Meta-analysis on prevalence and attribution of human papillomavirus types 52 and 58 in cervical neoplasia worldwide

Associations of Single Versus Multiple Human Papillomavirus Infections With the Prevalence of Cervical Intraepithelial Neoplasia 2/3 and Squamous Cell Carcinoma Lesions: Human Papillomavirus Type-Specific Attribution

The risk of developing cervical squamous lesions in women with multiple high-risk human papillomavirus (hrHPV) infections is uncertain. The aim of this retrospective study was to investigate the type-specific attribution and phylogenetic effects of single and multiple hrHPV subtypes in cervical squamous lesions. All cases with cervical histopathologic diagnosis and human papillomavirus (HPV) genotyping results in the 6 months preceding biopsy from October 2018 to December 2022 were studied and analyzed. Over the study period, 70,361 cases with histopathologic follow-up and prior HPV genotyping were identified. The hrHPV-positive rate was 55.6% (39,104/70,361), including single hrHPV detected in 27,182 (38.6%), 2 types of hrHPV detected in 8158 (11.6%), and 3 types of hrHPV detected in 2486 (3.5%). Among 16,457 cases with a histologically diagnosed squamous lesion (cervical intraepithelial neoplasia 1: 11411; cervical intraepithelial neoplasia 2/3: 4192; squamous cell carcinoma: 854 cases), the prevalence of single hrHPV infection increased, but the rate of multiple concomitant hrHPV infections showed negative association as the degree of squamous lesions increased. Among women with a single HPV16 infection, cervical intraepithelial neoplasia 2/3 and squamous cell carcinoma (CIN2+) diagnostic rate was 30.6%, and it increased to 47.6% when coinfected with HPV33 (P < .001) but significantly decreased when coinfected with all other hrHPV types (P < .05). By comparing CIN2+ diagnostic rates in 40 most common 2 types of hrHPV infections with related single hrHPV infection, CIN2+ rates were decreased in 12 combinations (30.0%), equivalent in 26 combinations (65.0%), and increased in 2 combinations (5.0%). The cases with 3 types of HPV infections reduced the risk for CIN2+ compared with related single HPV infections. HPV16+52+53, HPV16+52+68, HPV16+52+51, HPV16+39+52, and HPV16+58+53 significantly decreased the risk of CIN2+ compared with HPV16 single infection (P < .05). This study demonstrates that multiple hrHPV infections are not associated with cumulatively higher risk for CIN2+ development, suggesting that oncogenic progression of multiple hrHPV-associated cervical squamous lesions is neither synergistic nor a cumulative effect at the phylogenetic level, possibly a way of competitive interference.

Changes in the Incidence and Human Papillomavirus-Positive Portion of Oropharyngeal Squamous Cell Carcinoma in Hong Kong

The incidence of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is rising in the West, but little is known in Asia. This study elucidated changes in the incidence and HPV-positive portion of OPSCC in Hong Kong. Data from population-based cancer registry were used to analyze the incidence of OPSCC in association with other head and neck cancers. Archived tumor tissues were tested for HPV. From 1986 to 2020, there was a marked decrease in the incidence of nasopharyngeal and laryngeal cancers, but a persistent increase in OPSCC from 36 cases in 1986 to 116 cases in 2020. The average positive rate for high-risk HPV was 36.1% (112/310) among OPSCC diagnosed in 2010-2020. The HPV-positive rate in recent years was significantly higher than earlier cases (tonsil SCC: 64.7% (55/85) in 2016-2020 vs. 40.4% (19/47) in 2010-2015, p = 0.007). Patients with HPV-positive tonsil cancers were significantly younger than those negative (mean [SD]: 58.9 [9.9] vs. 64.3 [13.3] years, p = 0.006), but no significant difference was observed between genders. A persistent increase in the incidence of oropharyngeal cancer over the last few decades was observed in Hong Kong, which can be explained by the remarkable increase in HPV-positive tonsil cancers.

Relative distribution of HPV genotypes in histological cervical samples and associated grade lesion in a women population over the last 16 years in Burgundy, France

Human papillomavirus is a predominant sexually transmitted viral pathogen. Our objective was to analyze the relative distribution of genotypes over time and to determine the genotypes associated with adverse clinical lesions. The study was based on data from adult women with cytological abnormalities from whom histological samples were obtained from 2005 to 2021. HPV genotyping was performed using PCR and INNO-LiPA assay (Fujirebio). Among the 1,017 HPV-positive biopsies, 732 (72%) were infected with a single HPV genotype and 285 (28%) were infected with several HPV genotypes. Most of the infections involved the high-risk genotypes 16, 31, and 52. Throughout the study period, HPV 16 was the most encountered genotype (541, 53.2%), while HPV 18 was rather under-represented (46, 4.5%), especially in invasive cervical carcinoma. HVP52 (165, 16.2%) was detected mainly from 2008 to 2014, and its distribution reached 19.7% in 2011. Such epidemiological data underlines the possibility of an emergence of a high-risk genotype. The most detected low-risk HPV in combination with high-risk HPV was HPV 54 in 6.5% of samples. Monoinfection by HPV 16 led statistically more often to severe lesions than multi-infection involving HPV 16 (p < 0.001), while for HPV 52, 31 or 33, multi-infections were significantly associated with severe lesions (p < 0.001 for each of these three genotypes). HPV 16 was involved in 55.2% of high-grade lesions and in situ carcinoma and 76.3% of invasive carcinomas. In severe lesions, HPV 16 participation was predominant, whereas diverse genotypes were seen in low-grade lesions. Importantly, we observed that high-risk genotypes, for example HPV 52, can emerge for a few years then decrease even without vaccine pressure.

Distribution of human papilloma virus genotypes and treatment outcomes in definitive radiotherapy for cervical cancer

Most oncogenic human papilloma virus (HPV) genotypes stratify into two species, α-7 HPV and α-9 HPV. There are several studies that evaluate the relationship between HPV species and treatment outcomes and reports that HPV species is prognostic. The HPV genotyping was conducted using biopsy specimens which had been stored in these studies. We conducted the study using the HPV test performed by cytology specimens which is less invasive and more useful in clinical settings. This study enrolled 46 patients who received HPV genotyping before the definitive radiotherapy. The results of the HPV genotyping were classified into HPVα-7, HPVα-9 and negatives. Of the 46 patients, 10 were positive for HPVα-7, 21 positive for HPVα-9 and 15 were negative. The median follow-up period was 38 months (range 4-142). The HPVα-7, HPVα-9 and negative groups showed the 3-year overall survival (OS; 59.3%, 80.4% and 72.2% [P = 0.25]); local control (LC; 67.5%, 81% and 80% [P = 0.78]); pelvic control (PC) (50%, 81% and 72.7% [P = 0.032]); pelvic lymph node (PLN) control (78.7%, 95% and 92.3% [P = 0.012]); distant metastasis free (DMF) survival (50%, 75.4% and 42.8% [P = 0.098]); and progression free survival (PFS) rate of patients (30%, 66.7% and 38.9% [P = 0.085]), respectively. Patients with HPVα-7 showed statistically significant poorer PC than the HPVα-9 group, in multivariate analysis. This result is consistent with previous studies for HPV positive patients. The HPV negativity rate was higher in this study than in other studies and further work on this may be needed for clinical use.

Cost-Effectiveness Analysis of HPV Extended versus Partial Genotyping for Cervical Cancer Screening in Singapore

Human papillomavirus (HPV) partial genotyping (PGT) identifies HPV16 and HPV18 individually, alongside 12 other high-risk HPV genotypes (hrHPV) collectively. HPV extended genotyping (XGT) identifies four additional hrHPV individually (HPV31, 45, 51, and 52), and reports the remaining eight in three groups (HPV33|58; 56|59|66; 35|39|68). Quality-adjusted life years (QALY), health care resource use, and costs of XGT were compared to PGT for cervical cancer screening in Singapore using DICE simulation. Women with one of the three hrHPV identified by XGT (HPV35|39|68; 56|59|66; 51), and atypical squamous cells of undetermined significance (ASCUS) on cytology, are recalled for a repeat screening in one year, instead of undergoing an immediate colposcopy with PGT. At the repeat screening, the colposcopy is performed only for persistent same-genotype infections in XGT, while with PGT, all the women with persistent HPV have a colposcopy. Screening 500,122 women, aged 30-69, with XGT, provided an incremental cost-effectiveness ratio (ICER) versus PGT of SGD 16,370/QALY, with 7130 (19.4%) fewer colposcopies, 6027 (7.0%) fewer cytology tests, 9787 (1.6%) fewer clinic consultations, yet 2446 (0.5%) more HPV tests. The XGT ICER remains well below SGD 100,000 in sensitivity analyses, (-SGD 17,736/QALY to SGD 50,474/QALY). XGT is cost-effective compared to PGT, utilizes fewer resources, and provides a risk-based approach as the primary cervical cancer screening method.

