Biology subjects

Morgan, E. L.

Publications and source records attributed to Morgan, E. L..

10 recordsLinked to original sources

bioRxiv2026

The HPV E7 oncoprotein promotes LIM and SH3 Domain Protein 1 (LASP1) transcription via the Rb/E2F1 signalling pathway in HPV-positive cervical cancer cells

Since its discovery in a metastatic lymph node in breast cancer patients, LIM and SH3 Domain Protein (LASP1) has been shown to be over-expressed in and promote the progression of various cancers. We recently demonstrated that LASP1 is highly expressed in human Papillomavirus positive (HPV+) cervical cancers where it promotes cell proliferation and invasion. Importantly, we showed that the HPV E7 oncoprotein increased LASP1 expression by downregulating the microRNA miR-203, which directly targets the LASP1 mRNA 3UTR. However, whether LASP1 is regulated by other mechanisms in HPV+ cervical cancers is unclear. Here, we demonstrate an additional mechanism by which HPV E7 regulates LASP1 transcription. Our data demonstrates an important the role for Rb/E2F1 signalling in promoting LASP1 expression in HPV+ cervical cancer cells. Mechanistically, E7-mediated Rb binding and degradation is required for E7-driven LASP1 promoter activity. Overexpression of Rb decreased LASP1 promoter activity, LASP1 mRNA expression and LASP1 protein levels, whereas E2F1 expression promoted LASP1 expression. Importantly, E2F1 directly bound to the LASP1 promoter region and the E2F1 binding sites are essential for LASP1 expression in HPV+ cervical cancer cells. Finally, we demonstrate that LASP1 can partially rescue the growth defects observed in E2F1 knockdown cervical cancer cells. Taken together, our data show that HPV E7 regulates LASP1 expression via the Rb/E2F1 signalling pathway. In combination with our previous work, our studies demonstrate that HPV E7 employs multiple mechanisms to drive LASP1 expression, reinforcing the importance of LASP1 in HPV+ cervical cancer.

cancer biology↗

bioRxiv2025

Diversity of motility gene signatures distinguishes commensal Clostridiathat elicit divergent host immune responses

Adaptive immune responses to commensal flagellins are hallmarks of Crohns disease, but it is unclear whether flagellins themselves promote inflammation or whether flagellated commensals can also be colitogenic. Here, we show that the arrangement of motility loci and the diversity of encoded flagellins can separate flagellated gut-derived Clostridia into at least 2 functionally distinct groups. In gnotobiotic mice, both groups induce tolerogenic responses but only one group promoted tissue inflammation following barrier disruption. Accordingly, specific flagellins expressed by members of this pro-inflammatory group displayed a heightened capacity for TLR5 activation which could be altered by modification of a defined region of the flagellin D0 domain. Finally, bacteria belonging to the pro-inflammatory group were found to be elevated in Crohns disease biopsies. Collectively, our study identified key features of specific commensal bacteria that possess colitogenic potential and revealed one mechanism whereby these organisms can potentially initiate intestinal inflammation.

immunology↗

bioRxiv2024

Velocity-selective arterial spin labelling bolus duration measurements: Implications for consensus recommendations

Velocity-selective arterial spin labelling (VSASL) MRI is insensitive to arterial transit time. This is an advantage over other perfusion measurements, where long arterial transit times can lead to bias. Therefore, VSASL can be used to study perfusion in the presence of long arterial transit times, such as in the ageing brain, in vascular pathologies, and cancer, or where arterial transit time changes, such as during measurement of cerebrovascular reactivity (CVR). However, when calculating perfusion (cerebral blood flow, CBF, in the brain) from VSASL signal, it is assumed that images are acquired before the trailing edge of the labelled blood has arrived in the imaging slice. The arrival of the trailing edge of the labelled bolus of blood will cause an underestimation of perfusion. Here we measure bolus duration in young, healthy human brains, both at rest and during elevated CBF. Grey matter bolus duration was 1.61 {+/-} 0.31 s, but there was a large spatial heterogeneity, with bolus duration being lower in anterior brain regions, with some areas having bolus duration < 1.2 s. We place these results in context of recommendations from a recent consensus paper, which recommends imaging 1.4 s after the label, potentially underestimating CBF in anterior regions. Further, we observed a 0.23 {+/-} 0.12 s reduction in grey matter bolus duration with 5% CO2 inhalation. These results can be used to inform the experimental design of future VSASL studies, to avoid underestimating perfusion by imaging after the arrival of the trailing edge of the labelled bolus.

