Promising predictive molecular biomarkers for cervical cancer (Review)

Cervical cancer (CC) constitutes a serious public health problem. Vaccination and screening programs have notably reduced the incidence of CC worldwide by >80%; however, the mortality rate in low‑income countries remains high. The staging of CC is a determining factor in therapeutic strategies: The clinical management of early stages of CC includes surgery and/or radiotherapy, whereas radiotherapy and/or concurrent chemotherapy are the recommended therapeutic strategies for locally advanced CC. The histopathological characteristics of tumors can effectively serve as prognostic markers of radiotherapy response; however, the efficacy rate of radiotherapy may significantly differ among cancer patients. Failure of radiotherapy is commonly associated with a higher risk of recurrence, persistence and metastasis; therefore, radioresistance remains the most important and unresolved clinical problem. This condition highlights the importance of precision medicine in searching for possible predictive biomarkers to timely identify patients at risk of treatment response failure and provide tailored therapeutic strategies according to genetic and epigenetic characteristics. The present review aimed to summarize the evidence that supports the role of several proteins, methylation markers and non‑coding RNAs as potential predictive biomarkers for CC.

Molecular aspects of cervical cancer: a pathogenesis update

Cervical cancer (CC) is a significant health problem, especially in low-income countries. Functional studies on the human papillomavirus have generated essential advances in the knowledge of CC. However, many unanswered questions remain. This mini-review discusses the latest results on CC pathogenesis, HPV oncogenesis, and molecular changes identified through next-generation technologies. Interestingly, the percentage of samples with HPV genome integrations correlates with the degree of the cervical lesions, suggesting a role in the development of CC. Also, new functions have been described for the viral oncoproteins E5, E6, and E7, resulting in the acquisition and maintenance of cancer hallmarks, including proliferation, immune response evasion, apoptosis, and genomic instability. Remarkably, E5 oncoprotein affects signaling pathways involved in the expression of interferon-induced genes and EGFR-induced proliferation, while E6 and E7 oncoproteins regulate the DNA damage repair and cell cycle continuity pathways. Furthermore, next-generation technologies provide vast amounts of information, increasing our knowledge of changes in the genome, transcriptome, proteome, metabolome, and epigenome in CC. These studies have identified novel molecular traits associated with disease susceptibility, degree of progression, treatment response, and survival as potential biomarkers and therapeutic targets.

The NDV-MLS as an Immunotherapeutic Strategy for Breast Cancer: Proof of Concept in Female Companion Dogs with Spontaneous Mammary Cancer

The absence of tumor-infiltrating lymphocytes negatively impacts the response to chemotherapy and prognosis in all subtypes of breast cancer. Therapies that stimulate a proinflammatory environment may help improve the response to standard treatments and also to immunotherapies such as checkpoint inhibitors. Newcastle disease virus (NDV) shows oncolytic activity, as well as immune modulating potential, in the treatment of breast cancer in vitro and in vivo; however, its potential to enhance tumor-infiltrating immune cells in breast cancer has yet to be evaluated. Since spontaneous canine mammary tumors represent a translational model of human breast cancer, we conducted this proof-of-concept study, which could provide a rationale for further investigating NDV-MLS as immunotherapy for mammary cancer. Six female companion dogs with spontaneous mammary cancer received a single intravenous and intratumoral injection of oncolytic NDV-MLS. Immune cell infiltrates were evaluated by histology and immunohistochemistry in the stromal, intratumoral, and peritumoral compartments on day 6 after viral administration. Increasing numbers of immune cells were documented post-viral treatment, mainly in the peritumoral compartment, where plasma cells and CD3+ and CD3-/CD79- lymphocytes predominated. Viral administration was well tolerated, with no significant adverse events. These findings support additional research on the use of NDV-MLS immunotherapy for mammary cancer.

The inhibitory effect of trastuzumab on BT474 triple‑positive breast cancer cell viability is reversed by the combination of progesterone and estradiol

Breast cancer expressing the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) is known as triple-positive (TPBC). TPBC represents 9-11% of breast cancer cases worldwide and is a heterogeneous subtype. Notably, TPBC presents a therapeutic challenge due to the crosstalk between the hormonal (ER and PR) and HER2 pathways. Patients with TPBC are treated with trastuzumab (TTZ); however, several patients treated with TTZ tend to relapse. The present study aimed to investigate the effect of the PR on inhibitory effect of TTZ on cell viability. BT474 cells (a model of TPBC) and BT474 PR-silenced cells were treated with either TTZ, progesterone (Pg), the PR antagonist mifepristone (RU486) or estradiol (E2) alone or in combination for 144 h (6 days). Cell viability assays and western blotting were subsequently performed. The results showed that Pg and E2 interfered with the inhibitory effect of TTZ on cell viability and this effect was potentiated when both hormones were combined. Pg was revealed to act through the PR, mainly activating the PR isoform B (PR-B) and inducing the protein expression levels of CDK4 and cyclin D1; however, it did not reactivate the HER2/Akt pathway. By contrast, E2 was able to increase PR isoform A (PR-A) expression, which was inhibited by Pg. Notably, in most of the experiments, RU486 did not antagonize the effects of Pg. In conclusion, Pg and E2 may interfere with the inhibitory effect of TTZ on cell viability through PR-B activation and PR-A inactivation.

Accuracy and Precision of Iodine Quantification in Subtracted Micro-Computed Tomography: Effect of Reconstruction and Noise Removal Algorithms

PURPOSE

To evaluate the effect of reconstruction and noise removal algorithms on the accuracy and precision of iodine concentration (CI) quantified with subtracted micro-computed tomography (micro-CT).

PROCEDURES

Two reconstruction algorithms were evaluated: a filtered backprojection (FBP) algorithm and a simultaneous iterative reconstruction technique (SIRT) algorithm. A 3D bilateral filter (BF) was used for noise removal. A phantom study evaluated and compared the image quality, and the accuracy and precision of CI in four scenarios: filtered FBP, filtered SIRT, non-filtered FBP, and non-filtered SIRT. In vivo experiments were performed in an animal model of chemically-induced mammary cancer.

RESULTS

Linear relationships between the measured and nominal CI values were found for all the scenarios in the phantom study (R2 > 0.95). SIRT significantly improved the accuracy and precision of CI compared to FBP, as given by their lower bias (adj. p-value = 0.0308) and repeatability coefficient (adj. p-value < 0.0001). Noise removal enabled a significant decrease in bias in filtered SIRT images only; non-significant differences were found for the repeatability coefficient. The phantom and in vivo studies showed that CI is a reproducible imaging parameter for all the scenarios (Pearson r > 0.99, p-value < 0.001). The contrast-to-noise ratio showed non-significant differences among the evaluated scenarios in the phantom study, while a significant improvement was found in the in vivo study when SIRT and BF algorithms were used.

CONCLUSIONS

SIRT and BF algorithms improved the accuracy and precision of CI compared to FBP and non-filtered images, which encourages their use in subtracted micro-CT imaging.

Harnessing the post-vaccination era: Do emerging HPV types represent a new threat?

While the HPV vaccine is highly effective, it is unknown whether other, untargeted viral types could occupy empty niches to become an emerging threat. In this issue of Cell Host & Microbe, Pimenoff and colleagues present a community-level epidemiological analysis of HPV types up to 8 years after different vaccination policies.

