Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 453
Filtrar
1.
PLoS One ; 15(12): e0242465, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332365

RESUMO

Peroxiredoxin 2 (PRDX2) is upregulated in various cancers including oral squamous cell carcinoma (OSCC). It is a known tumor promoter in some cancers, but its role in OSCC is unclear. This study aimed to investigate the effect of arecoline, an alkaloid of the betel nut, and human papillomavirus type 16 (HPV16) E6/E7 oncoproteins on induction of PRDX2 expression, and also the effects of PRDX2 overexpression in oral cell lines. Levels of PRDX2 protein were determined using western blot analysis of samples of exfoliated normal oral cells (n = 75) and oral lesion cells from OSCC cases (n = 75). Some OSCC cases were positive for HPV infection and some patients had a history of betel quid chewing. To explore the level of PRDX2 by western blot, the proteins were extracted from oral cell lines that were treated with arecoline or retroviruses containing HPV16 E6 gene and HPV16 E6/E7 expressing vector. For analysis of PRDX2 functions, cell proliferation, cell-cycle progression, apoptosis and migration was compared between oral cells overexpressing PRDX2 and cells with PRDX2-knockdown. PRDX2 expression levels tended to be higher in OSCC samples that were positive for HPV infection and had history of betel quid chewing. Arecoline treatment in vitro at low concentrations and overexpression of HPV16 E6 or E6/E7 in oral cells induced PRDX2 overexpression. Interestingly, in oral cells, PRDX2 promoted cell proliferation, cell-cycle progression (G2/M phase), cell migration and inhibited apoptosis. Upregulation of PRDX2 in oral cells was induced by arecoline and HPV16 oncoproteins and promoted growth of OSCC cells.


Assuntos
Arecolina/farmacologia , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Bucais/genética , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Peroxirredoxinas/genética , Proteínas Repressoras/genética , Idoso , Apoptose/genética , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Papillomavirus Humano 16/química , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/enzimologia , Neoplasias Bucais/patologia , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Peroxirredoxinas/antagonistas & inibidores , Peroxirredoxinas/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais , Transfecção
2.
Int J Mol Sci ; 21(24)2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33333786

RESUMO

Although the effect of hypoxia on p53 in human papillomavirus (HPV)-positive cancer cells has been studied for decades, the impact of p53 regulation on downstream targets and cellular adaptation processes during different periods under hypoxia remains elusive. Here, we show that, despite continuous repression of HPV16 E6/E7 oncogenes, p53 did not instantly recover but instead showed a biphasic regulation marked by further depletion within 24 h followed by an increase at 72 h. Of note, during E6/E7 oncogene suppression, lysosomal degradation antagonizes p53 reconstitution. Consequently, the transcription of p53 responsive genes associated with senescence (e.g., PML and YPEL3) cannot be upregulated. In contrast, downstream genes involved in autophagy (e.g., DRAM1 and BNIP3) were activated, allowing the evasion of senescence under hypoxic conditions. Hence, dynamic regulation of p53 along with its downstream network of responsive genes favors cellular adaptation and enhances cell survival, although the expression of the viral E6/E7-oncogenes as drivers for proliferation remained inhibited under hypoxia.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Papillomavirus Humano 16/metabolismo , Infecções por Papillomavirus/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Colo do Útero/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/genética , Hipóxia Celular/genética , Senescência Celular/genética , Regulação para Baixo , Feminino , Papillomavirus Humano 16/genética , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/genética , Proteína da Leucemia Promielocítica/genética , Proteína da Leucemia Promielocítica/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA Interferente Pequeno , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/virologia
3.
PLoS One ; 15(6): e0235065, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584870

RESUMO

INTRODUCTION: Human papillomavirus (HPV) infection is associated with the development of anogenital and head and neck cancers. In recent years a potential role of HPV in colorectal cancer (CRC) has been suggested. OBJECTIVE: To investigate the presence of HPV in colorectal carcinomas and to study the role of p16INK4a as a marker of transcriptionally active HPV infection. In addition, to investigate the correlation between these findings and the CRC prognostic factors. METHODS: Case control study with 92 cases of colorectal cancers, 75 controls of normal tissue adjacent to the tumor, and 30 controls of precursor lesions, including polyps and colorectal adenomas. Paraffinized samples were used, HPV detection and genotyping were performed by PCR and reverse hybridization by using the INNO LIPA kit, with SPF10 plus primers. The expression of the p16INK4a protein was investigated using immunohistochemistry. Data analysis was performed using descriptive, univariate statistics and survival curves were calculated by using the Kaplan Meier and log-rank method. RESULTS: HPV was detected in 13% of the cases and the most prevalent genotype was HPV 16. HPV DNA was not detected in either control groups. The high expression of p16INK4a was observed in 30% of the cases, but it was not associated to the presence of HPV. The overall survival was 53.3% and was influenced by prognostic factors such as later stage, lymph node and distant metastasis. CONCLUSIONS: Based on these results, HPV is unlikely to be involved in colorectal carcinogenesis and p16INK4a expression is not a relevant marker of transcriptionally active HPV infection in CRC.


