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Tyavambiza C, Meyer M, Wusu AD, Madiehe A, Meyer S. The Cytotoxicity of Cotyledon orbiculata Aqueous Extract and the Biogenic Silver Nanoparticles Derived from the Extract. Curr Issues Mol Biol 2023; 45:10109-10120. [PMID: 38132477 PMCID: PMC10742177 DOI: 10.3390/cimb45120631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023] Open
Abstract
Green synthesized silver nanoparticles (AgNPs) have become popular because of their promising biological activities. However, for most of these nanoparticles, the cytotoxic effects have not been determined and their safety is not guaranteed. In a previous study, we successfully synthesized AgNPs (Cotyledon-AgNPs) using an extract of Cotyledon orbiculata, a medicinal plant traditionally used in South Africa to treat skin conditions. Cotyledon-AgNPs were shown to have significant antimicrobial and wound-healing activities. Fibroblast cells treated with extracts of C. orbiculata and Cotyledon-AgNPs demonstrated an enhanced growth rate, which is essential in wound healing. These nanoparticles therefore have promising wound-healing activities. However, the cytotoxicity of these nanoparticles is not known. In this study, the toxic effects of C. orbiculata extract and Cotyledon-AgNPs on the non-cancerous skin fibroblast (KMST-6) were determined using in vitro assays to assess oxidative stress and cell death. Both the C. orbiculata extract and the Cotyledon-AgNPs did not show any significant cytotoxic effects in these assays. Gene expression analysis was also used to assess the cytotoxic effects of Cotyledon-AgNPs at a molecular level. Of the eighty-four molecular toxicity genes analysed, only eight (FASN, SREBF1, CPT2, ASB1, HSPA1B, ABCC2, CASP9, and MKI67) were differentially expressed. These genes are mainly involved in fatty acid and mitochondrial energy metabolism. The results support the finding that Cotyledon-AgNPs have low cytotoxicity at the concentrations tested. The upregulation of genes such as FASN, SERBF1, and MKI-67 also support previous findings that Cotyledon-AgNPs can promote wound healing via cell growth and proliferation. It can therefore be concluded that Cotyledon-AgNPs are not toxic to skin fibroblast cells at the concentration that promotes wound healing. These nanoparticles could possibly be safely used for wound healing.
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Affiliation(s)
- Caroline Tyavambiza
- Department of Science and Innovation–Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Cape Town 7530, South Africa; (C.T.); (M.M.); (A.D.W.); (A.M.)
- Department of Biomedical Sciences, Cape Peninsula University of Technology, Cape Town 7535, South Africa
| | - Mervin Meyer
- Department of Science and Innovation–Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Cape Town 7530, South Africa; (C.T.); (M.M.); (A.D.W.); (A.M.)
| | - Adedoja Dorcas Wusu
- Department of Science and Innovation–Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Cape Town 7530, South Africa; (C.T.); (M.M.); (A.D.W.); (A.M.)
| | - Abram Madiehe
- Department of Science and Innovation–Mintek Nanotechnology Innovation Centre, Department of Biotechnology, University of the Western Cape, Cape Town 7530, South Africa; (C.T.); (M.M.); (A.D.W.); (A.M.)
- Nanobiotechnology Research Group, Department of Biotechnology, Faculty of Natural Sciences, University of the Western Cape, Cape Town 7530, South Africa
| | - Samantha Meyer
- Department of Biomedical Sciences, Cape Peninsula University of Technology, Cape Town 7535, South Africa
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Aboyewa JA, Sibuyi NRS, Goboza M, Murtz LA, Oguntibeju OO, Meyer M. Co-Treatment of Caco-2 Cells with Doxorubicin and Gold Nanoparticles Produced from Cyclopia intermedia Extracts or Mangiferin Enhances Drug Effects. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3918. [PMID: 36364694 PMCID: PMC9654788 DOI: 10.3390/nano12213918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
Mangiferin (MGF) is a natural and valuable polyphenol found in significant levels in many plant species, including Cyclopia intermedia (C. intermedia). In a previous study, we synthesized gold nanoparticles (AuNPs) using MGF and a water extract of C. intermedia and reported that these AuNPs have very low cytotoxicity toward a human colon cancer (Caco-2) cell line. Although the study also showed that these biogenic AuNPs in combination with doxorubic (DOX) significantly augmented the cytotoxic effects of DOX in Caco-2 cells, the mechanism of the enhanced effect was not fully understood, and it was also not known if other cell lines would be sensitive to this co-treatment. In the present study, we examined the cytotoxicity of the co-treatment in Caski, HeLa, HT-29, KMST-6 and MDA-321 cell lines. Additionally, we investigated the mechanistic effects of this co-treatment in Caco-2 cells using several assays, including the adenosine triphosphate (ATP), the oxidative stress, the mitochondrial depolarization, the colony formation, the APOPercentage and the DNA fragmentation assays. We also assessed the intracellular uptake of the biogenic AuNPs. The study showed that the biogenic AuNPs were effectively taken up by the cancer cells, which, in turn, may have enhanced the sensitivity of Caco-2 cells to DOX. Moreover, the combination of the biogenic AuNPs and DOX caused a rapid depletion of ATP levels, increased mitochondrial depolarization, induced apoptosis, reduced the production of reactive oxygen species (ROS) and inhibited the long-term survival of Caco-2 cells. Although the study provided some insight into the mechanism of cytotoxicity induced by the co-treatment, further mechanistic and molecular studies are required to fully elucidate the enhanced anticancer effect of the co-treatment.
