HPV16 E7 Genetic Conservation Is Critical to Carcinogenesis.

Although most cervical human papillomavirus type 16 (HPV16) infections become undetectable within 1-2 years, persistent HPV16 causes half of all cervical cancers. We used a novel HPV whole-genome sequencing technique to evaluate an exceptionally large collection of 5,570 HPV16-infected case-control samples to determine whether viral genetic variation influences risk of cervical precancer and cancer. We observed thousands of unique HPV16 genomes; very few women shared the identical HPV16 sequence, which should stimulate a careful re-evaluation of the clinical implications of HPV mutation rates, transmission, clearance, and persistence. In case-control analyses, HPV16 in the controls had significantly more amino acid changing variants throughout the genome. Strikingly, E7 was devoid of variants in precancers/cancers compared to higher levels in the controls; we confirmed this in cancers from around the world. Strict conservation of the 98 amino acids of E7, which disrupts Rb function, is critical for HPV16 carcinogenesis, presenting a highly specific target for etiologic and therapeutic research.

BRCA1 deficiency enhances the aggressiveness of breast cancer cells expressing HPV16 oncoproteins.

BACKGROUND INFORMATION: The precise etiology of breast cancer is not completely understood, although women with BRCA1 gene mutations have a significantly increased risk of developing the disease. In addition, sporadic breast cancer is frequently associated with decreased BRCA1 gene expression. Growing evidence of Human papillomaviruses (HPVs) infections in breast tumors has raised the possibility of the involvement of HPVs in the pathogenesis of breast cancer. We investigated whether the effects of HPV oncoproteins E6 and E7 were influenced by the expression levels of BRCA1. HPV16E6E7 (prototype or E6D25E/E7N29S Asian variant type) were stably expressed in MDA-MB231 breast cancer cells, wild type for BRCA1, or with BRCA1 knocked down. RESULTS: Expression of HPV16E6E7 oncogenes did not affect BRCA1 levels and the abundance of HPV16E6E7 was not altered by BRCA1 knockdown. BRCA1 levels did not alter HPV16E6E7-dependent degradation of G1-S cell cycle proteins p53 and pRb. However, we found that the expression of G2-M cell cycle protein cyclin B1 enhanced by HPV16E6E7 was impacted by BRCA1 levels. Especially, we found the correlation between BRCA1 and cyclin B1 expression and this was also confirmed in breast cancer samples from a Thai cohort. We further demonstrated that the combination of HPV oncoproteins and low levels of BRCA1 protein appears to enhance proliferation and invasion. Transactivation activities of HPV16E6E7 on genes regulating cell proliferation and invasion (TGF-ß and vimentin) were significantly increased in BRCA1-deficient cells. CONCLUSIONS: Our results indicate that a deficiency of BRCA1 promotes the transactivation activity of HPV16E6E7 leading to increase of cell proliferation and invasion. SIGNIFICANCE: HPV infection appears to have the potential to enhance the aggressiveness of breast cancers, especially those deficient in BRCA1.

Long-read sequencing reveals the structural complexity of genomic integration of HPV DNA in cervical cancer cell lines.

BACKGROUND: Cervical cancer (CC) causes more than 311,000 deaths annually worldwide. The integration of human papillomavirus (HPV) is a crucial genetic event that contributes to cervical carcinogenesis. Despite HPV DNA integration is known to disrupt the genomic architecture of both the host and viral genomes in CC, the complexity of this process remains largely unexplored. RESULTS: In this study, we conducted whole-genome sequencing (WGS) at 55-65X coverage utilizing the PacBio long-read sequencing platform in SiHa and HeLa cells, followed by comprehensive analyses of the sequence data to elucidate the complexity of HPV integration. Firstly, our results demonstrated that PacBio long-read sequencing effectively identifies HPV integration breakpoints with comparable accuracy to targeted-capture Next-generation sequencing (NGS) methods. Secondly, we constructed detailed models of complex integrated genome structures that included both the HPV genome and nearby regions of the human genome by utilizing PacBio long-read WGS. Thirdly, our sequencing results revealed the occurrence of a wide variety of genome-wide structural variations (SVs) in SiHa and HeLa cells. Additionally, our analysis further revealed a potential correlation between changes in gene expression levels and SVs on chromosome 13 in the genome of SiHa cells. CONCLUSIONS: Using PacBio long-read sequencing, we have successfully constructed complex models illustrating HPV integrated genome structures in SiHa and HeLa cells. This accomplishment serves as a compelling demonstration of the valuable capabilities of long-read sequencing in detecting and characterizing HPV genomic integration structures within human cells. Furthermore, these findings offer critical insights into the complex process of HPV16 and HPV18 integration and their potential contribution to the development of cervical cancer.

