TY - JOUR A1 - Jarius, Sven A1 - Ruprecht, Klemens A1 - Kleiter, Ingo A1 - Borisow, Nadja A1 - Asgari, Nasrin A1 - Pitarokoili, Kalliopi A1 - Pache, Florence A1 - Stich, Oliver A1 - Beume, Lena-Alexandra A1 - Hümmert, Martin W. A1 - Ringelstein, Marius A1 - Trebst, Corinna A1 - Winkelmann, Alexander A1 - Schwarz, Alexander A1 - Buttmann, Mathias A1 - Zimmermann, Hanna A1 - Kuchling, Joseph A1 - Franciotta, Diego A1 - Capobianco, Marco A1 - Siebert, Eberhard A1 - Lukas, Carsten A1 - Korporal-Kuhnke, Mirjam A1 - Haas, Jürgen A1 - Fechner, Kai A1 - Brandt, Alexander U. A1 - Schanda, Kathrin A1 - Aktas, Orhan A1 - Paul, Friedemann A1 - Reindl, Markus A1 - Wildemann, Brigitte T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 2: Epidemiology, clinical presentation, radiological and laboratory features, treatment responses, and long-term outcome JF - Journal of Neuroinflammation N2 - Background A subset of patients with neuromyelitis optica spectrum disorders (NMOSD) has been shown to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOG-IgG). Objective To describe the epidemiological, clinical, radiological, cerebrospinal fluid (CSF), and electrophysiological features of a large cohort of MOG-IgG-positive patients with optic neuritis (ON) and/or myelitis (n = 50) as well as attack and long-term treatment outcomes. Methods Retrospective multicenter study. Results The sex ratio was 1:2.8 (m:f). Median age at onset was 31 years (range 6-70). The disease followed a multiphasic course in 80% (median time-to-first-relapse 5 months; annualized relapse rate 0.92) and resulted in significant disability in 40% (mean follow-up 75 ± 46.5 months), with severe visual impairment or functional blindness (36%) and markedly impaired ambulation due to paresis or ataxia (25%) as the most common long-term sequelae. Functional blindness in one or both eyes was noted during at least one ON attack in around 70%. Perioptic enhancement was present in several patients. Besides acute tetra-/paraparesis, dysesthesia and pain were common in acute myelitis (70%). Longitudinally extensive spinal cord lesions were frequent, but short lesions occurred at least once in 44%. Fourty-one percent had a history of simultaneous ON and myelitis. Clinical or radiological involvement of the brain, brainstem, or cerebellum was present in 50%; extra-opticospinal symptoms included intractable nausea and vomiting and respiratory insufficiency (fatal in one). CSF pleocytosis (partly neutrophilic) was present in 70%, oligoclonal bands in only 13%, and blood-CSF-barrier dysfunction in 32%. Intravenous methylprednisolone (IVMP) and long-term immunosuppression were often effective; however, treatment failure leading to rapid accumulation of disability was noted in many patients as well as flare-ups after steroid withdrawal. Full recovery was achieved by plasma exchange in some cases, including after IVMP failure. Breakthrough attacks under azathioprine were linked to the drug-specific latency period and a lack of cotreatment with oral steroids. Methotrexate was effective in 5/6 patients. Interferon-beta was associated with ongoing or increasing disease activity. Rituximab and ofatumumab were effective in some patients. However, treatment with rituximab was followed by early relapses in several cases; end-of-dose relapses occurred 9-12 months after the first infusion. Coexisting autoimmunity was rare (9%). Wingerchuk’s 2006 and 2015 criteria for NMO(SD) and Barkhof and McDonald criteria for multiple sclerosis (MS) were met by 28%, 32%, 15%, 33%, respectively; MS had been suspected in 36%. Disease onset or relapses were preceded by infection, vaccination, or pregnancy/delivery in several cases. Conclusion Our findings from a predominantly Caucasian cohort strongly argue against the concept of MOG-IgG denoting a mild and usually monophasic variant of NMOSD. The predominantly relapsing and often severe disease course and the short median time to second attack support the use of prophylactic long-term treatments in patients with MOG-IgG-positive ON and/or myelitis. KW - Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) KW - Aquaporin-4 antibodies (AQP4-IgG, NMO-IgG) KW - Optic neuritis KW - Transverse myelitis KW - Longitudinally extensive transverse myelitis KW - Magnetic resonance imaging KW - Autoantibodies KW - Neuromyelitis optica spectrum disorders (NMOSD) KW - Cerebrospinal fluid KW - Oligoclonal bands KW - Electrophysiology KW - Evoked potentials KW - Treatment KW - Therapy KW - Methotrexate KW - Azathioprine KW - Rituximab KW - Ofatumumab KW - Interferon beta KW - Glatiramer acetate KW - Natalizumab KW - Outcome KW - Pregnancy KW - Infections KW - Vaccination KW - Multiple sclerosis KW - Barkhof criteria KW - McDonald criteria KW - Wingerchuk criteria 2006 and 2015 KW - IPND criteria KW - International consensus diagnostic criteria for neuromyelitis optica spectrum disorders Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165570 VL - 13 IS - 280 ER - TY - JOUR A1 - Jarius, Sven A1 - Ruprecht, Klemens A1 - Kleiter, Ingo A1 - Borisow, Nadja A1 - Asgari, Nasrin A1 - Pitarokoili, Kalliopi A1 - Pache, Florence A1 - Stich, Oliver A1 - Beume, Lena-Alexandra A1 - Hümmert, Martin W. A1 - Trebst, Corinna A1 - Ringelstein, Marius A1 - Aktas, Orhan A1 - Winkelmann, Alexander A1 - Buttmann, Mathias A1 - Schwarz, Alexander A1 - Zimmermann, Hanna A1 - Brandt, Alexander U. A1 - Franciotta, Diego A1 - Capobianco, Marco A1 - Kuchling, Joseph A1 - Haas, Jürgen A1 - Korporal-Kuhnke, Mirjam A1 - Lillevang, Soeren Thue A1 - Fechner, Kai A1 - Schanda, Kathrin A1 - Paul, Friedemann A1 - Wildemann, Brigitte A1 - Reindl, Markus T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 1: Frequency, syndrome specificity, influence of disease activity, long-term course, association with AQP4-IgG, and origin JF - Journal of Neuroinflammation N2 - Background Antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) have been suggested to play a role in a subset of patients with neuromyelitis optica and related disorders. Objective To assess (i) the frequency of MOG-IgG in a large and predominantly Caucasian cohort of patients with optic neuritis (ON) and/or myelitis; (ii) the frequency of MOG-IgG among AQP4-IgG-positive patients and vice versa; (iii) the origin and frequency of MOG-IgG in the cerebrospinal fluid (CSF); (iv) the presence of MOG-IgG at disease onset; and (v) the influence of disease activity and treatment status on MOG-IgG titers. Methods 614 serum samples from patients with ON and/or myelitis and from controls, including 92 follow-up samples from 55 subjects, and 18 CSF samples were tested for MOG-IgG using a live cell-based assay (CBA) employing full-length human MOG-transfected HEK293A cells. Results MOG-IgG was detected in 95 sera from 50 patients with ON and/or myelitis, including 22/54 (40.7%) patients with a history of both ON and myelitis, 22/103 (21.4%) with a history of ON but no myelitis and 6/45 (13.3%) with a history of longitudinally extensive transverse myelitis but no ON, and in 1 control patient with encephalitis and a connective tissue disorder, all of whom were negative for AQP4-IgG. MOG-IgG was absent in 221 further controls, including 83 patients with AQP4-IgG-seropositive neuromyelitis optica spectrum disorders and 85 with multiple sclerosis (MS). MOG-IgG was found in 12/18 (67%) CSF samples from MOG-IgG-seropositive patients; the MOG-IgG-specific antibody index was negative in all cases, indicating a predominantly peripheral origin of CSF MOG-IgG. Serum and CSF MOG-IgG belonged to the complement-activating IgG1 subclass. MOG-IgG was present already at disease onset. The antibodies remained detectable in 40/45 (89%) follow-up samples obtained over a median period of 16.5 months (range 0–123). Serum titers were higher during attacks than during remission (p < 0.0001), highest during attacks of simultaneous myelitis and ON, lowest during acute isolated ON, and declined following treatment. Conclusions To date, this is the largest cohort studied for IgG to human full-length MOG by means of an up-to-date CBA. MOG-IgG is present in a substantial subset of patients with ON and/or myelitis, but not in classical MS. Co-existence of