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Badmus JA, Ekpo OE, Sharma JR, Sibuyi NRS, Meyer M, Hussein AA, Hiss DC. An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells. Molecules 2020; 25:molecules25235716. [PMID: 33287388 PMCID: PMC7730674 DOI: 10.3390/molecules25235716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 09/14/2020] [Revised: 10/11/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022] Open
Abstract
Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentageTM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.
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Affiliation(s)
- Jelili A. Badmus
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
| | - Okobi E. Ekpo
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
| | - Jyoti R. Sharma
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Nicole Remaliah S. Sibuyi
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Mervin Meyer
- DSI/Mintek-Nanotechnology Innovation Centre-BioLabels Node, Department of Biotechnology, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.R.S.); (N.R.S.S.); (M.M.)
| | - Ahmed A. Hussein
- Department of Chemistry, Cape Peninsula University of Technology, 7535 Bellville, Western Cape, South Africa;
| | - Donavon C. Hiss
- Department of Medical Biosciences, University of the Western Cape, 7535 Bellville, Western Cape, South Africa; (J.A.B.); (O.E.E.)
- Correspondence:
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Lupicki K, Elifio-Esposito S, Fonseca AS, Weber SH, Sugita B, Langa BC, Pereira SRF, Govender D, Panieri E, Hiss DC, Abdul-Rasool S, Cavalli LR. Patterns of copy number alterations in primary breast tumors of South African patients and their impact on functional cellular pathways. Int J Oncol 2018; 53:2745-2757. [PMID: 30320392 DOI: 10.3892/ijo.2018.4589] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/24/2018] [Indexed: 11/05/2022] Open
Abstract
Breast cancer is the most common and the leading cause of female mortality among South African (SA) women. Several non‑biological and biological risk factors may be attributed to their observed high mortality rate; however, the molecular profiles associated with their breast tumors are poorly characterized. The present study examined the patterns of genome-wide copy number alterations (CNAs) and their potential impact on functional cellular pathways targeted by cancer driver genes in patients with breast cancer from the Western Cape region of SA. Array-comparative genomic hybridization analysis, performed in 28 cases of invasive breast cancer, revealed a mean number of 8.68±6.18 CNAs per case, affecting primarily the Xp22.3 and 6p21-p25 cytobands (57.14% of the cases), followed by 19p13.3-p13.11 (35.7%), 2p25.3-p24.3, 4p16.3-p15.3, 8q11.1-q24.3 and 16 p13.3-p11.2 (32.14%). Functional enrichment analysis of genes and microRNA targets mapped in these affected cytobands revealed critical cancer-associated pathways, including fatty acid biosynthesis and metabolism, extracellular matrix-receptor interaction, hippo and tumor protein p53 signaling pathways, which are regulated by known cancer genes, including CCND1, CDKN1A, MAPK1, MDM2, TP53 and SMAD2. An inverse correlation was observed among the number of CNAs and tumor size and grade; CNAs on the 4p and 6p cytobands were also inversely correlated with tumor grade. No association was observed in the number of CNAs and/or the affected cytobands and the different ethnic groups of the SA patients, indicating that their tumor genome is affected by CNAs, irrespectively of their genetic descent. Additional genomic tumor profiling in SA and other Sub-Saharan African patients with breast cancer is required to determine the associations of the CNAs observed with prognosis and clinical outcome.
