RESUMEN
Introduction: Infection with Human Papillomavirus (HPV) is a recognized risk factor for Chlamydia trachomatis (CT) infection and vice versa. Coinfection of HPV and CT in women is a very common and usually asymptomatic finding that has been linked to increased risk of cervical cancer. It has been demonstrated that CT facilitates the entry of multiple high risk HPV genotypes, leading to damage of the mucosal barrier and interfering with immune responses and viral clearance, which ultimately favours viral persistence and malignant transformation. Although the facilitating effects elicited by CT infection on viral persistence have been reported, little is known about the consequences of HPV infection on CT development. Methods: Herein, we took advantage of a genetically modified human cervical cell line co-expressing HPV-16 major oncogenic proteins E6 and E7, as an experimental model allowing to investigate the possible effects that HPV infection would have on CT development. Results and discussion: Our results show that CT infection of HPV-16 E6E7 expressing cells induced an upregulation of the expression of E6E7 oncoproteins and host cell inhibitory molecules PD-L1, HVEM and CD160. Additionally, smaller chlamydial inclusions and reduced infectious progeny generation was observed in E6E7 cells. Ultrastructural analysis showed that expression of E6 and E7 did not alter total bacterial counts within inclusions but resulted in increased numbers of reticulate bodies (RB) and decreased production of infectious elementary bodies (EB). Our results indicate that during CT and HPV coinfection, E6 and E7 oncoproteins impair RB to EB transition and infectious progeny generation. On the other hand, higher expression of immune inhibitory molecules and HPV-16 E6E7 are cooperatively enhanced in CT-infected cells, which would favour both oncogenesis and immunosuppression. Our findings pose important implications for clinical management of patients with HPV and CT coinfection, suggesting that screening for the mutual infection could represent an opportunity to intervene and prevent severe reproductive health outcomes, such as cervical cancer and infertility.
RESUMEN
Persistent high-risk human papillomavirus infection is the main risk factor for cervical cancer establishment, where the viral oncogenes E6 and E7 promote a cancerous phenotype. Metabolic reprogramming in cancer involves alterations in glutamine metabolism, also named glutaminolysis, to provide energy for supporting cancer processes including migration, proliferation, and production of reactive oxygen species, among others. The aim of this work was to analyze the effect of HPV16 E6 and E7 oncoproteins on the regulation of glutaminolysis and its contribution to cell proliferation. We found that the E6 and E7 oncoproteins exacerbate cell proliferation in a glutamine-dependent manner. Both oncoproteins increased the levels of transporter SNAT1, as well as GLS2 and GS enzymes; E6 also increased LAT1 transporter protein levels, while E7 increased ASCT2 and xCT. Some of these alterations are also regulated at a transcriptional level. Consistently, the amount of SNAT1 protein decreased in Ca Ski cells when E6 and E7 expression was knocked down. In addition, we demonstrated that cell proliferation was partially dependent on SNAT1 in the presence of glutamine. Interestingly, SNAT1 expression was higher in cervical cancer compared with normal cervical cells. The high expression of SNAT1 was associated with poor overall survival of cervical cancer patients. Our results indicate that HPV oncoproteins exacerbate glutaminolysis supporting the malignant phenotype.
Asunto(s)
Glutamina , Neoplasias del Cuello Uterino , Femenino , Humanos , Proliferación Celular , Papillomavirus Humano 16/genética , Proteínas E7 de Papillomavirus/genética , Sistema de Transporte de Aminoácidos A/metabolismoRESUMEN
Canis familiaris, Felis catus, and human papillomavirus are nonenveloped viruses that share similarities in the initiation and development of cancer. For instance, the three species overexpress the oncoproteins E6 and E7, and Canis familiaris and human papillomavirus overexpress the E5 oncoprotein. These similarities in the pathophysiology of cancer among the three species are beneficial for treating cancer in dogs, cats, and humans. To our knowledge, this topic has not been reviewed so far. This review focuses on the information on cancer research in cats and dogs comparable to that being conducted in humans in the context of comparative pathology and biomarkers in canine, feline, and human cancer. We also focus on the possible benefit of treatment associated with the E5, E6, and E7 oncoproteins for cancer in dogs, cats, and humans.
