Critical Residues Involved in the Coassembly of L1 and L2 Capsid Proteins of Human Papillomavirus 16.

Human papillomaviruses (HPV) are small DNA viruses associated with cervical cancer, warts, and other epithelial tumors. Structural studies have shown that the HPV capsid consists of 360 copies of the major capsid protein, L1, arranged as 72 pentamers in a T=7 icosahedral lattice, coassembling with substoichiometric amounts of the minor capsid protein, L2. However, the residues involved in the coassembly of L1 and L2 remain undefined due to the lack of structure information. Here, we investigated the solvent accessibility surfaces (SASs) of the central cavity residues of the HPV16 L1 pentamer in the crystal structure because those internal exposed residues might mediate the association with L2. Twenty residues in L1 protein were selected to be analyzed, with four residues in the lumen of the L1 pentamer identified as important: F256, R315, Q317, and T340. Mutations to these four residues reduced the PsV (pseudovirus) infection capacity in 293FT cells, and mutations to R315, Q317, and T340 substantially perturb L2 from coassembling into L1 capsid. Compared with wild-type (WT) PsVs, these mutant PsVs also have a reduced ability to become internalized into host cells. Finally, we identified a stretch of negatively charged residues on L2 (amino acids [aa] 337 to 340 [EEIE]), mutations to which completely abrogate L2 assembly into L1 capsid and subsequently impair the endocytosis and infectivity of HPV16 PsVs. These findings shed light on the elusive coassembly between HPV L1 and L2. IMPORTANCE Over 200 types of HPV have been isolated, with several high-risk types correlated with the occurrence of cervical cancer. The HPV major capsid protein, L1, assembles into a T=7 icosahedral viral shell, and associates with the minor capsid protein, L2, which plays a critical role in the HPV life cycle. Despite the important role of the L2 protein, its structure and coassembly with L1 remain elusive. In this study, we analyzed the amino acid residues at the proposed interface between L1 and L2. Certain mutations at these sites decreased the amount of L2 protein assembled into the capsid, which, in turn, led to a decrease in viral infectivity. Knowledge about these residues and the coassembly of L1 and L2 could help to expand our understanding of HPV biology and aid in the development of countermeasures against a wide range of HPV types by targeting the L2 protein.

CD161 expression and regulation defines rapidly responding effector CD4+ T cells associated with improved survival in HPV16-associated tumors.

BACKGROUND: Expression of killer cell lectin-like receptor B1 (KLRB1), the gene encoding the cell surface molecule CD161, is associated with favorable prognosis in many cancers. CD161 is expressed by several lymphocyte populations, but its role and regulation on tumor-specific CD4+ T cells is unknown. METHODS: We examined the clinical impact of CD4+CD161+ T cells in human papillomavirus (HPV)16+ oropharyngeal squamous cell carcinoma (OPSCC), analyzed their contribution in a cohort of therapeutically vaccinated patients and used HPV16-specific CD4+CD161+ tumor-infiltrating lymphocytes and T cell clones for in-depth mechanistic studies. RESULTS: Central and effector memory CD4+ T cells express CD161, but only CD4+CD161+ effector memory T cells (Tem) are associated with improved survival in OPSCC. Therapeutic vaccination activates and expands type 1 cytokine-producing CD4+CD161+ effector T cells. The expression of CD161 is dynamic and follows a pattern opposite of the checkpoint molecules PD1 and CD39. CD161 did not function as an immune checkpoint molecule as demonstrated using multiple experimental approaches using antibodies to block CD161 and gene editing to knockout CD161 expression. Single-cell transcriptomics revealed KLRB1 expression in many T cell clusters suggesting differences in their activation. Indeed, CD4+CD161+ effector cells specifically expressed the transcriptional transactivator SOX4, known to enhance T cell receptor (TCR) signaling via CD3ε. Consistent with this observation, CD4+CD161+ cells respond more vigorously to limiting amounts of cognate antigen in presence of interleukin (IL)-12 and IL-18 compared to their CD161- counterparts. The expression of CD161/KLRB1 and SOX4 was downregulated upon TCR stimulation and this effect was boosted by transforming growth factor (TGF)ß1. CONCLUSION: High levels of CD4+CD161+ Tem are associated with improved survival and our data show that CD161 is dynamically regulated by cell intrinsic and extrinsic factors. CD161 expressing CD4+ T cells rapidly respond to suboptimal antigen stimulation suggesting that CD161, similar to SOX4, is involved in the amplification of TCR signals in CD4+ T cells.

