.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously showed that ornithine was mainly transported via cationic amino acid transporter (CAT)-1 in human retinal pigment epithelial (RPE) cell line, human telomerase RT (hTERT)-RPE, and that CAT-1 was involved in ornithine cytotoxicity in ornithine-δ-aminotransferase (OAT)-deficient cell produced by a OAT specific inhibitor, 5-fluoromethylornithine (5-FMO). We showed here that CAT-1 mRNA expression was increased by ornithne in OAT-deficient RPE cells, which was reversed by an inhibitor of ornithine decarboxylase (ODC), α-difluoromethylornithine (DFMO). Polyamines, especially spermine, one of the metabolites of ODC, also enhanced the expression of CAT-1 mRNA. ODC mRNA expression was also increased by ornithine and polyamines, and gene silencing of ODC by siRNA decreased ornithine transport activity and its cytotoxicity. In addition, the mRNA of nuclear protein c-myc was also increased in 5-FMO- and ornithine-treated hTERT-RPE cells, and gene silencing of c-myc prevented the induction of CAT-1 and ODC. Increases in expression of CAT-1, ODC, and c-myc, and the inhibition of these stimulated expression by DFMO were also observed in primary porcine RPE cells. These results suggest that spermine plays an important role in stimulation of mRNA expression of CAT-1, which is a crucial role in ornithine cytotoxicity in OAT-deficient hTERT-RPE cells.
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Affiliation(s)
- Shiho Kaneko
- Department of Ophthalmology, Kansai Medical University, Moriguchi, Osaka, Japan
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29
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Feith DJ, Shantz LM, Shoop PL, Keefer KA, Prakashagowda C, Pegg AE. Mouse skin chemical carcinogenesis is inhibited by antizyme in promotion-sensitive and promotion-resistant genetic backgrounds. Mol Carcinog 2007; 46:453-65. [PMID: 17219416 DOI: 10.1002/mc.20294] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Elevated polyamine content and increased ornithine decarboxylase (ODC) activity have been associated with neoplastic growth in numerous animal models and human tissues. Antizyme (AZ) is a negative regulator of polyamine metabolism that inhibits ODC activity, stimulates ODC degradation, and suppresses polyamine uptake. Preliminary evidence, obtained from transgenic mice with tissue specific overexpression of AZ indicates that tumor development can be suppressed by AZ. To extend these studies, we have examined the effect of keratin 5 (K5)- or K6-driven AZ transgenes on 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) chemical carcinogenesis of the skin, in promotion-resistant C57BL/6 and promotion-sensitive DBA/2 mice. On both genetic backgrounds, K6-AZ mice showed a reduction in tumor multiplicity, with 85% fewer tumors than wild-type controls on the C57BL/6 background and 50% fewer tumors on the DBA/2 background. K5-AZ mice developed 50% fewer tumors than controls on both backgrounds. The percent of mice with tumors and tumor size were also reduced in the K5-AZ and K6-AZ groups. Tumor and TPA-treated skin sections from K6-AZ mice exhibited the strongest AZ expression, with localization mainly in suprabasal keratinocytes. K6-AZ mice also had slightly reduced cell proliferation rates in tumors and TPA-treated skin. The lack of a more pronounced effect on cell proliferation is probably explained by the observation that AZ staining did not colocalize with proliferating cell nuclear antigen (PCNA), a marker for the proliferative compartment. These studies demonstrate a tumor-suppressive effect of AZ in C57BL/6 and DBA/2 mice, and confirm the importance of ODC and polyamines in tumor development.
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Affiliation(s)
- David J Feith
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
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30
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Lee J, Michael AJ, Martynowski D, Goldsmith EJ, Phillips MA. Phylogenetic diversity and the structural basis of substrate specificity in the beta/alpha-barrel fold basic amino acid decarboxylases. J Biol Chem 2007; 282:27115-27125. [PMID: 17626020 DOI: 10.1074/jbc.m704066200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta/alpha-barrel fold type basic amino acid decarboxylases include eukaryotic ornithine decarboxylases (ODC) and bacterial and plant enzymes with activity on L-arginine and meso-diaminopimelate. These enzymes catalyze essential steps in polyamine and lysine biosynthesis. Phylogenetic analysis suggests that diverse bacterial species also contain ODC-like enzymes from this fold type. However, in comparison with the eukaryotic ODCs, amino acid differences were identified in the sequence of the 3(10)-helix that forms a key specificity element in the active site, suggesting they might function on novel substrates. Putative decarboxylases from a phylogenetically diverse range of bacteria were characterized to determine their substrate preference. Enzymes from species within Methanosarcina, Pseudomonas, Bartonella, Nitrosomonas, Thermotoga, and Aquifex showed a strong preference for L-ornithine, whereas the enzyme from Vibrio vulnificus (VvL/ODC) had dual specificity functioning well on both L-ornithine and L-lysine. The x-ray structure of VvL/ODC was solved in the presence of the reaction products putrescine and cadaverine to 1.7 and 2.15A, respectively. The overall structure is similar to eukaryotic ODC; however, reorientation of the 3(10)-helix enlarging the substrate binding pocket allows L-lysine to be accommodated. The structure of the putrescine-bound enzyme suggests that a bridging water molecule between the shorter L-ornithine and key active site residues provides the structural basis for VvL/ODC to also function on this substrate. Our data demonstrate that there is greater structural and functional diversity in bacterial polyamine biosynthetic decarboxylases than previously suspected.
