Development of a circulating tumour cell culture model from head and neck squamous cell carcinoma

Despite the advancements made in the diagnosis and treatment of head and neck squamous cell carcinoma (HNSCC), metastasis remains the primary cause of cancer‐related deaths. Circulating tumour cells (CTCs) may offer a valuable platform for personalised treatment selection. Towards this goal, the establishment of short‐term CTC cultures would allow ex vivo characterisation and drug sensitivity testing. A negative enrichment technique (RosetteSep™, Human CD45 depletion cocktail) was used to capture CTCs for downstream culturing. Whole‐exome sequencing was applied to compare the genomic features in primary tumour and CTC cultures. In vitro functional assays and in vivo mouse models were used to confirm the origin and biological properties of cultured CTCs. Cytotoxicity assays were used to measure CTCs’ responsiveness to chemotherapeutic drugs. We successfully derived 16 CTC cell lines from HNSCC patients’ blood samples (16/107). Tumoural p16‐positivity notably increased the successful culture rate. CTC cultures displayed similar migratory and invasive capabilities compared to the American Type Culture Collection HNSCC cell lines. In addition, CTC cultures generated a subcutaneous tumour in immunocompromised NSG mice, which was confirmed by a pathologist to be of HNSCC. CTCs derived from post‐treatment blood samples showed a trend towards reduced sensitivity to Cisplatin and 5‐fluorouracil, although this did not reach statistical significance (Mann–Whitney test, p > .05). HNSCC‐derived CTC cultures closely recapitulate the features of primary tumours, providing a model system for in vitro drug testing and may pave the way towards a personalized medicine approach for HNSCC.