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Affiliation(s)
- Jumoke A. Aboyewa
- Phytomedicine and Phytochemistry Group, Oxidative Stress Research Centre, Department of Biomedical Sciences, Cape Peninsula University of Technology, Bellville 7535, South Africa
- DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
| | - Nicole R. S. Sibuyi
- DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
| | - Mediline Goboza
- DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
| | - Lee-Ann Murtz
- DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
| | - Oluwafemi O. Oguntibeju
- Phytomedicine and Phytochemistry Group, Oxidative Stress Research Centre, Department of Biomedical Sciences, Cape Peninsula University of Technology, Bellville 7535, South Africa
| | - Mervin Meyer
- DSI/Mintek Nanotechnology Innovation Centre, Biolabels Node, Department of Biotechnology, University of the Western Cape, Bellville 7530, South Africa
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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: 1.0] [Reference Citation Analysis] [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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Mbugua S, Sibuyi NRS, Njenga LW, Odhiambo RA, Wandiga SO, Meyer M, Lalancette RA, Onani MO. New Palladium(II) and Platinum(II) Complexes Based on Pyrrole Schiff Bases: Synthesis, Characterization, X-ray Structure, and Anticancer Activity. ACS OMEGA 2020; 5:14942-14954. [PMID: 32637768 PMCID: PMC7330904 DOI: 10.1021/acsomega.0c00360] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 05/14/2020] [Indexed: 05/09/2023]
Abstract
New palladium (Pd)II and platinum (Pt)II complexes (C1-C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan-2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) are herein reported. The complexes (C1-C5) were characterized by FTIR, 1H and 13C NMR, UV-vis, and microanalyses. Single-crystal X-ray crystallographic analysis was performed for the two ligands (L1-L2) and a Pt complex. Both L1 and L2 belong to P21/n monoclinic and P-1 triclinic space systems, respectively. The complex C5 belongs to the P21/c monoclinic space group. The investigated molar conductivity of the complexes in DMSO gave the range 4.0-8.8 μS/cm, suggesting neutrality, with log P values ≥ 1.2692 ± 0.004, suggesting lipophilicity. The anticancer activity and mechanism of the complexes were investigated against various human cancerous (Caco-2, HeLa, HepG2, MCF-7, and PC-3) and noncancerous (MCF-12A) cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Apopercentage assays, respectively. C5 demonstrated strong DNA-binding affinity for calf thymus DNA (CT-DNA) with a binding constant of 8.049 × 104 M-1. C3 reduced cell viability of all the six cell lines, which included five cancerous cell lines, by more than 80%. The C5 complex also demonstrated remarkably high selectivity with no cytotoxic activity toward the noncancerous breast cell line but reduced the viability of the five cancerous cell lines, which included one breast cancer cell line, by more than 60%. Further studies are required to evaluate the selective toxicity of these two complexes and to fully understand their mechanism of action.
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Affiliation(s)
- Simon
N. Mbugua
- Organometallics
and Nanomaterials, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
- Department
of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya
| | - Nicole R. S. Sibuyi
- Department
of Science and Technology/Mintek Nanotechnology Innovation Centre
(DST/Mintek NIC), Biolabels Node, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Lydia W. Njenga
- Department
of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya
| | - Ruth A. Odhiambo
- Department
of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya
| | - Shem O. Wandiga
- Department
of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya
| | - Mervin Meyer
- Department
of Science and Technology/Mintek Nanotechnology Innovation Centre
(DST/Mintek NIC), Biolabels Node, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Roger A. Lalancette
- Rutgers,
Department of Chemistry, Rutgers State University, 73 Warren St., Newark, New Jersey 07102, United States
| | - Martin O. Onani
- Organometallics
and Nanomaterials, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
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Ayo-Lawal RA, Osoniyi O, Sibuyi NRS, Meyer M, Ekpo O. Cytotoxic and Apoptotic Induction Potential of Extracts from Fermented Citrullus vulgaris Thunb. Seeds on Cervical and Liver Cancer Cells. J Diet Suppl 2020; 18:132-146. [PMID: 32114858 DOI: 10.1080/19390211.2020.1731045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The anti-cancer activities of many fermented foods and beverages are now scientifically established. Ogiri-egusi is a condiment prepared from fermentation of Citrullus vulgaris (melon) seeds and consumed in many countries of West Africa. Its anti-oxidative and anti-hyperlipidaemic properties have been reported. This study investigated the anti-cancer activities of the aqueous and methanolic extracts from ogiri-egusi. Cytotoxicity was investigated using the MTT and colony-formation inhibition assays while flow-cytometer based Apopercentage assay was used to quantify apoptosis in extracts-treated cervical and liver cancer and normal human fibroblast cells. The inhibitory concentration responsible for killing 50% of cells after 24 h by the aqueous extract in KMST-6, HeLa, and Hep-G2 cells were estimated at 1.610, 1.020, and 1.507 mg/mL respectively. While these values reduced with increasing incubation time in cancer cells it increased in the non-cancer cell. Furthermore, the extract significantly induced apoptosis in HeLa (97 ± 0.18%) and Hep-G2 (73 ± 6.73%) cells. These findings were corroborated by cells morphologic presentations and inhibition of colony formation assay. These findings suggest that the aqueous extract from fermented Citrullus vulgaris seeds might be a nutraceutical with potential anti-cancer properties.
