Asian-American variant of human papillomavirus 16 E6 promotes the Warburg effect and hypoxia-inducible factor 1 signalling under hypoxia / by Sean Cuninghame.

Infection with high-risk human papillomavirus (HPV) is responsible for nearly all cases of cervical cancer, as well as a significant fraction of other ano-genital and head and neck cancers. Specifically, HPV type 16 (HPV 16) causes the majority of cervical cancers attributed to HPV infection. Intratypic variation occurs within the HPV16 genome such that naturally occurring variants have been described that display variable risks in promoting cervical cancer. In particular, the Asian-American (AA) variant of HPV16 has been found to be a greater risk factor for the development and earlier onset of invasive cervical cancer than the European Prototype (EP). Keratinocytes transduced with the AA variant were previously shown to have increased levels of glycolytic enzymes, implying AAE6 may enhance the Warburg effect - the tendency of cancer cells to take up higher levels of glucose and metabolize it to lactate. Therefore, glucose consumption and lactate production were assessed in the context of these variants and AAE6 was found to enhance the Warburg effect. To elucidate the mechanism behind this shift in metabolism, the hypoxia-inducible factor 1 (HIF-1) pathway was investigated. HIF-1 is a heterodimeric transcription factor made up of [alpha symbol] and [beta symbol] subunits, and enhances the transcription of genes involved in the Warburg effect. Even under normoxic conditions, HIF-1 a is detectable in AAE6 cells, and its levels are higher in the nucleus than in EPE6 cells. A HIF-1-specific reporter assay found HIF-1 activity to be greater in AAE6 in comparison to EPE6 under hypoxia, a typical hallmark of the tumour microenvironment. Gene expression analysis found that the HIF-1 targets GLUTl and VEGF-A are induced to a greater degree in AAE6 cells exposed to hypoxia. Future studies can elucidate the functionality of HIF-1 in AAE6’s enhanced invasive potential via RNA-interference

Effect of sedation with inhaled anaesthetics on cognitive and psychiatric outcomes in critically ill adults: a systematic review protocol

Introduction The COVID-19 pandemic has renewed interest in the use of inhaled anaesthetics for sedation of ventilated critically ill patients. Preliminary data show that inhaled anaesthetics reduce lung inflammation, time to extubation and intensive care unit length of stay compared with intravenous sedatives. However, the impact of inhaled anaesthetics on cognitive and psychiatric outcomes is not well described in this setting. Randomised controlled trials are underway to establish if inhaled anaesthetics affect these and other patient and health system outcomes. Our aim is to summarise the known effects of inhaled sedatives on cognitive and psychiatric outcomes. Methods and analysis In this systematic review, we will use MEDLINE, EMBASE, and PsycINFO to identify studies from 1970 to 2021 that assessed cognitive and psychiatric outcomes in critically ill adult patients sedated with inhaled anaesthetics. We will include case series, observational and cohort studies and randomised controlled trials. We will exclude case studies due to the heterogeneity of reporting in these studies. For randomised controlled trials comparing inhaled to intravenous sedation, we will report cognitive and psychiatric outcomes for both study arms. Studies will be selected based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Data will be extracted using a standardised data extraction tool by two independent reviewers. Studies will be assessed for bias using the Cochrane risk of bias tool for randomised controlled trials, or the Newcastle-Ottawa Scale for cohort and case-control studies. Findings will be reported according to outcome and descriptive statistics will be used to illustrate findings in a narrative fashion. Ethics and dissemination The systematic review uses published data and therefore does not require ethics approval. Results will be disseminated via publication in peer-reviewed journals and presentation at conferences related to the field. PROSPERO registration number CRD42021236455

Functional variants of human papillomavirus type 16 demonstrate host genome integration and transcriptional alterations corresponding to their unique cancer epidemiology

BACKGROUND: Human papillomaviruses (HPVs) are a worldwide burden as they are a widespread group of tumour viruses in humans. Having a tropism for mucosal tissues, high-risk HPVs are detected in nearly all cervical cancers. HPV16 is the most common high-risk type but not all women infected with high-risk HPV develop a malignant tumour. Likely relevant, HPV genomes are polymorphic and some HPV16 single nucleotide polymorphisms (SNPs) are under evolutionary constraint instigating variable oncogenicity and immunogenicity in the infected host. RESULTS: To investigate the tumourigenicity of two common HPV16 variants, we used our recently developed, three-dimensional organotypic model reminiscent of the natural HPV infectious cycle and conducted various “omics” and bioinformatics approaches. Based on epidemiological studies we chose to examine the HPV16 Asian-American (AA) and HPV16 European Prototype (EP) variants. They differ by three non-synonymous SNPs in the transforming and virus-encoded E6 oncogene where AAE6 is classified as a high- and EPE6 as a low-risk variant. Remarkably, the high-risk AAE6 variant genome integrated into the host DNA, while the low-risk EPE6 variant genome remained episomal as evidenced by highly sensitive Capt-HPV sequencing. RNA-seq experiments showed that the truncated form of AAE6, integrated in chromosome 5q32, produced a local gene over-expression and a large variety of viral-human fusion transcripts, including long distance spliced transcripts. In addition, differential enrichment of host cell pathways was observed between both HPV16 E6 variant-containing epithelia. Finally, in the high-risk variant, we detected a molecular signature of host chromosomal instability, a common property of cancer cells. CONCLUSIONS: We show how naturally occurring SNPs in the HPV16 E6 oncogene cause significant changes in the outcome of HPV infections and subsequent viral and host transcriptome alterations prone to drive carcinogenesis. Host genome instability is closely linked to viral integration into the host genome of HPV-infected cells, which is a key phenomenon for malignant cellular transformation and the reason for uncontrolled E6 oncogene expression. In particular, the finding of variant-specific integration potential represents a new paradigm in HPV variant biology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-016-3203-3) contains supplementary material, which is available to authorized users