RESUMO
Non-coding RNA (ncRNA) regulatory networks are emerging as critical regulators of gene expression. These intricate networks of ncRNA:ncRNA interactions modulate multiple cellular pathways and impact the development and progression of multiple diseases. Herpesviruses, including Kaposi's sarcoma-associated herpesvirus, are adept at utilising ncRNAs, encoding their own as well as dysregulating host ncRNAs to modulate virus gene expression and the host response to infection. Research has mainly focused on unidirectional ncRNA-mediated regulation of target protein-coding transcripts; however, we identify a novel host ncRNA regulatory network essential for KSHV lytic replication in B cells. KSHV-mediated upregulation of the host cell circRNA, circHIPK3, is a key component of this network, functioning as a competing endogenous RNA of miR-30c, leading to increased levels of the miR-30c target, DLL4. Dysregulation of this network highlights a novel mechanism of cell cycle control during KSHV lytic replication in B cells. Importantly, disruption at any point within this novel ncRNA regulatory network has a detrimental effect on KSHV lytic replication, highlighting the essential nature of this network and potential for therapeutic intervention.
Assuntos
Herpesvirus Humano 8 , MicroRNAs , Linfócitos B , Herpesvirus Humano 8/genética , MicroRNAs/genética , RNA Circular/genética , Regulação para CimaRESUMO
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
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
The epitranscriptomic modification N6-methyladenosine (m6A) is a ubiquitous feature of the mammalian transcriptome. It modulates mRNA fate and dynamics to exert regulatory control over numerous cellular processes and disease pathways, including viral infection. Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation from the latent phase leads to the redistribution of m6A topology upon both viral and cellular mRNAs within infected cells. Here we investigate the role of m6A in cellular transcripts upregulated during KSHV lytic replication. Our results show that m6A is crucial for the stability of the GPRC5A mRNA, whose expression is induced by the KSHV latent-lytic switch master regulator, the replication and transcription activator (RTA) protein. Moreover, we demonstrate that GPRC5A is essential for efficient KSHV lytic replication by directly regulating NFκB signalling. Overall, this work highlights the central importance of m6A in modulating cellular gene expression to influence viral infection.
Assuntos
Herpesvirus Humano 8 , Herpesvirus Humano 8/genética , Latência Viral/genética , Linhagem Celular Tumoral , Transdução de Sinais , RNA Mensageiro/genética , Replicação Viral , Regulação Viral da Expressão GênicaRESUMO
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
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.