Genetic variation in the E6 and E7 genes of human papillomavirus type 16 in northeastern Argentina.

The province of Misiones is considered a region with a high mortality rate due to cervical cancer (CC). To gain insight into this problem, we explored the association between genetic variation in the E6 and E7 oncogenes of HPV16 and the risk of CC. We studied 160 women with cytological diagnoses of negative for intraepithelial lesion or malignity, low-grade squamous intraepithelial lesion, and high-grade squamous intraepithelial lesion/CC and a positive test for HPV16 infection. The genetic characterization of E6 and E7 genes was undertaken through PCR amplification and direct Sanger sequencing. Phylogenetic classification was conducted using Bayesian methods. To estimate the odds ratio (OR) for an association between genetic variants in the E6 and E7 genes and the risk of CC, we used ordinal logistic regression adjusted by age. The final data set comprised 112 samples. Diagnostic single-nucleotide polymorphisms (SNPs) and phylogenetic trees confirmed the presence of Lineage A (95.5%) and D (4.5%) in the samples. For the E6 gene, we identified eleven different sequences, with the most common ones being Lineage A E6 350G (58.9%) and E6 350T (37.5%). The E6 350G was associated with progression to HSIL/CC, with an OR of 19.41 (4.95-76.10). The E7 gene was more conserved than E6, probably due to the functional constraints of this small protein. Our results confirmed the association of the E6 350G SNP with a higher risk of developing CC. These data will contribute to understanding the biological bases of CC incidence in this region.

Germline determinants of humoral immune response to HPV-16 protect against oropharyngeal cancer.

Although several oropharyngeal cancer (OPC) susceptibility loci have been identified, most previous studies lacked detailed information on human papillomavirus (HPV) status. We conduct a genome-wide analysis by HPV16 serology status in 4,002 oral cancer cases (OPC and oral cavity cancer (OCC)) and 5,256 controls. We detect four susceptibility loci pointing to a distinct genetic predisposition by HPV status. Our most notable finding in the HLA region, that is now confirmed to be specific of HPV(+)OPC risk, reveal two independent loci with strong protective effects, one refining the previously reported HLA class II haplotype association. Antibody levels against HPV16 viral proteins strongly implicate the protective HLA variants as major determinants of humoral response against L1 capsid protein or E6 oncoprotein suggesting a natural immune response against HPV(+)OPC promoted by HLA variants. This indicates that therapeutic vaccines that target E6 and attenuate viral response after established HPV infections might protect against HPV(+)OPC.

The dynamic interactome of microRNAs and the human papillomavirus in head and neck cancers.

The Human Papillomavirus type 16 is a major etiologic factor for a subset of Head and Neck cancers. These cancers of the oropharyngeal region are growing, and it is expected to exceed cervical cancers in the near future. The major oncogenes E6 and E7 mediate many of the early transformation stages targeting p53 and other tumour suppressor genes. The majority of this regulation is centred on protein coding genes but more recently small non-coding RNAs, such as miRNAs are also regulated by HPV16. However, the system-wide impact of HPV16 on miRNAs is yet to be fully understood. To fully gauge the overall relationship between HPV16 and miRNAs, several studies have devised dynamic interactomes which encompass viral oncogenes, miRNAs and gene targets. These interactomes map potential pathways which permit the identification of possible mechanistic links. Our review will discuss the latest developments in using viral interactomes to understand viral mechanisms and how these approaches may aid in the elucidation of potential druggable pathways.

Genotype distribution of cervical HPV among Caribbean women in a population-based study in Martinique: The DEPIPAPUFR study.