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Affiliation(s)
- Rachael Aderonke Ayo-Lawal
- National Centre for Technology Management (NACETEM), Obafemi Awolowo University, Ile-Ife, Nigeria.,Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Omolaja Osoniyi
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Nicole Remaliah Samantha Sibuyi
- Department of Science and Technology/Mintek Nanotechnology Innovation Centre, Biolabels Unit, Department of Biotechnology, University of the Western Cape, Bellville, Cape Town, South Africa
| | - Mervin Meyer
- Department of Science and Technology/Mintek Nanotechnology Innovation Centre, Biolabels Unit, Department of Biotechnology, University of the Western Cape, Bellville, Cape Town, South Africa
| | - Okobi Ekpo
- Department of Medical Bioscience, University of the Western Cape, Bellville, Cape Town, South Africa
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Hanna DH, Saad GR. Nanocurcumin: preparation, characterization and cytotoxic effects towards human laryngeal cancer cells. RSC Adv 2020; 10:20724-20737. [PMID: 35517737 PMCID: PMC9054308 DOI: 10.1039/d0ra03719b] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 05/11/2020] [Indexed: 11/21/2022] Open
Abstract
The aim of the present study was to prepare curcumin nanoparticles (nanocurcumin) by a sol-oil method to improve curcumin absorption and bioavailability, and to investigate the therapeutic effects of the prepared nanoparticles on the inhibition mechanisms towards human Hep-2 cancer cells. The nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and zeta potential analysis. The prepared curcumin nanoparticles possessed a narrow particle size distribution with an average diameter of 28 nm. The inhibition effects on the growth of human Hep-2 cells were investigated using neutral red uptake and lactate dehydrogenase assays. The results indicated that the nanocurcumin has a selective effect in inhibiting Hep-2 cell growth in a dose- and time-dependent mode with the most effective IC50 value (17 ± 0.31 μg ml−1) obtained after 48 h of incubation without any cytotoxic effects on normal cells. This IC50 value of nanocurcumin revealed a significant increase of early and late apoptotic cells with an intense comet nucleus of Hep-2 cells as a marker of DNA damage. Flow cytometry analysis of the progression of apoptosis in nanocurcumin Hep-2 treated cells showed that arresting in the cell cycle in the G2/M phase with increasing apoptotic cells in the sub-G1 phase. At the same time, real-time PCR analysis indicated that the treatment of Hep-2 cells with nanocurcumin resulted in upregulation of P53, Bax, and Caspase-3, whereas there was downregulation of Bcl-XL. These findings gave insights into understanding that the inhibition mechanisms of nanocurcumin on the proliferation of Hep-2 cancer cells was through the G2/M cell cycle arrest and the induction of apoptosis was dependent on Caspase-3 and p53 activation. However, in vivo studies with an animal model are essential to validate these results. The aim of this study was to prepare curcumin nanoparticles using a sol–oil method to improve curcumin absorption and bioavailability, and to investigate the therapeutic effect of the prepared nanoparticles on the inhibition mechanisms toward human Hep-2 cancer cells.![]()
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Affiliation(s)
- Demiana H. Hanna
- Department of Chemistry
- Faculty of Science
- Cairo University
- Giza 12613
- Egypt
| | - Gamal R. Saad
- Department of Chemistry
- Faculty of Science
- Cairo University
- Giza 12613
- Egypt
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Sundstrøm T, Prestegarden L, Azuaje F, Aasen SN, Røsland GV, Varughese JK, Bahador M, Bernatz S, Braun Y, Harter PN, Skaftnesmo KO, Ingham ES, Mahakian LM, Tam S, Tepper CG, Petersen K, Ferrara KW, Tronstad KJ, Lund-Johansen M, Beschorner R, Bjerkvig R, Thorsen F. Inhibition of mitochondrial respiration prevents BRAF-mutant melanoma brain metastasis. Acta Neuropathol Commun 2019; 7:55. [PMID: 30971321 PMCID: PMC6456988 DOI: 10.1186/s40478-019-0712-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/27/2019] [Indexed: 01/12/2023] Open
Abstract
