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Ling I, Skelton BW, Sobolev AN, Alias Y, Khor ZC, Raston CL. Effect of anions on the solid-state interplay of symmetric and unsymmetric phosphonium cations. NEW J CHEM 2020. [DOI: 10.1039/d0nj01975e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crystallographic studies of salts of quaternary phosphonium cations, tetraphenylphosphonium and benzyltriphenylphosphonium, reveal differences in size and shape of the phosphonium cations dominate the intermolecular packing with the cations self-associated through phenyl embraces.
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Affiliation(s)
- Irene Ling
- School of Science
- Monash University Malaysia
- Jalan Lagoon Selatan
- 47500 Bandar Sunway
- Malaysia
| | - Brian W. Skelton
- School of Molecular Sciences and CMCA, M310
- The University of Western Australia
- Perth
- Australia
| | - Alexandre N. Sobolev
- School of Molecular Sciences and CMCA, M310
- The University of Western Australia
- Perth
- Australia
| | - Yatimah Alias
- Chemistry Department
- Faculty of Science
- University of Malaya
- 50603 Kuala Lumpur
- Malaysia
| | - Zong Chin Khor
- School of Science
- Monash University Malaysia
- Jalan Lagoon Selatan
- 47500 Bandar Sunway
- Malaysia
| | - Colin L. Raston
- Flinders Institute for Nanoscale Science and Technology
- College of Science and Engineering
- Flinders University
- Bedford Park
- Australia
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2
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Arlauckas SP, Browning EA, Poptani H, Delikatny EJ. Imaging of cancer lipid metabolism in response to therapy. NMR IN BIOMEDICINE 2019; 32:e4070. [PMID: 31107583 DOI: 10.1002/nbm.4070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
Lipids represent a diverse array of molecules essential to the cell's structure, defense, energy, and communication. Lipid metabolism can often become dysregulated during tumor development. During cancer therapy, targeted inhibition of cell proliferation can likewise cause widespread and drastic changes in lipid composition. Molecular imaging techniques have been developed to monitor altered lipid profiles as a biomarker for cancer diagnosis and treatment response. For decades, MRS has been the dominant non-invasive technique for studying lipid metabolite levels. Recent insights into the oncogenic transformations driving changes in lipid metabolism have revealed new mechanisms and signaling molecules that can be exploited using optical imaging, mass spectrometry imaging, and positron emission tomography. These novel imaging modalities have provided researchers with a diverse toolbox to examine changes in lipids in response to a wide array of anticancer strategies including chemotherapy, radiation therapy, signal transduction inhibitors, gene therapy, immunotherapy, or a combination of these strategies. The understanding of lipid metabolism in response to cancer therapy continues to evolve as each therapeutic method emerges, and this review seeks to summarize the current field and areas of unmet needs.
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Affiliation(s)
- Sean Philip Arlauckas
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Systems Biology, Mass General Hospital, Boston, MA, USA
| | - Elizabeth Anne Browning
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Harish Poptani
- Department of Cellular and Molecular Physiology, Institute of Regenerative Medicine, University of Liverpool, Liverpool, UK
| | - Edward James Delikatny
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Kumar M, Arlauckas SP, Saksena S, Verma G, Ittyerah R, Pickup S, Popov AV, Delikatny EJ, Poptani H. Magnetic resonance spectroscopy for detection of choline kinase inhibition in the treatment of brain tumors. Mol Cancer Ther 2015; 14:899-908. [PMID: 25657334 DOI: 10.1158/1535-7163.mct-14-0775] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 01/27/2015] [Indexed: 11/16/2022]
Abstract
Abnormal choline metabolism is a hallmark of cancer and is associated with oncogenesis and tumor progression. Increased choline is consistently observed in both preclinical tumor models and in human brain tumors by proton magnetic resonance spectroscopy (MRS). Thus, inhibition of choline metabolism using specific choline kinase inhibitors such as MN58b may be a promising new strategy for treatment of brain tumors. We demonstrate the efficacy of MN58b in suppressing phosphocholine production in three brain tumor cell lines. In vivo MRS studies of rats with intracranial F98-derived brain tumors showed a significant decrease in tumor total choline concentration after treatment with MN58b. High-resolution MRS of tissue extracts confirmed that this decrease was due to a significant reduction in phosphocholine. Concomitantly, a significant increase in poly-unsaturated lipid resonances was also observed in treated tumors, indicating apoptotic cell death. MRI-based volume measurements demonstrated a significant growth arrest in the MN58b-treated tumors in comparison with saline-treated controls. Histologically, MN58b-treated tumors showed decreased cell density, as well as increased apoptotic cells. These results suggest that inhibition of choline kinase can be used as an adjuvant to chemotherapy in the treatment of brain tumors and that decreases in total choline observed by MRS can be used as an effective pharmacodynamic biomarker of treatment response.