The Caribbean ranks seventh among the world regions most affected by cervical cancer. HPV-prevalence and genotype distributions also differ from regions. Knowledge of HPV genotype profiles is important for patients care and HPV vaccination implementation. The objective of this study was to describe HPV genotype distribution and risk factors in a population-based cohort of women in Martinique. In this study, 1312 women were included and underwent cervical cancer screening with successful sample collection between 2009 and 2014. Sociodemographic and clinical variables were recorded. Cytological examination of cervical vaginal smear was performed and classified(Bethesda). Detection of HPV DNA was performed with the PapilloCheck© Kit from Greiner Bio-one. Genotypes were analyzed for18 high-risk HPV (hrHPV) and 6low-risk HPV(lrHPV) types. A total of 1075 women were included with a mean age of 49.1±10.5 years. HPV prevalence was 27.6% (297/1075) with 19.4% (209/1075) women with only hrHPV, 5.3% (57/1075) with only lrHPV. Multiple infections (hrHPV/lrHPV) were detected in 31/240 cases of hrHPV (12.9%). A total of 353 hrHPV genotypes were analyzed; the most common HPV types were HPV51 (11.0%), HPV68 (10.8%), HPV53 (9.1%) and HPV 52 (7.1%). HPV16 and HPV18 represented respectively 4.8% and 4.0% of hrHPV genotypes. Abnormal cytology was observed in 34 cases (3.2%), with 14 ASCUS (1.3%), 10 LSIL (0.9%), 5 HSIL (0.5%), 3 ASC-H (0.3%) and 2 AGC (0.2%). Fifteen (44.1%) were hrHPV and 4 (14.7%) lrHPV; 7 cases of hrPHV were in the age-group 25-34 years. Among 1041cases of normal cytology, 225 had positive hrHPV detection (21.6%). This is the first population-based study of HPV profiles in our country, and we found a high prevalence of hrHPV. The most common genotypes were HPV51, 68, 53. These results could serve for cancer vaccination strategies and HPV surveillance in Martinique.

CK2 Phosphorylation of Human Papillomavirus 16 E2 on Serine 23 Promotes Interaction with TopBP1 and Is Critical for E2 Interaction with Mitotic Chromatin and the Viral Life Cycle.

During the human papillomavirus 16 (HPV16) life cycle, the E2 protein interacts with host factors to regulate viral transcription, replication, and genome segregation/retention. Our understanding of host partner proteins and their roles in E2 functions remains incomplete. Here we demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 in vitro and in vivo and that E2 is phosphorylated on this residue during the HPV16 life cycle. We investigated the consequences of mutating serine 23 on E2 functions. E2-S23A (E2 with serine 23 mutated to alanine) activates and represses transcription identically to E2-WT (wild-type E2), and E2-S23A is as efficient as E2-WT in transient replication assays. However, E2-S23A has compromised interaction with mitotic chromatin compared with E2-WT. In E2-WT cells, both E2 and TopBP1 levels increase during mitosis compared with vector control cells. In E2-S23A cells, neither E2 nor TopBP1 levels increase during mitosis. Introduction of the S23A mutation into the HPV16 genome resulted in delayed immortalization of human foreskin keratinocytes (HFK) and higher episomal viral genome copy number in resulting established HFK. Remarkably, S23A cells had a disrupted viral life cycle in organotypic raft cultures, with a loss of E2 expression and a failure of viral replication. Overall, our results demonstrate that CK2 phosphorylation of E2 on serine 23 promotes interaction with TopBP1 and that this interaction is critical for the viral life cycle. IMPORTANCE Human papillomaviruses are causative agents in around 5% of all cancers, with no specific antiviral therapeutics available for treating infections or resultant cancers. In this report, we demonstrate that phosphorylation of HPV16 E2 by CK2 promotes formation of a complex with the cellular protein TopBP1 in vitro and in vivo. This complex results in stabilization of E2 during mitosis. We demonstrate that CK2 phosphorylates E2 on serine 23 in vivo and that CK2 inhibitors disrupt the E2-TopBP1 complex. Mutation of E2 serine 23 to alanine disrupts the HPV16 life cycle, hindering immortalization and disrupting the viral life cycle, demonstrating a critical function for this residue.

Detection of Human Papillomavirus Integration in Brain Metastases from Oropharyngeal Tumors by Targeted Sequencing.

Human papillomavirus (HPV) positive and negative head and neck squamous cell carcinoma (HNSCC) are known to have differential phenotypes, including the incidence and location of metastases. HPV positive (HPV+) HNSCC are more likely to metastasize to distant sites, such as the lung, brain, and skin. Among these locations, metastasis to the brain is a rare event, and little is known about specific risk factors for this phenotype. In this report, we describe two patients who developed brain metastases from HNSCC. Both patient tumors had p16INK4a overexpression, suggesting these tumors were HPV+. This was confirmed after PCR, in situ hybridization, and mass spectrometry detected the presence of HPV type 16 (HPV16) DNA, RNA and protein. To further characterize the presence of HPV16, we used a target enrichment strategy on tumor DNA and RNA to isolate the viral sequences from the brain metastases. Analysis by targeted next generation sequencing revealed that both tumors had the HPV genome integrated into the host genome at known hotspots, 8q24.21 and 14q24.1. Applying a similar target enrichment strategy to a larger cohort of HPV+ HNSCC brain metastases could help to identify biomarkers that can predict metastasis and/or identify novel therapeutic options.