Bioinformatics Analysis Reveals E6 and E7 of HPV 16 Regulate Metabolic Reprogramming in Cervical Cancer, Head and Neck Cancer, and Colorectal Cancer through the PHD2-VHL-CUL2-ELOC-HIF-1α Axis.

Human papillomavirus 16 (HPV 16) infection is associated with several types of cancer, such as head and neck, cervical, anal, and penile cancer. Its oncogenic potential is due to the ability of the E6 and E7 oncoproteins to promote alterations associated with cell transformation. HPV 16 E6 and E7 oncoproteins increase metabolic reprogramming, one of the hallmarks of cancer, by increasing the stability of hypoxia-induced factor 1 α (HIF-1α) and consequently increasing the expression levels of their target genes. In this report, by bioinformatic analysis, we show the possible effect of HPV 16 oncoproteins E6 and E7 on metabolic reprogramming in cancer through the E6-E7-PHD2-VHL-CUL2-ELOC-HIF-1α axis. We proposed that E6 and E7 interact with VHL, CUL2, and ELOC in forming the E3 ubiquitin ligase complex that ubiquitinates HIF-1α for degradation via the proteasome. Based on the information found in the databases, it is proposed that E6 interacts with VHL by blocking its interaction with HIF-1α. On the other hand, E7 interacts with CUL2 and ELOC, preventing their binding to VHL and RBX1, respectively. Consequently, HIF-1α is stabilized and binds with HIF-1ß to form the active HIF1 complex that binds to hypoxia response elements (HREs), allowing the expression of genes related to energy metabolism. In addition, we suggest an effect of E6 and E7 at the level of PHD2, VHL, CUL2, and ELOC gene expression. Here, we propose some miRNAs targeting PHD2, VHL, CUL2, and ELOC mRNAs. The effect of E6 and E7 may be the non-hydroxylation and non-ubiquitination of HIF-1α, which may regulate metabolic processes involved in metabolic reprogramming in cancer upon stabilization, non-degradation, and translocation to the nucleus.

Final outcomes analysis of the cell product SQZ-PBMC-HPV Phase 1 trial in incurable HPV16+ solid tumors shows improved overall survival in patients with increased CD8+ T cell tumor infiltration.

Cancer vaccines strive to induce robust, antigen-targeted, T-cell-mediated immune responses but have struggled to produce meaningful regression in solid tumors. An autologous cell vaccine, SQZ-PBMC-HPV, was developed by SQZ Biotechnologies using microfluidic squeezing technology to load PBMCs with HPV16 E6 and E7 antigens in HLA-A*02+ patients. The SQZ-PBMC-HPV-101 Phase 1 trial (NCT04084951) enrolled patients with incurable HPV16+ cancers. Here, we present a post hoc analysis of the relationship between Posttreatment CD8+ T cell infiltration and patient outcomes. SQZ-PBMC-HPV was administered as monotherapy every 3 weeks. Tumor samples were collected pre-dose and post-dose 4 weeks after treatment start. Biomarkers including CD8, MHC-I, E6, E7, GZMB, and Ki67 were evaluated by immunohistochemistry, immunofluorescence, and RNA in situ hybridization, and were correlated with clinical response, survival, and drug product composition. Eighteen patients had paired pre- and post-dose biopsies. Six (33%) had an increase in CD8+ T cell density in tumor parenchyma between screening and C2D8. Patients with increased CD8+ T cell density had improved disease control rate (66.7% vs 16.7%) and median overall survival (606.5 days vs 170.0 days, p = 0.0078). Drug product was significantly enriched for higher T cells and lower monocytes in the increased CD8+ T cell density group. In patients with incurable HPV16+ solid tumors treated with SQZ-PBMC-HPV, an increase in CD8+ T cell density within the tumor parenchyma was associated with superior disease control rate and overall survival. The product composition for patients with increased CD8+ T cell density was enriched for T cells.

