Association of human papillomavirus types 16 and 18 E6 proteins with p53

HPV16 CpG Methylation Contributes to Cervical Carcinogenesis by Regulating HPV16 Tumorigenesis-Related Genes

HPV16 CpG methylation is associated with cervical carcinogenesis and the expression of HPV16 tumorigenesis-related genes. However, the genome-wide methylation profile of HPV16 CpG sites during cervical carcinogenesis has not been fully characterized, and the regulatory role of HPV16 CpG methylation in the expression of these genes in cervical carcinogenesis remains unclear. This study aims to comprehensively map HPV16 CpG methylation patterns across different cervical carcinogenesis stages and elucidate its regulatory effect on the expression of HPV16 tumorigenesis-related genes as well as biological alterations in cervical cancer cells. A total of 341 participants diagnosed with various stages of cervical lesions and normal cervix were enrolled to evaluate the associations between HPV16 CpG methylation, expression of HPV16 tumorigenesis-related genes, and cervical carcinogenesis. Demethylation of HPV16 CpG sites in Caski cells using 5-Aza-dC was performed to assess subsequent changes in the expression of HPV16 tumorigenesis-related genes and cellular biological functions. HPV16 hypermethylation was associated with an increased risk of cervical cancer and precancerous lesions. Thirty-six specific CpG sites across various regions of the HPV16 genome exhibited progressively elevated methylation levels correlating with lesion severity. Effects of HPV16 CpGs methylation on cervical carcinogenesis were partially mediated by HPV16 oncoproteins. Demethylation of HPV16 CpGs significantly suppressed HPV16 oncogene expression, promoted apoptosis, and inhibited proliferation, migration, and invasion in cervical cancer cells. This study provides novel insights into the role of HPV16 CpG methylation in cervical carcinogenesis through the modulation of HPV16 oncogenes. This might represent a promising therapeutic strategy for impeding cervical cancer progression.

DARPin-induced reactivation of p53 in HPV-positive cells

Infection of cells with high-risk strains of the human papillomavirus (HPV) causes cancer in various types of epithelial tissue. HPV infections are responsible for ~4.5% of all cancers worldwide. Tumorigenesis is based on the inactivation of key cellular control mechanisms by the viral proteins E6 and E7. The HPV E6 protein interacts with the cellular E3 ligase E6AP, and this complex binds to the p53 DNA-binding domain, which results in degradation of p53. Inhibition of this interaction has the potential to reactivate p53, thus preventing oncogenic transformation. Here we describe the characterization of a designed ankyrin repeat protein that binds to the same site as the HPV E6 protein, thereby displacing the E3 ligase and stabilizing p53. Interaction with the designed ankyrin repeat protein does not affect p53 DNA binding or the crucial MDM2 negative feedback loop but reactivates a p53-dependent transcriptional program in HeLa (HPV18-positive) and SiHa (HPV16-positive) cells, suggesting a potential therapeutic use.

Phase II Trial of Atezolizumab and Bevacizumab for Treatment of HPV-Positive Unresectable or Metastatic Squamous Cell Carcinoma of the Anal Canal

PURPOSE

Anti-PD-L1 antibodies are associated with responses in <25% of patients with metastatic human papillomavirus-associated malignancies. VEGF signaling causes immune evasion and immune suppression within the tumor. We evaluated the anti-PD-L1 antibody atezolizumab and anti-VEGF antibody bevacizumab for patients with unresectable, advanced anal cancer.

PATIENTS AND METHODS

For this phase II study, participants with previously treated, immunotherapy-naïve anal cancer received atezolizumab (1,200 mg) and bevacizumab (15 mg/kg) intravenously every 21 days. Responses were evaluated every 9 weeks (RECIST version 1.1). The primary endpoint was the best radiographic response. Median survival was estimated by Kaplan-Meier and compared for selected biomarkers (including paired pre- and on-treatment biopsies) using a log-rank test.

RESULTS

Among 20 participants, the overall response rate was 11% [95% confidence interval (CI): 1.2-32]. Median progression-free survival and overall survival were 4.1 months (95% CI, 2.6-not assessable) and 11.6 months (95% CI, 9.5-20), respectively. One grade 5 bevacizumab-related bowel perforation occurred. Analyses of 16 paired biopsies linked increases in IFN-γ (P = 0.03) and inflammatory response (P = 0.02) gene expression signatures with prolonged progression-free survival, as did increases in CD3+CD8+PD1+ (P = 0.02) cells and decreases in CD3+FoxP3+ cells (P = 0.04) from 10 paired biopsies with multiplex immunofluorescence. A subgroup of anal cancers characterized by the SBS31 "prior-platinum" signature demonstrated shorter median overall survival (HR, 6.3; 95% CI, 1.2-32; P = 0.01).

CONCLUSIONS

Atezolizumab and bevacizumab demonstrate activity similar to anti-PD-1 antibodies alone for unresectable anal cancer. Our translational data identify undescribed chromosomal and transcriptomic biomarkers associated with survival for metastatic anal cancer. These correlative findings warrant confirmation and further validation in larger, prospective immunotherapy trials for advanced anal cancer.

Hiding in plain sight: NUT carcinoma is an unrecognized subtype of squamous cell carcinoma of the lungs and head and neck

In the past two decades, treatment for non-small-cell lung cancers (NSCLCs) and head and neck squamous cell carcinoma (HNSCC) has advanced considerably, owing largely to the characterization of distinct oncological subtypes, the development of targeted therapies for each subtype and the advent of immunotherapy. Data emerging over the past two decades suggest that NUT carcinoma, a highly aggressive malignancy driven by a NUT fusion oncoprotein and arising in the lungs, head and neck, and rarely in other sites, is a squamous cell carcinoma (SCC) based on transcriptional, histopathological, cell-of-origin and molecular characteristics. NUT carcinoma has an estimated incidence of 1,400 cases per year in the United States, surpassing that of some rare NSCLC and HNSCC subtypes. However, NUT carcinoma is currently not recognized as an SCC of the lungs or head and neck. The orphan classification of NUT carcinoma as a distinct entity leads to a lack of awareness of this malignancy among oncologists and surgeons, despite early diagnosis being crucial for this cancer type with a median survival of only ~6.5 months. Consequently, NUT carcinoma is underdiagnosed and often misdiagnosed, resulting in limited research and progress in developing effective treatments in one of the most aggressive forms of lung and head and neck cancer. With a growing number of targeted agents that can potentially be used to treat NUT carcinoma, improved recognition through reclassification and inclusion of NUT carcinoma as a squamous NSCLC or an HNSCC when arising in these locations will accelerate the development of effective therapies for this disease. Thus, in the Perspective, we propose such a reclassification of NUT carcinoma as an SCC and discuss the supporting evidence.

A Single-Cell Transcriptome Atlas of Epithelial Subpopulations in HPV-Positive and HPV-Negative Head and Neck Cancers

Persistent infection with HPV causes nearly 5% of all cancers worldwide, including cervical and oropharyngeal cancers. Compared to HPV-negative (HPV-) head and neck squamous cell carcinomas (HNSCCs), HPV-positive (HPV+) HNSCCs exhibit a significantly improved treatment response; however, established treatment regimens were largely developed for HPV- disease. Effectively de-escalating therapy and optimizing treatment protocols to minimize toxicity for both HPV+ and HPV- tumors has been variably successful, in part due to the heterogeneity of cellular subpopulations. Single-cell RNA sequencing (scRNAseq) has primarily been used to define immune cell populations rather than the cell type of origin, epithelial cells. To address this, we analyzed published scRNAseq data of HPV+ and HPV- HNSCCs to distinguish epithelial tumor cell populations as a function of HPV status. We identified the transcriptome signatures, ontologies, and candidate biomarkers of newly identified epithelial subpopulations with attention to those that are shared or enriched in HPV+ or HPV- HNSCCs. We hypothesize that distinct epithelial cell populations and reprogramming in HPV- versus HPV+ HNSCC represent important components of the pro-tumor environment. These are described here as a foundation for the identification of new epithelial-cell-specific biomarkers, effectors, and candidate targets for optimizing the treatment of HNSCC.

