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Lin C, Zhang Y, Liao J, Cui S, Gao Z, Han W. Effect of photodynamic therapy mediated by hematoporphyrin derivatives on small cell lung cancer H446 cells and bronchial epithelial BEAS-2B cells. Lasers Med Sci 2024; 39:65. [PMID: 38368311 PMCID: PMC10874342 DOI: 10.1007/s10103-024-04013-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 08/30/2023] [Accepted: 02/02/2024] [Indexed: 02/19/2024]
Abstract
To investigate the effects of photodynamic therapy (PDT) mediated by hematoporphyrin derivatives (HPD) on the proliferation of small cell lung cancer H446 cells and bronchial epithelial BEAS-2B cells. H446 cells and BEAS-2B cells were cultured in vitro with different concentrations of HPD(0, 5, 10, 12, 15, 20 μg/mL) for 4 h, and then irradiated with 630 nm laser with different energy densities (0, 25, 50, 75, 100 mW/cm2). Cell viability of H446 cells and BEAS-2B cells were detected by CCK8 assay. The cell apoptosis was observed with Annexin V-FTTC/PI double staining and Hoechst 33258. The RT-PCR examination was applied to detect the transcriptional changes of the mRNA of Bax、Bcl-2, and Caspase-9. The results of CCK8 showed that when the HPD was 15 μg/mL and the laser power density reached 50 mW/cm2, the cell viability was significantly decreased compared with the black control group. Hoechst 33258 staining showed that with the increase of HPD concentration, the cell density was reduced, and apoptotic cells increased. Flow cytometry assay revealed that the apoptotic rates of the HPD-PDT group of H446 cells and BEAS-2B cells were significantly different from those of the blank control group. The RT-PCR examination showed that the expression levels of Bax and Caspase-9 mRNA in the HPD-PDT group were up-regulated, while the expression levels of Bcl-2 mRNA were down-regulated significantly. HPD-PDT can inhibit H446 cells and BEAS-2B cells growth. The mechanism may be related to up-regulating the expression levels of Bax and Caspase-9 mRNA and down-regulating the expression levels of Bcl-2 mRNA.
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Affiliation(s)
- Cunzhi Lin
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Yuanyuan Zhang
- Department of Respiratory and Critical Care Medicine, Yantai Yuhuangding Hospital, Yan Tai, 264001, China
| | - Jiemei Liao
- Department of Respiratory and Critical Care Medicine, Xiangtan Central Hospital, Xiangtan, 411199, China
| | - Shichao Cui
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Zhe Gao
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China
| | - Weizhong Han
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Qingdao University, Qingdao, 266003, China.
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Zhou Q, Wu WW, Yu CL, Wang P, Wen XQ, Chen BL, Zhang Y, Zhuang M, Zhang MY, Zhang HY, Zhang JW. Saikosaponin A Inhibits Growth of Human Bladder Carcinoma T24 and 5637 Cells Both in Vitro and in Vivo. Biol Pharm Bull 2022; 45:863-871. [PMID: 35491088 DOI: 10.1248/bpb.b21-01025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Indexed: 09/08/2023]
Abstract
Saikosaponin A (SSA)-a natural compound extracted from Radix bupleuri-possesses antitumor properties in several types of carcinomas. However, the role of SSA on bladder cancer and the mechanisms remain unclear. In this study, we have described the effect of SSA on human bladder cancer cell lines T24 and 5637 in the context of the regulation of mitochondrial pathways of apoptosis. In vitro, the Cell Counting Kit-8 (CCK-8) assay and cell wound healing assays were used to determine the proliferative effect of SSA treatment. Flow cytometry and Western blotting were performed to evaluate the apoptosis and related mechanisms. To further confirm that apoptosis is mediated through Caspase activation, Hoechst 33258 fluorescence staining assay was done after cells were treated with SSA and caspase inhibitor-Z-VAD-FMK. In vivo, an orthotopic xenograft mice model was adopted to evaluate the effect of SSA. The tumors were analyzed by hematoxylin-eosin (H&E) staining, immunohistochemical analysis, and Western blotting. In vitro, the results with CCK-8 assay showed obvious SSA-induced suppression in cell growth in a dose- and time-dependent manner. Flow cytometry analysis, Hoechst 33258 fluorescence staining assay and the assessment of the changes in the B-cell lymphoma 2 (Bcl-2) family protein expression level revealed that SSA could significantly induce cell apoptosis, which was associated with apoptosis via the mitochondrial pathways. In vivo, the results revealed a reduction in cell proliferation. In conclusion, our data suggest that SSA inhibits the growth of bladder cancer cells by activating the mitochondrial apoptosis pathway and inducing cell apoptosis.
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Affiliation(s)
- Qian Zhou
- School of Pharmacy, North Sichuan Medical College
| | - Wei-Wei Wu
- Clinical Laboratory, Maternal and Child Health Care Hospital of Shandong Province
| | - Chun-Lei Yu
- School of Pharmacy, North Sichuan Medical College
| | - Peng Wang
- School of Pharmacy, North Sichuan Medical College
| | | | - Bi-Ling Chen
- School of Pharmacy, North Sichuan Medical College
| | - Ying Zhang
- School of Medical Imaging, North Sichuan Medical College
| | - Min Zhuang
- School of Medical Imaging, North Sichuan Medical College
| | | | - Hao-Yuan Zhang
- School of Clinical Medicine, North Sichuan Medical College
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Nagaraju B, Kovvuri J, Kumar CG, Routhu SR, Shareef MA, Kadagathur M, Adiyala PR, Alavala S, Nagesh N, Kamal A. Synthesis and biological evaluation of pyrazole linked benzothiazole-β-naphthol derivatives as topoisomerase I inhibitors with DNA binding ability. Bioorg Med Chem 2019; 27:708-720. [PMID: 30679134 DOI: 10.1016/j.bmc.2019.01.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [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: 08/29/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 11/17/2022]
Abstract
A series of new pyrazole linked benzothiazole-β-naphthol derivatives were designed and synthesized using a simple, efficient and ecofriendly route under catalyst-free conditions in good to excellent yields. These derivatives were evaluated for their cytotoxicity on selected human cancer cell lines. Among those, the derivatives 4j, 4k and 4l exhibited considerable cytotoxicity with IC50 values ranging between 4.63 and 5.54 µM against human cervical cancer cells (HeLa). Structure activity relationship was elucidated by varying different substituents on benzothiazoles and pyrazoles. Further, flow cytometric analysis revealed that these derivatives induced cell cycle arrest in G2/M phase and spectroscopic studies such as UV-visible, fluorescence and circular dichroism studies showed that these derivatives exhibited good DNA binding affinity. Additionally, these derivatives can effectively inhibit the topoisomerase I activity. Viscosity studies and molecular docking studies demonstrated that the derivatives bind with the minor groove of the DNA.
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Affiliation(s)
- Burri Nagaraju
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India
| | - Jeshma Kovvuri
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India
| | - C Ganesh Kumar
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India.
| | - Sunitha Rani Routhu
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India
| | - Md Adil Shareef
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India
| | - Manasa Kadagathur
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India
| | - Praveen Reddy Adiyala
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India
| | - Sateesh Alavala
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India
| | - Narayana Nagesh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500007, Telangana, India.
| | - Ahmed Kamal
- Medicinal Chemistry and Biotechnology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India; School of Pharmaceutical Education and Research, (SPER) Jamia Hamdard, New Delhi 110062, India.
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Abstract
Optimal imaging methods are necessary in order to perform a detailed characterization of thick tissue samples from either native or engineered tissues. Tissue-engineered substitutes are featuring increasing complexity including multiple cell types and capillary-like networks. Therefore, technical approaches allowing the visualization of the inner structural organization and cellular composition of tissues are needed. This chapter describes an optical clearing technique which facilitates the detailed characterization of whole-mount samples from skin and adipose tissues (ex vivo tissues and in vitro tissue-engineered substitutes) when combined with spectral confocal microscopy and quantitative analysis on image renderings.
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Affiliation(s)
- Dominique Mayrand
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, CRCHU de Québec-Université Laval, Québec, QC, Canada
- Department of Surgery, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Julie Fradette
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, CRCHU de Québec-Université Laval, Québec, QC, Canada.
- Department of Surgery, Faculty of Medicine, Université Laval, Québec, QC, Canada.
- CMDGT/LOEX, Aile-R, Pavilion Hôpital Enfant-Jésus, CRCHU de Québec-Université Laval, Québec, QC, Canada.
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Patil R, Kulshrestha A, Tikoo A, Fleetwood S, Katara G, Kolli B, Seibel W, Gilman-Sachs A, Patil SA, Beaman KD. Identification of Novel Bisbenzimidazole Derivatives as Anticancer Vacuolar (H⁺)-ATPase Inhibitors. Molecules 2017; 22:molecules22091559. [PMID: 28926955 PMCID: PMC6151825 DOI: 10.3390/molecules22091559] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/31/2017] [Accepted: 09/13/2017] [Indexed: 01/22/2023] Open
Abstract
The vacuolar (H+)-ATPases (V-ATPases) are a family of ATP-driven proton pumps and they have been associated with cancer invasion, metastasis, and drug resistance. Despite the clear involvement of V-ATPases in cancer, the therapeutic use of V-ATPase-targeting small molecules has not reached human clinical trials to date. Thus, V-ATPases are emerging as important targets for the identification of potential novel therapeutic agents. We identified a bisbenzimidazole derivative (V) as an initial hit from a similarity search using four known V-ATPase inhibitors (I–IV). Based on the initial hit (V), we designed and synthesized a focused set of novel bisbenzimidazole analogs (2a–e). All newly prepared compounds have been screened for selected human breast cancer (MDA-MB-468, MDA-MB-231, and MCF7) and ovarian cancer (A2780, Cis-A2780, and PA-1) cell lines, along with the normal breast epithelial cell line, MCF10A. The bisbenzimidazole derivative (2e) is active against all cell lines tested. Remarkably, it demonstrated high cytotoxicity against the triple-negative breast cancer (TNBC) cell line, MDA-MB-468 (IC50 = 0.04 ± 0.02 μM). Additionally, it has been shown to inhibit the V-ATPase pump that is mainly responsible for acidification. To the best of our knowledge the bisbenzimidazole pharmacophore has been identified as the first V-ATPase inhibitor in its class. These results strongly suggest that the compound 2e could be further developed as a potential anticancer V-ATPase inhibitor for breast cancer treatment.