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Affiliation(s)
- Jeongmi Lee
- Departments of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041
| | - Anthony J Michael
- Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom
| | - Dariusz Martynowski
- Departments of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041 and the
| | - Elizabeth J Goldsmith
- Departments of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041 and the
| | - Margaret A Phillips
- Departments of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041.
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31
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Hudec J, Burdová M, Kobida L, Komora L, Macho V, Kogan G, Turianica I, Kochanová R, Lozek O, Habán M, Chlebo P. Antioxidant capacity changes and phenolic profile of Echinacea purpurea, nettle (Urtica dioica L.), and dandelion (Taraxacum officinale) after application of polyamine and phenolic biosynthesis regulators. J Agric Food Chem 2007; 55:5689-96. [PMID: 17579437 DOI: 10.1021/jf070777c] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The changes of the antioxidant (AOA) and antiradical activities (ARA) and the total contents of phenolics, anthocyanins, flavonols, and hydroxybenzoic acid in roots and different aerial sections of Echinacea purpurea, nettle, and dandelion, after treatment with ornithine decarboxylase inhibitor, a polyamine inhibitor (O-phosphoethanolamine, KF), and a phenol biosynthesis stimulator (carboxymethyl chitin glucan, CCHG) were analyzed spectrophotometrically; hydroxycinnamic acids content was analyzed by RP-HPLC with UV detection. Both regulators increased the AOA measured as inhibition of peroxidation (IP) in all herb sections, with the exception of Echinacea stems after treatment with KF. In root tissues IP was dramatically elevated mainly after CCHG application: 8.5-fold in Echinacea, 4.14-fold in nettle, and 2.08-fold in dandelion. ARA decrease of Echinacea leaves treated with regulators was in direct relation only with cichoric acid and caftaric acid contents. Both regulators uphold the formation of cinnamic acid conjugates, the most expressive being that of cichoric acid after treatment with CCHG in Echinacea roots from 2.71 to 20.92 mg g(-1). There was a strong relationship between increase of the total phenolics in all sections of Echinacea, as well as in the studied sections of dandelion, and the anthocyanin content.
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Affiliation(s)
- Jozef Hudec
- Department of Agrochemistry and Plant Nutrition, Slovak Agricultural University, 949 76 Nitra, Slovakia.
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Dufe V, Ingner D, Heby O, Khomutov A, Persson L, Al-Karadaghi S. A structural insight into the inhibition of human and Leishmania donovani ornithine decarboxylases by 1-amino-oxy-3-aminopropane. Biochem J 2007; 405:261-8. [PMID: 17407445 PMCID: PMC1904517 DOI: 10.1042/bj20070188] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The critical role of polyamines in key processes such as cell growth, differentiation and macromolecular synthesis makes the enzymes involved in their synthesis potential targets in the treatment of certain types of cancer and parasitic diseases. Here we present a study on the inhibition of human and Leishmania donovani ODC (ornithine decarboxylase), the first committed enzyme in the polyamine biosynthesis pathway, by APA (1-amino-oxy-3-aminopropane). The present study shows APA to be a potent inhibitor of both human and L. donovani ODC with a K(i) value of around 1.0 nM. We also show that L. donovani ODC binds the substrate, the co-enzyme pyridoxal 5'-phosphate and the irreversible inhibitor alpha-difluoromethylornithine (a curative agent of West African sleeping sickness) with less affinity than human ODC. We have also determined the three-dimensional structure of human ODC in complex with APA, which revealed the mode of the inhibitor binding to the enzyme. In contrast with earlier reports, the structure showed no indication of oxime formation between APA and PLP (pyridoxal 5'-phosphate). Homology modelling suggests a similar mode of binding of APA to L. donovani ODC. A comparison of the ODC-APA-PLP structure with earlier ODC structures also shows that the protease-sensitive loop (residues 158-168) undergoes a large conformational change and covers the active site of the protein. The understanding of the structural mode of APA binding may constitute the basis for the development of more specific inhibitors of L. donovani ODC.
