HA-binding protein

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INFLUENCE OF THE HYALURONIDASE HYAL1 AND THE CD44-HYALURONAN INTERACTION FOR THE DEVELOPMENT OF BRAIN METASTASES IN BREAST CANCER: FINDING NEW POTENTIAL THERAPEUTIC APPROACHES

Involved Scientists from our clinic: F. Hamester, L. Oliveira-Ferrer. I. Witzel, E. Laakmann

Cooperation partner: C. Stürken (Institute of Anatomy und Experimental Morphology)

Project description: Around one-third of all patients with metastatic breast cancer develop brain metastases (BM). Brain metastasis negatively influences the life expectancy and quality of affected patients. Unfortunately, there are still large gaps in our understanding of the mechanisms that lead to BM development and new therapy options are urgently needed.
We have identified hyaluronidase 1 (HAYL1), a catabolic enzyme of the hyaluronan (HA) metabolism, as a marker for BM in breast cancer (Witzel et al. 2017). Based on these data, we currently investigate the molecular mechanisms underlying the development of HYAL1-mediated BM in breast cancer cells. A special focus will be set on the interaction between breast cancer cells with aberrant HYAL1 expression and the blood-brain barrier. To this end, we study the influence of HYAL1 on (A) the adhesion of tumor cells to the brain endothelium, (B) the BBB permeability and (C) the invasive ability of tumor cells through the BBB. Furthermore, the metastasis potential of breast cancer cells with aberrant HYAL1 expression will be investigated in an in vivo mouse model. In addition, the role of CD44, the main HA receptor at the surface of breast cancer cells and essential for HA-dependent signaling, will be investigated during BM development. In this context, blocking CD44 could be an interesting therapeutic option to prevent breast cancer cells from entering the brain.

Funding: Werner-Otto-Stiftung & Hamburger Krebsgesellschaft

THE ROLE OF SMAD-SPECIFIC E3 UBIQUITIN PROTEIN LIGASE 1 (SMURF1) IN THE PROGRESSION OF BREAST CANCER: IMPACT ON THE DEVELOPMENT OF BRAIN METASTASIS

Involved Scientists: J. Artzenroth, J. Schwinn, L. Oliveira-Ferrer

Project Description: Brain metastases have a high impact on the life expectancy of patients with breast cancer. Unfortunately, we still don’t have a clear understanding of its underlying mechanisms and we lack effective prognostic markers for its early identification. Our analysis has shown that SMAD Specific E3 Ubiquitin Protein Ligase 1 (Smurf1) expression significantly correlates with diesease progression and the development of brain metastasis in HER2-enriched and triple negative breast cancer patients. Smurf1 itself is an E3-Ubiquin-Ligase with a wide range of molecular interactions and cellular functions. Among others, Smurf1 ubiquitylates RhoA in the cytoplasm, leading to cytoskeleton disruption and an increased rate of breast cancer cell migration and invasion. The aim of this project is to validate Smurf1 as a prognostic marker in breast cancer and to further analyze its specific role on the tumor cell – blood brain barrier interaction and therefore in the development of brain metastasis. Smurf1 knock-down and Smurf1 overexpression in different breast cancer cell lines are planned and the effect on breast cancer cell adhesion to endothelial cells, invasion as well as impact on permeability/integrity of the blood brain barrier will be analyzed.

Funding: Deutsche Krebshilfe

Tumor cell spheroids

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THE ROLE OF THE DESMOSOMAL PROTEIN DESMOCOLLIN-2 IN THE TUMOUR PROGRESSION OF TRIPLE NEGATIVE BREAST CANCERS

Involved scientists from our department: F. Reimer, S. Bryan L. Oliveira-Ferrer

Cooperation partner: C. Stürken (Institute of Anatomy und Experimental Morphology)

Project description: Desmosomes are cell junctions which promote cell-cell contact and stabilise neighbouring epithelial cells. Desmosomal proteins have been associated with tumour cell aggregation, and particularly high plakoglobin expression levels have been found in circulating tumour cell clusters (CTCs) from breast cancer patients. To date, studies focusing on the expression of various desmosomal proteins in a variety of primary cancer types have shown both tumour-suppressive and tumour-promoting effects relating to tumour growth and metastasis. Our research group has recently identified Desmocollin-2 (DSC2) as an unfavourable prognostic marker in triple negative breast cancer (TNBC) patients. Moreover, high DSC2 levels in this patient subgroup is associated with an increased development of lung and brain metastases. In the current project, we aim to elucidate the molecular mechanisms behind these findings. Using genetically modified TNBC cell lines with DSC2high and DSC2low expression levels, along with 3D in vitro models, we are currently analysing the impact of DSC2 on tumour cell proliferation, aggregation and chemosensitivity. Furthermore, we are investigating the associated metastatic potential in a brain metastasis mouse model.