neuroscience↗

bioRxiv2024

E7-mediated repression of miR-203 promotes LASP1-dependent proliferation in HPV-positive cervical cancer

Human papillomaviruses (HPV) are a major cause of malignancy, contributing to [~]5% of all human cancers worldwide, including most cervical cancer cases and a growing number of ano-genital and oral cancers. The major HPV viral oncogenes, E6 and E7, manipulate many host cellular pathways that promote cell proliferation and survival, predisposing infected cells to malignant transformation. Despite the availability of highly effective vaccines, there are still no specific anti-viral therapies targeting HPV or treatments for HPV-associated cancers. As such, a better understanding of viral-host interactions may allow the identification of novel therapeutic targets. Here, we demonstrate that the actin-binding protein LASP1 is upregulated in cervical cancer and significantly correlates with a poorer overall survival. In HPV positive cervical cancer, LASP1 depletion significantly inhibited proliferation in vitro, whilst having minimal effects in HPV negative cervical cancer cells. Furthermore, we show that the LASP1 SH3 domain is essential for LASP1-mediated proliferation in these cells. Mechanistically, we show that HPV E7 regulates LASP1 at the post-transcriptional level by repressing the expression of miR-203, which negatively regulated LASP1 mRNA levels by binding to its 3UTR. Finally, we demonstrated that LASP1 expression is required for the growth of HPV positive cervical cancer cells in an in vivo tumourigenicity model. Together, these data demonstrate that HPV induces LASP1 expression to promote proliferation and survival role in cervical cancer, thus identifying a potential therapeutic target in these cancers.

cancer biology↗

bioRxiv2023

The virus-encoded ion channel "viroporin" activity of the agnoprotein is required for BK Polyomavirus release from infected kidney cells

BK polyomavirus (BKPyV) is a common opportunistic pathogen and the causative agent of several diseases in transplant patients and the immunosuppressed. Despite its importance, aspects of the virus lifecycle such as how the virus exits an infected cells, remain poorly understood. The late region of the BKPyV genome encodes an auxillery protein called agnoprotein. We and others have shown that agnoprotein is an essential factor in virus release, and the loss of agnoprotein results in an accumulation of virus particles within the nucleus of an infected cell. The functions of agnoprotein necessary for this egress phenotype are not known. Here we demonstrate that agnoprotein shows properties associated with viroporins, a group of virus-encoded membrane spanning proteins that play key roles in virus infection and release. We demonstrate that agnoprotein oligomerises and perturbs membranes in cells. The development of a novel recombinant agnoprotein expression system permitted the identification of the first small molecules targeting agnoprotein. These compounds abrogated agnoprotein viroporin activity in vitro and reduced virus release, indicating that viroporin activity contributes to the phenotype observed in agnoprotein knockout viruses. The identification of channel activity should enhance the future understanding of the physiological function of agnoprotein and could represent an important target for antiviral intervention.

microbiology↗

bioRxiv2022

Exploitation of ATP-sensitive potassium ion (KATP) channels by HPV promotes cervical cancer cell proliferation by contributing to MAPK/AP-1 signalling