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Affiliation(s)
- Manoj Kumar
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sean P Arlauckas
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sona Saksena
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Gaurav Verma
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ranjit Ittyerah
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stephen Pickup
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anatoliy V Popov
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Edward J Delikatny
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harish Poptani
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Department of Cellular and Molecular Physiology, Institute of Regenerative Medicine, University of Liverpool, Liverpool, United Kingdom.
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4
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Delikatny EJ, Chawla S, Leung DJ, Poptani H. MR-visible lipids and the tumor microenvironment. NMR IN BIOMEDICINE 2011; 24:592-611. [PMID: 21538631 PMCID: PMC3640643 DOI: 10.1002/nbm.1661] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 11/22/2010] [Accepted: 12/04/2010] [Indexed: 05/08/2023]
Abstract
MR-visible lipids or mobile lipids are defined as lipids that are observable using proton MRS in cells and tissues. These MR-visible lipids are composed of triglycerides and cholesterol esters that accumulate in neutral lipid droplets, where their MR visibility is conferred as a result of the increased molecular motion available in this unique physical environment. This review discusses the factors that lead to the biogenesis of MR-visible lipids in cancer cells and in other cell types, such as immune cells and fibroblasts. We focus on the accumulations of mobile lipids that are inducible in cultured cells by a number of stresses, including culture conditions, and in response to activating stimuli or apoptotic cell death induced by anticancer drugs. This is compared with animal tumor models, where increases in mobile lipids are observed in response to chemo- and radiotherapy, and to human tumors, where mobile lipids are observed predominantly in high-grade brain tumors and in regions of necrosis. Conducive conditions for mobile lipid formation in the tumor microenvironment are discussed, including low pH, oxygen availability and the presence of inflammatory cells. It is concluded that MR-visible lipids appear in cancer cells and human tumors as a stress response. Mobile lipids stored as neutral lipid droplets may play a role in the detoxification of the cell or act as an alternative energy source, especially in cancer cells, which often grow in ischemic/hypoxic environments. The role of MR-visible lipids in cancer diagnosis and the assessment of the treatment response in both animal models of cancer and human brain tumors is also discussed. Although technical limitations exist in the accurate detection of intratumoral mobile lipids, early increases in mobile lipids after therapeutic interventions may be useful as a potential biomarker for the assessment of treatment response in cancer.
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Affiliation(s)
- E James Delikatny
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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Corbin IR, Furth EE, Pickup S, Siegelman ES, Delikatny EJ. In vivo assessment of hepatic triglycerides in murine non-alcoholic fatty liver disease using magnetic resonance spectroscopy. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:757-63. [DOI: 10.1016/j.bbalip.2009.02.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 02/06/2009] [Accepted: 02/24/2009] [Indexed: 11/28/2022]
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Bundy JG, Iyer NG, Gentile MS, Hu DE, Kettunen M, Maia AT, Thorne NP, Brenton JD, Caldas C, Brindle KM. Metabolic consequences of p300 gene deletion in human colon cancer cells. Cancer Res 2006; 66:7606-14. [PMID: 16885360 DOI: 10.1158/0008-5472.can-05-2999] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Metabolite profiling using (1)H nuclear magnetic resonance (NMR) spectroscopy was used to investigate the metabolic changes associated with deletion of the gene for the transcriptional coactivator p300 in the human colon carcinoma cell line HCT116. Multivariate statistical methods were used to distinguish between metabolite patterns that were dependent on cell growth conditions and those that were specifically associated with loss of p300 function. In the absence of serum, wild-type cells showed slower growth, which was accompanied by a marked decrease in phosphocholine concentration, which was not observed in otherwise isogenic cell lines lacking p300. In the presence of serum, several metabolites were identified as being significantly different between the two cell types, including glutamate and glutamine, a nicotinamide-related compound and glycerophosphocholine (GPC). However, in the absence of serum, these metabolites, with the exception of GPC, were not significantly different, leading us to conclude that most of these changes were context dependent. Transcript profiling, using DNA microarrays, showed changes in the levels of transcripts for several enzymes involved in choline metabolism, which might explain the change in GPC concentration. Localized in vivo (1)H NMR measurements on the tumors formed following s.c. implantation of these cells into mice showed an increase in the intensity of the peak from choline-containing compounds in the p300(-) tumors. These data show that NMR-based metabolite profiling has sufficient sensitivity to identify the metabolic consequences of p300 gene deletion in tumor cells in vitro and in vivo.
