Effects of cisplatin and gamma-irradiation on cell survival, the induction of chromosomal aberrations and apoptosis in SW-1573 cells.
OBJECTIVE
Cisplatin was found to radiosensitize SW-1573 cells by inhibition of PLDR. Therefore, it was investigated whether cisplatin combined with gamma-radiation leads to an increase in the number of chromosomal aberrations or apoptotic cells compared with radiation alone.


METHODS
Confluent cultures of the human lung carcinoma cell line SW-1573 were treated with 1 microM cisplatin for 1 h, 4 Gy gamma-radiation, or a combination of both. Cell survival was studied by the clonogenic assay. Aberrations were analysed by FISH in prematurely condensed chromosomes (PCC) and the induction of apoptosis by counting fragmented nuclei.


RESULTS
A radiosensitizing effect of cisplatin on cell survival was observed if time for PLDR was allowed. An increased number of chromosomal fragments were observed immediately after irradiation compared with 24 h after irradiation whereas color junctions are only formed 24 h after irradiation. No increase in chromosomal aberrations was found after combined treatment, but a significantly enhanced number of fragmented nuclei were observed when confluent cultures were replated after allowing PLDR.


CONCLUSIONS
The inhibition of PLDR by cisplatin in delayed plated SW-1573 cells did not increase chromosomal aberrations, but increased the induction of apoptosis.
Bergs
J W J
JW
Academic Medical Center, University of Amsterdam, Department of Radiotherapy, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. j.w.bergs@amc.uva.nl
Franken
N A P
NA
ten Cate
R
R
van Bree
C
C
Haveman
J
J
D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002869:Chromosome Aberrations / Q000139:chemically induced* / Q000528:radiation effects*; D002945:Cisplatin / Q000633:toxicity*; D005720:Gamma Rays; D006801:Humans; D011838:Radiation-Sensitizing Agents / Q000633:toxicity
D011838:Radiation-Sensitizing Agents; D002945:Cisplatin