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Affiliation(s)
- Kamil Lupicki
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington DC 20007, USA
| | - Selene Elifio-Esposito
- Department of Health Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná 80215-901, Brazil
| | - Aline S Fonseca
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington DC 20007, USA
| | - Saulo H Weber
- Department of Biotechnology, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná 80215-901, Brazil
| | - Bruna Sugita
- Department of Genetics, Federal University of Parana, Curitiba, Paraná 80060-000, Brazil
| | - Bridget C Langa
- Department of Medical Biosciences, University of the Western Cape, Bellville, Western Cape 7535, South Africa
| | - Silma R F Pereira
- Department of Biology, Federal University of Maranhão, São Luis, Maranhão 65080-805, Brazil
| | - Dhirendra Govender
- Division of Anatomical Pathology, University of Cape Town, National Health Laboratory Service, Groote Schuur Hospital, Cape Town 7700, South Africa
| | - Eugene Panieri
- Department of Surgical Oncology, Groote Schuur Hospital, Cape Town 7700, South Africa
| | - Donavon C Hiss
- Department of Medical Biosciences, University of the Western Cape, Bellville, Western Cape 7535, South Africa
| | - Sahar Abdul-Rasool
- Department of Medical Biosciences, University of the Western Cape, Bellville, Western Cape 7535, South Africa
| | - Luciane R Cavalli
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington DC 20007, USA
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Badmus JA, Ekpo OE, Rautenbach F, Marnewick JL, Hussein AA, Hiss DC. Isolation and antioxidant activity of flavonoids from Holarrhena floribunda (G.don) leaves. Acta Biochim Pol 2016; 63:353-8. [PMID: 27172363 DOI: 10.18388/abp.2015_1178] [Citation(s) in RCA: 5] [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: 08/17/2015] [Revised: 01/13/2016] [Accepted: 02/11/2016] [Indexed: 11/10/2022]
Abstract
Bioactive polyphenolics are ubiquitously present in plants and may play an important role in the prevention and management of certain human diseases. Three known flavonoids viz Kaemperol-3-O-rutinoside (1), quercetin-3-O-glucoside (2) and kaemperol-3-O-glucoside (3) and inseparable mixture (1:1) of quercetin-3-O-glucose/galactose (4) were isolated, and identified for the first time from Holarrhena floribunda. The antioxidant capacity using the ORAC, FRAP and TEAC assays and inhibition of lipid peroxidation were measured for isolated flavonoids. The result showed that compounds 2 and 4 showed significantly increased ORAC, TEAC, and FRAP activities with low pro-oxidant potential as well as improved lipid peroxidation inhibition levels when compared to compounds 1 and 3. The most active compounds were found to be flavonoids with a quercetin basic structure. These results imply that the isolated flavonoid glycosides are responsible for the antioxidant activity of the plant leaves and it forms the scientific basis for its traditional usage.
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Affiliation(s)
- Jelili A Badmus
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Okobi E Ekpo
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Fanie Rautenbach
- Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town South Africa
| | - Jeanine L Marnewick
- Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town South Africa
| | - Ahmed A Hussein
- Department of Chemistry, University of the Western Cape, Chemical Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
| | - Donavon C Hiss
- Department of Medical Biosciences, University of the Western Cape, New Life Sciences Building, Private Bag X17 Bellville, Cape Town 7535, South Africa
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Badmus JA, Odunola OA, Yekeen TA, Gbadegesin AM, Fatoki JO, Godo MO, Oyebanjo KS, Hiss DC. Evaluation of antioxidant, antimutagenic, and lipid peroxidation inhibitory activities of selected fractions of Holarrhena floribunda (G. Don) leaves. Acta Biochim Pol 2013; 60:435-442. [PMID: 24020060] [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] [Received: 02/28/2013] [Revised: 06/28/2013] [Accepted: 07/24/2013] [Indexed: 06/02/2023]
Abstract
Exposure to environmental pollutants often leads to an upsurge in the production of reactive oxygen species (ROS). ROS oxidize cellular fatty acids to produce lipid peroxyl radicals, subsequently transformed into lipid peroxides, which decrease membrane fluidity and increase the activity of various enzymes implicated in degenerative diseases and cancer formation. Edible plants that contain exogenous compounds like curcumeroid, β-carotene, turmeric, and so on, protect the aerobic cells from oxidation of free radicals. This study thus evaluates antioxidant and antimutagenic activities of ethyl acetate, aqueous and methanolic fractions of Holarrhena floribunda leaves. Inhibitory activities of the ethyl acetate fraction on Fe(2+)-induced lipid peroxidation in hen egg yolk; rat liver and brain tissues were also evaluated. The Allium cepa root assay was used to evaluate antimutagenic activity. Results showed that the ethyl acetate scavenged DPPH, OH•, and •O2(-) much stronger than other fractions, as evidenced by its lowest respective IC50 values. All the fractions displayed antimutagenic activities against cyclophosphamide-induced chromosomal aberrations. Likewise, all the fractions induced a reduction in mitotic index, a hallmark of cytotoxicity in the root meristem of Allium cepa. The decrease in mitotic index was most profound for the ethyl acetate fraction, which also demonstrated a significant lipid peroxidation inhibitory activity in the liver and brain homogenates, but not in egg yolk, compared with the ascorbic acid standard. In general, the results suggest that the ethyl acetate fraction might contain beneficial phytochemicals that should be explored as novel candidates for preclinical drug development.