Melanoma patients carry a high risk of developing brain metastases, and improvements in survival are still measured in weeks or months. Durable disease control within the brain is impeded by poor drug penetration across the blood-brain barrier, as well as intrinsic and acquired drug resistance. Augmented mitochondrial respiration is a key resistance mechanism in BRAF-mutant melanomas but, as we show in this study, this dependence on mitochondrial respiration may also be exploited therapeutically. We first used high-throughput pharmacogenomic profiling to identify potentially repurposable compounds against BRAF-mutant melanoma brain metastases. One of the compounds identified was β-sitosterol, a well-tolerated and brain-penetrable phytosterol. Here we show that β-sitosterol attenuates melanoma cell growth in vitro and also inhibits brain metastasis formation in vivo. Functional analyses indicated that the therapeutic potential of β-sitosterol was linked to mitochondrial interference. Mechanistically, β-sitosterol effectively reduced mitochondrial respiratory capacity, mediated by an inhibition of mitochondrial complex I. The net result of this action was increased oxidative stress that led to apoptosis. This effect was only seen in tumor cells, and not in normal cells. Large-scale analyses of human melanoma brain metastases indicated a significant role of mitochondrial complex I compared to brain metastases from other cancers. Finally, we observed completely abrogated BRAF inhibitor resistance when vemurafenib was combined with either β-sitosterol or a functional knockdown of mitochondrial complex I. In conclusion, based on its favorable tolerability, excellent brain bioavailability, and capacity to inhibit mitochondrial respiration, β-sitosterol represents a promising adjuvant to BRAF inhibitor therapy in patients with, or at risk for, melanoma brain metastases.
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Pu J, Zhu S, Zhou D, Zhao L, Yin M, Wang Z, Hong J. Propofol Alleviates Apoptosis Induced by Chronic High Glucose Exposure via Regulation of HIF-1 α in H9c2 Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4824035. [PMID: 31093315 PMCID: PMC6481038 DOI: 10.1155/2019/4824035] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/26/2019] [Accepted: 02/04/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND The sedative anesthetic, propofol, is a cardioprotective agent for hyperglycemia-induced myocardial hypertrophy and dysfunction in rats. However, the specific protective mechanism has not been clarified. METHODS AND RESULTS In this experiment, we used H9c2 cells subjected to 22 mM glucose lasting for 72 hours as an in vitro model of cardiomyocyte injury by hyperglycemia and investigated the potential mechanism of propofol against hyperglycemic stress in cells. Propofol (5, 10, or 20 μM) was added to the cell cultures before and during the high glucose culture phases. Cell viability and levels of ROS were measured. The levels of proinflammatory cytokines were tested by ELISA. The levels of SIRT3, SOD2, PHD2, HIF-1α, Bcl-2, P53, and cleaved caspase-3 proteins were detected by western blotting. Our data showed that propofol attenuated high glucose-induced cell apoptosis accompanied by a decrease in the level of reactive oxygen species (ROS) and proinflammatory cytokines. Meanwhile, propofol decreased the apoptosis of H9c2 cells via increasing the expression of Bcl-2, SIRT3, SOD2, and PHD2 proteins and decreasing the expression of cleaved caspase-3, P53, and HIF-1α. Real-time PCR analysis showed that propofol did not significantly change the HIF-1α but increase PHD2 at mRNA level. HIF-1α silence significantly decreased apoptosis and inflammation in H9c2 cell during high glucose stress. Pretreatment of IOX2 (the inhibitor of PHD2) inhibited cell viability until the concentration reached 200 μM during high glucose stress. However, 50 μM TYP (the inhibitor of SIRT3) significantly inhibited cell viability during high glucose stress. Delayed IOX2 treatment for 6 hours significantly inhibited cell viability during high glucose stress. CONCLUSIONS Propofol might alleviate cell apoptosis via SIRT3-HIF-1α axis during high glucose stress.
