Critical Role of the Transcription Factor AKNA in T-Cell Activation: An Integrative Bioinformatics Approach

The human akna gene encodes an AT-hook transcription factor, the expression of which is involved in various cellular processes. The goal of this study was to identify potential AKNA binding sites in genes that participate in T-cell activation and validate selected genes. Here we analyzed ChIP-seq and microarray assays to determine AKNA-binding motifs and the cellular process altered by AKNA in T-cell lymphocytes. In addition, we performed a validation analysis by RT-qPCR to assess AKNA's role in promoting IL-2 and CD80 expression. We found five AT-rich motifs that are potential candidates as AKNA response elements. We identified these AT-rich motifs in promoter regions of more than a thousand genes in activated T-cells, and demonstrated that AKNA induces the expression of genes involved in helper T-cell activation, such as IL-2. The genomic enrichment and prediction of AT-rich motif analyses demonstrated that AKNA is a transcription factor that can potentially modulate gene expression by recognizing AT-rich motifs in a plethora of genes that are involved in different molecular pathways and processes. Among the cellular processes activated by AT-rich genes, we found inflammatory pathways potentially regulated by AKNA, suggesting AKNA is acting as a master regulator during T-cell activation.

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.

Fas and Fas ligand are highly expressed in lymphocytes from cervical intraepithelial neoplasia and cervical cancer patients: A possible role for immune escaping

Objectives

Infection with high-risk human papillomavirus is required to develop cervical cancer. Some viruses modulate the Fas/FasL signaling to evade the immune response; the role of these molecules in cervical cancer is not clear. In this study, we measured the expression levels of Fas and FasL mRNA, soluble proteins, and cell surface proteins in peripheral blood mononuclear cells from patients with low- and high-grade squamous intraepithelial lesions and cervical cancer in relation to healthy women, to gain new insights into the role of Fas/FasL in cervical cancer development.

Materials and Methods

Fas/FasL mRNA expression was measured in cervical tissues and peripheral blood mononuclear cells from patients and healthy subjects; serum soluble proteins Fas/FasL were measured by ELISA, and cell-surface protein expression was detected by flow cytometry.

Results

Varying expression levels were found for both molecules. Cervical Fas and FasL mRNA expression was decreased in low- and high-grade lesions, but it was increased in cervical cancer cases. While, systemic Fas mRNA expression increased as malignity progressed; systemic FasL mRNA expression was increased in low- and high-grade lesions, but it was decreased in cancer patients. Soluble FasL levels decreased as lesions progressed, while soluble Fas levels increased. Finally, overexpression of Fas/FasL on the surface of peripheral blood mononuclear cells was found in patients with low-grade lesion with respect to healthy donors.

Conclusion

Fas and FasL act as negative modulators of the immune response, probably by removing specific cytotoxic T lymphocytes against papillomavirus -infected cells and tumor cells.

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.

Functional Role of AKNA: A Scoping Review

Human akna encodes an AT-hook transcription factor whose expression participates in various cellular processes. We conducted a scoping review on the literature regarding the functional role of AKNA according to the evidence found in human and in vivo and in vitro models, stringently following the “PRISMA-ScR” statement recommendations. Methods: We undertook an independent PubMed literature search using the following search terms, AKNA OR AKNA ADJ gene OR AKNA protein, human OR AKNA ADJ functions. Observational and experimental articles were considered. The selected studies were categorized using a pre-determined data extraction form. A narrative summary of the evidence was produced. Results: AKNA modulates the expression of CD40 and CD40L genes in immune system cells. It is a negative regulator of inflammatory processes as evidenced by knockout mouse models and observational studies for several autoimmune and inflammatory diseases. Furthermore, AKNA contributes to the de-regulation of the immune system in cancer, and it has been proposed as a susceptibility genetic factor and biomarker in CC, GC, and HNSCC. Finally, AKNA regulates neurogenesis by destabilizing the microtubules dynamics. Conclusion: Our results provide evidence for the role of AKNA in various cellular processes, including immune response, inflammation, development, cancer, autoimmunity, and neurogenesis.

Biocide effect against SARS-CoV-2 and ESKAPE pathogens of a noncytotoxic silver-copper nanofilm

Nanometric materials with biocidal properties effective against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and pathogenic bacteria could be used to modify surfaces, reducing the risk of touching transmission. In this work, we showed that a nanometric layer of bimetallic AgCu can be effectively deposited on polypropylene (PP) fibers. The virucidal properties of the AgCu nanofilm were evaluated by comparing the viral loads remaining on uncoated and coated PP after contact times between 2 and 24 h. Quantification of virion numbers for different initial concentrations indicated a reduction of more than 95% after 2 h of contact. The bactericidal action of the AgCu nanofilm was also confirmed by inoculating uncoated and coated PP with a pool of pathogenic bacteria associated with pneumonia (ESKAPE). Meanwhile, no cytotoxicity was observed for human fibroblasts and keratinocyte cells, indicating that the nanofilm could be in contact with human skin without threat. The deposition of the AgCu nanofilm on the nonwoven component of reusable cloth masks might help to prevent virus and bacterial infection while reducing the pollution burden related to the disposable masks. The possible mechanism of biocide contact action was studied by quantum chemistry calculations that show that the addition of Ag and/or Cu makes the polymeric fiber a better electron acceptor. This can promote the oxidation of the phospholipids present at both the virus and bacterial membranes. The rupture at the membrane exposes and damages the genetic material of the virus. More studies are needed to determine the mechanism of action, but the results reported here indicate that Cu and Ag ions are good allies, which can help protect us from the virus that has caused this disturbing pandemic.

