HPV16 genetic variation and the development of cervical cancer worldwide

Association of Human Papillomavirus Genotype 16 Viral Variant and Viral Load with Cervical High-grade Intraepithelial Lesions

Human papillomavirus genotype 16 (HPV16) is by far the genotype most strongly associated with cervical cancer; viral variant and/or viral load of HPV16 could modulate this association. The objective was to determine the association between the viral variant and viral load of HPV16 and the presence of cervical high-grade lesions. This cross-sectional study included all women in whom HPV infection was found by cervical smear during routine gynecologic health checks. Women with single or multiple HPV16 infections (n = 176) were selected for viral variant and viral load analysis. Smear results were classified using the Bethesda system. HPV types were classified according to the International Agency for Research on Cancer. Odds ratios (OR) with their 95% confidence intervals (CI) were estimated by logistic regression, adjusted for age, immigrant status, and coinfection with other high-risk genotypes. No statistically significant associations were found regarding the detected viral variants. A viral load above the median (>1,367.79 copies/cell) was associated with a significant risk of high-grade epithelial lesion or carcinoma, after adjusting for age, immigrant status, coinfections, and viral variant: (adjusted OR 7.89; 95% CI: 2.75-22.68). This relationship showed a statistically significant dose-response pattern after categorizing by viral load tertiles: adjusted OR for a viral load greater than the third tertile was 17.23 (95% CI: 4.20-70.65), with adjusted linear P _trend = 0.001. In patients infected with HPV16, viral load is associated with high-grade intraepithelial lesions or cervical carcinoma. This could be useful as prognostic biomarker of neoplastic progression and as screening for cervical cancer.

Human papillomavirus 16 sub-lineage dispersal and cervical cancer risk worldwide: Whole viral genome sequences from 7116 HPV16-positive women

BACKGROUND

Human papillomavirus (HPV)16 can be separated into genetic sub-lineages (A1-4, B1-4, C1-4, D1-4) which may have differential cervical cancer risk.

METHODS

A next-generation sequencing assay was used to whole-genome sequence 7116 HPV16-positive cervical samples from well-characterised international epidemiological studies, including 2076 controls, 1878 squamous cell carcinoma (SCC) and 186 adenocarcinoma/adenosquamous cell carcinoma (ADC), and to assign HPV16 sub-lineage. Logistic regression was used to estimate region-stratified country-adjusted odds ratios (OR) and 95%CI.

RESULTS

A1 was the most globally widespread sub-lineage, with others showing stronger regional specificity (A3 and A4 for East Asia, B1-4 and C1-4 for Africa, D2 for the Americas, B4, C4 and D4 for North Africa). Increased cancer risks versus A1 were seen for A3, A4 and D (sub)lineages in regions where they were common: A3 in East Asia (OR=2.2, 95%CI:1.0-4.7); A4 in East Asia (6.6, 3.1-14.1) and North America (3.8, 1.7-8.3); and D in North (6.2, 4.1-9.3) and South/Central America (2.2, 0.8-5.7), where D lineages were also more frequent in ADC than SCC (3.2, 1.5-6.5; 12.1, 5.7-25.6, respectively).

CONCLUSIONS

HPV16 genetic variation can strongly influence cervical cancer risk. However, burden of cervical cancer attributable to different sub-lineages worldwide is largely driven by historical HPV16 sub-lineage dispersal.

Mucosal and Cutaneous Human Papillomavirus Infections and Cancer Biology

Papillomaviridae is a family of small non-enveloped icosahedral viruses with double-stranded circular DNA. More than 200 different human papillomaviruses (HPVs) have been listed so far. Based on epidemiological data, a subgroup of alphapapillomaviruses (alpha HPVs) was referred to as high-risk (HR) HPV types. HR HPVs are the etiological agents of anogenital cancer and a subset of head and neck cancers. The cutaneous HPV types, mainly from beta and gamma genera, are widely present on the surface of the skin in the general population. However, there is growing evidence of an etiological role of betapapillomaviruses (beta HPVs) in non-melanoma skin cancer (NMSC), together with ultraviolet (UV) radiation. Studies performed on mucosal HR HPV types, such as 16 and 18, showed that both oncoproteins E6 and E7 play a key role in cervical cancer by altering pathways involved in the host immune response to establish a persistent infection and by promoting cellular transformation. Continuous expression of E6 and E7 of mucosal HR HPV types is essential to initiate and to maintain the cellular transformation process, whereas expression of E6 and E7 of cutaneous HPV types is not required for the maintenance of the skin cancer phenotype. Beta HPV types appear to play a role in the initiation of skin carcinogenesis, by exacerbating the accumulation of UV radiation-induced DNA breaks and somatic mutations (the hit-and-run mechanism), and they would therefore act as facilitators rather than direct actors in NMSC. In this review, the natural history of HPV infection and the transforming properties of various HPV genera will be described, with a particular focus on describing the state of knowledge about the role of cutaneous HPV types in NMSC.

Whole-Genome Analysis of Human Papillomavirus Type 16 Prevalent in Japanese Women with or without Cervical Lesions

Recent large-scale genomics studies of human papillomaviruses (HPVs) have shown a high level of genomic variability of HPV16, the most prevalent genotype in HPV-associated malignancies, and provided new insights into the biological and clinical relevance of its genetic variations in cervical cancer development. Here, we performed deep sequencing analyses of the viral genome to explore genetic variations of HPV16 that are prevalent in Japan. A total of 100 complete genome sequences of HPV16 were determined from cervical specimens collected from Japanese women with cervical intraepithelial neoplasia and invasive cervical cancer, or without cervical malignancies. Phylogenetic analyses revealed the variant distribution in the Japanese HPV16 isolates; overall, lineage A was the most prevalent (94.0%), in which sublineage A4 was dominant (52.0%), followed by sublineage A1 (21.0%). The relative risk of sublineage A4 for cervical cancer development was significantly higher compared to sublineages A1/A2/A3 (odds ratio = 6.72, 95% confidence interval = 1.78–28.9). Interestingly, a novel cluster of variants that branched from A1/A2/A3 was observed for the Japanese HPV16 isolates, indicating that unique HPV16 variants are prevalent among Japanese women.

Human papillomavirus type 16 E6 and E7 gene variations associated with cervical cancer in a Han Chinese population

BACKGROUD

Human papillomavirus type 16 (HPV16) is a high-risk HPV subtype and a potent carcinogen. The HPV16 E6 and E7 genes are considered oncogenes that play a core role in the development of cervical cancer.

METHODS

In the current study, we enrolled 97 HPV16-positive cervical cancer patients (case group) and 136 HPV16-positive asymptomatic individuals (control group) in a study to analyse the association between HPV16 E6 and E7 gene variations and cervical cancer.

RESULTS

Our results showed that three HPV16 sub-lineages (A1-A3, A4 and D3) were present; the distribution of these variants between the case and control group was not significantly different (P = 0.178). When the distribution of the HPV16 E6 and E7 gene variations was compared, the distribution of only A131C (R10R) in the E6 gene showed a different trend between the case and control groups and C749T (S63F) in the E7 gene was significantly different between the case and control groups (P = 0.071 and P = 4.861 × 10^-10, respectively). Regarding the sub-lineages, no variations in the E6 gene were significantly different between the case and control group for the A4 (As) and A1-A3 (EUR) sub-lineages. However, the distribution of C749T (S63F) in the E7 gene was significantly different between the case and control groups for the A4 (As) and A1-A3 (EUR) sub-lineages (P = 1.815 × 10^-8 and P = 0.008). In the current study, we found that the C749T (S63F) variation in the HPV16 E7 gene was associated with cervical cancer not only in the A4 (As) sub-lineage but also in the A1-A3 (EUR) sub-lineage.

CONCLUSION

Our study will provide a good reference for further functional studies of the relationship between cervical cancer carcinogenesis and the HPV16 E6 and E7 genes.

Genetic variations in E6, E7 and the long control region of human papillomavirus type 16 among patients with cervical lesions in Xinjiang, China

Background

Xinjiang is one of the areas with the highest incidence of cervical cancer in China. Genetic variation in Human papillomavirus type 16 (HPV16) may increase the ability of the virus to mediate carcinogenesis and immune escape, which are risk factors for the progression of cervical cancer. We investigated polymorphism in HPV16 and the distribution of its sub-lineages in the region by analyzing the E6, E7 and long control region (LCR) gene sequences from women with HPV16-positive cervical samples in Xinjiang.

Methods

A total of 138 cases of cervical lesions and squamous cell carcinoma with infection of HPV16 virus were collected. The E6 and E7 genes and LCR of HPV16 virus were sequenced and compared with the HPV16 European prototype reference and other HPV16 mutants for single nucleotide polymorphisms. Neighbor-joining phylogenetic trees were constructed using E6, E7 and LCR sequences.