Human Papillomavirus Genome Copy Number Is Maintained by S-Phase Amplification, Genome Loss to the Cytosol during Mitosis, and Degradation in G1 Phase.

The current model of human papillomavirus (HPV) replication is comprised of three modes of replication. Following infectious delivery, the viral genome is amplified during the establishment phase to reach up to some hundred copies per cell. The HPV genome copy number remains constant during the maintenance stage. The differentiation of infected cells induces HPV genome amplification. Using highly sensitive in situ hybridization (DNAscope) and freshly HPV16-infected as well as established HPV16-positive cell lines, we observed that the viral genome is amplified in each S phase of undifferentiated keratinocytes cultured as monolayers. The nuclear viral genome copy number is reset to pre-S-phase levels during mitosis. The majority of the viral genome fails to tether to host chromosomes and is lost to the cytosol. Cytosolic viral genomes gradually decrease during cell cycle progression. The loss of cytosolic genomes is blocked in the presence of NH4Cl or other drugs that interfere with lysosomal acidification, suggesting the involvement of autophagy in viral genome degradation. These observations were also made with HPV31 cell lines obtained from patient samples. Cytosolic viral genomes were not detected in UMSCC47 cells carrying integrated HPV16 DNA. Analyses of organotypic raft cultures derived from keratinocytes harboring episomal HPV16 revealed the presence of cytosolic viral genomes as well. We conclude that HPV maintains viral genome copy numbers by balancing viral genome amplification during S phase with the loss of viral genomes to the cytosol during mitosis. It seems plausible that restrictions to viral genome tethering to mitotic chromosomes reset genome copy numbers in each cell cycle. IMPORTANCE HPV genome maintenance is currently thought to be achieved by regulating the expression and activity of the viral replication factors E1 and E2. In addition, the E8^E2 repressor has been shown to be important for restricting genome copy numbers by competing with E1 and E2 for binding to the viral origin of replication and by recruiting repressor complexes. Here, we demonstrate that the HPV genome is amplified in each S phase. The nuclear genome copy number is reset during mitosis by a failure of the majority of the genomes to tether to mitotic chromosomes. Rather, HPV genomes accumulate in the cytoplasm of freshly divided cells. Cytosolic viral DNA is degraded in G1 in a lysosome-dependent manner, contributing to the genome copy reset. Our data imply that the mode of replication during establishment and maintenance is the same and further suggest that restrictions to genome tethering significantly contribute to viral genome maintenance.

Experimental Support for Human Papillomavirus Genome Amplification Early after Infectious Delivery.

Even though replication and transcription of human papillomavirus type 16 (HPV16) has been intensively studied, little is known about immediate-early events of the viral life cycle due to the lack of an efficient infection model allowing genetic dissection of viral factors. We employed the recently developed infection model (Bienkowska-Haba M, Luszczek W, Myers JE, Keiffer TR, et al. 2018. PLoS Pathog 14:e1006846) to investigate genome amplification and transcription immediately after infectious delivery of viral genome to nuclei of primary keratinocytes. Using 5-ethynyl-2'-deoxyuridine (EdU) pulse-labeling and highly sensitive fluorescence in situ hybridization, we observed that the HPV16 genome is replicated and amplified in an E1- and E2-dependent manner. Knockout of E1 resulted in failure of the viral genome to replicate and amplify. In contrast, knockout of the E8^E2 repressor led to increased viral genome copy number, confirming previous reports. Genome copy control by E8^E2 was confirmed for differentiation-induced genome amplification. Lack of functional E1 had no effect on transcription from the early promoter, suggesting that viral genome replication is not required for p97 promoter activity. However, infection with an HPV16 mutant virus defective for E2 transcriptional function revealed a requirement of E2 for efficient transcription from the early promoter. In the absence of the E8^E2 protein, early transcript levels are unaltered and even decreased when normalized to genome copy number. Surprisingly, a lack of functional E8^E2 repressor did not affect E8^E2 transcript levels when normalized to genome copy number. These data suggest that the main function of E8^E2 in the viral life cycle is to control genome copy number. IMPORTANCE It is being assumed that human papillomavirus (HPV) utilizes three different modes of replication during its life cycle: initial amplification during the establishment phase, genome maintenance, and differentiation-induced amplification. However, HPV16 initial amplification was never formally proven due to a lack of an infection model. Using our recently established infection model (Bienkowska-Haba M, Luszczek W, Myers JE, Keiffer TR, et al. 2018. PLoS Pathog 14:e1006846), we demonstrate herein that viral genome is indeed amplified in an E1- and E2-dependent manner. Furthermore, we find that the main function of the viral repressor E8^E2 is to control viral genome copy number. We did not find evidence that it regulates its own promoter in a negative feedback loop. Our data also suggest that the E2 transactivator function is required for stimulation of early promoter activity, which has been debated in the literature. Overall, this report confirms the usefulness of the infection model for studying early events of the HPV life cycle using mutational approaches.

