RESUMO
Human papillomaviruses (HPVs) infect the oral and anogenital mucosa and can cause cancer. The high-risk (HR)-HPV oncoproteins, E6 and E7, hijack cellular factors to promote cell proliferation, delay differentiation and induce genomic instability, thus predisposing infected cells to malignant transformation. cAMP response element (CRE)-binding protein 1 (CREB1) is a master transcription factor that can function as a proto-oncogene, the abnormal activity of which is associated with multiple cancers. However, little is known about the interplay between HPV and CREB1 activity in cervical cancer or the productive HPV lifecycle. We show that CREB is activated in productively infected primary keratinocytes and that CREB1 expression and phosphorylation is associated with the progression of HPV+ cervical disease. The depletion of CREB1 or inhibition of CREB1 activity results in decreased cell proliferation and reduced expression of markers of epithelial to mesenchymal transition, coupled with reduced migration in HPV+ cervical cancer cell lines. CREB1 expression is negatively regulated by the tumor suppressor microRNA, miR-203a, and CREB1 phosphorylation is controlled through the MAPK/MSK pathway. Crucially, CREB1 directly binds the viral promoter to upregulate transcription of the E6/E7 oncogenes, establishing a positive feedback loop between the HPV oncoproteins and CREB1. Our findings demonstrate the oncogenic function of CREB1 in HPV+ cervical cancer and its relationship with the HPV oncogenes.
Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Papillomavirus Humano , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Transição Epitelial-Mesenquimal , Proteínas Repressoras/genética , Oncogenes , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genéticaRESUMO
Human papillomaviruses (HPV) are a major cause of malignancy worldwide. They are the aetiological agents of almost all cervical cancers as well as a sub-set of other anogenital and head and neck cancers. Hijacking of host cellular pathways is essential for virus pathogenesis; however, a major challenge remains to identify key host targets and to define their contribution to HPV-driven malignancy. The Hippo pathway regulates epithelial homeostasis by down-regulating the function of the transcription factor YAP. Increased YAP expression has been observed in cervical cancer but the mechanisms driving this increase remain unclear. We found significant down-regulation of the master Hippo regulatory kinase STK4 (also termed MST1) in cervical disease samples and cervical cancer cell lines compared with healthy controls. Re-introduction of STK4 inhibited the proliferation of HPV positive cervical cells and this corresponded with decreased YAP nuclear localization and decreased YAP-dependent gene expression. The HPV E6 and E7 oncoproteins maintained low STK4 expression in cervical cancer cells by upregulating the oncomiR miR-18a, which directly targeted the STK4 mRNA 3'UTR. Interestingly, miR-18a knockdown increased STK4 expression and activated the Hippo pathway, significantly reducing cervical cancer cell proliferation. Our results identify STK4 as a key cervical cancer tumour suppressor, which is targeted via miR-18a in HPV positive tumours. Our study indicates that activation of the Hippo pathway may offer a therapeutically beneficial option for cervical cancer treatment.
Assuntos
Transformação Celular Viral , MicroRNAs/metabolismo , Papillomaviridae/metabolismo , Infecções por Papillomavirus/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , RNA Neoplásico/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo , Neoplasias do Colo do Útero/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , MicroRNAs/genética , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Proteínas Serina-Treonina Quinases/genética , RNA Neoplásico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Proteínas de Sinalização YAPRESUMO
Persistent infection with high-risk human papillomaviruses (HR-HPVs) is the causal factor in over 99â% of cervical cancer cases, and a significant proportion of oropharyngeal and anogenital cancers. The key drivers of HPV-mediated transformation are the oncoproteins E5, E6 and E7. Together, they act to prolong cell-cycle progression, delay differentiation and inhibit apoptosis in the host keratinocyte cell in order to generate an environment permissive for viral replication. The oncoproteins also have key roles in mediating evasion of the host immune response, enabling infection to persist. Moreover, prolonged infection within the cellular environment established by the HR-HPV oncoproteins can lead to the acquisition of host genetic mutations, eventually culminating in transformation to malignancy. In this review, we outline the many ways in which the HR-HPV oncoproteins manipulate the host cellular environment, focusing on how these activities can contribute to carcinogenesis.
