The interaction of 5-fluorouracil, hydroxyurea, and radiation in two human head and neck cancer cell lines.
We have investigated the effects of 5-fluorouracil (5-FU) and hydroxyurea (HU) with radiation on two human head and neck squamous carcinoma cell lines. SQ-20B has a D0 of 239 cGy and an S phase fraction of 37%, while SQ-38 has a D0 of 146 cGy and an S phase fraction of 31%. For SQ-20B the surviving fraction at 100 cGy was significantly reduced (p < 0.05) when cells were exposed to HU or to 5-FU or both chemotherapy agents together with radiation. No significant effect was seen for SQ-38 with either chemotherapy agent alone or in combination with radiation as compared with radiation alone. Therefore, additive cytotoxicity between 5-FU and HU and radiotherapy was observed only in a head and neck cancer cell line with a higher D0 and a higher S phase fraction.
Vokes
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EE
Department of Medicine, University of Chicago Medical Center, Ill 60637-1470.
Beckett
M
M
Karrison
T
T
Weichselbaum
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RR
D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003131:Combined Modality Therapy; D005472:Fluorouracil / Q000494:pharmacology*; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000628:therapy; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology*; D016196:S Phase / Q000187:drug effects / Q000528:radiation effects; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects
D005472:Fluorouracil; D006918:Hydroxyurea