Radiosensitization of EMT6 cells by four platinum complexes

Journal Article · Wed May 01 04:00:00 EDT 1985 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(85)90116-6· OSTI ID:5444931

Teicher, B A; Rockwell, S; Lee, J B

The compounds described here are dichloro complexes of bivalent platinum with one or two potentially radiosensitizing ligands. The radiosensitization of oxygenated and hypoxic exponentially growing EMT6 cells in vitro was measured. The dose modifying factors obtained with 200 ..mu..M and 400 ..mu..M trans-bis(2-nitroimidazole)dichloroplatinum II (NIPt) in hypoxic cells were 1.5 and 2.1, respectively. For trans-bis(2-amino-5-nitrothiazole)dichloroplatinum II (Plant) under the same conditions, the dose modifying factor was 1.5 at 200 ..mu..M and 1.8 at 400 ..mu..M. Neither compound sensitized oxygenated cells when tested similar protocols. Unlike the trans complexes (1,2-diamino-4-nitrobenzene)dichloroplatinum II (Plato) was cytotoxic toward the hypoxic cells in the absence of X rays. The time course of cytotoxicity for 100 ..mu..M Plato in exponentially growing cells showed rapid killing of hypoxic cells, and much less toxicity toward oxygenated cells. In radiosensitization studies, dose modifying factors of 1.6 and 2.0 were found with 200 ..mu..M and 400 ..mu..M Plato in hypoxic cells. The compound did not sensitize aerobic cells. The well-known platinum complex cis-dipyridinedichloroplatinum II (PyPt) represents a cis-platinum heterocyclic aromatic complex that does not have a nitro-functionality. The dose modifying factor obtained with 400 ..mu..M PyPt in hypoxic cells was 1.7. On a molar basis, the nitro-functional platinum complexes appear to be more effective as hypoxic cell radiosensitizers than the corresponding free ligands.

• Research Organization: Dana-Farber Cancer Institute, Boston, MA
• OSTI ID: 5444931
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 11:5; ISSN IOBPD
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANOXIA
CELL KILLING
COMPLEXES
DATA
ELECTROMAGNETIC RADIATION
ELEMENTS
EXPERIMENTAL DATA
IN VITRO
INFORMATION
IONIZING RADIATIONS
NONMETALS
NUMERICAL DATA
OXYGEN
PLATINUM COMPLEXES
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RESPONSE MODIFYING FACTORS
SURVIVAL CURVES
TRANSITION ELEMENT COMPLEXES
TUMOR CELLS
X RADIATION