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Affiliation(s)
- Jelili A Badmus
- Molecular Oncology Laboratory, Department of Medical Biosciences, University of the Western Cape, South Africa and Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
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5
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Badmus JA, Odunola OA, Yekeen TA, Gbadegesin AM, Fatoki JO, Godo MO, Oyebanjo KS, Hiss DC. Evaluation of antioxidant, antimutagenic, and lipid peroxidation inhibitory activities of selected fractions of Holarrhena floribunda (G. Don) leaves. Acta Biochim Pol 2013. [DOI: 10.18388/abp.2013_2004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Exposure to environmental pollutants often leads to an upsurge in the production of reactive oxygen species (ROS). ROS oxidize cellular fatty acids to produce lipid peroxyl radicals, subsequently transformed into lipid peroxides, which decrease membrane fluidity and increase the activity of various enzymes implicated in degenerative diseases and cancer formation. Edible plants that contain exogenous compounds like curcumeroid, β-carotene, turmeric, and so on, protect the aerobic cells from oxidation of free radicals. This study thus evaluates antioxidant and antimutagenic activities of ethyl acetate, aqueous and methanolic fractions of Holarrhena floribunda leaves. Inhibitory activities of the ethyl acetate fraction on Fe(2+)-induced lipid peroxidation in hen egg yolk; rat liver and brain tissues were also evaluated. The Allium cepa root assay was used to evaluate antimutagenic activity. Results showed that the ethyl acetate scavenged DPPH, OH•, and •O2(-) much stronger than other fractions, as evidenced by its lowest respective IC50 values. All the fractions displayed antimutagenic activities against cyclophosphamide-induced chromosomal aberrations. Likewise, all the fractions induced a reduction in mitotic index, a hallmark of cytotoxicity in the root meristem of Allium cepa. The decrease in mitotic index was most profound for the ethyl acetate fraction, which also demonstrated a significant lipid peroxidation inhibitory activity in the liver and brain homogenates, but not in egg yolk, compared with the ascorbic acid standard. In general, the results suggest that the ethyl acetate fraction might contain beneficial phytochemicals that should be explored as novel candidates for preclinical drug development.
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Maputle MS, Hiss DC. Criteria to facilitate the implementation of woman-centred care in childbirth units of Limpopo Province, South Africa (Part 2). Curationis 2013; 36:E1-7. [PMID: 23718863 DOI: 10.4102/curationis.v36i1.50] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 04/15/2013] [Accepted: 03/18/2013] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Facilitation of mutual participation, respectful and egalitarian relationship between the mother and the midwife during childbirth is a critical aspect. This article delineated the criteria that would facilitate the implementation of woman-centred care in childbirth units of the Limpopo Province in South Africa, following a concept analysis described in Part 1. Empirical referents or indicators were used to measure the concept woman-centred care and to validate its existence in reality. These empirical referents were referred to as measurable properties that further verified the concept. OBJECTIVE The objective of this article was to formulate criteria that would facilitate implementation of woman-centred care in childbirth units of Limpopo Province in South Africa. METHOD Criteria to facilitate the implementation of woman-centred care were formulated by the gathering of information about the topic under review and the use of resources to define the key elements of the criteria which were integrated into the Batho Pele principles. The criteria were then validated by selecting with a vested interest in the successful development and implementation of the criteria. RESULTS Criteria were formulated to facilitate the implementation of woman-centred care that was integrated within the framework of Batho Pele principles. CONCLUSION These formulated criteria for woman-centred care will be used as an institutional self-evaluation tool to enhance implementation of the Batho Pele principles in childbirth units. These criteria will give direction and provide guidelines for the performance of midwifery staff and will also help supervisors to guide staff to improve performance.
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Affiliation(s)
- Maria S Maputle
- Department of Advanced Nursing Science, University of Venda.
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Abstract
INTRODUCTION Oncolytic viruses (OVs) occupy a strategic niche in the dynamic era of biological and gene therapy of human cancers. However, the use of OVs is the subject of close scrutiny due to impediments such as the insufficiency of patient generalizations posed by heterogeneous tumor responses to treatment, inherent or potentially lethal viral pathogenicities, unanticipated host- or immune-related adverse effects, and the emergence of virus-resistant cancer cells. These challenges can be overcome by the design and development of more definitive (optimized, targeted, and individualized) cancer virotherapeutics. AREAS COVERED The translation of current knowledge and recent innovations into rational treatment prospects hinges on an iterative loop of variables pertaining to genetically engineered viral oncolytic efficacy and safety profiles, mechanism-of-action data, potencies of synergistic oncolytic viral combinations with conventional tumor, immuno-, chemo-, and radiation treatment modalities, optimization of the probabilities of treatment successes in heterogeneous (virus-sensitive and -resistant) tumor cell populations by mathematical modeling, and lessons learned from preclinical studies and human clinical trials. EXPERT OPINION In recent years, it has become increasingly clear that proof-of-principle is critical for the preclinical optimization of oncolytic viruses to target heterogeneous forms of cancer and to prioritize current concerns related to the efficacy and safety of oncolytic virotherapy.