Results

Fourteen missense mutations were found in the E6 gene; the loci with the highest mutation frequency were T350G (36/75, 48%) and T178G (19/75, 25.3%). In the E7 gene, the locus with the highest mutation frequency was A647G (18/75, 24%). A total of 33 polymorphic sites were found in the LCR, of which T7447C (39/95, 40.1%) was the most frequent.

Conclusion

HPV16 in Xinjiang is mainly of the European variant, followed by the Asian variant type; no Africa 1, 2 or Asia–America variant types were found.

TaME-seq: An efficient sequencing approach for characterisation of HPV genomic variability and chromosomal integration

HPV genomic variability and chromosomal integration are important in the HPV-induced carcinogenic process. To uncover these genomic events in an HPV infection, we have developed an innovative and cost-effective sequencing approach named TaME-seq (tagmentation-assisted multiplex PCR enrichment sequencing). TaME-seq combines tagmentation and multiplex PCR enrichment for simultaneous analysis of HPV variation and chromosomal integration, and it can also be adapted to other viruses. For method validation, cell lines (n = 4), plasmids (n = 3), and HPV16, 18, 31, 33 and 45 positive clinical samples (n = 21) were analysed. Our results showed deep HPV genome-wide sequencing coverage. Chromosomal integration breakpoints and large deletions were identified in HPV positive cell lines and in one clinical sample. HPV genomic variability was observed in all samples allowing identification of low frequency variants. In contrast to other approaches, TaME-seq proved to be highly efficient in HPV target enrichment, leading to reduced sequencing costs. Comprehensive studies on HPV intra-host variability generated during a persistent infection will improve our understanding of viral carcinogenesis. Efficient identification of both HPV variability and integration sites will be important for the study of HPV evolution and adaptability and may be an important tool for use in cervical cancer diagnostics.

Variant sublineages of human papillomavirus type 16 predispose women to persistent infection characterized by a sequence analysis of the E6, L1, and LCR regions

BACKGROUND

One of the precursors of cervical cancer is persistent infection with human papillomavirus (HPV), especially high-risk HPV. The aim of this study was to verify the relationship between HPV16 variants and persistent viral infection.

METHODS

Three-hundred and eighty-six Chinese women who had a low-grade squamous intraepithelial lesion (LSIL) or a lesion below LSIL with normal cellular morphology were selected and enrolled in this study. Flow-through hybridization and gene chip technology were applied to identify the HPV type, and a PCR-sequencing assay was performed to detect HPV16 E6, L1, and long control region (LCR) gene variants. The relationship between HPV16 variants and persistent infection was analyzed using Fisher's exact test.

RESULTS

In this population, 74.09% of HPV16 isolates belonged to the A4 sublineage, 24.87% to the A1/A2 sublineages, and 3.13% to B1/B2 sublineages. In addition, the A4 sublineage T178G (P<0.001) and the A1/A2 sublineages T350G and A442C (P<0.001) were associated with persistent HPV16 infection. L1 and LCR variants were found to be common in this population. Nonetheless, no significant relation was identified between the L1 or LCR variants and the persistence of infection (P>0.05).

CONCLUSION

HPV16 E6 variants in the Shanghai Pudong District mainly belong to the A4 sublineage, and detection of the specific HPV E6 T178G genotype may be considered a risk factor for viral persistence and progression to other cervical diseases.

Human Papillomavirus Type 16 E1 Mutations Associated with Cervical Cancer in a Han Chinese Population

Human papillomavirus type 16 (HPV16) is a high-risk HPV type and a potent carcinogen. HPV E1 is one of the most highly conserved proteins and it plays a central role in initiating HPV DNA replication. In current study, we enrolled 161 HPV16-positive cervical cancer patients (case group) and 171 HPV16-positive asymptomatic individuals (control group) in a study to analyse the association between HPV16 E1 genetic mutations and cervical cancer. The samples of case group were cervical cancer tissues and the samples of control group were cervical exfoliated cells. Three variants (A4, A1-A3 and D3) were found in the case group, 68.3% of the HPV16 E1 sequences belonged to the A4 (As) sub-lineage, 29.2% belonged to the A1-A3 (EUR) sub-lineage, and 2.5% belonged to the D3 (AA1) sub-lineage. Two variants (A4 and A1-A3) occurred in the control group. The A4 (As) sub-lineage was predominant in this group as well (66.1%), followed by the A1-A3 (EUR) sub-lineage (33.9%), but the D3 (AA1) sub-lineage was not found in the control group. The distribution of the HPV16 variants between the case and control groups was significantly different (P<0.05). When the distribution of the HPV16 E1 gene mutations was compared, the distribution of twenty-seven mutations was significantly different between the case and control groups (P<0.05), and twenty-two mutations occurred only in the D3 (AA1) sub-lineage, two were found only in the A4 (As) sub-lineage, one was found in the A1-A3 (EUR) sub-lineage, two was found in both the A4 (As) and A1-A3 (EUR) sub-lineages. In the sub-lineage analysis, the differences in the T933A (A23A), T1014G (D50E) and G2160A (R432R) mutations were statistically significant between the case and control groups for the A4 (As) sub-lineage (P<0.05), and the differences in the T2232C (F456F), G2337A (M491I) and A2547G (P561P) mutations were statistically significant between the case and control groups for the A1-A3 (EUR) sub-lineage (P<0.05). In the current study, we describe specific mutations in the HPV16 E1 gene associated with cervical cancer, and our study will provide a good reference for further functional studies of the relationship between cervical cancer carcinogenesis and HPV genes.

Phylogeny and Classification of Human Papillomavirus (HPV)16 and HPV18 Variants Based on E6 and L1 genes in Tunisian Women with Cervical Lesions

Background:

High-risk human papillomavirus (HPV) types are the main etiological factors for cervical cancer. HPV16 and HPV18 are generally the most common forms associated with development of high-grade cervical lesions. This study was undertaken to identify intratypic variants of HPV16 and HPV18 among women with cervical lesions in Tunisia.

Materials and Methods:

DNA was extracted from cervical samples collected from 49 women. using a PureLinkTM Genomic DNA mini Kit (Invitrogen). E6 and L1 open reading frames (ORF) were amplified by PCR and viral DNA amplicons were subjected to automated sequencing using Big Dye Terminators technology (Applied Biosystems). The obtained sequences were analyzed using an appropriate software program to allow phylogenetic trees to be generated.

Results:

HPV16 and HPV18 were detected in 15 and 5 cases, respectively. HPV16 E6 sequences clustered with the European German lineage (A2) whereas one isolate diverged differently in the L1 region and clustered with the African sub-lineage (B1). HPV 18 E6 sequences clustered with the European sub-lineage (A1) but L1 sequences clustered as a new clade which diverged from A1-A5.

Conclusions:

Our results suggest that the distribution of HPV16 and HPV18 sequences in women with cervical lesions in Tunisia is mainly related to European epidemiological conditions and point to the presence of recombinant HPV forms.

Concurrent HPV-related oropharyngeal carcinoma in four couples

OBJECTIVES

Typically, HPV-related cancers are sexually transmitted, however, the natural history of HPV-related oropharyngeal squamous cell carcinoma (OPSCC) is unclear. HPV16 transmission has been reported previously between five couples with OPSCC. We report the clinico-pathological features of a further four couples with HPV-related OPSCC and compare them with the published cases.

PATIENTS AND METHODS

We identified four couples in long-term heterosexual relationships that all had HPV-related OPSCC. The couples were treated at three UK hospitals and presented between 2009 and 2015. HPV tests included p16 immunohistochemistry, high-risk HPV DNA in-situ hybridisation and Roche Cobas HPV test. DNA sequencing was used to determine the HPV variant.

RESULTS

The four couples represented < 2% of patients with HPV-related OPSCC at the three contributing hospitals (8 of 457 consecutive patients). The couples' tumours all contained HPV16. The mean age was 63 years old (range 52-72 years). The interval between the index cancer and the partner's cancer was 16, 24, 26 and 64 months respectively. The majority of patients had Stage I disease (UICC TNM8). Six of eight patients are disease free, one patient is alive with disease and there was one death from loco-regional recurrence.

CONCLUSION

This report highlights the occurrence of HPV-related OPSCC in heterosexual couples and raises the possibility of transmission of HPV16. Despite increasing prevalence of HPV-related OPSCC and increased awareness of the disease, there is a paucity of couples with the disease, suggesting either under-reporting or that the development of OPSCC following HPV transmission between couples is a rare event.