Assuntos
Alphapapillomavirus/fisiologia , Transformação Celular Viral , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/virologia , Alphapapillomavirus/genética , Alphapapillomavirus/patogenicidade , Apoptose , Carcinogênese , Pontos de Checagem do Ciclo Celular , Diferenciação Celular , Proliferação de Células , Reprogramação Celular , Epigênese Genética , Genoma Viral , Humanos , Evasão da Resposta Imune , Proteínas Oncogênicas Virais/genética , Domínios PDZ , RNA não Traduzido/genética , Transdução de Sinais , Replicação ViralRESUMO
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 are not fully 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 activation of the transcription factor NFκB, involving the small GTPase Rac1, 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 and that activation of this pathway is essential for cervical cancer cell proliferation and survival. 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.
Assuntos
Comunicação Autócrina , Carcinoma de Células Escamosas/metabolismo , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Interleucina-6/metabolismo , NF-kappa B/metabolismo , Proteínas de Neoplasias/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Neoplasias do Colo do Útero/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/virologia , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologiaRESUMO
Human papillomaviruses (HPV) activate a number of host factors to control their differentiation-dependent life cycles. The transcription factor signal transducer and activator of transcription (STAT)-3 is important for cell cycle progression and cell survival in response to cytokines and growth factors. STAT3 requires phosphorylation on Ser727, in addition to phosphorylation on Tyr705 to be transcriptionally active. In this study, we show that STAT3 is essential for the HPV life cycle in undifferentiated and differentiated keratinocytes. Primary human keratinocytes containing high-risk HPV18 genomes display enhanced STAT3 phosphorylation compared to normal keratinocytes. Expression of the E6 oncoprotein is sufficient to induce the dual phosphorylation of STAT3 at Ser727 and Tyr705 by a mechanism requiring Janus kinases and members of the MAPK family. E6-mediated activation of STAT3 induces the transcription of STAT3 responsive genes including cyclin D1 and Bcl-xL. Silencing of STAT3 protein expression by siRNA or inhibition of STAT3 activation by small molecule inhibitors, or by expression of dominant negative STAT3 phosphorylation site mutants, results in blockade of cell cycle progression. Loss of active STAT3 impairs HPV gene expression and prevents episome maintenance in undifferentiated keratinocytes and upon differentiation, lack of active STAT3 abolishes virus genome amplification and late gene expression. Organotypic raft cultures of HPV18 containing keratinocytes expressing a phosphorylation site STAT3 mutant display a profound reduction in suprabasal hyperplasia, which correlates with a loss of cyclin B1 expression and increased differentiation. Finally, increased STAT3 expression and phosphorylation is observed in HPV positive cervical disease biopsies compared to control samples, highlighting a role for STAT3 activation in cervical carcinogenesis. In summary, our data provides evidence of a critical role for STAT3 in the HPV18 life cycle.
Assuntos
Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Papillomavirus Humano 18/fisiologia , Queratinócitos/virologia , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/virologia , Fator de Transcrição STAT3/metabolismo , Replicação Viral/fisiologia , Estudos de Casos e Controles , Células Cultivadas , Feminino , Genoma Viral , Interações Hospedeiro-Patógeno , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Fosforilação , Lesões Intraepiteliais Escamosas Cervicais/metabolismo , Lesões Intraepiteliais Escamosas Cervicais/patologia , Lesões Intraepiteliais Escamosas Cervicais/virologia , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologiaRESUMO
BK polyomavirus (BKPyV; hereafter referred to as BK) causes a lifelong chronic infection and is associated with debilitating disease in kidney transplant recipients. Despite its importance, aspects of the virus life cycle remain poorly understood. In addition to the structural proteins, the late region of the BK genome encodes for an auxiliary protein called agnoprotein. Studies on other polyomavirus agnoproteins have suggested that the protein may contribute to virion infectivity. Here, we demonstrate an essential role for agnoprotein in BK virus release. Viruses lacking agnoprotein fail to release from host cells and do not propagate to wild-type levels. Despite this, agnoprotein is not essential for virion infectivity or morphogenesis. Instead, agnoprotein expression correlates with nuclear egress of BK virions. We demonstrate that the agnoprotein binding partner α-soluble N-ethylmaleimide sensitive fusion (NSF) attachment protein (α-SNAP) is necessary for BK virion release, and siRNA knockdown of α-SNAP prevents nuclear release of wild-type BK virions. These data highlight a novel role for agnoprotein and begin to reveal the mechanism by which polyomaviruses leave an infected cell.