Persistent infection with high-risk human papillomaviruses (HPVs) is the causal factor in multiple human malignancies, including >99% of cervical cancers and a growing proportion of oropharyngeal cancers. Prolonged expression of the viral oncoproteins E6 and E7 is necessary for transformation to occur. Although some of the mechanisms by which these oncoproteins contribute to carcinogenesis are well-characterised, a comprehensive understanding of the signalling pathways manipulated by HPV is lacking. Here, we present the first evidence to our knowledge that the targeting of a host ion channel by HPV can contribute to cervical carcinogenesis. Through the use of pharmacological activators and inhibitors of ATP-sensitive potassium ion (KATP) channels, we demonstrate that these channels are active in HPV-positive cells and that this activity is required for HPV oncoprotein expression. Further, expression of SUR1, which forms the regulatory subunit of the multimeric channel complex, was found to be upregulated in both HPV+ cervical cancer cells and in samples from patients with cervical disease, in a manner dependent on the E7 oncoprotein. Importantly, knockdown of SUR1 expression or KATP channel inhibition significantly impeded cell proliferation via induction of a G1 cell cycle phase arrest. This was confirmed both in vitro and in in vivo tumourigenicity assays. Mechanistically, we propose that the pro-proliferative effect of KATP channels is mediated via the activation of a MAPK/AP-1 signalling axis. A complete characterisation of the role of KATP channels in HPV-associated cancer is now warranted in order to determine whether the licensed and clinically available inhibitors of these channels could constitute a potential novel therapy in the treatment of HPV-driven cervical cancer.

microbiology↗

bioRxiv2020

Combining Natural Language Processing and Metabarcoding to Reveal Pathogen-Environment Associations

Cryptococcus neoformans is responsible for life-threatening infections that primarily affect immunocompromised individuals and has an estimated worldwide burden of 220,000 new cases each year--with 180,000 resulting deaths--mostly in sub-Saharan Africa. Surprisingly, little is known about the ecological niches occupied by C. neoformans in nature. To expand our understanding of the distribution and ecological associations of this pathogen we implement a Natural Language Processing approach to better describe the niche of C. neoformans. We use a Latent Dirichlet Allocation model to de novo topic model sets of metagenetic research articles written about varied subjects which either explicitly mention, inadvertently find, or fail to find C. neoformans. These articles are all linked to NCBI Sequence Read Archive datasets of 18S ribosomal RNA and/or Internal Transcribed Spacer gene-regions. The number of topics was determined based on the model coherence score, and articles were assigned to the created topics via a Machine Learning approach with a Random Forest algorithm. Our analysis provides support for a previously suggested linkage between C. neoformans and soils associated with decomposing wood. Our approach, using a search of single-locus metagenetic data, gathering papers connected to the datasets, de novo determination of topics, the number of topics, and assignment of articles to the topics, illustrates how such an analysis pipeline can harness large-scale datasets that are published/available but not necessarily fully analyzed, or whose metadata is not harmonized with other studies. Our approach can be applied to a variety of systems to assert potential evidence of environmental associations. Author SummaryOur finding that C. neoformans is associated with decomposing wood is reinforced by the general literature on C. neoformans and its close congeneric relatives and warrants further investigation. This work demonstrates the potential utility of pairing Natural Language Processing (NLP) with single-locus metagenetic data for the study of Neglected Tropical Diseases. We present a novel method to study the ecological niches of rare pathogens that leverages the immense amount of data available to researchers in the NCBI Sequence Read Archive (SRA)combined with a text-mining analysis based on Natural Language Processing. We demonstrate that text processing, noun identification, and verb identification can play an important role in analyzing a large corpus of documents together with metagenetic data. Forging this connection requires access to all of the available ecological 18S ribosomal RNA and Internal Transcribed Spacer NCBI SRA datasets. These datasets use metabarcoding to query taxonomic diversity in eukaryotic organisms, and in the case of the Internal Transcribed Spacer, they specifically target Fungi. The presence of specific species is inferred when diagnostic 18S or ITS gene region sequences are found in the SRA data. We searched for C. neoformans in all 18S and ITS datasets available and gathered all associated journal articles that either cite the SRA data accessions or are cited in the SRA data accessions. Published metagenetic data often have associated metadata including: latitude and longitude, temperature, and other physical characteristics describing the conditions in which the metagenetic sample was collected. These metadata are not always be presented in consistent formats, so harmonizing study methods may be needed to appropriately compare metagenetic data as commonly required in metanalysis studies. We present an analysis which takes as input articles associated with SRA datasets that were found to contain evidence of C. neoformans. We apply NLP methods to this corpus of articles to describe the niche of C. neoformans. Our results reinforce the current understanding of C. neoformanss niche, indicating the pertinence of employing a NLP analysis to identify the niche of an organism. This approach could further the description of virtually any other organism that routinely appears in metagenetic surveys, especially pathogens, whose ecological niches are unknown or poorly understood. Optional Striking Image O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/280578v1_ufig1.gif" ALT="Figure 1"> View larger version (66K): org.highwire.dtl.DTLVardef@135ce50org.highwire.dtl.DTLVardef@17bf52borg.highwire.dtl.DTLVardef@11cf682org.highwire.dtl.DTLVardef@7be6ea_HPS_FORMAT_FIGEXP M_FIG C_FIG Cryptococcus neoformans cells budding. Image Provided Courtesy of Felipe H. Santiago-Tirado, colored by Kristina Davis, CC-BY 4.0