Characteristics of human papillomavirus infection among females and the genetic variations of HPV18 and HPV58 in Henan province, China

The present study aims to investigate the genotype distribution of Human papillomavirus (HPV) and variations of HPV18 and HPV58 infection among 6538 females in Luoyang city during 2019-2021. The overall positive rate of females with HPV infection was 12.34%, with 9.74% were infected with single HPV and 2.60% with multiple HPVs. The prevalent rate of high-risk HPV (HR-HPV) was 9.85% and the top five HR-HPV genotypes were HPV52 (1.94%), HPV16 (1.93%), HPV58 (1.48%), HPV51 (1.02%) and HPVV39 (0.99%). Two peaks of HPV infections rates were observed in females aged ≤ 20 and 61-65 years old. To characterize mutations, 39 HPV18 and 56 HPV58 L1, E6 and E7 genes were sequenced and submitted to GenBank. In the HPV18 E6-E7-L1 sequences, 38 nucleotides changes were observed with 10/38 were non-synonymous mutations (5 in E6 gene, 1 in E7 gene and 4 in L1 gene). In the HPV58 E6-E7-L1 sequences, 53 nucleotides changes were observed with 23/53 were non-synonymous mutations (3 in E6 gene, 5 in E7 gene and 15 in L1 gene). Phylogenetic analysis based on L1 gene showed that 92.3% (36/39) of HPV18 isolates fell into sublineage A1 and 7.7% (3/39) belonged to A5. For HPV58, 75.0% (42/56) isolates belonged to sublineage A1 and 25.0% (14/56) were sublineage A2. There was no association between amino mutation and cervical lesions. The present study provides basic information about the distribution, genotypes and variations of HPV among females population in Luoyang city, which would assist in the formulation of HPV screening and vaccination programs and preventive strategies for HPV-attributable cancer in this region.

Prevalence of Human Papillomavirus Among Chinese Han and Mongols Minority Women in Inner Mongolia, China: Reflected by Self-Collected Samples in CHIMUST

Background

The disparities of hr-HPV infection among races/ethnicities have not been fully discussed. This study aimed to investigate the difference of hr-HPV infection between Chinese Han and Mongols minority women in Inner Mongolia.

Methods

Genotyping and histopathology data of Chinese Han and Mongols minority women in Inner Mongolia from Chinese Multi-Center Screening Trial were used to analyze the hr-HPV prevalence, and type-specific distribution in abnormal pathology results.

Results

The hr-HPV infection rates of Han women was 15.9% while of Mongols was 21.6% (P < 0.001). The most prevalent genotypes in Han women were ranked as HPV-16,−52,−18/-58,−31/-39, and−59 while in Mongols were−16,−31,−58,−18 and−52. When analyzing the age-specific of hr-HPV infection, two peaks were found at age of 40–44 (20.5%) and 55–59 (23.5%) years in Han women while three peaks were observed at age of 30–34 (22.1%), 45–49 (22.9%), and 55–59 (31.8%) years, respectively, in Mongols. HPV-16 accounting for 62.5 and 53.8% of the CINII+ in Han and Mongols, respectively.

Conclusion

The prevalence of hr-HPV was significantly different between the Han and Mongols minority women in Inner Mongolia, races/ethnicities background should be taken into consideration for the refinement of cervical cancer screening strategies and vaccine implementation in China.

Cervical Precancers and Cancers Attributed to HPV Types by Race and Ethnicity: Implications for Vaccination, Screening, and Management

BACKGROUND

Racial and ethnic variations in attribution of cervical precancer and cancer to HPV types may result in different HPV vaccine protection, screening test coverage, and clinical management.

METHODS

Pooling data from seven U.S. studies, we calculated the proportional attribution of precancers and cancers to HPV types using HPV DNA typing from diagnosis. All statistical tests were 2-sided.

RESULTS

For all racial and ethnic groups, most cervical intraepithelial neoplasia grade 3 (CIN3) (n = 5,526) and squamous cell carcinoma (SCC) cases (n = 1,138) were attributed to types targeted by the 9-valent vaccine. A higher proportion of CIN3s were attributed to non-vaccine HPV types among non-Hispanic Black women (15.8%) compared with non-Hispanic Asian or Pacific Islander (9.7%, P=.002), non-Hispanic White (9.2%, P<.001), and Hispanic women (11.3%, P=.004). The proportion of SCCs attributed to 9-valent types was similar by race and ethnicity (90.4%-93.8%, P = .80). A higher proportion of CIN3s were attributed to non-vaccine HPV35 among non-Hispanic Black (9.0%) compared with non-Hispanic Asian or Pacific Islander (2.2%), non-Hispanic White (2.5%), and Hispanic women (3.0%, all P<.001). Compared with CIN3, the proportion of SCCs attributed to HPV35 among Non-Hispanic Black women (3.2%) was lower and closer to other groups (0.3%-2.1%, P = .70).

CONCLUSION

The 9-valent HPV vaccine will prevent nearly all cervical precancers and invasive cancers among major racial and ethnic groups in the United States. Adding HPV35 to vaccines could prevent a small percentage of CIN3s and SCCs, with greater potential impact for CIN3s among Black women. HPV screening tests target high-risk HPV types, including HPV35. Future genotyping triage strategies could consider the importance of HPV35 and other HPV16 related types.

Possible different genotypes for human papillomavirus vaccination in lower middle-income countries towards cervical cancer elimination in 2030: a cross-sectional study

Purpose

Human papillomavirus (HPV) genotype and age distribution of HPV infection were crucial for the national vaccination and screening program planning. However, there was a limited study providing these data in the normal cervix population. This study aimed to explore the HPV genotypes profile of women with clinically normal cervix based on Visual Inspection of Acetic Acid (VIA) test.

Materials and Methods

A 7-year cross-sectional study was conducted from 2012 to 2018 in private and public health care centers in Jakarta. Subjects were recruited consecutively. Data were collected by anamnesis, VIA, and HPV DNA test using the polymerase chain reaction (PCR; SPF10-DEIA-LiPA25) method. HPV genotyping procedures include DNA extraction, PCR (SPF10-DEIA-LiPA25) using the HPV XpressMatrix kit (PT KalGen DNA, East Jakarta, Indonesia), and hybridization. The IBM SPSS ver. 20.0 (IBM Corp., Armonk, NY, USA) were used to analyze the data.

Results

A total of 1,397 subjects were collected. Positive HPV-DNA tests were found in 52 subjects (3.7%); 67% were single and 33% were multiple HPV infections. HPV 52 was the most frequently detected HPV genotype, followed by HPV 39, 16, 18 74, 44, 31, 54, and 66, respectively. The highest HPV infections in this population were in the 31–40 and 41–50 years old group.

Conclusion

This study suggested beneficial screening for women aged 31–50 years old. Instead of “original” nonavalent (HPV 16, 18, 6, 11, 31, 33, 45, 52, 58), the different “nonavalent” formula for HPV vaccines protecting against HPV 16, 18, 6, 11, 31, 39, 44, 52, 74 might be useful for Indonesian population. However, further multicenter studies with a huge sample size are still needed.

Prevalence and genotype distribution of high-risk human papillomavirus infection among women with cervical cytological abnormalities in Chongqing, China, 2014-2020

BACKGROUND

Persistent infection with high-risk human papillomavirus (HR-HPV) is the main leading cause of cervical precancerous lesions and cervical cancer. This study aims to explore the epidemiological characteristics of HR-HPV genotypes and their correlation with the ThinPrep cytological test (TCT) results among women in Chongqing, in China.

METHODS

In this retrospective study, cervical exfoliations of 14,548 women who visited Chongqing university cancer hospital were collected for detecting HR-HPV genotypes and TCT.

RESULTS

Overall, the rate of HR-HPV infection was 14.26%. The three most common HR-HPV genotypes are HPV52 (4.39%), HPV58 (2.21%), and HPV16 (1.94%). In this study, the positive rate of cervical TCT was 4.54%. Atypical squamous cells of undetermined significance (ASC-US), atypical squamous cells that could not exclude high-grade squamous intraepithelial lesion (ASU-H), low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), and atypical glandular cells of undetermined significance (AGC) were 2.99%, 0.20%, 0.92%, 0.29%, and 0.14%, respectively. Among the several types of cytological lesions, the HR-HPV infection rates of ASC-US, ASC-H, LSIL, HSIL, and (AGC) were 24.82%, 41.38%, 64.18%, 95.24%, and 23.81%, respectively.

CONCLUSIONS

HPV52, HPV 58, and HPV16 are the most common infection subtypes in Chongqing. When implementing HPV vaccine programs in Chongqing, HPV58 and HPV52 should be attached importance as HPV16 and HPV18.

Genetic characteristics of human papillomavirus type 16, 18, 52 and 58 in southern China

Persistent infections of high-risk human papillomaviruses (HPVs) are the leading cause of cervical cancers. We collected cervical exfoliated cell samples from females in Changsha city, Hunan Province and obtained 338 viral genomes of four major HPV types, including HPV 16 (n = 82), 18 (n = 35), 52 (n = 121) and 58 (n = 100). The lineage/sublineage distribution of the four HPVs confirmed previous epidemiological reports, with the predominant prevailing sublineage as A4 (50%), A1 (37%) and A3 (13%) for HPV16, A1 (83%) for HPV18, B2 (86%) for HPV52 and A1 (65%), A3 (19%) and A2 (12%) for HPV58. We also identified two potentially novel HPV18 sublineages, i.e. A6 and A7. Virus mutation analysis further revealed the presence of HPV16 and HPV58 sublineages associated with potentially high oncogenicity. These findings expanded our knowledge of the HPV genetic diversity in China, providing valuable evidence to facilitate HPV DNA screening, vaccine effectiveness evaluation and control strategy development.

Prevalence and genotype distribution of human papillomavirus infection in Huzhou City, eastern China, 2018-2019

BACKGROUND

Human papillomavirus (HPV) infection is involved in cervical cancer development, and hence understanding its prevalence and genotype distribution is important. However, there are few reports on the prevalence and genotype distribution of HPV in the city of Huzhou in China.

METHODS

In this retrospective cross-sectional study, 11,506 women who visited Huzhou Maternity & Child Health Care Hospital between January 2018 and October 2019 were enrolled. The results of HPV genotyping and cytology tests were analyzed.