Risks for cervical abnormalities in women with non-16/18 high-risk human papillomavirus infections in south Shanghai, China.

The study was aimed to analyze the prevalence characteristics of non-16/18 high-risk human papillomaviruses (HR-HPV) and the related risks for cervical abnormalities in south Shanghai. A total of 2291 HPV women who had been referred for a colposcopy due to HPV infection from @@@@@2016.12 to 2019.6 were enrolled. Combined with liquid-based thin-layer cell test (TCT) and pathological results of cervical biopsy, the infection spectrum and pathogenic risk of non-16/18 HR-HPV in local population were investigated. The results showed that the single HR-HPV infection rate was significantly higher than that of multiple infection, and the five most frequently detected types were HPV16, HPV52, HPV18, HPV53, HPV58 in the group. The total proportion of non-16/18 HR-HPV infection was 68.22%, more than twice of HPV16/18. In cases with high-grade cervical intraepithelial lesions (HSIL) or cervical cancer, non-16/18 HR-HPV infections account for 50.84% (single infection: 28.57%, multiple infection: 22.27%). The risk of cervical abnormalities caused by single HPV infection was ranked as HPV16 > HPV52 > HPV18 = HPV58 > HPV51 > HPV53 = HPV56 > others. Notably, among non-16/18 HR-HPV infected patients with HSIL/cancer lesions, the omission diagnostic rate of TCT was 62.81%. The infection rate of non-16/18 HR-HPV in whole study population was much higher than that of 16/18 type, and the infection rate of the former was also slightly higher in patients with HSIL and cancer. Due to the high omission diagnostic rate of TCT, we suggest patients with persistent non-16/18 HPV infection should undergo colposcopy biopsy to reduce missed detection of HSIL and cancers.

Proteasomal degradation of p130 facilitate cell cycle deregulation and impairment of cellular differentiation in high-risk Human Papillomavirus 16 and 18 E7 transfected cells.

The High-Risk Human Papillomaviruses (HR-HPVs) 16 and 18 are known to cause cervical cancer, which is primarily attributed to E6 and E7 oncoproteins. In addition, recent studies have focused on the vital role of the p130 pocket protein as an oncosuppressor to limit the expression of E2F transcription factors required for cell cycle progression. In view of this, the current study was conducted to investigate the mechanism by which transfection with HPV16/18 E7 leads to the deregulation of the host cell cycle, altering the localisation of p130, and expression of differentiation genes in Human Keratinocytes (HaCaT) cells. Co-immunoprecipitation, Western blot analysis, immunofluorescence microscopy, flow cytometry, quantitative-Polymerase Chain Reaction (qPCR), and the inhibition of p130 by MG132 inhibitor were employed to investigate the loss of p130 and its disruption in HPV 16/18 E7-transfected HaCaT cells. The HPV16- and HPV18-transformed cells, known as CaSki and HeLa, respectively, were also used to complement the ectopic expressions of E7 in HaCaT cells. Normal keratinocytes displayed higher level of p130 expression than HPV-transformed cells. In addition, the immunofluorescence analysis revealed that both HPV 16/18 E7-transfected HaCaT and HPV-transformed cells exhibited higher level of cytoplasmic p130 compared to nuclear p130. A significant increase in the number of S/G2 phase cells in HPV-transformed cells was also recorded since E7 has been shown to stimulate proliferation through the deactivation of Retinoblastoma Protein (pRB)-dependent G1/S checkpoint. Furthermore, the findings recorded the down-regulation of keratinocyte differentiation markers, namely p130, keratin10, and involucrin. The proteasomal degradation of the exported p130 confirmed the cellular localisation pattern of p130, which was commonly observed in cancerous cells. The findings provide strong evidence that the localisation of nuclear p130 nuclear was disrupted by HPV16/18 E7 led to the deregulation of the cell cycle and the impairment of cellular differentiation ultimately lead to cellular transformation.

Application of the Bethesda system of reporting for cervical cytology to evaluate human papilloma virus induced changes in oral leukoplakia, oral squamous cell carcinoma, and oropharyngeal squamous cell carcinoma: A cytomorphological and genetic study.