RESUMEN
The Epstein-Barr Virus (EBV) is a gammaherpesvirus involved in the etiopathogenesis of a variety of human cancers, mostly of lymphoid and epithelial origin. The EBV infection participates in both cell transformation and tumor progression, also playing an important role in subverting immune responses against cancers. The homeostasis of the immune system is tightly regulated by inhibitory mechanisms affecting key immune effectors, such as T lymphocytes and NK cells. Collectively known as immune checkpoints, these mechanisms rely on a set of cellular receptors and ligands. These molecules may be candidate targets for immune checkpoints blockade-an emergent and promising modality of immunotherapy already proven to be valuable for a variety of human cancers. The EBV was lately suspected to interfere with the expression of immune checkpoint molecules, notably PD-1 and its ligands, found to be overexpressed in cases of Hodgkin lymphoma, nasopharyngeal, and gastric adenocarcinomas associated with the viral infection. Even though there is compelling evidence showing that the EBV interferes with other immune checkpoint regulators (e.g., CTLA-4, LAG-3, TIM-3, and VISTA), the published data are still scarce. Herein, we discuss the current state of the knowledge on how the EBV interferes with the activity of immune checkpoints regulators, as well as its implications considering the immune checkpoints blockade for clinical management of the EBV-associated malignancies, notably lymphomas.
Asunto(s)
Infecciones por Virus de Epstein-Barr , Trastornos Linfoproliferativos , Neoplasias Gástricas , Herpesvirus Humano 4 , Humanos , Inhibidores de Puntos de Control Inmunológico , Ligandos , Trastornos Linfoproliferativos/complicacionesRESUMEN
Squamous cell carcinoma (SCC) is a common neoplastic skin disease that is highly prevalent in tropical countries. As the skin has a variety of cells, overexposure to environmental factors, such as ultraviolet light, can affect this organ, resulting in malignancies, such as cutaneous SCC, hemangioma, and hemangiosarcoma. SCC arises from keratinocytes in the skin and is locally invasive with low metastatic rates, commonly affecting unpigmented skin in sites with high exposure to sunlight, such as ventral regions. SCC has a variable etiology that is not well understood. Therefore, literature review aimed to critically evaluate the risk factors involved in the SCC development.(AU)
Asunto(s)
Animales , Perros , Rayos Ultravioleta , Carcinoma de Células Escamosas , Factores de Riesgo , Hemangioma , Hemangiosarcoma , NeoplasiasRESUMEN
Head and neck squamous cell carcinoma (HNSCC) cells that are positive for human papillomavirus (HPV+) favor mitochondrial metabolism rather than glucose metabolism. However, the involvement of mitochondrial metabolism in HNSCC HPV+ cells is still unknown. The aim of this work was to evaluate the role of E6 oncoproteins from HPV16 and HPV18 in the mitochondrial metabolism in an HNSCC model. We found that E6 from both viral types abates the phosphorylation of protein kinase B-serine 473 (pAkt), which is associated with a shift in mitochondrial metabolism. E6 oncoproteins increased the levels of protein subunits of mitochondrial complexes (I to IV), as well as the ATP synthase and the protein levels of the voltage dependent anion channel (VDAC). Although E6 proteins increased the basal and leak respiration, the ATP-linked respiration was not affected, which resulted in mitochondrial decoupling. This increase in leak respiration was associated to the induction of oxidative stress (OS) in cells expressing E6, as it was observed by the fall in the glutathione/glutathione disulfide (GSH/GSSG) rate and the increase in reactive oxygen species (ROS), carbonylated proteins, and DNA damage. Taken together, our results suggest that E6 oncoproteins from HPV16 and HPV18 are inducers of mitochondrial metabolism.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Neoplasias de Cabeza y Cuello/metabolismo , Mitocondrias/metabolismo , Proteínas Oncogénicas Virales/metabolismo , Papillomaviridae/química , Proteínas Represoras/metabolismo , Neoplasias de Cabeza y Cuello/virología , Humanos , Mitocondrias/virología , Papillomaviridae/metabolismo , Células Tumorales CultivadasRESUMEN
HPV testing is a better alternative for cervical cancer screening, but additional procedures are required for triage of HPV positive women. HPV encoded oncoproteins E6 and E7, as the main effectors of HPV carcinogenicity represent promising triage alternatives. To evaluate performance of the test, we included 155 women from a screening study and 59 from the same referral population attending colposcopy and with precancerous lesions. All were HPV-tested with HC2 and genotyped with LiPA, and cervical swabs were tested for HPV16/18 E6 oncoproteins. Histologic specimens were reviewed and adjudicated using p16 immunohistochemistry and 55 women had confirmed histologic HSIL, 31 (56.3%) associated with HPV 16/18, 23 with other HPV types and one HPV negative. Sensitivity and specificity were estimated with histologic HSIL/cancer as gold standard. E6 oncoprotein was detectable in all but one HSIL and in all cancers where HPV16/18 DNA was detected, but in none of the cases associated with other HPV types or HPV negatives. Among the few HPV16/18 DNA positive subjects initially without HSIL (n = 4) who were E6 oncoprotein positive, precancer was detected during follow-up in 2 out of 3 with available information. Estimated sensitivity for HPV16/18-related HSIL+ was 96.8% (95%CI = 83.8-99.8) and for all HSIL+ regardless of HPV type it was 56.4% (95%CI = 43.3-68.6). Specificity was 97.5% (95%CI = 93.7-99.0). E6 oncoprotein proved as a highly sensitive and specific marker for detection of HPV16/18-related HSIL lesions in this Honduran population with limited previous screening and may be useful as a triage method in screening programs, particularly in low income countries.