Assuntos
Neoplasias Colorretais , Inibidor p16 de Quinase Dependente de Ciclina , Regulação Neoplásica da Expressão Gênica , Papillomavirus Humano 16 , Infecções por Papillomavirus , Adulto , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/virologia , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia
4.
Nat Commun ; 11(1): 2019, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32332747

RESUMO

Retinoblastoma protein (Rb) is a tumor suppressor that binds and represses E2F transcription factors. In cervical cancer cells, human papilloma virus (HPV) protein E7 binds to Rb, releasing it from E2F to promote cell cycle progression, and inducing ubiquitination of Rb. E7-mediated proteasomal degradation of Rb requires action by another protease, calpain, which cleaves Rb after Lys 810. However, it is not clear why cleavage is required for Rb degradation. Here, we report that the proteasome cannot initiate degradation efficiently on full-length Rb. Calpain cleavage exposes a region that is recognized by the proteasome, leading to rapid proteolysis of Rb. These findings identify a mechanism for regulating protein stability by controlling initiation and provide a better understanding of the molecular mechanism underlying transformation by HPV.


Assuntos
Calpaína/metabolismo , Fatores de Transcrição E2F/genética , Regulação Neoplásica da Expressão Gênica , Proteínas E7 de Papillomavirus/metabolismo , Proteínas de Ligação a Retinoblastoma/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias do Colo do Útero/genética , Acrilatos/farmacologia , Calpaína/antagonistas & inibidores , Ciclo Celular/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Ciclopentanos/farmacologia , Fatores de Transcrição E2F/metabolismo , Feminino , Células HEK293 , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Humanos , Proteína NEDD8/antagonistas & inibidores , Proteína NEDD8/metabolismo , Oligopeptídeos/farmacologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica/efeitos dos fármacos , Pirimidinas/farmacologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
5.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188731

RESUMO

Human papillomavirus 16 (HPV16), the leading cause of cervical cancer, exploits a novel endocytic pathway during host cell entry. This mechanism shares many requirements with macropinocytosis but differs in the mode of vesicle formation. Previous work indicated a role of the epidermal growth factor receptor (EGFR) in HPV16 endocytosis. However, the functional outcome of EGFR signaling and its downstream targets during HPV16 uptake are not well characterized. Here, we analyzed the functional importance of signal transduction via EGFR and its downstream effectors for endocytosis of HPV16. Our findings indicate two phases of EGFR signaling as follows: a-likely dispensable-transient activation with or shortly after cell binding and signaling required throughout the process of asynchronous internalization of HPV16. Interestingly, EGFR inhibition interfered with virus internalization and strongly reduced the number of endocytic pits, suggesting a role for EGFR signaling in the induction of HPV16 endocytosis. Moreover, we identified the Src-related kinase Abl2 as a novel regulator of virus uptake. Inhibition of Abl2 resulted in an accumulation of misshaped endocytic pits, indicating Abl2's importance for endocytic vesicle maturation. Since Abl2 rather than Src, a regulator of membrane ruffling during macropinocytosis, mediated downstream signaling of EGFR, we propose that the selective effector targeting downstream of EGFR determines whether HPV16 endocytosis or macropinocytosis is induced.IMPORTANCE Human papillomaviruses are small, nonenveloped DNA viruses that infect skin and mucosa. The so-called high-risk HPVs (e.g., HPV16, HPV18, HPV31) have transforming potential and are associated with various anogenital and oropharyngeal tumors. These viruses enter host cells by a novel endocytic pathway with unknown cellular function. To date, it is unclear how endocytic vesicle formation occurs mechanistically. Here, we addressed the role of epidermal growth factor receptor signaling, which has previously been implicated in HPV16 endocytosis and identified the kinase Abl2 as a novel regulator of virus uptake. Since other viruses, such as influenza A virus and lymphocytic choriomeningitis virus, possibly make use of related mechanisms, our findings shed light on fundamental strategies of virus entry and may in turn help to develop new host cell-targeted antiviral strategies.


Assuntos
Endocitose , Papillomavirus Humano 16/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais , Internalização do Vírus , Animais , Receptores ErbB/genética , Receptores ErbB/metabolismo , Células HeLa , Papillomavirus Humano 16/genética , Humanos , Camundongos , Proteínas Tirosina Quinases/genética
6.
Anticancer Res ; 40(2): 825-835, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32014925

