Thomas Dittmar

Thomas Dittmar is Professor of Immunology and Tumour Biology and Chairman of the Dr . med./ Dr. rer. medic. doctoral committee.

The Chair of Immunology and Tumour Biology investigates how the fusion of cells influences the development and growth of cancer in humans. The fusion of healthy human cells as well as the fusion of tumour and stem cells with immune cells, connective tissue cells and adult stem cells is investigated.

These investigations open up new perspectives on the development of tumour hybrid cells, which have previously unknown biological properties, such as the transformation of healthy cells into cancer cells, the formation of metastases and the occurrence of relapses.

At the same time, the scientists are investigating how the fusion of cells changes the cell behaviour within a tumour. They are analysing the tumour hybrid cells and investigating the mechanisms involved in cell fusion. These findings could lead to new approaches in cancer therapy.

The professorship is also investigating how micro- and nanoplastic particles influence healthy human cells and cancer cells. They are particularly interested in whether and how these tiny plastic particles can increase the risk of developing cancer or promote tumour growth. The Professorship of Immunology and Tumour Biology is part of the Centre for Biomedical Education and Research (ZBAF).
 

The Chair of Immunology and Tumour Biology conducts basic, translational and clinical research. There are two working groups.

The "Stem Cells" working group is primarily concerned with the role of cell fusion in tumour development. It is known that tumour cells can fuse with tumour or normal cells, but also with each other. This can result in hybrid cells with new properties. These include, for example, increased resistance to chemotherapeutic agents or an increased metastatic potential. It is also known that the homologous fusion of normal cells can give rise to hybrid cells with neoplastic potential.

In in-vitro studies, the research group has already been able to show that cells created by the fusion of healthy breast cells and breast cancer cells are more resistant to certain anti-cancer drugs (cytostatics). In addition, the hybrid cells, but not the original cells, responded to the chemokine CCL21, which is associated with lymph node metastasis of breast tumours.

In recent years, the research group has also investigated the question of why tumour cells combine with other cells (e.g. stem cells). The scientists have developed analysis tools such as the double fluorescence reporter assay or the dual-split assay to investigate this phenomenon in more detail. They have discovered that the substance TNF-alpha causes the cells to connect more frequently. If patients are given the anti-inflammatory antibiotic minocycline, these connections occur less frequently. The connected cells (hybrid cells) may have cancer stem cell properties; they survive cancer therapies and can cause relapses. In current investigations, the researchers are looking at the role of the scramblase protein in the fusion of tumour cells with stem cells. They are also investigating whether normal cells can become malignant as a result of the fusion. Initial results indicate that this is indeed the case: among other things, the working group has observed a large number of chromosome distribution errors during cell division.

The Micro- and Nanoplastics working group is investigating the impact of micro- and nanoplastics on human cells, analysing both normal cells and cancer cells. The contamination of the environment and also of food by micro- and nanoplastics is caused by the increasing global consumption of plastic products in general and their disposal in nature/the environment. Plastic cannot (or can only very poorly) be broken down by microorganisms. Instead, erosion takes place through wind, water, soil, solar radiation, etc., which initially produces macroplastic particles and finally micro- and nanoplastic particles. These are absorbed by both plants and animals, thus entering the food chain and ultimately reaching humans. The fact is that micro- and nanoplastic particles are mainly absorbed through food and can accumulate in the body. Using in-vitro studies, we have already been able to show that micro- and nanoplastic particles are taken up in a dose-, size- and cell line-specific manner and have a possible influence on the migratory properties of the cells. We are currently investigating the mechanism by which the micro- and nanoplastic particles are taken up into the cells.

• Silvia Keil, Technical Assistant
• Dr rer. nat. Julian Weiler, Academic staff
• Dr rer. nat. Mareike Sieler, Research Assistant
• Vivienne Ogasa, M. Sc., Research Assistant
• Alexandra Brause, doctoral student
• Robin Hegman, doctoral student
• Maximilian Späth, doctoral student

since 2025
Holder of the Professorship for Immunology and Tumour Biology, Witten/Herdecke University

since 2018
Spokesperson for the Witten site of the Stem Cell Network.NRW

2018 - 2025
Acting Head of the Institute of Immunology, Witten/Herdecke University

since 2010
University professorship at the Institute of Immunology, Witten/Herdecke University

2009 - 2010
apl. professorship at the Institute of Immunology, Witten/Herdecke University

Since 2008
Spokesperson for the Witten site of the Competence Network Stem Cell Research NRW

2008 - 2017
Spokesperson for the Witten site of the Competence Network Stem Cell Research NRW (today: Stammzellnetzwerk.NRW)

since 2003
Head of the Stem Cell Working Group, Witten/Herdecke University

2003 - 2009
Junior Professorship for Tumour Immunology, Witten/Herdecke University

1999 - 2003
PostDoc position at the Institute of Immunology, Witten/Herdecke University

1999
Doctoral studies at the Institute of Immunology, Witten/Herdecke University

1995
Degree in Chemistry (Diplom), Ruhr University Bochum

The Chair of Immunology and Tumour Biology offers seminars and POL consultations (POL = problem-based learning) in the model degree programme in Medicine and the degree programme in Dentistry, Oral and Maxillofacial Medicine. She is also involved in teaching on the Biomedicine PhD programme at the Faculty of Health.

Interested students of medicine and dentistry can complete six-week laboratory research internships. Students are required to work on a small, independent research project. The project can also be used for academic staff work, which is planned in the 9th semester of the new model degree programme, and can also be linked to doctoral studies.