Genetic polymorphism of hOGG1 and risk of pterygium in Chinese

Abstract

Purpose Ultraviolet irradiation is known to cause oxidative DNA damage and is thought to be a major factor implicated in the pathogenesis of pterygium. The highly mutagenic 8-hydroxy-2 0 -deoxyguanosine, a marker for the evaluation of photo-oxidative DNA damage, can be repaired by human 8-oxoguanine glycosylase I (hOGG1). A transition of C to G at nucleotide position 1245 in exon 7 of the hOGG1 gene is associated with the substitution of cysteine for serine at codon 326. In this study, we investigated the association of the hOGG1 Ser326Cys polymorphism with pterygium in a Chinese population. Methods In all, 70 patients and 86 controls were enrolled in this study. The Ser326Cys polymorphism was determined by the polymerase chain reaction-restriction fragment-length polymorphism analysis. The association between this genetic polymorphism and risk of pterygium was examined by w 2 -test and logistic regression. Results The allelic frequencies for the Ser and Cys variants of hOGG1 gene were not significantly different between the two groups. However, when compared with Ser/ Ser and Ser/Cys genotypes combined, we found that the homozygous Cys/Cys genotype was more prevalent in pterygium patients than controls (P ¼ 0.024) with the odds ratio being 2.2 (95% CI: 1.1-4.5). In the pterygium group, the mean age of patients with the Cys/Cys genotype was younger than those with the other two genotypes (P ¼ 0.025). Conclusions Our findings suggest that the 1245C-G transition in exon 7 of the hOGG1 gene, which results in Ser326Cys substitution of the enzyme, might play a role in the susceptibility of humans to pterygium.

Vascular Endothelial Growth Factor Gene 460 Polymorphism Is Associated With Pterygium Formation in Female Patients

“…Polymorphisms in 3 genes (VEGF, glutathione Stransferase M1, and human 8-oxoguanine DNA glycosylase) have been reported elsewhere and here to be associated with pterygium formation. 10,11 There are other genes that may be found to be associated with pterygium formation or its recurrence; therefore, further studies are necessary.…”

“…14,15 Among the reported studies, glutathione S-transferase M1 and human 8-oxoguanine DNA glycosylase 1 polymorphisms were found to be associated with pterygium formation. 10,11 Vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, was highly expressed in pterygium and was suggested to be involved in the fibrovascular proliferation of pterygia. [16][17][18] Because the fibrovascular component is the main part of pterygium and VEGF plays an important role in the component, it is logical to examine the relationship between the VEGF polymorphism and pterygium formation.…”

“…[10][11][12][13] SNPs are the most abundant types of DNA sequence variation in the human genome, and the SNP marker has provided a good method for identification of complex gene-associated diseases and recognition of patients predisposing to the diseases. 14,15 Among the reported studies, glutathione S-transferase M1 and human 8-oxoguanine DNA glycosylase 1 polymorphisms were found to be associated with pterygium formation.…”

Increased oxidative DNA damage, 8-hydroxydeoxy- guanosine, in human pterygium

“…Besides, the patients with Cys/Cys genotype were younger than those with other two genotypes combined (Cys/Ser and Ser/Ser) in the pterygium group. 9 It is suggested that subjects with the Cys326 allele may have more accumulative oxidative damages and thus are more prone to develop pterygium. Our current findings further proved that there was significant higher oxidative DNA damage in pterygium tissue.…”

Role of MDM2 SNP309 gene mutation in pterygium: a pilot study

“…(2) Since pterygium exhibits some characteristics of neoplasia like abnormal cell proliferation, local invasion of adjacent normal tissues and recurrence on excision; recent studies have advocated that pterygium might indeed be a neoplasm like growth disorder occurring in susceptible individuals. (3)(4)(5)(6) The tumor suppressor protein, p53, plays a crucial role in multi-cellular functions, including gene transcription, DNA synthesis and repair, growth arrest, cell senescence, and apoptosis. Mutations of p53 gene that disrupt the balance between cell apoptosis and repair are found in at least half of all human cancers, which highlight its critical role in the tumor suppression.…”