Oral lichen planus clinician reported outcome measure: Development, content validity, and further development

OBJECTIVE

To establish and test a clinician-reported outcome measure of oral lichen planus (OLP): OLP Investigator global assessment (IGA).

METHODS

OLP IGA scale was tested with retrospective data from clinical practice and a phase II clinical trial. A comparison of the OLP IGA score with patient-reported outcomes was completed.

RESULTS

Clinical Practice: The mean (SD) OLP IGA score (0-4) in 107 OLP patients was 1.8 (1.0) with correlation of 0.25-0.48 (p value 0.01 - <0.0001) with symptom scores. There was a significant increase in OLP symptoms based on OLP IGA score.

CLINICAL TRIAL

The mean (SD) OLP IGA score in 137 research participants was 2.5 (1.2) with correlation of 0.43-0.52 (all p values <0.0001) with symptoms scores. There was a significant increase in OLP symptoms based on OLP IGA score. Forty-seven (35%) participants in the phase 2 study had an improvement in the OLP IGA score of ≥2. There were significant improvements in all symptoms scores in relation to the change in IGA score.

CONCLUSIONS

The OLP IGA is designed to assess changes in symptomatic OLP lesions and is appropriate for use across the full range of symptomatic OLP severity and represents a scale with utility in clinical practice and clinical trials.

Lysophosphatidylinositol Promotes Chemotaxis and Cytokine Synthesis in Mast Cells with Differential Participation of GPR55 and CB2 Receptors

Mast cells (MCs) are the main participants in the control of immune reactions associated with inflammation, allergies, defense against pathogens, and tumor growth. Bioactive lipids are lipophilic compounds able to modulate MC activation. Here, we explored some of the effects of the bioactive lipid lysophosphatidylinositol (LPI) on MCs. Utilizing murine bone marrow-derived mast cells (BMMCs), we found that LPI did not cause degranulation, but slightly increased FcεRI-dependent β-hexosaminidase release. However, LPI induced strong chemotaxis together with changes in LIM kinase (LIMK) and cofilin phosphorylation. LPI also promoted modifications to actin cytoskeleton dynamics that were detected by an increase in cell size and interruptions in the continuity of the cortical actin ring. The chemotaxis and cortical actin ring changes were dependent on GPR55 receptor activation, since the specific agonist O1602 mimicked the effects of LPI and the selective antagonist ML193 prevented them. The LPI and O1602-dependent stimulation of BMMC also led to VEGF, TNF, IL-1α, and IL-1β mRNA accumulation, but, in contrast with chemotaxis-related processes, the effects on cytokine transcription were dependent on GPR55 and cannabinoid (CB) 2 receptors, since they were sensitive to ML193 and to the specific CB2 receptor antagonist AM630. Remarkably, GPR55-dependent BMMC chemotaxis was observed towards conditioned media from distinct mouse and human cancer cells. Our data suggest that LPI induces the chemotaxis of MCs and leads to cytokine production in MC in vitro with the differential participation of GPR55 and CB2 receptors. These effects could play a significant role in the recruitment of MCs to tumors and the production of MC-derived pro-angiogenic factors in the tumor microenvironment.

Modulating epigenetic modifications for cancer therapy (Review)

Cancer is a global public health concern. Alterations in epigenetic processes are among the earliest genomic aberrations occurring during cancer development and are closely related to progression. Unlike genetic mutations, aberrations in epigenetic processes are reversible, which opens the possibility for novel pharmacological treatments. Non‑coding RNAs (ncRNAs) represent an essential epigenetic mechanism, and emerging evidence links ncRNAs to carcinogenesis. Epigenetic drugs (epidrugs) are a group of promising target therapies for cancer treatment acting as coadjuvants to reverse drug resistance in cancer. The present review describes central epigenetic aberrations during malignant transformation and explains how epidrugs target DNA methylation, histone modifications and ncRNAs. Furthermore, clinical trials focused on evaluating the effect of these epidrugs alone or in combination with other anticancer therapies and other ncRNA‑based therapies are discussed. The use of epidrugs promises to be an effective tool for reversing drug resistance in some patients with cancer.

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.

Synthesis and optimization of photothermal properties of NIR emitting LiGa5O8: Cr3+ and gold nanorods as hybrid materials for theranostic applications

The increase in incidence of degenerative diseases has fueled the development of novel materials, mostly focused on reducing adverse effects caused by current medical therapies. Theranostic materials represent an alternative to treat degenerative diseases, since they combine diagnostic properties and localized therapy within the same material. This work presents the synthesis and characterization of hybrid materials designed for theranostic purposes. The hybrid materials were composed of LiGa₅O₈:Cr³⁺ (LGO) with emission lines in the near infrared (NIR), hence providing an excellent diagnostic ability. As for the therapy part, the hybrid nanomaterials contained gold nanorods (AuR) with localized surface plasmon resonance (LSPR). Once AuR are excited, plasmonic processes are triggered at their surface resulting in increased localized temperature capable of inducing irreversible damage to the cells. A detailed characterization of the hybrid materials confirmed proper assembly of LGO and AuR. Moreover, these nanocomposites preserved their luminescent properties and LSPR. Finally, the cytotoxic potential of the hybrid material was evaluated in different cell lines by cell viability colorimetric assays to determine its possible use as theranostic agent. The success in the synthesis of hybrid materials based on LGO with emission in the NIR coupled with AuR, provides a new perspective for the design of hybrid materials with improved properties to be used in biomedical fields.

Reversible and bidirectional signaling of notch ligands

The Notch signaling pathway is a direct cell-cell communication system involved in a wide variety of biological processes, and its disruption is observed in several pathologies. The pathway is comprised of a ligand-expressing (sender) cell and a receptor-expressing (receiver) cell. The canonical ligands are members of the Delta/Serrate/Lag-1 (DSL) family of proteins. Their binding to a Notch receptor in a neighboring cell induces a conformational change in the receptor, which will undergo regulated intramembrane proteolysis (RIP), liberating the Notch intracellular domain (NICD). The NICD is translocated to the nucleus and promotes gene transcription. It has been demonstrated that the ligands can also undergo RIP and nuclear translocation, suggesting a function for the ligands in the sender cell and possible bidirectionality of the Notch pathway. Although the complete mechanism of ligand processing is not entirely understood, and its dependence on Notch receptors has not been ruled out. Also, ligands have autonomous functions beyond Notch activation. Here we review the concepts of reverse and bidirectional signalization of DSL proteins and discuss the characteristics that make them more than just ligands of the Notch pathway.

HPV oral and oropharynx infection dynamics in young population

The incidence of human papillomavirus (HPV)-associated cancers, especially those from the head and neck region, has increased. The relatively early age of presentation of HPV-positive head and neck cancer (HNC) indicates that viral infection might be acquired early in life. Persistent HPV infection has been recognized as the main risk factor for cancer development, but most studies have focused on evaluating HPV persistence in the genital region. Thus, in this work, we aimed to evaluate the prevalence of HPV in oral cavity and oropharynx in a young population, as well as the possible persistence of the infection after 12 months. Our results indicate that almost half (46.8%) of the analyzed population harbors an HPV infection either in the oral cavity or in the oropharynx. Furthermore, after 1 year of initial identification, half of them eliminated the infection, and only one person (5.26%) exhibited persistence. Interestingly, 50% of the individuals who successfully eliminated the infection acquired a new viral type, indicating that even when the primary infection is effectively eliminated by the immune system, there is a dynamic circulation of HR-HPV types that produce reinfection. This dynamic HPV infection among young individuals could influence the future establishment of cancer in some proportion of the cases.