Pharmacological rescue of mutant p53 triggers spontaneous tumor regression via immune responses

Tumor suppressor p53 is the most frequently mutated protein in cancer, possessing untapped immune-modulating capabilities in anticancer treatment. Here, we investigate the efficacy and underlying mechanisms of pharmacological reactivation of mutant p53 in treating spontaneous tumors in mice. In the p53 R279W (equivalent to the human hotspot R282W) mouse model developing spontaneous tumors, arsenic trioxide (ATO) treatment through drinking water significantly prolongs the survival of mice, dependent on p53-R279W reactivation. Transient regressions of spontaneous T-lymphomas are observed in 70% of the ATO-treated mice, accompanied by interferon (IFN) response. In allograft models, the tumor-suppressive effect of reactivated p53-R279W is detectably reduced in both immunodeficient Rag1-/- and CD8+ T cell-depleted mice. ATO also activates the IFN pathway in human cancer cells harboring various p53 mutations, as well as in primary samples derived from the p53-mutant patient treated with ATO. Together, p53 could serve as an alternative therapeutic target for the development of immunotherapies.

Dys-regulated phosphatidylserine externalization as a cell intrinsic immune escape mechanism in cancer

The negatively charged aminophospholipid, phosphatidylserine (PS), is typically restricted to the inner leaflet of the plasma membrane under normal, healthy physiological conditions. PS is irreversibly externalized during apoptosis, where it serves as a signal for elimination by efferocytosis. PS is also reversibly and transiently externalized during cell activation such as platelet and immune cell activation. These events associated with physiological PS externalization are tightly controlled by the regulated activation of flippases and scramblases. Indeed, improper regulation of PS externalization results in thrombotic diseases such as Scott Syndrome, a defect in coagulation and thrombin production, and in the case of efferocytosis, can result in autoimmunity such as systemic lupus erythematosus (SLE) when PS-mediated apoptosis and efferocytosis fails. The physiological regulation of PS is also perturbed in cancer and during viral infection, whereby PS becomes persistently exposed on the surface of such stressed and diseased cells, which can lead to chronic thrombosis and chronic immune evasion. In this review, we summarize evidence for the dysregulation of PS with a main focus on cancer biology and the pathogenic mechanisms for immune evasion and signaling by PS, as well as the discussion of new therapeutic strategies aimed to target externalized PS. We posit that chronic PS externalization is a universal and agnostic marker for diseased tissues, and in cancer, likely reflects a cell intrinsic form of immune escape. The continued development of new therapeutic strategies for targeting PS also provides rationale for their co-utility as adjuvants and with immune checkpoint therapeutics.

Recent advances in immunotherapy for cervical cancer

Cervical cancer is the third most common malignant tumor in women worldwide in terms of both incidence and mortality. The field of cervical cancer treatment is rapidly evolving, and various combination therapies are being explored to enhance the efficacy of immune checkpoint inhibitors (ICI) and provide new treatment options for patients at different disease stages. Clinical trials involving immune checkpoint inhibitors are now being conducted following a phase 3 trial with cemiplimab, an ICI, which demonstrated a significant improvement in prognosis in advanced or metastatic cervical cancer patients. These trials include monotherapy and combination therapy with other immune therapies, chemotherapy, or radiation therapy. Furthermore, other approaches for controlling tumors via the immune system, such as therapeutic vaccination for specific tumor antigens or immune cell therapy including chimeric antigen receptor (CAR)-T cell therapy and tumor-infiltrating lymphocytes are being investigated. Ongoing trials will continue to illuminate the optimal strategies for combining these therapies and addressing challenges associated with immune checkpoint failure in cervical cancer. Herein, we conducted a review of articles related to immunotherapy for cervical cancer and describe current treatment strategies for cervical cancer via immunotherapy.

The viral landscape in metastatic solid cancers

Here, we analyze the viral landscape in blood and tissue from 4918 metastatic cancer patients across 38 solid cancer types from the Hartwig Medical Foundation (HMF) cohort, the largest pan-cancer study on metastatic cancer. Using a coverage-based filtering approach, we detected 25 unique viral genera across 32 different cancer types, with a total of 747 unique virus-positive tissue samples. We detected 336 virus-positive blood samples across 29 cancer types, dominated by Torque teno virus and Alphatorquevirus. The tissue samples were dominated by Alphapapillomavirus and Roseolovirus. Alphapapillomavirus was significantly enriched in genital, anal, and colorectal cancers and was associated with host mutational signatures and transcriptional programs related to immunity and DNA repair. Host genes with Alphapapillomavirus integration tended to be more highly expressed and samples with HPV integration had higher somatic mutation rates and higher number of extrachromosomal DNA elements. Alphapapillomavirus was also detected in a significant proportion of blood samples from cervix and anal cancers, suggesting a potential blood-based biomarker.

Clinicopathologic and Molecular Characterization of High-Risk Human Papillomavirus-Positive Carcinomas of the Urinary Tract

CONTEXT.—

Human papillomavirus (HPV) is a well-known cause of squamous cell carcinomas of anogenital and oropharyngeal regions, where treatment strategies and prognosis depend on HPV status. The significance of HPV status in tumors arising along the urinary tract is not well established.

OBJECTIVE.—

To provide detailed clinical, morphologic, immunohistochemical, and molecular analysis of HPV+ urinary tract carcinomas (UTCs).

DESIGN.—

We identified and retrospectively examined 12 HPV+ UTCs, confirmed by high-risk HPV in situ hybridization.

RESULTS.—

The HPV+ UTCs originated from the urethra (9) and urinary bladder (3); 5 of 12 (42%) presented with nodal metastasis. On morphology, HPV+ UTCs were predominantly basaloid; well-differentiated squamous areas were focally seen. Available immunohistochemistry (IHC) showed strong staining for p16 (11 of 11), p63 (12 of 12), cytokeratin (CK) 903 (11 of 11), and CK5/6 (11 of 11); variable staining for GATA3 (8 of 12) and CK7 (4 of 11); and rare uroplakin II staining (1 of 12). Molecular analysis revealed the most frequently altered genes: KMT2C (42%), PIK3CA (42%), and KMT2D (25%). In contrast to published conventional urothelial and squamous cell carcinoma molecular data, TERTp mutation was rare (8%), and no TP53 or CDKN2A aberrations were identified. During available follow-up (11 of 12; median, 39 months), 6 patients required treatment for recurrence; ultimately, 1 died of disease, 2 were alive with disease, and 8 had no evidence of disease. Finally, we provide 11 HPV- squamous predominant UTCs for IHC and molecular comparisons; notably, a subset of HPV- UTCs was positive for p16 IHC (27%), making p16 IHC a less-specific surrogate marker for HPV status at this site.

CONCLUSIONS.—

HPV+ UTCs show distinct clinical, morphologic, and molecular characteristics, suggesting important roles for HPV in UTC.

Viral Oncogenesis: Synergistic Role of Genome Integration and Persistence

Persistence is a strategy used by many viruses to evade eradication by the immune system, ensuring their permanence and transmission within the host and optimizing viral fitness. During persistence, viruses can trigger various phenomena, including target organ damage, mainly due to an inflammatory state induced by infection, as well as cell proliferation and/or immortalization. In addition to immune evasion and chronic inflammation, factors contributing to viral persistence include low-level viral replication, the accumulation of viral mutants, and, most importantly, maintenance of the viral genome and reliance on viral oncoprotein production. This review focuses on the process of genome integration, which may occur at different stages of infection (e.g., HBV), during the chronic phase of infection (e.g., HPV, EBV), or as an essential part of the viral life cycle, as seen in retroviruses (HIV, HTLV-1). It also explores the close relationship between integration, persistence, and oncogenesis. Several models have been proposed to describe the genome integration process, including non-homologous recombination, looping, and microhomology models. Integration can occur either randomly or at specific genomic sites, often leading to genome destabilization. In some cases, integration results in the loss of genomic regions or impairs the regulation of oncogene and/or oncosuppressor expression, contributing to tumor development.

The Natural History of Cervical Cancer and the Case for MicroRNAs: Is Human Papillomavirus Infection the Whole Story?

MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that negatively regulate gene expression. MiRNAs regulate fundamental biological processes and have significant roles in several pathologies, including cancer. Cervical cancer is the best-known example of a widespread human malignancy with a demonstrated viral etiology. Infection with high-risk human papillomavirus (hrHPV) has been shown to be a causative factor for cervical carcinogenesis. Despite the occurrence of prophylactic vaccines, highly sensitive HPV diagnostics, and innovative new therapies, cervical cancer remains a main cause of death in developing countries. The relationship between hrHPV infection and cervical cancer depends on the integration of viral DNA to the host genome, disrupting the viral regulator E2 and the continuous production of the viral E6 and E7 proteins, which are necessary to acquire and maintain a transformed phenotype but insufficient for malignant cervical carcinogenesis. Lately, miRNAs, the tumor microenvironment, and immune evasion have been found to be major players in cervical carcinogenesis after hrHPV infection. Many miRNAs have been widely reported as deregulated in cervical cancer. Here, the relevance of miRNA in HPV-mediated transformation is critically reviewed in the context of the natural history of hrHPV infection and cervical cancer.

