biostudies-literatureUnknown13(1)Mohamed BMCirculating tumour cells (CTCs) are a critical intermediate step in the process of cancer metastasis. The reliability of CTC isolation/purification has limited both the potential to report on metastatic progression and the development of CTCs as targets for therapeutic intervention. Here we report a new methodology, which optimises the culture conditions for CTCs using primary cancer cells as a model system. We exploited the known biology that CTCs thrive in hypoxic conditions, with their survival and proliferation being reliant on the activation of hypoxia-inducible factor 1 alpha (HIF-1α). We isolated epithelial-like and quasi-mesenchymal CTC phenotypes from the blood of a cancer patient and successfully cultured these cells for more than 8 weeks. The presence of CTC clusters was requireScientific reports3704https://www.ebi.ac.uk/biostudies/studies/S-EPMC9988863biostudies-literatureEx vivo expansion of circulating tumour cells (CTCs).PMC9988863O'Leary JJSelemidis SKelly TBates MGallagher MHeffernan SSaadeh FABrooks DAGleeson NMohamed BMMartin CSpillane CDKennedy JNorris LO'Toole SBrooks RDWard MPfalseEx vivo expansion of circulating tumour cells (CTCs).Circulating tumour cells (CTCs) are a critical intermediate step in the process of cancer metastasis. The reliability of CTC isolation/purification has limited both the potential to report on metastatic progression and the development of CTCs as targets for therapeutic intervention. Here we report a new methodology, which optimises the culture conditions for CTCs using primary cancer cells as a model system. We exploited the known biology that CTCs thrive in hypoxic conditions, with their survival and proliferation being reliant on the activation of hypoxia-inducible factor 1 alpha (HIF-1α). We isolated epithelial-like and quasi-mesenchymal CTC phenotypes from the blood of a cancer patient and successfully cultured these cells for more than 8 weeks. The presence of CTC clusters was require2023-01-01T00:00:00Z2023 Mar2025-04-21T19:47:13.818Z2025-04-05T17:43:24.968ZS-EPMC99888633687900310.1038/s41598-023-30733-6