Asunto(s)
Proteínas de Unión al ADN/genética , Detección Precoz del Cáncer/métodos , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/diagnóstico , Proteínas Represoras/genética , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adulto , ADN Viral/genética , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/virología , Reacción en Cadena de la Polimerasa/métodos , Lesiones Precancerosas/diagnóstico , Lesiones Precancerosas/virología , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/virologíaRESUMEN
PURPOSE: Evaluate the presence of human papillomavirus (HPV) in biopsies of Brazilian patients with lung cancer and also the expression of the E6 and E7 oncoproteins. HPV is widely known as an important condition for cervical cancer although evidence today shows it is associated with several other types of cancer and may also be involved in lung cancer development. However, there are some divergences regarding the presence and activity of HPV in lung carcinogenesis. METHODS: The detection of HPV was performed by PCR, followed by genotype and immunohistochemical evaluation of E6 and E7 HPV type specific, from 63 patients. RESULTS: HPV was found to be present in 33 of the 63 samples, and types 16 and 18 were detected with frequencies of 81% (27/33) and 19% (6/33), respectively. About the presence of the virus in different histological types of tumors, HPV was detected in squamous cell carcinoma (39.39%), followed by adenocarcinoma (33.33%) and small cell carcinoma (18.18%) and large cell carcinoma (9.1%). The presence of the E6 (antibody anti-HPV 16 and anti-HPV 18) and E7 (antibody anti-HPV 16 and anti-HPV 18) oncoproteins was detected by immunohistochemical stain technique in 28/33 samples and 25/33 samples, respectively. CONCLUSIONS: Our results suggest that the lung tumor patients have high prevalence of HPV and the virus is not only present but also active in tumor cells. Therefore, the HPV is probably playing a role in lung carcinogenesis.
Asunto(s)
Neoplasias Pulmonares/etiología , Papillomaviridae , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Proteínas Oncogénicas Virales/genética , Proteínas Oncogénicas Virales/metabolismo , Papillomaviridae/clasificación , Papillomaviridae/genética , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Adulto JovenRESUMEN
La infección de transmisión sexual por el Virus del Papiloma Humano (VPH) es una de las más comunes en el mundo. Los VPH se clasifican en bajo riesgo y alto riesgo. Los VPH de bajo riesgo son los causantes de lesiones benignas como verrugas genitales y condilomas acuminados, mientras que los VPH de alto riesgo pueden originar la transformación maligna de las células del epitelio cervical por la acción de las oncoproteínas E6 y E7, lo que puede dar origen al cáncer de cuello uterino. La detección de los niveles de ARN mensajero (ARNm) de E6 y E7 de VPH en las células del epitelio cervical está siendo evaluada como un marcador predictivo del cáncer de cuello uterino como alternativa a las técnicas de detección del ADN de VPH. En este artículo se realizó una revisión crítica acerca de la relación existente entre la detección de la expresión de ARNm de E6 y E7 del virus del papiloma humano y el cáncer de cuello uterino. Además, se revisaron las técnicas aprobadas actualmente por la FDA (Food and Drug Administration) para la detección de ARNm de las oncoproteínas E6 y E7 de VPH y el estado del arte del VPH en Colombia.