MOG-IgG and AQP4-IgG is highly uncommon. CSF MOG-IgG is of extrathecal origin. Serum MOG-IgG is present already at disease onset and remains detectable in the long-term course. Serum titers depend on disease activity and treatment status. KW - Neuromyelitis optica (NMO) KW - Devic’s syndrome KW - Optic neuritis KW - Transverse Myelitis KW - Longitudinally extensive transverse myelitis (LETM) KW - Neuromyelitis optica spectrum disorders (NMOSD) KW - Multiple sclerosis KW - Autoantibodies KW - Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) KW - Neuromyelitis optica antibodies (NMO-IgG) KW - Aquaporin-4 antibodies (AQP4-IgG) KW - Cell-based assays KW - Cerebrospinal fluid KW - Antibody index Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165659 VL - 13 IS - 279 ER - TY - JOUR A1 - Jarius, Sven A1 - Kleiter, Ingo A1 - Ruprecht, Klemens A1 - Asgari, Nasrin A1 - Pitarokoili, Kalliopi A1 - Borisow, Nadja A1 - Hümmert, Martin W. A1 - Trebst, Corinna A1 - Pache, Florence A1 - Winkelmann, Alexander A1 - Beume, Lena-Alexandra A1 - Ringelstein, Marius A1 - Stich, Oliver A1 - Aktas, Orhan A1 - Korporal-Kuhnke, Mirjam A1 - Schwarz, Alexander A1 - Lukas, Carsten A1 - Haas, Jürgen A1 - Fechner, Kai A1 - Buttmann, Mathias A1 - Bellmann-Strobl, Judith A1 - Zimmermann, Hanna A1 - Brandt, Alexander U. A1 - Franciotta, Diego A1 - Schanda, Kathrin A1 - Paul, Friedemann A1 - Reindl, Markus A1 - Wildemann, Brigitte T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 3: Brainstem involvement - frequency, presentation and outcome JF - Journal of Neuroinflammation N2 - Background Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) are present in a subset of aquaporin-4 (AQP4)-IgG-negative patients with optic neuritis (ON) and/or myelitis. Little is known so far about brainstem involvement in MOG-IgG-positive patients. Objective To investigate the frequency, clinical and paraclinical features, course, outcome, and prognostic implications of brainstem involvement in MOG-IgG-positive ON and/or myelitis. Methods Retrospective case study. Results Among 50 patients with MOG-IgG-positive ON and/or myelitis, 15 (30 %) with a history of brainstem encephalitis were identified. All were negative for AQP4-IgG. Symptoms included respiratory insufficiency, intractable nausea and vomiting (INV), dysarthria, dysphagia, impaired cough reflex, oculomotor nerve palsy and diplopia, nystagmus, internuclear ophthalmoplegia (INO), facial nerve paresis, trigeminal hypesthesia/dysesthesia, vertigo, hearing loss, balance difficulties, and gait and limb ataxia; brainstem involvement was asymptomatic in three cases. Brainstem inflammation was already present at or very shortly after disease onset in 7/15 (47 %) patients. 16/21 (76.2 %) brainstem attacks were accompanied by acute myelitis and/or ON. Lesions were located in the pons (11/13), medulla oblongata (8/14), mesencephalon (cerebral peduncles; 2/14), and cerebellar peduncles (5/14), were adjacent to the fourth ventricle in 2/12, and periaqueductal in 1/12; some had concomitant diencephalic (2/13) or cerebellar lesions (1/14). MRI or laboratory signs of blood-brain barrier damage were present in 5/12. Cerebrospinal fluid pleocytosis was found in 11/14 cases, with neutrophils in 7/11 (3-34 % of all CSF white blood cells), and oligoclonal bands in 4/14. Attacks were preceded by acute infection or vaccination in 5/15 (33.3 %). A history of teratoma was noted in one case. The disease followed a relapsing course in 13/15 (87 %); the brainstem was involved more than once in 6. Immunosuppression was not always effective in preventing relapses. Interferon-beta was followed by new attacks in two patients. While one patient died from central hypoventilation, partial or complete recovery was achieved in the remainder following treatment with high-dose steroids and/or plasma exchange. Brainstem involvement was associated with a more aggressive general disease course (higher relapse rate, more myelitis attacks, more frequently supratentorial brain lesions, worse EDSS at last follow-up). Conclusions Brainstem involvement is present in around one