The high-risk HPV E6 proteins modify the activity of the eIF4E protein via the MEK/ERK and AKT/PKB pathways

Previous studies have proposed that the human papillomavirus (HPV) E6 oncoproteins modify the transcriptional activity of eIF4E through mechanisms dependent on p53 degradation. However, the effect of these oncoproteins on pathways regulating the activity of the eIF4E protein remains poorly understood. Hence, we investigated the mechanisms whereby E6 proteins regulate the activity of the eIF4E protein and its effect on target genes. Overexpression of E6 constructs (HPV-6, HPV-16, HPV-18, and HPV52) showed that E6 oncoproteins increased phosphorylation of the eIF4E protein (Serine-209). This result was mainly mediated by phosphorylation of the 4EBP1 protein via the PI3K/AKT pathway. Additionally, the pharmacological inhibition of eIF4E phosphorylation in cervical cancer cell lines substantially reduced the protein levels of CCND1 and ODC1, indicating that E6 of the high-risk genotypes may modify protein synthesis of the eIF4E target genes by increasing the activity of the AKT and ERK pathways.

Quantitative Imaging Parameters of Contrast-Enhanced Micro-Computed Tomography Correlate with Angiogenesis and Necrosis in a Subcutaneous C6 Glioma Model

The aim of this work was to systematically obtain quantitative imaging parameters with static and dynamic contrast-enhanced (CE) X-ray imaging techniques and to evaluate their correlation with histological biomarkers of angiogenesis in a subcutaneous C6 glioma model. Enhancement (E), iodine concentration (CI), and relative blood volume (rBV) were quantified from single- and dual-energy (SE and DE, respectively) micro-computed tomography (micro-CT) images, while rBV and volume transfer constant (Ktrans) were quantified from dynamic contrast-enhanced (DCE) planar images. CI and rBV allowed a better discernment of tumor regions from muscle than E in SE and DE images, while no significant differences were found for rBV and Ktrans in DCE images. An agreement was found in rBV for muscle quantified with the different imaging protocols, and in CI and E quantified with SE and DE protocols. Significant strong correlations (Pearson r > 0.7, p < 0.05) were found between a set of imaging parameters in SE images and histological biomarkers: E and CI in tumor periphery were associated with microvessel density (MVD) and necrosis, E and CI in the complete tumor with MVD, and rBV in the tumor periphery with MVD. In conclusion, quantitative imaging parameters obtained in SE micro-CT images could be used to characterize angiogenesis and necrosis in the subcutaneous C6 glioma model.

New insights in Hippo signalling alteration in human papillomavirus-related cancers

The persistent infection with high-risk human papillomavirus (HPV) is an etiologic factor for the development of different types of cancers, mainly attributed to the continuous expression of E6 and E7 HPV oncoproteins, which regulate several cell signalling pathways including the Hippo pathway. It has been demonstrated that E6 proteins promote the increase of the Hippo elements YAP, TAZ and TEAD, at protein level, as well as their transcriptional targets. Also, E6 and E7 oncoproteins promote nuclear YAP localization and a decrease in YAP negative regulators such as MST1, PTPN14 or SOCS6. Interestingly, Hippo signalling components modulate HPV activity, such as TEAD1 and the transcriptional co-factor VGLL1, induce the activation of HPV early and late promoters, while hyperactivation of YAP in specific cells facilitates virus infection by increasing putative HPV receptors and by evading innate immunity. Additionally, alterations in Hippo signalling elements have been found in HPV-related cancers and particularly, the involvement of HPV oncoproteins on the regulation of some of these Hippo components has been also proposed, although the precise mechanisms remain unclear. The present review addresses the recent findings describing the interplay between HPV and Hippo signalling in HPV-related cancers, a fact that highlights the importance of developing more in-depth studies in this field to establish key therapeutic targets.

MOLECULAR MARKERS FOR THE DIAGNOSIS OF HIGH-RISK HUMAN PAPILLOMAVIRUS INFECTION AND TRIAGE OF HUMAN PAPILLOMAVIRUS-POSITIVE WOMEN

Infection with high-risk human papillomavirus (HPV) increases the likelihood of developing cervical cancer (CC). A plethora of cellular processes is required to produce pre-malignant lesions, which in turn may become malignant if left untreated. Those changes are induced by viral oncoproteins, which represent an ideal target to identify the viral presence, or by some particularities of the host that ultimately promote the establishment of CC. This article describes the different methods used for HPV detection and quantification, as well as the current trend of secondary screening approaches to detect premalignant lesions and CC. In addition, we analyzed validated biomarkers and those under clinical investigation for the classification (triage) of women at risk of developing CC after an initial positive HPV test and that could be used as prognostic biomarkers for CC. The use of molecular biomarkers, together with the detection of HPV DNA sequences, provides a high impact diagnostic and prognostic tool in the detection of patients at increased risk of developing CC and also may guide their clinical management. In addition, some of those biomarkers could represent pharmacological targets for the future design of therapeutic approaches to CC treatment.

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Infection with high-risk human papillomavirus (HPV) increases the likelihood of developing cervical cancer (CC). A plethora of cellular processes is required to produce pre-malignant lesions, which in turn may become malignant if left untreated. Those changes are induced by viral oncoproteins, which represent an ideal target to identify the viral presence, or by some particularities of the host that ultimately promote the establishment of CC. This article describes the different methods used for HPV detection and quantification, as well as the current trend of secondary screening approaches to detect premalignant lesions and CC. In addition, we analyzed validated biomarkers and those under clinical investigation for the classification (triage) of women at risk of developing CC after an initial positive HPV test and that could be used as prognostic biomarkers for CC. The use of molecular biomarkers, together with the detection of HPV DNA sequences, provides a high impact diagnostic and prognostic tool in the detection of patients at increased risk of developing CC and also may guide their clinical management. In addition, some of those biomarkers could represent pharmacological targets for the future design of therapeutic approaches to CC treatment.

Presence of Papillomavirus DNA sequences in the canine transmissible venereal tumor (CTVT)

Background

The canine transmissible venereal tumor (CTVT) or Sticker’s sarcoma is a neoplastic disease affecting dogs. This disease is presented as a tumoral mass in the genital organs of both, male and female individuals. Up to date, there is no clear evidence indicating a viral agent as the causative mediator for CTVT development.

Purpose

The present work aims to analyze 21 samples from canines with CTVT for molecular identification of Papillomavirus DNA sequences. In addition, microbiological analysis, cytologic and histopathologic evaluations were also performed.

Results

All patients showed no biochemical and microbiological alterations. Molecular analysis demonstrated the viral DNA presence in the samples using different primer sets. The MY primers amplified a 450 bp band in seven out of 21 samples (33%). The PVF and Fap64 primer set, targeting the L1 sequence of Canine Papillomavirus (CPV), showed positivity in 16 out of 21 samples (76%).