RESULTS

The overall prevalence of HPV infection was 15.5%. The rate of high-risk (HR) HPV infection (13.5%) was higher than that of single low-risk (LR) HPV infection (2.0%) (p<0.05). The five most common HPV genotypes were HPV52 (3.3%), 16 (1.9%), 58 (1.7%), 53 (1.5%), and 81 (1.2%). The infection rate of HPV peaked in women aged 16-24 and women aged ≥55. The infection rate of HPV58 or HPV81 appeared as a single peak in women aged ≥55. The rates of HR-HPV and LR-HPV infection were higher in subjects with abnormal cytology (p<0.05).

CONCLUSIONS

HPV infection is high in Huzhou, and HPV53 and HPV81 are the prevalent genotypes. HPV infection rate is associated with age and cytology. Regional HPV surveillance is essential to optimize current HPV prevention and vaccine development.

The prevalence of HR-HPV infection based on self-sampling among women in China exhibited some unique epidemiologic features

Objective To investigate the epidemiological characteristics of high-risk human papillomavirus(HR-HPV) infection based on vaginal self-collected samples. Study Design and Setting The pooled data of 3045 self-collected samples used for the analysis derived from four previous studies on cervical cancer screening(The Chinese Multi-Center Screening Trial, CHIMUST; The Shenzhen Cervical Cancer Screening Trial-2, SHENCCAST-2; The Chinese Cervical Cancer Prevention Study, CHIPCAPS; Pingshan trial, PINGSHAN)conducted across China by our team since 2011. These cases were evaluated for HR-HPV type prevalence relative to lesion grade and age. The occurrence of cervical intraepithelial neoplasia(CIN) with specific HPV types and the influence of co-infection is explored. Results The top three most common genotypes among the HR-HPV positives were HPV-52(23.4%), HPV-16(18.0%), and HPV-58(15.50%). For women with CIN2+, the most frequent genotypes were HPV-16, 58, 52, and 18 in sequence. HPV-16 accounted for the majority of CIN2/CIN3/Ca with attribution rate of 23.86%, 44.78% and 50.00% respectively. HPV-58 accounted for 19.48%, 16.79% and 13.46% respectively. CIN2+ was found in the following types most frequently: HPV-16(31.23%), HPV-33(24.03%), HPV-58(18.41%), HPV-31(11.76%), HPV-18(7.75%), and HPV-52(7.30%). HPV-16 showed preference for co-infection with HPV-52 and HPV-58. Conclusion The prevalence of HR-HPV infection based on self-sampling among women in China exhibited some unique epidemiologic features.

Current Updates on Cancer-Causing Types of Human Papillomaviruses (HPVs) in East, Southeast, and South Asia

Simple Summary

Among the over 200 human papillomavirus (HPV) genotypes identified, approximately 15 of them can cause human cancers. In this review, we provided an updated overview of the distribution of cancer-causing HPV genotypes by countries in East, Southeast and South Asia. Besides the standard screening and treatment methods employed in these regions, we unravel HPV detection methods and therapeutics utilised in certain countries that differ from other part of the world. The discrepancies may be partly due to health infrastructure, socio-economy and cultural diversities. Additionally, we highlighted the area lack of study, particularly on the oncogenicity of HPV genotype variants of high prevalence in these regions.

Abstract

Human papillomavirus (HPV) infection remains one of the most prominent cancer-causing DNA viruses, contributing to approximately 5% of human cancers. While association between HPV and cervical cancers has been well-established, evidence on the attribution of head and neck cancers (HNC) to HPV have been increasing in recent years. Among the cancer-causing HPV genotypes, HPV16 and 18 remain the major contributors to cancers across the globe. Nonetheless, the distribution of HPV genotypes in ethnically, geographically, and socio-economically diverse East, Southeast, and South Asia may differ from other parts of the world. In this review, we garner and provide updated insight into various aspects of HPV reported in recent years (2015–2021) in these regions. We included: (i) the HPV genotypes detected in normal cancers of the uterine cervix and head and neck, as well as the distribution of the HPV genotypes by geography and age groups; (ii) the laboratory diagnostic methods and treatment regimens used within these regions; and (iii) the oncogenic properties of HPV prototypes and their variants contributing to carcinogenesis. More importantly, we also unveil the similarities and discrepancies between these aspects, the areas lacking study, and the challenges faced in HPV studies.

Prevalence and genotype distribution of high-risk HPV infection among women in Beijing, China

Cervical cancer (CC) is highly associated with high-risk human papillomavirus (HPV) infection and genotype distribution of high-risk HPV (HR-HPV) infection varies greatly in different regions. Clinical specimens were collected from 46 365 patients at Beijing Friendship Hospital, Capital Medical University from January 2017 to December 2020. HPV DNA genotype testing was performed using real-time PCR. The infection rates based on disease group were compared using the χ ² test. The linear-by-linear association test and gamma value were used to assess the changes in HPV prevalence over calendar year and age group. A total of 10 514 women were infected with HR-HPV, with an overall positive rate of 22.7%. The most prevalent HR-HPV types were HPV52, 58, 16, 51, and 66, and HPV59 had a higher prevalence except for HPV16, 58, and 52 in the CC group. Single infection of HR-HPV was dominant among different disease groups. The infection rate of HR-HPV decreased first and then increased from below 20 years old to over 60 years old. There were significant differences in the HR-HPV infection rates among the age and disease groups. Our findings demonstrate that the genotype distribution of HR-HPV varied with age and diseases. The HR-HPV genotypes prevalence was found to be directly useful for local governments to promote HPV targeted vaccination in the study region.

The genetic variability, phylogeny and functional significance of E6, E7 and LCR in human papillomavirus type 52 isolates in Sichuan, China

Background

Variations in human papillomavirus (HPV) E6 and E7 have been shown to be closely related to the persistence of the virus and the occurrence and development of cervical cancer. Long control region (LCR) of HPV has been shown multiple functions on regulating viral transcription. In recent years, there have been reports on E6/E7/LCR of HPV-16 and HPV-58, but there are few studies on HPV-52, especially for LCR. In this study, we focused on gene polymorphism of the HPV-52 E6/E7/LCR sequences, assessed the effects of variations on the immune recognition of viral E6 and E7 antigens, predicted the effect of LCR variations on transcription factor binding sites and provided more basic date for further study of E6/E7/LCR in Chengdu, China.

Methods

LCR/E6/E7 of the HPV-52 were amplified and sequenced to do polymorphic and phylogenetic analysis. Sequences were aligned with the reference sequence by MEGA 7.0 to identify SNP. A neighbor-joining phylogenetic tree was constructed by MEGA 7.0, followed by the secondary structure prediction of the related proteins using PSIPRED 4.0. The selection pressure of E6 and E7 coding regions were estimated by Bayes empirical Bayes analysis of PAML 4.9. The HLA class-I and II binding peptides were predicted by the Immune Epitope Database server. The B cell epitopes were predicted by ABCpred server. Transcription factor binding sites in LCR were predicted by JASPAR database.

Results

50 SNP sites (6 in E6, 10 in E7, 34 in LCR) were found. From the most variable to the least variable, the nucleotide variations were LCR > E7 > E6. Two deletions were found between the nucleotide sites 7387–7391 (TTATG) and 7698–7700 (CTT) in all samples. A deletion was found between the nucleotide sites 7287–7288 (TG) in 97.56% (40/41) of the samples. The combinations of all the SNP sites and deletions resulted in 12 unique sequences. As shown in the neighbor-joining phylogenetic tree, except for one belonging to sub-lineage C2, others sequences clustered into sub-lineage B2. No positive selection was observed in E6 and E7. 8 non-synonymous amino acid substitutions (including E3Q and K93R in the E6, and T37I, S52D, Y59D, H61Y, D64N and L99R in the E7) were potential affecting multiple putative epitopes for both CD4+ and CD8+ T-cells and B-cells. A7168G was the most variable site (100%) and the binding sites for transcription factor VAX1 in LCR. In addition, the prediction results showed that LCR had the high probability binding sites for transcription factors SOX9, FOS, RAX, HOXA5, VAX1 and SRY.

Conclusion

This study provides basic data for understanding the relation among E6/E7/LCR mutations, lineages and carcinogenesis. Furthermore, it provides an insight into the intrinsic geographical relatedness and biological differences of the HPV-52 variants, and contributes to further research on the HPV-52 therapeutic vaccine development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01565-5.

Understanding the impact of high-risk human papillomavirus on oropharyngeal squamous cell carcinomas in Taiwan: A retrospective cohort study

BACKGROUND AND OBJECTIVES

Human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma (OPSCC) is increasing globally. In Taiwan, HPV-positive OPSCC is obscured by tobacco, alcohol, and betel quid use. We investigated the role of high-risk HPV (hrHPV) in a large retrospective Taiwan OPSCC cohort.

METHODS AND RESULTS

The cohort of 541 OPSCCs treated at Chang Gung Memorial Hospital from 1998-2016 consisted of 507 men (94%) and 34 women (6%). Most used tobacco (81%), alcohol (51%), and betel quid (65%). Formalin-fixed, paraffin-embedded tissue was used for p16 staining (a surrogate marker for HPV) and testing for HPV DNA presence and type by Multiplex HPV PCR-MassArray. HPV DNA and/or p16 staining (HPV-positive) was found in 28.4% (150/528) tumors. p16 and HPV DNA were strongly correlated (F < 0.0001). HPV16 was present in 82.8%, and HPV58 in 7.5% of HPV-positive tumors. HPV was associated with higher age (55.5 vs. 52.7 years, p = 0.004), lower T-stage (p = 0.008) better overall survival (OS) (hazard ratio [HR] 0.58 [95% CI 0.42-0.81], p = 0.001), and disease-free survival (DFS) (HR 0.54 [95% CI 0.40-0.73], p < 0.0001). Alcohol was strongly associated with recurrence and death (OS: HR 2.06 [95% CI 1.54-2.74], p < 0.0001; DFS: HR 1.72 [95% CI 1.33-2.24], p < 0.0001). OS and DFS in HPV-positive cases decreased for alcohol users (p < 0.0001). Obscured by the strong alcohol effect, predictive associations were not found for tobacco or betel quid.

