DNA double-strand break rejoining rates, inherent radiation sensitivity and human tumour response to radiotherapy
| Autor: | Jeffrey L. Schwartz, Ralph R. Weichselbaum, Reba Mustafi, M.A. Beckett |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Cancer Research
Pathology medicine.medical_specialty DNA Repair Cell Survival DNA damage DNA repair medicine.medical_treatment Biology Radiation Tolerance Mice Radiation sensitivity Predictive Value of Tests Tumor Cells Cultured medicine Animals Humans Radiosensitivity Clonogenic assay Survival analysis integumentary system Sarcoma 3T3 Cells DNA Neoplasm Radiation therapy Oncology Epidermoid carcinoma Head and Neck Neoplasms Carcinoma Squamous Cell Cancer research DNA Damage Research Article |
| Zdroj: | British Journal of Cancer |
| ISSN: | 1532-1827 0007-0920 |
| DOI: | 10.1038/bjc.1996.312 |
| Popis: | The relationship between DNA double-strand break rejoining rates, inherent radiation sensitivity and tumour response to radiation therapy was determined for a group of 25 squamous cell carcinoma (SCC) and eight sarcoma (SAR) tumours. DNA double-strand break frequencies were measured by neutral filter elution in first passage following explant tumour samples after in vitro exposure to 100 Gy of 60Co gamma-rays. There was no significant difference between SCC and SAR tumour cells in their sensitivity to break induction, but in a 1 h time period SAR tumour cells rejoined significantly fewer breaks than SCC tumour cells, consistent with the greater sensitivity of SAR and suggesting that differences in rates of break rejoining account for the different distributions of radiosensitivities seen when different tumour types are compared. The percentage of breaks rejoined in 1 h in these tumour samples correlated well with D(o) and with the beta component of the survival curve, measured in vitro by clonogenic assay in tumour cell lines established from the tumour samples, but not with SF2 or the alpha component of the survival curve. The rates of DNA double-strand break rejoining therefore appear to influence the exponential portion of survival curves and probably the interactions between breaks. The percentage of breaks rejoined in 1 h was higher in SCC tumours that subsequently failed radiotherapy and, although the differences were not significant, they suggest that rates of break rejoining are an important component of tumour response to radiation therapy. |
| Databáze: | OpenAIRE |
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