Why HPV16? Why, now, HPV42? How the discovery of HPV42 in rare cancers provides an opportunity to challenge our understanding about the transition between health and disease for common members of the healthy microbiota

In 2022, a bioinformatic, agnostic approach identified HPV42 as causative agent of a rare cancer, later confirmed experimentally. This unexpected association offers an opportunity to reconsider our understanding about papillomavirus infections and cancers. We have expanded our knowledge about the diversity of papillomaviruses and the diseases they cause. Yet, we still lack answers to fundamental questions, such as what makes HPV16 different from the closely related HPV31 or HPV33; or why the very divergent HPV13 and HPV32 cause focal epithelial hyperplasia, while HPV6 or HPV42 do not, despite their evolutionary relatedness. Certain members of the healthy skin microbiota are associated to rare clinical conditions. We propose that a focus on cellular phenotypes, most often transient and influenced by intrinsic and extrinsic factors, may help understand the continuum between health and disease. A conceptual switch is required towards an interpretation of biology as a diversity of states connected by transition probabilities, rather than quasi-deterministic programs. Under this perspective, papillomaviruses may only trigger malignant transformation when specific viral genotypes interact with precise cellular states. Drawing on Canguilhem's concepts of normal and pathological, we suggest that understanding the transition between fluid cellular states can illuminate how commensal-like infections transition from benign to malignant.

What are the essential determinants of human papillomavirus carcinogenesis?

Human papillomavirus (HPV) infection is the leading viral cause of cancer. Over the past several decades, research on HPVs has provided remarkable insight into human cell biology and into the pathology of viral and non-viral cancers. The HPV E6 and E7 proteins engage host cellular proteins to establish an environment in infected cells that is conducive to virus replication. They rewire host cell signaling pathways to promote proliferation, inhibit differentiation, and limit cell death. The activity of the "high-risk" HPV E6 and E7 proteins is so potent that their dysregulated expression is sufficient to drive the initiation and maintenance of HPV-associated cancers. Consequently, intensive research efforts have aimed to identify the host cell targets of E6 and E7, in part with the idea that some or all of the virus-host interactions would be essential cancer drivers. These efforts have identified a large number of potential binding partners of each oncoprotein. However, over the same time period, parallel research has revealed that a relatively small number of genetic mutations drive carcinogenesis in most non-viral cancers. We therefore propose that a high-priority goal is to identify which of the many targets of E6 and E7 are critical drivers of HPV carcinogenesis. By identifying the cancer-driving targets of E6 and E7, it should be possible to better understand the distinct roles of other targets, perhaps in the viral life cycle, and to focus efforts to develop anti-cancer therapies on the subset of virus-host interactions for which therapeutic intervention would have the greatest impact.

HPV-YAP1 oncogenic alliance drives malignant transformation of fallopian tube epithelial cells

High grade serous ovarian carcinoma (HGSOC) is the most common and aggressive ovarian malignancy. Accumulating evidence indicates that HGSOC may originate from human fallopian tube epithelial cells (FTECs), although the exact pathogen(s) and/or molecular mechanism underlying the malignant transformation of FTECs is unclear. Here we show that human papillomavirus (HPV), which could reach FTECs via retrograde menstruation or sperm-carrying, interacts with the yes-associated protein 1 (YAP1) to drive the malignant transformation of FTECs. HPV prevents FTECs from natural replicative and YAP1-induced senescence, thereby promoting YAP1-induced malignant transformation of FTECs. HPV also stimulates proliferation and drives metastasis of YAP1-transformed FTECs. YAP1, in turn, stimulates the expression of the putative HPV receptors and suppresses the innate immune system to facilitate HPV acquisition. These findings provide critical clues for developing new strategies to prevent and treat HGSOC.

Chromosomal instability increases radiation sensitivity

Continuous chromosome missegregation over successive mitotic divisions, known as chromosomal instability (CIN), is common in cancer. Increasing CIN above a maximally tolerated threshold leads to cell death due to loss of essential chromosomes. Here, we show in two tissue contexts that otherwise isogenic cancer cells with higher levels of CIN are more sensitive to ionizing radiation, which itself induces CIN. CIN also sensitizes HPV-positive and HPV-negative head and neck cancer patient derived xenograft (PDX) tumors to radiation. Moreover, laryngeal cancers with higher CIN prior to treatment show improved response to radiation therapy. In addition, we reveal a novel mechanism of radiosensitization by docetaxel, a microtubule stabilizing drug commonly used in combination with radiation. Docetaxel causes cell death by inducing CIN due to abnormal multipolar spindles rather than causing mitotic arrest, as previously assumed. Docetaxel-induced CIN, rather than mitotic arrest, is responsible for the enhanced radiation sensitivity observed in vitro and in vivo, challenging the mechanistic dogma of the last 40 years. These results implicate CIN as a potential biomarker and inducer of radiation response, which could provide valuable cancer therapeutic opportunities.

Statement of Significance

Cancer cells and laryngeal tumors with higher chromosome missegregation rates are more sensitive to radiation therapy, supporting chromosomal instability as a promising biomarker of radiation response.

Clinical outcomes and prognostic factors of concurrent chemoradiotherapy for anal squamous cell carcinoma in Japan

BACKGROUND

Concurrent chemoradiotherapy (CCRT) is the standard treatment for locoregional anal squamous cell carcinoma (ASCC) in western countries. However, there have been few reports on the clinical outcomes of CCRT in Japan. This study aimed to evaluate the clinical outcomes of CCRT, prognostic factors, and the clinical impact of programmed cell death-ligand 1 (PD-L1) expression of ASCC in Japan.

METHODS

Patients with locoregional ASCC were enrolled between 2007 and 2017. All patients received CCRT consisting of ≥ 45 Gy of radiation, 5-fluorouracil, and mitomycin C. Disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were estimated. Expression of p16 and PD-L1 were assessed by immunohistochemical staining (IHC).

RESULTS

This study included 36 patients, of whom 30 (83.3%) were female. Among the participants, 32 (88.9%) achieved complete clinical remission, while six (16.7%) experienced recurrence. The five-year DFS and five-year OS were 72.2% and 84.7%, respectively. Grades ≥ 3 serious AEs included neutropenia in 10 (27.7%) and perianal dermatitis in eight (22.2%). In a univariate analysis, male sex, lymph node metastasis, and large tumor size were significantly associated with worse outcome. In a multivariate analysis, tumor size was an independent factor associated with short DFS. Of the 30 patients whose biopsy specimens were available for IHC, 29 (96.7%) were positive for p16, and 13 (43.3%) were positive for PD-L1. However, PD-L1 expression did not show any clinical impact.

CONCLUSIONS

The comparative etiology, clinical outcomes, and prognostic factors of CCRT observed in Japanese patients with locoregional ASCC were consistent with western data.

Targeting WEE1 Kinase in Gynecological Malignancies

WEE1 kinase is involved in the G2/M cell cycle checkpoint control and DNA damage repair. A functional G2/M checkpoint is crucial for DNA repair in cancer cells with p53 mutations since they lack a functional G1/S checkpoint. Targeted inhibition of WEE1 kinase may cause tumor cell apoptosis, primarily, in the p53-deficient tumor, via bypassing the G2/M checkpoint without properly repairing DNA damage, resulting in genome instability and chromosomal deletion. This review aims to provide a comprehensive overview of the biological role of WEE1 kinase and the potential of WEE1 inhibitor (WEE1i) for treating gynecological malignancies. We conducted a thorough literature search from 2001 to September 2023 in prominent databases such as PubMed, Scopus, and Cochrane, utilizing appropriate keywords of WEE1i and gynecologic oncology. WEE1i has been shown to inhibit tumor activity and enhance the sensitivity of chemotherapy or radiotherapy in preclinical models, particularly in p53-mutated gynecologic cancer models, although not exclusively. Recently, WEE1i alone or combined with genotoxic agents has confirmed its efficacy and safety in Phase I/II gynecological malignancies clinical trials. Furthermore, it has become increasingly clear that other inhibitors of DNA damage pathways show synthetic lethality with WEE1i, and WEE1 modulates therapeutic immune responses, providing a rationale for the combination of WEE1i and immune checkpoint blockade. In this review, we summarize the biological function of WEE1 kinase, development of WEE1i, and outline the preclinical and clinical data available on the investigation of WEE1i for treating gynecologic malignancies.

