HPV16 E7 Research Articles

Human papillomavirus E6/E7 oncoproteins promote radiotherapy-mediated tumor suppression by globally hijacking host DNA damage repair.

Rationale: Whatever the mucosa primary infected, HPV-positive cancers are traditionally associated with a favorable outcome, attributable to a high sensitivity to radiation therapy. However, the direct impact of viral E6/E7 oncoproteins on the intrinsic cellular radiosensitivity (and, globally, on host DNA repair) remains mostly speculative. Methods: Using several isogenic cell models expressing HPV16 E6 and/or E7, the effect of viral oncoproteins on global DNA damage response was first investigated by in vitro/in vivo approaches. The binary interactome of each individual HPV oncoprotein with factors involved in the various host DNA damage/repair mechanisms was then precisely mapped by Gaussia princeps luciferase complementation assay (and validated by co-immunoprecipitation). The stability/half-life of protein targets for HPV E6 and/or E7 as well as their subcellular localizations were determined. At last, the host genome integrity following E6/E7 expression and the synergy between radiotherapy and compounds targeting DNA repair were analyzed. Results: We first showed that the sole expression of one viral oncoprotein from HPV16 was able to significantly increase the sensitivity to irradiation of cells without affecting their basal viability parameters. In total, 10 novel targets (CHEK2, CLK2, CLK2/3, ERCC3, MNAT1, PER1, RMI1, RPA1, UVSSA and XRCC6) for E6 and 11 (ALKBH2, CHEK2, DNA2, DUT, ENDOV, ERCC3, PARP3, PMS1, PNKP, POLDIP2 and RBBP8) for E7 were identified. Importantly, not degraded following their interaction with E6 or E7, these proteins have been shown to be less linked to host DNA and to colocalize with HPV replication foci, denoting their crucial implication in viral life cycle. Finally, we found that E6/E7 oncoproteins globally jeopardize host genome integrity, increase the cellular sensitivity to DNA repair inhibitors and enhance their synergy with radiotherapy. Conclusion: Taken together, our findings provide a molecular insight into the direct hijacking of host DNA damage/repair responses by HPV oncoproteins, demonstrate the significant impact of this phenomenon on both intrinsic cellular radiosensitivity and host DNA integrity and suggest novel connected therapeutic vulnerabilities.

Abstract 1774: Understanding the interaction between the HPV E2 protein and its binding site variants

Abstract 1774: Understanding the interaction between the HPV E2 protein and its binding site variants

Single-cell transcriptomic analysis of the role of HPV16-positive macrophages in cervical cancer prognosis.

Almost all cases of cervical cancer (CC) can be attributed to high-risk HPVs infections in keratinocytes. However, it is unknown whether HPV invades immune cells such as macrophages and T cells. We analyzed the single-cell transcriptome of the CC and its adjacent tissues and found that HPV16 genes, including E1, E6, and E7, expressed in the macrophages and CD8+ T cells in addition to the malignant cells. HPV16+ macrophages highly expressed the genes that promote cell adhesion and the favorable genes such as WAS, IQCB1, MYO1F, and PDZD11 in CC prognosis. The transcription factor KLF5 potentially accounted for the induction of these protective genes and thus facilitated the infiltration of the immune cells in tumor tissues. Our single-cell transcriptome analysis suggests the potential value of the HPV16+ macrophage in CC prognosis. However, extensive experimental studies investigating the characteristics and functions of the HPV+ immune cells are still required. This article is protected by copyright. All rights reserved.

Efficacy and Synergy with Cisplatin of an Adenovirus Vectored Therapeutic E1E2E6E7 Vaccine against HPV Genome-Positive C3 Cancers in Mice.