The sexually transmitted infection by the Human Papillomavirus (HPV) is one of the most common in the world. Human papillomaviruses are classified as low risk and high risk. Low-risk HPVs are the cause of benign lesions such as genital warts and condylomata acuminata, while high-risk HPV types can cause malignant transformation of cervical epithelial cells by the action of oncoproteins E6 and E7, which could result in the development of cervical cancer. The detection of levels of HPV E6 and E7 mRNA (messenger RNA) in cervical epithelial cells is being evaluated as a predictive marker of cervical cancer as an alternative to HPV DNA detection techniques. In this article, a critical review was made about the relationship between the detection of E6 and E7 mRNA expression of human papillomavirus and cervical cancer. Furthermore, the techniques currently approved by the Food and Drug Administration (FDA) for the detection of mRNA from the HPV E6 and E7 oncoproteins and the state of the art of HPV in Colombia were reviewed.
A infecção sexualmente transmissível pelo Vírus do Papiloma Humano (HPV) é uma das mais comuns no mundo. Os HPV são classificados em tipos de baixo e de alto risco. Os HPV de baixo risco são a causa de lesões benignas, tais como verrugas genitais e condilomas acuminados, enquanto que os HPV de alto risco podem causar a transformação maligna das células do epitélio cervical pela ação das oncoproteínas E6 e E7, o que pode dar origem ao câncer de colo de útero. A detecção dos níveis de RNA Mensageiro (RNAm) E6 e E7 de HPV nas células do epitélio cervical está sendo avaliada como marcador preditivo do câncer de colo de útero como alternativa às técnicas de detecção de DNA do HPV. Neste artigo, foi realizada uma revisão crítica sobre a relação entre a detecção da expressão de RNAm E6 e E7 do vírus do papiloma humano e o câncer do colo de útero. Do mesmo modo, foram revisadas as técnicas aprovadas pela FDA (Food and Drug Administration) para detecção de ARNm das oncoproteínas E6 e E7 de HPV e o estado da arte do HPV na Colômbia.
Asunto(s)
Humanos , Enfermedades de Transmisión Sexual , Neoplasias del Cuello Uterino , Proteínas Oncogénicas , Biología Celular , Alphapapillomavirus , Virología , ADN , ARN Mensajero , Condiloma Acuminado , Causalidad , Células Epiteliales , NeoplasiasRESUMEN
High-risk human papillomavirus (HR-HPV) infection is not a sufficient condition for cervical cancer development because most infections are benign and naturally cleared. Epidemiological studies revealed that tobacco smoking is a cofactor with HR-HPV for cervical cancer initiation and progression, even though the mechanism by which tobacco smoke cooperates with HR-HPV in this malignancy is poorly understood. As HR-HPV E6/E7 oncoproteins overexpressed in cervical carcinomas colocalize with cigarette smoke components (CSC), in this study we addressed the signaling pathways involved in a potential interaction between both carcinogenic agents. Cervical cancer-derived cell lines, CaSki (HPV16; 500 copies per cell) and SiHa (HPV16; 2 copies per cell), were acutely exposed to CSC at various non-toxic concentrations and we found that E6 and E7 levels were significantly increased in a dose-dependent manner. Using a reporter construct containing the luciferase gene under the control of the full HPV16 long control region (LCR), we also found that p97 promoter activity is dependent on CSC. Non-synonymous mutations in the LCR-resident TPA (12-O-tetradecanoylphorbol 13-acetate)-response elements (TRE) had significantly decreased p97 promoter activation. Phosphoproteomic arrays and specific inhibitors revealed that CSC-mediated E6/E7 overexpression is at least in part reliant on EGFR phosphorylation. In addition, we showed that the PI3K/Akt pathway is crucial for CSC-induced E6/E7 overexpression. Finally, we demonstrated that HPV16 E6/E7 overexpression is mediated by JUN. overexpression, c-Jun phosphorylation and recruitment of this transcription factor to TRE sites in the HPV16 LCR. We conclude that acute exposure to tobacco smoke activates the transcription of HPV16 E6 and E7 oncogenes through p97 promoter activation, which involves the EGFR/PI3K/Akt/C-Jun signaling pathway activation in cervical cancer cells.