Management for persistent HPV infection and cervical lesions among women infected with HIV: a retrospective observational cohort study

BACKGROUND

Early diagnosis and treatment of HPV persistent infection and cervical intraepithelial neoplasia, which have yet to be thoroughly characterized in Guangxi, Southwestern China, are the key preventative measures for the development of cervical cancer in women, particularly in HIV-infected women.

METHODS

A retrospective study of 181 patients with HPV infection or cervical intraepithelial neoplasia who received surgical excision of lesions and were prospectively enrolled at the Fourth People's Hospital of Nanning between January 2018 and February 2023 was performed. HPV-infected patients were divided into two subgroups: HIV-infected and HIV/HPV-coinfected patients and compare differences between these groups.

RESULTS

HPV16, 18, 52, and 58 were the most prevalent HPV genotypes. High-risk HPV was significantly co-infected with multiple genotypes (P = 0.0332). HIV-infected women were predisposed to HPV infection (P < 0.0001), and the development of cervical cancer at a young age (P = 0.0336) compared to HIV-uninfected women and the loop electrosurgical excision procedure (P = 0.0480) is preferred for the treatment.

CONCLUSIONS

HIV infection may increase HPV prevalence and lead to cervical cancer development at a young age. The loop electrosurgical excision procedure is an efficient evaluation and treatment strategy for HIV-infected women suffering from cervical intraepithelial neoplasia.

Increased human papillomavirus viral load is correlated to higher severity of cervical disease and poorer clinical outcome: A systematic review

Cervical cancer is the fourth most common cancer in women worldwide and is caused by persistent infection with high-risk types of human papillomavirus (HPV). HPV viral load, the amount of HPV DNA in a sample, has been suggested to correlate with cervical disease severity, and with clinical outcome of cervical cancer. In this systematic review, we searched three databases (EMBASE, PubMed, Web of Science) to examine the current evidence on the association between HPV viral load in cervical samples and disease severity, as well as clinical outcome. After exclusion of articles not on HPV, cervical cancer, or containing clinical outcomes, 85 original studies involving 173 746 women were included. The vast majority (73/85 = 85.9%) reported that a higher viral load was correlated with higher disease severity or worse clinical outcome. Several studies reported either no correlation (3/85 = 3.5%), or the opposite correlation (9/85 = 10.6%); possible reasons being different categorization of HPV viral load levels, or the use of specific sampling methods. Despite variations in study design and populations, the above findings suggest that HPV viral load is correlated to clinical outcome, and may become an important biomarker for treatment selection and response monitoring for cervical cancer.

Allelic loss of HLA class I facilitates evasion from immune surveillance in cervical intraepithelial neoplasia

Loss of heterozygosity (LOH) has been reported to occur in HLA regions in cervical intraepithelial neoplasia (CIN) and cervical cancer. However, the details of how this is related to the progression of CIN have been unclear. In this study, we examined the human papillomavirus (HPV) antigen-presenting capacity of people with CIN and the significance of LOH of HLA class I in the progression of CIN. It was shown that differences in antigen-presenting capacity among each case depended on HLA types, not HPV genotypes. Focusing on the HLA type, there was a positive correlation between antigen-presenting capacity against HPV and the frequency of allelic loss. Furthermore, the lost HLA-B alleles had a higher HPV antigen-presenting capacity than intact alleles. In addition, frequency of LOH of HLA class I was significantly higher in advanced CIN (CIN2-3) than in cervicitis or early-stage CIN (CIN1): around half of CIN2-3 had LOH of any HLA class I. Moreover, the antigen-presenting capacity against E5, which is the HPV proteins that facilitate viral escape from this immune surveillance by suppressing HLA class I expression, had the most significant impact on the LOH in HLA-B. This study suggests that HPV evades immune surveillance mechanisms when host cells lose the capacity for antigen presentation by HLA class I molecules, resulting in long-term infection and progression to advanced lesions.

Structure of the p53 degradation complex from HPV16

Human papillomavirus (HPV) is a significant contributor to the global cancer burden, and its carcinogenic activity is facilitated in part by the HPV early protein 6 (E6), which interacts with the E3-ligase E6AP, also known as UBE3A, to promote degradation of the tumor suppressor, p53. In this study, we present a single-particle cryoEM structure of the full-length E6AP protein in complex with HPV16 E6 (16E6) and p53, determined at a resolution of ~3.3 Å. Our structure reveals extensive protein-protein interactions between 16E6 and E6AP, explaining their picomolar binding affinity. These findings shed light on the molecular basis of the ternary complex, which has been pursued as a potential therapeutic target for HPV-driven cervical, anal, and oropharyngeal cancers over the last two decades. Understanding the structural and mechanistic underpinnings of this complex is crucial for developing effective therapies to combat HPV-induced cancers. Our findings may help to explain why previous attempts to disrupt this complex have failed to generate therapeutic modalities and suggest that current strategies should be reevaluated.

The Hallmarks of Cervical Cancer: Molecular Mechanisms Induced by Human Papillomavirus

Human papillomaviruses (HPVs) and, specifically, high-risk HPVs (HR-HPVs) are identified as necessary factors in the development of cancer of the lower genital tract, with CaCU standing out as the most prevalent tumor. This review summarizes ten mechanisms activated by HR-HPVs during cervical carcinogenesis, which are broadly associated with at least seven of the fourteen distinctive physiological capacities of cancer in the newly established model by Hanahan in 2022. These mechanisms involve infection by human papillomavirus, cellular tropism, genetic predisposition to uterine cervical cancer (CaCU), viral load, viral physical state, regulation of epigenetic mechanisms, loss of function of the E2 protein, deregulated expression of E6/E7 oncogenes, regulation of host cell protein function, and acquisition of the mesenchymal phenotype.

High-grade vulvar intraepithelial neoplasia: comprehensive characterization and long-term vulvar carcinoma risk

AIMS

Adequate diagnosis of human papillomavirus (HPV)-associated high-grade squamous intraepithelial lesion (HSIL) and HPV-independent vulvar intraepithelial neoplasia (VIN) is essential but can be challenging. We comprehensively characterized a large population-based series of vulvar lesions, originally reported as high-grade VIN, and assessed the cancer risk.

METHODS AND RESULTS

Baseline high-grade VIN of 751 patients were categorized by histopathological reassessment, integrating the results of immunohistochemistry (p16INK4a , p53, Ki-67) and HPV DNA testing. Integrated analyses resulted in 88.4% HPV-associated lesions (77.0% HSIL, 10.9% low-grade SIL [LSIL], and 0.4% vulvar squamous cell carcinoma [VSCC]), 10.9% HPV-independent lesions (6.1% HPV-independent VIN, 4.7% nondysplastic lesions, and 0.1% VSCC) and 1.1% inconclusive lesions. HSIL demonstrated p16INK4a block-positivity in 99.0%, increased Ki-67 in ≥2/3rd of the epithelium in 93.6%, and HPV positivity in 99.6%. In HSIL, a p53 wildtype mid-epithelial staining pattern was common (51.6%) while this was not observed in HPV-independent lesions. HPV-independent VIN harboured mutant p53 patterns in 65.2% and showed a wide morphological spectrum, ranging from differentiated to nondifferentiated ('HPV-associated-like', in 41.3%). Kaplan-Meier analyses showed a 10-year cancer risk of 8.0% in HPV-associated HSIL, 67.4% in HPV-independent VIN/p53mutant, and 27.8% in HPV-independent VIN/p53wildtype. Strikingly, the 10-year cancer risk was 73.3% in HPV-independent VIN with nondifferentiated ('HPV-associated-like') morphology.

CONCLUSION

Immunohistochemistry by p16INK4a and p53 is highly recommended for optimal categorization into HPV-associated and HPV-independent VIN, which is of utmost importance given the different cancer risk. The high cancer risk of HPV-independent VIN underscores the need for surgical treatment and close follow-up, especially in case of a p53 mutant pattern and/or nondifferentiated morphology.

MmuPV1 E6 induces cell proliferation and other hallmarks of cancer

IMPORTANCE

The Mus musculus papillomavirus 1 (MmuPV1) E6 and E7 proteins are required for MmuPV1-induced disease. Our understanding of the activities of MmuPV1 E6 has been based on affinity purification/mass spectrometry studies where cellular interacting partners of MmuPV1 E6 were identified, and these studies revealed that MmuPV1 E6 can inhibit keratinocyte differentiation through multiple mechanisms. We report that MmuPV1 E6 encodes additional activities including the induction of proliferation, resistance to density-mediated growth arrest, and decreased dependence on exogenous growth factors. Proteomic and transcriptomic analyses provided evidence that MmuPV1 E6 increases the expression and steady state levels of a number of cellular proteins that promote cellular proliferation and other hallmarks of cancer. These results indicate that MmuPV1 E6 is a major driver of MmuPV1-induced pathogenesis.