Human papillomavirus (HPV) infections are the main cause of cervical and oropharyngeal cancers. As prophylactic vaccines have no curative effect, an efficient therapy would be highly desired. Most therapeutic vaccine candidates target only a small subset of HPV regulatory proteins, namely, E6 and E7, and are therefore restricted in the breadth of their immune response. However, research has suggested E1 and E2 as promising targets to fight HPV+ cancer. Here, we report the design of adenoviral vectors efficiently expressing HPV16 E1 and E2 in addition to transformation-deficient E6 and E7. Vaccination elicited vigorous CD4+ and CD8+ T-cell responses against all encoded HPV16 proteins in outbred mice and against E1 and E7 in C57BL/6 mice. Therapeutic vaccination of C3 tumor-bearing mice led to significantly reduced tumor growth and enhanced survival for both small and established tumors. Tumor biopsies revealed increased numbers of tumor-infiltrating CD8+ T cells in treated mice. Cisplatin enhanced the effect of therapeutic vaccination, accompanied by enhanced infiltration of dendritic cells into the tumor. CD8+ T cells were identified as effector cells in T-cell depletion assays, seemingly under regulation by FoxP3+CD4+ regulatory T cells. Finally, therapeutic vaccination with Ad-Ii-E1E2E6E7 exhibited significantly enhanced survival compared with vaccination with two peptides each harboring a known E6/E7 epitope. We hypothesize that this difference could be due to the induction of additional T-cell responses against E1. These results support the use of this novel vaccine candidate targeting an extended set of antigens (Ad-Ii-E1E2E6E7), in combination with cisplatin, as an advanced strategy to combat HPV+ cancers.

Adaptive immune response in pathogenesis and treatment of head and neck squamous cell carcinoma: the influence of immunosuppression factors and gender

An obvious trend of the last decade in head and neck squamous cell carcinoma pathogenesis evaluation is awareness of the impact of immune response disorders on disease manifestation. The review presents an analysis of the differences in the type and degree of immunosuppression, as well as treatment response in head and neck squamous cell carcinoma patients in accordance with influencing carcinogenic factor, gender, age of the patient and concomitant diseases. An increase in CD8+ T-lymphocytes and a decrease of memory T-cells has been evaluated in smoking and alcohol abusing patients with head and neck squamous cell carcinoma, and a smaller number of CD8+ T-lymphocytes were detected in the tumor microenvironment compared to non-smoking and non-drinking patients. Studies have shown that the improved prognosis of patients with human papillomavirus (Hpv) – associated head and neck squamous cell carcinoma is largely due to the presence of antibodies against Hpv E6 and E7, E7-specific CD8+T lymphocytes in periphe ral blood and a high level of tumor-infiltrating T lymphocytes. The issue of gender differences in the type of immune response is widely discussed. It has been shown that the use of immune response checkpoint inhibitors is more effective in improving survival rates in men, and the use of these drugs in combination with chemotherapy is more effective in women. In addition, in elderly cancer patients, numerous age-associated T-lymphocyte’s function changes were revealed, including a decrease in the number of naive T-lymphocytes due to age-related involution of the thymus and an in crease in the relative number of memory cells and effector cells. Thus, it is clear that immunosuppression type, as well as treatment response, differ depending on the influencing factor, gender, age of the patient, as well as comorbidities.

Resveratrol against Cervical Cancer: Evidence from In Vitro and In Vivo Studies.

Cervical cancer affects many women worldwide, with more than 500,000 cases diagnosed and approximately 300,000 deaths each year. Resveratrol is a natural substance of the class of phytoalexins with a basic structure of stilbenes and has recently drawn scientific attention due to its anticancer properties. The purpose of this review is to examine the effectiveness of resveratrol against cervical cancer. All available in vitro and in vivo studies on cervical cancer were critically reviewed. Many studies utilizing cervical cancer cells in culture reported a reduction in proliferation, cell cycle arrest, and induction of apoptosis. Apart from apoptosis, induction of autophagy was seen in some studies. Importantly, many studies have shown a reduction in the HPV oncoproteins E6 and E7 and increased levels of the tumor suppressor p53 with resveratrol treatment. A few studies examined the effects of resveratrol administration in mice ectopic-xenografted with cervical cancer cells showing reduced tumor volume and weight. Overall, the scientific data show that resveratrol has the ability to target/inhibit certain signaling molecules (EGFR, VEGFR, PKC, JNK, ERK, NF-kB, and STAT3) involved in cervical cancer cell proliferation and survival. Further in vivo experiments and clinical studies are required to better understand the potential of resveratrol against cervical cancer.