Assuntos
Vírus BK/fisiologia , Infecções por Polyomavirus/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Animais , Vírus BK/genética , Vírus BK/ultraestrutura , Núcleo Celular/metabolismo , Chlorocebus aethiops , Regulação Viral da Expressão Gênica , Membrana Nuclear/metabolismo , Ligação Proteica , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/metabolismo , Transcrição Gênica , Células Vero , Vírion/metabolismo , Vírion/ultraestruturaRESUMO
Ethan L. Morgan works on human papillomaviruses (HPVs), with a specific interest in identifying how HPV induces tumor formation. In this mSphere of Influence article, he reflects on how three papers influenced him. "Comprehensive genomic characterization of head and neck squamous cell carcinomas" (The Cancer Genome Atlas Network, Nature 517:576-582, 2015, https://doi.org/10.1038/nature14129) and "Integrated genomic and molecular characterization of cervical cancer" (The Cancer Genome Atlas Network, Nature 543: 378-384, 2017, https://doi.org/10.1038/nature21386) showed him the power behind comprehensive multi-omic analyses to understand disease biology, while "Human papillomavirus E7 oncoprotein targets RNF168 to hijack the host DNA damage response" (J. Sitz et al., Proc Natl Acad Sci U S A 116:19552-19562, 2019, https://doi.org/10.1073/pnas.1906102116) reinforced how this can be used to undercover potential new drug targets in HPV-associated disease.
Assuntos
Genômica , Humanos , Infecções por Papillomavirus/virologia , Papillomaviridae/genética , Papillomaviridae/patogenicidade , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/genética , Feminino , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , MultiômicaRESUMO
Human papillomaviruses (HPVs) cause most cervical cancers and an increasing number of anogenital and oral carcinomas, with most cases caused by HPV16 or HPV18. HPV hijacks host signalling pathways to promote carcinogenesis. Understanding these interactions could permit identification of much-needed therapeutics for HPV-driven malignancies. The Hippo signalling pathway is important in HPV+ cancers, with the downstream effector YAP playing a pro-oncogenic role. In contrast, the significance of its paralogue TAZ remains largely uncharacterised in these cancers. We demonstrate that TAZ is dysregulated in a HPV-type dependent manner by a distinct mechanism to that of YAP and controls proliferation via alternative cellular targets. Analysis of cervical cancer cell lines and patient biopsies revealed that TAZ expression was only significantly increased in HPV18+ and HPV18-like cells and TAZ knockdown reduced proliferation, migration and invasion only in HPV18+ cells. RNA-sequencing of HPV18+ cervical cells revealed that YAP and TAZ have distinct targets, suggesting they promote carcinogenesis by different mechanisms. Thus, in HPV18+ cancers, YAP and TAZ play non-redundant roles. This analysis identified TOGARAM2 as a previously uncharacterised TAZ target and demonstrates its role as a key effector of TAZ-mediated proliferation, migration and invasion in HPV18+ cancers.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proliferação de Células , Via de Sinalização Hippo , Papillomavirus Humano 18 , Infecções por Papillomavirus , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Fatores de Transcrição , Neoplasias do Colo do Útero , Proteínas de Sinalização YAP , Feminino , Humanos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/metabolismo , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Transativadores/metabolismo , Transativadores/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/metabolismo , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Proteínas de Sinalização YAP/metabolismoRESUMO
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 anogenital 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 the oncogenic phenotype in vitro, whilst having minimal effects in HPV negative cervical cancer cells. Furthermore, we demonstrate that the LASP1 SH3 domain is essential for LASP1-mediated oncogenicity 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 regulates LASP1 mRNA levels by binding to its 3'UTR. Finally, we demonstrate 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 in cervical cancer, thus identifying a potential therapeutic target in these cancers.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proliferação de Células , Proteínas do Citoesqueleto , Proteínas com Domínio LIM , MicroRNAs , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , MicroRNAs/genética , Humanos , Feminino , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proliferação de Células/genética , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Animais , Camundongos , Regulação Neoplásica da Expressão Gênica , Linhagem Celular TumoralRESUMO
Human papillomaviruses (HPV) are a major cause of malignancy, contributing to â¼5% 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 3'UTR. 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.