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Affiliation(s)
- Donavon C Hiss
- University of the Western Cape, Department of Medical Biosciences, Molecular Oncology Research Laboratory, Bellville, 7535, South Africa.
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Abstract
INTRODUCTION The objective of this study was to explore and describe the experiences of midwives managing women during labour at a tertiary care hospital in the Limpopo Province. An exploratory, descriptive, contextual and inductive design was applied to this qualitative research study. Purposive sampling was used to select midwives who were working in the childbirth unit and had managed women during labour. A sample of 12 midwives participated in this study. Data were collected by means of unstructured individual interviews and analysed through an open coding method by the researchers and the independent co-coder. FINDINGS Categories identified were lack of mutual participation and responsibility sharing, dependency and lack of decision-making, lack of information-sharing, empowering autonomy and informed choices opportunities, lack of open communication and listening, non-accommodative midwifery actions, and lack of human and material infrastructure. To ensure the validity of the results, criteria to measure trustworthiness were utilized. CONCLUSIONS This study has implications for woman-centered care by midwives managing women in labour and provides appropriate guidelines that should be integrated into the Batho-Pele Principles.
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Affiliation(s)
- S M Maputle
- University of Venda, Department of Advanced Nursing Sience.
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Hiss DC, Gabriels GA. Implications of endoplasmic reticulum stress, the unfolded protein response and apoptosis for molecular cancer therapy. Part II: targeting cell cycle events, caspases, NF-κB and the proteasome. Expert Opin Drug Discov 2009; 4:907-21. [PMID: 23480539 DOI: 10.1517/17460440903055032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Endoplasmic reticulum stress (ERS), the unfolded protein response (UPR) and apoptosis signal transduction pathways are fundamental to normal cellular homeostasis and survival, but are exploited by cancer cells to promote the cancer phenotype. OBJECTIVE Collateral activation of ERS and UPR role players impact on cell growth, cell cycle arrest or apoptosis, genomic stability, tumour initiation and progression, tumour aggressiveness and drug resistance. An understanding of these processes affords promising prospects for specific cancer drug targeting of the ERS, UPR and apoptotic pathways. METHOD This review (Part II of II) brings forward the latest developments relevant to the molecular connections among cell cycle regulators, caspases, NF-κB, and the proteasome with ERS and UPR signalling cascades, their functions in apoptosis induction, apoptosis resistance and oncogenesis, and how these relationships can be exploited for targeted cancer therapy. CONCLUSION Overall, ERS, the UPR and apoptosis signalling cascades (the molecular therapeutic targets) and the development of drugs that attack these targets signify a success story in cancer drug discovery, but a more reductionist approach is necessary to determine the precise molecular switches that turn on antiapoptotic and pro-apoptotic programmes.
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Affiliation(s)
- Donavon C Hiss
- Head, Molecular Oncology Research Programme, University of the Western Cape, Department of Medical BioSciences, Bellville, 7535, South Africa +27 21 959 2334 ; +27 959 1563 ;
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Hiss DC, Gabriels GA. Implications of endoplasmic reticulum stress, the unfolded protein response and apoptosis for molecular cancer therapy. Part I: targeting p53, Mdm2, GADD153/CHOP, GRP78/BiP and heat shock proteins. Expert Opin Drug Discov 2009; 4:799-821. [PMID: 23496268 DOI: 10.1517/17460440903052559] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND In eukaryotes, endoplasmic reticulum stress (ERS) and the unfolded protein response (UPR) are coordinately regulated to maintain steady-state levels and activities of various cellular proteins to ensure cell survival. OBJECTIVE This review (Part I of II) focuses on specific ERS and UPR signalling regulators, their expression in the cancer phenotype and apoptosis, and proposes how their implication in these processes can be rationalised into proteasome inhibition, apoptosis induction and the development of more efficacious targeted molecular cancer therapies. METHOD In this review, we contextualise many ERS and UPR client proteins that are deregulated or mutated in cancers and show links between ERS and the UPR, their implication in oncogenic transformation, tumour progression and escape from immune surveillance, apoptosis inhibition, angiogenesis, metastasis, acquired drug resistance and poor cancer prognosis. CONCLUSION Evasion of programmed cell death or apoptosis is a hallmark of cancer that enables tumour cells to proliferate uncontrollably. Successful eradication of cancer cells through targeting ERS- and UPR-associated proteins to induce apoptosis is currently being pursued as a central tenet of anticancer drug discovery.