Deciphering the role of HPV-mediated metabolic regulation in shaping the tumor microenvironment and its implications for immunotherapy in HNSCC

Head and neck squamous cell carcinoma (HNSCC), as a complex and variable malignancy, poses a significant threat to human health. Since the intricate association between HPV and HNSCC emerged, its role within the TME has garnered extensive attention. HPV+HNSCC exhibits distinct immunological characteristics within the TME, intricately intertwined with mechanisms of immune evasion. HPV employs multifaceted pathways to intervene in metabolic regulation within the TME, exerting influence over immune cell functionality and neoplastic cell genesis. Furthermore, the heightened immune reactivity exhibited by HPV+HNSCC within the TME augments responses to immune interventions such as immune checkpoint inhibitors. Therefore, amidst the current limitations of therapeutic approaches, immunotherapy stands as a promising strategy to overcome the conventional confines of treating HNSCC. This article comprehensively outlines the impact of HPV on the inception and progression of HNSCC while discussing the amalgamation of metabolic regulation within the TME and immunotherapeutic strategies. By intervening in the reciprocal interactions between HPV and HNSCC within the TME, the potential to modulate the efficacy of immune-based treatments becomes evident. Concurrently, a synthesis of pertinent biomarker development is summarized. Such endeavors hold paramount significance for personalized therapeutic approaches and the more effective management of HNSCC patients.

Assessment and clinicopathological correlation of p16 expression in cervical squamous cell carcinoma of Indian population: Diagnostic implications

BACKGROUND

Our aim was to assess the p16 expression in normal cervical epithelium and cervical lesions and how it correlated with HPV oncoprotein E7 and other etiological parameters of cervical cancer.

METHODS

For this purpose, we analyzed protein expression of p16 and E7 oncoprotein in total 20 normal cervical epithelium tissue (as control) and 62 cervical lesions. Next, the result was correlated with different clinico-pathological parameters.

RESULTS

Out of 62 cases of cervical lesions, we found around 75%-100% of the cervical lesion samples exhibited E7 nuclear protein expression, whereas around 33.33%-75% samples were p16 positive. On the other hand, p16 expression showed strong association with E7 oncoprotein and other clinico-pathological parameters (like high parity, early age of sextual debut) in the same set of samples of our study.

CONCLUSION

We concluded that overexpression of p16 is very practical and can be readily implemented in most diagnostic pathology laboratories.

Analysis of somatic mutations and key driving factors of cervical cancer progression

We investigated the somatic mutations and key driving factors of cervical cancer by whole exome sequencing . We found 22,183 somatic single nucleotide variations (SNVs) in 52 paired samples. Somatic SNVs in cervical cancer were significantly higher than those in high-grade intraepithelial lesion and low-grade squamous intraepithelial lesion groups (P < 0.05). C → T/G accounted for 44.12% of base substitution. Copy number variation (false discovery rate < 0.05) was found in 57 chromosome regions. The three regions with significant differences between cervical cancer and non-cervical cancer groups were 1q21.1, 3q26.33, and 13q33.1, covering genes related to tumor proliferation, differentiation, and apoptosis. The frequency of human papillomavirus (HPV) insertion/integration and the number of "tCw" mutations in the cervical cancer group were significantly higher than those in the non-cervical cancer group (P < 0.05). The total number of mutations was positively correlated with the number of "tCw" mutations (R 2 = 0.7967). HPV insertion/integration (OR = 2.302, CI = 1.523-3.589, P = 0.0005), APOBEC enrichment (OR = 17.875, CI = 2.117-150.937, P = 0.001), and HLA-B*39 in HLA-I (OR = 6.435, CI = 0.823-48.919, P = 0.0042) were risk factors for cervical cancer, while HLA-DQB1*05 in HLA-II was a protective factor (OR = 0.426, CI = 0.197-0.910, P = 0.032). Conclusively, HPV insertion/integration, APOBEC mutagenesis, and HLA polymorphisms are high-risk factors for cervical cancer and may be causes of genome instability and somatic mutations. This study provides experimental data for revealing the molecular mechanism of cervical cancer.

SNORD6 promotes cervical cancer progression by accelerating E6-mediated p53 degradation

Small nucleolar RNAs (snoRNAs) are a class of non-coding RNAs widely distributed in eukaryotic nucleoli. In recent years, studies have revealed that snoRNAs can also participate in the occurrence and development of malignant tumors through different pathways. Cervical cancer is one of the most common malignant tumors of the female reproductive system, and the high-risk HPV virus infection is its main pathogenic mechanism. However, the outcomes in different patients with malignant tumors vary, indicating that other factors might affect the pathogenic process of cervical cancer. In this study, we screened the poor prognosis indicator SNORD6 from the TCGA database to find the snoRNA that affects the disease outcome during the pathogenesis of cervical cancer. We discovered that SNORD6 expression in cervical cancer tissues was higher than that in normal cervical tissues. Cell phenotype experiments revealed that the knockdown of SNORD6 retarded cell proliferation and plate clone formation. Furthermore, G1-S phase cell cycle arrest was induced, DNA synthesis was decreased, cell migration and invasion were reduced, while the level of apoptosis increased, whereas the opposite results were obtained after SNORD6 overexpression. Moreover, after intratumoral injection of ASO-SNORD6, the tumor growth rate slowed down, and the tumor volume decreased compared with the control group. In the mechanism study, we found that SNORD6 concurrently acted as a binding "hub" to promote the formation of the tumor suppressor protein p53 degradation complex E6-E6AP-p53. This reaction enhanced the ubiquitination and degradation of p53, thus influenced the regulation of p53 activities in the cell cycle and apoptosis. This study preliminarily clarified the biological role and specific mechanism of SNORD6 in the occurrence of cervical cancer, broadening the basic theoretical research of ovarian cancer and may provide a new perspective on the diagnosis and treatment of cervical cancer.

Virus usurps alternative splicing to clear the decks for infection

Since invasion, there will be a tug-of-war between host and virus to scramble cellular resources, for either restraining or facilitating infection. Alternative splicing (AS) is a conserved and critical mechanism of processing pre-mRNA into mRNAs to increase protein diversity in eukaryotes. Notably, this kind of post-transcriptional regulatory mechanism has gained appreciation since it is widely involved in virus infection. Here, we highlight the important roles of AS in regulating viral protein expression and how virus in turn hijacks AS to antagonize host immune response. This review will widen the understandings of host-virus interactions, be meaningful to innovatively elucidate viral pathogenesis, and provide novel targets for developing antiviral drugs in the future.

Extrachromosomal Amplification of Human Papillomavirus Episomes Is a Mechanism of Cervical Carcinogenesis

SIGNIFICANCE

Multimers of the HPV genome are generated in cervical tumors replicating as extrachromosomal episomes, which is associated with deletion and rearrangement of the HPV genome and provides a mechanism for oncogenesis without integration.

Human papillomavirus E5 suppresses immunity via inhibition of the immunoproteasome and STING pathway

The role that human papillomavirus (HPV) oncogenes play in suppressing responses to immunotherapy in cancer deserves further investigation. In particular, the effects of HPV E5 remain poorly understood relative to E6 and E7. Here, we demonstrate that HPV E5 is a negative regulator of anti-viral interferon (IFN) response pathways, antigen processing, and antigen presentation. Using head and neck cancer as a model, we identify that E5 decreases expression and function of the immunoproteasome and that the immunoproteasome, but not the constitutive proteasome, is associated with improved overall survival in patients. Moreover, immunopeptidome analysis reveals that HPV E5 restricts the repertoire of antigens presented on the cell surface, likely contributing to immune escape. Mechanistically, we discover a direct interaction between E5 and stimulator of interferon genes (STING), which suppresses downstream IFN signaling. Taken together, these findings identify a powerful molecular mechanism by which HPV E5 limits immune detection and mediates resistance to immunotherapy.