RESUMO
Head and neck squamous cell carcinoma (HNSCC) remains a prevalent diagnosis with current treatment options that include radiotherapy and immune-mediated therapies, in which tumor necrosis factor-α (TNFα) is a key mediator of cytotoxicity. However, HNSCC and other cancers often display TNFα resistance due to activation of the canonical IKK-NFκB/RELA pathway, which is activated by, and induces expression of, cellular inhibitors of apoptosis proteins (cIAPs). Our previous studies have demonstrated that the IAP inhibitor birinapant sensitized HNSCC to TNFα-dependent cell death in vitro and radiotherapy in vivo. Furthermore, we recently demonstrated that the inhibition of the G2/M checkpoint kinase WEE1 also sensitized HNSCC cells to TNFα-dependent cell death, due to the inhibition of the pro-survival IKK-NFκB/RELA complex. Given these observations, we hypothesized that dual-antagonist therapy targeting both IAP and WEE1 proteins may have the potential to synergistically sensitize HNSCC to TNFα-dependent cell death. Using the IAP inhibitor birinapant and the WEE1 inhibitor AZD1775, we show that combination treatment reduced cell viability, proliferation and survival when compared with individual treatment. Furthermore, combination treatment enhanced the sensitivity of HNSCC cells to TNFα-induced cytotoxicity via the induction of apoptosis and DNA damage. Additionally, birinapant and AZD1775 combination treatment decreased cell proliferation and survival in combination with radiotherapy, a critical source of TNFα. These results support further investigation of IAP and WEE1 inhibitor combinations in preclinical and clinical studies in HNSCC.
RESUMO
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.
Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Fator de Transcrição AP-1 , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Proteínas Oncogênicas Virais/fisiologia , Proteínas E7 de Papillomavirus/genética , Proliferação de Células , Carcinogênese , Trifosfato de AdenosinaRESUMO
TNFα is a key mediator of immune, chemotherapy and radiotherapy-induced cytotoxicity, but several cancers, including head and neck squamous cell carcinomas (HNSCC), display resistance to TNFα due to activation of the canonical NFκB pro-survival pathway. However, direct targeting of this pathway is associated with significant toxicity; thus, it is vital to identify novel mechanism(s) contributing to NFκB activation and TNFα resistance in cancer cells. Here, we demonstrate that the expression of proteasome-associated deubiquitinase USP14 is significantly increased in HNSCC and correlates with worse progression free survival in Human Papillomavirus (HPV)- HNSCC. Inhibition or depletion of USP14 inhibited the proliferation and survival of HNSCC cells. Further, USP14 inhibition reduced both basal and TNFα-inducible NFκB activity, NFκB-dependent gene expression and the nuclear translocation of the NFκB subunit RELA. Mechanistically, USP14 bound to both RELA and IκBα and reduced IκBα K48-ubiquitination leading to the degradation of IκBα, a critical inhibitor of the canonical NFκB pathway. Furthermore, we demonstrated that b-AP15, an inhibitor of USP14 and UCHL5, sensitized HNSCC cells to TNFα-mediated cell death, as well as radiation-induced cell death in vitro. Finally, b-AP15 delayed tumor growth and enhanced survival, both as a monotherapy and in combination with radiation, in HNSCC tumor xenograft models in vivo, which could be significantly attenuated by TNFα depletion. These data offer new insights into the activation of NFκB signaling in HNSCC and demonstrate that small molecule inhibitors targeting the ubiquitin pathway warrant further investigation as a novel therapeutic avenue to sensitize these cancers to TNFα- and radiation-induced cytotoxicity.