Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Oncogene volume  34, pages 5951–5959 (2015 )Cite this article

Glioblastomas (GBMs) are aggressive brain tumors that always recur after radiotherapy. Cystine, mainly provided by the system Xc− antiporter, is a requirement for glioma cell synthesis of glutathione (GSH) which has a critical role in scavenging free radicals, for example, after radiotherapy. Thus, we hypothesized that the Xc−-inhibitor sulfasalazine (SAS) could potentiate the efficacy of radiotherapy against gliomas. Here, we show that the catalytic subunit of system Xc−, xCT, was uniformly expressed in a panel of 30 human GBM biopsies. SAS treatment significantly reduced cystine uptake and GSH levels, whereas it significantly increased the levels of reactive oxygen species (ROS) in glioma cells in vitro. Furthermore, SAS and radiation synergistically increased DNA double-strand breaks and increased glioma cell death, whereas adding the antioxidant N-acetyl-L-cysteine (NAC) reversed cell death. Moreover, SAS and gamma knife radiosurgery (GKRS) synergistically prolonged survival in nude rats harboring human GBM xenografts, compared with controls or either treatment alone. In conclusion, SAS effectively blocks cystine uptake in glioma cells in vitro, leading to GSH depletion and increased ROS levels, DNA damage and cell death. Moreover, it potentiates the anti-tumor efficacy of GKRS in rats with human GBM xenografts, providing a survival benefit. Thus, SAS may have a role as a radiosensitizer to enhance the efficacy of current radiotherapies for glioma patients.

This is a preview of subscription content

Get full journal access for 1 year

All prices are NET prices. VAT will be added later in the checkout. Tax calculation will be finalised during checkout.

Get time limited or full article access on ReadCube.

All prices are NET prices.

Stupp R, Mason WP, van den Bent MJ, Weller M, Fisher B, Taphoorn MJ et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med 2005; 352: 987–996.

Cairns RA, Harris IS, Mak TW . Regulation of cancer cell metabolism. Nat Rev Cancer 2011; 11: 85–95.

Fruehauf JP, Meyskens FL Jr . Reactive oxygen species: a breath of life or death? Clin Cancer Res 2007; 13: 789–794.

Hayes JD, McMahon M . NRF2 and KEAP1 mutations: permanent activation of an adaptive response in cancer. Trends Biochem Sci 2009; 34: 176–188.

Lluis JM, Buricchi F, Chiarugi P, Morales A, Fernandez-Checa JC . Dual role of mitochondrial reactive oxygen species in hypoxia signaling: activation of nuclear factor-{kappa}B via c-SRC and oxidant-dependent cell death. Cancer Res 2007; 67: 7368–7377.

McDonald JT, Kim K, Norris AJ, Vlashi E, Phillips TM, Lagadec C et al. Ionizing radiation activates the Nrf2 antioxidant response. Cancer Res 2010; 70: 8886–8895.

Towner RA, Smith N, Saunders D, De Souza PC, Henry L, Lupu F et al. Combined molecular MRI and immuno-spin-trapping for in vivo detection of free radicals in orthotopic mouse GL261 gliomas. Biochim Biophys Acta 2013; 1832: 2153–2161.

Allalunis-Turner MJ, Day RS 3rd, McKean JD, Petruk KC, Allen PB, Aronyk KE et al. Glutathione levels and chemosensitizing effects of buthionine sulfoximine in human malignant glioma cells. J Neurooncol 1991; 11: 157–164.

Bannai S, Kitamura E . Transport interaction of L-cystine and L-glutamate in human diploid fibroblasts in culture. J Biol Chem 1980; 255: 2372–2376.

Sato H, Tamba M, Ishii T, Bannai S . Cloning and expression of a plasma membrane cystine/glutamate exchange transporter composed of two distinct proteins. J Biol Chem 1999; 274: 11455–11458.

Ye ZC, Rothstein JD, Sontheimer H . Compromised glutamate transport in human glioma cells: reduction-mislocalization of sodium-dependent glutamate transporters and enhanced activity of cystine-glutamate exchange. J Neurosci 1999; 19: 10767–10777.