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Affiliation(s)
- Jacob G Bundy
- Department of Biochemistry, Hutchison/Medical Research Council Research Centre, University of Cambridge, 80 Tennis Court Road, Cambridge, United Kingdom
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Lindskog M, Spenger C, Klason T, Jarvet J, Gräslund A, Johnsen JI, Ponthan F, Douglas L, Nordell B, Kogner P. Proton magnetic resonance spectroscopy in neuroblastoma: Current status, prospects and limitations. Cancer Lett 2005; 228:247-55. [PMID: 15946794 DOI: 10.1016/j.canlet.2004.12.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Accepted: 12/10/2004] [Indexed: 10/25/2022]
Abstract
Non-invasive biological information about residual neuroblastoma tumour tissue could allow treatment monitoring without the need for repeated biopsies. Magnetic resonance spectroscopy (MRS) can be performed with standard MR-scanners, providing specific biochemical information from selected tumour regions. By proton 1H-MRS, lipids, certain amino acids and lactate can be detected and their relative concentrations estimated in vivo. Using experimental models of neuroblastoma, we have described the potential of 1H-MRS for the prediction of tumour tissue viability and treatment response. Whereas viable neuroblastoma tissue is dominated by the choline 1H-MRS resonance, cell death as a consequence of spontaneous necrosis or successful treatment with chemotherapy, angiogenesis inhibitors, or NSAIDs is associated with decreased choline content. Therapy-induced neuroblastoma cell death is also associated with enhanced 1H-MRS resonances from mobile lipids and polyunsaturated fatty acids. The mobile lipid/choline ratio correlates significantly with cell death and based on the dynamics of this ratio tumour regression or continued growth (drug resistance) after chemotherapy can be predicted in vivo. The implications of these findings are discussed with focus on the potentials and limitations of introducing 1H-MRS for clinical assessment of treatment response in children with neuroblastoma. Biochemical monitoring of neuroblastoma with 1H-MRS could enable tailoring of individual therapy as well as provide early pharmacodynamic evaluation of novel therapeutic modalities.
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Affiliation(s)
- Magnus Lindskog
- Childhood Cancer Research Unit, Department of Woman and Child Health, Karolinska Institutet, Karolinska Hospital, S-17176 Stockholm, Sweden.
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Abstract
Magnetic resonance spectroscopy (MRS) has been used for more than two decades to interrogate metabolite distributions in living cells and tissues. Techniques have been developed that allow multiple spectra to be obtained simultaneously with individual volume elements as small as 1 uL of tissue (i.e., 1 x 1 x 1 mm(3)). The most common modern applications of in vivo MRS use endogenous signals from (1)H, (31)P, or (23)Na. Important contributions have also been made using exogenous compounds containing (19)F, (13)C, or (17)O. MRS has been used to investigate cardiac and skeletal muscle energetics, neurobiology, and cancer. This review focuses on the latter applications, with specific reference to the measurement of tissue choline, which has proven to be a tumor biomarker that is significantly affected by anticancer therapies.
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Affiliation(s)
- Robert J Gillies
- Arizona Cancer Center, 1515 Campbell Avenue, Tucson, AZ 85724-5024, USA.