CONCLUSIONS

As with HPV-positive OPSCC globally, HPV is an increasingly important etiological factor in Taiwanese OPSCC. HPV-positive OPSCC has considerable survival benefit, but this is reduced by alcohol, tobacco, and betel quid use. hrHPV is a cancer risk factor in males and females. Vaccinating both sexes with a multivalent vaccine including HPV58, combined with alcohol and tobacco cessation policies will be effective cancer-prevention public health strategies in Taiwan.

The prevalence and distribution of human papillomavirus among 10,867 Chinese Han women

Objective

To assess the prevalence and distribution of HPV genotypes among Chinese Han women, and to explore the risk of high-grade cervical lesions associated with individual hr-HPV genotypes.

Methods

Genotyping and histopathology data from the Chinese Multi-Center Screening Trial (CHIMUST) and its pilot screening trial, from 6 regions across mainland China, were re-analyzed. The data from physician- and self-collected samples from 10,867 Chinese Han women (ages 30–69) were used to determine the prevalence and distribution of hr-HPV and to explore the risk association between hr-HPV genotypes and precancerous lesions.

Results

9.2% of the study population tested hr-HPV positive in physician-collected sample. The prevalence varied regionally from the lowest in Guangdong (6.3%) to the highest in Inner Mongolia (13.0%). The most prevalent genotypes found were HPV-52 (21.7%), HPV-16 (19.2%), HPV-58 (15.0%), HPV-39 (8.9%), and HPV-51 (8.2%). The overall odds ratios for CIN2+ and CIN3+ for the presence of HPV-16 was 58.6 (95% CI 39.2–87.5) and, 91.6 (95%CI 54.3–154.6), respectively and remained the highest odds ratio for CIN3+ in all 6 regions.

Conclusion

Geographical variation exists in the prevalence and distribution of hr-HPV in mainland China. HPV-16/52/58 were the most prevalent genotypes, and HPV-16 had the highest risk for high-grade cervical lesions.

Trial registration

CHIMUST, Registration number: ChiCTR-EOC-16008456. Registered 11 May 2016.

Efficient combination of Human Papillomavirus Genotyping for the triage of women with Atypical Squamous Cells of Undetermined Significance in Chinese rural population: A population-based study

Objective: In this prospective, population-based study, we evaluated the utility of high-risk human papillomavirus (HR-HPV) genotyping for triaging women with atypical squamous cells of undetermined significance (ASC-US) in the Chinese rural area. Methods: A total of 40,000 women were recruited from rural areas of Shanxi Province, China, between June 2014 and December 2014. Women with Pap results of ASC-US underwent HPV genotyping, colposcopy and histopathological examination. For those with normal cervixes or cervical intraepithelial neoplasia (CIN) 1 on the initial evaluation, a 2-year follow-up study was performed. Results: The reporting rate of ASC-US was 5.76% (2,304/40,000) in the study population. The detection rates of CIN 2 or above (CIN2+) and CIN 3 or above (CIN3+) in women with ASC-US were 7.28% and 1.75%, respectively. HPV 16 (39.53%), HPV 58 (17.83%), and HPV 52 (15.50%) were the three most prevalent HR-HPV genotypes among all women with ASC-US cytology. The five most common HR-HPV genotypes in CIN3+ lesions were HPV16, HPV58, HPV33, HPV31 and HPV18. Compared with the 15 HR-HPV testing, genotyping for a combination of HPV16/18/31/33/58 increased specificity significantly with virtually no loss of sensitivity for detecting CIN2+ and CIN3+ lesions, as well as significantly reduced colposcopy referral rate (23.15% vs 33.70%, p<0.01). In addition, in the 2-year follow-up period, women with infection of HPV16, 18, 31, 33 or 58 genotypes were the most likely population (92%, 23/25) to develop CIN2 lesion. Conclusion: Our results demonstrate that genotyping for a combination of HPV16/18/31/33/58 provides a more efficient and cost-effective model to risk-stratify women with ASC-US in the Chinese rural population.

Prevalence and sociodemographic correlates of anogenital Human Papillomavirus (HPV) carriage in a cross-sectional, multi-ethnic, community-based Asian male population

Background

Addressing the burden of HPV-associated diseases among men is increasingly becoming a public health issue. The main objective of this study was to determine HPV prevalence among a healthy community-based Malaysian men.

Method

This was a cross-sectional study that recruited 503 healthy males from 3 community-based clinics in Selangor, Malaysia. Genital and anal samples were collected from each participant for 14 high risk and 2 low risk HPV DNA detection and genotyping. All participants responded to a set of detailed sociodemographic and sexual behaviour questionnaire.

Results

The median age at enrolment was 40 years old (IQR: 31–50). The anogenital HPV6/11 prevalence was 3.2% whereas high risk HPV prevalence was 27.1%. The genital HPV prevalence for HPV6/11 was 2.9% while high risk HPV was 18.8%. HPV6/11 prevalence in the anal canal was 1.6% and high risk HPV was 12.7%. HPV 18 was the most prevalent genotype detected in the anogenital area. There was a significant independent association between genital and anal HPV infections.

Conclusion

Anogenital HPV infection is common among Malaysian men. These findings emphasize the ubiquity of HPV infection and thus the value of population-wide access to HPV prevention.

Clinical analysis of HPV58-positive cervical cancer

Objective

To study the clinical features of HPV58-positive cervical cancer.

Methods

A retrospective analysis of 347 patients with HPV58- or HPV16 positive cervical cancer from the Department of Gynecology Tumor of Guangxi Medical University Affiliated Cancer Hospital was performed. Molecular hybridization was used to detect HPV genotypes. The clinical features, including age, pathology, and invasion, were compared between the HPV58 positive and HPV16 positive cervical cancer groups.

Results

A total of 347 patients were eligible for this study, and the proportion of patients who were with poorly differentiated cancer (P = 0.015) was significantly higher in the HPV58 positive group. HPV58 positivity was an independent risk factor for poorly differentiated cancer [HR 2.156, 95% confidence interval: 1.167–3.984, P = 0.014]. The percentage of uterus corps invasion is significantly lower in HPV58 (p = 0.041), but HPV58 positivity is the independent risk factor for uterus corps invasion [HR = 3.985, 95% confidence interval: 1.066–14.893, P = 0.040]. The overall survival of HPV58-positive cervical cancer patients with uterine corpus invasion was significantly lower (P = 0.000). The age of patients in the HPV58-positive cervical cancer at advanced stage was significantly older (P = 0.045).

Conclusions

HPV58-positive cervical cancer patients are at higher risk of poorly differentiated cancer and uterus corps invasion. The patients with HPV58 positive cervical cancer with uterus corps invasion may result a worse prognosis.

Chlamydia trachomatis and Human Papillomavirus Infection in Women From Southern Hunan Province in China: A Large Observational Study

Chlamydia trachomatis and human papillomavirus (HPV) are the most common pathogens of sexually transmitted infections (STIs), which can increase the risk of cervical cancer and infertility. The purpose of this study was to evaluate the prevalence, genotype and risk factors of C. trachomatis and/or HPV infection in women attending the annual physical examination, assistant reproductive treatment and visiting the gynecology clinics from Southern Hunan province in China. Cervical-swab samples were collected from 5006 participants. We found that the overall prevalence of C. trachomatis, HPV infection and C. trachomatis/HPV coinfection was 4.7% (236/5006), 15.5% (778/5006) and 1.2% (59/5006), while the prevalence of asymptomatic infection of that was 3.8% (38/1006), 10.8% (109/1006) and 0.6% (6/1006), respectively. Furthermore, 25.0% (59/236) of C. trachomatis infection and 7.6% (59/778) of HPV infection were attributable to C. trachomatis and HPV coinfection. C. trachomatis and HPV infection were more often observed in young women of less than 25 years (10.4% and 21.3%, respectively) and in the outpatients from gynecology clinics (5.2% and 18.0%, respectively). Of note, a higher prevalence of C. trachomatis infection was observed in HPV-positive women (7.6%) than HPV- negative ones (4.2%), and vice versa. The top three C. trachomatis genotypes were E (1.4%), F (1.1%) and J (0.8%), and the counterparts of HPV genotypes were HPV52 (4.2%), HPV16 (2.3%) and HPV58 (2.2%), respectively. Among the 151 outpatients with colposcopy data, HPV infection was associated with severe cervical lesions with OR of 15.86 (95% CI 3.14–80.0, P < 0.001) while C. trachomatis infection was more likely associated with a low grade colposcopy impression (OR = 3.25, 95% CI: 1.22–8.65, P = 0.018). Our data highlight the high prevalence of asymptomatic C. trachomatis and HPV infection, particularly among women of <25 years. The two pathogens may serve as mutual risk factors to increase the risk of infections and cervical lesions. Widespread implementation of HPV and C. trachomatis screening programs, especially for young women, would be an effective strategy to relieve the burden of sexually transmitted infections.

Multi-Infection Patterns and Co-infection Preference of 27 Human Papillomavirus Types Among 137,943 Gynecological Outpatients Across China

Background: The epidemiological feature of human papillomavirus (HPV) infection is distinctive in China. We aimed to investigate the multi-infection patterns and co-infection preference of 27 HPV types among gynecological outpatients across China.