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Affiliation(s)
- Jinjun Pu
- 1Department of Internal and Emergency Medicine, Shanghai General Hospital (Originally Named Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
- 2Department of Emergency Medicine, Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shun Zhu
- 1Department of Internal and Emergency Medicine, Shanghai General Hospital (Originally Named Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dandan Zhou
- 1Department of Internal and Emergency Medicine, Shanghai General Hospital (Originally Named Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lidong Zhao
- 1Department of Internal and Emergency Medicine, Shanghai General Hospital (Originally Named Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming Yin
- 3School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Zejian Wang
- 3School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Jiang Hong
- 1Department of Internal and Emergency Medicine, Shanghai General Hospital (Originally Named Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Naqvi S, Mohiyuddin S, Gopinath P. Niclosamide loaded biodegradable chitosan nanocargoes: an in vitro study for potential application in cancer therapy. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170611. [PMID: 29291056 PMCID: PMC5717630 DOI: 10.1098/rsos.170611] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 09/12/2017] [Indexed: 05/08/2023]
Abstract
Chitosan nanoparticles can advance the pharmacological and therapeutic properties of chemotherapeutic agents by controlling release rates and targeted delivery process, which eliminates the limitations of conventional anti-cancer therapies and they are also safe as well as cost-effective. The aim of present study is to explore the anti-tumour effect of niclosamide in lung and breast cancer cell lines using biocompatible and biodegradable carrier where nanoparticles loaded with hydrophobic drug (niclosamide) were synthesized, characterized and applied as a stable anti-cancer agent. Niclosamide loaded chitosan nanoparticles (Nic-Chi Np's) of size approximately 100-120 nm in diameter containing hydrophobic anti-cancer drug, i.e. niclosamide, were prepared. Physico-chemical characterization confirms that the prepared nanoparticles are spherical, monodispersed and stable in aqueous systems. The therapeutic efficacy of Nic-Chi Np's was evaluated against breast cancer cell line (MCF-7) and human lung cancer cell line (A549). MTT assay reveals the cell viability of the prepared Nic-Chi Np's against A549 and MCF-7 cells and obtained an IC50 value of 8.75 µM and 7.5 µM, respectively. Acridine orange/ethidium bromide dual staining results verified the loss of the majority of the cells by apoptosis. Flow cytometer analysis quantified the generation of intracellular reactive oxygen species (ROS) and signified that exposure to a higher concentration (2 × IC50) of Nic-Chi Np's resulted in elevated ROS generation. Notably, Nic-Chi Np treatment showed more apoptosis and cell death in MCF-7 as compared to A549. Further, the remarkable induction of apoptosis by Nic-Chi Np's was confirmed by semi-quantitative reverse transcription polymerase chain reaction, scanning electron microscopy and cell-cycle analysis. Thus, Nic-Chi Np's may have a great potential even at low concentration for anti-cancer therapy and may replace or substitute more toxic anti-mitotic drugs in the near future.
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Affiliation(s)
- Saba Naqvi
- Nanobiotechnology Laboratory, Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India
| | - Shanid Mohiyuddin
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India
| | - P. Gopinath
- Nanobiotechnology Laboratory, Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India
- Author for correspondence: P. Gopinath e-mail: ;
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S Sibuyi NR, Thovhogi N, Gabuza KB, Meyer MD, Drah M, Onani MO, Skepu A, Madiehe AM, Meyer M. Peptide-functionalized nanoparticles for the selective induction of apoptosis in target cells. Nanomedicine (Lond) 2017. [PMID: 28635372 DOI: 10.2217/nnm-2017-0085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AIM The study developed a prohibitin (PHB) targeted nanotherapy for selective induction of apoptosis in target cells. METHODS Gold nanoparticles (AuNPs) were bifunctionalized with adipose homing and proapoptotic peptides. The efficacy and mode of cell death induced by the AuNPs were investigated in vitro on three cancer cell lines. RESULTS The antiproliferative activity of PHB-targeted bifunctionalized AuNPs was more pronounced on cells that express the PHB receptor, and demonstrated receptor-mediated targeting and selectivity. The bifunctionalized AuNPs induced cell death by apoptosis. CONCLUSION The PHB-targeted nanotherapy under study could potentially be used for treatment of diseases that are characterized by overexpression of PHB. As such, further investigations will be conducted in vivo.
