TY - JOUR AB - The search for agents that enhance the effect of ionizing radiation has been an object of study for decades. In this study, the sensitizing properties of cyclopentenylcytosine (CPEC) on radiation and cisplatin-induced radiosensitization in human squamous lung carcinoma cells were investigated. Human lung tumour SW-1573 cells (SWp, parental; SWg, gemcitabine-resistant) were incubated with CPEC and cisplatin and subsequently irradiated with different doses of γ-rays. Clonogenic survival was determined to measure the effectiveness of the treatments. CPEC (1 or 2 µM) treatment for 4 h decreased the plating efficiency to 75 and 50% in SWp and SWg cells, respectively. In the SWg cells, 0.1 and 1 µM CPEC for 4 h enhanced the cell killing effect of cisplatin. However, an increase was not noted in the SWp cells. Due to the moderate toxicity of 1 µM for 4 h, this CPEC dose was used in the radiosensitization experiments. However, CPEC neither radiosensitized the lung tumour cells nor enhanced the radiosensitizing effect of cisplatin. A 2-h incubation with 4 µM cisplatin also decreased the plating efficiency to 75-80% in the two cell lines. Using this cisplatin dose, radiosensitization was obtained in the two cell lines. Although cisplatin treatment clearly radiosensitized the lung tumour cells, CPEC treatment did not. Cisplatin-induced radiosensitization was also not enhanced by CPEC. AD - Laboratory for Experimental Oncology and Radiobiology (LEXOR), Department of Radiation Oncology, Center for Experimental Molecular Medicine, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands null AU - Rodermond,Hans,M. AU - ten Cate,Rosemarie AU - Haveman,Jaap AU - van Kuilenburg,André AU - Medema,Jan,P. AU - van Bree,Chris AU - Franken,Nicolaas,A.P. DA - 2010/05/01 DO - 10.3892/ol_00000095 EP - 540 IS - 3 JO - Oncol Lett PY - 2010 SN - 1792-1074 1792-1082 SP - 537 ST - Cyclopentenylcytosine does not enhance cisplatin-induced radiosensitization in human lung tumour cells T2 - Oncology Letters TI - Cyclopentenylcytosine does not enhance cisplatin-induced radiosensitization in human lung tumour cells UR - https://doi.org/10.3892/ol_00000095 VL - 1 ER -