third of MOG-IgG-positive patients with ON and/or myelitis. Clinical manifestations are diverse and may include symptoms typically seen in AQP4-IgG-positive neuromyelitis optica, such as INV and respiratory insufficiency, or in multiple sclerosis, such as INO. As MOG-IgG-positive brainstem encephalitis may take a serious or even fatal course, particular attention should be paid to signs or symptoms of additional brainstem involvement in patients presenting with MOG-IgG-positive ON and/or myelitis. KW - Myelin oligodendrocyte glycoprotein (MOG) antibodies KW - MOG-IgG KW - Neuromyelitis optica spectrum disorders (NMOSD) KW - Brainstem encephalitis KW - Rhombencephalitis KW - Optic neuritis KW - Myelitis KW - Longitudinally extensive transverse myelitis (LETM) KW - Cerebellitis KW - Ataxia KW - Respiratory insufficiency KW - Intractable nausea and vomiting KW - Facial nerve palsy KW - Diplopia Internuclear ophthalmoplegia (INO) KW - Hearing loss KW - Aquaporin-4 antibodies (AQP4-Ig, NMO-IgG)G Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165543 VL - 13 IS - 281 ER - TY - JOUR A1 - Pache, Florence A1 - Zimmermann, Hanna A1 - Mikolajczak, Janine A1 - Schumacher, Sophie A1 - Lacheta, Anna A1 - Oertel, Frederike C. A1 - Bellmann-Strobl, Judith A1 - Jarius, Sven A1 - Wildemann, Brigitte A1 - Reindl, Markus A1 - Waldman, Amy A1 - Soelberg, Kerstin A1 - Asgari, Nasrin A1 - Ringelstein, Marius A1 - Aktas, Orhan A1 - Gross, Nikolai A1 - Buttmann, Mathias A1 - Ach, Thomas A1 - Ruprecht, Klemens A1 - Paul, Friedemann A1 - Brandt, Alexander U. T1 - MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 4: Afferent visual system damage after optic neuritis in MOG-IgG-seropositive versus AQP4-IgG-seropositive patients JF - Journal of Neuroinflammation N2 - Background Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been reported in patients with aquaporin-4 antibody (AQP4-IgG)-negative neuromyelitis optica spectrum disorders (NMOSD). The objective of this study was to describe optic neuritis (ON)-induced neuro-axonal damage in the retina of MOG-IgG-positive patients in comparison with AQP4-IgG-positive NMOSD patients. Methods Afferent visual system damage following ON was bilaterally assessed in 16 MOG-IgG-positive patients with a history of ON and compared with that in 16 AQP4-IgG-positive NMOSD patients. In addition, 16 healthy controls matched for age, sex, and disease duration were analyzed. Study data included ON history, retinal optical coherence tomography, visual acuity, and visual evoked potentials. Results Eight MOG-IgG-positive patients had a previous diagnosis of AQP4-IgG-negative NMOSD with ON and myelitis, and eight of (mainly recurrent) ON. Twenty-nine of the 32 eyes of the MOG-IgG-positive patients had been affected by at least one episode of ON. Peripapillary retinal nerve fiber layer thickness (pRNFL) and ganglion cell and inner plexiform layer volume (GCIP) were significantly reduced in ON eyes of MOG-IgG-positive patients (pRNFL = 59 ± 23 μm; GCIP = 1.50 ± 0.34 mm3) compared with healthy controls (pRNFL = 99 ± 6 μm, p < 0.001; GCIP = 1.97 ± 0.11 mm3, p < 0.001). Visual acuity was impaired in eyes after ON in MOG-IgG-positive patients (0.35 ± 0.88 logMAR). There were no significant differences in any structural or functional visual parameters between MOG-IgG-positive and AQP4-IgG-positive patients (pRNFL: 59 ± 21 μm; GCIP: 1.41 ± 0.27 mm3; Visual acuity = 0.72 ± 1.09 logMAR). Importantly, MOG-IgG-positive patients had a significantly higher annual ON relapse rate than AQP4-IgG-positive patients (median 0.69 vs. 0.29 attacks/year, p = 0.004), meaning that on average a single ON episode caused less damage in MOG-IgG-positive than in AQP4-IgG-positive patients. pRNFL and GCIP loss correlated with the number of ON episodes in MOG-IgG-positive patients (p < 0.001), but not in AQP4-IgG-positive patients. Conclusions Retinal neuro-axonal damage and visual impairment after ON in MOG-IgG-positive patients are as severe as in AQP4-IgG-positive NMOSD patients. In MOG-IgG-positive patients, damage accrual may be driven by higher relapse rates, whereas