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Affiliation(s)
- Nicole Remaliah S Sibuyi
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Ntevheleni Thovhogi
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Kwazikwakhe B Gabuza
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Miche D Meyer
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Mustafa Drah
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Martin O Onani
- Organometallics & Nanomaterials, Department of Chemistry, UWC, Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Amanda Skepu
- DST/Mintek NIC, Biolabels Unit, Advanced Materials Division, Mintek, Private Bag X3015, Randburg, 2125, Gauteng, South Africa
| | - Abram M Madiehe
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
| | - Mervin Meyer
- DST/Mintek Nanotechnology Innovation Centre (NIC), Biolabels Unit, Department of Biotechnology, University of the Western Cape (UWC), Private Bag X17, Bellville, 7535, Western Cape, South Africa
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Omoyeni OA, Hussein A, Meyer M, Green I, Iwuoha E. Pleiocarpa pycnantha leaves and its triterpenes induce apoptotic cell death in Caco-2 cells in vitro. Altern Ther Health Med 2015; 15:224. [PMID: 26169589 PMCID: PMC4499947 DOI: 10.1186/s12906-015-0767-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 07/06/2015] [Indexed: 12/28/2022]
Abstract
Background Recently, we reported that the crude fractions and pure triterpenes; ursolic acid (C1), 27-E and 27-Z p-coumaric esters of ursolic acid (C2, C3), together with a new triterpene 2,3-seco-taraxer-14-en-2,3-lactone [pycanocarpine (C4)] and its hydrolysed derivative - (2,3-seco-taraxen-4-hydroxy-14-en-2-oic acid) [pycanocarpene (C5)] from Pleiocarpa pycnantha leaves inhibit cell proliferation. However, there has not been any specific report on the use of Pleiocarpa pycnantha leaves and its constituents to kill colorectal adenocarcinoma cancer CaCo-2 cells. We performed in vitro study to evaluate the cytotoxic properties of the ethanolic extract of P. pycnanthaP, compounds C2 and C3. A preliminary study of the potential mechanisms were also undertaken. Methods Cell viability was measured by WST-1 assay. The Apoptosis level was evaluated by staining with APOPercentage™ dye and the induction of caspases 3/7 and 9 using Caspase-Glo® assays. Results The exposure of an ethanolic extract from the leaves of P. pycnantha (0.1–1000 μg/ml) and the isolated compounds C2 and C3 (6,25–100 μg/ml) to human colorectal cancer cells reduced the cell viability with an IC50 > 100, 40.9, 36.3 μg/ml for P, C2 and C3 respectively, after 24 h of incubation. The APOPercentageTM assay also showed a considerable increase in the percentage of apoptotic cells after 24 h; (25–38 % for P, 5–23 % for C2 and 6–47 % for C3). Caspase 3 was also activated which is a hallmark of apoptosis. Conclusion These findings suggest that the P. pycnantha and the isolated compounds induce cell apoptosis in human colorectal adenocarcinoma cells. A further study with other cell lines is also recommended.
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Saibu GM, Katerere DR, Rees DJG, Meyer M. In vitro cytotoxic and pro-apoptotic effects of water extracts of Tulbaghia violacea leaves and bulbs. JOURNAL OF ETHNOPHARMACOLOGY 2015; 164:203-209. [PMID: 25683299 DOI: 10.1016/j.jep.2015.01.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/25/2015] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Infusions of Tulbaghia violacea (wild garlic) in water are used in traditional medicine in Southern Africa to treat numerous diseases, including cancer. Several studies have previously demonstrated the cytotoxic activities of extracts of T. violacea in cultured cancer cells. Their findings support the potential anti-cancer properties of this plant. However, these studies made use of organic solvent extraction methods, while the traditional use of the plant involves the preparation of infusions in water. MATERIALS AND METHODS In the current study, we investigated the potential anti-cancer properties of infusions of T. violacea. We also performed a comparative study investigating the cytotoxic activities of T. violacea bulbs and leaves. A panel of four cancer cell lines (HepG2, MCF7, H157, and HT29) and one non-cancerous cell line (KMST6) was treated with the two extracts and the effects of the extracts on the growth of the cells were evaluated. We also investigated whether the growth inhibitory effects were associated with the induction of apoptosis and whether the mechanism of cell death is the result of oxidative stress and the activation of caspase-3. RESULT We found that extracts of the leaves and not the bulbs have growth inhibitory effects and that this is the result of the induction of apoptosis, which is associated with the production of Reactive Oxygen Species (ROS) and the activation of caspase-3. The leaf extract demonstrated variable selective toxicity towards the cancer lines. Although the extract also induced cell death in the non-cancerous cell line (KMST6), we found that the levels of toxicity were lower in this cell line. CONCLUSION this study confirms that infusions of T. violacea have potential anti-cancer activity and that this bioactivity is contained in the leaf extract. This study lends support to claims that this plant can be used to treat cancer.
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Affiliation(s)
- G M Saibu
- Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa
| | - D R Katerere
- Tshwane University of Technology, Faculty of Science, Department of Pharmaceutical Science, Building 4, Arcadia Campus, Pretoria 001, South Africa
| | - D J G Rees
- Agricultural Research Council, Private Bag X05, Onderstepoort, Pretoria 0110, South Africa
| | - M Meyer
- Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
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Mbita Z, Naicker S, Goetsch S, Dlamini Z. The association of RBBP6 variant 3 expressions with apoptosis in human immunodeficiency virus-associated nephropathy (HIVAN). Exp Mol Pathol 2015; 99:74-80. [PMID: 25910411 DOI: 10.1016/j.yexmp.2015.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/18/2015] [Indexed: 11/25/2022]
Abstract
South Africa has one of the highest HIV infection rates in the world. One of the complications of HIV infection is the development of HIV-associated nephropathy (HIVAN), which is characterized by deregulation in tubular epithelial apoptosis. The pathways that HIV-1 promotes in the pathogenesis of HIVAN remain less understood. There are many genes that have not been characterized in the pathogenesis of HIVAN. On the other hand, RBBP6 has been shown to play a role in both promoting and inhibiting apoptosis in human cancers. This study was aimed at determining an association between RBBP6 isoform 3 expression and the levels of apoptosis in HIVAN cases. HIVAN biopsy tissues from Johannesburg patients in South Africa were used in this study. These tissues were stained for RBBP6 expression and apoptosis levels using immunohistochemistry staining and TUNEL method respectively. Image analysis was used for quantitative analysis and GraphPad Version 4 was used for statistical analysis. High expression levels of RBBP6 were found in HIVAN cases (n=30) relative to the normal tissues (n=10). High apoptosis levels were also obtained in the HIVAN tissues. This direct association between RBBP6 expression and apoptosis levels suggests that RBBP6 may play a role in HIVAN pathogenesis. RBBP6 may then be targeted for both diagnostic and therapeutic strategies in HIVAN.