BACKGROUND: Human papilloma virus (HPV) has a well-established carcinogenic role in certain head and neck cancers. These HPV associated cancers possess unique clinicopathological behavior and exhibits better prognosis than their negative counterparts. Detection through polymerase chain reaction (PCR) has been considered as the "gold standard" but imposes burden in low resource settings. Therefore, in the present study, we assessed the validity of cytomorphological features for the detection of HPV in oral leukoplakia (OL), oral squamous cell carcinoma (OSCC), and oropharyngeal squamous cell carcinoma (OPSCC). METHODOLOGY: This study included 63 subjects comprising of 25 OL, 26 OSCC, and 12 OPSCC cases. Exfoliated cells were collected and processed for PCR followed by Papanicolaou staining and subsequent grading. Additionally the non-classical signs were evaluated and statistical analysis included Chi-square and Spearman's test. RESULT: 23/63 (36.5%) cases showed PCR positivity for HPV16. Most of the cytomorphological features showed significant correlation for the presence of HPV. A greater sensitivity and specificity was observed in the Bethesda system for reporting cervical cytology (TBS) than the Papanicolaou grading system. CONCLUSION: We conclude that the non-classic cytological features could be employed in the detection of HPV in low resource settings with improved sensitivity. Liquid based cytology graded using TBS could be suitable for oral cytology in the detection of early atypical changes.

Identification of High-Risk Human Papillomavirus DNA, p16, and E6/E7 Oncoproteins in Laryngeal and Hypopharyngeal Squamous Cell Carcinomas.

Human papillomavirus (HPV) was proven to play a significant role in cancer development in the oropharynx. However, its role in the development of laryngeal (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC) remains to be clarified. High-risk HPV (HR-HPV) viral proteins E6 and E7 are considered to be pertinent to HPV-related carcinogenesis. Hence, our aim was to estimate LSCC and HPSCC for HR-HPV DNA, p16, and E6/E7 oncoprotein status by using molecular virology and immunohistochemistry methods. The prevalence of HPV16 infection was 22/41 (53.7%) and 20/31 (64.5%) for LSCC and HPSCC, accordingly. The majority of HPV16+ tumor samples were stage III or IV. In most samples, the presence of either HPV16 E6 or HPV16 E7 viral protein in dysplastic or tumor cells was confirmed using immunohistochemistry. Our results suggest a high prevalence of HPV16 as a primary HR-HPV type in LSCC and HPSCC. The lack of HPV E6/E7 oncoproteins in some tumor samples may suggest either the absence of viral integration or the presence of other mechanisms of tumorigenesis. The utilization of p16 IHC as a surrogate marker of HR-HPV infection is impractical in LSCC and HPSCC.

Comprehensive analysis of ceRNA networks in HPV16- and HPV18-mediated cervical cancers reveals XIST as a pivotal competing endogenous RNA.

Cervical cancer (CC) is one of the most common cancers in women worldwide, being closely related to high-risk human papillomavirus (HR-HPVs). After a particular HR-HPV infects a cervical cell, transcriptional changes in the host cell are expected, including the regulation of lncRNAs, miRNAs, and mRNAs. Such transcripts may work independently or integrated in complex molecular networks - as in competing endogenous RNA (ceRNA) networks. In our research, we gathered transcriptome data from samples of HPV16/HPV18 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), from The Cancer Genome Atlas (TCGA) project. Using GDCRNATools, we identified ceRNA networks that differentiate HPV16- from HPV18-mediated CESC. For HPV16-CESC, three lncRNA-mRNA co-expressed pairs were reported, all led by the X-inactive specific transcript (XIST): XIST | DLG5, XIST | LGR4, and XIST | ZNF81. The XIST | LGR4 and XIST | ZNF81 pairs shared 11 miRNAs, suggesting an increased impact on their final biological effect. XIST also stood out as an important lncRNA in HPV18-CESC, leading 35 of the 42 co-expressed pairs. Some mRNAs, such as ADAM9 and SLC38A2, emerged as important players in the ceRNA regulatory networks due to sharing a considerable amount of miRNAs with XIST. Furthermore, some XIST-associated axes, namely XIST | miR-23a-3p | LGR4 and XIST | miR-30b-5p or miR-30c-5p or miR-30e-5p I ADAM9, had a significant impact on the overall survival of HPV16- and HPV18-CESC patients, respectively. Together, these data suggest that XIST has an important role in HPV-mediated tumorigenesis, which may implicate different molecular signatures between HPV16 and HPV18-associated tumors.