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Affiliation(s)
- Renukadevi Patil
- Pharmaceutical Sciences Department, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Arpita Kulshrestha
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Anjali Tikoo
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Sara Fleetwood
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Gajendra Katara
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Bala Kolli
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - William Seibel
- Division of Oncology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
| | - Alice Gilman-Sachs
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Shivaputra A Patil
- Pharmaceutical Sciences Department, College of Pharmacy, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Kenneth D Beaman
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
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6
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Ranjan N, Arya DP. Linker dependent intercalation of bisbenzimidazole-aminosugars in an RNA duplex; selectivity in RNA vs. DNA binding. Bioorg Med Chem Lett 2016; 26:5989-5994. [PMID: 27884695 PMCID: PMC6201841 DOI: 10.1016/j.bmcl.2016.10.076] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 09/03/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/08/2023]
Abstract
Neomycin and Hoechst 33258 are two well-known nucleic acid binders that interact with RNA and DNA duplexes with high affinities respectively. In this manuscript, we report that covalent attachment of bisbenzimidazole unit derived from Hoechst 33258 to neomycin leads to intercalative binding of the bisbenzimidazole unit (oriented at 64-74° with respected to the RNA helical axis) in a linker length dependent manner. The dual binding and intercalation of conjugates were supported by thermal denaturation, CD, LD and UV-Vis absorption experiments. These studies highlight the importance of linker length in dual recognition by conjugates, for effective RNA recognition, which can lead to novel ways of recognizing RNA structures. Additionally, the ligand library screens also identify DNA and RNA selective compounds, with compound 9, containing a long linker, showing a 20.3°C change in RNA duplex Tm with only a 13.0°C change in Tm for the corresponding DNA duplex. Significantly, the shorter linker in compound 3 shows almost the reverse trend, a 23.8°C change in DNA Tm, with only a 9.1°C change in Tm for the corresponding RNA duplex.
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Affiliation(s)
- Nihar Ranjan
- Laboratory of Bioorganic and Medicinal Chemistry, Department of Chemistry, Clemson University, Clemson, SC 29634, United States
| | - Dev P Arya
- Laboratory of Bioorganic and Medicinal Chemistry, Department of Chemistry, Clemson University, Clemson, SC 29634, United States.
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Dariĭ MV, Rakhimova AR, Tashlitskiĭ VN, Kostiuk SV, Veĭko NN, Ivanov AA, Zhuze AL, Gromova ES. [Dimeric bisberzimidazoles: cytotoxicity and effects on DNA methylation in normal and cancer human cells]. Mol Biol (Mosk) 2013; 47:292-301. [PMID: 23808164 DOI: 10.7868/s0026898413020043] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cancer cells are characterized by the hypermethylation of promoter regions of tumor suppressor genes. DNA methyltransferase inhibitors cause re-activation of these genes that allows considering DNA methyltransferases as targets for anticancer therapy. As it was previously shown by us, dimeric bisbenzimidazoles, DB(n), differing in length of the oligomethylene linker between the two bisbenzimidazole fragments (n--number of methylene groups in linker) effectively inhibit the methylation of DNA duplexes by murine methyltransferase Dnmt3a. Here, the cytotoxicity of some of these compounds, their penetration into cells and influence on the methylation of genomic DNA in fetal lung fibroblasts line F-977 and cervical cancer cells HeLa have been studied. In the 0-60 microM concentration range, only the DB(11) displayed a significant toxic effect on the normal cells, whereas the effect of DB(n) investigated on the cancer cells was not significant. Interestingly, the DB(1) and DB(3) to a small extent stimulate the proliferation of HeLa and F-977 cells, respectively. DB(1) and DB(3) display ability to penetrate into the nucleus of HeLa and F-977 cells and accumulate in various parts of the nuclei. DB(11) is not able to penetrate into the nuclei of these cells. The incubation of F-977 cells with 26 microM of DB(1) or DB(3) led to a decrease of the methylation of 18S rRNA gene, which is located in the region of DB(1) and DB(3) accumulation. A similar effect produces the same concentration of DB (3) in the F-977 cells. However, the overall level of genomic DNA methylation was not changed. These data suggest that DB(n) can be directed to act on specific genes demethylation and in the future may selectively inhibit the proliferation of cancer cells.
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Lisitsina ES, Durandin NA, Ivanov AA, Strel'tsov SA, Susova OI, Shtil' AA, Zhuze AL, Kuz'min VA. [Characteristics of complex formation between monomeric and dimeric bisbenzimidazoles and AT-containing polynucleotide]. Mol Biol (Mosk) 2012; 46:922-927. [PMID: 23350239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Double-stranded DNA is a one of the most important intracellular anticancer agent targets. Disturbance of DNA functions as well as DNA structure lead to disorder of such processes as transcription and/or translation thus inducing tumor cells death. Complex formation between novel dimeric bisbenzimidazole DB(7) and poly(dA-dT) duplex in comparison with known monomeric bisbenzimidazole MB(Ac) was investigated in this study. DB(7)-poly(dA-dT) binding constant was determined by fluorescence spectroscopy using Scatchard plot and it values 1.18 x 10(8) M(-1) that is two orders of magnitude larger than MB(Ac) one (2.06 x 10(6) M(-1)). Thus, from findings mentioned above it could be concluded that the presence of two bisbenzimidazole moieties in the ligand structure significantly increases its affinity to the polynucleotide which motivates the synthesis of new potential anticancer drugs based on dimeric bisbenzimidazoles.
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Wang XJ, Chu NY, Wang QH, Liu C, Jiang CG, Wang XY, Ikejima T, Cheng MS. Newly synthesized bis-benzimidazole derivatives exerting anti-tumor activity through induction of apoptosis and autophagy. Bioorg Med Chem Lett 2012; 22:6297-300. [PMID: 22959518 DOI: 10.1016/j.bmcl.2012.06.102] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/21/2012] [Accepted: 06/29/2012] [Indexed: 11/19/2022]
Abstract
In this study, a new series of bis-benzimidazole derivatives were designed and synthesized. Most of these new compounds showed significant anti-tumor activity in vitro compared to Hoechst 33258. Among them, the most potent compound 8 had the IC(50) values of 0.56μM for HL60 (Human promyelocytic leukemia cells) tumor cell line and 0.58μM for U937 (Human leukemic monocyte lymphoma cells) tumor cell line. Subsequent toxicity study on human peripheral blood mononuclear cells (PBMC) showed that compound 8 exhibited less toxicity than 5-FU. We also found that apoptosis and autophagy were simultaneously induced by compound 8 in HL60 cells, and inhibition of autophagy by 3-MA decreased compound 8-induced apoptosis, indicating that they acted in synergy to exert tumor cell death.
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Affiliation(s)
- Xiu-Jun Wang
- Key Laboratory of Structure-Based Drugs Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, PR China
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Kaur N, Ranjan A, Tiwari V, Aneja R, Tandon V. DMA, a bisbenzimidazole, offers radioprotection by promoting NFκB transactivation through NIK/IKK in human glioma cells. PLoS One 2012; 7:e39426. [PMID: 22745752 PMCID: PMC3382165 DOI: 10.1371/journal.pone.0039426] [Citation(s) in RCA: 7] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 05/21/2012] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Ionizing radiation (IR) exposure often occurs for human beings through occupational, medical, environmental, accidental and/or other sources. Thus, the role of radioprotector is essential to overcome the complex series of overlapping responses to radiation induced DNA damage. METHODS AND RESULTS Treatment of human glioma U87 cells with DMA (5- {4-methylpiperazin-1-yl}-2-[2'-(3, 4-dimethoxyphenyl)-5'-benzimidazolyl] in the presence or absence of radiation uncovered differential regulation of an array of genes and proteins using microarray and 2D PAGE techniques. Pathway construction followed by relative quantitation of gene expression of the identified proteins and their interacting partners led to the identification of MAP3K14 (NFκB inducing kinase, NIK) as the candidate gene affected in response to DMA. Subsequently, over expression and knock down of NIK suggested that DMA affects NFκB inducing kinase mediated phosphorylation of IKKα and IKKβ both alone and in the presence of ionizing radiation (IR). The TNF-α induced NFκB dependent luciferase reporter assay demonstrated 1.65, 2.26 and 3.62 fold increase in NFκB activation at 10, 25 and 50 µM DMA concentrations respectively, compared to control cells. This activation was further increased by 5.8 fold in drug + radiation (50 µM +8.5 Gy) treated cells in comparison to control. We observed 51% radioprotection in control siRNA transfected cells that attenuated to 15% in siRNA NIK treated U87 cells, irradiated in presence of DMA at 24 h. CONCLUSIONS Our studies show that NIK/IKK mediated NFκB activation is more intensified in cells over expressing NIK and treated with DMA, alone or in combination with ionizing radiation, indicating that DMA promotes NIK mediated NFκB signaling. This subsequently leads to the radioprotective effect exhibited by DMA.
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Affiliation(s)
- Navrinder Kaur
- Dr B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Atul Ranjan
- Department of Chemistry, University of Delhi, Delhi, India
| | - Vinod Tiwari
- Department of Chemistry, University of Delhi, Delhi, India
| | - Ritu Aneja
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Vibha Tandon
- Department of Chemistry, University of Delhi, Delhi, India
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Chen SM, Liu JP, Zhou JX, Chen C, Deng YQ, Wang Y, Tao ZZ. Suppression of the notch signaling pathway by γ-secretase inhibitor GSI inhibits human nasopharyngeal carcinoma cell proliferation. Cancer Lett 2011; 306:76-84. [PMID: 21420785 DOI: 10.1016/j.canlet.2011.02.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 02/18/2011] [Accepted: 02/21/2011] [Indexed: 12/15/2022]
Abstract
Notch signaling has been suggested to be required for many human cancers. However, the role of Notch signaling in human nasopharyngeal carcinoma cells (NPC) remains unknown. Here, we report that Notch-1, Notch-2, Notch-3 and Notch-4 are all detected in NPC cells. Notch inhibitor, GSI, suppresses the levels of Notch-1, Notch-2 and Notch-4, but not Notch-3. In addition, GSI inhibits NPC cell proliferation by inducing the cell cycle arrest and apoptosis. Furthermore, GSI inhibits the AKT and MEK signaling, without affecting P38 and JNK1/2. Thus, NPC cells may up-regulate Notch signaling to maintain cell proliferation and targeting the Notch signaling pathway may offer a potential alternative strategy for the treatment of NPC.