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Affiliation(s)
- Zukile Mbita
- Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Private Bag X 1106, Sovenga 0727, South Africa
| | - Sarala Naicker
- Faculty of Health Sciences, Wits Medical School, 7 York Road, Parktown, 2193, South Africa
| | - Stewart Goetsch
- Faculty of Health Sciences, Wits Medical School, 7 York Road, Parktown, 2193, South Africa
| | - Zodwa Dlamini
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban, 4031, South Africa.
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Traut-Johnstone T, Kanyanda S, Kriel FH, Viljoen T, Kotze PR, van Zyl WE, Coates J, Rees DJG, Meyer M, Hewer R, Williams DBG. Heteroditopic P,N ligands in gold(I) complexes: Synthesis, structure and cytotoxicity. J Inorg Biochem 2015; 145:108-20. [DOI: 10.1016/j.jinorgbio.2015.01.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 01/20/2015] [Accepted: 01/21/2015] [Indexed: 11/24/2022]
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Liu K, Liu PC, Liu R, Wu X. Dual AO/EB staining to detect apoptosis in osteosarcoma cells compared with flow cytometry. Med Sci Monit Basic Res 2015; 21:15-20. [PMID: 25664686 PMCID: PMC4332266 DOI: 10.12659/msmbr.893327] [Citation(s) in RCA: 414] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The aim of this study was to evaluate the ability of dual acridine orange/ethidium bromide (AO/EB) staining to detect tumor cell apoptosis. According to apoptosis-associated changes of cell membranes during the process of apoptosis, a clear distinction is made between normal cells, early and late apoptotic cells, and necrotic cells. MATERIAL AND METHODS We cultured human osteosarcoma cells with 30, 60, and 120 µg/ml kappa-selenocarrageenan. To assess the rates of cell proliferation and apoptosis, cells were fluorescently stained with acridine orange/ethidium bromide (AO/EB) or stained with propidium iodide (PI) and analyzed by flow cytometry. All experiments were repeated at least 3 times. RESULTS Normal tumor cells, early and late apoptotic cells, and necrotic cells were examined using fluorescent microscopy. Early-stage apoptotic cells were marked by crescent-shaped or granular yellow-green acridine orange nuclear staining. Late-stage apoptotic cells were marked with concentrated and asymmetrically localized orange nuclear ethidium bromide staining. Necrotic cells increased in volume and showed uneven orange-red fluorescence at their periphery. Cells appeared to be in the process of disintegrating. The percentage of apoptotic osteosarcoma cells detected by dual acridine orange/ethidium bromide (AO/EB) staining was not significantly different from that detected using flow cytometry (P>0.05). CONCLUSIONS Our results suggest that dual acridine orange/ethidium bromide staining is an economic and convenient method to detect apoptosis in tumor cells and to test tumor chemosensitivity compared with flow cytometry.
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Affiliation(s)
- Kuan Liu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China (mainland)
| | - Peng-cheng Liu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China (mainland)
| | - Run Liu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China (mainland)
| | - Xing Wu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China (mainland)
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Imino-phosphine palladium(II) and platinum(II) complexes: Synthesis, molecular structures and evaluation as antitumor agents. J Inorg Biochem 2013; 129:112-8. [DOI: 10.1016/j.jinorgbio.2013.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 11/19/2022]
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Motswainyana WM, Onani MO, Madiehe AM. Bis(ferrocenylimine)palladium(II) and platinum(II) complexes: Synthesis, molecular structures and evaluation as antitumor agents. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Zhang XL, Hu AB, Cui SZ, Wei HB. Thermotherapy enhances oxaliplatin-induced cytotoxicity in human colon carcinoma cells. World J Gastroenterol 2012; 18:646-53. [PMID: 22363135 PMCID: PMC3281221 DOI: 10.3748/wjg.v18.i7.646] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 09/28/2011] [Accepted: 10/05/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the synergistic effects of hyperthermia in oxaliplatin-induced cytotoxicity in human colon adenocarcinoma Lovo cells.