Robert SM, Sontheimer H . Glutamate transporters in the biology of malignant gliomas. Cell Mol Life Sci 2014; 71: 1839–1854.

Lyons SA, Chung WJ, Weaver AK, Ogunrinu T, Sontheimer H . Autocrine glutamate signaling promotes glioma cell invasion. Cancer Res 2007; 67: 9463–9471.

Rothstein JD, Brem H . Excitotoxic destruction facilitates brain tumor growth. Nat Med 2001; 7: 994–995.

Buckingham SC, Campbell SL, Haas BR, Montana V, Robel S, Ogunrinu T et al. Glutamate release by primary brain tumors induces epileptic activity. Nat Med 2011; 17: 1269–1274.

Kim JY, Kanai Y, Chairoungdua A, Cha SH, Matsuo H, Kim DK et al. Human cystine/glutamate transporter: cDNA cloning and upregulation by oxidative stress in glioma cells. Biochim Biophys Acta 2001; 1512: 335–344.

Takeuchi S, Wada K, Toyooka T, Shinomiya N, Shimazaki H, Nakanishi K et al. Increased xCT expression correlates with tumor invasion and outcome in patients with glioblastomas. Neurosurgery 2013; 72: 33–41 discussion 41.

Neumann VC, Grindulis KA . Sulphasalazine in rheumatoid arthritis: an old drug revived. J R Soc Med 1984; 77: 169–172.

Dick AP, Grayson MJ, Carpenter RG, Petrie A et al. Controlled trial of sulphasalazine in the treatment of ulcerative colitis. Gut 1964; 5: 437–442.

Gout PW, Buckley AR, Simms CR, Bruchovsky N . Sulfasalazine, a potent suppressor of lymphoma growth by inhibition of the x(c)- cystine transporter: a new action for an old drug. Leukemia 2001; 15: 1633–1640.

Chung WJ, Lyons SA, Nelson GM, Hamza H, Gladson CL, Gillespie GY et al. Inhibition of cystine uptake disrupts the growth of primary brain tumors. J Neurosci 2005; 25: 7101–7110.

Ogunrinu TA, Sontheimer H . Hypoxia increases the dependence of glioma cells on glutathione. J Biol Chem 2010; 285: 37716–37724.

Salcman M . Survival in glioblastoma: historical perspective. Neurosurgery 1980; 7: 435–439.

Archibald YM, Lunn D, Ruttan LA, Macdonald DR, Del Maestro RF, Barr HW et al. Cognitive functioning in long-term survivors of high-grade glioma. J Neurosurg 1994; 80: 247–253.

Soffietti R, Kocher M, Abacioglu UM, Villa S, Fauchon F, Baumert BG et al. A European organisation for research and treatment of cancer phase III trial of adjuvant whole-brain radiotherapy versus observation in patients with one to three brain metastases from solid tumors after surgical resection or radiosurgery: quality-of-life results. J Clin Oncol 2013; 31: 65–72.

Skeie BS, Enger PØ, Brøgger J, Ganz JC, Thorsen F, Heggdal JI et al. gamma knife surgery versus reoperation for recurrent glioblastoma multiforme. World Neurosurg 2012; 78: 658–669.

Hsieh PC, Chandler JP, Bhangoo S, Panagiotopoulos K, Kalapurakal JA, Marymont MH et al. Adjuvant gamma knife stereotactic radiosurgery at the time of tumor progression potentially improves survival for patients with glioblastoma multiforme. Neurosurgery 2005; 57: 684–692 discussion 684-92.

Skeie BS, Wang J, Dodoo E, Heggdal JI, Grønli J, Sleire L et al. Gamma knife surgery as monotherapy with clinically relevant doses prolongs survival in a human GBM xenograft model. Biomed Res Int 2013; 2013: 139674.

Kato S, Negishi K, Mawatari K, Kuo CH . A mechanism for glutamate toxicity in the C6 glioma cells involving inhibition of cystine uptake leading to glutathione depletion. Neuroscience 1992; 48: 903–914.