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Affiliation(s)
- Shi-Ming Chen
- Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, China
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12
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Chen YQ, Wang XX, Yao XM, Zhang DL, Yang XF, Tian SF, Wang NS. MicroRNA-195 promotes apoptosis in mouse podocytes via enhanced caspase activity driven by BCL2 insufficiency. Am J Nephrol 2011; 34:549-59. [PMID: 22123611 DOI: 10.1159/000333809] [Citation(s) in RCA: 62] [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] [Received: 06/13/2011] [Accepted: 09/21/2011] [Indexed: 01/04/2023]
Abstract
BACKGROUND The apoptosis of podocytes is a characteristic event in diabetic nephropathy. The aim of this study was to investigate whether microRNAs (miRNAs) affect podocyte apoptosis in diabetic circumstances. METHODS Diabetic nephropathy was induced in DBA/2 mice by intraperitoneal injections of streptozotocin, and the levels of proteinuria were measured with ELISA. Apoptosis-related miRNAs were screened in isolated glomeruli. A conditionally immortalized mouse podocyte cell line was cultured in 25 mMD-glucose and either transfected with miRNA-195 (miR-195) mimics or inhibitors. The levels of BCL2 and caspase expression were determined using real-time RT-PCR and Western blot analysis, respectively. We also measured WT-1 and synaptopodin in podocytes. Apoptosis of podocytes was assessed with Hoechst 33258 nuclear staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry. RESULTS The expression of miR-195 was elevated in both diabetic mice with proteinuria and podocytes that were cultured in high glucose. Transfection with miR-195 reduced the protein levels of BCL2 and contributed to podocyte apoptosis via an increase in caspase-3. miR-195-treated podocytes underwent actin rearrangement and failed to synthesize sufficient levels of WT-1 and synaptopodin proteins, which suggests that the cells had suffered injuries similar to those observed in diabetic nephropathy in both humans and animal models. CONCLUSIONS Taken together, our findings demonstrate that miR-195 promotes apoptosis of podocytes under high-glucose conditions via enhanced caspase cascades for BCL2 insufficiency. This work thus presents a meaningful approach for deciphering mechanisms, by which miRNAs participate in diabetic renal injury.
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Affiliation(s)
- Yu-Qiang Chen
- Department of Nephrology and Rheumatology, Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, China
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Pushechnikov A, Lee MM, Childs-Disney JL, Sobczak K, French JM, Thornton CA, Disney MD. Rational design of ligands targeting triplet repeating transcripts that cause RNA dominant disease: application to myotonic muscular dystrophy type 1 and spinocerebellar ataxia type 3. J Am Chem Soc 2009; 131:9767-79. [PMID: 19552411 PMCID: PMC2731475 DOI: 10.1021/ja9020149] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [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: 12/17/2022]
Abstract
Herein, we describe the design of high affinity ligands that bind expanded rCUG and rCAG repeat RNAs expressed in myotonic dystrophy type 1 (DM1) and spinocerebellar ataxia type 3. These ligands also inhibit, with nanomolar IC(50) values, the formation of RNA-protein complexes that are implicated in both disorders. The expanded rCUG and rCAG repeats form stable RNA hairpins with regularly repeating internal loops in the stem and have deleterious effects on cell function. The ligands that bind the repeats display a derivative of the bisbenzimidazole Hoechst 33258, which was identified by searching known RNA-ligand interactions for ligands that bind the internal loop displayed in these hairpins. A series of 13 modularly assembled ligands with defined valencies and distances between ligand modules was synthesized to target multiple motifs in these RNAs simultaneously. The most avid binder, a pentamer, binds the rCUG repeat hairpin with a K(d) of 13 nM. When compared to a series of related RNAs, the pentamer binds to rCUG repeats with 4.4- to >200-fold specificity. Furthermore, the affinity of binding to rCUG repeats shows incremental gains with increasing valency, while the background binding to genomic DNA is correspondingly reduced. Then, it was determined whether the modularly assembled ligands inhibit the recognition of RNA repeats by Muscleblind-like 1 (MBNL1) protein, the expanded-rCUG binding protein whose sequestration leads to splicing defects in DM1. Among several compounds with nanomolar IC(50) values, the most potent inhibitor is the pentamer, which also inhibits the formation of rCAG repeat-MBNL1 complexes. Comparison of the binding data for the designed synthetic ligands and MBNL1 to repeating RNAs shows that the synthetic ligand is 23-fold higher affinity and more specific to DM1 RNAs than MBNL1. Further studies show that the designed ligands are cell permeable to mouse myoblasts. Thus, cell permeable ligands that bind repetitive RNAs have been designed that exhibit higher affinity and specificity for binding RNA than natural proteins. These studies suggest a general approach to targeting RNA, including those that cause RNA dominant disease.
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Affiliation(s)
- Alexei Pushechnikov
- Department of Chemistry and The Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, The State University of New York, 657 Natural Sciences Complex, Buffalo, NY 14260
| | - Melissa M. Lee
- Department of Chemistry and The Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, The State University of New York, 657 Natural Sciences Complex, Buffalo, NY 14260
| | | | - Krzysztof Sobczak
- Department of Neurology, University of Rochester, Rochester, NY, 14620
| | - Jonathan M. French
- Department of Chemistry and The Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, The State University of New York, 657 Natural Sciences Complex, Buffalo, NY 14260
| | | | - Matthew D. Disney
- Department of Chemistry and The Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, The State University of New York, 657 Natural Sciences Complex, Buffalo, NY 14260
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14
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Abstract
Following earlier reports of radioprotection of cells by Hoechst 33342, we have investigated radioprotection of isolated DNA by the minor groove binders Hoechst 33258 and Hoechst 33342. Analysis of radiation-induced single strand breakage in plasmid DNA (pBR322) showed concentration-dependant protection, up to a dose-modifying factor of 9.3 for 25 microM Hoechst 33258, at which the ligand: bp ratio was 0.67. Since the ligands bind at discrete sites along DNA, sequencing gel analysis was used to investigate the radioprotective effects of the ligands both at and between the ligand-binding sites. These experiments showed that although protection was more pronounced at the binding sites, there was also some reduction in strand-breakage between binding sites. Detailed analysis at a particular site, the EcoR1 site in a 3'-32P-endlabelled 100bp restriction fragment from pBR322, showed that protection was most pronounced at the 'inner T': GAATTC. Irradiation of a synthetic oligodeoxynucleotide containing a single ligand-binding site, and labelled at the 5'-end, gave the expected doublet bands in high resolution gels, corresponding to fragments with 3'-phosphoryl- and 3'-phosphorylglycollate terminii. In the Hoechst 33258-protected sample, the 3'-phosphorylglycollate band was preferentially suppressed within the binding site. These results, together with published crystal structure data for a Hoechst 33258/dodecamer complex, suggest that the site-specific radioprotection may be due to H-atom donation from the benzimidazole NH groups in the ligand to radiation-induced radicals on 4'-deoxyribosyl carbons. In contrast to the experiments with purified DNA, in which the two ligands yielded similar results, Hoechst 33342 was a much more active radioprotector in experiments with intact cells. For 20 microM Hoechst 33342, the dose-modifying factor was 1.7 at 1% survival and 1.3 at 10% survival, whereas the same level of Hoechst 33258 yielded barely detectable protection, perhaps due to a demonstrably lower cellular uptake. Presumably the radioprotection of cells by Hoechst 33342 is due to suppression of DNA strand breakage, and further investigation of the protection mechanism(s) should enable development of improved radioprotectors.
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Affiliation(s)
- L Denison
- Peter MacCallum Cancer Institute, Melbourne, Australia
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15
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Thust R, Rønne M. Structural modifications induced in Chinese hamster V79--E chromosomes by prefixation treatment in vitro with the AT-specific agents netropsin, distamycin A, and Hoechst 33258. Hereditas 2009; 94:209-13. [PMID: 6170606 DOI: 10.1111/j.1601-5223.1981.tb01754.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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16
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Wang GY, Lv QH, Dong Q, Xu RZ, Dong QH. Berbamine induces Fas-mediated apoptosis in human hepatocellular carcinoma HepG2 cells and inhibits its tumor growth in nude mice. J Asian Nat Prod Res 2009; 11:219-228. [PMID: 19408145 DOI: 10.1080/10286020802675076] [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] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Berbamine, a natural compound from the plant Berberis amurensis, is a traditional Chinese medicine mainly used in stimulating normal hematopoiesis in clinic. Our previous studies demonstrated that berbamine has anti-leukemia activity. In this study, we investigated the anticancer activity of berbamine against human hepatocellular carcinoma (HCC) HepG2 cells in vitro and in vivo. Berbamine treatment decreased the cell growth in a dose-dependent manner with an IC(50) value of 34.5 +/- 0.5 microM. Flow cytometric analysis of apoptosis using Annexin V/propidium iodide staining showed that the percentage of apoptotic cells was increased in a time-dependent manner. Berbamine treatment increased the expression level of Fas and P53, caused depolarization of mitochondrial membrane and decrease of membrane potential, and activated caspase-3, -8, and -9 in HepG2 cells. Berbamine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk. HepG2 human HCC xenograft mice treated with berbamine showed a significant reduction in tumor growth rates compared to saline-treated mice. These studies suggest that berbamine exerts anticancer effects on human HCC HepG2 cells in vivo and in vitro, the induction of p53 and the activity of the Fas apoptotic system may participate in the anticancer activity of berbamine in HepG2 cells.
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MESH Headings
- Animals
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/pharmacokinetics
- Antineoplastic Agents, Phytogenic/pharmacology
- Apoptosis/drug effects
- Benzylisoquinolines/chemistry
- Benzylisoquinolines/pharmacokinetics
- Benzylisoquinolines/pharmacology
- Berberine/chemistry
- Bisbenzimidazole/pharmacology
- Carcinoma, Hepatocellular/drug therapy
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- Humans
- Medicine, Chinese Traditional
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Plants, Medicinal/chemistry
- Time Factors
- Tumor Suppressor Protein p53/metabolism
- Xenograft Model Antitumor Assays
- fas Receptor/metabolism
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Affiliation(s)
- Guan-Yu Wang
- Department of Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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17
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Rønne M. Fluorouracil synchronization of human lymphocyte cultures. Induction of high resolution R-banding by simultaneous in vitro exposure to 5-bromodeoxyuridine/Hoechst 33258. Hereditas 2008; 101:205-8. [PMID: 6083993 DOI: 10.1111/j.1601-5223.1984.tb00916.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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18
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Liu Y, Xing H, Han X, Shi X, Liang F, Cheng G, Lu Y, Ma D. Apoptosis of HeLa cells induced by cisplatin and its mechanism. ACTA ACUST UNITED AC 2008; 28:197-9. [PMID: 18480997 DOI: 10.1007/s11596-008-0221-7] [Citation(s) in RCA: 18] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2007] [Indexed: 12/17/2022]
Abstract
To study the apoptosis induced by cisplatin in cervical cancer cell line HeLa and its mechanism, cell growth inhibition of cisplatin on HeLa cells was analyzed by MTT assay. Cell apoptosis was examined by cytometry and Hoechst33258 staining after treatment with cisplatin. The effects of cisplatin on transcription of E6 were analyzed by RT-PCR. The protein expressions of E6, p53, p21, Bax and Bcl-2 were studied by Western blotting. Cisplatin inhibited proliferation in a time-and dose-dependant manner. Cytometically, sub-G(1) peak showed higher apoptosis rates in the experimental group than those in the control. Hoechst33258staining exhibited apoptosis induced by cisplatin. RT-PCR revealed that cisplatin decreased transcription of E6. Western blotting showed that cisplatin decreased protein expression of E6 and increased protein expression of p53, p21 and Bax. It had no effect on protein expression of Bcl-2. It is concluded that cisplatin can induce apoptosis in HeLa cells by suppressing HPV E6 and thereby restoring the function of p53.