AQP4-IgG-positive patients showed fewer but more severe episodes of ON. Given the marked damage in some of our MOG-IgG-positive patients, early diagnosis and timely initiation and close monitoring of immunosuppressive therapy are important. KW - Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) KW - aquaporin-4 antibodies (AQP4-IgG) KW - NMO-IgG KW - neuromyelitis optica KW - Devic syndrome KW - neuromyelitis optica spectrum disorders (NMOSD) KW - optic neuritis KW - optical coherence tomography KW - visual evoked potentials KW - visual acuity KW - retinal neuro-axonal damage Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165551 VL - 13 IS - 282 ER - TY - JOUR A1 - Brandt, Alexander U. A1 - Zimmermann, Hanna A1 - Kaufhold, Falko A1 - Promesberger, Julia A1 - Schippling, Sven A1 - Finis, David A1 - Aktas, Orhan A1 - Geis, Christian A1 - Ringelstein, Marius A1 - Ringelstein, E. Bernd A1 - Hartung, Hans-Peter A1 - Paul, Friedemann A1 - Kleffner, Ilka A1 - Dörr, Jan T1 - Patterns of Retinal Damage Facilitate Differential Diagnosis between Susac Syndrome and MS JF - PLoS One N2 - Susac syndrome, a rare but probably underdiagnosed combination of encephalopathy, hearing loss, and visual deficits due to branch retinal artery occlusion of unknown aetiology has to be considered as differential diagnosis in various conditions. Particularly, differentiation from multiple sclerosis is often challenging since both clinical presentation and diagnostic findings may overlap. Optical coherence tomography is a powerful and easy to perform diagnostic tool to analyse the morphological integrity of retinal structures and is increasingly established to depict characteristic patterns of retinal pathology in multiple sclerosis. Against this background we hypothesised that differential patterns of retinal pathology facilitate a reliable differentiation between Susac syndrome and multiple sclerosis. In this multicenter cross-sectional observational study optical coherence tomography was performed in nine patients with a definite diagnosis of Susac syndrome. Data were compared with age-, sex-, and disease duration-matched relapsing remitting multiple sclerosis patients with and without a history of optic neuritis, and with healthy controls. Using generalised estimating equation models, Susac patients showed a significant reduction in either or both retinal nerve fibre layer thickness and total macular volume in comparison to both healthy controls and relapsing remitting multiple sclerosis patients. However, in contrast to the multiple sclerosis patients this reduction was not distributed over the entire scanning area but showed a distinct sectorial loss especially in the macular measurements. We therefore conclude that patients with Susac syndrome show distinct abnormalities in optical coherence tomography in comparison to multiple sclerosis patients. These findings recommend optical coherence tomography as a promising tool for differentiating Susac syndrome from MS. KW - optical coherence tomography KW - vasculopathy KW - artery occlusion KW - hearing loss KW - microangiopathy KW - brain KW - endotheliopathy KW - antibodies KW - multiple-sclerosis KW - retinocochleocerebral Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134013 VL - 7 IS - 6 ER - TY - JOUR A1 - Wildgruber, Moritz A1 - Aschenbrenner, Teresa A1 - Wendorff, Heiko A1 - Czubba, Maria A1 - Glinzer, Almut A1 - Haller, Bernhard A1 - Schiemann, Matthias A1 - Zimmermann, Alexander A1 - Berger, Hermann A1 - Eckstein, Hans-Henning A1 - Meier, Reinhard A1 - Wohlgemuth, Walter A. A1 - Libby, Peter A1 - Zernecke, Alma T1 - The "Intermediate" CD14\(^{++}\)CD16\(^{+}\) monocyte subset increases in severe peripheral artery disease in humans JF - Scientific Reports N2 - Monocytes are key players in atherosclerotic. Human monocytes display a considerable heterogeneity and at least three subsets can be distinguished. While the role of monocyte subset heterogeneity has already been well investigated in coronary artery disease (CAD), the knowledge about monocytes and their heterogeneity in peripheral artery occlusive