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Affiliation(s)
- Veronica T. Dufe
- *Department of Molecular Biophysics, Lund University, S-221 00 Lund, Sweden
| | - Daniel Ingner
- *Department of Molecular Biophysics, Lund University, S-221 00 Lund, Sweden
| | - Olle Heby
- †Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden
| | - Alex R. Khomutov
- ‡Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Lo Persson
- §Department of Experimental Medical Science, Lund University, S-221 84 Lund, Sweden
- Correspondence may be addressed to either of these authors (email or )
| | - Salam Al-Karadaghi
- *Department of Molecular Biophysics, Lund University, S-221 00 Lund, Sweden
- Correspondence may be addressed to either of these authors (email or )
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Heby O, Persson L, Rentala M. Targeting the polyamine biosynthetic enzymes: a promising approach to therapy of African sleeping sickness, Chagas' disease, and leishmaniasis. Amino Acids 2007; 33:359-66. [PMID: 17610127 DOI: 10.1007/s00726-007-0537-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Accepted: 02/01/2007] [Indexed: 12/11/2022]
Abstract
Trypanosomatids depend on spermidine for growth and survival. Consequently, enzymes involved in spermidine synthesis and utilization, i.e. arginase, ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (AdoMetDC), spermidine synthase, trypanothione synthetase (TryS), and trypanothione reductase (TryR), are promising targets for drug development. The ODC inhibitor alpha-difluoromethylornithine (DFMO) is about to become a first-line drug against human late-stage gambiense sleeping sickness. Another ODC inhibitor, 3-aminooxy-1-aminopropane (APA), is considerably more effective than DFMO against Leishmania promastigotes and amastigotes multiplying in macrophages. AdoMetDC inhibitors can cure animals infected with isolates from patients with rhodesiense sleeping sickness and leishmaniasis, but have not been tested on humans. The antiparasitic effects of inhibitors of polyamine and trypanothione formation, reviewed here, emphasize the relevance of these enzymes as drug targets. By taking advantage of the differences in enzyme structure between parasite and host, it should be possible to design new drugs that can selectively kill the parasites.
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Affiliation(s)
- O Heby
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
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Zhang AH, Rao JN, Zou T, Liu L, Marasa BS, Xiao L, Chen J, Turner DJ, Wang JY. p53-Dependent NDRG1 expression induces inhibition of intestinal epithelial cell proliferation but not apoptosis after polyamine depletion. Am J Physiol Cell Physiol 2007; 293:C379-89. [PMID: 17442733 DOI: 10.1152/ajpcell.00547.2006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Normal intestinal mucosal growth requires polyamines that regulate expression of various genes involved in cell proliferation, growth arrest, and apoptosis. Our previous studies have shown that polyamine depletion stabilizes p53, resulting in inhibition of intestinal epithelial cell (IEC) proliferation, but the exact downstream targets of induced p53 are still unclear. The NDRG1 (N- myc downregulated gene-1) gene encodes a growth-related protein, and its transcription can be induced in response to stress. The current study tests the hypothesis that induced p53 inhibits IEC proliferation by upregulating NDRG1 expression following polyamine depletion. Depletion of cellular polyamines by inhibiting ornithine decarboxylase (ODC) with α-difluoromethylornithine not only induced p53 but also increased NDRG1 transcription as indicated by induction of the NDRG1 promoter activity and increased levels of NDRG1 mRNA and protein, all of which were prevented by using specific p53 siRNA and in cells with a targeted deletion of p53. In contrast, increased levels of cellular polyamines by ectopic expression of the ODC gene decreased p53 and repressed expression of NDRG1. Consistently, polyamine depletion-induced activation of the NDRG1-promoter was decreased when p53-binding sites within the NDRG1 proximal promoter region were deleted. Ectopic expression of the wild-type NDRG1 gene inhibited DNA synthesis and decreased final cell numbers regardless of the presence or absence of endogenous p53, whereas silencing NDRG1 promoted cell growth. However, overexpression of NDRG1 failed to directly induce cell death and to alter susceptibility to apoptosis induced by tumor necrosis factor-α/cycloheximide. These results indicate that NDRG1 is one of the direct mediators of induced p53 following polyamine depletion and that p53-dependent NDRG1 expression plays a critical role in the negative control of IEC proliferation.
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Affiliation(s)
- Ai-Hong Zhang
- Dept. of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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35
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Ignatenko NA, Besselsen DG, Roy UKB, Stringer DE, Blohm-Mangone KA, Padilla-Torres JL, Guillen-R JM, Gerner EW. Dietary putrescine reduces the intestinal anticarcinogenic activity of sulindac in a murine model of familial adenomatous polyposis. Nutr Cancer 2007; 56:172-81. [PMID: 17474863 PMCID: PMC4132951 DOI: 10.1207/s15327914nc5602_8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The nonsteroidal antiinflammatory drug sulindac displays chemopreventive activity in patients with familial adenomatous polyposis (FAP). Sulindac metabolites induce apoptosis in colon tumor cells, in part, by a polyamine-dependent mechanism that can be suppressed with exogenous putrescine. To determine the relevance of this mechanism in animals, we treated Apc(Min/+) mice, a model of human FAP, with sulindac alone or in combination with dietary putrescine. Sulindac increased steady-state RNA levels and enzymatic activity of the polyamine catabolic enzyme spermidine/spermine N(1)-acetyltransferase and intestinal levels of monoacetylspermidine, spermidine, and spermine in the small intestine of mice. Sulindac also decreased the activity of the biosynthetic enzyme ornithine decarboxylase but not adenosylmethionine decarboxylase (AMD). Dietary putrescine increased intestinal putrescine contents, whereas the combination of dietary putrescine and sulindac yielded the highest levels of intestinal putrescine and correlated with a statistically significant reduction in AMD enzyme activity. Dietary putrescine did not statistically significantly increase tumorigenesis, although it significantly increased the grade of adenoma dysplasia (P < 0.05). The effectiveness of sulindac to suppress intestinal carcinogenesis was partially abrogated by dietary putrescine. These data suggest that sulindac exerts at least some of its anticarcinogenic effects in mice via a polyamine-dependent mechanism. Because high concentrations of putrescine can be found in certain dietary components, it may be advantageous to restrict dietary putrescine consumption in patients undergoing treatment with sulindac.