RESUMO

BACKGROUND: Despite extensive research into new treatment options, the prognosis for head and neck squamous cell carcinoma remains poor. Platelet-derived growth factor (PDGF) is up-regulated in HNSCC and expression levels decrease after surgery, suggesting its role in tumour development. The influence of HPV on the PDGF/PDGF receptor (PDGFR) pathway remains unclear. In this study, we investigated the effect of small-molecule tyrosine kinase inhibitors (TKIs) on the expression of PDGF and its receptor in vitro using squamous cancer cell lines with different human papillomavirus 16 (HPV16) status. MATERIALS AND METHODS: Two human HPV16-negative cell lines (UMSCC-11A/-14C) and one HPV16-positive cell line (CERV196) were used. Tumour cells were incubated with 20 µmol/l of TKIs nilotinib, dasatinib, afatinib, gefitinib and erlotinib for 24-96 h. Cell proliferation was assessed via proliferation assay and protein concentrations of PDGF-AA and BB and PDGFRα and -ß via sandwich enzyme-linked immunosorbent assay. For statistical analysis, the results were compared with those from an untreated negative control. RESULTS: PDGF-AA/BB and PDGFRα/-ß were detected in all three tested cell lines. The addition of TKI led to a significant (p<0.05) decrease of PDGF/PDGFR at different time points and cell lines. The strongest effects were seen for the expression of PDGF-AA, which was consistently inhibited by most drugs. The effects of the TKI were independent of the HPV status. CONCLUSION: Proteins of this pathway can effectively be inhibited by small molecule TKIs. PDGF-AA seems to be a promising target for future studies with selective TKIs.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Papillomavirus Humano 16/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Carcinoma de Células Escamosas/patologia , Humanos
7.
Int J Oral Sci ; 12(1): 3, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911577

RESUMO

High-risk human papillomaviruses (HPVs) are involved in the development of several human cancers, including oropharyngeal squamous cell carcinomas. However, many studies have demonstrated that HPV alone is not sufficient for the oncogenic transformation of normal human epithelial cells, indicating that additional cofactors are required for the oncogenic conversion of HPV-infected cells. Inasmuch as chronic inflammation is also closely associated with carcinogenesis, we investigated the effect of chronic exposure to tumor necrosis factor α (TNFα), the major proinflammatory cytokine, on oncogenesis in two immortalized oral keratinocyte cell lines, namely, HPV16-immortalized and human telomerase reverse transcriptase (hTERT)-immortalized cells. TNFα treatment led to the acquisition of malignant growth properties in HPV16-immortalized cells, such as (1) calcium resistance, (2) anchorage independence, and (3) increased cell proliferation in vivo. Moreover, TNFα increased the cancer stem cell-like population and stemness phenotype in HPV16-immortalized cells. However, such transforming effects were not observed in hTERT-immortalized cells, suggesting an HPV-specific role in TNFα-promoted oncogenesis. We also generated hTERT-immortalized cells that express HPV16 E6 and E7. Chronic TNFα exposure successfully induced the malignant growth and stemness phenotype in the E6-expressing cells but not in the control and E7-expressing cells. We further demonstrated that HPV16 E6 played a key role in TNFα-induced cancer stemness via suppression of the stemness-inhibiting microRNAs miR-203 and miR-200c. Overexpression of miR-203 and miR-200c suppressed cancer stemness in TNFα-treated HPV16-immortalized cells. Overall, our study suggests that chronic inflammation promotes cancer stemness in HPV-infected cells, thereby promoting HPV-associated oral carcinogenesis.


Assuntos
Carcinoma de Células Escamosas/genética , Papillomavirus Humano 16/metabolismo , MicroRNAs/metabolismo , Neoplasias Bucais/genética , Boca/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/virologia , Telomerase/genética , Fator de Necrose Tumoral alfa/metabolismo , Carcinogênese/genética , Carcinogênese/imunologia , Carcinoma de Células Escamosas/patologia , Transformação Celular Viral/genética , Regulação da Expressão Gênica , Genes Virais , Papillomavirus Humano 16/genética , Humanos , MicroRNAs/genética , Boca/virologia , Neoplasias Bucais/patologia , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Telomerase/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
8.
Cancer Res ; 80(4): 732-746, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31848196