Comprehensive bioinformatic analysis reveals oncogenic role of H2A.Z isoforms in cervical cancer progression

Objectives

Cervical cancer ranks as the fourth most common neoplasia in women worldwide in which epigenetic alterations play an important role. Several studies have reported pro-oncogenic role of the histone variant H2A.Z in different types of cancer; however, the role of H2A.Z in cervical cancer remains poorly studied. This study aimed to determine the potential role of H2A.Z in cervical cancer through a bioinformatic approach.

Materials and Methods

H2A.Z expression was analyzed in The Human Protein Atlas, The Cancer Genome Atlas, and Gene Expression Omnibus datasets. The promoter regions of H2AZ1 and H2AZ2 genes were downloaded from Expasy, and the prediction of transcription factor binding motifs was performed using CONSITE, Alibaba, and ALGGEN. ChIP-seq and RNA-seq data from HeLa-S3 cells were downloaded from ENCODE. The discovery motif was investigated using MEME-ChIP. The functional annotation was examined in Enrich.

Results

The expression of H2A.Z is elevated in cervical cancer. Interestingly, DNA methylation, copy number, and transcription factors AP2α and ELK1 are involved in H2A.Z overexpression. Additionally, H2A.Z is enriched on promoter and enhancer regions of genes involved in pathways associated with cancer development. In these regions, H2A.Z enables the recruitment of transcription factors such as NRF1, NFYA, and RNA Pol II. Finally, H2A.Z allows the expression of genes associated with proliferation in patients with cervical cancer.

Conclusion

Our findings suggest that H2A.Z overexpression and its presence in promoters and enhancers could be regulating the transcription of genes involved in cervical carcinogenesis.

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.

IMMUNOLOGY OF CERVICAL CANCER

Optimal function of the immune system allows the recognition and elimination of infected and tumor cells. However, these cells can develop mechanisms to evade the cellular immune response. In human papillomavirus (HPV) infection, dysregulation of major histocompatibility complex Class I molecules and other components of the innate immune system promote the survival of infected cells by allowing the infection to persist which, in turn, favors the development of cancer. Further, tumor cells possess inherent mechanisms designed to block the recognition and activation of cytotoxic lymphocytes: particularly, HPV proteins such as E1 and E2 and oncoproteins E5, E6, and E7 that inhibit immune mechanisms and/or stimulate the expression of immunosuppressive cytokines. These mechanisms include a decrease in receptor activation and costimulating molecules on the surface of immune cells, as well as the constitutive expression of molecules that inhibit their function, which allow HPV persistence and tumor progression. Immunotherapy-based therapeutic options are positioned as excellent candidates for the treatment of cervical cancer.

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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.

High expression of Helicobacter pylori VapD in both the intracellular environment and biopsies from gastric patients with severity

Helicobacter pylori is a Gram-negative bacterium that causes chronic atrophic gastritis and peptic ulcers and it has been associated with the development of gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT). One of the more remarkable characteristics of H. pylori is its ability to survive in the hostile environment of the stomach. H. pylori regulates the expression of specific sets of genes allowing it to survive high acidity levels and nutrient scarcity. In the present study, we determined the expression of virulence associated protein D (VapD) of H. pylori inside adenocarcinoma gastric (AGS) cells and in gastric biopsies. Using qRT-PCR, VapD expression was quantified in intracellular H. pylori-AGS cell cultures at different time points and in gastric mucosa biopsies from patients suffering from chronic atrophic gastritis, follicular gastritis, peptic ulcers, gastritis precancerous intestinal metaplasia and adenocarcinoma. Our results show that vapD of H. pylori presented high transcription levels inside AGS cells, which increased up to two-fold above basal values across all assays over time. Inside AGS cells, H. pylori acquired a coccoid form that is metabolically active in expressing VapD as a protection mechanism, thereby maintaining its permanence in a viable non-cultivable state. VapD of H. pylori was expressed in all gastric biopsies, however, higher expression levels (p = 0.029) were observed in gastric antrum biopsies from patients with follicular gastritis. The highest VapD expression levels were found in both antrum and corpus gastric biopsies from older patients (>57 years old). We observed that VapD in H. pylori is a protein that is only produced in response to interactions with eukaryotic cells. Our results suggest that VapD contributes to the persistence of H. pylori inside the gastric epithelial cells, protecting the microorganism from the intracellular environment, reducing its growth rate, enabling long-term infection and treatment resistance.

Lactate in the Regulation of Tumor Microenvironment and Therapeutic Approaches

Tumor cells must generate sufficient ATP and biosynthetic precursors in order to maintain cell proliferation requirements. Otto Warburg showed that tumor cells uptake high amounts of glucose producing large volumes of lactate even in the presence of oxygen, this process is known as “Warburg effect or aerobic glycolysis.” As a consequence of such amounts of lactate there is an acidification of the extracellular pH in tumor microenvironment, ranging between 6.0 and 6.5. This acidosis favors processes such as metastasis, angiogenesis and more importantly, immunosuppression, which has been associated to a worse clinical prognosis. Thus, lactate should be thought as an important oncometabolite in the metabolic reprogramming of cancer. In this review, we summarized the role of lactate in regulating metabolic microenvironment of cancer and discuss its relevance in the up-regulation of the enzymes lactate dehydrogenase (LDH) and monocarboxilate transporters (MCTs) in tumors. The goal of this review is to expose that lactate is not only a secondary product of cellular metabolic waste of tumor cells, but also a key molecule involved in carcinogenesis as well as in tumor immune evasion. Finally, the possible targeting of lactate production in cancer treatment is discussed.

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.

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.

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.