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Affiliation(s)
- Youqing Liu
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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19
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20
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Abstract
The experimental approach to revealing the genetic information hidden in kinetoplastid cryptogenes and expressed through the posttranscriptional mRNA processing of U-insertion/deletion editing proceeds in reverse to the informational flow of the RNA editing process itself. While the editing integrates the informational content of maxicircle-encoded cryptogenes with that of minicircle-encoded gRNAs to produce functional edited mRNAs, the cryptogene analysis utilizes a comparison of the mature mRNA sequence with the cryptogene sequence to deduce the locations of edited sites and editing patterns, and a comparison of that mRNA sequence with the minicircle (or minicircle equivalent) sequences to identify the corresponding guide RNAs. Although a "direct" approach (prediction of a fully edited sequence pattern based on the analysis of cryptogene and minicircle sequences) seems to be theoretically possible, it proved to be not practically feasible. The major steps of the procedures utilized to decipher editing in a broad range of kinetoplastid species are presented in this chapter.
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Affiliation(s)
- Dmitri A Maslov
- Department of Biology, University of California, Riverside, California, USA
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21
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Tawar U, Bansal S, Shrimal S, Singh M, Tandon V. Nuclear condensation and free radical scavenging: a dual mechanism of bisbenzimidazoles to modulate radiation damage to DNA. Mol Cell Biochem 2007; 305:221-33. [PMID: 17619948 DOI: 10.1007/s11010-007-9546-y] [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] [Received: 04/05/2007] [Accepted: 06/21/2007] [Indexed: 10/23/2022]
Abstract
The complexing of histones with DNA and the resulting condensation of chromatin protects mammalian cell, from radiation-induced strand breakage. In the present study, benzimidazoles DMA and TBZ showed marked radioprotection through drug-induced compaction of chromatin and direct quenching of free radicals generated by radiation. The mammalian cells were incubated with 100 microM concentration of DMA and TBZ and irradiated at 5 Gy; both the ligands showed nuclei condensation suggesting a probable mechanism to protect DNA from radiation damage. The bisubstituted analogs of Hoechst 33342 are found to be better free radical scavengers and protect DNA against radiation-induced damage at a lower concentration than the parent molecule. Both the ligands also quenched free radicals in isolated free radical system suggesting their dual mode of action against radiation-induced damage to DNA. Molecules binding to the chromatin alter gene expression, whereas in this study both the ligands have not shown any profound effect on the nucleosome assembly and gene expression in vitro and in vivo. Both ligands afford a 2-fold protection by altering DNA structure as well as through direct free radical quenching in bulk solution in comparison to the parent ligand, which acts only through quenching of free radicals.
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Affiliation(s)
- Urmila Tawar
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, 110007, India
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22
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Saiko P, Horvath Z, Murias M, Handler N, Jaeger W, Erker T, Fritzer-Szekeres M, Szekeres T. Antitumor effects of 3,3',4,4',5,5'-hexahydroxystilbene in HL-60 human promyelocytic leukemia cells. Nucleosides Nucleotides Nucleic Acids 2007; 25:1013-7. [PMID: 17065056 DOI: 10.1080/15257770600890624] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Resveratrol (3,4',5-trihydroxystilbene, RV) exerts remarkable cytostatic and cytotoxic effects against a multitude of human cancer cell lines. Since the introduction of additional hydroxyl groups was supposed to increase the biological activity of RV, we have synthesized a number of polyhydroxylated stilbene analogues as potential antitumor agents. In this study, the activity of 3,3',4,4',5,5'-hexahydroxystilbene (M8) was investigated in HL-60 human promyelocytic leukemia cells. Employing a growth inhibition assay, incubation with M8 and RV resulted in IC50 values of 6.25 and 12 microM, respectively. Using a specific Hoechst/propidium iodide double staining method, we found that M8 was able to induce apoptosis in concentrations significantly lower than those of RV. In addition, M8 arrested cells in the S phase and totally depleted cells in the G2-M phase of the cell cycle (143% and 0% of control after treatment with 12.5 microM M8, respectively). We therefore believe that this promising agent deserves further preclinical and in vivo testing.
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Affiliation(s)
- P Saiko
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, General Hospital of Vienna, Medical University of Vienna, Vienna, Austria.
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23
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Khan QA, Pilch DS. Topoisomerase I-mediated DNA cleavage induced by the minor groove-directed binding of bibenzimidazoles to a distal site. J Mol Biol 2007; 365:561-9. [PMID: 17095016 PMCID: PMC1849979 DOI: 10.1016/j.jmb.2006.10.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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: 05/02/2006] [Revised: 09/13/2006] [Accepted: 10/09/2006] [Indexed: 10/23/2022]
Abstract
Many agents (e.g. camptothecins, indolocarbazoles, indenoisoquinolines, and dibenzonaphthyridines) stimulate topoisomerase I (TOP1)-mediated DNA cleavage (a behavior termed topoisomerase I poisoning) by interacting with both the DNA and the enzyme at the site of cleavage (typically by intercalation between the -1 and +1 base-pairs). The bibenzimidazoles, which include Hoechst 33258 and 33342, are a family of DNA minor groove-directed agents that also stimulate topoisomerase I-mediated DNA cleavage. However, the molecular mechanism by which these ligands poison TOP1 is poorly understood. Toward this goal, we have used a combination of mutational, footprinting, and DNA binding affinity analyses to define the DNA binding site for Hoechst 33258 and a related derivative that results in optimal induction of TOP1-mediated DNA cleavage. We show that this DNA binding site is located downstream from the site of DNA cleavage, encompassing the base-pairs from position +4 to +8. The distal nature of this binding site relative to the site of DNA cleavage suggests that minor groove-directed agents like the bibenzimidazoles poison TOP1 via a mechanism distinct from compounds like the camptothecins, which interact at the site of cleavage.
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Affiliation(s)
- Qasim A. Khan
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854-5635
| | - Daniel S. Pilch
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854-5635
- The Cancer Institute of New Jersey, New Brunswick, NJ 08901
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24
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Wang YH, Chiu WT, Wang YK, Wu CC, Chen TL, Teng CF, Chang WT, Chang HC, Tang MJ. Deregulation of AP-1 proteins in collagen gel-induced epithelial cell apoptosis mediated by low substratum rigidity. J Biol Chem 2006; 282:752-63. [PMID: 17085440 DOI: 10.1074/jbc.m604801200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [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: 11/06/2022] Open
Abstract
In this study, we established that collagen gel, but not collagen gel coating, induced apoptosis exclusively in epithelial cell lines, which indicated that low substratum rigidity might trigger cell apoptosis. To confirm this, we used collagen gels with different rigidities due to cross-linking or physical disruption of collagen fibrils caused by sonication. We found that collagen gel-induced apoptosis was inversely correlated with substratum rigidity. Low substratum rigidity collagen gel-induced apoptosis was neither prevented by Bcl-2 overexpression nor preceded by mitochondrial release of cytochrome c. This suggested that the mitochondrial pathway was not involved in low substratum rigidity-induced apoptosis. Low substratum rigidity activated c-Jun N-terminal kinase (JNK) within 4 h, but it also rapidly down-regulated c-Jun within 1 h and triggered persistent aberrant expression of c-Fos for at least 24 h. Either reduced c-Jun expression or c-Fos overexpression induced apoptosis in several epithelial cells. Inhibiting low substratum rigidity-induced JNK activation prevented aberrant c-Fos expression but only partially blocked low substratum rigidity-induced apoptosis. Taking these results together, we conclude that low substratum rigidity collagen gel induced apoptosis in epithelial cells and that deregulated AP-1 proteins mediated that apoptosis, at least in part.
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Affiliation(s)
- Yao-Hsien Wang
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
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25
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Abstract
DjB1 (Hsp40/DnajB1/Hdj1) is a member of the Hsp40/DnaJ family that functions as a co-chaperone of mammalian Hsp70s. DjB1 recognizes substrate proteins and facilitates the ATPase activity of Hsp70. We generated DjB1 deficient mice. The DjB1(-/-) mice were viable and fertile with no obvious abnormalities, thus indicating that DjB1 is dispensable for development and viability. No difference was found between the DjB1(-/-) and wild-type peritoneal macrophages regarding resistance against various types of apoptosis-inducing reagents. However, DjB1(-/-) cells showed decreased thermotolerance in the early phase after mild heat treatment, but not in the late phase. After the heat treatment, Hsp70 was induced similarly in wild-type and DjB1(-/-) cells. Immunofluorescence staining of wild-type cells revealed the accumulation of DjB1 and Hsc70 in the nucleus after heat treatment. DjB1 also accumulated in the centrosome. The accumulation of Hsc70 in the nucleus was also observed in DjB1(-/-) cells. These results suggest that the impaired thermotolerance of DjB1(-/-) cells is not due to a mislocation of the Hsp70 family.
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Affiliation(s)
- Yukako Uchiyama
- Department of Molecular Genetics, Graduate School of Medical Sciences, Kumamoto University, Honjo 1-1-1, Kumamoto 860-8556
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26
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Correa BJ, Canzio D, Kahane AL, Reddy PM, Bruice TC. DNA sequence recognition by Hoechst 33258 conjugates of hairpin pyrrole/imidazole polyamides. Bioorg Med Chem Lett 2006; 16:3745-50. [PMID: 16682192 DOI: 10.1016/j.bmcl.2006.04.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 03/07/2006] [Accepted: 04/19/2006] [Indexed: 11/20/2022]
Abstract
A series of hairpin pyrrole/imidazole polyamides linked to a Hoechst 33258 (Ht) analogue (5-7) were synthesized on solid-phase by adopting an Fmoc technique using a series of PyBOP/HOBt mediated coupling reactions. The dsDNA binding properties of Ht-polyamides 5-7 were determined by thermal denaturation experiments. Hairpin Ht-polyamides 5-7 bound to dsDNA sequences 16 and 18 show DeltaTm values that are 14-18 degrees higher than linear Ht-polyamides bound to the same sequences. All three Ht-polyamides were found to be selective for their 9-bp match dsDNA sequences, supporting a relative stronger interaction of an Im/Py anti-parallel dimer with an appropriately positioned G/Cbp rather than sequences containing only A/Tbps. In addition, Ht-polyamides 5 and 7 showed a 20-fold preference for a properly placed G/Cbp over a C/Gbp, while 6 showed a 10-fold preference.
