Purpose: To examine the rationale of including a hypoxic cell sensitizer (2-methoxyestradiol, 2ME2) in an alternative regimen for human head and neck cancer that involves accelerated hyperfractionated radiation. It is believed that hypoxia may increase radiation-induced cell killing, partly because the hypoxic cell sensitizer stabilizes the p53 tumor suppressor gene. The rationale of using 2ME2 in combination with accelerated hyperfractionated radiation is supported by earlier clinical data that demonstrated a superior clinical efficacy of this regimen compared to 5-FU/bleomycin/radiation. The combination of 2ME2 with tunotuolized accelerated hyperfractionated radiation should therefore be of interest to cancer patients who in principle could benefit from this promising new combination.
Purpose: To examine the factors that influence repopulation kinetics in hypoxic cell sensitizers combination with X-ray irradiation in an hSCC cell line. The concept of combining a hypoxic cell sensitizer and reoxygenation has previously been shown to be of interest for sequence dependent therapy with accelerated hyperfractionated radiation regimes. This project addresses a step that has been left out, namely how to better select tumor cell proliferation for such approaches, alternatively, to identify other factors that influence repopulation.
Purpose: The purpose of this study was to examine the radiosensitivity of cancer stem cells isolated from human HNSCC and breast cancer tumors. The tumour-initiating cells (TIC) were isolated by magnetic cell sorting based cell culture of single cells from tumor cell suspension. Then, the differences in sensitivity between TIC and NSC (nonspecific cancer stem cells) were tested with a low dose irradiation (0.1 to 5 Gy) in ice-cold medium during cultivation. The differences in radiosensitivity were tested with a clonogenic assay. The differences in radiosensitivity were tested between TIC and NSC on the same day. The distinct radiosensitivity changes at different passages were tested for NSC. The Radiosensitivity in TIC could rapidly increase within 1 week after isolation of the cells. d2c66b5586