RESUMEN
ABSTRACT Objective: To evaluate the association between p53 polymorphisms and human papillomavirus (HPV) E6/E7 mRNA expression. Methods: We analyzed 175 cervical samples from women aged 16-69 years old who were tested for HPV E6/E7 mRNA expression (NucliSENS® EasyQ® HPV). The samples were divided into three groups: positive (n = 75) those with positive HPV E6/E7 mRNA expression and positive high-risk HPV Hybrid Capture (HR-HC) test; negative (n = 52) those with negative HPV E6/E7 mRNA expression and positive HR-HC; and control (n = 48) those with negative HPV E6/E7 mRNA expression and negative HR-HC. The p53 polymorphisms at codons 11, 72, and 248 were evaluated through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The frequency of the arginine/arginine homozygous genotype at codon 72 was significantly higher in the positive (49.3%) than in the negative (32.7%) and control groups (20.8%, p = 0.002*). The frequency of the arginine allele was also significantly higher in the positive (67.3%) than in the negative (53.8%) and control groups (38.5%, p < 0.001*). The arginine/arginine homozygous genotype was significantly associated with positive HPV E6/E7 mRNA expression (positive group) compared with negative and control groups (odds ratio: 2.633; 95% CI, 1.399-4.954, p = 0.003). The frequency of arginine/arginine homozygous genotype at codon 72 remained significantly more frequent in the positive group of women aged ≥30 years than in the other two groups. Conclusion: The presence of the p53 arginine/arginine homozygous genotype at codon 72 was significantly associated with the positive HPV E6/E7 mRNA expression.
Asunto(s)
Humanos , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Adulto Joven , Papillomaviridae/genética , ARN Mensajero/metabolismo , Proteínas Oncogénicas Virales/genética , Displasia del Cuello del Útero/virología , Infecciones por Papillomavirus/virología , Proteínas E7 de Papillomavirus/genética , Arginina/genética , Polimorfismo de Longitud del Fragmento de Restricción , Codón , ARN Viral , Neoplasias del Cuello Uterino/virología , Reacción en Cadena de la Polimerasa , Proteína p53 Supresora de Tumor/genética , GenotipoRESUMEN
OBJECTIVE: To evaluate the association between p53 polymorphisms and human papillomavirus (HPV) E6/E7 mRNA expression. METHODS: We analyzed 175 cervical samples from women aged 16-69 years old who were tested for HPV E6/E7 mRNA expression (NucliSENS® EasyQ® HPV). The samples were divided into three groups: positive (n=75) those with positive HPV E6/E7 mRNA expression and positive high-risk HPV Hybrid Capture (HR-HC) test; negative (n=52) those with negative HPV E6/E7 mRNA expression and positive HR-HC; and control (n=48) those with negative HPV E6/E7 mRNA expression and negative HR-HC. The p53 polymorphisms at codons 11, 72, and 248 were evaluated through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The frequency of the arginine/arginine homozygous genotype at codon 72 was significantly higher in the positive (49.3%) than in the negative (32.7%) and control groups (20.8%, p=0.002*). The frequency of the arginine allele was also significantly higher in the positive (67.3%) than in the negative (53.8%) and control groups (38.5%, p<0.001*). The arginine/arginine homozygous genotype was significantly associated with positive HPV E6/E7 mRNA expression (positive group) compared with negative and control groups (odds ratio: 2.633; 95% CI, 1.399-4.954, p=0.003). The frequency of arginine/arginine homozygous genotype at codon 72 remained significantly more frequent in the positive group of women aged ≥30 years than in the other two groups. CONCLUSION: The presence of the p53 arginine/arginine homozygous genotype at codon 72 was significantly associated with the positive HPV E6/E7 mRNA expression.