RESUMO

There is a critical need to understand mechanisms of resistance and to develop combinatorial strategies to improve responses to checkpoint blockade immunotherapy (CBI). Here, we uncover a novel mechanism by which the human papillomavirus (HPV) inhibits the activity of CBI in head and neck squamous cell carcinoma (HNSCC). Using orthotopic HNSCC models, we show that radiation combined with anti-PD-L1 immunotherapy significantly enhanced local control, CD8+ memory T cells, and induced preferential T-cell homing via modulation of vascular endothelial cells. However, the HPV E5 oncoprotein suppressed immune responses by downregulating expression of major histocompatibility complex and interfering with antigen presentation in murine models and patient tumors. Furthermore, tumors expressing HPV E5 were rendered entirely resistant to anti-PD-L1 immunotherapy, and patients with high expression of HPV16 E5 had worse survival. The antiviral E5 inhibitor rimantadine demonstrated remarkable single-agent antitumor activity. This is the first report that describes HPV E5 as a mediator of resistance to anti-PD-1/PD-L1 immunotherapy and demonstrates the antitumor activity of rimantadine. These results have broad clinical relevance beyond HNSCC to other HPV-associated malignancies and reveal a powerful mechanism of HPV-mediated immunosuppression, which can be exploited to improve response rates to checkpoint blockade. SIGNIFICANCE: This study identifies a novel mechanism of resistance to anti-PD-1/PD-L1 immunotherapy mediated by HPV E5, which can be exploited using the HPV E5 inhibitor rimantadine to improve outcomes for head and neck cancer patients. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/4/732/F1.large.jpg.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias de Cabeça e Pescoço/terapia , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/terapia , Rimantadina/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Adolescente , Adulto , Idoso , Animais , Apresentação do Antígeno/efeitos dos fármacos , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linhagem Celular Tumoral/transplante , Quimiorradioterapia/métodos , Estudos de Coortes , Modelos Animais de Doenças , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/virologia , Voluntários Saudáveis , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/antagonistas & inibidores , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Células RAW 264.7 , RNA-Seq , Rimantadina/uso terapêutico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Adulto Jovem
9.
Mol Med Rep ; 21(1): 209-219, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746391

RESUMO

Previous microRNA (miR) microarray analysis revealed that miR­218 is downregulated in cervical cancer tissues. The present study aimed to further evaluate the expression of miR­218 in cervical cancer specimens, determine the association between its expression with disease progression, and investigate the roles of miR­218 in cervical cancer cells. Tissue specimens were obtained from 80 patients with cervical squamous cell carcinoma, 30 patients with high­grade cervical intraepithelial neoplasia [(CIN) II/III] and 15 patients with low­grade CIN (CINI); in addition, 60 plasma samples were obtained from patients with cervical cancer, and 15 normal cervical tissue specimens and 30 plasma samples were obtained from healthy women. These samples were used for analysis of miR­218 expression via reverse transcription­-quantitative PCR. In addition, tumor cells were transfected with miR­218 mimics, human papillomavirus (HPV)16 E6/E7 small interfering RNA, or their respective negative controls to determine the viability, colony formation, migration and invasion of cells using MTT, colony formation, wound healing and Transwell assays, respectively. Target genes of miR­218 were bioinformatically predicted and analyzed using Gene Ontology (GO) terms. The results revealed that miR­218 was downregulated in the tumor tissues and plasma of patients with cervical cancer, with expression associated with the advanced clinicopathological characteristics of patients, including HPV positivity, tumor size, blood vessel invasion and lymph node metastasis. Furthermore, miR­218 overexpression reduced tumor cell viability and xenograft growth, and suppressed tumor cell migration and invasion. HPV was detected in 75% of the 80 patients with cervical cancer, and HPV positivity was inversely associated with miR­218 expression. In addition, bioinformatics analysis predicted that roundabout guidance receptor 1 (ROBO1) was a target gene of miR­218; miR­218 overexpression significantly reduced ROBO1 levels. Furthermore, GO analysis revealed that ROBO1 was involved in regulating cell proliferation, adhesion and migration, and the cell cycle. In conclusion, the findings of the present study suggested that miR­218 may possess antitumor activities in cervical cancer.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Genes Supressores de Tumor , RNA Neoplásico/metabolismo , Neoplasias do Colo do Útero/metabolismo , Animais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/virologia , Feminino , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Células HeLa , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Oncogênicas Virais/biossíntese , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/biossíntese , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , RNA Neoplásico/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
10.
J Virol ; 94(2)2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31666385

RESUMO

Human papillomaviruses (HPVs) infect keratinocytes of stratified epithelia. Long-term persistence of infection is a critical risk factor for the development of HPV-induced malignancies. Through the actions of its oncogenes, HPV evades host immune responses to facilitate its productive life cycle. In this work, we discovered a previously unknown function of the HPV16 E5 oncoprotein in the suppression of interferon (IFN) responses. This suppression is focused on keratinocyte-specific IFN-κ and is mediated through E5-induced changes in growth factor signaling pathways, as identified through phosphoproteomics analysis. The loss of E5 in keratinocytes maintaining the complete HPV16 genome results in the derepression of IFNK transcription and subsequent JAK/STAT-dependent upregulation of several IFN-stimulated genes (ISGs) at both the mRNA and protein levels. We also established a link between the loss of E5 and the subsequent loss of genome maintenance and stability, resulting in increased genome integration.IMPORTANCE Persistent human papillomavirus infections can cause a variety of significant cancers. The ability of HPV to persist depends on evasion of the host immune system. In this study, we show that the HPV16 E5 protein can suppress an important aspect of the host immune response. In addition, we find that the E5 protein is important for helping the virus avoid integration into the host genome, which is a frequent step along the pathway to cancer development.