Non-Metabolic Functions of PKM2 Contribute to Cervical Cancer Cell Proliferation Induced by the HPV16 E7 Oncoprotein.

Pyruvate kinase M2 (PKM2) mainly catalyzes glycolysis, but it also exerts non-glycolytic functions in several cancers. While it has been shown to interact with the human papillomavirus 16 (HPV16) E7 oncoprotein, the functional significance of PKM2 in HPV-associated cervical cancer has been elusive. Here, we show that HPV16 E7 increased the expression of PKM2 in cervical cancer cells. TCGA data analyses revealed a higher level of PKM2 in HPV+ than HPV- cervical cancers and a worse prognosis for patients with high PKM2 expression. Functionally, we demonstrate that shRNA-mediated PKM2 knockdown decreased the proliferation of HPV+ SiHa cervical cancer cells. PKM2 knockdown also inhibited the E7-induced proliferation of cervical cancer cells. ML265 activating the pyruvate kinase function of PKM2 inhibited cell cycle progression and colony formation. ML265 treatments decreased phosphorylation of PKM2 at the Y105 position that has been associated with non-glycolytic functions. On the contrary, HPV16 E7 increased the PKM2 phosphorylation. Our results indicate that E7 increases PKM2 expression and activates a non-glycolytic function of PKM2 to promote cervical cancer cell proliferation.

A cross-sectional study exploring triage of human papillomavirus (HPV)-positive women by visual assessment, manual and computer-interpreted cytology, and HPV-16/18-45 genotyping in Cameroon.

BACKGROUND: High-risk human papillomavirus (HPV)-positive women require triage to identify those at higher risk of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). We aimed to compare visual assessment of the cervix, manual cytology and automated cytology as triage tests to screen HPV-positive women, and to assess over-treatment rates after visual assessment and over-referral rates to colposcopy after cytology. METHODS: The present cross-sectional study is nested in a large prospective screening trial in Cameroon. Evaluations of the tests have been conducted individually and in combination with HPV-16/HPV-18/45 genotyping. For the evaluation of over-treatment and colposcopic over-referral, we simulated two screening scenarios: (1) one-visit scenario (test-triage-and-treatment); and (2) two-visit scenario (test-triage-and-colposcopy). RESULTS: 1582 women with a median age of 40 years (IQR 35-45) performed self-sampling for HPV testing, of which 294 (18.6%) were HPV-positive, and 12.2% had CIN2+. Sensitivities for CIN2+ detection were 77.1% for visual assessment, 80.0% for manual cytology, and 84.8% for automated cytology. Sensitivity of combined tests was higher compared with single tests. The highest sensitivity was obtained by the combination of genotyping and automated cytology (91.2%). In the one-visit scenario, the over-treatment rate was 83.9% in referred women, with a ratio of 6.2 treated women per CIN2+. In the two-visit scenario, the lowest over-referral rate would have been under manual cytology (45.0%), with a ratio of 1.8 referred women per CIN2+. Single and combined triage strategies by automated cytology gave rise to over-referral rates of 69.2% and 76.7%, respectively, and a ratio of 3.2 and 4.3 referred women per CIN2+, respectively. DISCUSSION: Triage of HPV-positive women using a combination of genotyping and automated cytology for CIN2+ detection may provide public benefits in low- and middle-income countries.

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.

Genetic variants of HPV-16 and their geographical and anatomical distribution in men: A systematic review with meta-analysis.

BACKGROUND: The prevalence of Human Papillomavirus type 16 (HPV-16) variants in men and the association with tumor development has not been fully investigated. We estimated the prevalence of genital, anal, and oral HPV-16 infections in men through a systematic review and meta-analysis. METHODS: Seven databases were searched and included studies that identified HPV-16 positive males, HPV-16 variants (lineages/sublineages), and indicated the sample's anatomical origin. This protocol is registered in PROSPERO (CRD42020178013). RESULTS: The database searches yielded 14 studies including 445 HPV-16 positive samples classified as lineage A (n = 390), lineage D (n = 43), lineage B (n = 10), and lineage C (n = 2) variants. Lineage A variants predominated among the anatomical sites and the diverse geographical regions. CONCLUSIONS: HPV-16 lineages vary according to anatomical and geographical region. According to this preliminary evaluation of the current literature, we hypothesize that, similar to women, specific HPV-16 variants may also be associated to increased cancer risk in men.

