The human DNA excision repair gene, ERCC2 (XPD), substantially corrected the plasmid UV hypersensitivity and UV hypermutability of xeroderma pigmentosum complementation group D cells; however, the dose response relationship varied for different end points.
These cellular phenotypes are amenable to experimental strategies employing complementation, an approach previously used to demonstrate the correction of XP-D phenotypes following the introduction of the XPD (ERCC2) gene.
Various combinations of the keywords and MeSH terms were used to screen for potentially relevant studies, specifically "genetic polymorphisms" or "SNPs" or "variation" or "single nucleotide polymorphism" or "polymorphism" or "mutation" or "variant"; "X-ray repair cross complementing protein 1" or "Xeroderma Pigmentosum Group D Protein" or "X-ray repair cross complementing protein 1" or "Xeroderma Pigmentosum Group D Protein" or "XPD" or "Xeroderma Pigmentosum Complementation Group D Protein" or "ERCC2" or "XRCC1" or "XRCC1 DNA repair protein"; and "Cataract" or " Membranous Cataract" or " Pseudoaphakia."
DNA repair gene polymorphisms, such as those of XRCC3 and xeroderma pigmentosum, complementation group D and G (XPD, XPG), contribute to carcinogenesis.
We assessed polymorphisms in the aryl hydrocarbon receptor (AhR-Arg554Lys), null variants of the glutathione S-transferase superfamily (GSTM1 and GSTT1), x-ray repair cross-complementing 1 and 3, and Xeroderma pigmentosum, group D (XRCC1-Arg399Gln, XRCC3-Thr241Met, XPD-Lys751Gln).
While HD1A closely resembles the XPD phenotype in terms of u.v. sensitivity and excision repair it differs from XPD because of its ability to reactivate u.v.-irradiated adenovirus 2 to an extent similar to that of its HeLa parent.
Nucleotide sequence analysis of the ERCC2 cDNA from five XP group D cell strains [XP6BE(SV40), XP17PV, XP102LO, A31-27 (a HeLa/XP102LO hybrid), and XP-CS-2] revealed mutations predominantly affecting previously identified functional domains.
XPD (ERCC2) is a DNA helicase involved in nucleotide excision repair and in transcription as a structural bridge tying the transcription factor IIH (TFIIH) core with the cdk-activating kinase complex, which phosphorylates nuclear receptors.
For the most part, the authors found no association between these genes and the cancer sites investigated, except for some statistically significant associations between XPD/ERCC2 single nucleotide polymorphisms and skin, breast, and lung cancers.
These results establish the essential function of the XPD protein in mammals and in cellular viability and are consistent with the notion that only subtle XPD mutations are found in XP, XP/Cockayne syndrome, and trichothiodystrophy patients.
To characterize nucleotide excision repair properties of cells from trichothiodystrophy (TTD) patients genetically-related to the xeroderma pigmentosum (XP) group D, TTD skin fibroblasts from two unrelated patients (TTD1VI and TTD2VI) belonging to the TTD/XPD group were transformed with a plasmid containing SV40 large T antigen-coding sequences and some DNA repair properties, such as unscheduled DNA synthesis (UDS), UV-survival, in vitro repair synthesis of cell extracts and reactivation of UV-irradiated reporter plasmid were studied.
No major modifications of the ERCC-2 gene were detected with two cDNA probes in either XP-D or TTD patients indicating that the association between TTD and XP-D is not likely to result from a large deletion or rearrangement involving this gene.
The Xeroderma pigmentosum group D (XPD, also referred to as excision repair cross complementing gene 2, ERCC2) is one of key genes involved in nucleotide excision repair and two potentially functional polymorphisms of XPD (Asp312Asn and Lys751Gln) have been widely investigated in various cancers including prostate cancer.
Genome sequence analysis indicated that the patient harbored a compound heterozygous mutation of c.1621A>C and c.591_594del, resulting in p.S541R and p.Y197* in ERCC2: then, patient was diagnosed with XP-D. Y197* has not been described before.
Thus, we are developing a model for gene therapy in XP, particularly for patients belonging to group D. We report here the construction of a retroviral vector (LXPDSN) containing the XPD (ERCC2) cDNA, which fully complements the DNA repair deficiency of primary skin fibroblasts.
In most cases, xeroderma pigmentosum group D (XP-D) and trichothiodystrophy (TTD) patients carry mutations in the carboxy-terminal domain of the evolutionarily conserved helicase XPD, which is one of the subunits of the transcription/repair factor TFIIH (refs 1,2).
To study the relationships between mutagenesis and carcinogenesis, we compared the mutations and their frequency induced by ultraviolet irradiation at 254 nm (UV-C) in XP-D (GM-08207B/XP6BE), TTD/XP-D (TTD1VI-LAS-KMT11) and wild-type (MRC-5V1) human cells.
When the genotype frequencies of XPD (Llys751Gln) and XRCC1 (Arg399Gln) genes were examined in the patient and control groups, no significant difference was detected, while a significant association was found in XRCC4 (VNTR in intron 3 and G-1394T) polymorphisms.