Bump EA, Yu NY, Brown JM . Radiosensitization of hypoxic tumor cells by depletion of intracellular glutathione. Science 1982; 217: 544–545.

Narang VS, Pauletti GM, Gout PW, Buckley DJ, Buckley AR . Sulfasalazine-induced reduction of glutathione levels in breast cancer cells: enhancement of growth-inhibitory activity of Doxorubicin. Chemotherapy 2007; 53: 210–217.

Robe PA, Martin DH, Nguyen-Khac MT, Artesi M, Deprez M, Albert A et al. Early termination of ISRCTN45828668, a phase 1/2 prospective, randomized study of sulfasalazine for the treatment of progressing malignant gliomas in adults. BMC Cancer 2009; 9: 372.

Takeuchi S, Wada K, Nagatani K, Otani N, Osada H, Nawashiro H et al. Sulfasalazine and temozolomide with radiation therapy for newly diagnosed glioblastoma. Neurol India 2014; 62: 42–47.

Robe PA, Bentires-Alj M, Bonif M, Rogister B, Deprez M, Haddada H et al. In vitro and in vivo activity of the nuclear factor-kappaB inhibitor sulfasalazine in human glioblastomas. Clin Cancer Res 2004; 10: 5595–5603.

Akslen LA, Andersen KJ, Bjerkvig R . Characteristics of human and rat glioma cells grown in a defined medium. Anticancer Res 1988; 8: 797–803.

Bjerkvig R, Tønnesen A, Laerum OD, Backlund EO . Multicellular tumor spheroids from human gliomas maintained in organ culture. J Neurosurg 1990; 72: 463–475.

Sakariassen PO, Prestegarden L, Wang J, Skaftnesmo KO, Mahesparan R, Molthoff C et al. Angiogenesis-independent tumor growth mediated by stem-like cancer cells. Proc Natl Acad Sci USA 2006; 103: 16466–16471.

Wegener J, Keese CR, Giaever I . Electric cell-substrate impedance sensing (ECIS) as a noninvasive means to monitor the kinetics of cell spreading to artificial surfaces. Exp Cell Res 2000; 259: 158–166.

Wang J, Miletic H, Sakariassen PØ, Huszthy PC, Jacobsen H, Brekkå N et al. A reproducible brain tumour model established from human glioblastoma biopsies. BMC Cancer 2009; 9: 465.

Rey M, Valliccioni PA, Vial M, Porcheron D, Regis J, Kerlerian-le Goff L et al. Experimental radiosurgery in rats using gamma a ‘gamma knife’. Description of a stereotactic device for small laboratory animals. Neurochirurgie 1996; 42: 289–293.

J Wang and P Ø Enger: These authors contributed equally to this work.

Department of Biomedicine, Oncomatrix Research Lab, University of Bergen, Bergen, Norway

L Sleire, I A Netland, H E Førde, L Leiss, J Wang & P Ø Enger

Department of Clinical Medicine, K1, University of Bergen, Bergen, Norway

B S Skeie & P-H Pedersen

Department of Neurosurgery, Haukeland University Hospital, Bergen, Norway

B S Skeie, P-H Pedersen & P Ø Enger

Department of Neurosurgery, Karolinska University Hospital, Stockholm, Sweden

Department of Biomedicine, Proteomics Unit (PROBE), University of Bergen, Bergen, Norway

Neuro Clinic, Haukeland University Hospital, Bergen, Norway

Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

You can also search for this author in PubMed  Google Scholar

The authors declare no conflict of interest.

Supplementary Information accompanies this paper on the Oncogene website

Sleire, L., Skeie, B., Netland, I. et al. Drug repurposing: sulfasalazine sensitizes gliomas to gamma knife radiosurgery by blocking cystine uptake through system Xc−, leading to glutathione depletion. Oncogene 34, 5951–5959 (2015). https://doi.org/10.1038/onc.2015.60

DOI: https://doi.org/10.1038/onc.2015.60

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

Oncogene (Oncogene) ISSN 1476-5594 (online) ISSN 0950-9232 (print)