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Inibidor de NF-kappaB alfa/genética , Fator de Necrose Tumoral alfa/farmacologia , Fator de Necrose Tumoral alfa/genética , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , NF-kappa B , Morte Celular , Linhagem Celular Tumoral , Ubiquitina Tiolesterase/genéticaRESUMO
TNFα is a key mediator of immune and radiotherapy-induced cytotoxicity, but many cancers, including head and neck squamous cell carcinomas (HNSCC), display TNF resistance due to activation of the canonical IKK-NF-κB/RELA pro-survival pathway. However, toxicities associated with direct targeting of the canonical pathway point to the need to identify mechanism(s) contributing to TNFα resistance and synthetic lethal targets to overcome such resistance in cancer cells. Here, RNAi screening for modulators of TNFα-NF-κB reporter activity and cell survival unexpectedly implicated the WEE1 and CDC2 G2-M checkpoint kinases. The IKKα/ß-RELA and WEE1-CDC2 signaling pathways are activated by TNFα and form a complex in cell lines derived from both human papillomavirus (-) and (+) subtypes of HNSCC. WEE1 inhibitor AZD1775 reduced IKK/RELA phosphorylation and the expression of NF-κB-dependent pro-survival proteins Cyclin D1 and BCL2. Combination of TNFα and AZD1775 enhanced caspase-mediated apoptosis in vitro, and combination treatment with radiotherapy and AZD1775 potentiated inhibition of HNSCC tumor xenograft growth in vivo, which could be significantly attenuated by TNFα depletion. These data offer new insight into the interplay between NF-κB signaling and WEE1-mediated regulation of the G2-M cell-cycle checkpoint in HNSCC. IMPLICATIONS: Inhibiting WEE1 and IKK-RELA crosstalk could potentially enhance the effects of therapies mediated by TNFα with less systemic immune suppression and toxicity than observed with direct interruption of IKK-NF-κB/RELA signaling.
Assuntos
Proteínas de Ciclo Celular , Neoplasias de Cabeça e Pescoço , Quinase I-kappa B , Proteínas Tirosina Quinases , Fator de Transcrição RelA , Apoptose , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , NF-kappa B/metabolismo , Proteínas Tirosina Quinases/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Fator de Transcrição RelA/genética , Fator de Necrose Tumoral alfaRESUMO
Protein 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 ~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. Furthermore, reduced Mcl-1 expression partially contributed to the observed proliferative defect in USP13 depleted cells. 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.
Assuntos
Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Estabilidade Proteica/efeitos dos fármacos , Proteases Específicas de Ubiquitina/genética , Neoplasias do Colo do Útero/genética , Compostos de Anilina/farmacologia , Proliferação de Células/efeitos dos fármacos , Enzimas Desubiquitinantes/genética , Feminino , Homeostase/genética , Humanos , Oncogenes , Sulfonamidas/farmacologia , Ubiquitina/genética , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologiaRESUMO
Human 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.