Methods: Overall 137,943 gynecological outpatients were recruited from eight tertiary hospitals located in seven regions of China, between July 1st, 2014 and December 31st, 2016. The overall, region-specific, age-specific and type-specific prevalence of HPV infection were calculated, respectively. The pattern of HPV infection was also evaluated. Furthermore, rate ratio was calculated to evaluate the co-infection preference of any two HPV genotypes.

Results: The overall prevalence of 27 HPVs' [17 high-risk (hr)/10 low-risk (lr)] infection was 23.5%. The age-specific HPV prevalence showed a “U-shaped” pattern. The most prevalent hrHPV genotypes were 16, 52, and 58. Multiple infections were detected in 25.8% of the HPV-positive women, in which dual infection was more prevalent. HPV 16/18 were likely to co-infected with HPV 31 but unlikely with HPV 52/58, i.e., the co-infection of HPV 16 with HPV 31 was high (3.5-fold), but low for HPV 58 (1.8-fold), and 52 (1.2-fold), while the co-infection of HPV 18 with HPV 31 was high (4.3-fold), but low for HPV 52 (1.9-fold), and 58 (1.7-fold).

Conclusions: We found age-specific prevalence of HPV infection showed a “U-shaped” pattern for high and low risk HPV, suggesting the importance of screening among younger women and the necessary of detection among older women. We found a novel co-infection preference of HPV 16/18 with 31, 52, and 58, suggesting a need of developing and marketing prophylactic HPV vaccines that protect against more genotypes in China.

Human Papillomavirus 58 E7 T20I/G63S Variant Isolated from an East Asian Population Possesses High Oncogenicity

Human papillomavirus (HPV) type 58 is the third most commonly detected HPV type in cervical cancer among Eastern Asians. Our previous international epidemiological studies revealed that HPV58 carrying an E7 natural variant, T20I/G63S (designated V1), was associated with a higher risk of cervical cancer. We recently showed that V1 possesses a greater ability to immortalize and transform primary cells, as well as degrading pRB more effectively, than the prototype and other common variants. In this study, we performed a series of phenotypic and molecular assays using physiologically relevant in vitro and in vivo models to compare the oncogenicity of V1 with that of the prototype and other common natural variants. Through activation of the AKT and K-Ras/extracellular signal-regulated kinase (ERK) signaling pathways, V1 consistently showed greater oncogenicity than the prototype and other variants, as demonstrated by increased cell proliferation, migration, and invasion, as well as induction of larger tumors in athymic nude mice. This study complements our previous epidemiological and molecular observations pinpointing the higher oncogenicity of V1 than that of the prototype and all other common variants. Since V1 is more commonly found in eastern Asia, our report provides insight into the design of HPV screening assays and selection of components for HPV vaccines in this region.IMPORTANCE Epidemiological studies have revealed that a wild-type variant of HPV58 carrying an E7 variation, T20I/G63S (V1), is associated with a higher risk of cervical cancer. We previously reported that this increased oncogenicity could be the result of the virus's greater ability to degrade pRB, thereby leading to an increased ability to grow in an anchorage-independent manner. In addition to this, this report further showed that this HPV variant induced activation of the AKT and K-Ras/ERK signaling pathways, thereby explaining its genuine oncogenicity in promoting cell proliferation, migration, invasion, and formation of tumors, all to a greater extent than the prototype HPV58 and other common variants.

Evaluation of alternately combining HPV viral load and 16/18 genotyping in secondary screening algorithms

Background

Correlation with HPV viral load and worsening cervical lesions had been reported, but its potential for triage after primary HPV screening has not been adequately explored, especially when combined with HPV-16/18 genotyping.

Objective

To evaluate combinations of human papillomavirus (HPV) viral load and genotyping for HPV-16/18 as secondary screening strategies.

Methods

The Shenzhen Cervical Cancer Screening Trial Ⅱ (SHENCCAST Ⅱ) database was re-analyzed to explore new screening algorithms using the results of Hybrid Capture 2 (HC2), Mass Array Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass spectrometry System (MALDI-TOF-MS) and the ThinPrep cytologic test (TCT) obtained by endocervical sampling.

Results

Compared with the recommended screening strategy of genotyping HPV-16/18 plus reflex to cytology, using viral load (10 RLU/CO as threshold) plus reflex to cytology resulted in less cytology but had a significantly higher sensitivity for cervical intraepithelial neoplasia 2+ (CIN2+)/CIN3+ without considerable changes in specificity and referral rates. Both of the strategy of using viral load ≥10 RLU/CO as cut-point for immediate colposcopy followed by triage genotyping HPV-16/18 for the other positive (≥1<10 RLU/CO) and the strategy of referring HPV-16/18 positives for immediate colposcopy followed by triage viral load (10 RLU/CO as threshold) for non-HPV-16/18 positives had comparable screening efficacy with algorithims that contain cytology.

Conclusions

Primary HPV screening with triage of HPV-positive women by a combination of viral load and genotyping for HPV-16/18 provides good balance between sensitivity and specificity, the number of tests required, and referral rates.

Screening for Human Papillomavirus in a Low- and Middle-Income Country

PURPOSE

Low- and middle-income countries have high incidences of cervical cancer linked to human papillomavirus (HPV), and without resources for cancer screenings these countries bear 85% of all cervical cancer cases. To address some of these needs, brigade-style screening combined with sensitive polymerase chain reaction–based HPV testing to detect common high-risk HPV genotypes may be necessary.

METHODS

We deployed an inexpensive DNA extraction technique and a real-time polymerase chain reaction–based HPV genotyping assay, as well as Papanicolaou testing, in a factory in San Pedro Sula, Honduras, where 1,732 women were screened for cervical cancer.

RESULTS

We found that 28% of participants were positive for high-risk HPV, with 26% of HPV-positive participants having more than one HPV infection. Moreover, the most common HPV genotypes detected were different than those routinely found in the United States.

CONCLUSION

This work demonstrates a deployable protocol for HPV screening in low- and middle-income countries with limited resources to perform cytopathology assessment of Pap smears.

Towards Understanding of Polymorphism of the G-rich Region of Human Papillomavirus Type 52

The potential to affect gene expression via G-quadruplex stabilization has been extended to all domains of life, including viruses. Here, we investigate the polymorphism and structures of G-quadruplexes of the human papillomavirus type 52 with UV, CD and NMR spectroscopy and gel electrophoresis. We show that oligonucleotide with five G-tracts folds into several structures and that naturally occurring single nucleotide polymorphisms (SNPs) have profound effects on the structural polymorphism in the context of G-quadruplex forming propensity, conformational heterogeneity and folding stability. With help of SNP analysis, we were able to select one of the predominant forms, formed by G-rich sequence d(G₃TAG₃CAG₄ACACAG₃T). This oligonucleotide termed HPV52_(1-4) adopts a three G-quartet snap back (3 + 1) type scaffold with four syn guanine residues, two edgewise loops spanning the same groove, a no-residue V loop and a propeller type loop. The first guanine residue is incorporated in the central G-quartet and all four-guanine residues from G4 stretch are included in the three quartet G-quadruplex core. Modification studies identified several structural elements that are important for stabilization of the described G-quadruplex fold. Our results expand set of G-rich targets in viral genomes and address the fundamental questions regarding folding of G-rich sequences.

Oncogenicitiy Comparison of Human Papillomavirus Type 52 E6 Variants

Human papillomavirus (HPV) infection contributes to virtually all cases of cervical cancer, the fourth most common cancer affecting women worldwide. The oncogenicity of HPV is mainly attributable to the E6 and E7 oncoproteins. HPV-52 is the seventh most common HPV type globally, but it has a remarkably high prevalence in East Asia. In previous studies it has been speculated that the oncogenicity might vary among different HPV-52 variants. In the present study, we compared the oncogenicity of E6 derived from the HPV-52 prototype and three commonly found variants, V1 (K93R), V2 (E14D/V92L) and V3 (K93R/N122K), through molecular and phenotypic approaches. We demonstrated that cells containing V1 achieved higher colony formation and showed greater cell migration ability when compared to other variants, but no difference in cell immortalization ability was observed. At the molecular level, the three variants formed complexes with E6-associated protein (E6AP) and p53 as efficiently as the prototype. They degraded p53 and PSD95/Dlg/ZO-1(PDZ) proteins, including MAGI-1c and Dlg, to a similar extent. They also exhibited a similar subcellular localization, and shared a half-life of approximately 45 min. Our findings provide a clearer picture of HPV-52 E6 variant oncogenicity, which is important for further studies aiming to understand the unusually high prevalence of HPV-52 among cervical cancers in East Asia.

HPV prevalence and genotype distribution among women in Shandong Province, China: Analysis of 94,489 HPV genotyping results from Shandong's largest independent pathology laboratory

Background

Data regarding human papillomavirus (HPV) prevalence and genotype distribution are limited in Shandong Province, China. Therefore, we investigated the recent HPV prevalence and genotype distribution among females in Shandong and aimed to provide comprehensive data to guide HPV-based cervical cancer screening and HPV vaccination for this population of Chinese women.

Methods

HPV testing results of 94,489 females were retrospectively reviewed and extracted from the database of Jinan KingMed Diagnostics, the largest independent pathology laboratory in Shandong Province, China. HPV was detected by a HPV genotyping panel from January 2011 to June 2017. The overall prevalence, age-specific prevalence, and genotype distribution were analyzed.