Assuntos
Genoma Viral , Papillomavirus Humano 16/metabolismo , Interferon Tipo I/metabolismo , Queratinócitos , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus , Plasmídeos/metabolismo , Transdução de Sinais , Linhagem Celular , Instabilidade Genômica , Papillomavirus Humano 16/genética , Humanos , Interferon Tipo I/genética , Queratinócitos/metabolismo , Queratinócitos/patologia , Queratinócitos/virologia , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Plasmídeos/genética
11.
Cancer Lett ; 470: 115-125, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31693922

RESUMO

Despite prophylactic vaccination campaigns, human papillomavirus (HPV)-induced cancers still represent a major medical issue for global population, thus specific anti-HPV drugs are needed. Since the ability of HPV E6 oncoprotein to promote p53 degradation is linked to tumor progression, E6 has been proposed as an ideal target for cancer treatment. Using the crystal structure of the E6/E6AP/p53 complex, we performed an in silico screening of small-molecule libraries against a highly conserved alpha-helix in the N-terminal domain of E6 involved in the E6-p53 interaction. We discovered a compound able to inhibit the E6-mediated degradation of p53 through disruption of E6-p53 binding both in vitro and in cells. This compound could restore p53 intracellular levels and transcriptional activity, reduce the viability and proliferation of HPV-positive cancer cells, and block 3D cervospheres formation. Mechanistic studies revealed that the compound anti-tumor activity mainly relies on induction of cell cycle arrest and senescence. Our data demonstrate that the disruption of the direct E6-p53 interaction can be obtained with a small-molecule compound leading to specific antitumoral activity in HPV-positive cancer cells and thus represents a new approach for anti-HPV drug development.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Proteínas Oncogênicas Virais/antagonistas & inibidores , Infecções por Papillomavirus/tratamento farmacológico , Proteínas Repressoras/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Simulação por Computador , Cristalografia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Humanos , Simulação de Dinâmica Molecular , Estrutura Molecular , Neoplasias/patologia , Neoplasias/virologia , Proteínas Oncogênicas Virais/química , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Ligação Proteica/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Esferoides Celulares , Relação Estrutura-Atividade
12.
J Virol ; 94(1)2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31597772

RESUMO

Cancer-causing human papillomavirus (HPV) E6 oncoproteins have a class I PDZ-binding motif (PBM) on their C termini, which play critical roles that are related to the HPV life cycle and HPV-induced malignancies. E6 oncoproteins use these PBMs to interact with, to target for proteasome-mediated degradation, a plethora of cellular substrates that contain PDZ domains and that are involved in the regulation of various cellular pathways. In this study, we show that both HPV-16 and HPV-18 E6 oncoproteins can interact with Na+/H+ exchange regulatory factor 2 (NHERF-2), a PDZ domain-containing protein, which among other cellular functions also behaves as a tumor suppressor regulating endothelial proliferation. The interaction between the E6 oncoproteins and NHERF-2 is PBM dependent and results in proteasome-mediated degradation of NHERF-2. We further confirmed this effect in cells derived from HPV-16- and HPV-18-positive cervical tumors, where we show that NHERF-2 protein turnover is increased in the presence of E6. Finally, our data indicate that E6-mediated NHERF-2 degradation results in p27 downregulation and cyclin D1 upregulation, leading to accelerated cellular proliferation. To our knowledge, this is the first report to demonstrate that E6 oncoproteins can stimulate cell proliferation by indirectly regulating p27 through targeting a PDZ domain-containing protein.IMPORTANCE This study links HPV-16 and HPV-18 E6 oncoproteins to the modulation of cellular proliferation. The PDZ domain-containing protein NHERF-2 is a tumor suppressor that has been shown to regulate endothelial proliferation; here, we demonstrate that NHERF-2 is targeted by HPV E6 for proteasome-mediated degradation. Interestingly, this indirectly affects p27, cyclin D1, and CDK4 protein levels and, consequently, affects cell proliferation. Hence, this study provides information that will improve our understanding of the molecular basis for HPV E6 function, and it also highlights the importance of the PDZ domain-containing protein NHERF-2 and its tumor-suppressive role in regulating cell proliferation.


Assuntos
Proteínas de Ligação a DNA/genética , Interações Hospedeiro-Patógeno/genética , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Proteínas Oncogênicas Virais/genética , Fosfoproteínas/genética , Proteínas Repressoras/genética , Trocadores de Sódio-Hidrogênio/genética , Sítios de Ligação , Linhagem Celular Transformada , Proliferação de Células , Ciclina D1/genética , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células Endoteliais/virologia , Feminino , Regulação da Expressão Gênica , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Papillomavirus Humano 18/metabolismo , Papillomavirus Humano 18/patogenicidade , Humanos , Proteínas Oncogênicas Virais/metabolismo , Domínios PDZ , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Fosfoproteínas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Proteínas Repressoras/metabolismo , Transdução de Sinais , Trocadores de Sódio-Hidrogênio/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
13.
Arch Virol ; 164(12): 2953-2961, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31552532