Conclusion

These results support the possible causative association between CPV and CTVT; nevertheless, additional studies are required to uphold such statement. This work presents evidence indicating that a viral agent might be involved in the pathogenesis of CTVT and set the bases for a better understanding of the CTVT pathobiology.

Mechanisms of Vasculogenic Mimicry in Ovarian Cancer

Solid tumors carry out the formation of new vessels providing blood supply for growth, tumor maintenance, and metastasis. Several processes take place during tumor vascularization. In angiogenesis, new vessels are derived from endothelial cells of pre-existing vessels; while in vasculogenesis, new vessels are formed de novo from endothelial progenitor cells, creating an abnormal, immature, and disorganized vascular network. Moreover, highly aggressive tumor cells form structures similar to vessels, providing a pathway for perfusion; this process is named vasculogenic mimicry (VM), where vessel-like channels mimic the function of vessels and transport plasma and blood cells. VM is developed by numerous types of aggressive tumors, including ovarian carcinoma which is the second most common cause of death among gynecological cancers. VM has been associated with poor patient outcome and survival in ovarian cancer, although the involved mechanisms are still under investigation. Several signaling molecules have an important role in VM in ovarian cancer, by regulating the expression of genes related to vascular, embryogenic, and hypoxic signaling pathways. In this review, we provide an overview of the current knowledge of the signaling molecules involved in the promotion and regulation of VM in ovarian cancer. The clinical implications and the potential benefit of identification and targeting of VM related molecules for ovarian cancer treatment are also discussed.

The Human Papillomavirus (HPV) E1 protein regulates the expression of cellular genes involved in immune response

The Human Papillomavirus (HPV) E1 protein is the only viral protein with enzymatic activity. The main known function of this protein is the regulation of the viral DNA replication. Nevertheless, it has been demonstrated that the ablation of HPV18 E1 mRNA in HeLa cells promotes a deregulation of several genes, particularly those involved in host defense mechanisms against viral infections; however, the specific contribution of E1 protein in HPV-independent context has not been studied. The aim of this work was to determine the effect of the HPV E1 protein in the regulation of cellular gene expression profiles evaluated through RNA-seq. We found that E1 proteins from HPV16 and 18 induced an overexpression of different set of genes associated with proliferation and differentiation processes, as well as downregulation of immune response genes, including IFNβ1 and IFNλ1 and Interferon-stimulated gene (ISG), which are important components involved in the antiviral immune response. Together, our results indicate that HR-(High-Risk) and LR-(Low-Risk) HPV E1 proteins play an important role in inhibiting the anti-viral immune response.

18F-FDG-PET/CT in Canine Mammary Gland Tumors

Medical imaging techniques play a central role in clinical oncology, helping to obtain important information about the extent of disease, and plan treatment. Advanced imaging modalities such as Positron Emission Tomography-Computed Tomography (PET/CT), may help in the whole-body staging in a single procedure, although the lesions should be carefully interpreted. PET/CT is becoming commonly used in canine cancer patients, but there is still limited information available on specific tumors such as mammary cancer. We evaluated the utility of fluorine-18 fluorodeoxyglucose (¹⁸F-FDG)-PET/CT to detect malignant lesions in eight female dogs with naturally occurring mammary tumors. A whole-body scan was performed prior to surgery, and mammary and non-mammary lesions detected either on PET/CT or during pre-surgical physical exam were resected when possible and submitted for histopathological examination. Multiple mammary lesions involving different mammary glands were detected in 5/8 dogs, for a total of 23 lesions; there were 11 non-mammary-located lesions in 6/8 dogs, three of these were lung or lymph node metastasis. A total of 34 lesions were analyzed: 22 malignant (19 mammary tumors and three metastatic lesions), and 12 benign (four mammary lesions and eight of non-mammary tissues). Glucose uptake by maximum standardized uptake value (SUVmax) was analyzed and correlated with tumor size, and benign vs. malignant pathology. We found that the minimum tumor size needed to distinguish malignant lesions according to the SUVmax was 1.5 cm; benign and malignant lesions <1.5 cm did not differ in glucose uptake (mean SUVmax = 1.1). In addition, a SUVmax value >2 was 100% sensitive for malignancy. Combining these data, lesions >1.5 cm with a SUVmax >2 had a positive predictive value of 100%. Finally, we did not find an association between SUVmax and histologic subtype or grade, which may be present in a larger sample. Thus, ¹⁸F-FDG PET/CT is useful for distinguishing malignant from benign lesion but further imaging of dogs with diverse tumors, should establish characteristic SUV value cutoffs for detecting primary and metastatic disease, and distinguishing them from benign lesions.

Molecular epidemiology of bacterial vaginosis and its association with genital micro-organisms in asymptomatic women

Introduction. Bacterial vaginosis (BV) is dysbiosis associated with an increased risk of several sexually transmitted infections. It is primarily diagnosed via Gram staining, although molecular analyses have presented higher diagnostic accuracy.Aim. This study aimed to evaluate the molecular epidemiology of BV in asymptomatic women to determine its association with several commensal and pathogenic micro-organisms of the genitalia.Methodology. The prevalence of BV was investigated through semiquantitative assessment of 201 women recruited during their routine gynaecological inspection at an outpatient clinic in Tabasco, Mexico.Results. Women with BV showed an increased prevalence of Chlamydia trachomatis (P=0.021) and Mycoplasma hominis (P=0.001). Of the BV-associated micro-organisms, Gardnerella vaginalis was significantly associated with C. trachomatis (P=0.005) and/or Ureaplasma parvum (P=0.003), whereas Atopobium vaginae and Megasphaera type 1 correlated significantly with Mycoplasma hominis (P=0.001). No significant association was observed between human papillomavirus (HPV) infection and BV, although there was increased prevalence of HPV59, HPV73, HPV52 and HPV58 in women displaying cervical cytological abnormalities.Conclusion. Identification of BV-associated micro-organisms via molecular analysis may help to distinguish recurrent cases from new infections and identify micro-organisms potentially associated with pharmacological resistance.

HPV18 E1 Protein Plus α-Galactosylceramide Elicit in Mice CD8+ T Cell Cross-Reactivity Against Cells Expressing E1 from Diverse Human Papillomavirus Types

CD8⁺ T cell immune response plays a critical role in the clearance of human papillomavirus (HPV)-infected cells. During the natural history of HPV infection, the E1 protein, an early-expressed helicase highly conserved among papillomaviruses, is involved in the replication of HPV genomes. We have previously shown, in a murine model, that immunization with HPV18 E1 protein combined with α-galactosylceramide elicits a specific CD8⁺ T cell response. We further proved those findings by analyzing whether CD8⁺ T cells from mice immunized with α-galactosylceramide plus HPV18 E1 protein could have a cytotoxic effect on cells expressing the carboxyl-terminal domain from the E1 proteins of other HPV types. Interestingly, CD8⁺ T cells raised against HPV18 E1 antigen presented cross-reactivity against the E1 protein from HPV53, 33, 16, and 31. Poor cross-reactivity was observed for HPV11, and none for HPV6. This outcome may be relevant for the design of broad-spectrum immune-protective agents against HPV infections.