Gene Expression Profiles of Methyltransferases and Demethylases Associated with Metastasis, Tumor Invasion, CpG73 Methylation, and HPV Status in Head and Neck Squamous Cell Carcinoma

Epigenetic studies on the role of DNA-modifying enzymes in HNSCC tumorigenesis have focused on a single enzyme or a group of enzymes. To acquire a more comprehensive insight into the expression profile of methyltransferases and demethylases, in the present study, we examined the mRNA expression of the DNA methyltransferases DNMT1, DNMT3A, and DNMT3B, the DNA demethylases TET1, TET2, TET3, and TDG, and the RNA methyltransferase TRDMT1 by RT-qPCR in paired tumor-normal tissue samples from HNSCC patients. We characterized their expression patterns in relation to regional lymph node metastasis, invasion, HPV16 infection, and CpG73 methylation. Here, we show that tumors with regional lymph node metastases (pN+) exhibited decreased expression of DNMT1, 3A and 3B, and TET1 and 3 compared to non-metastatic tumors (pN0), suggesting that metastasis requires a distinct expression profile of DNA methyltransferases/demethylases in solid tumors. Furthermore, we identified the effect of perivascular invasion and HPV16 on DNMT3B expression in HNSCC. Finally, the expression of TET2 and TDG was inversely correlated with the hypermethylation of CpG73, which has previously been associated with poorer survival in HNSCC. Our study further confirms the importance of DNA methyltransferases and demethylases as potential prognostic biomarkers as well as molecular therapeutic targets for HNSCC.

Interaction between Human Papillomavirus-Encoded E6 Protein and AurB Induces Cell Immortalization and Proliferation-A Potential Target of Intervention

The human papillomavirus E6 and E7 oncoproteins interact with a different subset of host proteins, leading to dysregulation of the apoptotic, cell cycle, and signaling pathways. In this study, we identified, for the first time, that Aurora kinase B (AurB) is a bona fide interacting partner of E6. We systematically characterized the AurB-E6 complex formation and its consequences in carcinogenesis using a series of in vitro and cell-based assays. We also assessed the efficacy of Aurora kinase inhibitors in halting HPV-mediated carcinogenesis using in vitro and in vivo models. We showed that AurB activity was elevated in HPV-positive cells, and this correlated positively with the E6 protein level. E6 interacted directly with AurB in the nucleus or mitotic cells. A previously unidentified region of E6, located upstream of C-terminal E6-PBM, was important for AurB-E6 complex formation. AurB-E6 complex led to reduced AurB kinase activity. However, the AurB-E6 complex increased the hTERT protein level and its telomerase activity. On the other hand, AurB inhibition led to the inhibition of telomerase activity, cell proliferation, and tumor formation, even though this may occur in an HPV-independent manner. In summary, this study dissected the molecular mechanism of how E6 recruits AurB to induce cell immortalization and proliferation, leading to the eventual cancer development. Our findings revealed that the treatment of AZD1152 exerted a non-specific anti-tumor effect. Hence, a continuous effort to seek a specific and selective inhibitor that can halt HPV-mediated carcinogenesis should be warranted.

Homogenous TP53mut-associated tumor biology across mutation and cancer types revealed by transcriptome analysis

TP53 is the most frequently mutated gene in human cancer. While no TP53-targeting drugs have been approved in the USA or Europe so far, preclinical and clinical studies are underway to investigate targeting of specific or all TP53 mutations, for example, by restoration of the functionality of mutated TP53 (TP53mut) or protecting wildtype TP53 (TP53wt) from negative regulation. We performed a comprehensive mRNA expression analysis in 24 cancer types of TCGA to extract (i) a consensus expression signature shared across TP53 mutation types and cancer types, (ii) differential gene expression patterns between tumors harboring different TP53 mutation types such as loss of function, gain of function or dominant-negative mutations, and (iii) cancer-type-specific patterns of gene expression and immune infiltration. Analysis of mutational hotspots revealed both similarities across cancer types and cancer type-specific hotspots. Underlying ubiquitous and cancer type-specific mutational processes with the associated mutational signatures contributed to explaining this observation. Virtually no genes were differentially expressed between tumors harboring different TP53 mutation types, while hundreds of genes were over- and underexpressed in TP53mut compared to TP53wt tumors. A consensus list included 178 genes that were overexpressed and 32 genes that were underexpressed in the TP53mut tumors of at least 16 of the investigated 24 cancer types. In an association analysis of immune infiltration with TP53 mutations in 32 cancer subtypes, decreased immune infiltration was observed in six subtypes, increased infiltration in two subtypes, a mixed pattern of decreased and increased immune cell populations in four subtypes, while immune infiltration was not associated with TP53 status in 20 subtypes. The analysis of a large cohort of human tumors complements results from experimental studies and supports the view that TP53 mutations should be further evaluated as predictive markers for immunotherapy and targeted therapies.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

MmuPV1 E7's interaction with PTPN14 delays Epithelial differentiation and contributes to virus-induced skin disease

Human papillomaviruses (HPVs) contribute to approximately 5% of all human cancers. Species-specific barriers limit the ability to study HPV pathogenesis in animal models. Murine papillomavirus (MmuPV1) provides a powerful tool to study the roles of papillomavirus genes in pathogenesis arising from a natural infection. We previously identified Protein Tyrosine Phosphatase Non-Receptor Type 14 (PTPN14), a tumor suppressor targeted by HPV E7 proteins, as a putative cellular target of MmuPV1 E7. Here, we confirmed the MmuPV1 E7-PTPN14 interaction. Based on the published structure of the HPV18 E7/PTPN14 complex, we generated a MmuPV1 E7 mutant, E7K81S, that was defective for binding PTPN14. Wild-type (WT) and E7K81S mutant viral genomes replicated as extrachromosomal circular DNAs to comparable levels in mouse keratinocytes. E7K81S mutant virus (E7K81S MmuPV1) was generated and used to infect FoxN/Nude mice. E7K81S MmuPV1 caused neoplastic lesions at a frequency similar to that of WT MmuPV1, but the lesions arose later and were smaller than WT-induced lesions. The E7K81S MmuPV1-induced lesions also had a trend towards a less severe grade of neoplastic disease. In the lesions, E7K81S MmuPV1 supported the late (productive) stage of the viral life cycle and promoted E2F activity and cellular DNA synthesis in suprabasal epithelial cells to similar degrees as WT MmuPV1. There was a similar frequency of lateral spread of infections among mice infected with E7K81S or WT MmuPV1. Compared to WT MmuPV1-induced lesions, E7K81S MmuPV1-induced lesions had a significant expansion of cells expressing differentiation markers, Keratin 10 and Involucrin. We conclude that an intact PTPN14 binding site is necessary for MmuPV1 E7's ability to contribute to papillomavirus-induced pathogenesis and this correlates with MmuPV1 E7 causing a delay in epithelial differentiation, which is a hallmark of papillomavirus-induced neoplasia.

Novel canonical and non-canonical viral antigens extend current targets for immunotherapy of HPV-driven cervical cancer

Current immunotherapeutic approaches for human papillomavirus (HPV)-driven cervical cancer target the viral oncogenes E6 and E7. We report viral canonical and alternative reading frame (ARF)-derived sequences presented on cervical tumor cells, including antigens encoded by the conserved viral gene E1. We confirm immunogenicity of the identified viral peptides in HPV-positive women, and women with cervical intraepithelial neoplasia. We observe consistent transcription of the E1, E6, and E7 genes in 10 primary cervical tumor resections from the four most common high-risk HPV subtypes (HPV16, 18, 31, and 45), suggesting the suitability of E1 as therapeutic target. We finally confirm HLA presentation of canonical peptides derived from E6 and E7, and ARF-derived viral peptides from a reverse-strand transcript spanning the HPV E1 and E2 genes in primary human cervical tumor tissue. Our results extend currently known viral immunotherapeutic targets in cervical cancer and highlight E1 as an important cervical cancer antigen.

E6-Encoded by Cancer-Causing Human Papillomavirus Interacts with Aurora Kinase A To Promote HPV-Mediated Carcinogenesis

The expression of human papillomavirus (HPV) oncoproteins perturbed multiple cellular events of the host cells, leading to the formation of cancer phenotypes. Our current and previous studies indicated that Aurora kinase A (AurA), a mitotic regulator that is often aberrantly expressed in human cancers, is preferentially bound to E6-encoded by cancer-causing HPV. AurA is believed to be important for the proliferation and survival of HPV-positive cells. Nonetheless, the interaction between AurA and E6, and the mechanism of how this association is involved in carcinogenesis, have not been elucidated clearly. Hence, we performed a series of biochemical assays to characterize the AurA-E6 association and complex formation. We found the C-terminus of E6, upstream of the PDZ binding motif of E6, is important to forming the AurA-E6 complex in the nucleus. We also showed that the expression level of E6 corresponded positively with AurA expression. Meanwhile, the functional consequences of the AurA-E6 association to AurA kinase function and host cellular events were also delineated. Intriguingly, we revealed that AurA-E6 association regulated the expression of cyclin E and phosphor-Histone H3, which are involved in G1/S and mitotic phases of the cell cycle, respectively. Depletion of AurA also reduced the invasive ability of HPV-positive cells. AurA inhibition may not be sufficient to reduce the oncogenic potential exerted by E6. Altogether, our study unleashed the mechanism of how HPVE6 deploy AurA to promote cancer phenotypes, particularly through dysregulation of cell cycle checkpoints and suggests that the AurA-E6 complex possesses a therapeutic value. IMPORTANCE We unveiled the mechanism of how HPV employs Aurora kinase A (AurA) of host cells to exert its oncogenic capability synergistically. We systematically characterized the mode of interaction between E6-encoded by cancer-causing HPV and AurA. Then, we delineated the consequences of AurA-E6 complex formation on AurA kinase function and changes to cellular events at molecular levels. Using a cell-based approach, we unleashed that disruption of AurA-E6 association can halt cancer phenotype exhibited by HPV-positive cancer cells. Our findings are vital for the designing of state-of-the-art therapies for HPV-associated cancers.