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Affiliation(s)
- Natalia A Ignatenko
- Department of Cell Biology and Anatomy, Arizona Cancer Center, The University of Arizona, Tucson, USA.
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Flamigni F, Stanic' I, Facchini A, Cetrullo S, Tantini B, Borzì RM, Guarnieri C, Caldarera CM. Polyamine biosynthesis as a target to inhibit apoptosis of non-tumoral cells. Amino Acids 2007; 33:197-202. [PMID: 17578652 DOI: 10.1007/s00726-007-0514-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 02/01/2007] [Indexed: 12/18/2022]
Abstract
Growing evidence suggests a role for polyamines in apoptosis, although the relationship appears to be complex. alpha-Difluoromethylornithine (DFMO), a largely used ornithine decarboxylase inhibitor, is cytostatic, hardly cytotoxic and may even increase the resistance of tumour cells to some apoptotic stimuli. This may represent a problem in cancer therapy, where the killing of tumoral cells would be a desired effect, but could be an advantage in other pathological contexts related to an excess of apoptosis, such as cardiovascular diseases, stem cell transplantation, arthritis and infections. In different cellular models, polyamine depletion following treatment with polyamine biosynthesis inhibitors appears to inhibit mitochondrial and death receptor pathways of apoptosis by affecting key proteins. These studies indicate that inhibition of polyamine biosynthesis may prevent or reduce the apoptotic response triggered by a variety of stimuli in non-tumoral cells, such as cardiac cells, stem cells, chondrocytes, macrophages and intestinal epithelial cells.
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Affiliation(s)
- F Flamigni
- Department of Biochemistry "G. Moruzzi", University of Bologna, Bologna, Italy.
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Xiao L, Rao J, Zou T, Liu L, Marasa B, Chen J, Turner D, Passaniti A, Wang JY. Induced JunD in intestinal epithelial cells represses CDK4 transcription through its proximal promoter region following polyamine depletion. Biochem J 2007; 403:573-81. [PMID: 17253961 PMCID: PMC1876376 DOI: 10.1042/bj20061436] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 01/17/2007] [Accepted: 01/25/2007] [Indexed: 02/06/2023]
Abstract
Maintenance of intestinal epithelial integrity requires cellular polyamines that regulate expression of various genes involved in cell proliferation, growth arrest and apoptosis. In prior studies, depletion of cellular polyamines has been shown to stabilize JunD, a member of the AP-1 (activator protein-1) family of transcription factors, leading to inhibition of intestinal epithelial cell proliferation, but the exact downstream targets of induced JunD remain elusive. CDK4 (cyclin-dependent kinase 4) is essential for the G1- to S-phase transition during the cell cycle and its expression is primarily controlled at the transcriptional level. In the present study, we show that induced JunD in IECs (intestinal epithelial cells) is a transcriptional repressor of the CDK4 gene following polyamine depletion. Increased JunD in polyamine-deficient cells was associated with a significant inhibition of CDK4 transcription, as indicated by repression of CDK4-promoter activity and decreased levels of CDK4 mRNA and protein, all of which were prevented by using specific antisense JunD oligomers. Ectopic expression of the wild-type junD also repressed CDK4-promoter activity and decreased levels of CDK4 mRNA and protein without any effect on CDK2 expression. Gel shift and chromatin immunoprecipitation assays revealed that JunD bound to the proximal region of the CDK4-promoter in vitro as well as in vivo, while experiments using different CDK4-promoter mutants showed that transcriptional repression of CDK4 by JunD was mediated through an AP-1 binding site within this proximal sequence of the CDK4-promoter. These results indicate that induced JunD in IECs represses CDK4 transcription through its proximal promoter region following polyamine depletion.
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Key Words
- activator protein-1 (ap-1)
- α-difluoromethylornithine
- growth arrest
- intestinal epithelium
- ornithine decarboxylase
- transcriptional regulation
- ap-1, activator protein-1
- cdk, cyclin-dependent kinase
- chip, chromatin immunoprecipitation
- dfmo, α-difluoromethylornithine
- emsa, electrophoretic mobility-shift assay
- fbs, fetal bovine serum
- gapdh, glyceraldehyde-3-phosphate dehydrogenase
- iec, intestinal epithelial cell
- luc, luciferase
- pbs-t, pbs containing tween 20
- q-pcr, quantitative pcr
- rb, retinoblastoma tumour suppressor protein
- rt, reverse transcriptase
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Affiliation(s)
- Lan Xiao
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Jaladanki N. Rao
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Tongtong Zou
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Lan Liu
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Bernard S. Marasa
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- †Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Jie Chen
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Douglas J. Turner
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Antonino Passaniti
- †Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
| | - Jian-Ying Wang
- *Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- †Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, U.S.A
- ‡Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, U.S.A
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Nakazawa K, Nemoto T, Hata T, Seyama Y, Nagahara S, Sano A, Itoh H, Nagai Y, Kubota S. Single-injection ornithine decarboxylase-directed antisense therapy using atelocollagen to suppress human cancer growth. Cancer 2007; 109:993-1002. [PMID: 17318877 DOI: 10.1002/cncr.22483] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Substantial evidence supports a direct role of ornithine decarboxylase (ODC) in the development and maintenance of human tumors. Although antisense oligonucleotide therapy targeting various genes are useful for cancer treatment, 1 of the major limitations is the problem of delivery. A novel antisense oligonucleotide delivery method is described that allows prolonged sustainment and release of ODC antisense oligonucleotides in vivo using atelocollagen. METHODS The effect of ODC antisense oligonucleotides in the atelocollagen on cell growth of gastrointestinal cancer (MKN 45 and COLO201) and rhabdomyosarcoma (RD) was studied in vitro using a cell-counting method with a hemocytometer. In vivo, the effect of intratumoral, intramuscular, and intraperitoneal single administration of ODC antisense oligonucleotides in the atelocollagen on tumor growth of MKN45, COLO201, and RD cells was studied. ODC activity and polyamine contents were measured. RESULTS In vitro, ODC antisense oligonucleotides in the atelocollagen remarkably suppressed MKN45, COLO201, and RD cell growth. A single administration of antisense oligonucleotides in the atelocollagen via 3 routes remarkably suppressed the growth of MKN45, COLO201, and RD tumor over a period of 35-42 days. CONCLUSIONS As various human cancers significantly express ODC, the results strongly suggest that this new antisense method may be of considerable value for treatment of human cancers.