The inoculation of α-Galactosylceramide and HPV18-E1 protein promote a cytokines profile involved in the generation of central memory CD8 + T cells

CD8+ mediated immune response plays a major role in the clearance of Human Papillomavirus (HPV) infected cells. In the natural history of an HPV infection, the expression of HPV-E1 helicase during viral replication makes it a potential immunological target. Currently, there are no therapeutic vaccines that eliminate the lesions caused by HPV. Nevertheless, there are many studies on developing therapeutic vaccines against HPV. Vaccines and immunological therapies mostly use adjuvants, particularly α-galactocilceramide (α-GalCer) is an adjuvant that promotes a CD8+ T lymphocyte response mainly.

We demonstrate in previous work, that immunization of HPV type 18 E1 protein along with α-GalCer adjuvant elicited CD8 T cell-immune response, able to eliminate tumor cells expressing HPV18 E1 protein.

In this study, we analyzed the effect of α-GalCer in the generation of memory T CD8+ populations. We evaluated the serum levels of IL-15, IL-7, IL-4, IL-31, IL-2, TNF-α and the number of memory CD8+ T cells.

The serum levels of IL-15, IL-7, IL-4 and TNF- α are increase in mice inoculated with α-GalCer plus HPV18-E1 with respect to mice inoculated with α-GalCer or HPV18-E1 protein. These data correlate with the increase of central memory T CD8+ population in mice inoculated with α-GalCer plus HPV18-E1.

These data indicate that the administration of α-GalCer along with HPV18-E1 protein helps the generation of central memory CD8 + T lymphocytes. This adjuvant could be useful in the development of new therapeutic strategies to clearance HPV established infections.

INCAN: (017/076/17) (CEI/1076/17)

Reprogramming of Energy Metabolism in Response to Radiotherapy in Head and Neck Squamous Cell Carcinoma

Head and neck cancer (HNC) is the sixth cause of cancer-related death worldwide. Head and neck squamous cells carcinoma (HNSCC) is the most frequent subtype of HNC. The development of HNSCC is associated to alcohol consumption, smoking or infection by high-risk human Papillomavirus (HR-HPV). Although the incidence of cancers associated with alcohol and tobacco has diminished, HNSCC associated with HR-HPV has significantly increased in recent years. However, HPV-positive HNSCC responds well to treatment, which includes surgery followed by radiation or chemoradiation therapy. Radiation therapy (RT) is based on ionizing radiation (IR) changing cell physiology. IR can directly interact with deoxyribonucleic acid (DNA) or produce reactive oxygen and nitrogen species (RONS), provoking DNA damage. When DNA damage is not repaired, programmed cell death (apoptosis and/or autophagy) is induced. However, cancer cells can acquire resistance to IR avoiding cell death, where reprogramming of energy metabolism has a critical role and is intimately connected with hypoxia, mitochondrial physiology, oxidative stress (OS) and autophagy. This review is focused on the reprogramming of energy metabolism in response to RT in HPV-positive and HPV-negative HNSCC, showing their differences in cellular metabolism management and the probable direction of treatments for each subtype of HNSCC.

Vaccination with human papillomavirus-18 E1 protein plus α-galactosyl-ceramide induces CD8+ cytotoxic response and impairs the growth of E1-expressing tumors

CD8+ T cell-mediated immune response plays a major role in the clearance of virus-infected cells, including human papillomavirus (HPV). The effective treatment of women with normal cytology but persistent high risk-HPV infection or with low-grade intraepithelial lesions could take advantage of novel strategies based on vaccination with viral immunological targets with a wide spectrum of cross-protection. The helicase E1, expressed early during viral replication in HPV infection, is among the most conserved papillomavirus proteins, which makes it a good vaccine candidate. In the present study, we examined E1-specific CD8+ T cell and NK immune responses in a mouse model with α-galactosylceramide (α-GalCer) as an adjuvant. We found that mice immunized with E1 combined with α-GalCer elicited an E1-specific CD8+ T and NK cell cytotoxic responses, which correlated with growth inhibition of grafted melanoma B16-F0 cells expressing E1, both in prophylactic and therapeutic protocols.

The Human Papillomavirus (HPV) E6 Oncoprotein Regulates CD40 Expression via the AT-Hook Transcription Factor AKNA

Persistent infection with high-risk Human Papillomavirus (HR-HPV) is the main requisite for cervical cancer development. Normally, HPV is limited to the site of infection and regulates a plethora of cellular elements to avoid the immune surveillance by inducing an anti-inflammatory state, allowing the progress through the viral cycle and the carcinogenic process. Recent findings suggest that the AT-hook transcriptional factor AKNA could play a role in the development of cervical cancer. AKNA is strongly related to the expression of co-stimulatory molecules such CD40/CD40L to achieve an anti-tumoral immune response. To date, there is no evidence demonstrating the effect of the HPV E6 oncoprotein on the AT-hook factor AKNA. In this work, minimal expression of AKNA in cervical carcinoma compared to normal tissue was found. We show the ability of E6 from high-risk HPVs 16 and 18 to interact with and down-regulate AKNA as well as its co-stimulatory molecule CD40 in a proteasome dependent manner. We also found that p53 interacts with AKNA and promotes AKNA expression. Our results indicate that the de-regulation of CD40 and AKNA is induced by the HPV E6 oncoprotein, and this event involves the action of p53 suggesting that the axis E6/p53A/AKNA might play an important role in the de-regulation of the immune system during the carcinogenic process induced by HR-HPV.

Oncolytic Viruses for Canine Cancer Treatment

Oncolytic virotherapy has been investigated for several decades and is emerging as a plausible biological therapy with several ongoing clinical trials and two viruses are now approved for cancer treatment in humans. The direct cytotoxicity and immune-stimulatory effects make oncolytic viruses an interesting strategy for cancer treatment. In this review, we summarize the results of in vitro and in vivo published studies of oncolytic viruses in different phases of evaluation in dogs, using PubMed and Google scholar as search platforms, without time restrictions (to date). Natural and genetically modified oncolytic viruses were evaluated with some encouraging results. The most studied viruses to date are the reovirus, myxoma virus, and vaccinia, tested mostly in solid tumors such as osteosarcomas, mammary gland tumors, soft tissue sarcomas, and mastocytomas. Although the results are promising, there are issues that need addressing such as ensuring tumor specificity, developing optimal dosing, circumventing preexisting antibodies from previous exposure or the development of antibodies during treatment, and assuring a reasonable safety profile, all of which are required in order to make this approach a successful therapy in dogs.

Deregulation of the Notch pathway as a common road in viral carcinogenesis

The Notch pathway is a conserved signaling pathway and a form of direct cell-cell communication related to many biological processes during development and adulthood. Deregulation of the Notch pathway is involved in many diseases, including cancer. Almost 20% of all cancer cases have an infectious etiology, with viruses responsible for at least 1.5 million new cancer cases per year. Seven groups of viruses have been classified as oncogenic: hepatitis B and C viruses (HBV and HCV respectively), Epstein-Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV), human T lymphotropic virus (HTLV-1), human papillomavirus (HPV), and Merkel cell polyomavirus (MCPyV). These viruses share the ability to manipulate a variety of cell pathways that are critical in proliferation and differentiation, leading to malignant transformation. Viral proteins interact directly or indirectly with different members of the Notch pathway, altering their normal function. This review focuses exclusively on the direct interactions of viral oncoproteins with Notch elements, providing a deeper understanding of the dual behavior of the Notch pathway as activator or suppressor of neoplasia in virus-related cancers.