Eurogin roadmap 2017: Triage strategies for the management of HPV-positive women in cervical screening programs

Cervical cancer screening will rely, increasingly, on HPV testing as a primary screen. The requirement for triage tests which can delineate clinically significant infection is thus prescient. In this EUROGIN 2017 roadmap, justification behind the most evidenced triages is outlined, as are challenges for implementation. Cytology is the triage with the most follow-up data; the existence of an HR-HPV-positive, cytology-negative group presents a challenge and retesting intervals for this group (and choice of retest) require careful consideration. Furthermore, cytology relies on subjective skills and while adjunctive dual-staining with p16/Ki67 can mitigate inter-operator/-site disparities, clinician-taken samples are required. Comparatively, genotyping and methylation markers are objective and are applicable to self-taken samples, offering logistical advantages including in low and middle income settings. However, genotyping may have diminishing returns in immunised populations and type(s) included must balance absolute risk for disease to avoid low specificity. While viral and cellular methylation markers show promise, more prospective data are needed in addition to refinements in automation. Looking forward, systems that detect multiple targets concurrently such as next generation sequencing platforms will inform the development of triage tools. Additionally, multistep triage strategies may be beneficial provided they do not create complex, unmanageable pathways. Inevitably, the balance of risk to cost(s) will be key in decision making, although defining an acceptable risk will likely differ between settings. Finally, given the significant changes to cervical screening and the variety of triage strategies, appropriate education of both health care providers and the public is essential.

Human papillomavirus genome variants and head and neck cancers: a perspective

Human papillomaviruses (HPV) cause infections that are responsible for diverse clinical manifestations from benign conditions to invasive cancer. As different HPV types are associated with variable pathogenic potential, minor genetic variations within a given high-risk HPV type might also be associated with distinct oncogenic capacities, through variable ability of persistence or risk of progression to precancer/cancer. Most recent HPV variant studies in the cervix using latest sequencing technology confirmed that minor changes in the HPV genome can have a major influence on carcinogenesis and have revealed key data that help better understand the carcinogenicity of HPV at a molecular level. Here we review the limited number of studies on HPV genome variants in head and neck cancers (HNC) and discuss their implications for cancer research in the light of accumulated knowledge for the cervix. Challenges in transposing HPV variant studies from the lower anogenital to the upper aerodigestive tract are also discussed, highlighting the main gaps of knowledge in the field of HPV-induced HNC. Specifically in the head and neck region, the lack of characterisation of precancerous lesions and the difficulty in sampling normal tissue will challenge the development of accurate studies. Although there is so far no indication that HPV variant research in HNC could directly translate into clinical application, such research is expected to be useful to disentangle unanswered questions in the pathogenesis of HNC. Yet, history of HPV variant research suggests that, to be successful, studies will require large international collaborative efforts.

The correlation between TNF-α-308 gene polymorphism and susceptibility to cervical cancer

Tumor necrosis factor-α (TNF-α) is closely related to the occurrence of human cancers. Cervical cancer seriously affects female health. Therefore, our study aimed to investigate the correlation between the polymorphism of TNF-α-308 gene and susceptibility to cervical cancer. Whole blood was collected from 142 patients with cervical cancer and 150 healthy controls. PCR-RFLP was used to detect the polymorphism of TNF-α-308 and the correlation between polymorphism of TNF-α-308 and the susceptibility to cervical cancer was analyzed. The three genotypes of TNF-α-308 were GG, GA and AA, and the distributions of genotypes of TNF-α-308 were consistent with Hardy-Weinberg equilibrium in both cervical cancer group and control group. There were no significant differences in genotype and allele frequency between cervical cancer group and healthy control group (P>0.05). A/A genotype increased the risk of cervical cancer by 1.46 times with 95% confidence interval of 0.32-6.67. Different genotypes were not associated with tumor type (P>0.05). Different genotypes are correlated with cervical cancer TNM stages, tumor differentiation and lymph node metastasis. Proportion of GA+AA genotype in TNM stage III+IV group, low differentiation group and lymph node metastasis group were 28.1, 29.0 and 29.8%, respectively, which were significantly higher than those in stage I+II group, moderate/high differentiation group and non-lymph node metastasis group (P<0.05). The results suggested that TNF-α-308 gene polymorphism is associated with the degree of malignancy of cervical cancer. Female patients with A allele have higher malignant degree of cervical cancer.

The Intersection of HPV Epidemiology, Genomics and Mechanistic Studies of HPV-Mediated Carcinogenesis

Of the ~60 human papillomavirus (HPV) genotypes that infect the cervicovaginal epithelium, only 12–13 “high-risk” types are well-established as causing cervical cancer, with HPV16 accounting for over half of all cases worldwide. While HPV16 is the most important carcinogenic type, variants of HPV16 can differ in their carcinogenicity by 10-fold or more in epidemiologic studies. Strong genotype-phenotype associations embedded in the small 8-kb HPV16 genome motivate molecular studies to understand the underlying molecular mechanisms. Understanding the mechanisms of HPV genomic findings is complicated by the linkage of HPV genome variants. A panel of experts in various disciplines gathered on 21 November 2016 to discuss the interdisciplinary science of HPV oncogenesis. Here, we summarize the discussion of the complexity of the viral–host interaction and highlight important next steps for selected applied basic laboratory studies guided by epidemiological genomic findings.

Association of codon 72 polymorphism of p53 with the severity of cervical dysplasia, E6-T350G and HPV16 variant lineages in HPV16-infected women

Purpose. Polymorphic variability in the tumour-suppressor protein p53 at codon 72 has a considerable impact on cervical cancer development. The present study clarified the association between p53 codon 72 genotypes and the risk of cervical disease in Greek patients. We also examined whether the presence of specific p53 genotypes in combination with HPV16 variants or E6 T350G sequence variation can modify an individual's susceptibility to cervical disease.Methodology. The analysis of p53 genotypes was performed through PCR-RFLP. Sequence and phylogenetic tree analyses of the HPV16 E6 gene were also performed in order to identify HPV16 variants and T350G sequence variation.Results/Key findings. The outcomes of the present analysis revealed that women who are homozygous for the arg genotype are at a 4.17-fold higher risk of developing HPV16-associated HSIL+ (OR=4.17, 95 % CI:1.48-4.9, P=0.0049). Moreover, p53 arg/arg patients infected by an HPV16 prototype strain were associated with an increased risk of more severe lesions, while a significant relationship between the p53 arg/arg genotype in patients with T350G sequence variation and the risk of high-grade squamous intraepithelial lesions (HSILs) was revealed.Conclusion. The oncogenic potential of the virus is increased by the presence of the p53 arg/arg genotype in the Greek population in such a way that the specific protein interaction E6 (L83V)-p53 (Arg-72) can modify an individual's susceptibility to cervical disease.

Human papillomavirus type 16 lineage analysis based on E6 region in cervical samples of Iranian women

It is suggested that distinct HPV 16 variants differ in oncogenic potential and geographic distribution. As such, understanding the regional variants of HPV 16 would be of great importance for evolutionary, epidemiological and biological analysis. In this regard, the sequence variations of E6 gene were investigated to characterize more common variants of HPV 16 in normal cells, premalignant and malignant lesions of the cervix. In total, 106 isolates of HPV 16 were analyzed by PCR and sequencing. Overall, two different lineages (A and D) were identified. Lineage D comprised 70.7% of samples and the remaining 29.3% belonged to lineage A. Regarding to cytology/histology, lineage D was dominant in both normal+CIN I-II and CIN III+ICC groups as it was detected in 80% and 66.2% of cases, respectively. The comparison of the lineages between different groups (35 normal+CIN I-II samples and 71 CIN III+ICC samples) revealed that lineage A is more prevalent in cervical cancer cases (7 (20%) vs. 24 (33.8%)) although the difference observed did not reach statistical significance (p=0.07). In conclusion, our findings confirm that HPV lineages A and D are more prevalent in Iran, with the lineage D as the most dominant in all studied groups.

Human papillomavirus type distribution and HPV16 intratype diversity in southern Brazil in women with and without cervical lesions

BACKGROUND

Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer.

OBJECTIVES

This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions.

METHODS

HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified.

FINDINGS

A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B.

MAIN CONCLUSIONS

This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.

Genetic diversity of human papillomavirus types 35, 45 and 58 in cervical cancer in Brazil

In Brazil, most studies of intra-type variants of human papillomavirus (HPV) have focused on HPV16 and HPV18, but other high-risk HPV types have not been studied. Here, we report the prevalence of lineages and variants of HPV35, HPV45 and HPV58 in cervical cancers from the Amazonian and Southeast Brazilian regions. The most frequent sublineages were A1 for HPV35, B2 for HPV45, and A2 for HPV58. The Southeast region had a higher frequency of the B2 sublineage of HPV45, and for HPV35, the genetic and nucleotide sequence diversity were higher in the Southeast region, suggesting that regional factors are influencing the diversity and lineage prevalence.

