Complementation of transformed fibroblasts from patients with combined xeroderma pigmentosum-Cockayne syndrome.
Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are human hereditary disorders characterized at the cellular level by an inability to repair certain types of DNA damage. Usually, XP and CS are clinically and genetically distinct. However, in rare cases, CS patients have been shown to have mutations in genes that were previously linked to the development of XP. The linkage between XP and CS has been difficult to study because few permanent cell lines have been established from XP/CS patients. To generate permanent cell lines, primary fibroblast cultures from two patients, displaying characteristics associated with CS and belonging to XP complementation group G, were transformed with anorigin-of-replication-deficient simian virus 40 (SV40). The new cell lines, summation operatorXPCS1LVo- and summation operatorXPCS1ROo-,were characterized phenotypically and genotypically to verify that properties of the primary cells are preserved after transformation. The cell lines exhibited rapid growth in culture and were shown, by immunostaining, to express the SV40 T antigen. The summation operatorXPCS1LVo- and summation operatorXPCS1ROo- cell lines were hypersensitive to UV light and had an impaired ability to reactivate a UV-irradiated reporter gene. Using polymerase chain reaction (PCR) amplification and restriction enzyme cleavage, the summation operatorXPCS1ROo- cells were shown to retain the homozygous T deletion at XPG position 2972. This mutation also characterizes the parental primary cells and was evident in the XPG RNA. Finally, to characterize the XPG DNA repair deficiency in these cell lines, an episomal expression vector containing wild-type XPG cDNA was used to correct UV-induced damage in a beta-galactosidase reporter gene.
Laboratory Medicine and Stromatology, University of California San Francisco, San Francisco, California, 94143, USA.
A R
AR
Ellison
T
T
Nouspikel
N G
NG
Jaspers
S G
SG
Clarkson
D C
DC
Gruenert
D002461:Cell Line, Transformed / Q000378:metabolism* / Q000528:radiation effects; D002472:Cell Transformation, Viral; D003057:Cockayne Syndrome / Q000150:complications / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004720:Endonucleases; D005347:Fibroblasts / Q000378:metabolism* / Q000528:radiation effects; D005838:Genotype; D006801:Humans; D009687:Nuclear Proteins; D010641:Phenotype; D013539:Simian virus 40; D014157:Transcription Factors; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000150:complications / Q000235:genetics*; D000099250:DNA Excision Repair Protein ERCC-5
D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D014157:Transcription Factors; D000099250:DNA Excision Repair Protein ERCC-5