Treating Head and Neck Cancer in the Age of Immunotherapy: A 2023 Update

Most patients diagnosed with head and neck squamous cell carcinoma (HNSCC) will present with locally advanced disease, requiring multimodality therapy. While this approach has a curative intent, a significant subset of these patients will develop locoregional failure and/or distant metastases. The prognosis of these patients is poor, and therapeutic options other than palliative chemotherapy are urgently needed. Epidermal growth factor receptor (EGFR) overexpression is an important factor in the pathogenesis of HNSCC, and a decade ago, the EGFR targeting monoclonal antibody cetuximab was approved for the treatment of late-stage HNSCC in different settings. In 2016, the anti-programmed death-1 (PD-1) immune checkpoint inhibitors nivolumab and pembrolizumab were both approved for the treatment of patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy, and in 2019, pembrolizumab was approved for first-line treatment (either as monotherapy in PD-L1 expressing tumors, or in combination with chemotherapy). Currently, trials are ongoing to include immune checkpoint inhibition in the (neo)adjuvant treatment of HNSCC as well as in novel combinations with other drugs in the recurrent/metastatic setting to improve response rates and survival and help overcome resistance mechanisms to immune checkpoint blockade. This article provides a comprehensive review of the management of head and neck cancers in the current era of immunotherapy.

A Mitochondrion-Targeting Protein (B2) Primes ROS/Nrf2-Mediated Stress Signals, Triggering Apoptosis and Necroptosis in Lung Cancer

The betanodavirus B2 protein targets mitochondria and triggers mitochondrion-mediated cell death signaling in lung cancer cells; however, its molecular mechanism remains unknown. In this study, we observed that B2 triggers hydrogen peroxide/Nrf2-involved stress signals in the dynamic regulation of non-small lung cancer cell (NSCLC)-programmed cell death. Here, the B2 protein works as a necrotic inducer that triggers lung cancer death via p53 upregulation and RIP3 expression, suggesting a new perspective on lung cancer therapy. We employed the B2 protein to target A549 lung cancer cells and solid tumors in NOD/SCID mice. Tumors were collected and processed for the hematoxylin and eosin staining of tissue and cell sections, and their sera were used for blood biochemistry analysis. We observed that B2 killed an A549 cell-induced solid tumor in NOD/SCID mice; however, the mutant ΔB2 did not. In NOD/SCID mice, B2 (but not ΔB2) induced both p53/Bax-mediated apoptosis and RIPK3-mediated necroptosis. Finally, immunochemistry analysis showed hydrogen peroxide /p38/Nrf2 stress strongly inhibited the production of tumor markers CD133, Thy1, and napsin, which correlate with migration and invasion in cancer cells. This B2-triggered, ROS/Nrf2-mediated stress signal triggered multiple signals via pathways that killed A549 lung cancer tumor cells in vivo. Our results provide novel insight into lung cancer management and drug therapy.

Piperine Reduces Neoplastic Progression in Cervical Cancer Cells by Downregulating the Cyclooxygenase 2 Pathway

Cervical cancer is the fourth-most common type of cancer in the world that causes death in women. It is mainly caused by persistent infection by human papillomavirus (HPV) that triggers a chronic inflammatory process. Therefore, the use of anti-inflammatory drugs is a potential treatment option. The effects of piperine, an amino alkaloid derived from Piper nigrum, are poorly understood in cervical cancer inflammation, making it a target of research. This work aimed to investigate the antitumor effect of piperine on cervical cancer and to determine whether this effect is modulated by the cyclooxygenase 2 (PTGS2) pathway using in vitro model of cervical cancer (HeLa, SiHa, CaSki), and non-tumoral (HaCaT) cell lines. The results showed that piperine reduces in vitro parameters associated with neoplastic evolution such as proliferation, viability and migration by cell cycle arrest in the G1/G0 and G2/M phases, with subsequent induction of apoptosis. This action was modulated by downregulation of cyclooxygenase 2 (PTGS2) pathway, which in turn regulates the secretion of cytokines and the expression of mitogen-activated protein kinases (MAPKs), metalloproteinases (MMPs), and their antagonists (TIMPs). These findings indicate the phytotherapeutic potential of piperine as complementary treatment in cervical cancer.

Human Papillomavirus 42 Drives Digital Papillary Adenocarcinoma and Elicits a Germ Cell-like Program Conserved in HPV-Positive Cancers

The skin is exposed to viral pathogens, but whether they contribute to the oncogenesis of skin cancers has not been systematically explored. Here we investigated 19 skin tumor types by analyzing off-target reads from commonly available next-generation sequencing data for viral pathogens. We identified human papillomavirus 42 (HPV42) in 96% (n = 45/47) of digital papillary adenocarcinoma (DPA), an aggressive cancer occurring on the fingers and toes. We show that HPV42, so far considered a nononcogenic, "low-risk" HPV, recapitulates the molecular hallmarks of oncogenic, "high-risk" HPVs. Using machine learning, we find that HPV-driven transformation elicits a germ cell-like transcriptional program conserved throughout all HPV-driven cancers (DPA, cervical carcinoma, and head and neck cancer). We further show that this germ cell-like transcriptional program, even when reduced to the top two genes (CDKN2A and SYCP2), serves as a fingerprint of oncogenic HPVs with implications for early detection, diagnosis, and therapy of all HPV-driven cancers.

SIGNIFICANCE

We identify HPV42 as a uniform driver of DPA and add a new member to the short list of tumorigenic viruses in humans. We discover that all oncogenic HPVs evoke a germ cell-like transcriptional program with important implications for detecting, diagnosing, and treating all HPV-driven cancers. See related commentary by Starrett et al., p. 17. This article is highlighted in the In This Issue feature, p. 1.

Methyltransferase Inhibition Enables Tgf Driven Induction of CDKN2A and B in Cancer Cells

CDKN2A/B deletion or silencing is common across human cancer, reinforcing the general importance of bypassing its tumor suppression in cancer formation or progression. In rhabdomyosarcoma (RMS) and neuroblastoma, two common childhood cancers, the three CDKN2A/B transcripts are independently expressed to varying degrees, but one, ARF, is uniformly silenced. Although TGFβ induces certain CDKN2A/B transcripts in HeLa cells, it was unable to do so in five tested RMS lines unless the cells were pretreated with a broadly acting methyltransferase inhibitor, DZNep, or one targeting EZH2. CDKN2A/B induction by TGFβ correlated with de novo appearance of three H3K27Ac peaks within a 20 kb cis element ∼150 kb proximal to CDKN2A/B. Deleting that segment prevented their induction by TGFβ but not a basal increase driven by methyltransferase inhibition alone. Expression of two CDKN2A/B transcripts was enhanced by dCas9/CRISPR activation targeting either the relevant promoter or the 20 kb cis elements, and this "precise" manipulation diminished RMS cell propagation in vitro. Our findings show crosstalk between methyltransferase inhibition and TGFβ-dependent activation of a remote enhancer to reverse CDKN2A/B silencing. Though focused on CDKN2A/B here, such crosstalk may apply to other TGFβ-responsive genes and perhaps govern this signaling protein's complex effects promoting or blocking cancer.

Activating transcription factor 3 inhibits NF‑κB p65 signaling pathway and mediates apoptosis and cell cycle arrest in cervical cancer cells

BACKGROUND

As a novel tumor suppressor mediator, activating transcription factor 3 (ATF3) has recently aroused an interest in its possible therapeutic applications in various cancers. In this study, we evaluated the effect of ATF3 overexpression on the cellular level of nuclear factor kappa B (NF-κB) in human papillomavirus (HPV)-infected Ca Ski cells. Further, we examined whether ATF3 could mediate cell cycle arrest and alter the apoptosis level of Ca Ski cells.