The high prevalence of HPV and HPV16 European variants in cervical and anal samples of HIV-seropositive women with normal Pap test results

Human Immunodeficiency Virus (HIV)-seropositive women are more likely to have anogenital cancer, and high risk-HPV (HR-HPV) infection is the main associated factor. Between August 2013 and December 2015, we conducted a descriptive study to determine the HPV genotypes and HPV16 variants in cervical and anal samples of HIV-seropositive women with a normal Pap test. The viral DNA was amplified by PCR using the PGMY09/11 set of primers. Reverse line blot (RLB), restriction fragment length polymorphism (RFLP) and sequencing assays were used to determine the HPV genotypes. HPV16 variants were identified by gene sequencing. We found a high frequency of HR-HPV (60.3%; 76/126) at the anogenital site among HIV-seropositive women and without association with anal intercourse. HPV16 and European variant predominated among the HR-HPV. Mixed infections with at least three different HPV types were common, particularly at the anal site. CD4+ T-cell counts below 500 cells/mm³, a HIV viral load above 50 copies/mL and an age of 18 to 35 years old were all related to HPV anal infection. Our study showed a high frequency of HR-HPV in both cervical and anal sites of women with negative cytology belonging to a risk group for the development of anogenital cancer.

Whole-Genome Analysis of Human Papillomavirus Types 16, 18, and 58 Isolated from Cervical Precancer and Cancer Samples in Chinese Women

Human papillomavirus (HPV) types 16, 18 and 58 are ranked the top three high-risk HPV types for cervical intraepithelial neoplasia (CIN) and invasive carcinoma. We aimed to evaluate the diversity of HPV16, HPV18, and HPV58 genetic variants by HPV capture technology combined with next generation sequencing. 295, 73, and 148 variations were observed in 51 HPV16, 7 HPV18, and 11 HPV58 genomes, respectively. HPV16 isolates were predominantly of the A variant lineage, and sublineage A4 (Asian) was the most common. However, there were no significant differences in the distribution of HPV16 A1-3 and A4 variants between CIN1-, CIN2/3, and cervical cancer groups. The 7 HPV18 genomes were assigned to the A3/A4 and A1 sublineages. Of the 11 HPV58 genomes, the most predominant variant sublineages were A2, followed by A1 and B2. The majority of HPV16/18 samples containing contiguous genomic deletions were found to harbor HPV integration. Some T-cell epitope sequences in HPV16 E6 and E7 showed considerable divergence from the prototype NC_001526, suggesting their importance in immunotherapy of HPV-associated carcinomas. In conclusion, sequence diversity and phylogenies of HPV16, 18, and 58 provide the basis for future studies of discrete viral evolution, epidemiology, pathogenicity, and the differences in response to vaccines.

Differential HPV16 variant distribution in squamous cell carcinoma, adenocarcinoma and adenosquamous cell carcinoma

Human Papillomavirus 16 (HPV16) causes 70% of invasive cervical cancers (ICC) worldwide. Interaction between HPV16 genetic diversity, host genetics and target tissue largely determine the chances to trigger carcinogenesis. We have analyzed the differential prevalence of viral variants in 233 HPV16-monoinfected squamous (SCC), glandular (ADC) and mixed (ADSC) ICCs from four continents, assessing the contribution of geographical origin and cancer histology. We have further quantified the contribution of viral variants and cancer histology to differences in age at tumor diagnosis. The model fitted to the data explained 97% of the total variance: the largest explanatory factors were differential abundance among HPV16 variants (78%) and their interaction with cancer histology (9.2%) and geography (10.1%). HPV16_A1-3 variants were more prevalent in SCC while HPV16_D variants were increased in glandular ICCs. We confirm further a non-random geographical structure of the viral variants distribution. ADCs were diagnosed at younger ages than SCCs, independently of the viral variant triggering carcinogenesis. HPV16 variants are differentially associated with histological ICCs types, and ADCs are systematically diagnosed in younger women. Our results have implications for the implementation of cervical cancer screening algorithms, to ensure proper early detection of elusive ADCs.

Transmission between Archaic and Modern Human Ancestors during the Evolution of the Oncogenic Human Papillomavirus 16

Every human suffers through life a number of papillomaviruses (PVs) infections, most of them asymptomatic. A notable exception are persistent infections by Human papillomavirus 16 (HPV16), the most oncogenic infectious agent for humans and responsible for most infection-driven anogenital cancers. Oncogenic potential is not homogeneous among HPV16 lineages, and genetic variation within HPV16 exhibits some geographic structure. However, an in-depth analysis of the HPV16 evolutionary history was still wanting. We have analyzed extant HPV16 diversity and compared the evolutionary and phylogeographical patterns of humans and of HPV16. We show that codivergence with modern humans explains at most 30% of the present viral geographical distribution. The most explanatory scenario suggests that ancestral HPV16 already infected ancestral human populations and that viral lineages co-diverged with the hosts in parallel with the split between archaic Neanderthal-Denisovans and ancestral modern human populations, generating the ancestral HPV16A and HPV16BCD viral lineages, respectively. We propose that after out-of-Africa migration of modern human ancestors, sexual transmission between human populations introduced HPV16A into modern human ancestor populations. We hypothesize that differential coevolution of HPV16 lineages with different but closely related ancestral human populations and subsequent host-switch events in parallel with introgression of archaic alleles into the genomes of modern human ancestors may be largely responsible for the present-day differential prevalence and association with cancers for HPV16 variants.

Human papillomavirus genotypes and HPV-16 variants distribution among Tunisian women with normal cytology and squamous intraepithelial lesions

BACKGROUND

Little is known about the epidemiological characteristics of papillomavirus (HPV) infection among North African countries. Herein, we conducted a molecular epidemiological study to investigate prevalence of HPV type and HPV-16 variants among cervical-screened unvaccinated Tunisian women.

METHODS

Cross-sectional study was performed on 494 Tunisian women visiting Women's Healthcare Centers. HPV-DNA detection was carried out on cervical samples using real-time polymerase chain reaction. HPV genotyping and HPV-16 variants were characterized by direct sequencing of L1 viral capsid gene.

RESULTS

The overall HPV prevalence was 34% (95% CI: 30-38%) with significantly higher prevalence among women with squamous intraepithelial lesions (SIL) than those with no intraepithelial lesions (NIL) 84% (95% CI: 76-92%) and 24.5% (95% CI: 20-29%) respectively. The distribution of HPV prevalence according to women's age shows a U-shaped curve and the highest HPV prevalence rates were observed among the youngest (≤25 years; 51.2%, 95% CI: 37-67%) and the oldest women (>55 years; 41.7%, 95% The HPV-16 prevalence was 32.8% (95% CI: 22-45%) among women with SIL and 9.2% (95% CI: 6-12%) among women with NIL. Whereas, the HPV-18 prevalence was 1.3% (95% CI: 0-5%) among women with SIL and 0.3% (95% CI: 0-1%) among women with NIL. Among HPV-16 positive women, European lineage (E) was identified as the predominant HPV-16 variant (85.7%, 95% CI: 76-95%). The frequency of E variant was lower among SIL than among NIL women (81%, 95% CI: 64-99%, and 88%, 95% CI: 77-100%, respectively). Conversely, the African-2 variant frequency was higher among SIL than among NIL women (18%, 95% CI: 1-36% and 6%, 95% CI: 2-14%, respectively). In multivariate analysis, young age was the only risk factor that is independently associated with HPV infection. Moreover, HPV infection and menopause were both found to be independently associated with SIL and HSIL.

CONCLUSION

HPV DNA testing should be proposed to young and menopausal Tunisian women. Considering HPV prevalence, only 13% of the Tunisian women could be protected by the bivalent HPV vaccine. These results may be helpful for designing an adapted HPV testing and vaccination program in Tunisia.

The Biological Impact of Genomic Diversity in Cervical Cancer Development

Human papillomaviruses (HPVs) are the etiologic agents of cervical cancer, the unique human neoplasia that has one single necessary cause. The diversity of HPVs is well described, with 200 HPV types existing as distinct taxonomic units and each receiving an Arabic number. On a clinical basis, they are usually grouped by their site of occurrence and disease associations. Those types inhabiting the anogenital mucosa are more intensively studied and further divided into cancer-associated HPVs, which are termed 'high risk', while those linked to benign proliferative lesions are assigned as 'low risk'. HPV16 is responsible for approximately 50% of all ICC cases, and paradoxically is one of the most prevalent types among healthy women. Longitudinal studies have shown that when an incidental HPV16 infection becomes persistent it will result in an enhanced risk for the development of high-grade lesions. However, it is unknown why some persistent, HPV16 infections (or infections by other HR-HPV types) progress to CIN3+ while most clear spontaneously. Several epidemiological investigations have focused on cofactors, from the most obvious such as cigarette and other carcinogenic exposures, to coinfections by other STDs such as chlamydia, with no significant findings. Thus, the current focus is on genomic variation from both virus and host. Such studies have been potentialized by the enormous technical advances in nucleic acid sequencing, allowing this relationship to be broadly interrogated. Corroborating subgenomic data from decades ago, an association between HPV16 lineages and carcinogenesis is being revealed. However, this effect does not seem to apply across female populations from different continents/ethnicities, again highlighting a role played by HPV16 adaptation and evasion from the host over time.

