Human papillomavirus genital infection in modern gynecology: genetic and genomic aspects

Comparative study of HPV16 integration in cervical lesions between ethnicities with high and low rates of infection with high-risk HPV and the correlation between integration rate and cervical neoplasia

The etiology of a high incidence of cervical cancer in populations with a low human papillomavirus (HPV) infection rate is unclear. The current study aimed to investigate the role of HPV16 DNA integration in cervical lesions in women of Han and Uygur ethnicity and to explore the association between viral integration and a high cervical cancer morbidity with a low HPV infection rate. DNA was extracted from the biopsy specimens of cervical lesions of 379 patients of Uygur ethnicity and 464 patients of Han ethnicity, and multiple quantitative polymerase chain reaction (qPCR) assays were performed to determine the copy numbers of the HPV16 E2 and E6 genes. The copy number of the HPV16 DNA was evaluated according to the E2/E6 ratio. Among these cases, 122 Uygur and 121 Han specimens were found to be HPV16 positive. In the two populations, the percentage of cases with HPV16 integration (the sum of integrated-type infection only or a mixture of free-and integrated-type infection) increased with the grade of the cervical lesions (P<0.001). Within groups with the same cervical lesion grade, no significant differences in HPV16 integration were found between women of Uygur and Han ethnicity (rank sum test, P>0.05). No significant differences in the distribution of the HPV16 integration rate according to lesion grade were found in either population (P>0.05). When the two subpopulations were considered as one sample population, the integration rate significantly increased with lesion grade (P=0.02). These results indicate that the integration rate of HPV16 E2 may serve as a molecular biological marker for the development of cervical lesions.

State of HPV16 integration in Lithuanian women with cervical neoplasia

Cervical cancer morbidity and mortality in Lithuania is one of the biggest in the European Union. The main risk factor of cervical cancer is human papillomavirus (HPV). The deletion of the HPV E2 gene influences HPV DNA integration into the cell genome, as well as a rapid progression of cervical lesions. The purpose of this study is to determine HPV, its types, and HPV 16 integration in different grades of cervical intraepithelial neoplasias (CIN). 253 women with cytological lesions were involved in the study. After a histology, 31 women were diagnosed with CIN I, 35 with CIN II, and 51 with CIN III. The biggest prevalence of HPV infection was detected in women younger than 25 years old (69.7%) and in women with CIN II (90.9%). HPV 16 was detected in 67.8% of all cases, with the highest prevalence in CIN III (84.4%). A partial integration form was detected in 65.0% of HPV 16 infected women, a complete virus integration in 26.5%, and an episomal form in 8.4% of cases. Our study concludes that in all the cases confirmed using a histology, the partial virus integration form of CIN was identified the most. It was less frequently detected in CIN I cases (60.0%), but more frequently in CIN II and CIN III cases (72.8 and 69.3%, respectively).

Molecular methods for a correct diagnosis of multiple HPV infections and clinical implications for vaccine

INTRODUCTION

The human papillomavirus (HPV) family is characterized by minimal genotypic differences corresponding to different virus types. The aim of this study was to detect the HPV coinfections and the inner genotype in a series of 336 cervical-vaginal samples.

METHODS

A total of 336 cervical-vaginal samples were taken from 2007 to 2009 using specific molecular techniques such as molecular sequencing and hybridizations. The genome amplification of the L1 open reading frame was analyzed by real-time polymerase chain reaction; direct sequencing was performed by SYBR green fluorescent molecule and degenerate primers MY09 and MY11. The HPV genotyping was accomplished via oligonucleotide probe hybridization. The phylogenetic correlations in coinfections were analyzed by sequence homology of the L1 genomic region. Identified genotypes were then compared.

RESULTS

Human papillomavirus positivity was observed in 125 cases (37.2%), with 21 cases (16.8%) of HPV presence in coinfections. Coinfections involved HPV 16 genotype (8 cases) and HPV 18 (5 cases). The HPV 16 infection was mainly associated with genotypes with a lower-than-broad sequence homology, so the HPV 18 was linked to genotypes represented in the opposite phylogenetic tree.

CONCLUSIONS

The combined and steady use of diagnostic procedures, such as real-time polymerase chain reaction, molecular hybridization, direct sequencing, and HPV genotyping test, allow accurate diagnosis of monoinfections and coinfections. This may faciliate the development of specific viral tests and prophylactic anti-HPV vaccines.