AG Cytoskeletal Dynamics

Almost all processes in multicellular organisms are determined by the - in the best case perfect - interaction between individual cells. The communication between cells (signal transduction) can lead to very dynamic processes such as cell division, endo- and exocytosis as well as movement (migration) of cells. Among the most mobile cells of the human organism are the immune cells, which are attracted to the site of infection by chemokines. But also nerve cells (neurons), bone cells (osteoblasts, osteoclasts), skin and connective tissue cells are very mobile. During migration, the cytoskeleton, which consists of intermediate filaments, microtubule and actin filaments, is constantly being built up and broken down. The driving force for migration is provided by the dynamics of the actin filaments. Here, actin filaments are built up at the front ends of the cells and degraded at the rear ends. These actin filament dynamics are controlled by actin binding proteins. Microtubules, on the other hand, mainly regulate the movement of spindle fibers and the transport of vesicles. Therefore, cell division and protein secretion are largely controlled by these filaments. Similar to actin filaments, microtubule dynamics are regulated by associated proteins.

Alterations in the regulation and/or binding of cytoskeleton-associated proteins can result in cellular disorders. This is particularly important in autoimmune diseases, neuronal disorders and tumor cell metastasis. For this reason, it is a very interesting approach to search for cytoskeleton-associated proteins that are essential for the function of immune cells, neurons and tumor cells. Depending on the clinical picture, stimulation or inhibition of these proteins should attenuate the disorder.

Our group mainly investigates the function of cytoskeleton-associated proteins in metastasis and chemoresistance of tumor cells.

We have been able to identify proteins that are involved in the regulation of these processes. The most important ones are briefly described below:

Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA)

Since over ten years, we have been researching the role of inositol-1,4,5-trisphosphate 3-kinase-A (InsP3Kinase or ITPKA) in tumorigenesis. Extensive investigations showed that ITPKA is overexpressed in lung cancer cells and controls metastasis of these cells (Windhorst et al., 2008; 2010; 2011, 2017), while in normal cells the protein is mainly expressed in neurons (Windhorst et al., 2017). ITPKA controls InsP3-mediated calcium signals and cross-links actin filaments (Figure on the right site). Thereby, ITPKA is involved in the regulation of tumor growth and metastasis (Ashour et al., 2015; Windhorst et al., 2017).

Overexpression of ITPKA in lung cancer cells is induced by misregulation of the repressor element-1 silencing transcription factor REST/NRSF (Chang et al., 2011). This transcriptional repressor normally leads to the repression of non-neuronal genes in non-neuronal tissue. In many tumor cells, REST/NRSF is misregulated, resulting in the expression of neuronal genes.

We have already succeeded in identifying inhibitors of InsP3kinase activity, of which BIP-4 (Schröder et al., 2013; 2015) is the most promising candidate. Currently, we are working on the optimization of BIP-4 to enable selective inhibition of InsP3kinase activity in tumor cells. Furthermore, we plan to search for inhibitors against the actin crosslinking activity of ITPKA.

Diaphanous homologous 1 and 2 (DIAPH1 and 2)

In order to identify potential targets for therapy of metastasized colorectal carcinoma cells, we analyzed the role of cytoskeleton-associated proteins in metastasis and identified the actin- and tubulin-regulating protein DIAPH1 (Lin et al., 2013,2015). In addition, we were able to show that DIAPH1 promotes adhesion of colon cancer cells by stabilizing microtubules (Lin et al., 2015).

The isoform 2 (DIAPH2), by contrast has no effect on adhesion, but is important for proliferation of colorectal carcinoma cells. Strong expression of DIAPH2 in these cells increases the dynamics of spindle microtubules by stimulating microtubule polymerization, thereby accelerating mitosis progression (Grüb et al., 2019 and Figure below).

Since misregulation of microtubule dynamics can lead to chromosomal instability (CIN), we are currently investigating the role of DIAPH1 + 2 in this process. First results indicate that DIAPH1 is involved in the control of CIN.

