{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T06:02:20Z","timestamp":1792648940056,"version":"4.5.0"},"reference-count":43,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,3,4]],"date-time":"2021-03-04T00:00:00Z","timestamp":1614816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>(1) Background: Despite progress in surgery and radio-chemotherapy of glioblastoma (GB), the prognosis remains very poor. GB cells exhibit a preference for hypoxia to maintain their tumor-forming capacity. Enhancing oxidative phosphorylation\u2014known as the anti-Warburg effect\u2014with cyclic AMP activators has been demonstrated to drive GB cells from proliferation to differentiation thereby reducing tumor growth in a cell culture approach. Here we re-evaluate this treatment in a more clinically relevant model. (2) Methods: The effect of treatment with dibutyryl cyclic AMP (dbcAMP, 1 mM) and the cAMP activator forskolin (50\u00b5M) was assessed in a GB cell line (U87GFP+, 104 cells) co-cultured with mouse organotypic brain slices providing architecture and biochemical properties of normal brain tissue. Cell viability was determined by propidium-iodide, and gross metabolic effects were excluded in the extracellular medium. Tumor growth was quantified in terms of area, volume, and invasion at the start of culture, 48 h, 7 days, and 14 days after treatment. (3) Results: The tumor area was significantly reduced following dbcAMP or forskolin treatment (F2,249 = 5.968, p = 0.0029). 3D volumetric quantification utilizing two-photon fluorescence microscopy revealed that the treated tumors maintained a spheric shape while the untreated controls exhibited the GB typical invasive growth pattern. (4) Conclusions: Our data demonstrate that treatment with a cAMP analog\/activator reduces GB growth and invasion.<\/jats:p>","DOI":"10.3390\/cells10030556","type":"journal-article","created":{"date-parts":[[2021,3,4]],"date-time":"2021-03-04T21:58:07Z","timestamp":1614895087000},"page":"556","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Treatment with Cyclic AMP Activators Reduces Glioblastoma Growth and Invasion as Assessed by Two-Photon Microscopy"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4572-3600","authenticated-orcid":false,"given":"Krista Min\u00e9ia","family":"Wartchow","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Friedrich-Alexander University, 91054 Erlangen, Germany"},{"name":"Department of Biochemistry, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benjamin","family":"Schmid","sequence":"additional","affiliation":[{"name":"Institute of Optical Imaging Erlangen, 91054 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philipp","family":"Tripal","sequence":"additional","affiliation":[{"name":"Institute of Optical Imaging Erlangen, 91054 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8348-2620","authenticated-orcid":false,"given":"Andreas","family":"Stadlbauer","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Friedrich-Alexander University, 91054 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Buchfelder","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Friedrich-Alexander University, 91054 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8430-5650","authenticated-orcid":false,"given":"Carlos-Alberto","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Kleindienst","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Friedrich-Alexander University, 91054 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"863","DOI":"10.21037\/apm-20-640","article-title":"Overview of prognostic factors in adult gliomas","volume":"10","author":"Sharma","year":"2020","journal-title":"Ann. Palliat. Med."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"De Vleeschouwer, S. (2017). Surgical Management of Glioblastoma. Glioblastoma, Codon Publications.","DOI":"10.15586\/codon.glioblastoma.2017"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1056\/NEJMoa043330","article-title":"Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma","volume":"352","author":"Stupp","year":"2005","journal-title":"N. Engl. J. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1038\/nrc3038","article-title":"Otto Warburg\u2019s contributions to current concepts of cancer metabolism","volume":"11","author":"Koppenol","year":"2011","journal-title":"Nat. Rev. Cancer"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1038\/nrc2981","article-title":"Regulation of cancer cell metabolism","volume":"11","author":"Cairns","year":"2011","journal-title":"Nat. Rev. Cancer"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1126\/science.1160809","article-title":"Understanding the Warburg effect: The metabolic requirements of cell proliferation","volume":"324","author":"Cantley","year":"2009","journal-title":"Science"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1016\/j.celrep.2016.12.037","article-title":"The Anti-Warburg Effect Elicited by the cAMP-PGC1alpha Pathway Drives Differentiation of Glioblastoma Cells into Astrocytes","volume":"18","author":"Xing","year":"2017","journal-title":"Cell Rep."