bioinformatics↗

bioRxiv2020

The deubiquitinase (DUB) USP13 promotes Mcl-1 stabilisation in cervical cancer

Ubiquitination is a critical regulator of cellular homeostasis. Aberrations in the addition or removal of ubiquitin can result in the development of cancer and key components of the ubiquitination machinery serve as oncogenes or tumour suppressors. An emerging target in the development of cancer therapeutics are the deubiquitinase (DUB) enzymes that remove ubiquitin from protein substrates. Whether this class of enzyme plays a role in cervical cancer has not been fully explored. By interrogating the cervical cancer data from the TCGA consortium, we noted that the DUB USP13 is amplified in approximately 15% of cervical cancer cases. We confirmed that USP13 expression was increased in cervical cancer cell lines, cytology samples from patients with cervical disease and in cervical cancer tissue. Depletion of USP13 inhibited cervical cancer cell proliferation. Mechanistically, USP13 bound to, deubiquitinated and stabilised Mcl-1, a pivotal member of the anti-apoptotic Bcl-2 family and the reduced Mcl-1 expression contributed to the observed proliferative defect. Importantly, the expression of USP13 and Mcl-1 proteins correlated in cervical cancer tissue. Finally, we demonstrated that depletion of USP13 expression or inhibition of USP13 enzymatic activity increased the sensitivity of cervical cancer cells to the BH3 mimetic inhibitor ABT-263. Together, our data demonstrates that USP13 is a potential oncogene in cervical cancer that functions to stabilise the pro-survival protein Mcl-1, offering a potential therapeutic target for these cancers.

microbiology↗

bioRxiv2020

Werner syndrome protein (WRN) regulates cell proliferation and the human papillomavirus 16 life cycle during epithelial differentiation