Genomic diversity and phylogenetic relationships of human papillomavirus 16 (HPV16) in Nepal

OBJECTIVES/BACKGROUND

Sequence variants in HPV16 confer differences in oncogenic potential; however, to date there have not been any HPV sequence studies performed in Nepal. The objective of this study was to characterize HPV16 viral genome sequences from Nepal compared to a reference sequence in order to determine their lineages. Additionally, we sought to determine if five High-grade Squamous Intraepithelial Lesion (HSIL) subjects were genetically distinct from the non-HSIL subjects.

METHODS

DNA was isolated from exfoliated cervical cells from 17 individuals in Nepal who were previously identified to be HPV16-positive. A custom HPV16 Ion Ampliseq panel of multiplexed degenerate primers was designed that generated 47 overlapping amplicons and covered 99% of the viral genome for all known HPV16 variant lineages. All sequence data were processed through a custom quality control and analysis pipeline of sequence comparisons and phylogenetic analysis.

RESULTS

There were high similarities across the genomes, with two major indels observed in the non-coding region between E5 and L2. Compared to the PAVE reference HPV16 genome, there were up to 9, 4, 38, 27, 8, 7, 52, and 32 nucleotide variants in the E6, E7, E1, E2, E4, E5, L2, and L1 genes in the Nepalese samples, respectively. Based on sequence variation, HPV16 from Nepal falls across the A, C, and D lineages in this study. We found no evidence of genetic distinctness between HSIL and non-HSIL subjects.

CONCLUSIONS

The evolutionary and pathological characteristics of the representative HPV16 genomes from Nepal seem similar to results from other parts of the world and provide the basis for further studies.

HPV16 variants distribution in invasive cancers of the cervix, vulva, vagina, penis, and anus

Human papillomavirus (HPV)16 is the most oncogenic human papillomavirus, responsible for most papillomavirus‐induced anogenital cancers. We have explored by sequencing and phylogenetic analysis the viral variant lineages present in 692 HPV16‐monoinfected invasive anogenital cancers from Europe, Asia, and Central/South America. We have assessed the contribution of geography and anatomy to the differential prevalence of HPV16 variants and to the nonsynonymous E6 T350G polymorphism. Most (68%) of the variance in the distribution of HPV16 variants was accounted for by the differential abundance of the different viral lineages. The most prevalent variant (above 70% prevalence) in all regions and in all locations was HPV16_A1‐3, except in Asia, where HPV16_A4 predominated in anal cancers. The differential prevalence of variants as a function of geographical origin explained 9% of the variance, and the differential prevalence of variants as a function of anatomical location accounted for less than 3% of the variance. Despite containing similar repertoires of HPV16 variants, we confirm the worldwide trend of cervical cancers being diagnosed significantly earlier than other anogenital cancers (early fifties vs. early sixties). Frequencies for alleles in the HPV16 E6 T350G polymorphism were similar across anogenital cancers from the same geographical origin. Interestingly, anogenital cancers from Central/South America displayed higher 350G allele frequencies also within HPV16_A1‐3 lineage compared with Europe. Our results demonstrate ample variation in HPV16 variants prevalence in anogenital cancers, which is partly explained by the geographical origin of the sample and only marginally explained by the anatomical location of the lesion, suggesting that tissue specialization is not essential evolutionary forces shaping HPV16 diversity in anogenital cancers.

HPV16 Sublineage Associations With Histology-Specific Cancer Risk Using HPV Whole-Genome Sequences in 3200 Women

BACKGROUND

HPV16 is a common sexually transmitted infection although few infections lead to cervical precancer/cancer; we cannot distinguish nor mechanistically explain why only certain infections progress. HPV16 can be classified into four main evolutionary-derived variant lineages (A, B, C, D) that have been previously suggested to have varying disease risks.

METHODS

We used a high-throughput HPV16 whole-genome sequencing assay to investigate variant lineage risk among 3215 HPV16-infected women. Using sublineages A1/A2 as the reference, we assessed all variant lineage associations with infection outcome over three or more years of follow-up: 1107 control subjects (

RESULTS

A4 sublineage was associated with an increased risk of cancer, specifically adenocarcinoma (OR = 9.81, 95% CI = 2.02 to 47.69, P = 4.7x10(-03)). Lineage B had a lower risk of CIN3 (OR = 0.51, 95% CI = 0. 28 to 0.91, P = 02) while lineage C showed increased risk (OR = 2.06, 95% CI = 1.09 to 3.89, P = 03). D2/D3 sublineages were strongly associated with an increased risk of CIN3 and cancer, particularly D2 (OR for cancer = 28.48, 95% CI = 9.27 to 87.55, P = 5.0x10(-09)). D2 had the strongest increased risk of glandular lesions, AIS (OR = 29.22, 95% CI = 8.94 to 95.51, P = 2.3x10(-08)), and adenocarcinomas (OR = 137.34, 95% CI = 37.21 to 506.88, P = 1.5x10(-13)). Moreover, the risk of precancer and cancer for specific variant lineages varied by a women's race/ethnicity; those women whose race/ethnicity matched that of the infecting HPV16 variant had an increased risk of CIN3 + (P < 001).

CONCLUSIONS

Specific HPV16 variant sublineages strongly influence risk of histologic types of precancer and cancer, and viral genetic variation may help explain its unique carcinogenic properties.

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Key Words Collapse

MESH Headings

• Adenocarcinoma/ethnology
• Adenocarcinoma/virology
• Adenocarcinoma in Situ/ethnology
• Adenocarcinoma in Situ/virology
• Adult
• Aftercare
• California/epidemiology
• Carcinoma/ethnology
• Carcinoma/virology
• Carcinoma, Squamous Cell/ethnology
• Carcinoma, Squamous Cell/virology
• Female
• Genome
• High-Throughput Nucleotide Sequencing
• Human papillomavirus 16/classification
• Human papillomavirus 16/genetics
• Human papillomavirus 16/pathogenicity
• Humans
• Middle Aged
• Papillomavirus Infections/ethnology
• Papillomavirus Infections/virology
• Phylogeny
• Precancerous Conditions/ethnology
• Precancerous Conditions/virology
• Risk Factors
• Uterine Cervical Neoplasms/ethnology
• Uterine Cervical Neoplasms/virology
• Young Adult
• Uterine Cervical Dysplasia/ethnology
• Uterine Cervical Dysplasia/virology

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Grants

• U01 CA078527 NCI NIH HHS

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Affiliation(s)

Lisa Mirabello Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Meredith Yeager Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Michael Cullen Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Joseph F Boland Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Zigui Chen Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Nicolas Wentzensen Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Xijun Zhang Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Kai Yu Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Qi Yang Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Jason Mitchell Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
David Roberson Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Sara Bass Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Yanzi Xiao Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Laurie Burdett Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Tina Raine-Bennett Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Thomas Lorey Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Philip E Castle Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Robert D Burk Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)
Mark Schiffman Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD (LM, MY, MC, JFB, NW, XZ, KY, QY, JM, DR, SB, LB, YX, MS); Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, MD (MY, MC, JFB, XZ, QY, JM, DR, SB, LB); Department of Microbiology, The Chinese University of Hong Kong, Hong Kong (ZC); Women's Health Research Institute, Division of Research, Kaiser Permanente Northern California, Oakland CA (TRB); Regional Laboratory, Kaiser Permanente Northern California, Oakland, CA (TL); Department of Epidemiology and Population Health, at Albert Einstein College of Medicine, Bronx, NY (PEC, RDB); Departments of Pediatrics; Microbiology & Immunology; and, Obstetrics, Gynecology and Women's Health, at Albert Einstein College of Medicine, Bronx, NY (RDB)

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Variants of human papillomaviruses 16 (HPV16) in Uigur women in Xinjiang, China

BACKGROUND

Persistent infection of high-risk human papillomaviruses 16 (HPV16) has been considered as the leading cause of cervical cancer. In this study we assessed HPV16 sequence variation and genetic diversity of HPV16 variants in cervical cancer in Uigur women in Xinjiang, China. We analyzed the nucleotide sequences of the open reading frames of E6 and E7, and part of the open reading frames of L1 of HPV16 in Uigur women.

METHODS

Biopsies of histologically confirmed HPV16 infections with cervical cancer were obtained from 43 Uigur women in Xinjiang, China. E6, E7 and L1 genes of HPV16 of all samples were amplified and sequenced; the sequences were used in phylogenetic analysis of HPV16 variants.

RESULTS

Our analysis revealed nine nucleotide changes in E6 (five changes), E7 (one change) and L1 (three changes) gene. The most frequently observed variations were T350G (79.1 %). One variation T295G (D64E) at E6 were detected in 6 cases (KT959536, KT959542, KT959546, KT959550, KT959553, KT959558). Deletion (464Asp) along with insertion (448Ser) were observed in L1 (100 %). Most variants were European lineage (97.7 %); only one belongs to Asia variants with common T178G (D25E) in E6 and A647G (N29S) in E7.