disease (PAOD) still is limited. Therefore, we aimed to investigate monocyte subset heterogeneity in patients with PAOD. Peripheral blood was obtained from 143 patients suffering from PAOD (Rutherford stage I to VI) and three monocyte subsets were identified by flow cytometry: CD14\(^{++}\)CD16\(^{-}\) classical monocytes, CD14\(^{+}\)CD16\(^{++}\) non-classical monocytes and CD14\(^{++}\)CD16\(^{+}\) intermediate monocytes. Additionally the expression of distinct surface markers (CD106, CD162 and myeloperoxidase MPO) was analyzed. Proportions of CD14\(^{++}\)CD16\(^{+}\) intermediate monocyte levels were significantly increased in advanced stages of PAOD, while classical and non-classical monocytes displayed no such trend. Moreover, CD162 and MPO expression increased significantly in intermediate monocyte subsets in advanced disease stages. Likewise, increased CD162 and MPO expression was noted in CD14\(^{++}\)CD16\(^{-}\) classical monocytes. These data suggest substantial dynamics in monocyte subset distributions and phenotypes in different stages of PAOD, which can either serve as biomarkers or as potential therapeutic targets to decrease the inflammatory burden in advanced stages of atherosclerosis. KW - peripheral artery occlusive disease KW - monocyte subset KW - humans Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167476 VL - 6 IS - 39483 ER - TY - JOUR A1 - Djuzenova, Cholpon S. A1 - Fiedler, Vanessa A1 - Memmel, Simon A1 - Katzer, Astrid A1 - Sisario, Dmitri A1 - Brosch, Philippa K. A1 - Göhrung, Alexander A1 - Frister, Svenja A1 - Zimmermann, Heiko A1 - Flentje, Michael A1 - Sukhorukov, Vladimir L. T1 - Differential effects of the Akt inhibitor MK-2206 on migration and radiation sensitivity of glioblastoma cells JF - BMC Cancer N2 - Background Most tumor cells show aberrantly activated Akt which leads to increased cell survival and resistance to cancer radiotherapy. Therefore, targeting Akt can be a promising strategy for radiosensitization. Here, we explore the impact of the Akt inhibitor MK-2206 alone and in combination with the dual PI3K and mTOR inhibitor PI-103 on the radiation sensitivity of glioblastoma cells. In addition, we examine migration of drug-treated cells. Methods Using single-cell tracking and wound healing migration tests, colony-forming assay, Western blotting, flow cytometry and electrorotation we examined the effects of MK-2206 and PI-103 and/or irradiation on the migration, radiation sensitivity, expression of several marker proteins, DNA damage, cell cycle progression and the plasma membrane properties in two glioblastoma (DK-MG and SNB19) cell lines, previously shown to differ markedly in their migratory behavior and response to PI3K/mTOR inhibition. Results We found that MK-2206 strongly reduces the migration of DK-MG but only moderately reduces the migration of SNB19 cells. Surprisingly, MK-2206 did not cause radiosensitization, but even increased colony-forming ability after irradiation. Moreover, MK-2206 did not enhance the radiosensitizing effect of PI-103. The results appear to contradict the strong depletion of p-Akt in MK-2206-treated cells. Possible reasons for the radioresistance of MK-2206-treated cells could be unaltered or in case of SNB19 cells even increased levels of p-mTOR and p-S6, as compared to the reduced expression of these proteins in PI-103-treated samples. We also found that MK-2206 did not enhance IR-induced DNA damage, neither did it cause cell cycle distortion, nor apoptosis nor excessive autophagy. Conclusions Our study provides proof that MK-2206 can effectively inhibit the expression of Akt in two glioblastoma cell lines. However, due to an aberrant activation of mTOR in response to Akt inhibition in PTEN mutated cells, the therapeutic window needs to be carefully defined, or a combination of Akt and mTOR inhibitors should be considered. KW - DNA damage KW - glioblastoma multiforme KW - histone H2AX KW - irradiation KW - migration KW - mTOR KW - PTEN KW - p53 KW - radiation sensitivity KW - wound healing Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200290 VL - 19 ER -