Ex vivo expansion of circulating tumour cells (CTCs)
Bashir M. Mohamed, Mark P. Ward, Mark Bates, Cathy D. Spillane, Tanya Kelly, Cara Martin, Michael Gallagher, Sheena Heffernan, Lucy Norris, John Kennedy, Feras Abu Saadeh, Noreen Gleeson, Doug A. Brooks, Robert D. Brooks, Stavros Selemidis, Sharon O’Toole, John J. O’Leary
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 required to establish and maintain long-term cultures. This novel methodology for the long-term culture of CTCs will aid in the development of downstream applications, including CTC theranostics.