Peritoneal Metastasis in Ovarian Cancer

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MOLECULAR CHARACTERISTICS AND TUMORIGENICITY OF ASCITES-DERIVED TUMOR CELLS IN OVARIAN CANCER: MITOCHONDRIA METABOLISM AS A NOVEL THERAPY TARGET IN OVARIAN CANCER

Scientist involved in the project: Y. Ding, L. Oliveira-Ferrer, B. Schmalfeldt

Cooperation partners: V. Labitzky, C. Stürken (Institute of Anatomy und Experimental Morphology)

Project description: Ovarian cancer (OvCa) disseminates principally in the peritoneal cavity. Here, detached tumor cell aggregates (spheroids) from the primary tumor are regarded as “metastatic units”, which exhibit a low sensitivity to classical chemotherapy, probably due to their unique molecular characteristics and the influence of the ascites microenvironment. The high metastatic potential of these cell-aggregate structures could be confirmed by our group, where ascites-derived spheroids (>30µm) from high-grade serous OvCA (HGSOC) patients -which were confirmed tumor cells-enriched by flow cytometry (EpCAM+/CD24+)- successfully develop peritoneal carcinosis in an intraperitoneal mouse model. Using RNAseq analysis of ascites-derived tumor cells versus tumor tissue-derived cells, we identified several deregulated factors and cellular pathways that might be responsible for the high metastatic potential and the low chemotherapy sensitivity of ascites-spheroids. Currently, our studies aim to validate the potential role of these factors as new potential treatment options in advanced ovarian cancer.

E-Cadherin fragmentation

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THE FUNCTIONAL RELEVANCE OF E-CADHERIN FRAGMENTS IN OVARIAN CANCER PROGRESSION

Scientist involved in the project: K. Legler, S. Kürti, L. Oliveira-Ferrer, B. Schmalfeldt

Project description: In Epithelial Ovarian Cancer (EOC), metastasis occurs mainly intraperitoneal and retroperitoneal, while extra-abdominal metastases are a rarity. So far, the molecular mechanisms of the two main metastatic pathways are poorly understood. The cell adhesion molecule E-cadherin and precisely its fragment E-cadherin-85kDa could be identified as a molecular marker for intraperitoneal metastasis in EOC (Trillsch et al. Br J Cancer 2016). In the context of the actual project we aim to gain further insight into the Calpain-mediated E-cadherin fragmentation, and its modulation as a possible therapeutic target for the treatment of metastatic EOC. Using two calpain inhibitors, functional assays such as tumor cell proliferation, migration and chemosensitivity are performed in vitro. Additionally, we examine the impact of Calpain inhibition on tumor progression and metastasis in an intraperitoneal ovarian cancer mouse model.

Funding: Erich und Gertrud Roggenbuck-Stiftung

Intra- and Retroperitoneal Metastasis

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INTRA- UND RETROPERITONEAL METASTASIS IN OVARIAN CANCER: TWO BIOLOGICALY DIFFERENT TUMOR TYPES?

Scientist involved in the project: K. Legler, S. Kürti, A. Volk, L. Oliveira-Ferrer, B. Schmalfeldt

Project description: Epithelial Ovarian Cancer (EOC) disseminates mainly intraperitoneal and/or retroperitoneal (lymphatic), while distant metastases are rarely seen. So far, the biologic background of these two different modes of progression is poorly understood. Recent studies have shown that the EMT (epithelial-mesenchymal-transition) stage may influence the route of metastases in ovarian cancer. Our group could show that strong tumor expression of the 85 kDa E-Cadherin fragment is associated with intraperitoneal metastasis in EOC, whereas high levels of VEGF-C and VEGF-D correlate with retroperitoneal tumor dissemination. VEGF-C and –D are members of the vascular endothelial growth factor (VEGF) family and promote lymphangiogenesis by binding their cognate receptor VEGFR3 on lymphatic endothelial cells. We could also show that high levels of angiopoietin-2 (Ang2) are associated with retroperitoneal metastasis in EOC. Angiopoietin-2 is a vascular growth factor that play a role in angiogenesis. Targeting Ang2 via specific blocking antibodies has been shown to decrease metastasis to lymph nodes. In the context of this project we aim to establish molecular markers that help us identify patients with high risk of lymphatic metastases, who might benefit from systemic lymphadenectomy and specific antiangiogenic therapy.

Ascties-derived spheroids

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COMPARATIVE ANALYSIS OF 3D-MICROTUMORS OF OVARIAN CANCER PATIENTS AND FUNCTIONAL IN VITRO TESTING OF IMMUNOTHERAPEUTIC APPROACHES

Involved scientists of the clinic: Y. Ding, L. Hell, L. Oliveira-Ferrer

Cooperation partners: T. Sturmheit (2cureX GmbH), J. Wellbrock, W. Fiedler (II. Medical Clinic)

Project description: Every year almost 10.000 women are diagnosed with ovarian cancer in Germany. Since most patients are diagnosed at advances stages and recurrence of disease is frequent, the 5-year-survival rate is currently below forty percent. Debulking surgery followed by adjuvant chemotherapy constitutes the standard of care but alternative treatment options, such as immune checkpoint therapy, are already being evaluated in (pre-)clinical trials. Within the realm of this project, 3D-microtumors derived from solid tumor tissue and ascites of ovarian cancer patients are compared regarding their cellular composition, plasticity and protein expression of checkpoint molecules with potential immunotherapeutic relevance, e.g. PD-L1, TIGIT ligands. By doing so, we will gain a deeper understanding of relevant target structures for immunotherapeutic interventions. Additionally, we are planning to measure, quantify and compare the individual responses of patient-derived microtumors to different checkpoint inhibitors upon co-culture with autologous immune cells from solid tumor tissue, ascites or peripheral blood. Ultimately, we aim to develop a functional assay system for pre-therapeutic testing of checkpoint inhibitors and combinatorial approaches for patients suffering from ovarian cancer.

Funding: BMBF KMU-innovativ: Medizintechnik