CONCLUSION

The most prevalent HPV16 variants in the Uigur women we studied were of the European lineage. Our results indicate that HPV16 European lineage may serve as a harmful factor associated with the development and progression of cervical cancer.

Genetic variability and lineage phylogeny of human papillomavirus type-16 and -53 based on the E6, E7, and L1 genes in Southwest China

Human papillomaviruses (HPVs) are circular double-stranded DNA viruses that are highly prevalent in the general population, and account for the cervical cancer burden in women worldwide. In this study, we analyzed HPV-16, the most prevalent type worldwide, and HPV-53, a possible high-risk type from infected women in Southwest China. To characterize mutations, intratypic variants, and genetic variability in the E6, E7, and L1 genes of HPV-16 (n=97) and HPV-53 (n=15), these genes were sequenced and submitted to GenBank. Phylogenetic trees were constructed using Bayesian trees, followed by secondary structure analysis and B-cell epitope prediction. Moreover, the selection pressures of the E6, E7, and L1 genes were estimated. In total, 27 novel variants of HPV-16 and 11 novel variants of HPV-53 were identified. In the HPV-16 E6-E7-L1 sequences, 73 nucleotide changes were observed with 40/73 being non-synonymous mutations (two in the alpha helix and five in the beta sheet) and 33/73 being synonymous. In the HPV-53 E6-E7-L1 sequences, 64 nucleotide changes were observed with 26/64 being non-synonymous mutations (three in the alpha helix and one in the beta sheet) and 38/64 being synonymous. Selective pressure analysis showed that most of these mutations did not reflect positive selection. The maximal divergence between any two variants within each gene of these two HPV types ranging from 0.94%(HPV-16 L1 gene)to 2.80%(HPV-53 E6 gene). Identifying new variants of HPV-16 and -53 from women in Southwest China may be helpful to design vaccines specifically for women in Southwest China and testing methods specifically for this region. The results of our study may contribute to future researches in diagnostic probes, vaccines improvement, or screening methods for a particular population.

Association between human papillomavirus type 16 E6 and E7 variants with subsequent persistent infection and recurrence of cervical high-grade squamous intraepithelial lesion after conization

The study aimed to detect the variants of human papillomavirus (HPV) type 16 E6 and E7 in patients with cervical high-grade squamous intraepithelial lesion (HSIL), and to determine the existence and recurrence of persistent infection after treatment with loop electrosurgical excision procedure (LEEP). Preoperatively collected cervical exfoliated cells from 100 HPV 16 positive HSIL patients enrolled in the study were used to test for E6 and E7 variants. Follow-ups which included TCT, HPV test, and colposcopy were performed every 3 months after the operation, and colposcopic biopsy and endocervical curettage were performed for patients with abnormalities. Patients were followed for 2 years, and recurrence was defined as detecting low-grade squamous intraepithelial lesion (LSIL) or relapse of HSIL in 1 year. In 81% of patients, the E6 variant was the Asian prototype (As.P), 14% of patients had the European variant, 2% had the European prototype (EP), and 3% had the African 1 variant (Af1). The HPV16 could be easily cleared by LEEP in patients with As.P. Persistent infection or recurrence was very rare in this group. The patients with European variants T350G or A442C had a significantly higher incidence of persistent and recurring HPV16 infection. In conclusion, (i) in most cases, As.P caused HSIL. (ii) The European variant E6 T350G/A442C may be associated with higher rates of recurring and persistent HPV16 infection after the LEEP. (iii) The E7 gene mutation may not be a risk factor for recurring HSIL caused by HPV16 or persistent infection. J. Med. Virol. 88:1982-1988, 2016. © 2016 Wiley Periodicals, Inc.

Complete Genome Sequences of Eight Human Papillomavirus Type 16 Asian American and European Variant Isolates from Cervical Biopsies and Lesions in Indian Women

Human papillomavirus type 16 (HPV16), a member of the Papillomaviridae family, is the primary etiological agent of cervical cancer. Here, we report the complete genome sequences of four HPV16 Asian American variants and four European variants, isolated from cervical biopsies and scrapings in India.

Dynamic response of HPV16/anti-HPV16 pairs with unbinding events studied by atomic force microscopy

This paper proposes an effective approach to distinguish whether samples include Human Papilloma virus type-16 (HPV16) by Atomic force microscopy (AFM). AFM is an important instrument in nanobiotechnology field. At first we identified the HPV16 by Polymerase chain reaction (PCR) analysis and Western blotting from specimen of the HPV patient (E12) and the normal (C2), and then we used an AFM to observe the surface ultrastructure by tapping mode and to measure the unbinding force between HPV16 coupled to an AFM tip and anti-HPV16 L1 coated on the substrate surface by contact mode. The experimental results by tapping mode show that the size of a single HPV viron was similar to its SEM image from the previous literatures; moreover, based on the purposed methods and the analysis, two obvious findings that we can determine whether or not the subject is a HPV patient can be derived from the results; one is based on the distribution of unbinding forces, and the other is based on the distribution of the stiffness. Furthermore, the proposed method could be a useful technique for further investigating the potential role among subtypes of HPVs in the oncogenesis of human cervical cancer.

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Human Papilloma virus type-16 (HPV16) particles were observed by AFM tapping mode and contact mode.

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This study develops a convenient procedure by AFM to check HPV16 samples under test.

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This procedure by AFM could be used to design the HPV16 biosensor.

Identification of novel human papillomavirus lineages and sublineages in HIV/HPV-coinfected pregnant women by next-generation sequencing

Infection by human papillomavirus (HPV) is a necessary condition for development of cervical cancer, and has also been associated with malignancies of other body anatomical sites. Specific HPV types have been associated with premalignant lesions and invasive carcinoma, but mounting evidence suggests that within-type lineages and sublineages also display distinct biological characteristics associated with persistent infections and evolution to cervical cancer. In the present study, we have assessed HPV multiple infection and variation from a cohort of highly susceptible, HIV(+) pregnant women using next-generation sequencing and an in-house pipeline for HPV full-length genome assembly. Seventy-two consensus sequences representing complete or near-complete (>97%) HPV genomes were assembled, spanning 28 different types. Genetic distance and phylogenetic analyses allowed us to propose the classification of novel HPV lineages and sublineages across nine HPV types, including two high-risk types. HPV diversity may be a hallmark of immunosuppressed patients upon HIV infection and AIDS progression.

Characterization of Intra-Type Variants of Oncogenic Human Papillomaviruses by Next-Generation Deep Sequencing of the E6/E7 Region

Different human papillomavirus (HPV) types are characterized by differences in tissue tropism and ability to promote cell proliferation and transformation. In addition, clinical and experimental studies have shown that some genetic variants/lineages of high-risk HPV (HR-HPV) types are characterized by increased oncogenic activity and probability to induce cancer. In this study, we designed and validated a new method based on multiplex PCR-deep sequencing of the E6/E7 region of HR-HPV types to characterize HPV intra-type variants in clinical specimens. Validation experiments demonstrated that this method allowed reliable identification of the different lineages of oncogenic HPV types. Advantages of this method over other published methods were represented by its ability to detect variants of all HR-HPV types in a single reaction, to detect variants of HR-HPV types in clinical specimens with multiple infections, and, being based on sequencing of the full E6/E7 region, to detect amino acid changes in these oncogenes potentially associated with increased transforming activity.

Analysis of human papillomavirus 16 variants and risk for cervical cancer in Chinese population

HPV16 is the most carcinogenic HPV type, but only a minority of HPV16 infections progress to cancer. Intratype genetic variants of HPV16 have been suggested to confer differential carcinogenicity. To investigate risk implications of HPV16 variants among Chinese women, a case-control study was conducted with 298 cervical cancer patients and 85 controls (all HPV16-positive). HPV16 isolates were predominantly of the A variant lineage, and variants of A4 (previously named "Asian") sublineage were common. A4/Asian variants were significantly associated with increased risk of cervical cancer compared to A1-3 (OR=1.72, 95% CI=1.04-2.85). Furthermore, a meta-analysis including 703 cases and 323 controls from East Asia confirmed the association (OR=2.82, 95% CI=1.44-5.52). In conclusion, A4 variants appear to predict higher risk of cervical cancer among HPV16-positive women, which may provide clues to the genetic basis of differences in the carcinogenicity of HPV16 variants.

