Poster Presentation 44th Lorne Genome Conference 2023

Exploitation of the UDP-glucose hydrolase NUDT22 as novel target in cancer therapy (#166)

Melanie Walter 1 2 , Oliver Mortusewicz 3 , Tobias Koolmeister 3 , Evert Homan 3 , Martin Scobie 3 , Ingrid Almloef 3 , Adam Throup 3 , Thomas Helleday 3 , Patrick Herr 1
  1. Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom
  2. Genome Integrity Unit, Children's Medical Research Institute, Westmead, NSW, Australia
  3. Science for Life Laboratory, Department of Oncology and Pathology, Karolinska Institute, Stockholm, Sweden

NUDT22 is a novel member of the NUDIX protein superfamily. Our previous work identified a specific substrate activity for NUDT22 towards uridine diphosphate (UDP)-glucose resulting in the generation of glucose 1-phosphate (G1P) and the pyrimidine precursor uridine monophosphate (UMP) [1]. NUDT22 expression levels are significantly increased in cancer and fast proliferating cells, such as cancer cells, can adapt the more energy-efficient nucleoside salvage pathways to maintain sufficient nucleotide pool levels for cell proliferation and DNA replication stress prevention [2,3]. We therefore hypothesised a specific and important role of NUDT22 in nucleotide salvage and the potential to exploit NUDT22 as novel anti-cancer target.

We assessed the effects of NUDT22 knockout on proliferation, nucleotide levels, DNA replication stress, DNA damage, DNA replication fork speed and cell cycle progression alone or in combination with pyrimidine de novo inhibition in cancer and non-cancer cells. We performed a xenograft study to determine a potential role of NUDT22 as cancer target in vivo. Furthermore, we exploited our NUDT22 co-crystal structure for the development of inhibitors in virtual screens, which we evaluated based on enzymatic activity and target engagement.

NUDT22 deficient cancer cells suffer from growth retardation, a reduction in nucleotide levels, DNA replication stress and DNA damage induction, S-phase delay and slower DNA replication fork speed. DNA replication stress and replication fork speed could be rescued by uridine supplementation supporting a specific role for NUDT22 in pyrimidine salvage. In addition, NUDT22 knockout sensitized cancer cells to pyrimidine de novo inhibition and reduces tumour growth in vivo.

In conclusion, we propose the discovery of a novel pyrimidine salvage pathway through NUDT22 controlling pyrimidine levels thereby preventing DNA replication stress and promoting cancer growth. Our in vitro and in vivo findings suggest NUDT22 as an emerging target for cancer therapy [3]. In addition, we identified potential NUDT22 inhibitors with direct target engagement [4].

  1. Carter, M.; Jemth, A.-S.; Carreras-Puigvert, J.; Herr, P.; Carranza, M.M.; Vallin, K.S.A.; Throup, A.; Helleday, T.; Stenmark, P. Human NUDT22 Is a UDP-Glucose/Galactose Hydrolase Exhibiting a Unique Structural Fold. Structure 2018, 26, 295-303.e6, doi:10.1016/j.str.2018.01.004.
  2. Walter, M., & Herr, P. (2022). Re-Discovery of Pyrimidine Salvage as Target in Cancer Therapy. Cells, 11(4), 739. https://doi.org/10.3390/cells11040739
  3. Walter, M., Mayr, F., Hanna, B. M. F., Cookson, V., Mortusewicz, O., Helleday, T., & Herr, P. (2022). NUDT22 promotes cancer growth through pyrimidine salvage and the TCA cycle. https://doi.org/10.21203/rs.3.rs-1491465/v1
  4. Walter, M., Homan, E., Koolmeister, T., Almlöf, I., Mortusewicz, O., Helleday, T., & Herr, P. (2021). Development of Small Molecule NUDT22 Inhibitors for Uses in Cancer. Medical Sciences Forum, 3(1), 1. https://doi.org/10.3390/iecc2021-09197