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Affiliation(s)
- Donavon C Hiss
- Head, Molecular Oncology Research Programme University of the Western Cape, Department of Medical BioSciences, Bellville, 7535, South Africa +27 21 959 2334 ; +27 21 959 1563 ;
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Hiss DC, Gabriels GA, Folb PI. Combination of tunicamycin with anticancer drugs synergistically enhances their toxicity in multidrug-resistant human ovarian cystadenocarcinoma cells. Cancer Cell Int 2007; 7:5. [PMID: 17439664 PMCID: PMC1865531 DOI: 10.1186/1475-2867-7-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 04/18/2007] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The pharmacologic modulatory effects of the antibiotic, tunicamycin (TM), on multidrug-resistant human UWOV2 ovarian cancer cells are reported. The UWOV2 cell line was derived from a cystadenocarcinoma in a patient refractory to combination chemotherapy with actinomycin D, vincristine (VCR), cis-diaminedichloroplatinum (II) (CDDP) and doxorubicin (DXR). In an attempt to explain drug resistance in this cell line, we examined the effects of TM on their sensitivity to various anticancer drugs, the uptake, efflux and retention of [3H]VCR, and their ability to bind [14C]DXR and [3H]azidopine (AZD), a photoaffinity label of the multidrug transporter, P-glycoprotein (Pgp). RESULTS TM effectively decreased the EC50 for DXR, EXR, VCR and CDDP, thus enhancing their cytotoxicity. The antibiotic also prolonged the intracellular retention time of [3H]VCR and increased the binding of both [14C]DXR and [3H]AZD to the cells. CONCLUSION It is concluded that the pharmacomodulatory effects of TM in these cells are mediated by global inhibition of protein and glycoprotein synthesis and synergistic interaction with antineoplastic drugs. The ability of TM to enhance the sensitivity of drug resistant tumour cells may have impact on the design and optimization of novel resistance modifiers to improve the efficacy of combination treatment of intractable neoplasms.
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Affiliation(s)
- Donavon C Hiss
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925, South Africa
- Department of Medical BioSciences, University of the Western Cape, 7535, Bellville, South Africa
| | - Gary A Gabriels
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925, South Africa
| | - Peter I Folb
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, 7925, South Africa
- Medical Research Council, 7505, Tygerberg, South Africa
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Mosane TW, Malope BI, Ratshikhopha ME, Hiss DC, Sitas F. Seroprevalence of Helicobacter pylori immunoglobulin G antibodies in South African mothers and their children. Eur J Gastroenterol Hepatol 2004; 16:113-4. [PMID: 15095861 DOI: 10.1097/00042737-200401000-00017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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Abstract
Laboratory tests used in the diagnosis of iron status lack specificity in defining iron deficiency anaemia (IDA) and anaemia of inflammation (AI). The serum transferrin receptor (sTfR) may provide more information in this regard. The iron status of 561 pre-school children was determined and classified using the conventional measurements. The value of the concentration of sTfR, the ratio of sTfR (microg/ml) to LogSF (microg/l) (TfR-Index), and the Log of the ratio of sTfR (microg/l) to SF (microg/l)--(LogTfR:Fer ratio), in the classification of the iron status were determined by comparing their distributions across the classification of iron status. Although there were significant differences in sTfR and TfR-Index across the categories of iron status, there was considerable overlap. All subjects with iron deficiency had LogTfR:Fer ratio > 2.55, whereas in all subjects classified as AI it was < 2.55, thus clearly separating the two. The LogTfR:Fer ratio was not able to exclude IDA in the presence of inflammation. However, in cases of combined IDA and AI the LogTfR:Fer ratio was < 2.55 but increased to > 2.55 after resolution of the inflammation. This novel method of calculating the LogTfR:Fer ratio may provide a more precise classification of the iron status of children.
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Affiliation(s)
- B I Malope
- Department of Medical Sciences, University of the North, Sovenga, South Africa
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