Genetic diversity of HPV16 and HPV18 in Brazilian patients with invasive cervical cancer

Cervical cancer is the fourth most common cancer among women, and ∼70-80% of these cancers are associated with two human papillomavirus types: HPV16 and HPV18. Several studies have reported that intra-type diversity is associated with the progression of infection to invasive cancer. Herein, we report the genetic diversity of HPV16 and HPV18 in a cohort of 594 Brazilian women with invasive cervical cancer and describe the prevalence of lineages and intra-type diversity prior to the implementation of the public immunization program in Brazil. HPV detection and genotyping were performed using PCR, PGMY/GP primers, and DNA extracted from fresh tumors. The HPV16 (378 women) and HPV18 (80 women) lineages were identified by PCR and sequencing of the LCR and E6 fragments, followed by SNV comparison and phylogenetic analysis. In our cohort, was found a higher frequency of the lineage A (in 217 women), followed by lineage D (in 97 women) and lineages B and C (in 10 women each) for HPV16; and a higher frequency of lineage A (in 56 women) followed by lineage B (in 15 women) in HPV18. The genetic diversity of HPV16 indicated a recent expansion of specific variants or a selective advantage that is associated with invasive cancer; this pattern was not observed for HPV18.

Distribution of human papillomavirus type 16 variants in Lithuanian women with cervical cancer

BACKGROUND AND OBJECTIVE

Cervical cancer usually is caused by HPV 16. However, HPV 16 varies within type; different genotypes are described as prototype or variants. Prevalence of different variants differ according the geographic regions and has an unequal impact for cervical cancer development. Our study aimed to identify which variant of HPV 16 was most prevalent in biological samples taken from Lithuanian women with cervical cancer.

MATERIALS AND METHODS

A total of 122 HPV 16 positive cervical samples (invasive cancer and cervical intraepithelial neoplasia) were investigated and sequenced to identify different variants. HPV 16 was detected using type specific PCR, exact sequence of the virus was obtained by viral DNA sequencing.

RESULTS

Adequate HPV sequence was detected in 106 cases from 122 (86.9% of all cases). After histological confirmation, 96 cases were included in the final analysis. In 33 cases (34.4%) HPV 16 prototype was detected; in 50 cases (52.1%), L83V variant; and in remaining 13 cases (13.5%), multivariant of HPV 16. The frequency of L83V variant in invasive cancer and carcinoma in situ samples was the same (66.7% and 62.0%, respectively; P=0.696). Of analyzed multivariants, 10 were attributed to the European phylogenetic line; 1, to the North American, and 1, to the Asian-American. One sample was not attributed to any of the known phylogenetic lines.

CONCLUSIONS

The European HPV 16 L83V variant is usually associated with high risk of cervical cancer among women. However, statistically significant difference was not achieved when comparing difference of L83V variants between investigated groups and in HPV 16 L83V variant and prototype distribution in CIN3/Ca in situ and cancer.

Deep sequencing of HPV16 genomes: A new high-throughput tool for exploring the carcinogenicity and natural history of HPV16 infection

For unknown reasons, there is huge variability in risk conferred by different HPV types and, remarkably, strong differences even between closely related variant lineages within each type. HPV16 is a uniquely powerful carcinogenic type, causing approximately half of cervical cancer and most other HPV-related cancers. To permit the large-scale study of HPV genome variability and precancer/cancer, starting with HPV16 and cervical cancer, we developed a high-throughput next-generation sequencing (NGS) whole-genome method. We designed a custom HPV16 AmpliSeq™ panel that generated 47 overlapping amplicons covering 99% of the genome sequenced on the Ion Torrent Proton platform. After validating with Sanger, the current "gold standard" of sequencing, in 89 specimens with concordance of 99.9%, we used our NGS method and custom annotation pipeline to sequence 796 HPV16-positive exfoliated cervical cell specimens. The median completion rate per sample was 98.0%. Our method enabled us to discover novel SNPs, large contiguous deletions suggestive of viral integration (OR of 27.3, 95% CI 3.3-222, P=0.002), and the sensitive detection of variant lineage coinfections. This method represents an innovative high-throughput, ultra-deep coverage technique for HPV genomic sequencing, which, in turn, enables the investigation of the role of genetic variation in HPV epidemiology and carcinogenesis.

The human papillomavirus 16 European-T350G E6 variant can immortalize but not transform keratinocytes in the absence of E7

Human papillomavirus type 16 is commonly implicated in HPV-related cancers. However, only a small number of infected individuals progress to this stage. Epidemiological evidence demonstrated that oncogenic risk is population-specific and variations within the viral oncogene, E6, have been suggested to play a role in these findings. Of focus in this study is the European-T350G variant, which is characterized by an L>V amino acid substitution at residue 83 of the prototype E6 protein. To elucidate the functional effects of this polymorphism, we followed keratinocytes transduced with E-T350G E6 for over 60 passages and compared them to keratinocytes transduced, in parallel, with prototype or Asian-American (Q14H/L83V/H78Y) E6. We found that although E-T350G E6 immortalized transduced keratinocytes in the absence of E7, these cells were not fully transformed. We also found that E-T350G down-regulated E-cadherin compared to the other variants, providing a possible link between its population-based oncogenicity and host genetic variations.

Human Papillomavirus 16 Variants May Be Identified by E6 Gene Analysis

Aims: The aims of the study were (1) to characterize the genetic variability of human papillomavirus (HPV) genotype 16 in the E6 region when this genotype is present in multiple infection samples, (2) to assess the prevalence of variants in our region and (3) to analyze the relationship between variants, patients' ages and pathology. Methods: The Clinical Microbiology and Infection Control Department analyzed samples which were positive for genotype 16 and other genotypes from 2007 to 2013. Variants were assigned to European, Euro-German, Asian, Asian-American or African lineage by sequence analysis. The relationship among variants, age and different types of lesion was studied. Results: In HPV-16 sequence analysis, the European variant was detected in 85.10% of samples, the Asian-American in 7.80%, the African in 4.25% and the Euro-German in 2.83% of specimens. Sequence genetic variability showed 16 nucleotide substitutions. Moreover, non-European variants were mainly found in old women and in isolates from high-grade squamous intraepithelial lesions since European variants were mainly detected in negative cytologies. Conclusion: Multiple infections may take effect on nucleotide substitution and the appearance of recombinant samples. Single gene analysis makes it impossible to detect recombination which has a great influence on drug response and vaccine strategies. Thus, E6 gene analysis would be enough to identify HPV-16 intratypic variants but not to confirm the results.

Genetic variability in E6 and E7 oncogenes of human papillomavirus Type 16 from Congolese cervical cancer isolates

Background

The molecular epidemiological studies showed that some variants of HPV-16, distributed geographically, would present a higher risk of causing cervical cancer. This study aimed to analyze nucleotide changes of HPV-16 E6 and E7 genomic regions from infected Southwestern Congolese women.

Methods

DNA of twenty HPV-16 isolates was analyzed by amplifying the E6 and E7 genes using type-specific primers PCR and direct sequencing. The sequences obtained were aligned with the HPV-16 GenBank reference sequences.

Results

Thirteen (65.0%) out of 20 DNA-samples were successfully amplified. Genetic analysis revealed 18 and 4 nucleotide changes in E6 and E7 genomic regions respectively. The most frequently observed nucleotide variations were the missense C143G, G145T and C335T in E6 (100%), leading to the non-synonymous amino acid variation Q14D and H78Y. E7 genomic region was found to be highly conserved with two most common T789C and T795G (100%) silent variations. All HPV-16 variants identified belonged to the African lineage: 7 (53.8%) belonged to Af-1 lineage and 6 (46.1%) to Af-2 lineage. The missense mutation G622A (D21N) in the E7 region seems to be described for the first time in this study.

Conclusion

This study reported for the first time the distribution of HPV-16 E6 and E7 genetic variants in infected women from southwest Congo. The findings confirmed almost ascendancy of the African lineage in our study population.

Genetic variations of human papillomavirus type 16: implications for cervical carcinogenesis

Human papillomaviruses (HPVs) are the causative agent of cervical cancer, and among approximately 15 high-risk genotypes, HPV16 accounts for more than half the cases of cervical cancer worldwide. Recent progress in determining HPV genomic sequences from clinical samples has revealed a wide variety in HPV16 genome sequences, and has allowed for comprehensive classification of intratype HPV16 variants. These consist of four variant lineages containing nucleotide variations in 1.0%-10.0% of the complete viral genome sequence. Epidemiological data suggest that the non-European-Asian lineages of HPV16 entail a higher risk of progression to invasive cervical cancer than the European-Asian lineage. Deep sequencing analysis has recently demonstrated that HPV16 genome sequences are highly homogeneous in individual clinical specimens compared with those of RNA viruses. However, an extremely sensitive PCR method, differential DNA denaturation PCR, has detected hypermutations from C to T or G to A in the E2 gene and the long control region of the HPV16 genome, which suggests the involvement of cellular apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) proteins in this hypermutation. The quasispecies status of the HPV16 genome in the infected cervix may affect the development of cervical cancer and warrants further investigation.