In addition, in collaboration with the Department of Gynecology we could show a clear correlation between strong DIAPH1 expression and improved survival of ovarian cancer patients. We are now investigating whether DIAPH1 is involved in the development of paclitaxel resistance. Paclitaxel is an established chemotherapeutic agent that inhibits the dynamics of microtubules and therefore blocks cell division. It is possible that the association of DIAPH1 with microtubules alters the paclitaxel binding.

Centrosomal Protein 55 (CEP55)

CEP55 is a scaffold protein that is overexpressed in many ovarian cancers and is essential for their cell division. In normal cells, CEP55 is mainly expressed in testis and thymus, making it a very good target for selective tumor therapy. Using SKOV-3 cells, we could show that CEP55 depletion reduces chromosomal instability, midbody-mediated cell separation (see Figure right), cell division and colony formation. Our data suggest that these effects are not only controlled by the scaffold activity of CEP55, but also by its microtubule stabilizing activity. To test this hypothesis, we plan to identify the microtubule-binding domain in the CEP55 protein and conduct rescue experiments with microtubule-binding deficient mutants and CEP55 mutants with reduced scaffold activity. If microtubule-binding of CEP55 is essential for its effect on ovarian cancer cell progression, we plan to investigate in follow-up projects whether CEP55 inhibition is suitable for the therapy of chemoresistant ovarian cancer cells.


  • Cloning and protein purification
  • Extraction of DNA, mRNA and proteins
  • Enzyme Kinetic Assays
  • Determination of the cytosolic calcium concentration
  • Western blotting, immunoprecipitation, immunocytology and histology
  • Migration, Invasion and Adhesion Assays
  • Transient and stable overexpression and shRNA-mediated downregulation of proteins
  • Various techniques for analysis of actin and microtubule dynamics in cell-free systems
  • Fluorescence Microscopy


Supervision of bachelor, master and doctoral theses

Publications Windhorst Group

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Tubulin Tyrosine Ligase Like 4 (TTLL4) overexpression in breast cancer cells is associated with brain metastasis and alters exosome biogenesis
Arnold J, Schattschneider J, Blechner C, Krisp C, Schlüter H, Schweizer M, Nalaskowski M, Oliveira-Ferrer L, Windhorst S
J EXP CLIN CANC RES. 2020;39(1):205.

Physiological relevance of the neuronal isoform of inositol-1,4,5-trisphosphate 3-kinases in mice
Blechner C, Becker L, Fuchs H, Rathkolb B, Prehn C, Adler T, Calzada-Wack J, Garrett L, Gailus-Durner V, Morellini F, Conrad S, Hölter S, Wolf E, Klopstock T, Adamski J, Busch D, de Angelis M, Schmeisser M, Windhorst S
NEUROSCI LETT. 2020;735:135206.

Conserved Tao Kinase Activity Regulates Dendritic Arborization, Cytoskeletal Dynamics, and Sensory Function in Drosophila
Hu C, Kanellopoulos A, Richter M, Petersen M, Konietzny A, Tenedini F, Hoyer N, Cheng L, Poon C, Harvey K, Windhorst S, Parrish J, Mikhaylova M, Bagni C, Calderon de Anda F, Soba P
J NEUROSCI. 2020;40(9):1819-1833.

Modeling Spontaneous Bone Metastasis Formation of Solid Human Tumor Xenografts in Mice
Labitzky V, Baranowsky A, Maar H, Hanika S, Starzonek S, Ahlers A, Stübke K, Koziolek E, Heine M, Schäfer P, Windhorst S, Jücker M, Riecken K, Amling M, Schinke T, Schumacher U, Valentiner U, Lange T
CANCERS. 2020;12(2):.

Characterization of the substrate specificity of the inositol 5-phosphatase SHIP1
Nelson N, Wundenberg T, Lin H, Rehbach C, Horn S, Windhorst S, Jücker M
BIOCHEM BIOPH RES CO. 2020;524(2):366-370.

