BACKGROUND: The correlation between telomerase activity and antitumor effects was investigated in cell lines of human gastric (MKN-28, MKN-45, and MKN-74) and breast (T-47D, MCF-7, ZR75-1) cancers to evaluate the possibility of utilizing this enzyme to predict tumor response to chemotherapy. MATERIALS AND METHODS: After culture with various concentrations of 5-fluorouracil (5-FU) or doxorubicin (DOX) for 3 days, cell viability (trypan blue exclusion), cell cycle distribution (flow cytometry), and telomerase (TRAP-EZE) were measured. RESULTS: Telomerase activity correlated significantly with the number of viable cells. After drug exposure, this activity decreased rapidly in a dose-dependent fashion in most cell lines. There was no correlation between telomerase activity and the distribution of cells in the cell cycle. CONCLUSIONS: As the assay for telomerase activity is extremely sensitive and is virtually specific to cancer cells, this method may prove useful for the sensitivity testing of small specimens of human tumors.
BACKGROUND: The correlation between telomerase activity and antitumor effects was investigated in cell lines of human gastric (MKN-28, MKN-45, and MKN-74) and breast (T-47D, MCF-7, ZR75-1) cancers to evaluate the possibility of utilizing this enzyme to predict tumor response to chemotherapy. MATERIALS AND METHODS: After culture with various concentrations of 5-fluorouracil (5-FU) or doxorubicin (DOX) for 3 days, cell viability (trypan blue exclusion), cell cycle distribution (flow cytometry), and telomerase (TRAP-EZE) were measured. RESULTS: Telomerase activity correlated significantly with the number of viable cells. After drug exposure, this activity decreased rapidly in a dose-dependent fashion in most cell lines. There was no correlation between telomerase activity and the distribution of cells in the cell cycle. CONCLUSIONS: As the assay for telomerase activity is extremely sensitive and is virtually specific to cancer cells, this method may prove useful for the sensitivity testing of small specimens of humantumors.