Thomas Helleday's Group

The Helleday group is continuously working towards developing novel targeted therapies out of basic science findings. The multidisciplinary translational research group is focusing on understanding basic DNA repair and DNA-damage signaling pathways as well as nucleotide metabolism and developing novel drugs for anti-cancer treatments, and for treating inflammation/autoimmunity and virus infections.

Thomas Helleday received his PhD from Stockholm University in 1999. He was appointed lecturer at University of Sheffield in 2000 and started his research groups at the Institute for Cancer Studies at University of Sheffield (UK), while in parallel kept a small research group at the Stockholm University (Sweden). In January 2007, he was recruited as professor of cancer therapeutics at the MRC/CRUK Institute for Radiation Oncology and Biology at University of Oxford and maintained a research group at the Stockholm University. In 2012, Prof Helleday was appointed to the Torsten and Ragnar Söderberg Jubilee Professorship of Translational Medicine and Chemical Biology at the Science for Life laboratory at the Karolinska Institutet (KI) in Sweden, which since 2018 is hosted by the Department of Oncology-Pathology, KI.

In 2018, Professor Helleday reestablished a laboratory in the UK as founding Director of the Weston Park Cancer Center at the University of Sheffield. Today Prof. Helleday shares his time between KI and Sheffield University.

The Helleday team was first to describe sensitivity of homologous recombination defective cancers (HRD, e.g., BRCA mutant) to PARP inhibitors (Helleday 2003 US8859562B2, Bryant et al., 2005 Nature 434, 913-7), exemplifying the synthetic lethal concept for treatment of cancer. Today, numerous PARP inhibitors are approved treatment for HRD ovarian and breast cancers, with pending regulatory approvals for prostate and pancreatic cancer. PARP inhibitors in BRCA mutated cancer showcase the synthetic lethal concept of cancer, a concept that many novel targeted therapies are using.

The Helleday group consists of two research teams (Helleday/ Rudd;). The Helleday/ team is further divided into basic science (Dr. Oliver Mortusewics); biochemistry & chemical biology (Dr. Ann-Sofie Jemth); in vitro pharmacology (Dr. Niklas Schultz); in vivo pharmacology (Dr. Kumar Sanjiv); medicinal chemistry (Dr. Martin Scobie); teams.

The two research teams are focused on:
- DNA repair and nucleotide metabolism (Thomas Helleday)
- Exploiting cancer cell metabolism to improve cancer treatment (Sean Rudd)

Research teams


The research aims to i) purifying and targeting proteins in DNA repair and metabolism, ii) use probes and genetic tools to increase basic knowledge around target proteins and iii) translating basic research findings into new treatments tested in clinic


The aim of our research is to rationally improve the treatment of cancer. With this focus, we investigate the role of metabolic pathways inside cancer cells and their involvement in cancer biology and therapy resistance, with a particular focus upon the pathways responsible for maintaining the DNA molecule and the DNA precursor pool.