RESUMO

Human papillomavirus genotype 16 (HPV16) is the most frequent high-risk HPV (HR-HPV) identified in cervical precursor lesions and cervical cancer (CC) worldwide. The oncogenic potential of HPV16 is partly dependent on the lineage involved in the infection and the presence of clinically relevant mutations. In this report, we present the distribution of HR-HPV and the mutational profile and intra-host variability of HPV16 lineages, based on analysis of the long control region (LCR) and the E6 gene in samples with normal cytology (n = 39), squamous intraepithelial lesions (n = 25), and CC (n = 39). HR-HPV genotyping was performed using multiplex real-time PCR. HPV16 lineage assignments and mutation frequencies were determined by conventional PCR and Sanger DNA sequencing, and intra-patient viral populations were analyzed using next-generation sequencing (NGS). The most frequent HR-HPV type was HPV16, followed by HPV31 and HPV18. The frequency of HPV16 sublineages was A1/A2 > D2 > D3 and B1. Moreover, the most frequent mutations, both in samples from this study and in the available sequences from Mexican isolates in the GenBank database were LCR-G7518A, which is involved in carcinogenesis, and E6-T350G (producing L83V), associated with persistence of infection. Otherwise, deep sequencing revealed high conservation of viral lineages and mutations, independently of the stages studied. In conclusion, the high frequency and stability of these molecular markers, as well as the circulating viral lineages, could be related to the incidence of CC associated with HPV16. Hence, they deserve a broader analysis to determine the risk of specific populations for progression of the disease.


Assuntos
Papillomavirus Humano 16/genética , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/virologia , Proteínas Repressoras/genética , Sequências Repetidas Terminais , Neoplasias do Colo do Útero/virologia , Adulto , Sequência de Bases , Feminino , Regulação Viral da Expressão Gênica , Papillomavirus Humano 16/classificação , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 16/metabolismo , Humanos , México , Mutação , Proteínas Oncogênicas Virais/metabolismo , Filogenia , Proteínas Repressoras/metabolismo , Estudos Retrospectivos
14.
Oncol Rep ; 42(5): 2139-2148, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31436299

RESUMO

Curcumin is a natural antioxidant polyphenol, which decreases epithelial­mesenchymal transition (EMT) and cell migration in cervical cancer cells. However, the mechanism by which such a decrease occurs is unclear. It is well established that cervical cancer can be caused by high­risk human papillomavirus (HPV), which overexpresses E6 and E7 oncoproteins. Recent findings have suggested that viral oncoproteins regulate the expression of Pirin, which is an oxidative stress sensor involved in EMT and cell migration. Molecular markers associated with EMT, pirin and HPV were evaluated using reverse transcription­reverse quantitative PCR and western blotting. In addition, the migratory ability of cells was evaluated using a Transwell assay. In order to evaluate the role of Pirin in curcumin­mediated inhibition of EMT, SiHa cervical carcinoma cells, which contain two integrated copies of HPV16, were exposed to curcumin. Cell migration, and the expression levels of EMT biomarkers and the pirin protein, which is a product of the PIR gene, were subsequently evaluated. The results demonstrated a significant decrease in EMT following exposure to 20 µM curcumin for 72 h. This finding was supported by a decrease in the protein expression levels of N­cadherin, Vimentin and Slug. Furthermore, it was observed that PIR expression and Pirin protein levels were significantly decreased when SiHa cells were exposed to curcumin. Subsequently, to analyze the effects of Pirin on EMT, SiHa cells were transfected with a small interfering RNA (siRNA) to knockdown PIR. A significant increase in E­cadherin mRNA expression and a decrease in N­cadherin protein expression were observed. In addition, a similar decrease was observed when SiHa cells were exposed to both PIR siRNA and curcumin. Finally, a significant decrease in SiHa cell migration was observed in the presence of 20 µM curcumin compared with in the control group. These findings suggested that curcumin may decrease EMT, at least in part by a Pirin­dependent mechanism. Therefore, Pirin protein may be an important pharmacological target for cervical cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Curcumina/farmacologia , Dioxigenases/genética , Dioxigenases/metabolismo , Neoplasias do Colo do Útero/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo , Ensaios de Seleção de Medicamentos Antitumorais , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/virologia
15.
Cancer Med ; 8(9): 4404-4416, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31215164