Regulation of Cellular Metabolism by High-Risk Human Papillomaviruses

The alteration of glucose metabolism is one of the first biochemical characteristics associated with cancer cells since most of these cells increase glucose consumption and glycolytic rates even in the presence of oxygen, which has been called &ldquo;aerobic glycolysis” or the Warburg effect. Human papillomavirus (HPV) is associated with approximately 5% of all human cancers worldwide, principally to cervical cancer. E6 and E7 are the main viral oncoproteins which are required to preserve the malignant phenotype. These viral proteins regulate the cell cycle through their interaction with tumor suppressor proteins p53 and pRB, respectively. Together with the viral proteins E5 and E2, E6 and E7 can favor the Warburg effect and contribute to radio- and chemoresistance through the increase in the activity of glycolytic enzymes, as well as the inhibition of the Krebs cycle and the respiratory chain. These processes lead to a fast production of ATP obtained by Warburg, which could help satisfy the high energy demands of cancer cells during proliferation. In this way HPV proteins could promote cancer hallmarks. However, it is also possible that during an early HPV infection, the Warburg effect could help in the achievement of an efficient viral replication.

HPV18 E1-antigen specific CD8+ T cells show cross-reactivity against cells expressing E1 from HPV16, 31, 33 and 53

CD8+ mediated immune response plays a major role in the clearance of Human Papillomavirus (HPV) infected cells. Although HPV vaccines prevent HPV infections through humoral response, they do not protect against established infections and its cross protection is limited. In the HPV infection, the expression of E1 helicase during viral replication makes it a potential immunological target. The E1 protein is one of the most conserved proteins among papillomaviruses. We demonstrate in previous work, that immunization of HPV type 18 E1 protein plus α-GalactosylCeramide (α-GalCer) elicited CD8 T cell-immune response, able to eliminate tumor cells expressing HPV18 E1 protein. For this study, we analyzed the amino acids sequence of E1carboxi-terminal (CT) domains from HPV18, 16, 31, 33 and 53, using Rankpep and Clustal software to determine the number of conserved peptides among E1 proteins. These sequences share 20 predicted peptides. We cloned E1-CT domains of HPV16, 31, 33 and 53, and its expression in B16-F0 cells was determine. We show that CD8 T cells from mice immunized with HPV18 E1 protein plus α-GalCer, are actively cytotoxic in co-culture with B16-F0 cells expressing different E1-CT proteins in comparison with unimmunized mice, showing a cross-reactivity. Cytotoxicity activity was evaluated by detection of CD107a and CD107b on the CD8 T cells surface as part of cytotoxic granule exocytosis, through flow cytometry. Ongoing experiments will examine if mice immunized with HPV18 E1 protein plus α-GalCer are able to eliminate tumors cells expressing different E1-CT proteins in a mouse model. The characterization of new immunological targets against HPV, could help to develop new strategies to clearance HPV established infections.

Type-specific persistence and clearance rates of HPV genotypes in the oral and oropharyngeal mucosa in an HIV/AIDS cohort

BACKGROUND

Oral high-risk human papillomavirus (HR-HPV) infections are frequent and persistent among the HIV-positive population and are associated with an increased risk for head and neck cancer (HNC). In this study, we sought to determine the incidence, persistence and clearance of HPV infections in oral and oropharyngeal samples from HIV/AIDS subjects.

METHODS

A longitudinal, observational and analytical study was performed with an ongoing cohort of HIV/AIDS subjects in Mexico City (September 2013-February 2015). The study was approved by institutional committees, and demographic and clinical data were registered. At the baseline and three-month visits, oral examinations and cytobrush samples were obtained. DNA was purified, quantified and used to detect an HPV-L1 gene fragment by nested PCR, using MY09/MY11 and GP5 + /GP6 + primers. HPV DNA products were purified, sequenced and typed according to HPV databases. Risk factors were assessed, and a multivariate modelling approach was used to determine independent effects.

RESULTS

This study included 97 HIV/AIDS individuals (91% men [86.4% of which are men who have sex with men], median age: 36 years, 72.2% under HAART). From the baseline visit, HPV was observed in 55.7% (HR-HPV: 26.8%; HPV-18: 24.1%), with a higher HPV-positive samples for smokers (61.1 vs 32.6%, P = .005). The three-month overall HPV incidence was 33.9%; type-specific HPV persistence was 33.3% (HR-HPV: 13.3%); and 13 of the 33 (39.4%) baseline HPV-positive individuals cleared the infection (HR-HPV: 53.8%).

CONCLUSIONS

Although HR-HPV persistence was low, and clearance of the infection was observed in most cases, a close follow-up is necessary, given the increase in HNC among HIV-subjects, particularly HPV-related cancer.

The Role of E6 Spliced Isoforms (E6*) in Human Papillomavirus-Induced Carcinogenesis

Persistent infections with High Risk Human Papillomaviruses (HR-HPVs) are the main cause of cervical cancer development. The E6 and E7 oncoproteins of HR-HPVs are derived from a polycistronic pre-mRNA transcribed from an HPV early promoter. Through alternative splicing, this pre-mRNA produces a variety of E6 spliced transcripts termed E6*. In pre-malignant lesions and HPV-related cancers, different E6/E6* transcriptional patterns have been found, although they have not been clearly associated to cancer development. Moreover, there is a controversy about the participation of E6* proteins in cancer progression. This review addresses the regulation of E6 splicing and the different functions that have been found for E6* proteins, as well as their possible role in HPV-induced carcinogenesis.

Human Papillomavirus Types 16 and 18 Early-expressed Proteins Differentially Modulate the Cellular Redox State and DNA Damage

Oxidative stress has been proposed as a risk factor for cervical cancer development. However, few studies have evaluated the redox state associated with human papillomavirus (HPV) infection. The aim of this work was to determine the role of the early expressed viral proteins E1, E2, E6 and E7 from HPV types 16 and 18 in the modulation of the redox state in an integral form. Therefore, generation of reactive oxygen species (ROS), concentration of reduced glutathione (GSH), levels and activity of the antioxidant enzymes catalase and superoxide dismutase (SOD) and deoxyribonucleic acid (DNA) damage, were analysed in epithelial cells ectopically expressing the viral proteins. Our research shows that E6 oncoproteins decreased GSH and catalase protein levels, as well as its enzymatic activity, which was associated with an increase in ROS production and DNA damage. In contrast, E7 oncoproteins increased GSH, as well as catalase protein levels and its activity, which correlated with a decrease in ROS without affecting DNA integrity. The co-expression of both E6 and E7 oncoproteins neutralized the effects that were independently observed for each of the viral proteins. Additionally, the combined expression of E1 and E2 proteins increased ROS levels with the subsequent increase in the marker for DNA damage phospho-histone 2AX (γH2AX). A decrease in GSH, as well as SOD2 levels and activity were also detected in the presence of E1 and E2, even though catalase activity increased. This study demonstrates that HPV early expressed proteins differentially modulate cellular redox state and DNA damage.