Mice lacking plastin-3 display a specific defect of cortical bone acquisition
Yorgan T, Sari H, Rolvien T, Windhorst S, Failla A, Kornak U, Oheim R, Amling M, Schinke T
BONE. 2020;130:115062.


Inositol hexakisphosphate increases the size of platelet aggregates
Brehm M, Klemm U, Rehbach C, Erdmann N, Kolšek K, Lin H, Aponte-Santamaría C, Gräter F, Rauch B, Riley A, Mayr G, Potter B, Windhorst S
BIOCHEM PHARMACOL. 2019;161:14-25.

New options of cancer treatment employing InsP6
Brehm M, Windhorst S
BIOCHEM PHARMACOL. 2019;163:206-214.

The formin Drosophila homologue of Diaphanous2 (Diaph2) controls microtubule dynamics in colorectal cancer cells independent of its FH2-domain
Grueb S, Muhs S, Popp Y, Schmitt S, Geyer M, Lin Y, Windhorst S
SCI REP-UK. 2019;9(1):5352.

Radial somatic F-actin organization affects growth cone dynamics during early neuronal development
Meka D, Scharrenberg R, Zhao B, Kobler O, König T, Schaefer I, Schwanke B, Klykov S, Richter M, Eggert D, Windhorst S, Dotti C, Kreutz M, Mikhaylova M, Calderon de Anda F
EMBO REP. 2019;20(12):e47743.

The Actin Binding Protein Plastin-3 Is Involved in the Pathogenesis of Acute Myeloid Leukemia
Velthaus A, Cornils K, Hennigs J, Grüb S, Stamm H, Wicklein D, Bokemeyer C, Heuser M, Windhorst S, Fiedler W, Wellbrock J
CANCERS. 2019;11(11):.


Effect of the actin- and calcium-regulating activities of ITPKB on the metastatic potential of lung cancer cells
Bäder S, Glaubke E, Grüb S, Muhs S, Wellbrock J, Nalaskowski M, Lange T, Windhorst S
BIOCHEM J. 2018;475(12):2057-2071.

Differential Proteome Analysis of Human Neuroblastoma Xenograft Primary Tumors and Matched Spontaneous Distant Metastases
Hänel L, Gosau T, Maar H, Valentiner U, Schumacher U, Riecken K, Windhorst S, Hansen N, Heikaus L, Wurlitzer M, Nolte I, Schlüter H, Lange T
SCI REP-UK. 2018;8(1):13986.

Clinical relevance of cytoskeleton associated proteins for ovarian cancer
Schiewek J, Schumacher U, Lange T, Joosse S, Wikman H, Pantel K, Mikhaylova M, Kneussel M, Linder S, Schmalfeldt B, Oliveira-Ferrer L, Windhorst S
J CANCER RES CLIN. 2018;144(11):2195-2205.


Strong fascin expression promotes metastasis independent of its F-actin bundling activity
Heinz L, Muhs S, Schiewek J, Grüb S, Nalaskowski M, Lin Y, Wikman H, Oliveira-Ferrer L, Lange T, Wellbrock J, Konietzny A, Mikhaylova M, Windhorst S
ONCOTARGET. 2017;8(66):110077-110091.

Tight Junction Proteins Claudin-1 and Occludin Are Important for Cutaneous Wound Healing
Volksdorf T, Heilmann J, Eming S, Schawjinski K, Zorn-Kruppa M, Ueck C, Vidal-Y-Sy S, Windhorst S, Jücker M, Moll I, Brandner J
AM J PATHOL. 2017;187(6):1301-1312.

Inositol-1,4,5-trisphosphate 3-kinase-A (ITPKA) is frequently over-expressed and functions as an oncogene in several tumor types
Windhorst S, Song K, Gazdar A
BIOCHEM PHARMACOL. 2017;137:1-9.