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Affiliation(s)
- Bryan J Correa
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106, USA
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27
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Karagiannis TC, Lobachevsky PN, Martin RF. DNA targeted UVA photosensitization: characterization of an extremely photopotent iodinated minor groove binding DNA ligand. J Photochem Photobiol B 2006; 83:195-204. [PMID: 16488619 DOI: 10.1016/j.jphotobiol.2005.12.013] [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] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Revised: 12/15/2005] [Accepted: 12/15/2005] [Indexed: 11/29/2022]
Abstract
Previous studies have described UVA-induced DNA strand breakage at the binding sites of iodinated DNA minor groove binding bisbenzimidazoles. The DNA breakage, presumably mediated by the carbon-centred ligand radical produced by photodehalogenation, was also shown to be cytotoxic. The earlier studies included a comparison of three ligand isomers, designated ortho-, meta- and para-iodoHoechst, and the efficiency of photo-induction of strand breaks in plasmid DNA proved to be much higher for the ortho-isomer. We have now extended the comparison of the three isomers with respect to photo-induced cytotoxicity in K562 cells. Although the relationship between the extent of nuclear uptake and the concentration of the ligand in the medium was similar for the three isomers, assay of in situ dehalogenation in drug-treated cells indicated that the apparent cross-section for dehalogenation of the ortho-isomer was greater than 5-fold higher than that for the meta- and para-isomers. Also, analysis of clonogenic survival data showed that the dehalogenation event associated with ortho-iodoHoechst was a more efficient mediator of UVA-induced cytotoxicity in K562 cells than that for meta- or para-iodoHoechst. The number of dehalogenation events associated with 50% cell-kill for ortho-iodoHoechst (1.23+/-0.04 x 10(4)) was less than that for the para- (3.92+/-0.29 x 10(4)) and meta- (11.6+/-0.90 x 10(4)) isomers. Thus it is concluded that the photopotency of ortho-iodoHoechst, which is an important feature in the context of its potential use in clinical phototherapy, is due not only to more efficient UVA-mediated dehalogenation of the ligand, but also to greater cytotoxic potency per dehalogenation event.
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Affiliation(s)
- Tom C Karagiannis
- Trescowthick Research Laboratories, Peter MacCallum Cancer Centre, Molecular Radiation Biology Laboratory, Locked Bag No. 1, A'Beckett Street, Melbourne, Vic. 8086, Australia
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28
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Sun CK, Zhang XY, Sheard PW, Mabuchi A, Wheatley AM. Change in mitochondrial membrane potential is the key mechanism in early warm hepatic ischemia-reperfusion injury. Microvasc Res 2006; 70:102-10. [PMID: 15893342 DOI: 10.1016/j.mvr.2005.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [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: 12/08/2004] [Revised: 03/18/2005] [Accepted: 04/02/2005] [Indexed: 10/25/2022]
Abstract
The mitochondrion has been proposed to be both a target and a perpetuator of hepatic ischemia-reperfusion (IR) injury because of its reactive oxygen species (ROS) formation. Our hypothesis is that subcellular derangement in mitochondrial function is one of the earliest steps leading to the early IR-mediated loss of hepatocellular integrity. Under chloralhydrate anesthesia (36 mg/kg BW), Sprague-Dawley rats (n=7) were subjected to 40 min of warm hepatic lobular ischemia followed by 60 min reperfusion. Rats (n=7) without hepatic IR were used as controls. The fluorochromes rhodamine 123 and bisbenzimide were administered intravenously for observation of changes in mitochondrial membrane potential and hepatocellular viability, respectively. Intravital fluorescence microscopy (IVFM) was performed prior to ischemia and at 15, 45, and 60 min after reperfusion in the experimental group and at corresponding time points in the control group. A parallel relationship between mitochondrial membrane potential and cell viability as reflected in a concomitant reduction in nuclear and cytoplasmic fluorescence intensity during IR was demonstrated (r2=0.76, P<0.05). The diminution in fluorescence intensities also correlated significantly with the elevation in plasma transaminase activities (r2>0.90, P<0.05). Our data suggested that alteration in mitochondrial membrane potential is a critical subcellular event leading to hepatocellular damage in the early phase of hepatic IR injury.
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Affiliation(s)
- Cheuk-Kwan Sun
- Microcirculation Research Laboratory, Department of Physiology, School of Medical Sciences, University of Otago, PO Box 913, Dunedin, New Zealand
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29
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Jean-Moreno V, Rojas R, Goyeneche D, Coombs GH, Walker J. Leishmania donovani: Differential activities of classical topoisomerase inhibitors and antileishmanials against parasite and host cells at the level of DNA topoisomerase I and in cytotoxicity assays. Exp Parasitol 2006; 112:21-30. [PMID: 16293247 DOI: 10.1016/j.exppara.2005.08.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [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: 06/08/2005] [Revised: 08/30/2005] [Accepted: 08/31/2005] [Indexed: 11/23/2022]
Abstract
Different classes of topoisomerase (TOP) inhibitors and antitrypanosomatid agents exhibited variable efficacies against Leishmania donovani parasites and human mononuclear cells both at the level of DNA topoisomerase I (TOPI) catalytic activity and in cytotoxicity assays. Bis-benzimidazoles and the diamidine diminazene aceturate exhibited uniformly high efficacies against parasite and host enzymes as well as against parasite and mononuclear cells, but pentamidine showed around 2 orders of magnitude greater specificity for Leishmania TOPI and amastigote cells (P<0.05). The protoberberine coralyne and the flavonoid quercetin were highly potent, but non-selective, inhibitors in vitro, although the latter showed slight selectivity for parasite TOPI. Camptothecin was selective for mononuclear cells at both levels (P<0.05) and sodium stibogluconate was selective only at the enzyme level displaying 30-fold greater potency against parasite TOPI (P<0.05). These data suggest that at least part of pentamidines' leishmanicidal activity may be mediated through TOPI inhibition, and support the feasibility of exploiting differences between Leishmania and human TOPs to develop modified compounds with improved selectivity.
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Affiliation(s)
- Valerie Jean-Moreno
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Biochemistry and Molecular Biology Unit, Avenida 1 Norte No. 3-03, AA 5390, Cali, Valle de Cauca, Colombia
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Habermeyer M, Fritz J, Barthelmes HU, Christensen MO, Larsen MK, Boege F, Marko D. Anthocyanidins modulate the activity of human DNA topoisomerases I and II and affect cellular DNA integrity. Chem Res Toxicol 2005; 18:1395-404. [PMID: 16167831 DOI: 10.1021/tx050039n] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [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: 11/29/2022]
Abstract
In the present study, we investigated the effect of anthocyanidins on human topoisomerases I and II and its relevance for DNA integrity within human cells. Anthocyanidins bearing vicinal hydroxy groups at the B-ring (delphinidin, DEL; cyanidin, CY) were found to potently inhibit the catalytic activity of human topoisomerases I and II, without discriminating between the IIalpha and the IIbeta isoforms. However, in contrast to topoisomerase poisons, DEL and CY did not stabilize the covalent DNA-topoisomerase intermediates (cleavable complex) of topoisomerase I or II. Using recombinant topoisomerase I, the presence of CY or DEL (> or = 1 microM) effectively prohibited the stabilization of the cleavable complex by the topoisomerase I poison camptothecin. We furthermore investigated whether the potential protective effect vs topoisomerase I poisons is reflected also on the cellular level, affecting the DNA damaging properties of camptothecin. Indeed, in HT29 cells, low micromolar concentrations of DEL (1-10 microM) significantly diminished the DNA strand breaking effect of camptothecin (100 microM). However, at concentrations > or = 50 microM, all anthocyanidins tested (delphinidin, cyanidin, malvidin, pelargonidin, and paeonidin), including those not interfering with topoisomerases, were found to induce DNA strand breaks in the comet assay. All of these analogues were able to compete with ethidium bromide for the intercalation into calf thymus DNA and to replace the minor groove binder Hoechst 33258. These data indicate substantial affinity to double-stranded DNA, which might contribute at least to the DNA strand breaking effect of anthocyanidins at higher concentrations (> or = 50 microM).
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Affiliation(s)
- Michael Habermeyer
- Department of Chemistry, Division of Food Chemistry and Environmental Toxicology, University of Kaiserslautern, Erwin-Schroedinger Strasse 52, 67663 Kaiserslautern, Germany
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Nomura T, Yamasaki M, Nomura Y, Mimata H. Expression of the inhibitors of apoptosis proteins in cisplatin-resistant prostate cancer cells. Oncol Rep 2005; 14:993-7. [PMID: 16142363] [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: 05/04/2023] Open
Abstract
Acquired multi-drug resistance remains a major obstacle in the management of prostate cancer. The objective of this study was to examine whether chemoresistance could be due in part to the expression of the inhibitors of apoptosis proteins (IAPs). We established cisplatin-resistant LNCaP sublines. We examined the effects of cisplatin on cell growth and apoptosis in LNCaP cells and LNCaP sublines by 2-(4-lodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-1) assay and Hoechst 33258 staining, and analyzed cross-resistance to adriamycin, 5-fluorouracil, taxol, taxotere, and etoposide. In addition, the expression of IAP-1, IAP-2, X-linked IAP (XIAP), neuronal apoptosis inhibitory protein, and survivin was investigated by immunoblot analysis in LNCaP sublines. Although the growth rates were reduced in a dose-dependent manner by cisplatin in LNCaP sublines, the anti-proliferative effects of cisplatin were significantly decreased in LNCaP sublines compared to LNCaP cells. Cisplatin-resistant sublines, LNCaP/C1, LNCaP/ C2, and LNCaP/C3 cells, were 6.3-, 9.1-, and 22.3-fold more resistant to cisplatin than LNCaP cells, respectively, and this resistance was paralleled with reduced induction of apoptosis. LNCaP/C3 cells showed cross-resistance to adriamycin, 5-fluorouracil, and etoposide whereas those cells exhibited no or only weak cross-resistance against taxol and taxotere. With the exception of survivin, all the IAPs were identified in LNCaP cells by immunoblot analysis. Interestingly, the expression of IAP-2, XIAP, and survivin gradually increased with the extent of cisplatin-resistance. Altered expression of IAP-2, XIAP, and survivin was involved in these phenotypes of cisplatin-resistant LNCaP sublines. IAPs may make an important contribution to the resistance to the apoptotic effect of cisplatin in prostate cancer.
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Affiliation(s)
- Takeo Nomura
- Department of Oncological Science (Urology), Oita University Faculty of Medicine, Oita, Japan.