Naturally developed HPV16 antibodies and risk of newly detected cervical HPV infection outcomes.

Little is known about the protection conferred by antibodies from natural human papillomavirus (HPV) infection. Our objective was to evaluate the association between HPV16 seroreactivity and HPV16 redetection, newly detected HPV infections, and loss of HPV DNA detection during follow-up. We analyzed data from 2462 unvaccinated Brazilian women. HPV16 IgG and neutralizing antibodies at baseline were assessed by enzyme-linked immunosorbent assay (n = 1975) and by the pseudovirus-based papillomavirus neutralization assay (n = 487). HPV detection, genotyping, and viral load were assessed by PCR-based methods. The associations were analyzed by Cox proportional hazards models. We observed a positive association between HPV16 IgG seroreactivity and redetection of HPV16 infections. Age-adjusted hazard ratios (HR) with 95% confidence intervals (CI) ranged from 2.45 (1.04-5.74) to 5.10 (1.37-19.00). Positive associations were also observed between HPV16 IgG antibodies and (1) newly detected HPV infections by genotypes unrelated to HPV16 (age-adjusted HR [95% CI] = 1.32 [1.08-1.2]) and (2) loss of detection of HPV infections by genotypes unrelated to HPV16 (age-adjusted HR [95% CI] = 1.24 [1.03-1.50]). Naturally developed HPV16 antibodies do not prevent recurrent HPV infections. Overall HPV16 IgG and neutralizing antibodies seem to be serological markers for latent or past infections.

Survival benefits of human papillomavirus 16 infection in patients with esophageal squamous cell carcinoma undergoing chemoradiotherapy: A retrospective cohort study.

The role of human papillomavirus 16 (HPV 16) in esophageal squamous cell carcinoma (ESCC) remains uncertain. Therefore, this study aimed to investigate the prevalence of HPV 16 in patients with ESCC and its impact on theirprognosis. HPV 16 was detected using FISH, and TP53 status was evaluated via immunohistochemistry. The factors influencing prognosis were ananalyzed using the Log-rank test and Cox regression analyses. Among 178 patients with ESCC, 105 and 73 patients were categorized into concurrent chemoradiotherapy (CCRT) and postoperative chemoradiotherapy (POCRT) cohorts, respectively. Among 178 patients, 87 (48.87%) tested positive for HPV 16. Log-rank tests revealed that the overall survival (OS) of patients with ESCC who were HPV 16-positive was longer than that of those who were HPV 16-negative (median OS: 57 months vs. 27 months, p < 0.01**). HPV 16 infection and TP53 mutation status were identified as independent events. The OS of patients with mutant TP53 who were HPV 16-positive was longer than that of those who were HPV 16-negative in both CCRT and POCRT cohorts (p = 0.002** for CCRT cohorts and p = 0.0023** for POCRT cohorts). Conversely, HPV 16 infection had no effect on OS in the wild-type TP53 subgroup (p = 0.13 and 0.052 for CCRT and POCRT cohorts, respectively). As a conclusion, the positive rate of HPV 16 in ESCC in this study was 48.87% (87/178). Among the patients with ESCC who had TP53 mutation, those who were HPV 16-positive exhibited a better prognosis than those who were HPV 16-negative.