Association of human papillomavirus 16 E6 variants with cervical carcinoma and precursor lesions in women from Southern Mexico

Background

HPV 16 is the cause of cervical carcinoma, but only a small fraction of women with HPV infection progress to this pathology. Besides persistent infection and HPV integration, several studies have suggested that HPV intratype variants may contribute to the development of cancer. The purpose of this study was to investigate the nucleotide variability and phylogenetically classify HPV 16 E6 variants circulating over a period of 16 years in women from Southern Mexico, and to analyze its association with precursor lesions and cervical carcinoma.

Methods

This study was conducted in 330 cervical DNA samples with HPV 16 from women who were residents of the State of Guerrero, located in Southern Mexico. According of cytological and/or histological diagnosis, samples were divided into the following four groups: no intraepithelial lesion (n = 97), low-grade squamous intraepithelial lesion (n = 123), high-grade squamous intraepithelial lesion (n = 19) and cervical carcinoma (n = 91). HPV 16 E6 gene was amplified, sequenced and aligned with reference sequence (HPV 16R) and a phylogenetic tree was constructed to identify and classify HPV 16 variants. Chi squared was used and data analysis and statistics were done with SPSS Statistics and STATA softwares.

Results

Twenty seven HPV 16 E6 variants were detected in women from Southern Mexico, 82.12% belonged to the EUR, 17.58% to AA1 and 0.3% to Afr2a sublineages. The most common was E-G350 (40%), followed by E-prototype (13.03%), E-C188/G350 (11.82%), AA-a (10.61%), AA-c (6.07%) and E-A176/G350 (5.15%). Eight new E6 variants were found and 2 of them lead to amino acid change: E-C183/G350 (I27T) and E-C306/G350 (K68T). The HPV 16 variant that showed the greatest risk of leading to the development of CC was AA-a (OR = 69.01, CI = 7.57-628.96), followed by E-A176/G350 (OR = 39.82, CI = 4.11-386.04), AA-c (OR = 21.16, CI 2.59-172.56), E-G350 (OR = 13.25, CI = 2.02-87.12) and E-C188/G350 (OR = 10.48, CI = 1.39-78.92).

Conclusions

The variants more frequently found in women with cervical carcinoma are E-G350, AA-a, AA-c, E-C188/G350 and E-A176/G350. All of them are associated with the development of cervical carcinoma, however, AA-a showed the highest association. This study reinforces the proposal that HPV 16 AA-a is an oncogenic risk for cervical carcinoma progression in Mexico.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-015-0242-3) contains supplementary material, which is available to authorized users.

Genetic characterization and clinical implications of human papillomavirus type 16 (HPV16) variants from northeastern Argentina

BACKGROUND

Human papillomavirus type 16 (HPV16) plays a central role in the development of cervical cancer. Worldwide studies indicate the existence of HPV16 variants that show different geographic distributions and oncogenic potential.

OBJECTIVE

Our goal was to describe the genetic variation of HPV16 isolates identified in urban women with different grades of cervical lesions living in northeastern Argentina.

STUDY DESIGN

We analyzed 116 HPV16-positive cervical samples (16 NLIM, 62 L-SIL, 16 H-SIL and 22 cervical cancer) from patients attending health centers in Misiones (Argentina) during 2006-13. HPV16 isolates were genetically characterized through PCR amplification and direct sequencing of 364 bp within the long control region, and the resulting sequences classified into variants based on phylogenetic analysis (lineages A, B, C and D). A potential association between HPV16 variants and lesion grade was evaluated through an odds ratio (OR) test. A temporal framework for the origin of HPV16 variants was assessed through coalescence analysis (BEAST v 1.7.5).

RESULTS

Phylogenetic analysis of HPV16 sequences showed that 92.1% of the samples clustered with lineage A, and 6.9% to lineage D. HPV16 variants from lineage D were more frequently associated with high-grade lesions and cancer (HSIL+) than lineage A variants at an OR of 13.8 (1.6-117.0). The time to most common recent ancestor (tMCRA) of all variants was 119,103 years before present (HPD 95%=48,486-197,239), a date consistent with the time frame for modern human evolution.

CONCLUSION

Our results suggest that HPV16 variants from lineage D may represent an additional risk factor for the development of cervical cancer in women living in northeastern Argentina. This study provides new information about viral isolates present in Argentina that will contribute to the monitoring of HPV16 infection in the vaccine era.

Unexpected inverse correlation between Native American ancestry and Asian American variants of HPV16 in admixed Colombian cervical cancer cases

BACKGROUND

European (E) variants of HPV 16 are evenly distributed among world regions, meanwhile Non-European variants such as European-Asian (EAs), Asian American (AA) and African (Af) are mostly confined to Eastern Asia, The Americas and African regions respectively. Several studies have shown that genetic variation of HPV 16 is associated with the risk of cervical cancer, which also seems to be dependent on the population. This relationship between ethnicity and variants have led to the suggestion that there is co-evolution of variants with humankind. Our aim was to evaluate the relationship between the individual ancestry proportion and infection with HPV 16 variants in cervical cancer.

METHODS

We examined the association between ancestry and HPV 16 variants in samples of 82 cervical cancer cases from different regions of Colombia. Individual ancestry proportions (European, African and Native American) were estimated by genotyping 106 ancestry informative markers. Variants were identified by PCR amplification of the E6 gene, followed by reverse line blot hybridization (RLB) with variants specific probes.

RESULTS

Overall European (E) and Asian American (AA) variants frequency was 66.5% and 33.5% respectively. Similar distribution was observed in cases with higher proportions of European or African ancestry. A higher Native American ancestry was significantly associated with higher frequency of E variants (median ancestry>23.6%, Age and place of birth adjusted OR: 3.55, 95% CI: 1.26-10.03, p=0.01). Even further, an inverse geographic correlation between Native American ancestry and frequency of infections with AA variants was observed (ρ=-0.825, p=0.008). Regions with higher proportion of Native American ancestry had a lower frequency of AA variants of HPV 16.

CONCLUSIONS

This study suggests replacement of AA variants by E variants of human papillomavirus 16 in cervical cancer cases with high Native American ancestry.

Human papillomavirus induced transformation in cervical and head and neck cancers

Human papillomavirus (HPV) is one of the most widely publicized and researched pathogenic DNA viruses. For decades, HPV research has focused on transforming viral activities in cervical cancer. During the past 15 years, however, HPV has also emerged as a major etiological agent in cancers of the head and neck, in particular squamous cell carcinoma. Even with significant strides achieved towards the screening and treatment of cervical cancer, and preventive vaccines, cervical cancer remains the leading cause of cancer-associated deaths for women in developing countries. Furthermore, routine screens are not available for those at risk of head and neck cancer. The current expectation is that HPV vaccination will prevent not only cervical, but also head and neck cancers. In order to determine if previous cervical cancer models for HPV infection and transformation are directly applicable to head and neck cancer, clinical and molecular disease aspects must be carefully compared. In this review, we briefly discuss the cervical and head and neck cancer literature to highlight clinical and genomic commonalities. Differences in prognosis, staging and treatment, as well as comparisons of mutational profiles, viral integration patterns, and alterations in gene expression will be addressed.

Prevalence of HPV 16 and HPV 18 lineages in Galicia, Spain

Genetic variants of human papillomavirus types 16 and 18 (HPV16/18) could differ in their cancer risk. We studied the prevalence and association with high-grade cervical lesions of different HPV16/18 variant lineages in a case-control study including 217 cases (cervical intraepithelial neoplasia grade 2 or grade 3 or worse: CIN2 or CIN3+) and 116 controls (no CIN2 or CIN3+ in two-year follow-up). HPV lineages were determined by sequencing the long control region (LCR) and the E6 gene. Phylogenetic analysis of HPV16 confirmed that isolates clustered into previously described lineages: A (260, 87.5%), B (4, 1.3%), C (8, 2.7%), and D (25, 8.4%). Lineage D/lineage A strains were, respectively, detected in 4/82 control patients, 19/126 CIN3+ cases (OR = 3.1, 95%CI: 1.0–12.9, p = 0.04), 6/1 glandular high-grade lesions (OR = 123, 95%CI: 9.7–5713.6, p<0.0001), and 4/5 invasive lesions (OR = 16.4, 95%CI: 2.2–113.7, p = 0.002). HPV18 clustered in lineages A (32, 88.9%) and B (4, 11.1%). Lineage B/lineage A strains were respectively detected in 1/23 control patients and 2/5 CIN3+ cases (OR = 9.2, 95%CI: 0.4–565.4, p = 0.12). In conclusion, lineages A of HPV16/18 were predominant in Spain. Lineage D of HPV16 was associated with increased risk for CIN3+, glandular high-grade lesions, and invasive lesions compared with lineage A. Lineage B of HPV18 may be associated with increased risk for CIN3+ compared with lineage A, but the association was not significant. Large well-designed studies are needed before the application of HPV lineage detection in clinical settings.