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Abstract
We report for the first time that saliva of the hard tick and Lyme disease vector, Ixodes scapularis, is a potent inhibitor of angiogenesis. Saliva (< or = 1:500 dilutions) or salivary gland (0.1-0.5 pairs/assay) dose-dependently inhibits microvascular endothelial cell (MVEC) proliferation. Inhibition was also detected with the saliva of the cattle tick Boophilus microplus but not with the salivary gland of Anopheles gambiae, An. stephensi, Lutzomyia longipalpis, Phlebotomus papatasi, Aedes aegypti, Culex quinquefasciatus, and Cimex lectularius. Inhibition of MVEC proliferation by I. Scapularis saliva was accompanied by a change in cell shape (shrinkage of the cytoplasm with loss of cell-cell interactions) and apoptosis which was estimated by expression of phosphatidylserine using the Apopercentage dye, and by a typical pattern of chromatin margination, condensation, and fragmentation as revealed by nuclear staining with Hoechst 33258. The effect of saliva appears to be mediated by endothelial cell alpha5beta1 integrin, because monoclonal antibodies against this but not alphavbeta3, alphavbeta5, alpha9beta1, or alpha2beta1 integrins remarkably block its effect. In addition, SDS/PAGE shows that saliva specifically degrades purified alpha5beta1 but not alphavbeta5 or alphavbeta3 integrins. Incubation of saliva with EDTA and 1,10-phenanthroline, but not phenylmethylsulfonyl fluoride (PMSF), inhibits saliva-dependent degradation of purified alpha5beta1 integrin, suggesting that a metalloprotease is responsible for the activity. Finally, saliva at < or = 1:1,000 dilutions blocks sprouting formation from chick embryo aorta implanted in Matrigel, an in vitro model of angiogenesis. These findings introduce the concept that tick saliva is a negative modulator of angiogenesis-dependent wound healing and tissue repair, therefore allowing ticks to feed for days. Inhibition of angiogenesis was hitherto an unidentified biologic property of the saliva of any blood-sucking arthropod studied so far. Its presence in tick saliva may be regarded as an additional source of angiogenesis inhibitors with potential applications for the study of both vector and vascular biology.
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Affiliation(s)
- Ivo M B Francischetti
- Vector Biology Section, LMVR, NIAID, NIH, 12735 Twinbrook Parkway (Twinbrook III), Room 2E28, Rockville, MD 20892-8132, USA.
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Abstract
We report for the first time that saliva of the hard tick and Lyme disease vector, Ixodes scapularis, is a potent inhibitor of angiogenesis. Saliva (< or = 1:500 dilutions) or salivary gland (0.1-0.5 pairs/assay) dose-dependently inhibits microvascular endothelial cell (MVEC) proliferation. Inhibition was also detected with the saliva of the cattle tick Boophilus microplus but not with the salivary gland of Anopheles gambiae, An. stephensi, Lutzomyia longipalpis, Phlebotomus papatasi, Aedes aegypti, Culex quinquefasciatus, and Cimex lectularius. Inhibition of MVEC proliferation by I. Scapularis saliva was accompanied by a change in cell shape (shrinkage of the cytoplasm with loss of cell-cell interactions) and apoptosis which was estimated by expression of phosphatidylserine using the Apopercentage dye, and by a typical pattern of chromatin margination, condensation, and fragmentation as revealed by nuclear staining with Hoechst 33258. The effect of saliva appears to be mediated by endothelial cell alpha5beta1 integrin, because monoclonal antibodies against this but not alphavbeta3, alphavbeta5, alpha9beta1, or alpha2beta1 integrins remarkably block its effect. In addition, SDS/PAGE shows that saliva specifically degrades purified alpha5beta1 but not alphavbeta5 or alphavbeta3 integrins. Incubation of saliva with EDTA and 1,10-phenanthroline, but not phenylmethylsulfonyl fluoride (PMSF), inhibits saliva-dependent degradation of purified alpha5beta1 integrin, suggesting that a metalloprotease is responsible for the activity. Finally, saliva at < or = 1:1,000 dilutions blocks sprouting formation from chick embryo aorta implanted in Matrigel, an in vitro model of angiogenesis. These findings introduce the concept that tick saliva is a negative modulator of angiogenesis-dependent wound healing and tissue repair, therefore allowing ticks to feed for days. Inhibition of angiogenesis was hitherto an unidentified biologic property of the saliva of any blood-sucking arthropod studied so far. Its presence in tick saliva may be regarded as an additional source of angiogenesis inhibitors with potential applications for the study of both vector and vascular biology.
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Affiliation(s)
- Ivo M B Francischetti
- Vector Biology Section, LMVR, NIAID, NIH, 12735 Twinbrook Parkway (Twinbrook III), Room 2E28, Rockville, MD 20892-8132, USA.
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Disney MD, Stephenson R, Wright TW, Haidaris CG, Turner DH, Gigliotti F. Activity of Hoechst 33258 against Pneumocystis carinii f. sp. muris, Candida albicans, and Candida dubliniensis. Antimicrob Agents Chemother 2005; 49:1326-30. [PMID: 15793106 PMCID: PMC1068638 DOI: 10.1128/aac.49.4.1326-1330.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 11/20/2022] Open
Abstract
Hoechst 33258 is a compound that binds nucleic acids. We report that Hoechst 33258 exhibits antimicrobial activity against Pneumocystis carinii f. sp. muris in a mouse model for P. carinii pneumonia and against Candida albicans and Candida dubliniensis in vitro. Relative to saline treatment, a 14-day, daily treatment of mice with 37.5 mg of Hoechst 33258/kg of body weight after inoculation with P. carinii reduced by about 100-fold the number of P. carinii organisms detected by either PCR or by microscopy after silver staining. For comparison, treatment based on a dose of 15 to 20 mg of the trimethoprim component in trimethoprim-sulfamethoxazole/kg reduced the number of P. carinii by about fourfold. In vitro inhibition of P. carinii group I intron splicing was observed with a 50% inhibitory concentration (IC50) of 30 microM in 2 or 4 mM Mg2+, suggesting RNA as a possible target. However, Hoechst 33258 inhibits growth of Candida strains with and without group I introns. IC50s ranged from 1 to 9 microM for strains with group I introns and were 12 and 32 microM for two strains without group I introns. These studies demonstrate that compounds that bind fungal nucleic acids have the potential to be developed as new therapeutics for Pneumocystis and possibly other fungi, especially if they could be directed to structures that are not present in mammalian cells, such as self-splicing introns.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA
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Abstract
Fungal pathogens are increasing in prevalence due to an increase in resistant strains and the number of immunocompromised humans. Candida albicans is one of these pathogens, and approximately 40% of strains contain a group I self-splicing intron, which is a potential RNA drug target, in their large subunit rRNA precursor. Here, we report that Hoechst 33258 and derivatives thereof are selective inhibitors of C. albicans group I intron self-splicing with an IC50 of 17 microM in 2 mM Mg2+. Chemical probing of the intron in the presence of Hoechst 33258 reveals that the folding of several nucleotides in the P4/P6 region of the intron is affected. A nucleotide near the J4/5 region is protected from chemical modification in the presence of Hoechst 33258 and several nearby are more reactive; this suggests that this region is the molecule's binding site. These results expand the available information on small-molecule targeting of RNA and suggest that the RNA-targeting scaffold provided by Hoechst may prove valuable in designing compounds that inhibit the functions of RNA.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, University of Rochester, Rochester, NY 14627-0216, USA
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Liu JJ, Huang RW, Lin DJ, Wu XY, Lin Q, Peng J, Pan X, Song YQ, Zhang MH, Hou M, Chen F. Antiproliferation effects of ponicidin on human myeloid leukemia cells in vitro. Oncol Rep 2005; 13:653-7. [PMID: 15756438] [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: 05/02/2023] Open
Abstract
Ponicidin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. Ponicidin has been reported to have anti-tumor effects on a large variety of malignant diseases. In this study, we investigated the anti-proliferation effects of ponicidin on human myeloid K562 and HL-60 cells. Cell viability was measured by MTT assay; cell apoptosis was assessed by flow cytometry, DNA fragmentation analysis and Hoechst 33258 staining. Caspase-3 and poly(ADP-ribose) polymerase (PARP) activation and Bax and Bcl-2 expression were detected by Western blot analysis. The results revealed that ponicidin could significantly inhibit the growth of K562 and HL-60 cells by induction of apoptosis. The suppression was both time- and dose-dependent. Cell apoptosis was observed clearly after the cells were treated with ponicidin for 48-72 h. Western blotting showed cleavage of the caspase-3 zymogen protein (32 kDa) with the appearance of its 17 kDa subunit, together with a cleaved 89-kDa fragment of 116 kDa PARP when apoptosis occurred. Bcl-2 expression was down-regulated while Bax expression up-regulated concurrently when the cells were treated with ponicidin for 24-48 h. Therefore, we conclude that ponicidin has significant anti-proliferation effects by induction of apoptosis on myeloid leukemia cells in vitro, down-regulation of Bcl-2, and up-regulation of Bax, and that activation of caspase-3 and PARP may be an important apoptosis-inducing mechanism. The results suggest that ponicidin may serve as a potential therapeutic agent for leukemia.
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Affiliation(s)
- Jia-Jun Liu
- Sun Yat-sen University, Department of Haematology and Oncology, The Third Affiliated Hospital of Sun Yat-sen University, Tian-He Road 600, Guangzhou, Guangdong 510630, PR China.
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Takashima T, Fujiwara Y, Hamaguchi M, Sasaki E, Tominaga K, Watanabe T, Oshitani N, Higuchi K, Arakawa T. Relationship between peroxisome proliferator-activated receptor-gamma expression and differentiation of human esophageal squamous cell carcinoma. Oncol Rep 2005; 13:601-6. [PMID: 15756430] [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: 05/02/2023] Open
Abstract
Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, is involved in suppressing the growth of several tumors. We showed that PPAR-gamma is expressed in Barrett's adenocarcinoma cell lines and inhibited the growth of these lines through the induction of G1 cell cycle arrest and apoptosis. We examined PPAR-gamma expression in human esophageal squamous cell carcinoma (SCC) in vitro and in vivo and investigated whether PPAR-gamma ligands affect the proliferation and apoptosis of human SCC cell lines. Biopsy specimens (n=46) obtained from human SCC of the esophagus were stained using a monoclonal antibody against human PPAR-gamma. We assessed the effects of PPAR-gamma ligands on the growth of SCC cells by adding 15-deoxy prostaglandin J2 (15d-PGJ2), or troglitazone to six human esophageal SCC cell lines (TE-1, TE-2, TE-3, TE-5, TE-8, and TE-9). Immunohistochemical staining showed that 34 of 46 (73.9%) SCC of the esophagus expressed PPAR-gamma. All SCC cell lines expressed PPAR-gamma mRNA and protein, especially when poorly differentiated (TE-2, TE-5, and TE-9). The PPAR-gamma ligands significantly and dose-dependently inhibited the proliferation of SCC lines, except for well-differentiated TE-1 and TE-3. Apoptosis was induced by 15d-PGJ2 (10 microM) in all tested SCC lines except TE-1, whereas troglitazone (50 microM) was marginally effective in only the TE-2 and TE-3 cell lines. The present findings suggest that PPAR-gamma could be a therapeutic target for treating squamous cell carcinoma of the esophagus, possibly through the induction of apoptosis.