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/S0163-7258(01)00132-2","article-title":"Differentiation therapy of human cancer: Basic science and clinical applications","volume":"90","author":"Leszczyniecka","year":"2001","journal-title":"Pharmacol. Ther."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3495","DOI":"10.1073\/pnas.1222863110","article-title":"8-CPT-cAMP\/all-trans retinoic acid targets t(11;17) acute promyelocytic leukemia through enhanced cell differentiation and PLZF\/RARalpha degradation","volume":"110","author":"Jiao","year":"2013","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_10","unstructured":"Patra, C., Foster, K., Corley, J.E., Dimri, M., and Brady, M.F. (2020). Biochemistry, cAMP, StatPearls."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"5717","DOI":"10.1158\/0008-5472.CAN-09-3769","article-title":"Cyclic AMP suppression is sufficient to induce gliomagenesis in a mouse model of neurofibromatosis-1","volume":"70","author":"Warrington","year":"2010","journal-title":"Cancer Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1158\/0008-5472.CAN-06-2762","article-title":"Blocking CXCR4-mediated cyclic AMP suppression inhibits brain tumor growth in vivo","volume":"67","author":"Yang","year":"2007","journal-title":"Cancer Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.neuroscience.2015.07.086","article-title":"Organotypic brain slice cultures: A review","volume":"305","author":"Humpel","year":"2015","journal-title":"Neuroscience"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Marques-Torrejon, M.A., Gangoso, E., and Pollard, S.M. (2018). Modelling glioblastoma tumour-host cell interactions using adult brain organotypic slice co-culture. Dis. Model. Mech., 11.","DOI":"10.1242\/dmm.031435"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2635","DOI":"10.1002\/cam4.1174","article-title":"Organotypic brain explant culture as a drug evaluation system for malignant brain tumors","volume":"6","author":"Minami","year":"2017","journal-title":"Cancer Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"513","DOI":"10.1006\/bbrc.2000.2332","article-title":"Quantitative analysis of glioma cell invasion by confocal laser scanning microscopy in a novel brain slice model","volume":"269","author":"Matsumura","year":"2000","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1838","DOI":"10.18632\/oncotarget.6550","article-title":"A versatile ex vivo technique for assaying tumor angiogenesis and microglia in the brain","volume":"7","author":"Ghoochani","year":"2016","journal-title":"Oncotarget"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1523\/JNEUROSCI.22-03-00612.2002","article-title":"Neurogenesis in the adult brain","volume":"22","author":"Gage","year":"2002","journal-title":"J. Neurosci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1038\/nmeth.2019","article-title":"Fiji: An open-source platform for biological-image analysis","volume":"9","author":"Schindelin","year":"2012","journal-title":"Nat. Methods"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1038\/s41592-019-0359-1","article-title":"3Dscript: Animating 3D\/4D microscopy data using a natural-language-based syntax","volume":"16","author":"Schmid","year":"2019","journal-title":"Nat. Methods"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3838","DOI":"10.1200\/JCO.2010.30.0582","article-title":"Scale to predict survival after surgery for recurrent glioblastoma multiforme","volume":"28","author":"Park","year":"2010","journal-title":"J. Clin. Oncol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1016\/S1470-2045(09)70025-7","article-title":"Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase III study: 5-year analysis of the EORTC-NCIC trial","volume":"10","author":"Stupp","year":"2009","journal-title":"Lancet. Oncol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"763","DOI":"10.1007\/s00401-013-1173-y","article-title":"Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells","volume":"126","author":"Kathagen","year":"2013","journal-title":"Acta Neuropathol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"983","DOI":"10.1093\/brain\/awq042","article-title":"A hypoxic niche regulates glioblastoma stem cells through hypoxia inducible factor 2 alpha","volume":"133","author":"Seidel","year":"2010","journal-title":"Brain J. Neurol."},{"key":"ref_25","first-page":"5813","article-title":"Intra-tumoral treatment with oxygen-ozone in glioblastoma: A systematic literature search and results of a case series","volume":"16","author":"Megele","year":"2018","journal-title":"Oncol. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Vollmann-Zwerenz, A., Leidgens, V., Feliciello, G., Klein, C.A., and Hau, P. (2020). Tumor Cell Invasion in Glioblastoma. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21061932"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1038\/sj.mp.4002072","article-title":"Beta-amyloid expression, release and extracellular deposition in aged rat brain slices","volume":"13","author":"Marksteiner","year":"2008","journal-title":"Mol. Psychiatry"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.pneurobio.2009.01.002","article-title":"Cell death and proliferation in acute slices and organotypic cultures of mammalian CNS","volume":"88","author":"Lossi","year":"2009","journal-title":"Prog. Neurobiol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Clark, M.J., Homer, N., O\u2019Connor, B.D., Chen, Z., Eskin, A., Lee, H., Merriman, B., and Nelson, S.F. (2010). U87MG decoded: The genomic sequence of a cytogenetically aberrant human cancer cell line. PLoS Genet., 6, Correction in 2018, 14, e1007392.","DOI":"10.1371\/journal.pgen.1007392"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"354re353","DOI":"10.1126\/scitranslmed.aaf6853","article-title":"Origin of the U87MG glioma cell line: Good news and bad news","volume":"8","author":"Allen","year":"2016","journal-title":"Sci. Transl. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.canlet.2008.02.010","article-title":"Isolation and characterization of cancer stem cells from a human glioblastoma cell line U87","volume":"265","author":"Yu","year":"2008","journal-title":"Cancer Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2347","DOI":"10.1111\/j.1460-9568.2005.04067.x","article-title":"Interleukin-1beta exacerbates and interleukin-1 receptor antagonist attenuates neuronal injury and microglial activation after excitotoxic damage in organotypic hippocampal slice cultures","volume":"21","author":"Hailer","year":"2005","journal-title":"Eur. J. Neurosci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1284","DOI":"10.1111\/j.1471-4159.2004.02812.x","article-title":"S100B protein is released by in vitro trauma and reduces delayed neuronal injury","volume":"91","author":"Willoughby","year":"2004","journal-title":"J. Neurochem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1038\/sj.jcbfm.9600544","article-title":"Acute plasmalemma permeability and protracted clearance of injured cells after controlled cortical impact in mice","volume":"28","author":"Whalen","year":"2008","journal-title":"J. Cereb. Blood Flow Metab."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3130","DOI":"10.1523\/JNEUROSCI.5119-05.2006","article-title":"Mechanoporation induced by diffuse traumatic brain injury: An irreversible or reversible response to injury?","volume":"26","author":"Farkas","year":"2006","journal-title":"J. Neurosci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1038\/nprot.2006.169","article-title":"Long-term live imaging of neuronal circuits in organotypic hippocampal slice cultures","volume":"1","author":"Gogolla","year":"2006","journal-title":"Nat. Protoc."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/0165-0270(91)90141-L","article-title":"In vitro microdialysis: A novel technique for stimulated neurotransmitter release measurements","volume":"36","author":"Bradberry","year":"1991","journal-title":"J. Neurosci. Methods"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1046\/j.1471-4159.2003.01673.x","article-title":"Quantitative on-line monitoring of hippocampus glucose and lactate metabolism in organotypic cultures using biosensor technology","volume":"85","author":"Gramsbergen","year":"2003","journal-title":"J. Neurochem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.biocel.2017.05.022","article-title":"Cell biology-metabolic crosstalk in glioma","volume":"89","author":"Colquhoun","year":"2017","journal-title":"Int. J. Biochem. Cell Biol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"e1600200","DOI":"10.1126\/sciadv.1600200","article-title":"Fundamentals of cancer metabolism","volume":"2","author":"DeBerardinis","year":"2016","journal-title":"Sci. Adv."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1136\/jnnp.64.4.486","article-title":"Interstitial glycerol as a marker for membrane phospholipid degradation in the acutely injured human brain","volume":"64","author":"Hillered","year":"1998","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1023\/A:1022106910017","article-title":"Baseline levels of glucose metabolites, glutamate and glycerol in malignant glioma assessed by stereotactic microdialysis","volume":"61","author":"Roslin","year":"2003","journal-title":"J. Neuro Oncol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"281","DOI":"10.3892\/mco.2013.65","article-title":"Targeted activation of PKA and Epac promotes glioblastoma regression in vitro","volume":"1","author":"Sugimoto","year":"2013","journal-title":"Mol. Clin. Oncol."}],"container-title":["Cells"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4409\/10\/3\/556\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:32:50Z","timestamp":1760160770000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4409\/10\/3\/556"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,4]]},"references-count":43,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,3]]}},"alternative-id":["cells10030556"],"URL":"https:\/\/doi.org\/10.3390\/cells10030556","relation":{},"ISSN":["2073-4409"],"issn-type":[{"value":"2073-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,4]]}}}