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Affiliation(s)
- Kunihiko Nakazawa
- Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
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39
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Abstract
The polyamines are growth factors in both normal and cancer cells. As the intracellular polyamine content correlates positively with the growth potential of that cell, the idea that depletion of polyamine content will result in inhibition of cell growth and, particularly tumour cell growth, has been developed over the last 15 years. The polyamine pathway is therefore a target for development of rationally designed, antiproliferative agents. Following the lessons from the single enzyme inhibitors (alpha-difluoromethylornithine DFMO), three generations of polyamine analogues have been synthesised and tested in vitro and in vivo. The analogues are multi-site inhibitors affecting multiple reactions in the pathway and thus prevent the up-regulation of compensatory reactions that have been the downfall of DFMO in anticancer chemotherapy. Although the initial concept was that the analogues may provide novel anticancer drugs, it now seems likely that the analogues will have wider applications in diseases involving hyperplasia.
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Affiliation(s)
- H M Wallace
- Department of Medicine and Therapeutics, School of Medicine and School of Medical Sciences, University of Aberdeen, Aberdeen, UK.
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40
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Shantz LM, Levin VA. Regulation of ornithine decarboxylase during oncogenic transformation: mechanisms and therapeutic potential. Amino Acids 2007; 33:213-23. [PMID: 17443268 DOI: 10.1007/s00726-007-0531-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Accepted: 02/01/2007] [Indexed: 01/10/2023]
Abstract
The activity of ornithine decarboxylase (ODC(1)), the first enzyme in polyamine biosynthesis, is induced during carcinogenesis by a variety of oncogenic stimuli. Intracellular levels of ODC and the polyamines are tightly controlled during normal cell growth, and regulation occurs at the levels of transcription, translation and protein degradation. Several known proto-oncogenic pathways appear to control ODC transcription and translation, and dysregulation of pathways downstream of ras and myc result in the constitutive elevation of ODC activity that occurs with oncogenesis. Inhibition of ODC activity reverts the transformation of cells in vitro and reduces tumor growth in several animal models, suggesting high levels of ODC are necessary for the maintenance of the transformed phenotype. The ODC irreversible inactivator DFMO has proven to be not only a valuable tool in the study of ODC in cancer, but also shows promise as a chemopreventive and chemotherapeutic agent in certain types of malignancies.
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Affiliation(s)
- L M Shantz
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
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41
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Ulrich S, Huwiler A, Loitsch S, Schmidt H, Stein JM. De novo ceramide biosynthesis is associated with resveratrol-induced inhibition of ornithine decarboxylase activity. Biochem Pharmacol 2007; 74:281-9. [PMID: 17521618 DOI: 10.1016/j.bcp.2007.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 03/30/2007] [Accepted: 04/02/2007] [Indexed: 11/25/2022]
Abstract
Previous studies could demonstrate, that the naturally occuring polyphenol resveratrol inhibits cell growth of colon carcinoma cells at least in part by inhibition of protooncogene ornithine decarboxylase (ODC). The objective of this study was to provide several lines of evidence suggesting that the induction of ceramide synthesis is involved in this regulatory mechanisms. Cell growth was determined by BrdU incorporation and crystal violet staining. Ceramide concentrations were detected by HPLC-coupled mass-spectrometry. Protein levels were examined by Western blot analysis. ODC activity was assayed radiometrically measuring [(14)CO(2)]-liberation. A dominant-negative PPARgamma mutant was transfected in Caco-2 cells to suppress PPARgamma-mediated functions. Antiproliferative effects of resveratrol closely correlate with a dose-dependent increase of endogenous ceramides (p<0.001). Compared to controls the cell-permeable ceramide analogues C2- and C6-ceramide significantly inhibit ODC-activity (p<0.001) in colorectal cancer cells. C6-ceramide further diminished protein levels of protooncogenes c-myc (p<0.05) and ODC (p<0.01), which is strictly related to the ability of ceramides to inhibit cell growth in a time- and dose-dependent manner. These results were further confirmed using inhibitors of sphingolipid metabolism, where only co-incubation with a serine palmitoyltransferase (SPT) inhibitor could significantly counteract resveratrol-mediated actions. These data suggest that the induction of ceramide de novo biosynthesis but not hydrolysis of sphingomyelin is involved in resveratrol-mediated inhibition of ODC. In contrast to the regulation of catabolic spermidine/spermine acetyltransferase by resveratrol, inhibitory effects on ODC occur PPARgamma-independently, indicating independent pathways of resveratrol-action. Due to our findings resveratrol could show great chemopreventive and therapeutic potential in the treatment of colorectal cancers.