RIPOR2 Expression Decreased by HPV-16 E6 and E7 Oncoproteins: An Opportunity in the Search for Prognostic Biomarkers in Cervical Cancer.

High-risk human papillomavirus (HPV) infection is the main risk factor for cervical cancer (CC) development, where the continuous expression of E6 and E7 oncoproteins maintain the malignant phenotype. In Mexico, around 70% of CC cases are diagnosed in advanced stages, impacting the survival of patients. The aim of this work was to identify biomarkers affected by HPV-16 E6 and E7 oncoproteins that impact the prognosis of CC patients. Expression profiles dependent on E6 and E7 oncoproteins, as well as their relationship with biological processes and cellular signaling pathways, were analyzed in CC cells. A comparison among expression profiles of E6- and E7-expressing cells and that from a CC cohort obtained from The Cancer Genome Atlas (TCGA) demonstrated that the expression of 13 genes impacts the overall survival (OS). A multivariate analysis revealed that the downregulated expression of RIPOR2 was strongly associated with a worse OS. RIPOR2, including its transcriptional variants, were overwhelmingly depleted in E6- and E7-expressing cells. Finally, in a Mexican cohort, it was found that in premalignant cervical lesions, RIPOR2 expression decreases as the lesions progress; meanwhile, decreased RIPOR2 expression was also associated with a worse OS in CC patients.

183P COMMANDER-001: Initial safety data from a phase I/II dose escalation/expansion study of SQZ-eAPC-HPV, a cell-based mRNA therapeutic cancer vaccine for HPV16+ solid tumors

SQZ-eAPC-HPV (eAPC) is an autologous, cell based, HLA-genotype agnostic HPV therapeutic cancer vaccine that leverages clinical and manufacturing experience from the SQZ-PBMC-HPV clinical candidate (NCT04084951). eAPC is engineered from peripheral blood mononuclear cells by using Cell Squeeze® technology to simultaneously deliver 5 mRNAs encoding for full length HPV16 E6 and E7 proteins, CD86, and membrane-bound (mb) IL-2 and mbIL-12 cytokines. By driving co-localized MHC-I antigen presentation (E6/E7), costimulation (CD86), and cytokine signaling (IL-2/IL-12), the eAPCs may enable more potent T cell activation and proliferation while limiting known toxicity of interleukin therapy.

Exploiting the immunogenic potential of standard of care radiation or cisplatin therapy in preclinical models of HPV-associated malignancies

BackgroundWhile radiation and chemotherapy are primarily purposed for their cytotoxic effects, a growing body of preclinical and clinical evidence demonstrates an immunogenic potential for these standard therapies. Accordingly, we sought...

Transcription factor c-Rel regulated by E5 affects the whole process after HPV16 infection through miR-133a-modulated feedback loop aim at mir-379-369 cluster

BackgroundDuring the development of cervical cancer, HPV infection causes a series of changes in transcription factors and microRNAs. But their relationships with pathogenic processes are not clear.MethodsBase on previous study, to analyse the relationship among HPV16 infection and the related transcription factors, related miRNAs, so as to further understand the molecular mechanism of HPV16 infection to cervical cancer, around the HPV16 related miRNAs we have reported, the methods of bioinformatics prediction, histology, cell model in vitro and molecular interaction were used for prediction and validation respectivelyResultsThe results showed that NF-κB family members(c-Rel, p65 and p50) were identified as main HPV16rmiR-transcription factors. They have different expressive characteristics in cervical lesions and play tumorigenesis or progression roles in different periods of HPV16 infection. c-Rel, p65 and p50 act as mediators which link the HPV16 E5 and HPV16 related miRNAs. Among them, c-Rel affects the occurrence and progression of cervical cancer during whole HPV16 infection stage through miR133a-3p–modulated mir-379-369 cluster with a positive feedback way which targeted c-Rel itself and its positive regulator AKT3.ConclusionSo in the course of HPV16 infection, the E5, c-Rel, and miR-133a-3p form a positive feedback system which aim at mir-379-369 cluster for the whole process from HPV16 infection to cervical cancer.