Modeling and Molecular Dynamics of the 3D Structure of the HPV16 E7 Protein and Its Variants.

The oncogenic potential of high-risk human papillomavirus (HPV) is predicated on the production of the E6 and E7 oncoproteins, which are responsible for disrupting the control of the cell cycle. Epidemiological studies have proposed that the presence of the N29S and H51N variants of the HPV16 E7 protein is significantly associated with cervical cancer. It has been suggested that changes in the amino acid sequence of E7 variants may affect the oncoprotein 3D structure; however, this remains uncertain. An analysis of the structural differences of the HPV16 E7 protein and its variants (N29S and H51N) was performed through homology modeling and structural refinement by molecular dynamics simulation. We propose, for the first time, a 3D structure of the E7 reference protein and two of Its variants (N29S and H51N), and conclude that the mutations induced by the variants in N29S and H51N have a significant influence on the 3D structure of the E7 protein of HPV16, which could be related to the oncogenic capacity of this protein.

Risk factors for HPV infection and high-grade cervical disease in sexually active Japanese women.

In Japan, recommendations for HPV vaccines were suspended in 2013 due to unfounded safety fears. Although vaccine opponents claim modifying sexual behavior can prevent cervical cancer, no comprehensive data exist on sexual behavior and the risk of high-grade cervical disease in a Japanese population. This study investigates sexual behavior and the risk of HPV infection and cervical disease in 3968 women aged 20-41 yrs undergoing cervical screening between April 2014 and March 2016. Mean age at first intercourse was 18.4 yrs ± 2.8 and 32% of women reported ≥ 6 lifetime sexual partners. In regression analyses, number of partners was a significant risk factor for HPV infection. However, for high-grade disease (CIN2+), when HPV genotype was adjusted for, number of partners was not statistically significant. The greatest risk factor was an HPV16/18 infection (adjusted odds ratio 113.7, 95% CI: 40.8-316.9). In conclusion, we found that having an HPV16/18 infection and not sexual behavior was the most significant risk factor for high grade cervical disease in young Japanese women. These infections can be prevented by a highly effective vaccine and we recommend that the Japanese government resume proactive recommendations for the HPV vaccine immediately.

Delta-Like Ligand-Notch1 Signaling Is Selectively Modulated by HPV16 E6 to Promote Squamous Cell Proliferation and Correlates with Cervical Cancer Prognosis.

Human papillomavirus (HPV) drives high-grade intraepithelial neoplasia and cancer; for unknown reasons, this occurs most often in the cervical transformation zone. Either mutation or HPV E6-driven inhibition of Notch1 can drive neoplastic development in stratified squamous epithelia. However, the contribution of Notch1 and its Delta-like ligands (DLL) to site susceptibility remains poorly understood. Here, we map DLL1/DLL4 expression in cell populations present in normal cervical biopsies by immunofluorescence. In vitro keratinocyte 2D monolayer models, growth assays, and organotypic raft cultures were used to assess the functional role of DLL-Notch signaling in uninfected cells and its modulation by HPV16 in neoplasia. An RNA sequencing-based gene signature was used to suggest the cell of origin of 279 HPV-positive cervical carcinomas from The Cancer Genome Atlas and to relate this to disease prognosis. Finally, the prognostic impact of DLL4 expression was investigated in three independent cervical cancer patient cohorts. Three molecular cervical carcinoma subtypes were identified, with reserve cell tumors the most common and linked to relatively good prognosis. Reserve cells were characterized as DLL1-/DLL4+, a proliferative phenotype that is temporarily observed during squamous metaplasia and wound healing but appears to be sustained by HPV16 E6 in raft models of low-grade and, more prominently, high-grade neoplasia. High expression of DLL4 was associated with an increased likelihood of cervical cancer-associated death and recurrence. Taken together, DLL4-Notch1 signaling reflects a proliferative cellular state transiently present during physiologic processes but inherent to cervical reserve cells, making them strongly resemble neoplastic tissue even before HPV infection has occurred. SIGNIFICANCE: This study investigates cervical cancer cell-of-origin populations and describes a DLL-Notch1 phenotype that is associated with disease prognosis and that might help identify cells that are susceptible to HPV-induced carcinogenesis.