Molecular Variants of HPV Type 16 E6 Among Honduran Women

The contribution of Latin American research to HPV epidemiology and natural history knowledge

Our aim was to review the major contributions of studies conducted in different Latin American (LA) countries to the field of human papillomavirus (HPV) epidemiology, natural history, risk of disease, and prevention strategies, mainly in the uterine cervix. Although cytological screening is established in several countries in LA, incidence and mortality rates from cervical cancer (CC) are still extremely high. Finally, data from large cohort studies conducted in LA countries provided seminal data to propose primary and secondary prevention modalities: the HPV vaccine has been introduced in the national immunization programs of several LA countries and multiple screening experiences using HPV testing are under evaluation in the region.

High prevalent human papillomavirus infections of the oral cavity of asymptomatic HIV-positive men

Background

Incidence of anal and oral infections with Human Papillomavirus (HPV) is increasing, particularly among Human Immunodeficiency Virus-positive (HIV+) men. HPV type 16 has exhibited the highest incidence and only limited data is available on other prevalent types, variants of HPV16, as well as associated factors. We were interested in identifying prevalent HPV types, variants of type 16, as well as factors associated with HPV16 infections in the oral cavity of HIV+ men who have sex with men (MSM).

Methods

A cross-sectional study of oral cavity samples from HIV+ MSM, that in a previous study were identified as positive for HPV16 in the anal canal. Cells from the oral cavity (102 samples, paired with 102 from the anal canal of same patient) were used to extract DNA and detect HPV infections using INNO-LiPA HPV Genotyping Extra II, and PCR. From these, 80 samples (paired, 40 anal and 40 oral) were used to identify variants of type 16 by sequencing. Statistical differences were estimated by the X² test, and p values equal to or less than 0.05 were considered significant. SPSS ver. Twenty-four statistical software (IBM Corp) was used.

Results

We found a high prevalence of High-Risk HPV (HR-HPV) and Low-Risk HPV (LR-HPV). Patients were positive in the oral cavity for HR types; 16, 39 and 18 (80.4, 61.8 and 52.9% respectively) and LR types 11 and 6 (53.9 and 34.3% respectively). Surprisingly, only European variants of type 16 were found in the oral cavity, although American Asian (22.5%) and African (2.5%) variants were identified in the anal canal. The analysis showed that CD4 counts could be the most important risk factor associated with HR-HPV infections in the oral cavity, anal canal or both anatomical regions. The risk of infection of the oral cavity with type 18 increased in men diagnosed with HIV for more than 6 years.

Conclusions

Prevalence of both HR and LR HPV’s in the oral cavity of Mexican HIV+ MSM is very high. The fact that only European variants of HPV16 were found in the oral cavity suggest a possible tropism not previously described.

Distribution of HPV 16 E6 gene variants in screening women and its associations with cervical lesions progression

The aim of this study is to investigate distribution of human papillomavirus (HPV) 16 variants in screening healthy women and the potential association between HPV 16 variants and progression of cervical lesions. For this study a total of 2000 healthy women in Tianjin urban area and 212 patients who were HPV 16 positive and underwent colposcopy were analyzed for HPV 16 variants by pyrosequencing. The results show that the HPV 16 was the most prevalent genotype in Tianjin healthy women and five HPV 16 variant types were detected. The HPV 16 variants were determined by sequencing parital E6 region and the detected variants were European prototype E-T350 (E-p), E-G350, E-C109 G, Asian (As) and Asian-American (AA), among which the E-p variant was the most prevalent (82.76%) followed by As variant. Interestingly, in patients with suspected cervical lesions the most prevalent variant was As variant (54.9%) by increasing significance with severity of cervical diseases (OR 4.337; 95% CI 1.248-15.067; P = 0.021), and followed by HPV 16 E-p variant while E-G350 variant only appeared in HSIL and cervical cancer. Our results show that HPV 16 E-p variant was more prevalent than As in Tianjin healthy screening women while As variant was the most frequently type in HSIL and cervical cancer. It is suggested that the mutation of HPV 16 Asian variants, comparing with HPV 16 E-p variants, might contribute to the transformation from HPV 16 persistent infection to cervical cancer.

Human papillomavirus (HPV) genotypes and HPV16 variants and risk of adenocarcinoma and squamous cell carcinoma of the cervix

OBJECTIVE

Human papillomavirus (HPV) genotypes have been extensively studied in uterine cervix squamous cell carcinoma and HPV16 variants have been found to be associated with increased cancer risk, but few reports have been published on genotype distribution and HPV16 variant prevalence in adenocarcinoma tumors. The objective of this study was to analyze viral genotypes and HPV16 intratypic variants in cervical adenocarcinoma and squamous cell carcinoma of Italian women.

METHODS

A total of 39 invasive adenocarcinoma and 132 squamous cell carcinoma were reviewed and classified according to the modified WHO classification. HPV sequences were detected by nested PCR, using the broad spectrum consensus-primer pairs MY09/MY11 and the GP5+/GP6+ system, and genotyped by nucleotide sequence analysis. The HPV16-positive cases were amplified with E6-specific oligonucleotides and amplimers subjected to direct nucleotide sequence for variant identification.

RESULTS

The prevalence rate of any HPV infection was 72% in adenocarcinoma, and 85% in cervical squamous cell carcinoma. Among the 140 HPV-positive cancer cases, a total of nine mucosal HPV genotypes (HPV16, 18, 31, 33, 35, 39, 45, 58, 82) epidemiologically classified as carcinogenic or probably carcinogenic viruses were identified. The HPV type 16 was the most common viral type representing 64% and 73% of all infections in adenocarcinoma and squamous cell carcinoma, respectively. The E6 nucleotide sequence analysis of HPV16 isolates allowed the identification of Asian American (AA) variants in 33% of adenocarcinoma and in 20% of squamous cell carcinoma suggesting their stronger association with cancer of glandular origin.

CONCLUSION

These results suggest that HPV16 has a high prevalence in both invasive adenocarcinoma and squamous cell carcinoma from Italian patients. Moreover this study confirms previous observations, summarized in a systematic review of the literature, on the increased cancer risk of HPV16 AA class in adenoglandular cancer, possibly related to their more oncogenic behavior compared to HPV16 European variants.

Human papillomavirus type 16 e6 gene variations in young Chinese women with cervical squamous cell carcinoma

Human papillomavirus (HPV) 16 E6 gene mutation is considered an important genetic change in cervical lesion progression. To explore the possible association of specific HPV16 E6 sequence variations with the development of invasive cervical squamous cell carcinoma (SCC) in young women, we examined the distribution of HPV16 E6 variants in a Chinese cervical SCC population and analyzed the difference between younger patients (≤35 years, n = 50) and older ones (>35ys, n = 71). Human papillomavirus type 16 E6 DNA was amplified by polymerase chain reaction and sequenced by Sanger fluorescent dye dideoxy-termination method. Analysis revealed that the most frequently found variation in this Chinese population was the EV (As) lineage (65.45%). In addition, the EV (As) lineage seems more common and uniform in younger patients than other lineages, and it may be associated with early age at diagnosis of cervical SCC in young women.