Asunto(s)
Proteínas Oncogénicas Virales/genética , Papillomaviridae/genética , Proteínas E7 de Papillomavirus/genética , Infecciones por Papillomavirus/virología , ARN Mensajero/metabolismo , Proteína p53 Supresora de Tumor/genética , Displasia del Cuello del Útero/virología , Neoplasias del Cuello Uterino/virología , Adolescente , Adulto , Anciano , Arginina/genética , Codón , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , ARN Viral , Adulto JovenRESUMEN
As oncoproteínas E6 e E7 do Papilomavírus Humano (HPV) estão envolvidas na desregulação do sistema imune inato, provocando alterações na expressão dos receptores do tipo Toll (TLR). Considerando-se a função da via de sinalização iniciada por TLR, haveria uma vantagem para o vírus capaz de manipular a resposta desta via de modo que possa persistir nas células sem ser detectado pelo sistema imune ou ainda modulando essa resposta e criando um ambiente mais propício à manutenção da infecção. No entanto, muitos dos mecanismos que levam à eliminação da infecção ou persistência do HPV ainda são pouco conhecidos. O objetivo principal desse trabalho é investigar o papel das vias de TLR no processo de carcinogênese mediado por HPV. Inicialmente, foi analisada a expressão de genes da via de TLR em linhagens de tumores cervicais e em células expressando as oncoproteínas virais. Foram identificados vários genes diferencialmente expressos entre linhagens de células tumorais e queratinócitos normais, incluindo moléculas adaptadoras da via de TLR e genes associados à via da MAP quinase, ativação de NFkappaB e resposta imune antiviral. Cerca de 90% destes genes foram regulados negativamente. Entre eles, destacamos HMGB1, que apesar de possuir menos RNAm nas células tumorais possui um nível proteico muito maior, além de ter-se mostrado de grande importância para a viabilidade e proliferação das células tumorais, conforme demonstrado através de experimentos de supressão gênica. Em conjunto, os nossos dados indicam que E6 e E7 de HPVs de alto risco inibem proteínas da via de sinalização de TLR
Previous studies have shown that E6 and E7 HPV oncoproteins are involved in innate immune system dysregulation, causing alterations on Toll-like receptors (TLR) expression. Considering TLR pathway function, it would be advantageous for a virus to manipulate the response of this pathway so it can persist in cells without being detected by the immune system or to modulate this response to create a better environment for persistence of infection. However, many of the mechanisms leading to HPV infection clearance or persistence are still unknown and matter of active investigation. We analyzed in cervical cancer cell lines expression of genes from TLR pathway; several were differentially expressed between tumor cells lines and normal keratinocytes, including TLR adaptors molecules and genes associated with MAP kinase pathway, NFkappaB activation and antiviral immune response. About 90% of these genes were down regulated. Among them, we selected HMGB1 for further characterization due to its interference with tumor cell viability and proliferation. Altogether, our data indicate that high risk HPV E6 and E7 can inhibit TLR signaling pathway
Asunto(s)
Papillomaviridae/patogenicidad , Receptor Toll-Like 1/análisis , Expresión Génica , Proteínas Oncogénicas/farmacocinética , Factor 88 de Diferenciación Mieloide/genética , Carcinogénesis/metabolismo , Inmunidad Innata/inmunologíaRESUMEN
Cell signaling pathways are the mechanisms by which cells transduce external stimuli, which control the transcription of genes, to regulate diverse biological effects. In cancer, distinct signaling pathways, such as the Wnt/ß-catenin pathway, have been implicated in the deregulation of critical molecular processes that affect cell proliferation and differentiation. For example, changes in ß-catenin localization have been identified in Human Papillomavirus (HPV)-related cancers as the lesion progresses. Specifically, ß-catenin relocates from the membrane/cytoplasm to the nucleus, suggesting that this transcription regulator participates in cervical carcinogenesis. The E6 and E7 oncoproteins are responsible for the transforming activity of HPV, and some studies have implicated these viral oncoproteins in the regulation of the Wnt/ß-catenin pathway. Nevertheless, new interactions of HPV oncoproteins with cellular proteins are emerging, and the study of the biological effects of such interactions will help to understand HPV-related carcinogenesis. Viruses 2015, 7 4735 This review addresses the accumulated evidence of the involvement of the HPV E6 and E7 oncoproteins in the activation of the Wnt/ß-catenin pathway.
Asunto(s)
Interacciones Huésped-Patógeno , Proteínas Oncogénicas Virales/metabolismo , Papillomaviridae/fisiología , Vía de Señalización Wnt , Animales , Transformación Celular Viral , HumanosRESUMEN
Oncogenes are the primary candidates for target-directed therapy, given that they are involved directly in the progression and resistance of tumors. However, the appearance of point mutations can hinder the treatment of patients with these new molecules, raising costs and the need to development new analogs that target the novel mutations. Based on an analysis of homologies, the present study discusses the possibility of predicting the failure of a protein as a pharmacological target, due to its similarities with retrovirus sequences, which have extremely high mutation rates. This analysis was based on the molecular evidence available in the literature, and widely-used and well-established PSI-BLAST, with two iterations and maximum of 500 aligned sequences. The possibility of predicting which newly-discovered genes involved in tumor progression would likely result in the failure of targeted therapy, using free, simple and automated bioinformatics tools, could provide substantial savings in the time and financial resources needed for long-term drug development.