HPV 16 E6 promotes growth and metastasis of esophageal squamous cell carcinoma cells in vitro.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. Increasing evidence suggests that human papillomavirus (HPV) infection may be associated with the etiology of ESCC. However, the precise role of HPV in ESCC remains unclear. Proliferation and apoptosis of ESCC cells upon infection with HPV16 E6 were detected using CCK-8 assays and Western blot analyses. The migration rate was measured with a wound healing assay, and a Transwell Matrigel invasion assay was used to detect the invasive ability. RT-qPCR was performed to detect the expression of E6AP, p53, and miR-34a. The proliferation rates were significantly higher in HPV16E6-transfected cell groups compared with the negative control groups. Bax protein expression was downregulated in HPV16E6-treated groups compared to the controls. The wound healing and Transwell Matrigel invasion assays indicated that HPV16 E6 infection could increase ESCC cell migration and invasion. Furthermore, E6AP, p53 and miR-34a expression were decreased in HPV16 E6-transfected cell lines. Our results not only provide evidence that HPV16 E6 promotes cell proliferation, migration, and invasion in ESCC, but also suggests a correlation between HPV infection and E6AP, p53 and miR-34a expression. Consequently, HPV16 E6 may play an important role in ESCC development.

Human Papillomavirus E1 Protein Regulates Gene Expression in Cells Involved in Immune Response.

Human papillomavirus belongs to papovaviridae family papillomavirus A, a spherical deoxyribonucleic acid (DNA) virus, which can cause the proliferation of squamous epithelial cells of human skin or mucous membranes. With the rapid increase in the incidence of condyloma acuminatum among STDs and the increase in diseases caused by HPV infection, HPV infection has seriously endangered human health. In this paper, the in vitro detection of HPV E1 protein was realized using AgNCs-dsDNA. And through the test of this detection method, we calculated that the detection limit of this method is 0.886nM. Compared with other methods for detecting E1 protein in vitro, this method has high sensitivity and simple operation. In addition, the detection method also has good anti-interference and selectivity, and can realize the detection of E1 in serum samples. The transfection efficiency of BLV-miR-B4-3p mimics at different time points was determined by quantitative real-time PCR (qPCR); the transcriptome sequencing of lymphocytes transfected with different concentrations of BLV-miR-B4-3p mimics was performed, and differential gene clustering was performed on the sequencing results. And the BLV-miR-B4-3p target gene prediction and transcriptome analysis results were verified by qPCR. The effects of BLV-miR-B4-3p on the transcriptional levels of immune-related cytokines in human lymphocytes were analyzed. Transcriptome sequencing analysis showed that after BLV-miR-B4-3p entered lymphocytes, a total of 556 differentially expressed genes were obtained. GO enrichment and KEGG analysis results showed that BLV-miR-B4-3p could independently activate influenza. The signaling pathway ultimately affects the body's immune system process, stress response, defense response, immune response, and other biological processes. After BLV-miR-B4-3p enters lymphocytes, it will lead to abnormal lymphocyte immune function, including the mRNA expression of TNF-α in Th1 cytokines which was significantly increased (P < 0.05), and the expression of IL-10 in Th2 cytokines was significantly increased (P < 0.05). The mRNA expression was significantly decreased (P < 0.05), and the mRNA expression of IL-27 was significantly increased (P < 0.001), which did not affect the mRNA expression of lymphocyte proliferation and activation-related regulators. The tumor suppressor breast cancer 1 (BRCA1) and antimicrobial peptide CAMP were significantly increased, and decreased (P < 0.001), and the expression of pro-apoptotic factor Caspase9 showed a significant downward trend (P < 0.05).

Alteration of the IFN-Pathway by Human Papillomavirus Proteins: Antiviral Immune Response Evasion Mechanism.

A persistent infection with the so-called high-risk Human Papillomaviruses (hr-HPVs) plays a fundamental role in the development of different neoplasms. The expression of the HPV proteins throughout the different steps of the viral life cycle produce a disruption of several cellular processes, including immune response, which can lead to cell transformation. The interferon-mediated response plays an important role in eliminating HPV-infected and -transformed cells. The ability of HPV to disrupt the proper function of the interferon response is based on a series of molecular mechanisms coordinated by HPV proteins intended to prevent clearance of infection, ultimately producing an immunotolerant environment that facilitates the establishment of persistence and cancer. In this review, we focus on the molecular actions performed by HPV E1, E2, E5, E6 and E7 proteins on IFN signaling elements and their contribution to the establishment of infection, viral persistence and the progression to cancer.

