Comparison of L1 gene of human papillomavirus from pterygium and adenocarcinoma cervical tissue

Abstract

Pterygium is a common eye disease and is a fibrovascular lesion of the ocular surface. It is unknown pathogenesis and origin. Environment factors(UV-B light), genetic factors including viral infections may be implicated. Oncogenic virus, HPV has been hypothesized to be related with pterygium progress. Adenocarcinoma is a major histological types of cervical cancer, which emerges within glands and locates in the endocervix. In previous study, HPV 18 and 16 were the most common type found in adenocarcinoma , while HPV 6, 11, 16 and 18 have been previously reported in pterygium. Aim of this study was to determine the prevalence of HPV genotypes and compared the DNA sequence of L1 gene of HPV in pterygium and adenocarcinoma of cervical tissue. In pterygium patients, HPV genotyping by using reverse hybridization was successfully done in 16 of 25 patients (64%). HPV-16 was the most common genotype. Among those 16 samples, 4 samples had mixed infection with HPV-18 (2/25, 8%) and HPV-58 (2/25, 8%). In cervical tissue, the infection of mixed genotypes was the most frequently found (17/23, 73.91%). HPV 51 was found 30.43% (7/23), HPV 58 was 21.74% (5/23), followed by each the HPV16 (4/23, 17.39%) and HPV 53 (4/23, 17.39%) Intragenotypic variations in the L1 regions of each HPV type (HPV-16, 31, 52, 53, 58, 59, 66 and 70) were aligned with reference HPV. Several mutations were identified. The presence of different nucleotide mutations in HPV type 31, 53, 59 and 70 led to amino acid change in the L1 protein. The comparison of L1 gene sequences of HPV type 16 in pterygium and adenocarcinoma cervical tissue showed only 3 different single nucleotide mutations. The results indicate DNA sequence of L1 gene of Human papillomavirus from pterygium and adenocarcinoma cervical tissue were very few different in genomic variant and they were clustered in the same branch of Phylogenetic tree.