SOX2 as a New Regulator of HPV16 Transcription

Persistent infections with high-risk human papillomavirus (HPV) constitute the main risk factor for cervical cancer development. HPV16 is the most frequent type associated to squamous cell carcinomas (SCC), followed by HPV18. The long control region (LCR) in the HPV genome contains the replication origin and sequences recognized by cellular transcription factors (TFs) controlling viral transcription. Altered expression of E6 and E7 viral oncogenes, modulated by the LCR, causes modifications in cellular pathways such as proliferation, leading to malignant transformation. The aim of this study was to identify specific TFs that could contribute to the modulation of high-risk HPV transcriptional activity, related to the cellular histological origin. We identified sex determining region Y (SRY)-box 2 (SOX2) response elements present in HPV16-LCR. SOX2 binding to the LCR was demonstrated by in vivo and in vitro assays. The overexpression of this TF repressed HPV16-LCR transcriptional activity, as shown through reporter plasmid assays and by the down-regulation of endogenous HPV oncogenes. Site-directed mutagenesis revealed that three putative SOX2 binding sites are involved in the repression of the LCR activity. We propose that SOX2 acts as a transcriptional repressor of HPV16-LCR, decreasing the expression of E6 and E7 oncogenes in a SCC context.

Immunization with Human Papillomavirus type-18 E1 protein induce CD8+ T cells with cytotoxic activity against cells expressing E1 from HPV-11, 33 and 53

CD8+ mediated immune response plays a major role in the clearance of Human Papillomavirus (HPV) infected cells. Although HPV vaccines are effective in preventing HPV infections through humoral response, they fail to protect against some HPV types and established infections. In the natural history of an HPV infection, the expression of E1 helicase during viral replication makes it a potential immunological target. The early expressed E1 protein is one of the most conserved proteins among papillomaviruses. We demonstrate in previous work, that immunization of HPV type 18 E1 protein along with α-GalactosylCeramide (α-GalCer) adjuvant elicited CD8 T cell-immune response, able to eliminate tumor cells expressing HPV18 E1 protein. For this study, we compared the amino acids sequence of E1carboxi-terminal (CT) domain from HPV18, 6, 11, 16, 30, 31, 35, 45 and 53. The sequences have 60% of identity and preserve two motifs previously described for being common between many Helicase types. We cloned E1-CT domain of HPV11, HPV33 and HPV53, and its expression in B16-F0 cells was determine.

We show that CD8 T cells from mice immunized with HPV18 E1 protein plus α-GalCer, are actively cytotoxic in co-culture with B16-F0 cells expressing E1-CT of HPV11, HPV33 and HPV53 in comparison with unimmunized mice. Cytotoxicity activity was evaluated by detection of CD107a and CD107b on the surface of CD8 T cells as part of cytotoxic granule exocytosis. Ongoing experiments will examine if these CD8 T cells from mice immunized with HPV18 E1 protein plus α-GalCer are also actively cytotoxic in presence of other E1 HPV types.

The characterization of new immunological targets against HPV, could help to develop new strategies to clearance HPV established infections.

Interaction of the Human Papillomavirus E6 Oncoprotein with Sorting Nexin 27 Modulates Endocytic Cargo Transport Pathways

A subset of high-risk Human Papillomaviruses (HPVs) are the causative agents of a large number of human cancers, of which cervical is the most common. Two viral oncoproteins, E6 and E7, contribute directly towards the development and maintenance of malignancy. A characteristic feature of the E6 oncoproteins from cancer-causing HPV types is the presence of a PDZ binding motif (PBM) at its C-terminus, which confers interaction with cellular proteins harbouring PDZ domains. Here we show that this motif allows E6 interaction with Sorting Nexin 27 (SNX27), an essential component of endosomal recycling pathways. This interaction is highly conserved across E6 proteins from multiple high-risk HPV types and is mediated by a classical PBM-PDZ interaction but unlike many E6 targets, SNX27 is not targeted for degradation by E6. Rather, in HPV-18 positive cell lines the association of SNX27 with components of the retromer complex and the endocytic transport machinery is altered in an E6 PBM-dependent manner. Analysis of a SNX27 cargo, the glucose transporter GLUT1, reveals an E6-dependent maintenance of GLUT1 expression and alteration in its association with components of the endocytic transport machinery. Furthermore, knockdown of E6 in HPV-18 positive cervical cancer cells phenocopies the loss of SNX27, both in terms of GLUT1 expression levels and its vesicular localization, with a concomitant marked reduction in glucose uptake, whilst loss of SNX27 results in slower cell proliferation in low nutrient conditions. These results demonstrate that E6 interaction with SNX27 can alter the recycling of cargo molecules, one consequence of which is modulation of nutrient availability in HPV transformed tumour cells.

HPV-E1 protein immunization promotes anti-tumoral CTL immune response in C57BL-6 mice

Cellular immune response is the main immune response to eliminate human papillomavirus (HPV) infected cells. HPV vaccines are effective in preventing HPV infections through humoral response, but fail to protect against many HPV types and established infections. Approximately 15% of women infected with high risk HPV do not have an effective immune response.

In the natural history of HPV infection, the most conserved protein among human papillomavirus, helicase E1, is the first immunological target of HPV infected cells. Therefore, we characterized the cellular immune response against E1 protein in a mouse model.

Immunizations with E1 protein + αGalacsosyl Ceramide (αGalCer) promoted an E1-antigen specific CTL response in C57BL-6 mice. We measured a CD107a/b+Granzime-A kinetic to identify antigen specific populations through flow cytometry.

The anti-tumoral response is only present in those mice immunized along with the αGalCer adjuvant. Within the set of six mice, three of them did not have any tumors and the other three developed small tumors in comparison with the mice in the control group, which were not immunized. In conclusion, the E1-antigen specific CTL plays an important role against tumor growth expressing E1-Carboxyl terminal domain.

Prevalence of sexually transmitted pathogens associated with HPV infection in cervical samples in a Mexican population

Cervical cancer development has been mainly associated with persistent human papillomavirus (HPV) infections. However, HPV infection is unlikely to be sufficient to cause cervical cancer, and the contribution of other sexually transmitted infections (STIs) could be the determining factor for cervical lesion-progression. The aim of this study was to estimate the prevalence of STIs associated with HPV-positivity in 201 cervical samples from patients who underwent annual routine gynecological exams. The overall prevalence of STIs was 57.7%, and the most frequent infection was Ureaplasma spp (UP) (39.8%), followed by Gardnerella vaginalis (GV) (25.9%), α-HPV (18.4%), Chlamydia trachomatis (CT) (1.5%), and Mycoplasma genitalium (MG) (0.5%). The highest prevalence rate of multiple non-HPV infections was observed for the age-range 31-40; for papillomavirus infection, the age-range was 21-30. In normal cervical samples, HPV16 was the most prevalent genotype (24.3%), followed by genotypes 58 (13.5%) and 52 (10.8%). Intriguingly, HPV18 was not detected in the study population, and genotypes 52 and 58 were found exclusively in samples with abnormal cytology. Papillomavirus infection with oncogenic types was significantly associated with GV (P = 0.025) and strongly associated with multiple non-HPV pathogens (P = 0.002). The following variables correlated significantly with cytological diagnosis of low-grade squamous intraepithelial lesion (LSIL): GV (P = 0.028), multiple non-HPV infections (P = 0.001), and high-risk HPV positivity (P = 0.001). Epidemiological data from this study will contribute to the molecular detection of sexually transmitted pathogens from screening programs to identify those women who are at risk for developing cervical lesions.