Advances in human papillomavirus detection and molecular understanding in head and neck cancers: Implications for clinical management.

Head and neck cancers (HNCs), primarily head and neck squamous cell carcinoma (HNSCC), are associated with high-risk human papillomavirus (HR HPV), notably HPV16 and HPV18. HPV status guides treatment and predicts outcomes, with distinct molecular pathways in HPV-driven HNSCC influencing survival rates. HNC incidence is rising globally, with regional variations reflecting diverse risk factors, including tobacco, alcohol, and HPV infection. Oropharyngeal cancers attributed to HPV have significantly increased, particularly in regions like the United States. The HPV16 genome, characterized by oncoproteins E6 and E7, disrupts crucial cell cycle regulators, including tumor protein p53 (TP53) and retinoblastoma (Rb), contributing to HNSCC pathogenesis. P16 immunohistochemistry (IHC) is a reliable surrogate marker for HPV16 positivity, while in situ hybridization and polymerase chain reaction (PCR) techniques, notably reverse transcription-quantitative PCR (RT-qPCR), offer sensitive HPV detection. Liquid-based RT-qPCR, especially in saliva, shows promise for noninvasive HPV detection, offering simplicity, cost-effectiveness, and patient compliance. These molecular advancements enhance diagnostic accuracy, guide treatment decisions, and improve patient outcomes in HNC management. In conclusion, advances in HPV detection and molecular understanding have significant clinical management implications. Integrating these advancements into routine practice could ultimately improve patient outcomes.

High prevalence of high-risk HPV genotypes in individuals attending an infectious diseases clinic from 2018 to 2022 in Milan, Italy.

Human papillomavirus (HPV) is the most common sexually transmitted infection, linked to several types of lesions. HPV, specifically HPV 16, accounts for most of anal cancer cases. In this study, we evaluated the proportion of samples tested positive for HPV and characterized genotypes distribution in anal specimens collected from individuals at risk of anal HPV infection attending from 2018 to 2022 a large Infectious Diseases Department in Italy. The presence of HPV DNA was investigated through a commercial kit detecting 12 HR-HPV, 8 probable/possible HR-HPV, and 8 LR-HPV genotypes. Among 1514 samples, 84% (1266/1514) resulted positive for any type of HPV. The prevalence of high-risk HPV types remained high during all the years of the study period, from 2018 to 2022, ranging from 65% to 73%. Most of HR-HPV, LR-HPV and HPV 16 positive samples were collected from men >45 years. HPV 16 was also the most frequent type in men and women. We did not observe significant variations between years in detection of HR-HPV, instead of LR-HPV, that significantly decreased. In conclusion, the high prevalence of oncogenic HPV genotypes underlines the necessity of clear anal HPV screening guidelines and, along with frequent HR-HPV coinfections, reinforces the urge to intensify the anti-HPV vaccination campaign.

Changes in intrahost genetic diversity according to lesion severity in longitudinal HPV16 samples.

Human papillomavirus type 16 (HPV16) is the most common cause of cervical cancer, but most infections are transient with lesions not progressing to cancer. There is a lack of specific biomarkers for early cancer risk stratification. This study aimed to explore the intrahost HPV16 genomic variation in longitudinal samples from HPV16-infected women with different cervical lesion severity (normal, low-grade, and high-grade). The TaME-seq deep sequencing protocol was used to generate whole genome HPV16 sequences of 102 samples collected over time from 40 individuals. Single nucleotide variants (SNVs) and intrahost SNVs (iSNVs) were identified in the viral genomes. A majority of individuals had a unique set of SNVs and these SNVs were stable over time. Overall, the number of iSNVs and APOBEC3-induced iSNVs were significantly lower in high-grade relative to normal and low-grade samples. A significant increase in the number of APOBEC3-induced iSNVs over time was observed for normal samples when compared to high-grade. Our results indicates that the lower incidence of iSNVs and APOBEC3-induced iSNVs in high-grade lesions may have implications for novel biomarkers discoveries, potentially aiding early stratification of HPV-induced cervical precancerous lesions.

Should we use risk selection tests for HPV 16 and/or 18 positive cases: Comparison of p16/Ki67 and cytology.

