@article{SubramaniyanSridharanHowardetal.2020, author = {Subramaniyan, Boopathi and Sridharan, Sangita and Howard, Cory M. and Tilley, Augustus M.C. and Basuroy, Tupa and Serna, Ivana de la and Butt, Elke and Raman, Dayanidhi}, title = {Role of the CXCR4-LASP1 axis in the stabilization of Snail1 in triple-negative breast cancer}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {9}, issn = {2072-6694}, doi = {10.3390/cancers12092372}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211217}, year = {2020}, abstract = {The CXCL12-CXCR4 axis plays a vital role in many steps of breast cancer metastasis, but the molecular mechanisms have not been fully elucidated. We previously reported that activation of CXCR4 by CXCL12 promotes the nuclear localization of LASP1 (LIM and SH3 protein 1). The nuclear LASP1 then interacts with Snail1 in triple-negative breast cancer (TNBC) cell lines. In this study, we report that the nuclear accumulation and retention of Snail1 was dependent on an increase in nuclear LASP1 levels driven by active CXCR4. The CXCR4-LASP1 axis may directly regulate the stabilization of nuclear Snail1, by upregulating nuclear levels of pS473-Akt, pS9-GSK-3β, A20, and LSD1. Furthermore, the activation of CXCR4 induced association of LASP1 with Snail1, A20, GSK-3β, and LSD1 endogenously. Thus, nuclear LASP1 may also regulate protein-protein interactions that facilitate the stability of Snail1. Genetic ablation of LASP1 resulted in the mislocalization of nuclear Snail1, loss of the ability of TNBC cells to invade Matrigel and a dysregulated expression of both epithelial and mesenchymal markers, including an increased expression of ALDH1A1, a marker for epithelial breast cancer stem-like cells. Our findings reveal a novel role for the CXCR4-LASP1 axis in facilitating the stability of nuclear localized Snail1.}, language = {en} } @article{RajendranBoettigerStadelmannetal.2021, author = {Rajendran, Ranjithkumar and B{\"o}ttiger, Gregor and Stadelmann, Christine and Karnati, Srikanth and Berghoff, Martin}, title = {FGF/FGFR pathways in multiple sclerosis and in its disease models}, series = {Cells}, volume = {10}, journal = {Cells}, number = {4}, issn = {2073-4409}, doi = {10.3390/cells10040884}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236594}, year = {2021}, abstract = {Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system (CNS) affecting more than two million people worldwide. In MS, oligodendrocytes and myelin sheaths are destroyed by autoimmune-mediated inflammation, while remyelination is impaired. Recent investigations of post-mortem tissue suggest that Fibroblast growth factor (FGF) signaling may regulate inflammation and myelination in MS. FGF2 expression seems to correlate positively with macrophages/microglia and negatively with myelination; FGF1 was suggested to promote remyelination. In myelin oligodendrocyte glycoprotein (MOG)\(_{35-55}\)-induced experimental autoimmune encephalomyelitis (EAE), systemic deletion of FGF2 suggested that FGF2 may promote remyelination. Specific deletion of FGF receptors (FGFRs) in oligodendrocytes in this EAE model resulted in a decrease of lymphocyte and macrophage/microglia infiltration as well as myelin and axon degeneration. These effects were mediated by ERK/Akt phosphorylation, a brain-derived neurotrophic factor, and downregulation of inhibitors of remyelination. In the first part of this review, the most important pharmacotherapeutic principles for MS will be illustrated, and then we will review recent advances made on FGF signaling in MS. Thus, we will suggest application of FGFR inhibitors, which are currently used in Phase II and III cancer trials, as a therapeutic option to reduce inflammation and induce remyelination in EAE and eventually MS.}, language = {en} } @article{HausmannBrandtKoecheletal.2015, author = {Hausmann, Stefan and Brandt, Evelyn and K{\"o}chel, Carolin and Einsele, Hermann and Bargou, Ralf C. and Seggewiss-Bernhardt, Ruth and St{\"u}hmer, Thorsten}, title = {Loss of serum and glucocorticoid-regulated kinase 3 (SGK3) does not affect proliferation and survival of multiple myeloma cell lines}, series = {PLoS ONE}, volume = {10}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0122689}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148708}, pages = {e0122689}, year = {2015}, abstract = {Multiple myeloma (MM) is a generally fatal plasma cell cancer that often shows activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway. Targeted pharmacologic therapies, however, have not yet progressed beyond the clinical trial stage, and given the complexity of the PI3K/Akt signalling system (e.g. multiple protein isoforms, diverse feedback regulation mechanisms, strong variability between patients) it is mandatory to