DNA excision repair was measured in cultured human fibroblasts after single or dual treatments with ultraviolet radiation, 4-nitroquinoline 1-oxide, or N-acetoxy-2-acetylaminofluorene. Three approaches were used to monitor repair: unscheduled DNA synthesis, measured by autoradiography; repair replication, measured by the incorporation of a density-labeled DNA precursor into repaired regions; an...

Confluent LLC-PKi cells express many characteristics of renal prox imal tubule epithelia. We report here the use of this cell line to investigate the possible mechanisms of m-diamminedichloroplatinum(II) (1)1)1')induced nephrotoxicity and diethyldithiocarbamate (DDTC) ameliora tion. Cells were exposed to platinum-based drug for l h and then incubated in drug-free medium until assayed. There was...

UV light induces DNA lesions, which are removed by nucleotide excision repair (NER). Exonuclease 1 (EXO1) is highly conserved from yeast to human and is implicated in numerous DNA metabolic pathways, including repair, recombination, replication, and telomere maintenance. Here we show that hEXO1 is involved in the cellular response to UV irradiation in human cells. After local UV irradiation, fl...

Rothmund Thomson syndrome is a rare autosomal recessive skin disorder. The main clinical feature is poikiloderma appearing in early childhood associated with skeletal abnormalities. Early occurrence of malignancies is another relevant feature. Here we describe the clinical features of 2 patients with Rothmund Thomson syndrome who were investigated for the in vitro DNA repair capacities of blood...

Fibroblastoid Chinese hamster cells synchronized by mitotic selection were microirradiated in G1, using a low power laser-UV-microbeam (2 = 257 nm). The incident e?ergy was either concentrated on a small part of the nucleus (mode 1) or distributed over the whole nucleus (mode 11). Using the same incident UV energy, the local UV fluences were estimated to differ by two orders sf magnitude. Follo...

Previously, it was implicated that p53 plays a role in spermatogenesis. Here we report that p53 knockout mice exhibit significantly less mature motile spermatozoa than their p53(+/+) counterparts. To better understand the role of p53 in spermatogenesis, we analyzed the response of spermatogenic cells to DNA insult during prophase. It was found that although low-level gamma-irradiation activated...