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Affiliation(s)
- Sandra Ulrich
- First Department of Internal Medicine-ZAFES, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
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42
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Abstract
The mammalian intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through strict regulation of epithelial cell proliferation, growth arrest, and apoptosis. Polyamines are necessary for normal intestinal mucosal growth and decreasing cellular polyamines inhibits cell proliferation and disrupts epithelial integrity. An increasing body of evidence indicates that polyamines regulate intestinal epithelial cell renewal by virtue of their ability to modulate expression of various genes and that growth inhibition following polyamine depletion results primarily from the activation of growth-inhibiting genes rather than a simple decrease in expression of growth-promoting genes. In this review article, we will focus on changes in expression of growth-inhibiting genes following polyamine depletion and further analyze in some detail the mechanisms through which mRNA stability is regulated by RNA-binding proteins.
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Affiliation(s)
- J-Y Wang
- Cell Biology Group, Departments of Surgery and Pathology, University of Maryland School of Medicine and Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, USA.
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43
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Bastida CM, Cremades A, Castells MT, López-Contreras AJ, López-García C, Sánchez-Mas J, Peñafiel R. Sexual dimorphism of ornithine decarboxylase in the mouse adrenal: influence of polyamine deprivation on catecholamine and corticoid levels. Am J Physiol Endocrinol Metab 2007; 292:E1010-7. [PMID: 17148758 DOI: 10.1152/ajpendo.00316.2006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adrenal sexual dimorphism is thought to be important in explaining sex-related differences regarding prevalent diseases and the responses to stress and drugs. We report here that in CD1 mice there is marked sexual dimorphism affecting not only gland size and corticoid hormone secretion but also adrenal ornithine decarboxylase (ODC), polyamine, and catecholamine levels in which testosterone appears to be a major determinant. Our results show that adrenal weight, ODC activity, and corticosterone and aldosterone secretion were higher in female than in male mice and that orchidectomy brought these male parameters closer to the values found in females. mRNA levels of steroidogenic proteins SF-1, Dax-1, steroid 21-hydroxylase, and aldosterone synthase appeared to be slightly higher in female than in male adrenals. Immunocytochemical analysis of adrenal ODC revealed that immunoreactivity was higher in females than in males and was located mainly in the cortical cells, and especially in zona glomerulosa, whereas no sex differences in ODC mRNA levels were observed. These results suggest that sex-associated differences in the expression of ODC in the mouse adrenal gland appear to be related mainly to posttranscriptional mechanisms. Combination treatment of mice with alpha-difluoromethylornithine (a suicide inhibitor of ODC) and a polyamine-deficient diet produced a marked decrease in adrenal polyamine and catecholamine levels and a significant reduction in plasma corticosterone and aldosterone concentrations that were not associated with a decrease in the mRNA levels of steroidogenic proteins. All of these data suggest a relevant role for testosterone, ODC, and polyamines in the mouse adrenal function.
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Affiliation(s)
- Carmen M Bastida
- Department of Pharmacology, Faculty of Medicine, University of Murcia, Murcia, Spain
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44
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Gerner EW, Meyskens FL, Goldschmid S, Lance P, Pelot D. Rationale for, and design of, a clinical trial targeting polyamine metabolism for colon cancer chemoprevention. Amino Acids 2007; 33:189-95. [PMID: 17396214 DOI: 10.1007/s00726-007-0515-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 02/01/2007] [Indexed: 11/27/2022]
Abstract
Polyamine metabolic genes are downstream targets of several genes commonly mutated in colon adenomas and cancers. Inhibitors of ornithine decarboxylase, such as difluoromethylornithine (DFMO), and agents that stimulate polyamine acetylation and export, such as non-steroidal anti-inflammatory drugs (NSAIDS), act at least additively to arrest growth in human cell models and suppress intestinal carcinogenesis in mice. These preclinical studies provided the rationale for colon cancer prevention trials in humans. A Phase IIb clinical study comparing the combination of DFMO and the NSAID sulindac versus placebo was conducted. Endpoints were colorectal tissue polyamine and prostaglandin E2 contents and overall toxicity to participants. Participants in the Phase IIb study served as a vanguard for a randomized, placebo-controlled prospective Phase III trial of the combination of DFMO and sulindac with the primary study endpoint the prevention of colon polyps. Seventy percent of participants will have completed the three years of treatment in December 2006.
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Affiliation(s)
- E W Gerner
- Arizona Cancer Center, Department of Cell Biology and Anatomy, The University of Arizona, Tucson, AZ 85724, USA.