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Affiliation(s)
- Takashi Takashima
- Department of Gastroenterology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan. d98m011@ med.osaka-cu.ac.jp
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Wang X, Tang X, Li M, Marshall J, Mao Z. Regulation of neuroprotective activity of myocyte-enhancer factor 2 by cAMP-protein kinase A signaling pathway in neuronal survival. J Biol Chem 2005; 280:16705-13. [PMID: 15735306 DOI: 10.1074/jbc.m501819200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [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: 11/06/2022] Open
Abstract
The transcription factor myocyte-enhancer factor 2 (MEF2) has been shown to be required for the survival of different types of neurons. However, the death- or survival-inducing second messenger pathways that regulate MEF2 activity remain to be fully elucidated. Membrane depolarization by KCl induces neuronal survival that is dependent upon MEF2-mediated gene transactivation. Here we report that membrane depolarizationinduced activation of MEF2 requires the cAMP-protein kinase A (PKA) pathway. Inhibition of the activity of cAMP-PKA pathway attenuates membrane depolarization-induced activation of MEF2 activity and neuronal survival, whereas enhancing the activity of this pathway prevents KCl withdrawal-induced inhibition of MEF2 and neuronal apoptosis. Moreover, PKA directly phosphorylates MEF2 at Thr-20 in vitro to increase MEF2 DNA binding activity. A mutation of Thr-20 to Ala renders MEF2 resistant to PKA phosphorylation in vitro and reduces its DNA binding activity. Transfection of this T20A mutant blocks survival and induces apoptosis in cultured cortical and cerebellar granule neurons. This study identifies the transcription factor MEF2 as a target of cAMP-PKA pathway and demonstrates that PKA phosphorylation of MEF2 is a key step in modulating its DNA binding activity and ability to promote neuronal survival.
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Affiliation(s)
- Xuemin Wang
- Department of Medicine, Brown University Medical School and Rhode Island Hospital, Providence, Rhode Island 02903, USA
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Saiko P, Bauer W, Horvath Z, Hoechtl T, Grusch M, Illmer C, Madlener S, Krupitza G, Mader RM, Schott H, Fritzer-Szekeres M, Szekeres T. Cytotoxic and apoptotic effects of novel heterodinucleoside phosphates consisting of 5-fluorodeoxyuridine and Ara-C in human cancer cell lines. Nucleosides Nucleotides Nucleic Acids 2005; 23:1507-11. [PMID: 15571287 DOI: 10.1081/ncn-200027723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In search for possible alternatives in the treatment of human malignancies we investigated several new heterodinucleoside phosphates consisting of 5-Fluorodeoxyuridine (5-FdUrd) and Arabinofuranosylcytosine (Ara-C). We show that all dimers tested inhibited the number of colonies of CCL228, CCL227, 5-FU resistant CCL227 and HT-29 human colon tumor cells with IC50 values ranging from 0.65 to 1 nM. Dimer # 2 inhibited the number of sensitive and Ara-C resistant H9 human lymphoma cells with IC50 values ranging from 200 to 230 nM. Since no significant difference in the cytotoxicity of the dimers could be observed between sensitive and resistant cells, these compounds might be used in the treatment of 5-FU and Ara-C resistant tumors.
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Affiliation(s)
- P Saiko
- Clinical Institute of Med. and Chem. Laboratory Diagnostics, University of Vienna, Vienna, Austria
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Abstract
Despite numerous experimental and clinical investigations, there is no unifying concept on pathophysiology and pathogenesis of chronic pancreatitis. Defining the interplay between pancreatic microcirculation and parenchymal tissue, we will provide a basis for the better understanding of pancreatic fibrogenesis using in vivo high-resolution multifluorescence microscopy in dibutyltin chloride (DBTC)-exposed rats. Pancreatic microcirculation at days 3 and 7 after DBTC revealed leukocyte activation with a two-fold higher fraction of rolling cells and a nine- to 10-fold increase of cells firmly adherent to the endothelial lining, followed by subsequent transendothelial migration into tissue, as given by chloracetate esterase histology. In vivo staining of acinar tissue with bisbenzimide presented single cells exhibiting nuclear chromatin condensation and fragmentation. Apoptotic cell death was confirmed by immunohistochemical staining for active caspase-3 as well as by TUNEL analysis. Necrotic cells were found dispersed throughout the exocrine tissue under observation. Both modes of cell death were found highest in extent at days 3 and 7 with 15-20 cells/mm2, but progressively decreased below 10 cells/mm2 up to 28 days after DBTC. By means of in vivo microscopy yellow-green autofluorescent collagen deposits were found at day 7 and progressively increased up to approximately 12% at day 28 after DBTC. Concomitantly, density of capillaries progressively decreased and capillaries failing to conduct blood flow became apparent. Present on-line analysis indicates an early inflammatory response with acinar cell death, most probably triggering progression of disease with collagen deposition, capillary rarefication and manifestation of perfusion failure. These temporal and spatial multiparameter measurements of the in vivo microenvironment provide new insights into the pathological processes of pancreatic fibrogenesis.
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Affiliation(s)
- Claudia Glawe
- Department of Experimental Surgery, University of Rostock, Rostock, Germany
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Li L, Yang L, Kotin RM. The DNA minor groove binding agents Hoechst 33258 and 33342 enhance recombinant adeno-associated virus (rAAV) transgene expression. J Gene Med 2005; 7:420-31. [PMID: 15538728 DOI: 10.1002/jgm.681] [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: 11/09/2022] Open
Abstract
BACKGROUND Recombinant adeno-associated viruses (rAAV) are commonly used in pre-clinical and clinical gene transfer studies. However, the relatively slow kinetics of rAAV transgene expression complicates in vitro and in vivo experiments. METHODS 293 and COS-1 cells were transduced with rAAV2-EGFP, rAAV1-EGFP, or rAAV5-EGFP. The rAAV-EGFP expression was analyzed in the presence of Hoechst 33 258 or 33 342 as a function of time and concentration by flow cytometry and fluorescent microscope. Effects of Hoechst on cell cycle populations were determined by flow cytometry. Enhanced green fluorescent protein (EGFP) expression plasmids with or without AAV inverted terminal repeats (ITR) were constructed and gene expression by transient transfection was compared in the presence of Hoechst. RESULTS We found that Hoechst 33 258 and 33 342 increase both the level and the population of EGFP gene expressing cells, transduced by several different serotypes of rAAV-EGFP. The augmentation of rAAV-EGFP expression occurs in different cell types in a concentration-dependent manner. In addition, the Hoechst 33 258 or 33 342 mediated enhancement of rAAV gene expression correlated with an increase of cells in S phase and G2/M phases of the cell cycle. Finally, gene expression from transfected ITR-containing plasmid DNA was also enhanced by Hoechst dyes. CONCLUSIONS Our results revealed that two different, although related, DNA-binding drugs, Hoechst 33 258 and 33 342, accelerate the kinetics of rAAV transgene expression. These findings may provide the basis for more sensitive assessment of rAAV biological activity and also extend the applications of rAAV for in vivo gene transfer.
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Affiliation(s)
- Lina Li
- Laboratory of Biochemical Genetics, NHLBI, National Institutes of Health, Bethesda, MD 20892, USA
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Chae HJ, Chae SW, Kim HR. Cyclic adenosine monophosphate inhibits nitric oxide-induced apoptosis of cardiac muscle cells in a c-Jun N-terminal kinase-dependent manner. Immunopharmacol Immunotoxicol 2004; 26:249-63. [PMID: 15209361 DOI: 10.1081/iph-120037722] [Citation(s) in RCA: 8] [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] [Indexed: 11/03/2022]
Abstract
Cyclic adenosine monophosphate (cAMP) modulates various agent-induced apoptosis. In this study, we observed that cAMP had a significantly protective effect on nitric oxide (NO)-induced cytotoxicity in H9c2 cardiac muscle cells. Pretreatment with DBcAMP (cAMP analogue) or forskolin (adenylyl cyclase activator) also significantly prevented the SNP-induced apoptosis in H9c2 cells. In contrast, H-89 or KT5720 (PKA inhibitor) reversed the protective effects of DBcAMP. In this study, DBcAMP or forskolin reduced SNP-induced JNK/SAPK activation to the basal level, but KT5720 reversed the inhibitory effects of these two agents. In contrast to JNK/SAPK activation, DBcAMP and forskolin significantly enhanced SNP-activated p38 MAPK phosphorylation and did not affect SNP-mediated ERK activation. KT5720 reversed the effects of DBcAMP and forskolin on p38 MAPK phosphorylation. The inhibition of the JNK pathway by transfection of a dominant negative mutant of JNK/SAPK markedly reduced the extent of SNP-induced cell death. Taken together, we suggest that JNK/SAPK is related to cAMP-protective effect in SNP-induced apoptosis. In addition, c-AMP relating agents protected SNP-induced cell death in neonatal rat ventricular cardiomyocytes. The cAMP-relating agent-induced protective effect is not restricted in H9c2 cardiac muscle cells.
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Affiliation(s)
- Han-Jung Chae
- Department of Pharmacology and Institute of Cardiovascular Research, Chonbuk National University Medical School, South Korea
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Stendahl JC, Li L, Claussen RC, Stupp SI. Modification of fibrous poly(l-lactic acid) scaffolds with self-assembling triblock molecules. Biomaterials 2004; 25:5847-56. [PMID: 15172497 DOI: 10.1016/j.biomaterials.2004.01.042] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Accepted: 01/20/2004] [Indexed: 11/17/2022]
Abstract
Molecular self-assembly offers an effective method to modify the surface properties of common biomaterials by presenting biologically relevant chemistry in a controlled, ordered fashion. This work reports on self-assembling triblock molecules containing rigid cholesteryl segments followed by flexible oligomers of L-(lactic acid) and second generation L-lysine dendrons. Second harmonic generation and small angle X-ray scattering indicate these molecules self-assemble into multilayer polar structures when cast from ethyl acetate solutions and segregate into polar polydomains when annealed. These self-assembled layers significantly improve water wettability when coated onto poly(L-lactic acid) fibers. Scaffolds formed from fibers modified by self-assembly enhance adhesion of 3T3 mouse calvaria cells and produce greater population growth rates. These results demonstrate the use of self-assembly to present biologically relevant chemistry on surfaces of biomaterials. Applications of this technology include the modification of substrates for cell culture, tissue engineering, and cell transplantation.