Microtubules Modulate F-actin Dynamics during Neuronal Polarization
Zhao B, Meka P, Scharrenberg R, König T, Schwanke B, Kobler O, Windhorst S, Kreutz M, Mikhaylova M, Calderon de Anda F
SCI REP-UK. 2017;7(1):9583.


Smooth Muscle-Alpha Actin Inhibits Vascular Smooth Muscle Cell Proliferation and Migration by Inhibiting Rac1 Activity
Chen L, DeWispelaere A, Dastvan F, Osborne W, Blechner C, Windhorst S, Daum G
PLOS ONE. 2016;11(5):e0155726.

Control of aromatase in hippocampal neurons
Fester L, Brandt N, Windhorst S, Pröls F, Bläute C, Rune G
J STEROID BIOCHEM. 2016;160:9-14.

Inositol-1,4,5-trisphosphate-3-kinase-A controls morphology of hippocampal dendritic spines
Köster J, Leggewie B, Blechner C, Brandt N, Fester L, Rune G, Schweizer M, Kindler S, Windhorst S
CELL SIGNAL. 2016;28(1):83-90.

Diaphanous-related formin 1 as a target for tumor therapy
Lin Y, Windhorst S
BIOCHEM SOC T. 2016;44(5):1289-1293.


The catalytic domain of inositol-1,4,5-trisphosphate 3-kinase-a contributes to ITPKA-induced modulation of F-actin
Ashour D, Pelka B, Jaaks P, Wundenberg T, Blechner C, Zobiak B, Failla A, Windhorst S
Cytoskeleton (Hoboken). 2015;72(2):93-100.

Drosophila homologue of Diaphanous 1 (DIAPH1) controls the metastatic potential of colon cancer cells by regulating microtubule-dependent adhesion
Lin Y, Bhuwania R, Gromova K, Failla A, Lange T, Riecken K, Linder S, Kneussel M, Izbicki J, Windhorst S
ONCOTARGET. 2015;6(21):18577-89.

Ex vivo aorta patch model for analysis of cellular adhesion
Lin Y, Thata R, Failla A, Geissen M, Daum G, Windhorst S
TISSUE CELL. 2015;47(3):266-72.

The new InsP3Kinase inhibitor BIP-4 is competitive to InsP3 and blocks proliferation and adhesion of lung cancer cells
Schröder D, Tödter K, Gonzalez B, Franco-Echevarría E, Rohaly G, Blechner C, Lin H, Mayr G, Windhorst S
BIOCHEM PHARMACOL. 2015;96(2):143-50.


Expression of DIAPH1 is up-regulated in colorectal cancer and its down-regulation strongly reduces the metastatic capacity of colon carcinoma cells
Lin Y, Izbicki J, König A, Habermann J, Blechner C, Lange T, Schumacher U, Windhorst S
INT J CANCER. 2014;134(7):1571-82.

Expression, Purification and preliminary X-Ray diffraction of a pathogenic bacterial protease from Stenotrophomonas maltophilia
Negm A, Windhorst S, Betzel C, Akrem A, Weber W
World J Pharm Pharm Sci. 2014;3(10):13-23.

Cellular internalisation of an inositol phosphate visualised by using fluorescent InsP5
Riley A, Windhorst S, Lin H, Potter B
CHEMBIOCHEM. 2014;15(1):57-67.


Expression Regulation of the Metastasis-Promoting Protein InsP3-Kinase-A in Tumor Cells.
Chang L, Schwarzenbach H, Meyer-Staeckling S, Brandt B, Mayr G, Weitzel J, Windhorst S

Combined targeting of AKT and mTOR using MK-2206 and RAD001 is synergistic in the treatment of cholangiocarcinoma
Ewald F, Grabinski N, Grottke A, Windhorst S, Nörz D, Carstensen L, Staufer K, Hofmann B, Diehl F, David K, Schumacher U, Nashan B, Jücker M
INT J CANCER. 2013;133(9):2065-76.

Malignant H1299 tumour cells preferentially internalize iron-bound inositol hexakisphosphate
Helmis C, Blechner C, Lin H, Schweizer M, Mayr G, Nielsen P, Windhorst S
BIOSCIENCE REP . 2013;33(5):.