Major screening abnormalities in precolposcopic stage are tests results that imply direct referral to colposcopy (and/or expedited treatment) without performing additional high-grade squamous intraepithelial lesions or worse (HSIL+) risk selection testing. Currently, both clinically validated HSIL+ risk selection tests, reflex cytology and reflex p16/Ki67 dual staining (DS), are being compared for use in primary human papillomavirus (HPV)-based screening to avoid possible overtreatment, but there is still no sufficient data available for their performance. Among 30 066 liquid-based cervical cancer screening tests results, a group of 332 women was selected with available high-risk types of HPV tests results with 16/18 limited genotyping, liquid-based cytology, DS, and histology results from standardized colposcopy with biopsy. In HPV 16/18+ cases, three triage approaches were retrospectively analyzed. Predictive values for detection of HSIL+ were calculated and number of colposcopies required in each strategy. Both triage models with DS used (reflex cytology followed by DS, and reflex DS alone in all cases) had significantly higher positive predictive value for HSIL+ than strategy with reflex cytology alone (44.2%/45.7% vs. 28.3%; p < 0.0001). In models with DS, less colposcopies were required (95/92 vs. 152) and less colposcopies were needed per HSIL+ detection (2.26/2.19 vs. 3.54). Only one HSIL+ case was missed in both triage models with DS incorporation. p16/Ki67 dual-stain may be an effective, alone or combined with cytology, triage test to detect HSIL+ in patients with major screening abnormalities in primary HPV-based cervical cancer screening. Performing cytology as the first triage test improves the strategy by enabling referrals to expedited treatment in selected cases.

HPV16-miRNAs exert oncogenic effects through enhancers in human cervical cancer.

BACKGROUND: Cervical cancer is a human papillomavirus (HPV)-related disease. HPV type 16 (HPV16), which is the predominant cause of cervical cancer, can encode miRNAs (HPV16-miRNAs). However, the role of HPV16-miRNAs in the pathogenesis of cervical cancer remains unclear. METHODS: Human cervical cancer cell lines SiHa (HPV16-positive) and C33A (HPV-negative), and cervical cancer tissues were collected to investigate the expression levels of two HPV16-miRNAs (HPV16-miR-H1 and HPV16-miR-H6). The overexpression and knockdown of HPV16-miR-H1 and HPV16-miR-H6 were performed using the lentiviral vector system and miRNA inhibitors, respectively. RNA-sequencing (RNA-seq) analysis and H3K27ac chromatin immunoprecipitation and sequencing (CHIP-seq) experiments were utilized to explore the roles of HPV16-miR-H1 and HPV16-miR-H6 facilitated by enhancers. CCK8, EdU, transwell, and wound healing assays were performed to verify the effects of HPV16-miR-H1 and HPV16-miR-H6 on cell proliferation and migration. RESULTS: HPV16-miR-H1 and HPV16-miR-H6 were highly expressed in both SiHa cells and tissue samples from HPV16-positive cervical cancer patients. RNA-seq analysis showed that HPV16-miR-H1 and HPV16-miR-H6 induced the upregulation of numerous tumor progression-associated genes. H3K27ac CHIP-seq experiments further revealed that HPV16-miR-H1 and HPV16-miR-H6 modulated the expression of critical genes by regulating their enhancer activity. The functional study demonstrated that HPV16-miR-H1 and HPV16-miR-H6 increased the migratory capacity of SiHa cells. CONCLUSIONS: Our data shed light on the role of HPV16-encoded miRNAs in cervical cancer, particularly emphasizing their involvement in the miRNA-enhancer-target gene system. This novel regulatory mechanism of HPV16-miRNAs provides new insights and approaches for the development of therapeutic strategies by targeting HPV16-positive cervical cancer.

Biplex quantitative PCR to detect transcriptionally active human papillomavirus 16 from patient saliva.