METHODS

The biological behavior of Ca Ski cells was evaluated prior and subsequent to the overexpression of ATF3 by MTT assay, fluorescence microscopy, cell cycle and annexin V/PI flow cytometric analysis. The effect of ectopic ATF3 expression on the cellular level of NF-κB in HPV-positive cells was evaluated by western blotting assay.

RESULTS

The overexpression of ATF3 in Ca Ski cells led to significant apoptosis and cell cycle arrest in the G1 phase. Western blotting assay revealed a discernible reduction of NF-κB p65 level in cervical cancer cells.

CONCLUSION

ATF3 acts as a tumor suppressor factor in HPV16-infected Ca Ski cells and exerts anti-cancer effects on HPV16-related cervical cancer cells potentially by hindering cell growth and inducing cell cycle arrest through the down-regulation of NF-κB. Our results suggest that ATF3 induction or NF-κB suppression may be useful targets for HPV16-related cervical cancer prevention and treatment.

Systematic Analysis of IL-1 Cytokine Signaling Suppression by HPV16 Oncoproteins

The human papillomavirus (HPV) E6 and E7 oncogenes are expressed at all stages of HPV-mediated carcinogenesis and are essential drivers of cancers caused by high-risk HPV. Some of the activities of HPV E6 and E7, such as their interactions with host cellular tumor suppressors, have been characterized extensively. There is less information about how high-risk HPV E6 and E7 alter cellular responses to cytokines that are present in HPV-infected tissues and are an important component of the tumor microenvironment. We used several models of HPV oncoprotein activity to assess how HPV16 E6 and E7 alter the cellular response to the proinflammatory cytokine IL-1β. Models of early stage HPV infection and of established HPV-positive head and neck cancers exhibited similar dysregulation of IL-1 pathway genes and suppressed transcriptional responses to IL-1β treatment. Such overlap in cell responses supports that changes induced by HPV16 E6 and E7 early in infection could persist and contribute to a dysregulated immune environment throughout carcinogenesis. HPV16 E6 and E7 also drove the upregulation of several suppressors of IL-1 cytokine signaling, including SIGIRR, both in primary keratinocytes and in cancer cells. SIGIRR knockout was insufficient to increase IL-1β-dependent gene expression in the presence of HPV16 E6 and E7, suggesting that multiple suppressors of IL-1 signaling contribute to dampened IL-1 responses in HPV16-positive cells. IMPORTANCE Human papillomavirus (HPV) infection is responsible for nearly 5% of the worldwide cancer burden. HPV-positive tumors develop over years to decades in tissues that are subject to frequent stimulation by proinflammatory cytokines. However, the effects of HPV oncoproteins on the cellular response to cytokine stimulation are not well defined. We analyzed IL-1 cytokine signaling in several models of HPV biology and disease. We found that HPV16 E6 and E7 oncoproteins mediate a broad and potent suppression of cellular responses to IL-1β in models of both early and late stages of carcinogenesis. Our data provide a resource for future investigation of IL-1 signaling in HPV-positive cells and cancers.

Adeno-associated virus infection and its impact in human health: an overview

Discovered as a contaminant of adenovirus stocks in the 1960s, adeno-associated virus (AAV) is a mono-stranded DNA virus that depends on helper factors to replicate. Even though AAV is endemic in the human population (35-80%), it is remarkable that many issues concerning the natural infection by this virus remain unanswered. In this study, we reflect on the main basic aspects of AAV biology and provide an overview of the studies exploring the impact of AAV infection on human health, focusing on three major research areas including, (i) cervical and (ii) liver cancer, and (iii) reproductive system disorders. Conflicting results have been obtained into the association of AAV infection with the occurrence of adverse reproductive outcomes, such as placental complications, spontaneous abortion, and fertility disorders, or with a protective role in HPV-related cervical carcinogenesis. Noteworthy, recent reports have identified AAV insertional mutagenesis as a novel risk factor for the development of hepatocellular carcinoma. This latest finding raises concern regarding the widespread usage of AAV vectors in liver-targeted gene therapy.

Human Papillomavirus Oncoproteins Confer Sensitivity to Cisplatin by Interfering with Epidermal Growth Factor Receptor Nuclear Trafficking Related to More Favorable Clinical Survival Outcomes in Non-Small Cell Lung Cancer

Simple Summary

Lung cancer is the leading cause of cancer death in the world. Identifying prognostic factors is crucial to improve the survival time of those with lung cancer. Our previous studies have reported that human papillomavirus (HPV) infections and epidermal growth factor receptor (EGFR) expression are associated with a better survival prognosis in lung adenocarcinoma. The purpose of this study was to detect the molecular evidence of HPV oncoproteins interfering with EGFR nuclear trafficking related to better prognosis in lung cancer. Based on the study results for a better response to cisplatin in transfected HPV 16E5/16E6/16E7 H292 xenograft animal models, as well as better survival in lung adenocarcinoma patients with either 16E6/18E6 or EGFR expression, we suggest that clinicians should adjust the treatment protocol according to HPV 16E6/18E6 expression and EGFR expression to increase the overall survival time in lung cancer.

Abstract

High-risk human papillomavirus (HPV) infections and epidermal growth factor receptor (EGFR) expression have been reported to be associated with more favorable survival outcomes in lung adenocarcinoma patients. In this study, we utilized transfected HPV 16E5/16E6/16E7 H292 cells to investigate the mechanism of HPV oncoproteins interfering with EGFR nuclear trafficking related to a better response to cisplatin. Furthermore, we correlated HPV 16E6/18E6 expression and differentially localized EGFR expression with the clinical association and survival impact in lung adenocarcinoma patients. Our results found significantly higher phosphorylated nuclear EGFR expression upon epidermal growth factor stimulus and better responses to cisplatin in transfected HPV 16E5/16E6/16E7 NCI-H292 cells and xenograft animal models. Our data were compatible with clinical results of a high correlation of HPV 16E6/18E6 and EGFR expression in non-small cell lung cancer tissues and the synergistic effects of both with the best survival prognosis in a lung adenocarcinoma cohort, especially in patients with older age, no brain metastasis, smoking history, and wild-type EGFR status. Cumulatively, our study supports HPV 16E5/16E6/16E7 oncoproteins interfering with EGFR nuclear trafficking, resulting in increased sensitivity to cisplatin. HPV 16E6/18E6 and EGFR expression serve as good prognostic factors in lung adenocarcinoma patients.

Human Papillomavirus Infection and Oropharyngeal and Gastrointestinal Cancers: A Causal Relationship?

The human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. The risk of being infected at least once in a lifetime among both men and women is estimated to be 50%. Although the majority of HPV infections are asymptomatic and improve within 2 years, approximately 10% of individuals develop a persistent infection and have an increased risk of developing carcinomas. The association of HPV and genital cancer is well established. However, there is evidence that HPV may also be associated with other cancers, including those of the gastrointestinal system. The aim of this review is to organize the current evidence of associations between HPV infections and oropharyngeal and gastrointestinal cancers, including the following: oropharyngeal, esophageal, gastric, colorectal, and anal cancers. A comprehensive review of the most up-to-date medical literature concluded that an HPV infection might have a role in the oncogenesis of gastrointestinal tract cancers. HPV may have a causal relationship with oropharyngeal and esophageal squamous cell cancers. However, the association between HPV and gastric and colorectal cancers is weaker. The development of cancer in the oropharyngeal and gastrointestinal tract is usually multifactorial, with HPV having a role in at least a subset of these cancers. HPV infections pose a big challenge due to their burden of infection and their oncogenic potential.

A common pathway to cancer: Oncogenic mutations abolish p53 oscillations

The tumor suppressor p53 oscillates in response to DNA double-strand breaks, a behavior that has been suggested to be essential to its anti-cancer function. Nearly all human cancers have genetic alterations in the p53 pathway; a number of these alterations have been shown to be oncogenic by experiment. These alterations include somatic mutations and copy number variations as well as germline polymorphisms. Intriguingly, they exhibit a mixed pattern of interactions in tumors, such as co-occurrence, mutual exclusivity, and paradoxically, mutual antagonism. Using a differential equation model of p53-Mdm2 dynamics, we employ Hopf bifurcation analysis to show that these alterations have a common mode of action, to abolish the oscillatory competence of p53, thereby, we suggest, impairing its tumor suppressive function. In this analysis, diverse genetic alterations, widely associated with human cancers clinically, have a unified mechanistic explanation of their role in oncogenesis.