Morphological approach of radiation induced DNA strand breakage by immunodetection of poly (ADP-ribose) polymerase (PARP): an in vitro study of human oligodendrogliomas

Poly (ADP-ribose) polymerase (PARP) is a nuclear enzyme encompassing two zinc finger motifs wich specifically binds to radiation induced DNA strand breaks. We develop a new immune-labelling of poly ADP-ribose wich coupled together with the immunodetection of cells in cycle with MIB1, permits to detect and quantify the DNA fragmentation induced by gamma radiations (Cesium(137)). This method, applied to organotypical cultures of human oligodendroglioma, submitted to gamma radiation, a dose dependant nuclear signal. This one increased significantly in the presence of a radiosensitizer like iododeoxyuridine (IUDR 5 mu g/ml). This poly ADP-ribose immunodetection can be useful, to detect furtherly the individual radiosensitivity of human glioma.