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Mello CF, Rubin MA, Sultana R, Barron S, Littleton JM, Butterfield DA. Difluoromethylornithine decreases long-lasting protein oxidation induced by neonatal ethanol exposure in the hippocampus of adolescent rats. Alcohol Clin Exp Res 2007; 31:887-94. [PMID: 17386069 DOI: 10.1111/j.1530-0277.2007.00369.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ethanol exposure and withdrawal during central nervous system development can cause oxidative stress and produce severe and long-lasting behavioral and morphological alterations in which polyamines seem to play an important role. However, it is not known if early ethanol exposure causes long-lasting protein oxidative damage and if polyamines play a role in such a deleterious effect of ethanol. METHODS In this study we investigated the effects of early ethanol exposure (6 g/kg/d, by gavage), from postnatal day (PND) 1 to 8, and of the administration of difluoromethylornithine (DFMO, 500 mg/kg, i.p., on PND 8), a polyamine biosynthesis inhibitor, on the extent of oxidative modification of proteins. Indices of oxidative modification of proteins included protein carbonyls, 3-nitrotyrosine (3-NT), and protein bound 4-hydroxynonenal (HNE) in the hippocampus, cerebellum, hypothalamus, striatum, and cerebral cortex of Sprague-Dawley rats at PND 40. RESULTS Both ethanol and DFMO administration alone increased protein carbonyl immunoreactivity in the hippocampus at PND 40, but the combination of DFMO and ethanol resulted in no effect on protein carbonyl levels. No alterations in the content of protein-bound HNE, 3-NT, or carbonyl were found in any other cerebral structure. CONCLUSIONS These results suggest that the hippocampus is selectively affected by early ethanol exposure and by polyamine synthesis inhibition. In addition, the results suggest a role for polyamines in the long-lasting increase of protein carbonyls induced by ethanol exposure and withdrawal.
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Affiliation(s)
- Carlos Fernando Mello
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
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Chung WY, Park JH, Kim MJ, Kim HO, Hwang JK, Lee SK, Park KK. Xanthorrhizol inhibits 12-O-tetradecanoylphorbol-13-acetate-induced acute inflammation and two-stage mouse skin carcinogenesis by blocking the expression of ornithine decarboxylase, cyclooxygenase-2 and inducible nitric oxide synthase through mitogen-activated protein kinases and/or the nuclear factor- B. Carcinogenesis 2007; 28:1224-31. [PMID: 17234720 DOI: 10.1093/carcin/bgm005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Xanthorrhizol is an active component isolated from Curcuma xanthorrhiza Roxb. (Zingiberaceae) that is traditionally used in Indonesia for medicinal purposes. In the present study, we found that the topical application of xanthorrhizol before 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment significantly inhibits TPA-induced mouse ear edema and TPA-induced tumor promotion in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated ICR mouse skin. The topical application of xanthorrhizol following the induction of papillomas with TPA-induced hyperplasia and dysplasia also reduced tumor multiplicity and incidence in DMBA-initiated mouse skin. To further elucidate the molecular mechanisms underlying the antitumor-promoting activity of xanthorrhizol, its effect on the TPA-induced expression of ornithine decarboxylase (ODC), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) and the upstream signaling molecules controlling these proteins were explored in mouse skin. The pre-treatment with xanthorrhizol inhibited the expression of ODC, iNOS and COX-2 proteins and nuclear factor-kappaB (NF-kappaB) activation in both mouse skin with TPA-induced acute inflammation and DMBA-initiated mouse skin promoted by TPA for 19 weeks. When mouse skin was treated after TPA-induced production of papillomas, xanthorrhizol remarkably suppressed the expression of ODC, iNOS and COX-2 and inhibited the activation of NF-kappaB. Furthermore, western blot analysis showed that xanthorrhizol suppressed the activation of extracellular signal-regulated protein kinase, p38, c-Jun-N-terminal kinase and Akt in mice after topical application for 6 weeks following the induction of papillomas. Taken together, the present study demonstrates that xanthorrhizol not only delays or inhibits tumor formation, but also reverses the carcinogenic process at pre-malignant stages by reducing the protein levels of ODC, iNOS and COX-2 regulated by the NF-kappaB, mitogen-activated protein kinases and/or Akt.
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Affiliation(s)
- Won Yoon Chung
- Department of Oral Biology, Yonsei University, College of Dentistry, Seodaemoon-Gu, Seoul, Korea
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47
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Orlovskiĭ AA. [Characteristics of polyamine biosynthesis regulation and tumor growth rate in hormone-dependant grafted breast tumors of mice and rats]. Lik Sprava 2007:68-75. [PMID: 17682520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Effect of the inhibitors of polyamines biosynthesis on completely or partially hormone-dependant breast tumors (mouse Ca755 carcinoma and Walker W-256 carcinosarcoma) is essentially special: in contrary to hormone-dependant tumors, this effect may be not only breaking but stimulating as well. Change-over from one to another mode of reaction is conditioned, most probable, by hormonal status, which is determined by one or another estral cycle phase. Biochemical mechanisms of this change-over are closely connected with polyamines metabolism, namely the degree of polyamines (especially spermine) interconvertion and physiological reactivity level of the system controlling expression of ornithin-decarboxilase. At that, the first of these pathways is predominant for completely hormone-dependant Ca755 and the second one -for partially hormone-dependant W-256.