Assuntos
MAP Quinase Quinase 4/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Neoplasias do Colo do Útero/genética , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Transdução de Sinais , Microambiente Tumoral , Neoplasias do Colo do Útero/patologiaRESUMO
Human papillomaviruses (HPVs) are small, DNA viruses that cause around 5% of all cancers in humans, including almost all cervical cancer cases and a significant proportion of anogenital and oral cancers. The HPV oncoproteins E5, E6 and E7 manipulate cellular signalling pathways to evade the immune response and promote virus persistence. The Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway has emerged as a key mediator in a wide range of important biological signalling pathways, including cell proliferation, cell survival and the immune response. While STAT1 and STAT2 primarily drive immune signalling initiated by interferons, STAT3 and STAT5 have widely been linked to the survival and proliferative potential of a number of cancers. As such, the inhibition of STAT3 and STAT5 may offer a therapeutic benefit in HPV-associated cancers. In this review, we will discuss how HPV manipulates JAK/STAT signalling to evade the immune system and promote cell proliferation, enabling viral persistence and driving cancer development. We also discuss approaches to inhibit the JAK/STAT pathway and how these could potentially be used in the treatment of HPV-associated disease.
Assuntos
Alphapapillomavirus/patogenicidade , Janus Quinases/metabolismo , Neoplasias/virologia , Infecções por Papillomavirus/virologia , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Alphapapillomavirus/fisiologia , Antineoplásicos/uso terapêutico , Antivirais/uso terapêutico , Carcinogênese , Feminino , Humanos , Evasão da Resposta Imune , Interferons/metabolismo , Janus Quinases/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/imunologia , Fatores de Transcrição STAT/antagonistas & inibidores , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with over 600,000 cases per year. The primary causes for HNSCC include smoking and alcohol consumption, with an increasing number of cases attributed to infection with Human Papillomavirus (HPV). The treatment options for HNSCC currently include surgery, radiotherapy, and/or platinum-based chemotherapeutics. Cetuximab (targeting EGFR) and Pembrolizumab (targeting PD-1) have been approved for advanced stage, recurrent, and/or metastatic HNSCC. Despite these advances, whilst HPV+ HNSCC has a 3-year overall survival (OS) rate of around 80%, the 3-year OS for HPV- HNSCC is still around 55%. Aberrant signal activation of transcription factor NFκB plays an important role in the pathogenesis and therapeutic resistance of HNSCC. As an important mediator of inflammatory signalling and the immune response to pathogens, the NFκB pathway is tightly regulated to prevent chronic inflammation, a key driver of tumorigenesis. Here, we discuss how NFκB signalling is regulated by the ubiquitin pathway and how this pathway is deregulated in HNSCC. Finally, we discuss the current strategies available to target the ubiquitin pathway and how this may offer a potential therapeutic benefit in HNSCC.
RESUMO
BK polyomavirus (BKPyV) is a ubiquitous pathogen in the human population that is asymptomatic in healthy individuals, but can be life-threatening in those undergoing kidney transplant. To-date, no vaccines or anti-viral therapies are available to treat human BKPyV infections. New therapeutic strategies are urgently required. In this study, using a rational pharmacological screening regimen of known ion channel modulating compounds, we show that BKPyV requires cystic fibrosis transmembrane conductance regulator (CFTR) activity to infect primary renal proximal tubular epithelial cells. Disrupting CFTR function through treatment with the clinically available drug glibenclamide, the CFTR inhibitor CFTR172, or CFTR-silencing, all reduced BKPyV infection. Specifically, time of addition assays and the assessment of the exposure of VP2/VP3 minor capsid proteins indicated a role for CFTR during BKPyV transport to the endoplasmic reticulum, an essential step during the early stages of BKPyV infection. We thus establish CFTR as an important host-factor in the BKPyV life cycle and reveal CFTR modulators as potential anti-BKPyV therapies.
Assuntos
Antivirais/farmacologia , Vírus BK/efeitos dos fármacos , Regulador de Condutância Transmembrana em Fibrose Cística/antagonistas & inibidores , Glibureto/farmacologia , Vírus BK/fisiologia , Proteínas do Capsídeo/metabolismo , Células Cultivadas , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Humanos , Canais KATP/antagonistas & inibidores , Canais KATP/metabolismo , Túbulos Renais Proximais , Bloqueadores dos Canais de Potássio/farmacologia , Urotélio/citologia , Urotélio/virologia , Replicação ViralRESUMO
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 compared to 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.IMPORTANCE HPV16 is the major human viral carcinogen, responsible for around 3 to 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 or 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 since 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.