Radiation-resistant and repair-proficient human tumor cells may be associated with radiotherapy failure in head- and neck-cancer patients.

Abstract

Inherent cellular radioresistance and repair of x-ray damage was studied in 19 early-passage squamous cell carcinoma lines derived from head-and neck-cancer patients with known clinical results following radiotherapy. Human tumor cells that were radioresistant and/or proficient in accumulation/repair of x-ray damage were cultured from patients unsuccessfully treated with radiotherapy. Thus, the presence of radiation-resistant and repair-proficient tumor cells was associated with clinical radiation failure, suggesting the possibility of a predictive assay based on in vitro radiobiological parameters.

p38 MAPK Mediates γ-Irradiation-induced Endothelial Cell Apoptosis, and Vascular Endothelial Growth Factor Protects Endothelial Cells through the Phosphoinositide 3-Kinase-Akt-Bcl-2 Pathway

“…Radiotherapy is one of the most widely used cancer treatments, but it is often unsuccessful because of the acquisition of radioresistance by tumor cells and vascular endothelial cells (29,30). The mechanisms by which tumor cells and endothelial cells lining the tumor blood vessels acquire resistance to radiotherapy are poorly understood.…”

p53 mediated sensitization of squamous cell carcinoma of the head and neck to radiotherapy

“…Human head and neck cell lines JSQ-3, derived from a tumor of the nasal vestibule (Weichselbaum et al, 1988), SQ-20-B, derived from a squamous cell carcinoma of the larynx (Weichselbaum et al, 1986) and SCC61 derived from an oral (tongue) tumor (Weichselbaum et al, 1986) were generous gifts from Dr Ralph Weichselbaum, University of Chicago. These cell lines along with human non-cancerous skin ®broblast cell line H500, were maintained in Minimum Essential Medium with Earle's salts (EMEM), supplemented with 10% heat-activated fetal bovine serum; 50 mg/ml each of penicillin, streptomycin and neomycin; 2 mM L-glutamine; 0.1 mM non-essential amino acids and 1 mM sodium pyruvate.…”

A correlation between nuclear supercoiling and the response of patients with bladder cancer to radiotherapy

“…These lines were derived from patients with tumours of the head and neck who had failed conventional radiotherapy treatment and the lines now exhibit a substantial difference in radiosensitivity (Weichselbaum et al, 1986 (Gordon et al, 1990). Forward scatter histograms of nucleoids from control and irradiated cells for one patient are shown in Figure 1.…”