Human papillomaviruses recruit a host of DNA damage response factors to their viral genome to facilitate homologous recombination replication in association with the viral replication factors E1 and E2. We previously demonstrated that SIRT1 deacetylation of WRN promotes recruitment of WRN to E1-E2 replicating DNA, and that WRN regulates both the levels and fidelity of E1-E2 replication. The deacetylation of WRN by SIRT1 results in an active protein able to complex with replicating DNA, but a protein that is less stable. Here we demonstrate an inverse correlation between SIRT1 and WRN in CIN cervical lesions when compared with normal control tissue, supporting our model of SIRT1 deacetylation destabilizing WRN protein. We CRISPR/Cas9 edited N/Tert-1 and N/Tert-1+HPV16 cells to knock out WRN protein expression and subjected the cells to organotypic raft cultures. In N/Tert-1 cells without WRN expression there was enhanced basal cell proliferation, DNA damage and thickening of the differentiated epithelium. In N/Tert-1+HPV16 cells, there was enhanced basal cell proliferation, increased DNA damage throughout the epithelium and increased viral DNA replication. Overall, the results demonstrate that the expression of WRN is required to control the proliferation of N/Tert-1 cells and controls the HPV16 life cycle in these cells. This complements our previous data demonstrating that WRN controls the levels and fidelity of HPV16 E1-E2 DNA replication. The results describe a new role for WRN, a tumor suppressor, in controlling keratinocyte differentiation and the HPV16 life cycle. ImportanceHPV16 is the major human viral carcinogen, responsible for around 3-4% of all cancers worldwide. Our understanding of how the viral replication machinery interacts with host factors to control/activate the DNA damage response to promote the viral life cycle remains incomplete. Recently, we demonstrated a SIRT1-WRN axis that controls HPV16 replication and here we demonstrate that this axis persists in clinical cervical lesions induced by HPV16. Here we describe the effects of WRN depletion on cellular differentiation with and without HPV16; WRN depletion results in enhanced proliferation and DNA damage irrespective of HPV16 status. Also, WRN is a restriction factor for the viral life cycle as replication is disrupted in the absence of WRN. Future studies will focus on enhancing our understanding of how WRN regulates viral replication. Our goal is to ultimately identify cellular factors essential for HPV16 replication that can be targeted for therapeutic gain.

molecular biology↗

bioRxiv2018

Autocrine STAT3 activation in HPV positive cervical cancer through a virus-driven Akt - NF?B - IL-6 signalling axis

Persistent human papillomavirus (HPV) infection is the leading cause of cervical cancer. Although the fundamental link between HPV infection and oncogenesis is established, the specific mechanisms of virus-mediated transformation remain poorly understood. We previously demonstrated that the HPV encoded E6 protein increases the activity of the proto-oncogenic transcription factor STAT3 in primary human keratinocytes; however, the molecular basis for STAT3 activation in cervical cancer remains unclear. Here, we show that STAT3 phosphorylation in HPV positive cervical cancer cells is mediated primarily via autocrine activation by the pro-inflammatory cytokine Interleukin 6 (IL-6). Antibody-mediated blockade of IL-6 signalling in HPV positive cells inhibits STAT3 phosphorylation, whereas both recombinant IL-6 and conditioned media from HPV positive cells leads to increased STAT3 phosphorylation within HPV negative cervical cancer cells. Interestingly, we demonstrate that non-conventional activation of the transcription factor NF{kappa}B, involving the protein kinase Akt, is required for IL-6 production and subsequent STAT3 activation. Our data provides new insights into the molecular re-wiring of cancer cells by HPV E6. We reveal that activation of an IL-6 signalling axis drives the autocrine and paracrine phosphorylation of STAT3 within HPV positive cervical cancers cells. Greater understanding of this pathway provides a potential opportunity for the use of existing clinically approved drugs for the treatment of HPV-mediated cervical cancer.\n\nAuthor SummaryPersistent infection with HPV is the predominant cause of anogenital and oral cancers. Transformation requires the re-wiring of signalling pathways in infected cells by virus encoded oncoproteins. At this point a comprehensive understanding of the full range of host pathways necessary for HPV-mediated carcinogenesis is still lacking. In this study we describe a signalling circuit resulting in the aberrant production of the IL-6 cytokine. Mediated by the HPV E6 oncoprotein, it requires activation of the NF{kappa}B transcription factor. The autocrine and paracrine actions of IL-6 are essential for STAT3 activation in HPV-positive cervical cancers. This study provides molecular insights into the mechanisms by which a virus encoded oncoprotein activates an oncogenic pathway, and illuminates potential targets for therapeutic intervention.

cancer biology↗