Human papillomavirus is an important risk factor for esophageal carcinoma in a Chinese population

PurposeDifferent types of HPV have been associated with cancer in humans, but the role of HPV in esophageal cancer (EC) is controversial. The purpose of this study was to evaluate the correlation between HPV infection and EC in the Chinese population and to provide the scientific basis for the future prevention, control, early diagnosis, and treatment strategies of EC in China.MethodsPCR detected HPV infection in 1112 esophageal cancer tissue samples, and 89 HPV-positive samples were detected by genotyping. Proximity ligation assays (PLAs) and immunohistochemistry were used to detect the expression of HPV E6 and E7 proteins. Real-time fluorescent quantitative PCR was used to detect the integration of HPV16 E6. The level of HPV-specific antibody IgG in serum was detected by ELISA and PLA.ResultsThe positive rates of HPV L1, HPV16, HPV18, hpv16 + 18 E6 and hpv16/18 E6 in 1,112 EC tissue samples were 77.6%, 41.4%, 27.2%, 14.2% and 55.4% respectively. Multiple HPV subtypes were detected in HPV-positive EC samples. PLA showed that E6 and E7 were expressed in EC109 and formed complexes with p53 and pRb, respectively. Immunohistochemistry showed that the positive rates of hpv16 + 18 E6 and E7 in HPV-positive EC samples were 56.4% and 37.0%, respectively. HPV-DNA integration rate in HPV-positive EC tissues (88.79%) was higher than that in adjacent tissues (54.17%). HPV antibody was found in the serum of EC patients by a serological test.ConclusionThe study suggests that HPV, especially HPV16 and HPV18, the infection may be a risk factor for EC in the Chinese population and that the E6 protein may play a key role in HPV-associated malignancies. These results may be important for the prevention and treatment of HPV-positive EC in China.

Biomolecular Condensation of the Human Papillomavirus E2 Master Regulator with p53: Implications in Viral Replication

p53 exerts its tumour suppressor activity by modulating hundreds of genes and it can also repress viral replication. Such is the case of human papillomavirus (HPV) through targeting the E2 master regulator, but the biochemical mechanism is not known. We show that the C-terminal DNA binding domain of HPV16 E2 protein (E2C) triggers heterotypic condensation with p53 at a precise 2/1 E2C/p53 stoichiometry at the onset for demixing, yielding large regular spherical droplets that increase in size with E2C concentration. Interestingly, transfection experiments show that E2 co-localizes with p53 in the nucleus with a grainy pattern, and recruits p53 to chromatin-associated foci, a function independent of the DNA binding capacity of p53 as judged by a DNA binding impaired mutant. Depending on the length, DNA can either completely dissolve or reshape heterotypic droplets into irregular condensates containing p53, E2C, and DNA, and reminiscent of that observed linked to chromatin. We propose that p53 is a scaffold for condensation in line with its structural and functional features, in particular as a promiscuous hub that binds multiple cellular proteins. E2 appears as both client and modulator, likely based on its homodimeric DNA binding nature. Our results, in line with the known role of condensation in eukaryotic gene enhancement and silencing, point at biomolecular condensation of E2 with p53 as a means to modulate HPV gene function, strictly dependent on host cell replication and transcription machinery.

The expression of Oct3/4A mRNA and not its isoforms is upregulated by the HPV16 E7 oncoprotein.