Results

A total of 26,839 cases (28.4%) were HPV-positive, with 4.3% positive for low- or undetermined-risk HPV (lr-/urHPV)-only, 18.1% positive for high-risk HPV (hrHPV)-only, and 6.1% positive for mixed lr-/urHPV and hrHPV infections. Single HPV infections accounted for 62.8%, while the rest were multiple HPV infections of two or more genotypes. HPV16 (5.8%), HPV52 (5.1%), HPV58 (3.5%), HPV51 (2.6%), and HPV56 (2.3%) were the five most common hrHPV genotypes; while HPV81 (2.8%), HPV53 (2.8%), and HPV6 (2.3%) were the three most common lr-/urHPV genotypes. HPV18 (1.7%) was only the ninth most common hrHPV genotype. HPV16 but not HPV52 was more common in single infections than in multiple infections. The distribution of both mixed lr-/urHPV and hrHPV as well as overall HPV infections demonstrated a bimodal pattern across age groups, of which the first peak appeared in the younger group and the second peak was found in older women. A similar age-specific distribution was observed in multiple infections of three or more subtypes as well. Moreover, the proportion of mixed lr-/urHPV and hrHPV infection significantly increased, while those of lr-/urHPV-only and hrHPV-only infections declined as the number of co-infections increased during the study period.

Conclusion

This large daily clinical practice report shows that HPV prevalence and genotype distribution are different in this population, who had limited cervical cancer screening service, compared to those in developed countries. Therefore, different strategies should be developed for HPV-based cervical cancer screening and vaccine-based HPV prevention in Shandong Province.

Oncogenic comparison of human papillomavirus type 58 E7 variants

Human papillomavirus 58 (HPV58) ranks the second or third in East Asian cervical cancers. Current studies on HPV58 are scarce and focus on the prototype. Previously, we identified the three most common circulating HPV58 E7 strains contained amino acid alterations: G41R/G63D (51%), T20I/G63S (22%) and T74A/D76E (14%) respectively. Among them, the T20I/G63S variant (V1) had a stronger epidemiological association with cervical cancer. We therefore suggested that V1 possessed stronger oncogenicity than the other two variants. Here, we performed phenotypic assays to characterize and compare their oncogenicities with HPV58 E7 prototype. Our results showed that overexpression of V1 conferred a higher colony-forming ability to primary murine epithelial cells than prototype (P < 0.05) and other variants, implicating its higher immortalising potential. Further experiments showed that both V1 and prototype enhanced the anchorage-independent growth of NIH/3T3 cells (P < 0.001), implicating their stronger transforming power than the two other variants. Moreover, they possessed an increased ability to degrade pRb (P < 0.001), which is a major effector pathway of E7-driven oncogenesis. Our work represents the first study to compare the oncogenicities of HPV58 E7 prototype and variants. These findings deepened our understanding of HPV58 and might inform clinical screening and follow-up strategy.

Distinct geographic clustering of oncogenic human papillomaviruses multiple infections in cervical cancers: Results from a worldwide cross-sectional study

Coinfections by multiple Human Papillomaviruses (HPVs) are observed in approximately 6-8% of invasive cervical cancer (ICC) cases worldwide. But neither the presence of persistent HPVs coinfections nor their etiological role in the development of ICC is well understood. Cervical HPVs coinfections have been observed randomly, mostly in women with preneoplastic lesions, and only few studies have globally analyzed ICC cases. Here we explored the HPVs multiple infection patterns in a large worldwide sample of cross-sectional ICC cases. Paraffin-embedded ICC biopsy samples were tested using stringent HPV genotyping. Logistic regression models were used to identify the most likely pairwise HPV types in multiple infections. Multivariate analysis was applied to detect significant HPV coinfection patterns beyond pairwise HPVs comparison. Among 8780 HPV DNA-positive ICC cases worldwide, 6.7% (N = 587) contained multiple HPVs. Pairwise analysis revealed that HPV16|74, HPV31|33, HPV31|44, HPV33|44 and HPV45|70 pairs were significantly more frequently found together in multiple infections compared to any other HPV type combination, which supports the occasional role of Alpha-10 LR-HPVs in cervical cancers. In contrast, HPV16|31, HPV16|45, HPV16|51 and HPV18|HPV45 pairs were significantly less frequently found together than with any other HPV pair combination. Multivariate analysis sustained the results and revealed for the first time a distinct coinfection pattern in African ICCs stemming from the clustering of oncogenic HPV51/35/18/52 coinfections in African women. We suggest that the differential geographic HPVs coinfections clustering observed might be compatible with a specific modulation of the natural history/oncogenic potential of particular HPVs multiple infections and warrant monitoring for post-vaccinated.

Prevalence of human papillomavirus among Wenzhou women diagnosed with cervical intraepithelial neoplasia and cervical cancer

Background

Human papillomavirus (HPV) is associated with an increased risk of cervical cancer. Using a vaccine to prevent HPV infections could be a cost-effective strategy to decrease the incidence of cervical cancer. Learning about the characteristics of CIN patients with HPV infection in Wenzhou is a key step in guiding the use of HPV vaccines and screening for cervical cancer.

Methods

We undertook a retrospective analysis including 2612 women who were treated in the Department of Gynecology and Obstetrics from Jan 2016 to Nov 2017. All of the patients were examined by HPV testing and histology.

Results

The prevalence of HR-HPV among women with cervical intraepithelial lesions aged 65-69 years (38.8%) was significantly higher than that of the other age groups. The percentage of patients diagnosed with HPV-positive HSIL progressively increased with age to a maximum of 18.0% in the group of 40 to 44 years of age. HPV 16, 52, and 58 were the three most dominant genotypes among these women, and single infections (950, 73.3%) were more common than multiple infections (346, 26.7%). Compared to cervicitis, the odds ratios (ORs) for LSIL associated with HPV 33, 52, 16 and HPV 58 infection were 5.98, 3.91, 3.65, 3.65, and 3.188, respectively; for HSIL associated with HPV 16, 33, 58 and HPV 31 were 9.30, 7.68, 5.97, and 4.21, respectively. In LSIL, the frequencies of HR-HPV 52,16,58,18 were 19.3,18.2,10.9, and 7.8%, respectively.

Conclusion

Our study provides important data about the HPV genotype distribution and its correlation with cervical intraepithelial lesions in the Wenzhou population.

Genetic variability and oncogenic risk association of human papillomavirus type 58 E6 and E7 genes in Taizhou area, China

It is well recognized that the association of human papillomavirus (HPV) and cervical carcinogenesis is based on the presence of HPV DNA sequence. The E6 and E7 oncoproteins encoded by high-risk HPV types play a key role in carcinogenesis. HPV58 type accounts for a larger share of cervical disease in China, whereas data on HPV58 genetic variability in China is limited. We aimed to evaluate the diversity of HPV58 genetic variants by sequencing the entire E6 and E7 genes. Phylogenetic trees were constructed by Maximum likelihood method by MEGA 5.05 software. In this study, the overall HPV infection rate was 22.6% (2891/12780) in Southeast China and the prevalence of HPV58 infection rate was 2.6% (335/12780). 26 nucleotides substitutions were observed in E6 and E7 genes with 10 novel substitutions and 17 non-synonymous substitutions. We obtained 25 distinct variation patterns which the accession GenBank numbers as MH348918-MH348942. All of HPV58 variants belong to lineage A, while no lineage B, C and D were detected in Taizhou area, Southeast China. The sublineage A1, A2, and A3 variants were found in 136 (68.3%), 39 (19.6%), and 24 (12.1%) of HPV58 isolates, respectively. The sublineage A3 variants with T20I/G63S substitutions at E7 oncoprotein carried a significantly higher risk for high-grade cervical intraepithelial neoplasia (CIN2 or worse, CIN2+) when compared with other HPV58 variants (odds ratio = 4.41, P < 0.05). Nevertheless, there was no association between HPV58 (sub) lineages and cervical lesions. These data provide the critical characteristics of HPV58 variants to assist further investigation of carcinogenic association and the development of next generation vaccines and diagnostic assays in China.

Human papillomaviruses 16 and 58 are distributed widely among women living in Shanghai, China, with high-grade, squamous intraepithelial lesions

The distribution of human papillomaviruses (HPVs) must be understood for the control and prevention of cervical cancer. Community-based Papanicolaou and HPV DNA tests were performed on 41 578 women. The prevalences of HPV genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 were assessed. In total, 10% women were infected/co-infected by these HPVs. The infection rate increased from 7.1% in women aged ⩽30 years to 10.4% in those aged 50–60 years, and then decreased slightly to 9.9% in those aged >60 years. The HPV 16 and 58 positivity rates were significantly higher among women with high-grade squamous intraepithelial lesions (HSILs) than among those with cervicitis/negativity for intraepithelial lesion or malignancy (NILM) or low-grade SILs (LSILs). The HPV 18, 52 and 68 infection rates were significantly lower in women with HSILs than in those with NILM or LSILs. The proportion of women infected by multiple HPV strains was higher among those with HSILs. The proportions of the five most common genotypes, HPV 16, 18, 33, 52 and 58, increased with the number of co-infecting strains. HPV 16 and 58 were the high-risk HPVs in the Shanghai community and should be the focus in HPV screening and vaccination.

Prevalence and distribution of human papillomavirus genotypes in Chinese women between 1991 and 2016: A systematic review

BACKGROUND

Human papillomavirus (HPV) associated cervical cancer is one of the most common cancers and ranked as the eighth most common killer for Chinese women. A dozen of HPV vaccines are being developed in China without a solid China-specific distribution of carcinogenic HPV types, thus, we performed this systematic review to explore the China-specific spectrum of high-risk types causing cancer.

METHODS

Studies on HPV infection among Chinese women were searched. All retrieved articles were screened and reviewed by a standardized algorithm. Distribution of carcinogenic HPV types and age-specific prevalence were analyzed using random-effects model.

