Metabolic rearrangements subsequent to malignant transformation are not well characterized in endometrial cancer (EC). Identification of altered metabolites could facilitate imaging-guided diagnosis, treatment surveillance and help to identify new therapeutic options. Here we employed high resolution-magic angle spinning magnetic resonance mass spectroscopy on EC surgical specimens and normal endometrial tissue to investigate key modulators that might explain metabolic changes, incorporating additional investigations using qRT-PCR, Western blotting, tissue microarrays and uptake assays of [3H]-labeled choline. Lipid metabolism was severely dysregulated in EC with various amino acids, inositols, nucleobases and glutathione also altered. Among the most important lipid-related alterations was increased phosphocholine levels (increased 70% in EC). Mechanistic investigations revealed that changes were not due to altered choline transporter expression, but rather increased expression of choline kinase α (CHKA) and an activated deacylation pathway, as indicated by upregulated expression of the catabolic enzymes LYPLA1, LYPLA2 and GPCPD1. We confirmed the significance of CHKA overexpression on a tissue microarray including a large series of endometrial hyperplasia, atypical hyperplasia and adenocarcinoma tissues, supporting a role for CHKA in malignant transformation. Lastly, we documented several-fold increases in the uptake of [3H]choline in endometrial cancer cell lines compared to normal endometrial stromal cells. Our results validate deregulated choline biochemistry as an important source of non-invasive imaging biomarkers for EC.