METHODS: The human colon adenocarcinoma cell line Lovo was obtained from Sun Yat-Sen University. Cells were sealed with parafilm and placed in a circulating water bath, and was maintained within 0.01 °C of the desired temperature (37 °C, 39 °C, 41 °C, 43 °C and 45 °C). Thermal therapy was given alone to the negative control group while oxaliplatin was administered to the treatment group at doses of 12.5 μg/mL and 50 μg/mL. Identification of morphological changes, 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry and Western blotting were used to investigate the effect of thermochemotherapy on human colon adenocarcinoma Lovo cells, including changes in the signal pathway related to apoptosis.
RESULTS: A temperature-dependent inhibition of cell growth was observed after oxaliplatin exposure, while a synergistic interaction was detected preferentially with sequential combination. Thermochemotherapy changed the morphology of Lovo cells, increased the inhibition rate of the Lovo cells (P < 0.05) and enhanced cellular population in the G0/G1 phase (16.7% ± 4.8 % in phase S plus 3.7% ± 2.4 % in phase G2/M, P < 0.05). Thermochemotherapy increased apoptosis through upregulating p53, Bax and downregulating Bcl-2. Protein levels were elevated in p53, Bax/Bcl-2 in thermochemotherapy group as compared with the control group (P < 0.05).
CONCLUSION: Thermochemotherapy may play an important role in apoptosis via the activation of p53, Bax and the repression of Bcl-2 in Lovo cells.
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Meningococcal outer membrane protein NhhA triggers apoptosis in macrophages. PLoS One 2012; 7:e29586. [PMID: 22238624 PMCID: PMC3251587 DOI: 10.1371/journal.pone.0029586] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 12/01/2011] [Indexed: 11/19/2022] Open
Abstract
Phagocytotic cells play a fundamental role in the defense against bacterial pathogens. One mechanism whereby bacteria evade phagocytosis is to produce factors that trigger apoptosis. Here we identify for the first time a meningococcal protein capable of inducing macrophage apoptosis. The conserved meningococcal outer membrane protein NhhA (Neisseria hia/hsf homologue A, also known as Hsf) mediates bacterial adhesion and interacts with extracellular matrix components heparan sulphate and laminin. Meningococci lacking NhhA fail to colonise nasal mucosa in a mouse model of meningococcal disease. We found that exposure of macrophages to NhhA resulted in a highly increased rate of apoptosis that proceeded through caspase activation. Exposure of macrophages to NhhA also led to iNOS induction and nitric oxide production. However, neither nitric oxide production nor TNF-α signaling was found to be a prerequisite for NhhA-induced apoptosis. Macrophages exposed to wildtype NhhA-expressing meningococci were also found to undergo apoptosis whereas NhhA-deficient meningococci had a markedly decreased capacity to induce macrophage apoptosis. These data provide new insights on the role of NhhA in meningococcal disease. NhhA-induced macrophage apoptosis could be a mechanism whereby meningococci evade immunoregulatory and phagocytotic actions of macrophages.
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Mbita Z, Meyer M, Skepu A, Hosie M, Rees J, Dlamini Z. De-regulation of the RBBP6 isoform 3/DWNN in human cancers. Mol Cell Biochem 2011; 362:249-62. [PMID: 22139301 DOI: 10.1007/s11010-011-1150-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 11/03/2011] [Indexed: 01/30/2023]
Abstract
Retinoblastoma binding protein 6 (RBBP6) is a nuclear protein, previously implicated in the regulation of cell cycle and apoptosis. The human RBBP6 gene codes for three protein isoforms and isoform 3 consists of the domain with no name domain only whilst the other two isoforms, 1 and 2 comprise of additional zinc, RING, retinoblastoma and p53 binding domains. In this study, the localization of RBBP6 using RBBP6 variant 3 mRNA-specific probe was performed to investigate the expression levels of the gene in different tumours and find a link between RBBP6 and human carcinogenesis. Using FISH, real-time PCR and Western blotting analysis our results show that RBBP6 isoform 3 is down-regulated in human cancers. RBBP6 isoform 3 knock-down resulted in reduced G2/M cell cycle arrest whilst its over-expression resulted in increased G2/M cell cycle arrest using propidium iodide DNA staining. The results further demonstrate that the RBBP6 isoform 3 may be the cell cycle regulator and involved in mitotic apoptosis not the isoform 1 as previously reported for mice. In conclusion, these findings suggest that RBBP6 isoform 3 is a cell cycle regulator and may be de-regulated in carcinogenesis.
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Affiliation(s)
- Zukile Mbita
- College of Agriculture and Environmental Science, University of South Africa, Florida Campus, Johannesburg, South Africa
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Sagar S, Green IR. Pro-apoptotic activities of novel synthetic quinones in human cancer cell lines. Cancer Lett 2009; 285:23-7. [DOI: 10.1016/j.canlet.2009.04.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 03/23/2009] [Accepted: 04/27/2009] [Indexed: 11/26/2022]
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