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Milkevitch M, Shim H, Pilatus U, Pickup S, Wehrle JP, Samid D, Poptani H, Glickson JD, Delikatny EJ. Increases in NMR-visible lipid and glycerophosphocholine during phenylbutyrate-induced apoptosis in human prostate cancer cells. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1734:1-12. [PMID: 15866478 DOI: 10.1016/j.bbalip.2005.01.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 12/20/2004] [Accepted: 01/14/2005] [Indexed: 11/25/2022]
Abstract
DU145 human prostatic carcinoma cells were treated with the differentiating agents phenylacetate (PA) and phenylbutyrate (PB) and examined in perfused cultures by diffusion-weighted 1H and 31P nuclear magnetic resonance spectroscopy (NMR). PA and PB (10 mM) induced significant (>3-fold) time-dependent increases in the level of NMR-visible lipids and total choline in 1H spectra, and glycerophosphocholine levels in the 31P spectra, with the increases being greater for PB. These effects were accompanied by significant increases in cytoplasmic lipid droplets and intracellular lipid volume fraction as observed by morphometric analysis of Oil Red O-stained cells. PB treatment caused cell cycle arrest in the G1 phase and induction of apoptosis. In contrast, PA-treated DU145 cells showed an accumulation of cells in G2/M and no evidence of apoptosis. These results demonstrate that significant differences exist in the mechanism of PA and PB activity, although both compounds cause similar, but graded alterations in lipid metabolism. The simultaneous accumulation of mobile lipid and glycerophosphocholine suggests that PB and PA induce phospholipid catabolism via a phospholipase-mediated pathway. The mobile lipid accumulation following the induction of either apoptosis and cytostasis by related differentiating agents indicate that the presence of NMR-visible lipids may not be a specific event causally resulting from the induction of apoptosis.
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Affiliation(s)
- Matthew Milkevitch
- Department of Radiology, University of Pennsylvania School of Medicine, B6 Blockley Hall, 423 Guardian Drive, Philadelphia, PA 19104, USA
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Lindskog M, Spenger C, Jarvet J, Gräslund A, Kogner P. Predicting Resistance or Response to Chemotherapy by Proton Magnetic Resonance Spectroscopy in Neuroblastoma. J Natl Cancer Inst 2004; 96:1457-66. [PMID: 15467035 DOI: 10.1093/jnci/djh273] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND We previously showed that proton magnetic resonance spectroscopy (1H-MRS) enables estimation of neuroblastoma tumor viability. Here we investigated if 1H-MRS can predict response or resistance to chemotherapy in neuroblastoma. METHODS Neuroblastoma cell lines with various drug sensitivities were treated with cytotoxic drugs (cisplatin, etoposide, and irinotecan) and examined by 1H-MRS. Viability was assessed by trypan blue staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Nude rats carrying drug-sensitive or drug-resistant neuroblastoma xenografts were treated for 4 days with irinotecan (n = 11) or saline (n = 11) and were examined with 1H-MRS at 4.7 T before and during treatment. The Wilcoxon matched-pairs test was used to test statistical significance of difference within treatment groups. Independent groups were compared using the Mann-Whitney U test. Correlation was assessed with Spearman's rank correlation. All statistical tests were two-sided. RESULTS Cytotoxic drug treatment of drug-sensitive SH-SY5Y neuroblastoma cells resulted in increased methylene and polyunsaturated fatty acid resonances and decreased choline resonance. The methylene/choline ratio correlated with cell death (r(s) = .94, P<.001) and was increased in cisplatin-treated drug-sensitive (SH-SY5Y, IMR-32) but not drug-resistant [SK-N-BE2, SK-N-FI, SK-N-AS] cell lines. No changes were observed in SK-N-BE2 cells treated with irinotecan or cisplatin, whereas circumvention of the resistance by arsenic trioxide treatment led to lipid accumulation and choline depletion. Irinotecan therapy of rats carrying drug-sensitive xenografts caused the methylene/choline ratio of tumors to increase eightfold after 3 days (95% confidence interval [CI] = fivefold to 12-fold; P = .005 compared with pretreatment spectra at day 0) and caused tumors to regress statistically significantly on day 10 compared with pretreatment volume on day 0 (difference = -60%, 95% CI = -12% to -100%, n = 6; P = .012). The methylene/choline ratio of nonregressing drug-resistant xenografts was unaffected. No differences were observed after saline treatment. CONCLUSIONS Response or resistance to chemotherapy is accurately predicted by 1H-MRS in experimental neuroblastoma models in vivo.
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Affiliation(s)
- Magnus Lindskog
- Childhood Cancer Research Unit, Department of Woman and Child Health, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden.