Oct3/4 a transcription factor is involved in maintaining the characteristics of cancer stem cells. Oct3/4 can be expressed differentially with respect to the progression of cervical cancer (CC). In addition, Oct3/4 can give rise to three isoforms by alternative splicing of the mRNA Oct3/4A, Oct3/4B and Oct3/4B1. The aim of this study was to evaluate the mRNA expression from Oct3/4A, Oct3/4B and Oct3/4B1 in low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), CC samples, and measure the effect of the HPV16 E7 oncoprotein on the mRNA expression from Oct3/4 isoforms in the C-33A cell line. The expression levels of Oct3/4A, Oct3/4B and Oct3/4B1 mRNA were analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in patients with LSILs, HSILs and CC. Additionally, C-33A cells that expressed the HPV16 E7 oncoprotein were established to evaluate the effect of E7 on the expression of Oct3/4 mRNA isoforms. Oct3/4A (p = 0.02), Oct3/4B (p = 0. 001) and Oct3/4B1 (p < 0. 0001) expression is significantly higher in patients with LSIL, HSIL and CC than in woman with non-IL. In the C-33A cell line, the expression of Oct3/4A mRNA in the presence of the E7 oncoprotein increased compared to that in nontransfected C-33A cells. Oct3/4B and Oct3/4B1 mRNA were expressed at similar levels among the different groups. These data indicate that only the mRNA of Oct3/4A is upregulated by the HPV16 E7 oncoprotein.

ZER1 Contributes to the Carcinogenic Activity of High-Risk HPV E7 Proteins.

Human papillomavirus (HPV) E7 proteins bind to host cell proteins to facilitate virus replication. Interactions between HPV E7 and host cell proteins can also drive cancer progression. We hypothesize that HPV E7-host protein interactions specific for high-risk E7 contribute to the carcinogenic activity of high-risk HPV. The cellular protein ZER1 interacts with the E7 protein from HPV16, the genotype most frequently associated with human cancers. The HPV16 E7-ZER1 interaction is unique among HPV E7 tested to date. Other E7 proteins, even from closely related HPV genotypes, do not bind ZER1, which is a substrate specificity factor for a CUL2-RING ubiquitin ligase. In the present study, we investigated the contribution of ZER1 to the carcinogenic activity of HPV16 E7. First, we mapped the ZER1 binding site to specific residues on the C terminus of HPV16 E7. We showed that the mutant HPV16 E7 that cannot bind ZER1 is impaired in the ability to promote the growth of primary keratinocytes. We found that ZER1 and CUL2 contribute to, but are not required for, HPV16 E7 to degrade RB1. Cancer dependency data show that ZER1 is an essential gene in most HPV-positive, but not HPV-negative, cancer cell lines. Depleting ZER1 impaired the growth of primary keratinocytes expressing HPV16 E7 or HPV18 E7 and of HPV16-and HPV18-positive cervical cancer cell lines. Taken together, our work demonstrates that ZER1 contributes to HPV-mediated carcinogenesis and is essential for the growth of HPV-positive cells. IMPORTANCE HPV16 is highly carcinogenic and is the most predominant HPV genotype associated with human cancers. The mechanisms that underlie differences between high-risk HPV genotypes are currently unknown, but many of these differences are likely attributable to the activities of the oncogenic HPV proteins, including E7. The HPV E7 oncoprotein is essential for HPV-mediated carcinogenesis. A large number of HPV E7 targets have been identified. However, it is unclear which of these many interactions contributes to the carcinogenic activity of HPV E7. Here, we characterized the interaction between HPV16 E7 and the host cell protein ZER1, testing whether this genotype-specific interaction could enable some of the carcinogenic activity of HPV16 E7. We found that ZER1 binding contributes to the growth-promoting activity of HPV16 E7 and to the growth of HPV-positive cervical cancer cells. We propose that ZER1 makes an important contribution to HPV-mediated carcinogenesis.

High-risk HPV infection-associated hypermethylated genes in oropharyngeal squamous cell carcinomas