Head and neck cancers, particularly oropharyngeal cancers (OPC), have been increasingly associated with human papillomavirus (HPV) infections, specifically HPV16. The current methods for HPV16 detection primarily rely on p16 staining or PCR techniques. However, it is important to note the limitations of conventional PCR, as the presence of viral DNA does not always indicate an ongoing viral infection. Moreover, these tests heavily rely on the availability of tissue samples, which can present challenges in certain situations. In this study, we developed a RT-qPCR biplex approach to detect HPV16 oncogenes E6 and E7 RNA in saliva samples from OPC patients. Salivary supernatant was used as the liquid biopsy source. We successfully obtained RNA from salivary supernatant, preserving its integrity as indicated by the detection of several housekeeping genes. Our biplex approach accurately detected E6 and E7 RNA in HPV16-positive cell lines, tissues, and finally in OPC salivary samples. Importantly, the assay specifically targeted HPV16 and not HPV18. This biplexing technique allowed for reduced sample input without compromising specificity. In summary, our approach demonstrates the potential to detect viable HPV16 in saliva from OPC patients. Since the assay measures HPV16 RNA, it provides insights into the transcriptional activity of the virus. This could guide clinical decision-making and treatment planning for individuals with HPV-related OPC.

Human papillomavirus-16 E6-positive cervical cancer attenuated by potent 2-(4-biphenylyl)-N-(1-ethyl-4-piperidinyl) acetamide second-generation analogs with improved binding affinity.

Human papillomavirus (HPV) infection, particularly HPV16, is a major contributor to the development of cervical cancer. Given the urgent need for novel therapeutic strategies targeting HPV-associated cancers, this study focuses on characterizing second-generation analogs of a lead compound, as a potential inhibitor of HPV16-E6. Protein-ligand docking, Gibbs binding free energy estimation, and molecular dynamics simulations were conducted. HPV16-infected SiHa and CaSki cell lines were used. MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay for proliferation and flow cytometry for target inhibition and apoptosis were employed. Computational and cell proliferation analyses revealed that modifications to E6-855, particularly in the piperidinyl group, enhanced binding affinities against HPV16-E6, with E6-272 demonstrating superior binding properties. Molecular dynamics simulations confirmed the stable binding of E6-272 to HPV16-E6, supported by favorable binding energy estimates. E6-272 inhibited the proliferation of SiHa and CaSki cells with GI50 values of 32.56 and 62.09 nM, respectively. The compound reduced HPV16-E6-positive population, while inducing the early and late phase apoptosis in these cells. Structural alterations at the piperidinyl group of E6-855 identified E6-272 as a promising inhibitor of HPV16-E6 with improved efficacy against HPV16-E6. Further experimental validation of E6-272 and its analogs warrant to advance its clinical utility in combating HPV-associated cancers.

HPV16 Genomes: In Silico Analysis of E6 and E7 Oncoproteins in 20 South American Variants.

Background: Human papillomavirus (HPV) is the main risk factor for the development of squamous cell cervical cancer, and E6 oncoprotein and E7 oncoprotein are important components of the viral genome and its oncogenic potential. It is known that different viral variants of HPV16 have different pathology and impact on the development of neoplasia, although few studies have been performed on South American variants. Objective: Therefore, the present study aimed to analyze in silico the genomic diversity of HPV16 in 20 complete genome variants of South America in the National Center for Biotechnology Information (NCBI) database. Methods: We performed a descriptive study to characterize the polymorphic regions of the E6 and E7 genes in HPV16 variants, using software for genomic data and single nucleotide polymorphism (SNP) analysis and others for phylogenetic analysis. Results: The variants analyzed included six SNPs linked to cancer (A131G, G145T, C335T, T350G, C712A, and T732C) and significant variation (798 nucleotide substitutions). Despite this, the variants showed low genetic diversity. Eighteen variants of unclear significance (VUS) were identified, 10 of which were in the coding E6 regions and 8 in the coding E7 regions. The prevalence of lineage D variants is of concern due to their pathology in cervical cancer and requires more research and epidemiological vigilance regarding their prevalence in the population. Conclusion: The data obtained in this study may contribute to future research on South American variants of HPV16, their pathogenicity, and the development of treatments.

Revealing an association between HPV and systemic lupus erythematosus: A bidirectional two-sample Mendelian randomization study.

