gms | German Medical Science

Progression of head neck squamous cell cancer (HNSC) remains regional for long time and metastases develop only in late stages of the disease. Real time imaging of local invasion and the lymphatic dissemination have critical importance for a better understanding of the underlying processes.

To study cancer cell dynamics in vivo the human HNSC cell line FADU was transfected with different mammalian expression vectors encoding different fluorescent proteins. FADU cells were transfected using different vectors. All vectors contain immediate early promoter of CMV for protein expression and SV40 origin for replication in mammalian cells. G418 resistance allows selecting stable transformants. Transfected cells were xenotransplanted into nude mice. Visualization of tumor growth was performed using flat panel volumetric computed tomography (fpVCT). In vivo cell trafficking of HNSC cells was observed by the new imaging system OV100 (Olympus).

All mice developed HNSC- tumours within 14 days after transplantation. The high spatial resolution of the fp-VCT system can be used to accurately determine solid tumor volume, thus allowing for earlier assessment of the therapeutic response. TurboGFP and KATUSHKA showed brighter fluorescence due to extra fast protein expression allowing earlier signal detection compared to eGFP and DsRED. Single labeled HNSC cells could be observed in real time using an abdominal skin flap in nude mice. We established a model to study HNSC cells in vivo and describe tools for early online recognition of HNSC cancer. In vivo cell trafficking gave evidence for the behaviour of tumor cells. Combining molecular and imaging technologies will now enable further understanding of the molecular mechanisms and provide visible targets for drug development.