Jan Paul Medema studied Chemistry in Leiden and performed his PhD studies at the Univeristy of Utrecht analyzing the role of  the Ras GTPase GAP120 in differentiation of keratinocytes. During his first postdoctoral years at the German Cancer Center in Heidelberg he worked on the signal transduction cascade induced by CD95/Fas/APO-1 and used this insight in cancer immunology during his postdoc at the LUMC in Leiden. Here he became assistant and subsequently associate Professor focussing more and more on the role of cell death escape mechanisms that tumors use to avoid immune surveilance and help escape from chemotherapy. In 2005 he moved to the AMC in Amsterdam to start the laboratory of Experimental Oncology and Radiobiology (LEXOR) and became full Professor, department head and in 2016 Scientific director of the Cancer Center Amsterdam. His laborotory LEXOR now houses multiple research teams that study cancers of the gastrointestinal tract, specifically colorectal, esophageal and pancreatic cancer. The aim is to understand the heterogeneity present within these cancers and between distinct cancer patients. For colorectal cancer we have been instrumental in the design of molecular subtypes that identify patient groups with clearly distinctive tumors from a biological point of view. Understanding the ontogeny, molecular wiring and vulnerabilities of these molecular subtypes is key to our research program.

Next to this patient-to-patient variation we study the intra-tumor heterogeneity from a cancer stem cell perspective. Interaction with the microenvironment, nutrients, microvasculature and immune components is part of our studies to unravel biological wiring as well as novel targets for therapy.

For our studies we depend on primary tumor material from patients and hence we have optimal connection to several clinical departments (Surgery, Pathology, Radiotherapy, Med Oncology and Gastroenterology). Moreover, organoids and xenografts derived from tumor material as well as a wide range of mouse models is part of our research infrastructure.

Focus points

• Colon Cancer, prognosis, novel therapies and therapy resistance
• Colon Cancer Subtypes
• Apoptosis/Cell death mechanisms
• Radiation damage

Experimental Oncology and Radiobiology

Colorectal Cancer Biology and Treatment