Rhabdoid tumor cells targeted through their building blocks

Marjolein Kes has identified new therapeutic targets for the treatment of rhabdoid tumors (MRT). In the laboratory, Kes found that inhibiting the production of DNA building blocks slows the division of tumor cells and can even cause them to disappear. These findings form the basis for the development of a new clinical study. Yesterday, she received her PhD from Utrecht University. She defended her thesis on 10 June 2026 at the Faculty of Veterinary Medicine at Utrecht University.

MRT is a rare but difficult-to-treat tumor. Despite intensive treatments, outcomes remain limited for some children. Researchers are therefore searching for new ways to target tumor cells.

Marjolein Kes investigated how these cancer cells use nutrients to grow and which parts of this process contain vulnerabilities that make tumor cells susceptible when disrupted. She conducted this research within the group of Jarno Drost at the Princess Máxima Center and the group of Celia Berkers at Utrecht University.

Using a range of research techniques, Kes studied mini-tumors grown in the laboratory, also known as organoids. Tumor tissue obtained from the biobank of the Máxima Center was used for this work. In the laboratory, she found that inhibiting the production of DNA building blocks, including by targeting the enzyme DHODH, reduces the growth of cancer cells. 

From discovery to application 

Following completion of her PhD, Kes will continue working at the Máxima Center. She will be further investigating the existing drug gemcitabine, which acts on the same metabolic process identified during her laboratory research. In addition, the Máxima Center is currently developing a clinical study involving gemcitabine.

"What I like most about this research is that it has led to concrete next steps for children. We have identified new vulnerabilities that may contribute to better treatments for children with rhabdoid tumors", Kes says.