Impact of human papillomavirus coinfections on the risk of high-grade squamous intraepithelial lesion and cervical cancer

OBJECTIVE

The molecular and epidemiologic effect of human papillomavirus (HPV) coinfections in the risk of developing cervical cancer is yet unclear. The aim of this study was to determine the frequency HPV coinfections at different stages of cervical lesions in the development of cervical cancer and the impact of HPV specific type interactions on high-grade squamous intraepithelial lesions (HSIL) and invasive cervical cancer (ICC) risk.

METHODS

HPV testing was performed in 931 cervical samples diagnosed as: negative for intraepithelial lesion or malignancy (NILM); low-grade squamous intraepithelial lesion (LSIL); HSIL; and ICC. For HPV detection and typing two sets of primers from the L1 region were used in the polymerase chain reaction method (PCR) (MY09/MY11/HMB01 and L1C1/L1C2.1/L1C2.2) and HPV type was determined by PCR product sequence. To look for multiple HPV infections, the E6 nested multiplex PCR method was performed in all DNA samples. Odds ratios were calculated as indexes of the strength of the association between the sample category (LSIL/NILM or ICC/HSIL) and the presence of a given viral combination.

RESULTS

In HPV positive samples, coinfections are as common in ICC/HSIL as in LSIL/NILM (47.12% and 40.17%, respectively). There is an increased risk to ICC/HSIL when multiple high-risk HPV types are present. The coinfection of HPV68 with HPV16 increases the risk of ICC/HSIL (OR=14.54, P=0.012, after multivariate adjustment), related to the presence of HPV16 or HPV68 alone.

CONCLUSIONS

These results sustain that specific HPV coinfections confer an increased risk to develop ICC/HSIL.

KCNH1 potassium channels are expressed in cervical cytologies from pregnant patients and are regulated by progesterone

Potassium voltage-gated channel, subfamily H (eag-related), member 1 (KCNH1) potassium channels are potential tumour markers and cancer therapeutic targets and are up-regulated by oestrogens and human papilloma virus (HPV) oncogenes. However, the role of KCNH1 in normal tissues is poorly understood, and its expression in pregnancy is unknown. We wondered whether KCNH1 channels are expressed in cervical cells from pregnant patients and whether progesterone (P4) regulates KCNH1. The association with HPV was also investigated. KCNH1 protein expression was studied by immunocytochemistry in liquid-based cervical cytologies; 93 samples were obtained from pregnant patients at different trimesters, and 15 samples were obtained from non-pregnant women (controls). The presence ofHPVwas studied by PCR with direct sequencing and nested multiplex PCR. HeLa cervical cancer cells were transfected with human progesterone receptor-B (PR-B) and treated with P4.KCNH1mRNA expression in these cultures was studied by real-time PCR. KCNH1 protein was detected in 100% of the pregnancy samples and in 26% of the controls. We found 18 pregnant patients infected with HPV and detected 14 types ofHPV. There was no association between the percentage of cells expressing KCNH1 and either the presence or type of HPV. P4induced KCNH1 mRNA and protein expression in cells transfected with human PR-B. No regulation of KCNH1 by P4was observed in non-transfected cells. We show for the first time the expression of an ion channel during human pregnancy at different trimesters and KCNH1 regulation by P4in human cells. These data raise a new research field for KCNH1 channels in human tissues.

Role of innate immunity against human papillomavirus (HPV) infections and effect of adjuvants in promoting specific immune response

During the early stages of human papillomavirus (HPV) infections, the innate immune system creates a pro-inflammatory microenvironment by recruiting innate immune cells to eliminate the infected cells, initiating an effective acquired immune response. However, HPV exhibits a wide range of strategies for evading immune-surveillance, generating an anti-inflammatory microenvironment. The administration of new adjuvants, such as TLR (Toll-like receptors) agonists and alpha-galactosylceramide, has been demonstrated to reverse the anti-inflammatory microenvironment by down-regulating a number of adhesion molecules and chemo-attractants and activating keratinocytes, dendritic (DC), Langerhans (LC), natural killer (NK) or natural killer T (NKT) cells; thus, promoting a strong specific cytotoxic T cell response. Therefore, these adjuvants show promise for the treatment of HPV generated lesions and may be useful to elucidate the unknown roles of immune cells in the natural history of HPV infection. This review focuses on HPV immune evasion mechanisms and on the proposed response of the innate immune system, suggesting a role for the surrounding pro-inflammatory microenvironment and the NK and NKT cells in the clearance of HPV infections.

The modulation of apoptosis by oncogenic viruses

Transforming viruses can change a normal cell into a cancer cell during their normal life cycle. Persistent infections with these viruses have been recognized to cause some types of cancer. These viruses have been implicated in the modulation of various biological processes, such as proliferation, differentiation and apoptosis. The study of infections caused by oncogenic viruses had helped in our understanding of several mechanisms that regulate cell growth, as well as the molecular alterations leading to cancer. Therefore, transforming viruses provide models of study that have enabled the advances in cancer research. Viruses with transforming abilities, include different members of the Human Papillomavirus (HPV) family, Hepatitis C virus (HCV), Human T-cell Leukemia virus (HTLV-1), Epstein Barr virus (EBV) and Kaposi’s Sarcoma Herpesvirus (KSHV).

Apoptosis, or programmed cell death, is a tightly regulated process that plays an important role in development and homeostasis. Additionally, it functions as an antiviral defense mechanism. The deregulation of apoptosis has been implicated in the etiology of diverse diseases, including cancer. Oncogenic viruses employ different mechanisms to inhibit the apoptotic process, allowing the propagation of infected and damaged cells. During this process, some viral proteins are able to evade the immune system, while others can directly interact with the caspases involved in apoptotic signaling. In some instances, viral proteins can also promote apoptosis, which may be necessary for an accurate regulation of the initial stages of infection.

Frequency and genotype distribution of multiple human papillomavirus infections in cancer of the head and neck in a Mexican population

OBJECTIVE

The aim of this study was to determine the frequency and genotype distribution of single and multiple human papillomavirus (HPV) infections in head and neck squamous cell carcinomas (HNSCCs) in a Mexican population and to assess their associations with smoking and drinking habits and clinicopathologic characteristics.

STUDY DESIGN

A cross-sectional study was performed on a sample of patients diagnosed with HNSCCs. Tumor DNA was amplified using polymerase chain reaction with HPV consensus and multiplex primers. The associations among HPV status, survival, and clinical characteristics were analyzed.

RESULTS

Sixteen of the 43 HNSCCs were HPV positive. HPV16 was the most prevalent type, with single infections present in 5 cases, whereas another 5 cases were combined with HPV56 infection. There was a significant association between HPV infection and oropharyngeal cancers. HPV positivity was associated with overall survival at a nearly significant P level of 0.06.

CONCLUSIONS

Our data support the importance of HPV infection in oropharyngeal cancer, with a trend toward higher survival in HPV-positive cases.