RESUMO

BACKGROUNDS: Although the role of high-risk human papillomavirus (HPV) E6 and E7 in cellular malignant transformation has been elucidated, the function of both genes in cellular homeostasis is still unknown. Autophagy functions in maintenance of cellular homeostasis play a key role in the initiation and development of cancer and infectious disease. METHODS: Cervical cancer cell lines SiHa and CaSki were utilized in this study. RESULTS: We found that HPV 16E6/E7 (16E6/E7) downregulation inhibited autophagy, and consequently suppressed cell proliferation and promoted early apoptosis. Transcriptome sequencing demonstrated that Atg9B and LAMP1 were downregulated in 16E6/E7 knockdown cells. Gene function experiments revealed that 16E6/E7 downregulation depressed Atg9B and LAMP1, and Atg9B and LAMP1 overexpression compensated, at least partially, autophagy blockage induced by 16E6/E7 knockdown. Immunoprecipitation assay showed that 16E7 interacted with Atg9B and dual-luciferase reporter system revealed that 16E6 most likely regulated -1750 to -2000 nt in Atg9B and -1800 to -2000 nt in LAMP1 promoter region. CONCLUSIONS: Our findings verified that 16E6/E7 activated autophagy via accelerating autophagosome formation and degradation, and Atg9B and LAMP1 were involved in the process of 16E6/E7 modulating autophagy, suggesting that targeting autophagy may be a potential approach in cervical cancer therapeutics.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Papillomavirus Humano 16/patogenicidade , Glicoproteínas de Membrana Associadas ao Lisossomo/genética , Proteínas de Membrana/genética , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Infecções por Papillomavirus/genética , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/virologia , Autofagossomos/metabolismo , Autofagia , Proteínas Relacionadas à Autofagia/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HEK293 , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/metabolismo , Humanos , Glicoproteínas de Membrana Associadas ao Lisossomo/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
16.
Microb Pathog ; 132: 162-165, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054871

RESUMO

Head and neck cancers (HNCs) are a major health problem and a leading cause of morbidity and mortality worldwide. More than 90% of these tumours are head and neck squamous cell carcinomas (HNSCCs). Amongst the common risk factors for HNCs (tobacco and alcohol use), there is a strong association of human papillomavirus (HPV) with HNSCCs. HPV type 16 (HPV 16), the major high-risk HPV type, is most commonly associated with HPV-driven HNSCCs. The promiscuous nature of the major HPV oncogene, E7, allows its interaction with a myriad of host proteins including STING, a component of the viral DNA-sensing cyclic GMP-AMP synthase (cGAS) - stimulator of interferon genes (STING) machinery. Sensing of viral DNA by the cGAS-STING machinery results in a type I interferon (IFN)-mediated anti-viral response. Amelioration of IFN responses resulting from the direct blockade of STING by E7 was first demonstrated in high-risk HPV type 18 (HPV 18) positive (+) cervical squamous cell carcinoma (CESC) cells. However, the role of E7 from HPV 16 (HPV 16E7) in antagonising cGAS-STING responses have not been investigated, let alone in the context of HNSCCs. Here, we show that HPV 16E7+, but not HPV 16E7 negative (-), HNSCC cells respond poorly to cGAS-STING activation stimulus. We further confirm that this inhibition occurred via the highly conserved LXCXE motif in 16E7. This finding contributes to the better understanding of role of high-risk HPV E7 in blocking cGAS-STING pathway, especially in the context of HNSCCs.


Assuntos
DNA Viral/isolamento & purificação , Neoplasias de Cabeça e Pescoço/virologia , Papillomavirus Humano 16/genética , Nucleotidiltransferases/genética , Infecções por Papillomavirus/virologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia , Linhagem Celular Tumoral , DNA Viral/genética , Regulação Viral da Expressão Gênica , Neoplasias de Cabeça e Pescoço/complicações , Papillomavirus Humano 16/metabolismo , Humanos , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/complicações , Carcinoma de Células Escamosas de Cabeça e Pescoço/complicações
17.
Sci Rep ; 9(1): 7438, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092861

RESUMO

The human protein tyrosine phosphatase non-receptor type 3 (PTPN3) is a PDZ (PSD-95/Dlg/ZO-1) domain-containing phosphatase with a tumor-suppressive or a tumor-promoting role in many cancers. Interestingly, the high-risk genital human papillomavirus (HPV) types 16 and 18 target the PDZ domain of PTPN3. The presence of a PDZ binding motif (PBM) on E6 confers interaction with a number of different cellular PDZ domain-containing proteins and is a marker of high oncogenic potential. Here, we report the molecular basis of interaction between the PDZ domain of PTPN3 and the PBM of the HPV E6 protein. We combined biophysical, NMR and X-ray experiments to investigate the structural and functional properties of the PDZ domain of PTPN3. We showed that the C-terminal sequences from viral proteins encompassing a PBM interact with PTPN3-PDZ with similar affinities to the endogenous PTPN3 ligand MAP kinase p38γ. PBM binding stabilizes the PDZ domain of PTPN3. We solved the X-ray structure of the PDZ domain of PTPN3 in complex with the PBM of the HPV E6 protein. The crystal structure and the NMR chemical shift mapping of the PTPN3-PDZ/peptide complex allowed us to pinpoint the main structural determinants of recognition of the C-terminal sequence of the E6 protein and the long-range perturbations induced upon PBM binding.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 18/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 3/metabolismo , Proteínas Repressoras/metabolismo , Sequência de Aminoácidos , Cristalografia por Raios X , Humanos , Ligantes , Proteína Quinase 12 Ativada por Mitógeno/metabolismo , Domínios PDZ , Infecções por Papillomavirus/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Ligação Proteica , Estabilidade Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 3/química , Proteína Tirosina Fosfatase não Receptora Tipo 3/genética , Relação Estrutura-Atividade
18.
Viruses ; 11(4)2019 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013597

