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

2018 ◽  
Author(s):  
Ethan Luc Morgan ◽  
Andrew Macdonald
Keyword(s):  
Cervical Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Human Keratinocytes ◽  
Hpv Infection ◽  
Primary Human Keratinocytes ◽  
Hpv E6 ◽  
Stat3 Phosphorylation ◽  
Cervical Cancer Cells ◽  
Approved Drugs

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?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.

scholarly journals Optimisation of Folate-Mediated Liposomal Encapsulated Arsenic Trioxide for Treating HPV-Positive Cervical Cancer Cells In Vitro

2019 ◽  
Vol 20 (9) ◽  
pp. 2156 ◽  
Author(s):  
Akhtar ◽  
Ghali ◽  
Wang ◽  
Bell ◽  
Li ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Folic Acid ◽  
Cancer Cells ◽  
Arsenic Trioxide ◽  
Folate Receptor ◽  
Hpv Infection ◽  
Cytotoxicity Studies ◽  
Cervical Cancer Cells ◽  
Infected Cells

High-risk human papilloma virus (HPV) infection is directly associated with cervical cancer development. Arsenic trioxide (ATO), despite inducing apoptosis in HPV-infected cervical cancer cells in vitro, has been compromised by toxicity and poor pharmacokinetics in clinical trials. Therefore, to improve ATO’s therapeutic profile for HPV-related cancers, this study aims to explore the effects of length of ligand spacers of folate-targeted liposomes on the efficiency of ATO delivery to HPV-infected cells. Fluorescent ATO encapsulated liposomes with folic acid (FA) conjugated to two different PEG lengths (2000 Da and 5000 Da) were synthesised, and their cellular uptake was examined for HPV-positive HeLa and KB and HPV-negative HT-3 cells using confocal microscopy, flow cytometry, and spectrophotometer readings. Cellular arsenic quantification and anti-tumour efficacy was evaluated through inductively coupled plasma-mass spectrometry (ICP-MS) and cytotoxicity studies, respectively. Results showed that liposomes with a longer folic acid-polyethylene glycol (FA-PEG) spacer (5000 Da) displayed a higher efficiency in targeting folate receptor (FR) + HPV-infected cells without increasing any inherent cytotoxicity. Targeted liposomally delivered ATO also displayed superior selectivity and efficiency in inducing higher cell apoptosis in HPV-positive cells per unit of arsenic taken up than free ATO, in contrast to HT-3. These findings may hold promise in improving the management of HPV-associated cancers.

scholarly journals The Brn-3a transcription factor plays a key role in regulating the growth of cervical cancer cells in vivo

Oncogene ◽  
2001 ◽  
Vol 20 (35) ◽  
pp. 4899-4903 ◽  
Author(s):  
Daniel Ndisang ◽  
Vishwanie Budhram-Mahadeo ◽  
Barbara Pedley ◽  
David S Latchman
Keyword(s):  
Cervical Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cervical Cancer Cells

Inhibition of tumorigenicity of cervical cancer cells in nude mice by HPV e6-e7 anti-sense RNA

1992 ◽  
Vol 51 (5) ◽  
pp. 831-834 ◽  
Author(s):  
Magnus von Knebel Doeberitz ◽  
Claudia Rittmüller ◽  
Harald Zur Hausen ◽  
Matthias dürst
Keyword(s):  
Cervical Cancer ◽  
Cancer Cells ◽  
Nude Mice ◽  
Hpv E6 ◽  
Cervical Cancer Cells

scholarly journals The degradation of Rap1GAP via E6AP-mediated ubiquitin-proteasome pathway is associated with HPV16/18-infection in cervical cancer cells

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yinghui Wang ◽  
Yihang Xie ◽  
Boxuan Sun ◽  
Yuwei Guo ◽  
Ling Song ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Cells ◽  
Suppressor Gene ◽  
Hpv Infection ◽  
Degradation Pathway ◽  
Human Papillomaviruses ◽  
Siha Cells ◽  
Cervical Cancer Cells ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway

Abstract Background Cervical cancers are closely associated with persistent high-risk human papillomaviruses (HR HPV) infection. The main mechanism involves the targeting of tumor suppressors, such as p53 and pRB, for degradation by HR HPV-encoded oncoproteins, thereby leading to tumorigenesis. Rap1GAP, a tumor suppressor gene, is down-regulated in many cancers. Previous studies have revealed that down-regulation of Rap1GAP is correlated with HPV16/18 infection in cervical cancer. However, the molecular mechanism remains unclear. In this study, we aimed to address the degradation pathway of Rap1GAP in HPV-positive cervical cancer cells. Methods HPV-positive (HeLa and SiHa) and negative (C33A) cervical cancer cells were used to analyze the pathways of Rap1GAP degradation. MG132 (carbobenzoxy-leucyl-leucyl-leucine) was used to inhibit protein degradation by proteasome. Co-immunoprecipitation (co-IP) was used to detect the interaction between Rap1GAP and E6AP. siRNA for E6AP was used to silence the expression of E6AP. Rapamycin was used to induce cell autophagy. Western blotting was used to check the levels of proteins. Results Following treatment with MG132, the levels of Rap1GAP were increased in the HR HPV-positive HeLa and SiHa cells, but not in the HPV-negative C33A cells. Co-immunoprecipitation assay revealed ubiquitinated Rap1GAP protein in HeLa and SiHa cells, but not in C33A cells. E6-associated protein (E6AP) mediated the ubiquitination of Rap1GAP by binding to it in HeLa and SiHa cells, but not in C33A cells. However, the levels of Rap1GAP were decreased in HeLa and SiHa cells after knocking down E6AP by siRNA. Silencing of E6AP did not affect the levels of Rap1GAP in C33A cells. Autophagy marker p62 was decreased and LC3 II/LC3 I was increased after knocking down E6AP in HeLa cells, but not in C33A cells. The levels of Rap1GAP were decreased after treating the cells with rapamycin to induce cell autophagy in HeLa and C33A cells. Conclusion Rap1GAP may be degraded by autophagy in cervical cancer cells, but HPV infection can switch the degradation pathway from autophagy to E6AP-mediated ubiquitin-proteasome degradation. E6AP may be a key component of the switch.

scholarly journals E6-mediated activation of JNK drives EGFR signalling to promote proliferation and viral oncoprotein expression in cervical cancer

2020 ◽  
Author(s):  
Ethan L. Morgan ◽  
James A. Scarth ◽  
Molly R. Patterson ◽  
Christopher W. Wasson ◽  
Georgia C. Hemingway ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Human Papillomaviruses ◽  
Signalling Pathway ◽  
Viral Oncoprotein ◽  
Hpv E6 ◽  
Cervical Cancer Cells ◽  
E6 And E7 ◽  
Novel Therapeutic

AbstractHuman papillomaviruses (HPV) are a major cause of malignancy worldwide, contributing to ~5% of all human cancers including almost all cases of cervical cancer and a growing number of ano-genital and oral cancers. HPV-induced malignancy is primarily driven by the viral oncogenes, E6 and E7, which manipulate host cellular pathways to increase cell proliferation and enhance cell survival, ultimately predisposing infected cells to malignant transformation. Consequently, a more detailed understanding of viral-host interactions in HPV-associated disease offers the potential to identify novel therapeutic targets. Here, we identify that the c-Jun N-terminal kinase (JNK) signalling pathway is activated in cervical disease and in cervical cancer. The HPV E6 oncogene induces JNK1/2 phosphorylation in a manner that requires the E6 PDZ binding motif. We show that blockade of JNK1/2 signalling using small molecule inhibitors, or knockdown of the canonical JNK substrate c-Jun, reduces cell proliferation and induces apoptosis in cervical cancer cells. We further demonstrate that this phenotype is at least partially driven by JNK-dependent activation of EGFR signalling via increased expression of EGFR and the EGFR ligands EGF and HB-EGF. JNK/c-Jun signalling promoted the invasive potential of cervical cancer cells and was required for the expression of the epithelial to mesenchymal transition (EMT)-associated transcription factor Slug and the mesenchymal marker Vimentin. Furthermore, JNK/c-Jun signalling is required for the constitutive expression of HPV E6 and E7, which are essential for cervical cancer cell growth and survival. Together, these data demonstrate a positive feedback loop between the EGFR signalling pathway and HPV E6/E7 expression, identifying a regulatory mechanism in which HPV drives EGFR signalling to promote proliferation, survival and EMT. Thus, our study has identified a novel therapeutic target that may be beneficial for the treatment of cervical cancer.

Sign in / Sign up

Export Citation Format

Share Document