RESULTS

A total of 303 articles were included in the final analysis. The top 10 common HPV types detected in ICC patients, in descending order of frequency, were HPV 16 (62.5%), 18 (12.4%), 58 (8.6%), 52 (5.7%), 33 (4.6%), 31 (3.5%), 55 (2.4%), 68 (2.4%), 53 (2.2%) and 45 (2.0%) respectively. Similar spectrum was found in women with precancer. The prevalence of HPV infection peaked between 20 and 24 years with a rate of 24.3%, thereafter declined substantially and stabilized at middle-ages. Compared to women living in the developed provinces, the second peak was observed among women aged 45-55 years in less developed regions.

CONCLUSION

In general, the spectrum of HPV types in women with precancer/cancer and the pattern of age-specific prevalence were consistent with that of elsewhere worldwide. However, some distinguished characteristics could also be concluded, and these imprinting should be considered and integrated when developing vaccines and strategy for disease control in China.

Comparison of the digene hybrid capture 2 and Roche cobas 4800 HPV tests for detection of CIN2+ in a referral population in Japan

To examine validity of the hybrid capture-2 and cobas 4800 HPV tests, 396 women including 188 women visiting for cancer screening, and 208 referral cases were examined with both HPV tests and the liquid-based cervical Pap test. Concordant results between the HPV assays were observed in 333 cases (coincident rates; 84.1%, kappa value; 0.682). The sensitivity for CIN2+ was 98.6% (69/70) and 82.9% (58/70) for HC2 and cobas 4800 (McNemar's test; P = 0.0026). The sensitivity for CIN3+ was 97.2% (35/36) and 83.3% (30/36) (Not significant, P = 0.0736). The specificities for CIN2+ or CIN3+ did not differ between the tests. The HPV16, 52, 18, 31, and 58 were the most common types in CIN2+ cases. Reasonable sensitivity for HPV52, and cross-hybridization with some probable high-risk HPV type such as HPV82 explain the higher sensitivity of HC2 than cobas 4800 in detection of CIN2+ in a referral population in Japan.

Analysis of human papilloma virus type 52 integration status in exfoliated cervical cells

To explore the significance of human papilloma virus type 52 (HPV52) infection and its integration in cells within cervical lesions, the expression levels of HPV52 were detected using polymerase chain reaction (PCR). The copy numbers of HPV52 E2, HPV52 E6 and the reference gene β-actin were determined by quantitative PCR to analyze the association between HPV52 integration and cervical lesions. HPV52 integration was analyzed by the amplification of papillomavirus oncogene transcripts. A total of 13 samples from 468 cases were positive for HPV52. Among the samples, 1 case with an E2/E6 ratio >1 was purely episomal, 3 cases with an E2/E6 ratio of 0 were purely integrated, and 9 cases with an E2/E6 ratio of between 0 and 1 were a mixture of integrated and episomal. With the progression of cervical disease, the prevalence of the episomal type decreased gradually, and the prevalence of the integrated (episomal and integrated) forms increased. The pure integration of HPV52 occurred in chromosomes 2, 5 and 8. These results indicate that HPV52 integration into the host genome may be a key factor in cervical lesions. Thus, patients at high risk for cervical lesions may potentially be identified by screening for HPV52 infection and integration.

Prevalence and sociodemographic correlates of cervicovaginal human papillomavirus (HPV) carriage in a cross-sectional, multiethnic, community-based female Asian population

Objectives

Cervical cancer is a largely preventable disease, and the strategic implementation of a cervical cancer prevention programme is partly dependent on the impact of human papillomavirus (HPV) infection interpreted within the context of the country’s sociodemographic attributes. The objective of this study is to determine the prevalence of cervicovaginal HPV infection among a healthy, community-based, multiethnic Malaysian population. The HPV prevalence was subsequently correlated to the individual’s sociodemographics and sexual/reproductive history. Of significance, the observed prevalence captured was in a birth cohort not included in the national school-based HPV vaccination programme.

Methods

This was a cross-sectional study where 1293 healthy women aged between 18 and 60 years were recruited via convenience sampling from five community-based clinics in Selangor, Malaysia. Cervicovaginal self-samples were obtained and DNA was extracted for HPV detection and genotyping. A comprehensive questionnaire was administered to determine the sociodemographics and behavioural patterns of participants.

Results

The median age at enrolment was 37 years old (IQR: 30–47). In total, 86/1190 (7.2%) of the samples collected were positive for HPV infection, with the highest HPV prevalence (11.9%) detected in the subgroup of 18–24 years old. The top three most prevalent HPV genotypes were HPV 16, 52 and 58. The independent risk factors associated with higher rates of HPV infection included Indian ethnicity, widowed status and women with partners who are away from home for long periods and/or has another sexual partner.

Conclusions

The overall prevalence of HPV infection in this Malaysian multiethnic population was 7.2%, with 6.5% being high-risk genotypes. The top three most common high-risk HPV types were HPV 16, 52 and 58. This information is important for the planning of primary (HPV vaccination) and secondary (screening) cervical cancer prevention programmes in Malaysia.

Ancient Evolution and Dispersion of Human Papillomavirus 58 Variants

Human papillomavirus 58 (HPV58) is found in 10 to 18% of cervical cancers in East Asia but is rather uncommon elsewhere. The distribution and oncogenic potential of HPV58 variants appear to be heterogeneous, since the E7 T20I/G63S variant is more prevalent in East Asia and confers a 7- to 9-fold-higher risk of cervical precancer and cancer. However, the underlying genomic mechanisms that explain the geographic and carcinogenic diversity of HPV58 variants are still poorly understood. In this study, we used a combination of phylogenetic analyses and bioinformatics to investigate the deep evolutionary history of HPV58 complete genome variants. The initial splitting of HPV58 variants was estimated to occur 478,600 years ago (95% highest posterior density [HPD], 391,000 to 569,600 years ago). This divergence time is well within the era of speciation between Homo sapiens and Neanderthals/Denisovans and around three times longer than the modern Homo sapiens divergence times. The expansion of present-day variants in Eurasia could be the consequence of viral transmission from Neanderthals/Denisovans to non-African modern human populations through gene flow. A whole-genome sequence signature analysis identified 3 amino acid changes, 16 synonymous nucleotide changes, and a 12-bp insertion strongly associated with the E7 T20I/G63S variant that represents the A3 sublineage and carries higher carcinogenetic potential. Compared with the capsid proteins, the oncogenes E7 and E6 had increased substitution rates indicative of higher selection pressure. These data provide a comprehensive evolutionary history and genomic basis of HPV58 variants to assist further investigation of carcinogenic association and the development of diagnostic and therapeutic strategies.IMPORTANCE Papillomaviruses (PVs) are an ancient and heterogeneous group of double-stranded DNA viruses that preferentially infect the cutaneous and mucocutaneous epithelia of vertebrates. Persistent infection by specific oncogenic human papillomaviruses (HPVs), including HPV58, has been established as the primary cause of cervical cancer. In this work, we reveal the complex evolutionary history of HPV58 variants that explains the heterogeneity of oncogenic potential and geographic distribution. Our data suggest that HPV58 variants may have coevolved with archaic hominins and dispersed across the planet through host interbreeding and gene flow. Certain genes and codons of HPV58 variants representing higher carcinogenic potential and/or that are under positive selection may have important implications for viral host specificity, pathogenesis, and disease prevention.

Whole-genome analysis of human papillomavirus genotypes 52 and 58 isolated from Japanese women with cervical intraepithelial neoplasia and invasive cervical cancer

Background

Human papillomavirus genotypes 52 and 58 (HPV52/58) are frequently detected in patients with cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC) in East Asian countries including Japan. As with other HPV genotypes, HPV52/58 consist of multiple lineages of genetic variants harboring less than 10% differences between complete genome sequences of the same HPV genotype. However, site variations of nucleotide and amino acid sequences across the viral whole-genome have not been fully examined for HPV52/58. The aim of this study was to investigate genetic variations of HPV52/58 prevalent among Japanese women by analyzing the viral whole-genome sequences.

Methods

The entire genomic region of HPV52/58 was amplified by long-range PCR with total cellular DNA extracted from cervical exfoliated cells isolated from Japanese patients with CIN or ICC. The amplified DNA was subjected to next generation sequencing to determine the complete viral genome sequences. Phylogenetic analyses were performed with the whole-genome sequences to assign variant lineages/sublineages to the HPV52/58 isolates. The variability in amino acid sequences of viral proteins was assessed by calculating the Shannon entropy scores at individual amino acid positions of HPV proteins.

Results

Among 52 isolates of HPV52 (CIN1, n = 20; CIN2/3, n = 21; ICC, n = 11), 50 isolates belonged to lineage B (sublineage B2) and two isolates belonged to lineage A (sublineage A1). Among 48 isolates of HPV58 (CIN1, n = 21; CIN2/3, n = 19; ICC, n = 8), 47 isolates belonged to lineage A (sublineages A1/A2/A3) and one isolate belonged to lineage C. Single nucleotide polymorphisms specific for individual variant lineages were determined throughout the viral genome based on multiple sequence alignments of the Japanese HPV52/58 isolates and reference HPV52/58 genomes. Entropy analyses revealed that the E1 protein was relatively variable among the HPV52 isolates, whereas the E7, E4, and L2 proteins showed some variations among the HPV58 isolates.

Conclusions

Among the HPV52/58-positive specimens from Japanese women with CIN/ICC, the variant distributions were strongly biased toward lineage B for HPV52 and lineage A for HPV58 across histological categories. Different patterns of amino acid variations were observed in HPV52 and HPV58 across the viral whole-genome.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0155-4) contains supplementary material, which is available to authorized users.