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Ferretti A, Knijn A, Raggi C, Sargiacomo M. High-resolution proton NMR measures mobile lipids associated with Triton-resistant membrane domains in haematopoietic K562 cells lacking or expressing caveolin-1. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2003; 32:83-95. [PMID: 12734696 DOI: 10.1007/s00249-002-0273-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2002] [Revised: 11/06/2002] [Accepted: 11/20/2002] [Indexed: 10/25/2022]
Abstract
High-resolution proton NMR spectra of intact tumour cells generally exhibit intense signals due to isotropically mobile lipids (MLs) of still uncertain nature and origin. NMR studies performed on intact wild-type and caveolin-1-infected haematopoietic K562 cells showed that, under our experimental conditions, part of the ML signals are due to lipid complexes resistant to extraction in Triton X-100 at 4 degrees C. This evidence suggests that a portion of NMR-visible lipid structures are compatible with Triton-resistant membrane rafts and therefore biophysically distinct from NMR-visible Triton-soluble lipid bodies. Similarly to lipid rafts and caveolae, the organization of the Triton-insoluble ML domains could be compromised by treatment with beta-octylglucoside or methyl-beta-cyclodextrin. Exposure to exogenous sphingomyelinase caused an increase in ML NMR visibility, indicating the possible involvement of ceramides in ML formation. The mobility of these lipids was found to be temperature sensitive, suggesting a transition in cells going from 4 degrees C to 25-37 degrees C. These new results are here discussed in the light of possible contributions of plasma membrane microdomains to NMR-visible ML signals.
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Affiliation(s)
- A Ferretti
- Laboratory of Cell Biology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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Delikatny EJ, van Holst Pellekaan CJ, King NJ. Autologous lymphocyte-monocyte co-culture increases NMR-visible and cytoplasmic lipids in the absence of increased markers of lymphocyte activation. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1533:243-54. [PMID: 11731334 DOI: 10.1016/s1388-1981(01)00157-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Alterations in nuclear magnetic resonance (NMR)-visible lipid, morphometric lipid volume fraction, distribution of subcellular lipid droplets and activation antigen expression were examined in human peripheral blood lymphocytes, activated using phorbol myristate acetate (PMA) and ionomycin or by co-culture with autologous monocytes. PMA/Ionomycin treatment caused significant time-dependent increases in mobile lipid and in oil red O-positive lipid droplets that were accompanied by lymphocyte proliferation and increases in activation antigens, CD25, CD69 and CD71. Co-culture of lymphocytes and monocytes also induced significant increases in NMR-visible lipid signals and cytoplasmic lipid droplets, but in contrast, no correspondent increases in activation antigens were observed. Strong correlations were observed between the intensity of the NMR signal and the percentage of total cells containing lipid droplets (r=0.95) and the morphometric lymphocyte lipid volume fraction (r=0.80), indicating that the droplets were the source of the mobile lipid signal. Lipid droplets in PMA/Ionomycin-treated cells were evenly distributed throughout the population, but in co-cultures, only lymphocytes in close proximity to monocytes with lipid droplets contained oil red O-positive lipid. This data shows that the NMR-visible mobile lipid signal observed in lymphocytes co-cultured with monocytes is not directly dependent on either proliferation or the upregulation of activation antigens, similar to the previously observed response of T cells exposed to antibodies to the T cell receptor.
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Affiliation(s)
- E J Delikatny
- Department of Cancer Medicine, The University of Sydney, Australia.
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Cooper WA, Bartier WA, Rideout DC, Delikatny EJ. 1H NMR visible lipids are induced by phosphonium salts and 5-fluorouracil in human breast cancer cells. Magn Reson Med 2001; 45:1001-10. [PMID: 11378877 DOI: 10.1002/mrm.1133] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cationic lipophilic phosphonium salts (CLPS) selectively accumulate in the mitochondria of neoplastic cells and inhibit mitochondrial function. The effects of the CLPS p-(triphenylphosphoniummethyl) benzaldehyde chloride (drug A), and [4-(hydrazinocarboxy)-1-butyl] tris-(4-dimethylaminophenyl) phosphonium chloride (drug B), on human breast cells of differing biological properties were assessed using growth inhibition assays and 1H NMR. Drug A and, to a lesser extent, drug B demonstrated selective growth inhibition of the highly tumorigenic DU4475 breast carcinoma cell line compared to the transformed HBL-100 human breast cell line. However, in contrast to previous studies using other cell lines, no synergistic activity was found when the drugs were used in combination. 1H NMR demonstrated significant increases in mobile lipid acyl chain resonances in both cell lines treated with cytotoxic doses (IC50, 48 h) of the drugs used either alone or in combination. Two-dimensional NMR revealed accompanying decreases in phosphocholine/Lys levels in HBL-100 cells treated with A, B, or a 1:1 combination A+B at the IC50, and in DU4475 cells treated with drug A (IC50). This was accompanied by significant increases in cho/Lys ratios with IC50 A or combination A+B treatment. Similar spectra were observed in cells treated with 5-fluorouracil but not methotrexate, indicating that mobile lipid accumulation is a general but not universal response to cytotoxic insult.