BACKGROUND: An increasing number of studies have focused on the association between Human papillomavirus (HPV) infection and systemic lupus erythematosus (SLE). However, current evidence is largely based on retrospective studies, which are susceptible to confounding factors and cannot establish causation. METHODS: A bidirectional two-sample Mendelian randomization (MR) design was used to evaluate the causal relationship between HPV and SLE. Mononucleoside polymers (SNPS) with strong evidence for genome-wide association studies (GWAS) were selected from the HPV exposure dataset and used as an instrumental variable (IV) for this study. For the MR Analysis results, the MR-Egger intercept P test, MR-Presso global test, CochranQ test and leave-one test were used for sensitivity analysis. RESULTS: Based on the evidence of MR Analysis, this study finally determined that there was no causal association between HPV16 and HPV18 and SLE. CONCLUSIONS: Possible regulation of HPV infection is not significantly associated with regulation of SLE. These findings provide new insights into the underlying mechanisms of HPV and SLE and need to be validated by further studies.

Does HPV-18 co-infection increase the risk of cervical pathology in individuals with HPV-16?

OBJECTIVE: We aimed to investigate differences between HPV-16 mono- and HPV-16/18 co-infections in terms of cervical dysplasia and invasive cancer. METHODS: This multicentre, retrospective study spanned from December 2017 to December 2020, involving women who visited gynaecological oncology clinics for colposcopy with either HPV-16 or HPV-16/18 positivity. A total of 736 patients, 670 in Group 1 (HPV-16 positivity) and 66 in Group 2 (HPV-16/18 positivity), were compared for the presence of CIN2+ lesions detected by colposcopic biopsy or endocervical curettage (ECC). Exclusions included hysterectomized patients, those with prior gynaecological cancers, and patients with HPV positivity other than types 16 and 18. RESULTS: Among the included patients, 42.4% had a diagnosis of CIN2+ lesions. The cytology results demonstrated abnormal findings in 45.3% in Group 1 and 42.2% in Group 2, with no significant difference between the groups. ECC revealed CIN2+ lesion in 49 (8.7%) patients in group 1, while only 1 (1.7%) patient had CIN2+ lesion in group 2. There was no difference between 2 groups in terms of ECC result (p = 0.052). In group 1, 289 (43.1%) patients had CIN2+ lesion, while 23 (34.8%) patients had CIN2+ lesions in group 2. There was no difference between group 1 and 2 in terms of diagnosis of CIN2+ lesions (p = 0.19). CONCLUSION: This multicentre retrospective study found no significant differences between HPV-16 mono- and HPV-16/18 co-infections regarding cervical pathologies. Larger studies are needed to validate and further explore these findings.

Assessing the Potential of HPV16 E6 Seroprevalence as a Biomarker for Anal Dysplasia and Cancer Screening-A Systematic Review and Meta-Analysis.

Elevated rates of human papillomavirus (HPV)-related anal high-grade squamous intraepithelial lesions (HSIL) and anal cancer (AC) in populations like men who have sex with men (MSM) living with HIV underscore the need for effective screening. While high-resolution anoscopy-guided biopsy is the gold standard, limited provider availability poses a challenge. This has spurred interest in identifying biomarkers for improved AC prevention. Antibodies against HPV16 oncoprotein E6, known as markers for cervical and oropharyngeal cancers, are the focus of the current study. The systematic review and meta-analysis included six studies meeting inclusion criteria, assessing HPV16 E6 seroprevalence in individuals with anal HSIL or AC. A two-step meta-analysis estimated pooled odds ratios and 95% confidence intervals (CI) for HPV16 E6 seroprevalence and HSIL or AC. Pooled prevalence, sensitivity, specificity, and diagnostic odds ratios were also calculated. This meta-analysis revealed a 3.6-fold increased risk of HSIL for HPV16 E6 seropositive individuals, escalating to a 26.1-fold risk increase for AC. Pooled specificity and sensitivity indicated a high specificity (0.99; 95%CI: 0.99, 0.99) but lower sensitivity (0.19; 95%CI: 0.10, 0.34) for HPV16 E6 serostatus as an AC biomarker. In conclusion, while HPV16 E6 seroprevalence demonstrates specificity as a potential biomarker for HPV-related AC, its utility as a standalone screening tool may be limited. Instead, it could serve effectively as a confirmation test, particularly in high-risk populations, alongside other diagnostic methods. Further research is imperative to explore HPV16 E6 seroconversion dynamics and alternative screening algorithms.