Inhibition of radiation-induced transformation in vitro by bacterial endotoxins.
Bacterial endotoxins (lipopolysaccharides) were found to suppress X-ray-induced malignant transformation of C3H/10T1/2 cells. Endotoxins were effective if present either throughout the 6-week transformation assay period, or for the final 4-week phase, but not when present only for the initial 2-week phase. Neither growth nor survival of C3H/10T1/2 cells, or a radiation-transformed cell line derived from them, were affected by endotoxins. Also, the endotoxins did not affect the formation of foci by the radiation transformed cells when these cells were co-cultured with untransformed cells. These results suggest that endotoxins exert their effect directly upon the transformation process itself, perhaps at a 'late' step in the conversion of an untransformed to a transformed cell.
Carew
J A
JA
Laboratory of Radiobiology, Harvard School of Public Health, Boston, MA 02115.
Collins
M F
MF
Kennedy
A R
AR
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000494:pharmacology*; D051379:Mice
D004731:Endotoxins