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MESH Headings
- Adenocarcinoma/drug therapy
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Animals
- Antineoplastic Agents/administration & dosage
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Biogenic Polyamines/antagonists & inhibitors
- Biogenic Polyamines/biosynthesis
- Carcinoma 256, Walker/drug therapy
- Carcinoma 256, Walker/metabolism
- Carcinoma 256, Walker/pathology
- Cell Line, Tumor
- Eflornithine/administration & dosage
- Eflornithine/pharmacology
- Eflornithine/therapeutic use
- Female
- Guanidines/administration & dosage
- Guanidines/pharmacology
- Guanidines/therapeutic use
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/metabolism
- Mammary Neoplasms, Experimental/pathology
- Mice
- Neoplasm Transplantation
- Neoplasms, Hormone-Dependent/drug therapy
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Ornithine Decarboxylase Inhibitors
- Rats
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48
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Ivanov IP, Pittman AJ, Chien CB, Gesteland RF, Atkins JF. Novel antizyme gene in Danio rerio expressed in brain and retina. Gene 2007; 387:87-92. [PMID: 17049757 DOI: 10.1016/j.gene.2006.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/03/2006] [Accepted: 08/09/2006] [Indexed: 11/21/2022]
Abstract
The synthesis of the protein antizyme requires a +1 ribosomal frameshift event. The frameshifting serves as a regulatory sensor. Antizyme homologs have been identified in diverse organisms ranging from yeast to human and characterized in a disparate subset. Most vertebrates have multiple antizyme paralogs. Here we present identification in the zebrafish Danio rerio of a heretofore unknown member of the antizyme gene family. This novel antizyme does not correspond to any of the known orthologous groups in vertebrates and unlike most other antizymes is preferentially expressed in the retinal ganglion cell layer of the eye. In addition to the retina, it is also expressed in the brain and somites.
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Affiliation(s)
- Ivaylo P Ivanov
- Department of Human Genetics, University of Utah, Utah 84112-5330, United States
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49
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Williams PG, Asolkar RN, Kondratyuk T, Pezzuto JM, Jensen PR, Fenical W. Saliniketals A and B, bicyclic polyketides from the marine actinomycete Salinispora arenicola. J Nat Prod 2007; 70:83-8. [PMID: 17253854 DOI: 10.1021/np0604580] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
An extensive study of the secondary metabolites produced by several strains of the marine actinomycete Salinispora arenicola has led to the isolation of two unusual bicyclic polyketides, saliniketals A and B (1, 2). The structures, which contain a new 1,4-dimethyl-2,8-dioxabicyclo[3.2.1]octan-3-yl ring, were assigned mainly by 2D NMR spectroscopic methods. Unexpectedly, chemical derivatization of saliniketal A with Mosher's acid chloride resulted in a functional group interconversion of an unsaturated primary amide to the corresponding nitrile in a quantitative yield under unusually mild conditions. Saliniketals A and B were found to inhibit ornithine decarboxylase induction, an important target for the chemoprevention of cancer, with IC50 values of 1.95 +/- 0.37 and 7.83 +/- 1.2 microg/mL, respectively.
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Affiliation(s)
- Philip G Williams
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California - San Diego, La Jolla, California 92093-0204, USA
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50
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Gilad GM, Gilad VH. Astroglia growth retardation and increased microglia proliferation by lithium and ornithine decarboxylase inhibitor in rat cerebellar cultures: Cytotoxicity by combined lithium and polyamine inhibition. J Neurosci Res 2007; 85:594-601. [PMID: 17171700 DOI: 10.1002/jnr.21152] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Lithium, the most prevalent treatment for manic-depressive illness, might have a neuroprotective effect after brain injury. In culture, lithium can exert neurotoxic effects associated with reduction in polyamine synthesis but neuroprotective effects as cultured neurons mature. Cumulative evidence suggests that lithium may exert some of its effects on neurons indirectly, by initially acting on glial cells. We used rat cerebellar cultures to ascertain the effects of lithium on ornithine decarboxylase (ODC) activity, the enzyme catalyzing the first step in polyamine synthesis, and to compare effects of lithium with those of the ODC inhibitor alpha-difluoromethylornithine (DFMO) on neuron survival and glial growth. Switching cultures from high (25 mM) to low (5 mM) KCl concentrations served as the traumatic neuronal insult. The results indicate the following. 1) Whereas high depolarizing KCl concentration enhances neuron survival, it inhibits astroglial growth. 2) Lithium (LiCl; 1-5 mM) enhances neuronal survival but inhibits astroglial growth. 3) Lithium treatment leads to reduced ODC activity. 4) DFMO enhances neuron survival but inhibits astroglial growth. 5) Lithium and DFMO lead to transformation of astroglia from epithelioid (flat) to process-bearing morphology and to increased numbers of microglia. 6) Combined lithium plus DFMO treatment is cytolethal to both neurons and glia in culture. In conclusion, lithium treatment results in growth retardation and altered cell morphology of cultured astroglia and increased microglia proliferation, and these effects may be associated with inhibition of polyamine synthesis. This implies that direct effects on astrocytes and microglia may contribute to the effects of lithium on neurons.
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