Identification of a new membrane-permeable inhibitor against inositol-1,4,5-trisphosphate-3-kinase A
Schröder D, Rehbach C, Seyffarth C, Neuenschwander M, Kries J, Windhorst S
BIOCHEM BIOPH RES CO. 2013;439(2):228-34.

Tumour cells can employ extracellular Ins(1,2,3,4,5,6)P(6) and multiple inositol-polyphosphate phosphatase 1 (MINPP1) dephosphorylation to improve their proliferation
Windhorst S, Lin H, Blechner C, Fanick W, Brandt L, Brehm M, Mayr G
BIOCHEM J. 2013;450(1):115-25.


Inositol-1,4,5-trisphosphate 3-kinase A regulates dendritic morphology and shapes synaptic Ca2+ transients.
Windhorst S, Minge D, Bähring R, Hüser S, Schob C, Blechner C, Lin H, Mayr G, Kindler S
CELL SIGNAL. 2012;24(3):750-757.


Human inositol 1,4,5-trisphosphate 3-kinase isoform B (IP3KB) is a nucleocytoplasmic shuttling protein specifically enriched at cortical actin filaments and at invaginations of the nuclear envelope.
Nalaskowski M, Fliegert R, Ernst O, Brehm M, Fanick W, Windhorst S, Lin H, Giehler S, Hein J, Lin Y, Mayr G
J BIOL CHEM. 2011;286(6):4500-4510.

Functional role of inositol-1,4,5-trisphosphate-3-kinase-A for motility of malignant transformed cells.
Windhorst S, Kalinina T, Schmid K, Blechner C, Kriebitzsch N, Hinsch R, Chang L, Herich L, Schumacher U, Mayr G
INT J CANCER. 2011;129(6):1300-1309.


Inositol-1,4,5-trisphosphate-3-kinase-A is a new cell motility-promoting protein that increases the metastatic potential of tumour cells by two functional activities.
Windhorst S, Fliegert R, Blechner C, Möllmann K, Hosseini Z, Guenther T, Eiben M, Chang L, Lin H, Fanick W, Schumacher U, Brandt B, Mayr G
J BIOL CHEM. 2010;285(8):5541-5554.


Ins(1,4,5)P3 3-kinase-A overexpression induces cytoskeletal reorganization via a kinase-independent mechanism.
Windhorst S, Blechner C, Lin H, Elling C, Nalaskowski M, Kirchberger T, Guse A, Mayr G
BIOCHEM J. 2008;414(3):407-417.


Intracellular localization of human Ins(1,3,4,5,6)P5 2-kinase.
Brehm M, Schenk T, Zhou X, Fanick W, Lin H, Windhorst S, Nalaskowski M, Kobras M, Shears S, Mayr G
BIOCHEM J. 2007;408(3):335-345.

Radiosensitization of tumour cell lines by the polyphenol Gossypol results from depressed double-strand break repair and not from enhanced apoptosis.
Kasten-Pisula U, Windhorst S, Dahm-Daphi J, Mayr G, Dikomey E
RADIOTHER ONCOL. 2007;83(3):296-303.


Subcellular localisation of human inositol 1,4,5-trisphosphate 3-kinase C: species-specific use of alternative export sites for nucleo-cytoplasmic shuttling indicates divergent roles of the catalytic and N-terminal domains.
Nalaskowski M, Windhorst S, Stockebrand M, Mayr G
BIOL CHEM. 2006;387(5):583-593.


Antiproliferative plant and synthetic polyphenolics are specific inhibitors of vertebrate inositol-1,4,5-trisphosphate 3-kinases and inositol polyphosphate multikinase.
Mayr G, Windhorst S, Hillemeier K
J BIOL CHEM. 2005;280(14):13229-13240.

Letzte Aktualisierung aus dem FIS: 28.02.2021 - 06:37 Uhr