title: Radiosensitization of human tumor cells by gemcitabine in vitro.
abstract: Gemcitabine is a novel nucleoside analog that has shown clinical activity in a variety of solid tumors. The use of gemcitabine in combination with radiation was investigated in vitro using HT-29 colon carcinoma cells. Gemcitabine was demonstrated to be a potent radiosensitizer even at noncytotoxic concentrations. Increasing the concentration of gemcitabine and/or the duration of exposure increased the radiosensitization of cells. Biochemical studies indicated that a reduction in the dATP pool was the most likely mechanism of radiosensitization by gemcitabine. This effect is of great clinical importance and should be investigated in vivo.
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D002851:Chromatography, High Pressure Liquid; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003845:Deoxycytosine Nucleotides / Q000378:metabolism; D003854:Deoxyribonucleotides / Q000378:metabolism; D019073:HT29 Cells / Q000187:drug effects* / Q000528:radiation effects*; D006801:Humans; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D000093542:Gemcitabine
chemical_list: D003845:Deoxycytosine Nucleotides; D003854:Deoxyribonucleotides; D011838:Radiation-Sensitizing Agents; D003841:Deoxycytidine; D000093542:Gemcitabine