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Affiliation(s)
- W A Cooper
- Department of Cancer Medicine, University of Sydney, Sydney, Australia
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14
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Le Moyec L, Legrand O, Larue V, Kawakami M, Marie JP, Calvo F, Hantz E, Taillandier E. Magnetic resonance spectroscopy of cellular lipid extracts from sensitive, resistant and reverting K562 cells and flow cytometry for investigating the P-glycoprotein function in resistance reversion. NMR IN BIOMEDICINE 2000; 13:92-101. [PMID: 10797637 DOI: 10.1002/(sici)1099-1492(200004)13:2<92::aid-nbm615>3.0.co;2-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The proton NMR spectra of K562 cells contain resonances of lipids. When these cells acquire multidrug resistance phenotype, the NMR lipid signals are modified and partially recovered when the resistance is reversed. The goals of the present study are to elucidate the mechanism of the resistance phenotype reversion and to investigate the possible origin of lipid signals detected in whole cells with proton NMR spectroscopy. Therefore, the K562 drug-sensitive cell line, its adriamycin resistant counterpart and two reverting derivates, obtained by verapamil treatment and long term culture in drug-free medium, were used in this study. The P-glycoprotein (P-gp) pump function was measured by flow cytometry and lipids were extracted to be analysed by proton and phosphorus spectroscopy. The phenotype reversion is due to the decrease of the P-gp function and an increased entrance of anthracycline drug when compared with the resistant cells. The spectra obtained on extracts showed no modification of the fatty acid composition and of the ratio of total cholesterol to fatty acid content. A different phospholipid composition in sensitive and resistant cells was found, but the reversion of resistance did not produce a recovery of these lipids. Thus, the lipid NMR spectra of extracts could not explain the spectral modifications observed on whole cells, in relation to acquiring and reverting drug resistance. These results are in favour of a different lipid organization or of localization within the cell.
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Affiliation(s)
- L Le Moyec
- Laboratoire CSSB, UPRES A 7031, UFR SMBH, 74 rue Marcel Cachin, 93017 Bobigny, France
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Viola A, Lutz NW, Maroc C, Chabannon C, Julliard M, Cozzone PJ. Metabolic effects of photodynamically induced apoptosis in an erythroleukemic cell line. A (31)P NMR spectroscopic study of Victoria-Blue-BO-sensitized TF-1 cells. Int J Cancer 2000; 85:733-9. [PMID: 10699957 DOI: 10.1002/(sici)1097-0215(20000301)85:5<733::aid-ijc22>3.0.co;2-c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Victoria Blue BO (VB BO) is a new and promising photosensitizer currently being evaluated for photodynamic therapy (PDT). Its photochemical processes are mediated by oxygen radicals, but do not involve singlet oxygen. We used (31)P NMR spectroscopy of VB-BO sensitized TF-1 leukemic cells to gain further insight into the biochemical mechanisms underlying PDT-induced cell death. Sham-treatment experiments were performed to evaluate the effects of this photosensitizer in the absence of light irradiation. Significant metabolic differences were detected for TF-1 cells incubated with VB BO but not exposed to light, as compared with native cells (controls). These changes include reductions in phosphocreatine, UDP-hexose and phosphodiester levels (as percentage of total phosphate) and slightly reduced intracellular pH. Complete phosphocreatine depletion, significant acidification and concomitant inorganic-phosphate accumulation were observed for TF-1 cells irradiated after incubation with VB BO. Moreover, significant changes in phospholipid metabolites, i.e., accumulation of cytidine 5'-diphosphate choline and a decrease in phosphodiester levels, were observed for PDT-treated vs. sham-treated cells. Perturbations of phospholipid metabolism may be involved in programmed cell death, and the detection of a characteristic DNA ladder pattern by gel electrophoresis confirmed the existence of apoptosis in PDT-treated TF-1 cells.
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Affiliation(s)
- A Viola
- Laboratoire AM3, ESA-CNRS 6009, Faculté Saint-Jérôme, Marseille, France
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