RESUMO

Papillomaviruses replicate and cause disease in stratified squamous epithelia. Epithelial differentiation is essential for the progression of papillomavirus replication, but differentiation is also impaired by papillomavirus-encoded proteins. The papillomavirus E6 and E7 oncoproteins partially inhibit and/or delay epithelial differentiation and some of the mechanisms by which they do so are beginning to be defined. This review will outline the key features of the relationship between HPV infection and differentiation and will summarize the data indicating that papillomaviruses alter epithelial differentiation. It will describe what is known so far and will highlight open questions about the differentiation-inhibitory mechanisms employed by the papillomaviruses.


Assuntos
Diferenciação Celular , Células Epiteliais/citologia , Papillomavirus Humano 16/metabolismo , Animais , Transformação Celular Viral , Células Epiteliais/virologia , Humanos , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Replicação Viral
19.
J Cutan Pathol ; 46(8): 591-598, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30972814

RESUMO

BACKGROUND: Several studies have reported the oncogenic role of human papillomavirus (HPV) in non-melanoma skin cancer (NMSC) carcinogenesis. Considering that HPV could affect tumor protein 53 (TP53) degradation via E6 oncoprotein, we evaluated the expression of TP53 according to HPV infection and E6 expression. METHODS: Biopsy specimens from 79 NMSCs (28 squamous cell carcinomas, 21 keratoacanthomas and 30 basal cell carcinomas) were enrolled. Nested PCR was used to detect mucosal HPV (mHPV) DNA. Genotyping was performed by reverse line hybridization. Expression of TP53 and E6 was evaluated by immunohistochemistry. RESULTS: mHPVs were detected in 34.2% (27/79) of NMSC, with 92.6% (25/27) of high-risk HPV (HR-HPV) types. HPV16-E6-positive expression was observed in all HPV16-positive samples. TP53 high expression was found in 51.4% (37/72) of specimens. In this group, 78.4% were HPV-negative (P = 0.014). TP53 expression was negative in 8/10 of HPV E6-positive specimens. Multivariate analysis showed that TP53 was associated with HPV infection independently of histopathologic type (P = 0.005). CONCLUSION: This study showed a high prevalence of mHPV in NMSC. Active infections assessed by E6 expression are associated with loss of p53 function, highlighting the involvement of mHPV in NMSC carcinogenesis.


Assuntos
Regulação Neoplásica da Expressão Gênica , Regulação Viral da Expressão Gênica , Papillomavirus Humano 16/metabolismo , Proteínas Oncogênicas Virais/biossíntese , Infecções por Papillomavirus , Proteínas Repressoras/biossíntese , Neoplasias Cutâneas , Proteína Supressora de Tumor p53/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/virologia , Tunísia/epidemiologia
20.
Proc Natl Acad Sci U S A ; 116(14): 7033-7042, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30894485

RESUMO

High-risk human papillomavirus (HPV) E7 proteins enable oncogenic transformation of HPV-infected cells by inactivating host cellular proteins. High-risk but not low-risk HPV E7 target PTPN14 for proteolytic degradation, suggesting that PTPN14 degradation may be related to their oncogenic activity. HPV infects human keratinocytes but the role of PTPN14 in keratinocytes and the consequences of PTPN14 degradation are unknown. Using an HPV16 E7 variant that can inactivate retinoblastoma tumor suppressor (RB1) but cannot degrade PTPN14, we found that high-risk HPV E7-mediated PTPN14 degradation impairs keratinocyte differentiation. Deletion of PTPN14 from primary human keratinocytes decreased keratinocyte differentiation gene expression. Related to oncogenic transformation, both HPV16 E7-mediated PTPN14 degradation and PTPN14 deletion promoted keratinocyte survival following detachment from a substrate. PTPN14 degradation contributed to high-risk HPV E6/E7-mediated immortalization of primary keratinocytes and HPV+ but not HPV- cancers exhibit a gene-expression signature consistent with PTPN14 inactivation. We find that PTPN14 degradation impairs keratinocyte differentiation and propose that this contributes to high-risk HPV E7-mediated oncogenic activity independent of RB1 inactivation.


Assuntos
Diferenciação Celular , Transformação Celular Viral , Papillomavirus Humano 16/metabolismo , Queratinócitos/enzimologia , Proteínas E7 de Papillomavirus/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteólise , Linhagem Celular , Sobrevivência Celular , Regulação da Expressão Gênica , Papillomavirus Humano 16/genética , Humanos , Queratinócitos/patologia , Queratinócitos/virologia , Proteínas E7 de Papillomavirus/genética , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas de Ligação a Retinoblastoma/genética , Proteínas de Ligação a Retinoblastoma/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...