BackgroundHPV-positive oropharyngeal squamous cell carcinomas (OPSCCs) are sensitive to chemo-radiation therapy and have favorable survival outcomes compared with HPV-negative cancers. These tumors are usually not related to tobacco and alcohol exposure. Therefore, diagnosing HPV-positive OPSCCs for the appropriate disease management is crucial, and no suitable markers are available for detecting early malignancies in HPV-infected tissues. In this study, we attempt to find HPV-specific epigenetic biomarkers for OPSCCs.MethodsA total of 127 surgical samples were analyzed for HPV positivity and promoter methylation of a panel of genes. HPV detection was performed by PCR detection of HPV E6 and E7 viral oncoproteins. In addition, promoter methylation of a total of 8 genes (DAPK, FHIT, RASSF1A, TIMP3, AGTR1, CSGALNACT2, GULP1 and VGF) was analyzed by quantitative-methylation specific PCR (QMSP), and their associations with HPV positivity or RB/p16 expressions were evaluated.ResultsAGTR1 and FHIT were frequently methylated in HPV-positive OPSCC samples with a good area under the curve (AUC over 0.70). In addition, these genes' promoter methylation was significantly associated with p16 positive and RB negative cases, which were the characteristics of OPSCC cases with favorable survival outcomes. Either AGTR1 or FHIT methylated cases were significantly associated with HPV-positive cancers with 92.0% sensitivity (P < 0.001). Also, they had significantly better overall survival (P = 0.047) than both unmethylated cases.ConclusionsA combination of AGTR1 and FHIT methylation demonstrated a suitable detection marker of OPSCCs derived from the HPV-infected field, familiar with p16-positive and RB-negative phenotypes.

EGFR-induced suppression of HPV E6/E7 is mediated by microRNA-9-5p silencing of BRD4 protein in HPV-positive head and neck squamous cell carcinoma

EGFR upregulation is an established biomarker of treatment resistance and aggressiveness in head and neck cancers (HNSCC). EGFR-targeted therapies have shown benefits for HPV-negative HNSCC; surprisingly, inhibiting EGFR in HPV-associated HNSCC led to inferior therapeutic outcomes suggesting opposing roles for EGFR in the two HNSCC subtypes. The current study aimed to understand the link between EGFR and HPV-infected HNSCC particularly the regulation of HPV oncoproteins E6 and E7. We demonstrate that EGFR overexpression suppresses cellular proliferation and increases radiosensitivity of HPV-positive HNSCC cell lines. EGFR overexpression inhibited protein expression of BRD4, a known cellular transcriptional regulator of HPV E6/E7 expression and DNA damage repair facilitator. Inhibition of EGFR by cetuximab restored the expression of BRD4 leading to increased HPV E6 and E7 transcription. Concordantly, pharmacological inhibition of BRD4 led to suppression of HPV E6 and E7 transcription, delayed cellular proliferation and sensitised HPV-positive HNSCC cells to ionising radiation. This effect was shown to be mediated through EGFR-induced upregulation of microRNA-9-5p and consequent silencing of its target BRD4 at protein translational level, repressing HPV E6 and E7 transcription and restoring p53 tumour suppressor functions. These results suggest a novel mechanism for EGFR inhibition of HPV E6/E7 oncoprotein expression through an epigenetic pathway, independent of MAPK, but mediated through microRNA-9-5p/BRD4 regulation. Therefore, targeting EGFR may not be the best course of therapy for certain cancer types including HPV-positive HNSCC, while targeting specific signalling pathways such as BRD4 could provide a better and potentially new treatment to improve HNSCC therapeutic outcome.

MiR-23b-3p, miR-124-3p and miR-218-5p Synergistic or Additive Effects on Cellular Processes That Modulate Cervical Cancer Progression? A Molecular Balance That Needs Attention.

In cervical cancer (CC), miR-23b-3p, miR-124-3p, and miR-218-5p have been found to act as tumor suppressors by regulating cellular processes related to progression and metastasis. The objective of the present review is to provide an update on the experimental evidence about the role of miR-23b-3p, miR-124-3p, and miR-218-5p in the regulation of CC progression. Additionally, we present the results of a bioinformatic analysis that suggest that these miRNAs have a somewhat redundant role in the same cellular processes that may result in a synergistic effect to promote CC progression. The results indicate that specific and common target genes for miR-23b-3p, miR-124-3p, and miR-218-5p regulate proliferation, migration, apoptosis, and angiogenesis, all processes that are related to CC maintenance and progression. Furthermore, several target genes may regulate cancer-related signaling pathways. We found that a total of 271 proteins encoded by the target mRNAs of miR-23b-3p, miR-124-3p, or miR-218-5p interact to regulate the cellular processes previously mentioned, and some of these proteins are regulated by HPV-16 E7. Taken together, information analysis indicates that miR-23b-3p, miR-124-3p, and miR-218-5p may potentiate their effects to modulate the cellular processes related to the progression and maintenance of CC with and without HPV-16 involvement.