characterise its ramifications in order to better guide informed decisions about the best therapeutic approaches. Here we explore whether serum and glucocorticoid-regulated kinase 3 (SGK3), a potential downstream effector of PI3K, plays a role in oncogenic signalling in MM cells-either in concert with or independent of Akt. SGK3 was expressed in all MM cell lines and in all primary MM samples tested. Four MM cell lines representing a broad range of intrinsic Akt activation (very strong: MM. 1s, moderate: L 363 and JJN-3, absent: AMO-1) were chosen to test the effects of transient SGK3 knockdown alone and in combination with pharmacological inhibition of Akt, PI3K-p110\(\alpha\), or in the context of serum starvation. Although the electroporation protocol led to strong SGK3 depletion for at least 5 days its absence had no substantial effect on the activation status of potential downstream substrates, or on the survival, viability or proliferation of MM cells in all experimental contexts tested. We conclude that it is unlikely that SGK3 plays a significant role for oncogenic signalling in multiple myeloma.}, language = {en} } @article{SchmidtLiuLiuetal.2014, author = {Schmidt, Sebastian and Liu, Guoxing and Liu, Guilai and Yang, Wenting and Honisch, Sabina and Pantelakos, Stavros and Stournaras, Christos and H{\"o}nig, Arnd and Lang, Florian}, title = {Enhanced Orai1 and STIM1 expression as well as store operated \(Ca^{2+}\) entry in therapy resistant ovary carcinoma cells}, series = {Oncotarget}, volume = {5}, journal = {Oncotarget}, number = {13}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121423}, pages = {4799-810}, year = {2014}, abstract = {Mechanisms underlying therapy resistance of tumor cells include protein kinase Akt. Putative Akt targets include store-operated \(Ca^{2+}\)-entry (SOCE) accomplished by pore forming ion channel unit Orai1 and its regulator STIM1. We explored whether therapy resistant (A2780cis) differ from therapy sensitive (A2780) ovary carcinoma cells in Akt, Orai1, and STIM1 expression, \(Ca^{2+}\)-signaling and cell survival following cisplatin (100µM) treatment. Transcript levels were quantified with RT-PCR, protein abundance with Western blotting, cytosolic \(Ca^{2+}\)-activity ([\(Ca^{2+}\)]i) with Fura-2-fluorescence, SOCE from increase of [\(Ca^{2+}\)]i following \(Ca^{2+}\)-readdition after Ca2+-store depletion, and apoptosis utilizing flow cytometry. Transcript levels of Orai1 and STIM1, protein expression of Orai1, STIM1, and phosphorylated Akt, as well as SOCE were significantly higher in A2780cis than A2780 cells. SOCE was decreased by Akt inhibitor III (SH-6, 10µM) in A2780cis but not A2780 cells and decreased in both cell lines by Orai1 inhibitor 2-aminoethoxydiphenyl borate (2-ABP, 50µM). Phosphatidylserine exposure and late apoptosis following cisplatin treatment were significantly lower in A2780cis than A2780 cells, a difference virtually abolished by SH-6 or 2-ABP. In conclusion, Orai1/STIM1 expression and function are increased in therapy resistant ovary carcinoma cells, a property at least in part due to enhanced Akt activity and contributing to therapy resistance in those cells.}, language = {en} } @article{KugerCoerekPolatetal.2014, author = {Kuger, Sebastian and C{\"o}rek, Emre and Polat, B{\"u}lent and K{\"a}mmerer, Ulrike and Flentje, Michael and Djuzenova, Cholpon S.}, title = {Novel PI3K and mTOR Inhibitor NVP-BEZ235 Radiosensitizes Breast Cancer Cell Lines under Normoxic and Hypoxic Conditions}, doi = {10.4137/BCBCR.S13693}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112708}, year = {2014}, abstract = {In the present study, we assessed, if the novel dual phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor NVP-BEZ235 radiosensitizes triple negative (TN) MDA-MB-231 and estrogen receptor (ER) positive MCF-7 cells to ionizing radiation under various oxygen conditions, simulating different microenvironments as occurring in the majority of breast cancers (BCs). Irradiation (IR) of BC cells cultivated in hypoxic conditions revealed increased radioresistance compared to normoxic controls. Treatment with NVP-BEZ235 completely circumvented this hypoxia-induced effects and radiosensitized normoxic, reoxygenated, and hypoxic cells to similar extents. Furthermore, NVP-BEZ235 treatment suppressed HIF-1α expression and PI3K/mTOR signaling, induced autophagy, and caused protracted DNA damage repair in both cell lines in all tested oxygen conditions. Moreover, after incubation with NVP-BEZ235, MCF-7 cells revealed depletion of phospho-AKT and considerable signs of apoptosis, which were signifi-cantly enhanced by radiation. Our findings clearly demonstrate that NVP-BEZ235 has a clinical relevant potential as a radiosensitizer in BC treatment.}, language = {en} }