Distribution and attribution of high-risk human papillomavirus genotypes in cervical precancerous lesions in China

While human papillomavirus vaccine was recently approved by China Food and Drug Administration, mapping of high-risk human papillomavirus distribution and attribution in cervical precancerous lesions in China becomes critical in development of a high-risk human papillomavirus-based cervical cancer screening and prevention strategy. In total, 1016 patients with cervical precancerous lesions diagnosed in the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences were analyzed retrospectively, including 111 patients with low-grade squamous intraepithelial lesions and 905 patients with high-grade squamous intraepithelial lesions. HPV16, 58, 52, 33, and 31 were the most common high-risk human papillomavirus genotypes in order of decreasing frequency among high-risk human papillomavirus-positive high-grade squamous intraepithelial lesions; this differed from the high-risk human papillomavirus distribution in low-grade squamous intraepithelial lesions (HPV16, 52, 39, 56, and 58). The distribution of high-risk human papillomavirus genotypes in single-type infections for high-grade squamous intraepithelial lesions (HPV16, 58, 33, and 52) was similar to that in multiple-type infections (HPV16, 58, 52, and 33). By contrast, a more diverse distribution spectrum of high-risk human papillomavirus genotypes for low-grade squamous intraepithelial lesions was observed between single-type (HPV16, 52, 39, and 56) and multiple-type infection (HPV52, 68, 58, 59, 39 and 56). A previously published method was adopted to calculate the fractional proportion of individual high-risk human papillomavirus genotypes in multiple infections. For this proportional attribution, HPV16 (48.9%), 58 (10.0%), 33 (5.5%), and 52 (5.5%) were the most frequent among all high-grade squamous intraepithelial lesions, whereas HPV16 (13.2%), 52 (11.6%), 39 (9.5%), and 56 (7.6%) were the most frequent among all low-grade squamous intraepithelial lesions. Differences in high-risk human papillomavirus distribution and proportional attribution in different cervical pathology statuses (high-grade squamous intraepithelial lesions and low-grade squamous intraepithelial lesions) demonstrated the critical role of persistent infection of certain high-risk human papillomavirus such as HPV16, 58, 33, and 52 in carcinogenesis of cervical cancer. Distinctively high prevalence of HPV58, 33 and 52 in Chinese cervical intraepithelial neoplasia population, especially in high-grade squamous intraepithelial lesions, should be taken into consideration in cervical cancer screening strategy and vaccine development.

Genotype distribution characteristics of multiple human papillomavirus in women from the Taihu River Basin, on the coast of eastern China

Background

There is limited data on the genotype distribution of human papillomavirus (HPV) in the Taihu River Basin, home to 1.29 million people on the coast of eastern China. This study evaluated the prevalence and genotypes among different female age groups in this region.

Methods

Twenty-six HPV strains (low-risk HPV 6, 11, 40, 42, 44, 61, 73 and high-risk HPV 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 55, 56, 58, 59, 66, 68, 82, and 83) were detected using Tellgenplex™ HPV technology in samples obtained from three clinical hospitals located in different regions of the Taihu Lake Basin.

Results

The results showed that 1855 samples (20.97% of all samples) were found to be HPV-positive. Of these, 1375 samples (15.55% of all samples) were found to have a single HPV infection. Age-specific prevalence showed two peaks, one that corresponded to the group of 21–30 year-old women and the other peak that corresponded to the group of women over 51 years old. The three most prevalent genotypes were HPV52 (19.95%, 370/1855), HPV16 (13.48%, 150/1855), and HPV58 (11.32%, 210/1855). Mixed strains HPV58 + HPV33 and HPV58 + HPV52 were most commonly found in females infected with multiple HPV types.

Conclusions

This investigation reveals that HPV infection in the Taihu River Basin varied significantly among different age groups. The most prevalent genotypes are included in the nonavalent vaccine, V503, however this vaccine is not licensed for use in mainland China. The most frequently occurring genotypes should be considered in the development of next-generation HPV vaccines for optimal protection of public health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2328-6) contains supplementary material, which is available to authorized users.

Human papillomavirus infections among women with cervical lesions and cervical cancer in Eastern China: genotype-specific prevalence and attribution

Background

Cervical cancer and its precursor, high-grade cervical intraepithelial neoplasia (CIN2/3), are associated with persistent high-risk human papillomavirus (HPV) infection. HPV genotype prevalence varies with severity of cervical lesions, patient age and geographical location. The aim of this study was to investigate HPV genotypes prevalence and attribution according to the severity of cervical lesions among Chinese women.

Method

A 4-year surveillance study was performed. A total of 1664 female patients were included and their cervical histological diagnosis consisted of cervical intraepithelial neoplasia grade 1 (CIN1, 376 cases), grade 2 (CIN2, 408 cases), grade 3 (CIN3, 336 cases) and invasive cervical cancers (ICC, 544 cases). HPV genotypes prevalence and attribution to cervical lesions were calculated and analyzed. The 95% confidence interval (CI) for proportion was also calculated.

Results

HPV positivity rates increased directly with cervical lesions severity (72.4% for CIN1, 81.4% for CIN2, 88.1% for CIN3 and 90.4% for ICC). Infections with multiple HPV types were inversely related to cervical lesions severity. HPV16, 52, 31, 33 and 58 were the most prevalent genotypes in ICC. 49.1% of squamous cell carcinoma, 65.1% of adenocarcinoma and 12.0–43.3% of cervical intraepithelial neoplasia could be attributed to vaccine-covered high-risk genotypes (HPV16/18). Inclusion of HPV52 and HPV31 in future vaccines would provide the highest marginal benefit in protection for individuals residing in this region.

Conclusions

These findings provide information about HPV genotypes in this region which may be important to target with future vaccination and screening programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2223-1) contains supplementary material, which is available to authorized users.

Analysis of Sequence Variation and Risk Association of Human Papillomavirus 52 Variants Circulating in Korea

Introduction

Human papillomavirus (HPV) 52 is a carcinogenic, high-risk genotype frequently detected in cervical cancer cases from East Asia, including Korea.

Materials and Methods

Sequences of HPV52 detected in 91 cervical samples collected from women attending Seoul St. Mary’s Hospital were analyzed. HPV52 genomic sequences were obtained by polymerase chain reaction (PCR)-based sequencing and analyzed using Seq-Scape software, and phylogenetic trees were constructed using MEGA6 software.

Results

Of the 91 cervical samples, 40 were normal, 22 were low-grade lesions, 21 were high-grade lesions and 7 were squamous cell carcinomas. Four HPV52 variant lineages (A, B, C and D) were identified. Lineage B was the most frequently detected lineage, followed by lineage C. By analyzing the two most frequently detected lineages (B and C), we found that distinct variations existed in each lineage. We also found that a lineage B-specific mutation K93R (A379G) was associated with an increased risk of cervical neoplasia.

Conclusions

To our knowledge, we are the first to reveal the predominance of the HPV52 lineages, B and C, in Korea. We also found these lineages harbored distinct genetic alterations that may affect oncogenicity. Our findings increase our understanding on the heterogeneity of HPV52 variants, and may be useful for the development of new diagnostic assays and therapeutic vaccines.

The effect of single nucleotide polymorphisms in G-rich regions of high-risk human papillomaviruses on structural diversity of DNA

BACKGROUND

Infection with high-risk human papillomaviruses (HPVs) can lead to development of cancer of the head and neck and anogenital regions. G-rich sequences found in genomes of high-risk HPVs can fold into non-canonical secondary structures that could serve as 3D motifs distinct from double-stranded DNA and present recognition sites for ligands and opportunity for gene expression modulation.

METHODS

Combination of UV, CD and NMR spectroscopy and PAGE electrophoresis were used as they offer complementary insights into structural changes of G-rich oligonucleotides.

RESULTS

G-rich region of HPV16 is shown to preferentially form hairpin structures, while regions of HPV18, HPV52 and HPV58 fold into four-stranded DNA structures called G-quadruplexes. Single nucleotide polymorphisms found in G-rich sequences have been found to promote formation of hairpin structures of HPV16 and have affected number of species formed in G-rich region of HPV52, whereas they have exhibited minimal effect on the formation of HPV18 and HPV58 G-quadruplex structures. These structural changes were reflected in differences in apparent thermal stabilities.

CONCLUSIONS

Potential of G-rich sequences as drug targets was evaluated based on the results of the current study. HPV16 and HPV18 are considered less appropriate targets due to several single nucleotide polymorphisms and low stability, respectively. On the other hand, HPV52 and HPV58 could be used for small-molecule mediated stabilization.

GENERAL SIGNIFICANCE

G-rich sequences occurring in high-risk HPVs can fold into hairpin and G-quadruplex structures that could be potentially utilized as drug targets. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.

Meta-analysis of downregulated E-cadherin as a poor prognostic biomarker for cervical cancer

Aim: This meta-analysis was conducted to evaluate the diagnostic and prognostic functions of E-cadherin expression in cervical cancer. Methods: PubMed and other databases were searched for articles associated with E-cadherin and cervical cancer. These articles were published before June 2015 and written in English or Chinese. Random-effects model was used to pool odds ratios on the heterogeneity test in the meta-analysis. Results: All of 20 studies were analyzed, in which 522 (42.6%) subjects exhibited reduced E-cadherin expression. Evaluation of clinicopathologic features showed that the downregulation of E-cadherin was related to the overall survival, clinicopathological parameters and age. Conclusion: Downregulation of E-cadherin in cervical cancer patients showed poor overall survival. Therefore, E-cadherinmay be a metastasis-suppressor gene in cervical cancer.