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Affiliation(s)
- John C Stendahl
- Department of Materials Science and Engineering, Northwestern University, 2220 Campus Dr., Evanston, IL 60208-3108 USA
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Liu JJ, Huang RW, Lin DJ, Peng J, Wu XY, Pan XL, Li MQ, Lin Q. Anti-proliferative Effects of Oridonin on SPC-A-1 Cells and its Mechanism of Action. J Int Med Res 2004; 32:617-25. [PMID: 15587755 DOI: 10.1177/147323000403200606] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [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: 11/16/2022] Open
Abstract
Oridonin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. We investigated the anti-proliferative effect of oridonin on the lung cancer cell line SPC-A-1 and its mechanism of action. Growth inhibition was measured using a microculture tetrazolium assay and apoptosis was measured by several standard methods. Western blot analysis measured the expression of bcl-2 and bax proteins. Oridonin (> 28 μmol/l) inhibited the growth of SPC-A-1 cells and induced apoptosis. Marked morphological changes indicative of apoptosis were observed, especially in cells treated with oridonin for 48–60 h. Western blot analysis revealed downregulation of bcl-2 and upregulation of bax proteins following treatment with oridonin for 48 h. We conclude that oridonin demonstrated anti-proliferative and apoptosis-inducing effects on SPC-A-1 cells in vitro, and that changes in bcl-2 and bax protein levels may play an important role in its mechanism of action.
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Affiliation(s)
- J J Liu
- Department of Haematology and Oncology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Fong S, Liu Y, Heath T, Fong P, Liggitt D, Debs RJ. Membrane-permeant, DNA-binding agents alter intracellular trafficking and increase the transfection efficiency of complexed plasmid DNA. Mol Ther 2004; 10:706-18. [PMID: 15451455 DOI: 10.1016/j.ymthe.2004.06.1016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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: 03/22/2004] [Revised: 06/11/2004] [Accepted: 06/15/2004] [Indexed: 10/26/2022] Open
Abstract
Nuclear delivery of extracellular DNA by nonviral vectors is inhibited by a series of cell membrane and compartmental barriers. Certain cationic amphiphiles that partition through cellular membranes to bind genomic DNA can enhance nuclear delivery of plasmid DNA. Specifically, delivering plasmid DNA complexed to the DNA-binding dye Hoechst 33258 produces cellular transfection levels similar to those achieved by cationic liposome:DNA complexes (CLDC), with less toxicity. Incorporating Hoechst into CLDC or polyethyleneimine:DNA complexes significantly increased reporter gene expression, as well as the percentage of cells transfected. Hoechst:CLDC significantly improved transfection of nondividing cells and efficiently transfected cells in the presence of anionic molecules that block cellular uptake of and transfection by CLDC alone. Hoechst:CLDC also increased gene expression in mouse tissues following intravenous delivery. Delivery of fluorescently labeled plasmid DNA via Hoechst altered its intracellular trafficking by both minimizing lysosomal sequestration and accelerating delivery into the nucleus. Agents such as Hoechst constitute a novel class of nonviral carriers that can confer their membrane-permeant properties on complexed DNA, thus redirecting its intracellular trafficking. In addition, binding of Hoechst 33258 to specific chromosomal DNA target sequences and its ability to modulate transcription may further enhance the expression of delivered genes.
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Affiliation(s)
- Sylvia Fong
- California Pacific Medical Center Research Institute, San Francisco, CA 94115, USA
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Walker J, Saravia NG. INHIBITION OF LEISHMANIA DONOVANI PROMASTIGOTE DNA TOPOISOMERASE I AND HUMAN MONOCYTE DNA TOPOISOMERASES I AND II BY ANTIMONIAL DRUGS AND CLASSICAL ANTITOPOISOMERASE AGENTS. J Parasitol 2004; 90:1155-62. [PMID: 15562618 DOI: 10.1645/ge-3347] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [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: 12/23/2022] Open
Abstract
We have compared the inhibitor sensitivities of DNA topoisomerase I (TOPI) from Leishmania donovani promastigotes and TOPs I and II of human monocytes using pentavalent and trivalent antimonials (SbV, SbIII) and classical TOP inhibitors. Bis-benzimidazoles (Hoechst-33258 and -33342) were potent inhibitors of both parasite and human TOPI, but Hoechst-33342 was markedly less cytotoxic to promastigotes than to monocytes in vitro. Leishmania donovani was also considerably less sensitive than monocytes to camptothecin, both at enzyme and cellular levels. Sodium stibogluconate (SSG) was the only antimonial to inhibit TOPI, exhibiting a significant (P < 0.05) 3-fold greater potency against the L. donovani enzyme but showed low cytotoxicities against intact promastigotes. The SbV meglumine antimoniate failed to inhibit TOPI and showed negligible cytotoxicities, whereas SbIII drugs were lethal to parasites and monocytes yet poor inhibitors of TOPI. Monocyte TOPII was inhibited by bis-benzimidazoles and insensitive to antimonials and camptothecin. The disparity between the high leishmanicidal activity and low anti-TOPI potency of SbIII indicates that in vivo targeting of L. donovani TOPI by the reductive pathway of antimonial activation is improbable. Nevertheless, the potent direct inhibition of TOPI by SSG and the differential interactions of camptothecin with L. donovani and human TOPI support the possibility of developing parasite-specific derivatives.
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Affiliation(s)
- John Walker
- Centro Internacional de Entrenamiento e Investigaciones Medicas Avenida 1 Norte No. 3-03, AA 5390, Cali, Colombia.
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Reddy PM, Dexter R, Bruice TC. DNA sequence recognition in the minor groove by hairpin pyrrole polyamide–Hoechst 33258 analogue conjugate. Bioorg Med Chem Lett 2004; 14:3803-7. [PMID: 15203166 DOI: 10.1016/j.bmcl.2004.04.089] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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] [Received: 02/26/2004] [Revised: 04/27/2004] [Accepted: 04/27/2004] [Indexed: 11/22/2022]
Abstract
A hairpin pyrrole polyamide conjugated to a Hoechst 33258 (Ht) analogue, PyPyPy-gamma-PyPyPy-gamma-Ht, was synthesized on solid-phase by adaptation of an Fmoc technique using a series of PyBOP/HOBt mediated coupling reactions. Sequence selectivity and complex stabilities were characterized by spectrofluorometric titrations and thermal melting studies. The polyamide of the conjugate was observed to bind in a hairpin motif forming 1:1 conjugate:dsDNA complexes. The conjugate is able to recognize nine contiguous A/T bps, discriminating from the sequences containing fewer than nine contiguous A/T bps.
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Affiliation(s)
- Putta Mallikarjuna Reddy
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106, USA
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Xiao Y, de Feyter E, Van Oven CH, Stap J, Hoebe R, Havenith S, Van Noorden CJF, Aten JA. Induction and detection of bystander effects after combined treatment of cells with 5-bromo-2'-deoxyurine, Hoechst 33 258 and ultraviolet A light. Int J Radiat Biol 2004; 80:105-14. [PMID: 15164792 DOI: 10.1080/09553000310001654729] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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: 10/26/2022]
Abstract
PURPOSE A combined treatment of cells with 5-bromo-2'-deoxyurine (BrdU), Hoechst 33 258 and ultraviolet A (UVA) light was used to introduce chromosomal aberrations in cells for the study of bystander effects in non-labelled cells. MATERIALS AND METHODS Mixtures of BrdU-labelled and non-labelled Chinese hamster cells (V79) in S phase were exposed to Hoechst 33 258 and/or UVA light. Metaphase cells were collected and analysed for chromosomal aberrations by Giemsa staining. BrdU immunostaining was performed to verify BrdU incorporation in the cells. RESULTS Combined treatment with BrdU, Hoechst dye and UVA light induced reduced cell survival and increased chromosomal aberrations, whereas treatment with Hoechst 33 258 and/or UVA light had no effect on cells. Elevated frequencies of chromosomal aberrations were found in non-labelled cells mixed with BrdU-labelled cells and exposed to Hoechst dye and UVA light, suggesting the induction of bystander effects by damaged BrdU-labelled cells. These bystander clastogenic effects were also observed in non-labelled cells mixed with dying cells, indicating a contribution of dying cells in the induction of the bystander effects. CONCLUSIONS The combined treatment with BrdU, Hoechst 33 258 and UVA light is a valid method for the study of bystander effects as it enables both induction of DNA damage and discrimination of targeted cells and bystander cells.
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Affiliation(s)
- Y Xiao
- Department of Cell Biology and Histology, Academic Medical Centre, M3-352, University of Amsterdam, PO Box 22700, NL-1100 DE Amsterdam, the Netherlands.
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Satou W, Tanimoto H, Ukekawa R, Fujii M, Ayusawa D. Amplification of nuclear aldolase A in mouse cell mutants resistant to Hoechst 33342. Biochem Biophys Res Commun 2004; 315:845-9. [PMID: 14985089 DOI: 10.1016/j.bbrc.2004.01.142] [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] [Received: 12/01/2003] [Indexed: 11/25/2022]
Abstract
5-Bromodeoxyuridine (BrdU) induces a phenomenon similar to cellular senescence in mammalian cells. AT-binding ligands such as Hoechst 33258 synergistically potentiate the effect of BrdU. We isolated mouse FM3A cell mutants resistant to Hoechst 33342 and characterized two highly resistant mutants. Two-dimensional gel electrophoresis followed by peptides sequence tags revealed that nuclear aldolase A was markedly increased in both mutants. Western blot analysis confirmed that nuclear aldolase A was increased leaving cytosolic aldolase A unaltered. Its mRNA levels were also increased in the mutants. Enforced expression of aldolase A conferred resistance to Hoechst 33342 on wild-type cells. Taken together, nuclear aldolase A was shown to somehow protect the cytotoxic effect of Hoechst 33342.
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Affiliation(s)
- Wataru Satou
- Kihara Institute for Biological Research and Graduate School of Integrated Science, Yokohama City University, Maioka-cho 641-12, Yokohama 244-0813, Japan
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Abstract
Cells are incubated continuously in bromodeoxyuridine (BrdUrd), which is incorporated into cells synthesizing DNA. At intervals, cells are harvested and nuclei are prepared and stained with a bis-benzimidazole, Hoechst 33258, and propidium iodide. In the flow cytometer, the dyes are excited by UV and blue and red fluorescences recorded. BrdUrd quenches the blue fluorescence of the Hoechst dye. The degree of quenching records the progress of the cell through S phase(s); the red (PI) fluorescence yields the cell cycle phases. By this means, the progress of cells around the cell cycle can be followed and the effects of cytotoxic drugs, radiation, and other treatments observed.
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