RESUMEN
O Papilomavírus Bovino do tipo 1 (BPV-1) causa fibropapilomas em bovinos e sarcóide em equinos, associados à expressão de oncoproteínas virais, principalmente E6 e E7. A purificação de oncoproteínas a partir de sistema recombinante possibilita seu estudo. Os objetivos foram expressar o gene E6 do BPV-1, purificar e analisar in silico a proteína recombinante obtida. O amplificado foi clonado em E. coli e os plasmídeos foram sequenciados, confirmando a matriz correta de leitura. Após indução da expressão, a proteína recombinante foi identificada e purificada. A microscopia eletrônica mostrou a formação de corpúsculos de inclusão. As análises in silico apontaram as mutações das sequências gênica e proteica de E6-1 em relação às depositadas. Foi realizada a predição tridimensional da estrutura da proteína recombinante e identificadas as regiões conservadas, antigênicas e capazes de realizar ligações cátion-p. Logo, a proteína recombinante E6 do BPV-1 foi obtida e purificada com sucesso, possibilitando o início de novos experimentos e estudos mais detalhados.
Bovine Papillomavirus type 1 (BPV-1) causes fibropapillomas in cattle and sarcoid in equines, associated with the expression of viral oncoproteins, E6 and E7 particularly. Purification of oncoproteins from recombinant system allows their study. The aim of this study was cloning and expressing BPV-1 E6 gene, purify and analyze in silico recombinant protein. Amplicon was cloned into E. coli and the plasmids were sequenced to confirm the correct reading frame. After induction of expression, the recombinant protein was identified and purified. Electron microscopy showed the inclusion bodies formation. In silico analysis showed mutations in E6-1 gene and protein sequences when there were compared to sequences available in current database. Three-dimensional structure prediction of the recombinant protein was performed and conserved, antigenic and cation-p interaction regions were identified. Therefore, BPV-1 E6 recombinant protein was obtained and successfully purified enabling new experiments and more detailed studies.
Asunto(s)
Animales , Bovinos , Caballos/virología , Papillomavirus Bovino 1/genética , Proteínas Oncogénicas/genética , Proteínas Recombinantes/genética , Infecciones por Papillomavirus/veterinaria , Microscopía Electrónica/veterinariaRESUMEN
O cancêr cervical é o segundo câncer mais comum entre mulheres no mundo. A maioria dos casos ( 83%) ocorre em países em desenvolvimento, onde são encontrados em estágios relativamente avançados, e consequentemente, a sobrevida média é de cerca de 49% após cinco anos. Portanto uma vacina eficaz contra as infecções pelo HPV pode levar ao controle do câncer do colo do útero. Apesar de prevenir, a vacina profilática não é acessível em função do alto custo, além de não eliminar o vírus em mulheres já infectadas pelo HPV. Assim, propusemos o desenvolvimento de uma vacina terapêutica eficaz utilizando duas abordagens : VLPs ( virus- like particles) quiméricas, que poderiam apresentar propriedades profiláticas e terapeuticas, obtidas da fusão das proteínas L1 e E7; proteinas quiméricas obtidas a partir da fusão de epitópos das proteínas E6 e E7 e do HPV 16 com e sem ubiquitina...
Cervical cancer is the second most common cancer among women in relatively advanced stages and, consequently, the median survival is about 49% after five years.Therefore, an effective vaccine against HPV infections can lead to control of cancer of the cervix. Although preventable, the prophylactic HPV vaccine against HPV vaccine is not acessible to all due to their high cost and in addition the vaccine does not eliminate the HPV in infect women. We have therefore proposed the development of effective therapeutic vacines using two approaches: chimeric VLPs ( virus - like particles), endowed with prophylatic and therapeutic properties, obtained from the fusion protein L1 andE7; chimeric proteins derived from the fusion of epitopes of proteins E6 and E7 of HPV 16 with and without ubiquitin...