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1.
PLoS Pathog ; 16(5): e1008502, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32407379

RESUMO

Viruses have developed different strategies to escape from immune response. Among these, viral non-coding RNAs are invisible to the immune system and may affect the fate of the host cell. Bovine leukemia virus (BLV) encodes both short (miRNAs) and long (antisense AS1 and AS2) non-coding RNAs. To elucidate the mechanisms associated with BLV non-coding RNAs, we performed phenotypic and transcriptomic analyzes in a reverse genetics system. RNA sequencing of B-lymphocytes revealed that cell proliferation is the most significant mechanism associated with ablation of the viral non-coding RNAs. To assess the biological relevance of this observation, we determined the cell kinetic parameters in vivo using intravenous injection of BrdU and CFSE. Fitting the data to a mathematical model provided the rates of cell proliferation and death. Our data show that deletion of miRNAs correlates with reduced proliferation of the infected cell and lack of pathogenesis.


Assuntos
Linfócitos B , Transformação Celular Viral , Vírus da Leucemia Bovina , MicroRNAs , RNA Antissenso , RNA Viral , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfócitos B/virologia , Bovinos , Proliferação de Células , Vírus da Leucemia Bovina/genética , Vírus da Leucemia Bovina/metabolismo , Vírus da Leucemia Bovina/patogenicidade , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA Viral/genética , RNA Viral/metabolismo
2.
J Cancer Res Clin Oncol ; 146(7): 1677-1692, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32372145

RESUMO

PURPOSE: HPV is involved in the development of some head and neck squamous-cell carcinomas (HNSCC). It was suggested that only transcriptionally active virus can induce carcinogenesis, therefore, the aim of our study was to analyze the frequency of active HPV infection, virus type, and its prognostic role in HNSCC patients. METHODS: Status of active HPV infection was assessed for 155 HNSCC patients based on p16 expression and HPV DNA presence. Univariate and multivariate analyses with Cox proportional regression model were performed to select independent prognostic factors. RESULTS: Active HPV infection was detected in 20.65% of patients. We identified 16.0, 40.9 and 1.7% of HPV positive oral cavity, oropharyngeal, and laryngeal cancer cases, respectively. HPV16 was dominant (81.25%) followed by HPV35 (9.38%) and double infections with HPV16 and 35 (6.25%) or HPV35 and 18 (3.12%). Patients with active HPV infection demonstrated significantly higher survival than HPV negative ones (OS 80.89% vs. 37.08%, p = 0.000; DFS 93.0% vs. 53.35%, p = 0.000, respectively). Longer OS and DFS were maintained for infected patients when oropharyngeal and non-oropharyngeal cases were analyzed separately. Interestingly, all patients infected with other than HPV16 types survived 5 years without cancer progression. In the analyzed group of 155 patients the strongest independent favourable prognostic factor for both OS and DFS was HPV presence. CONCLUSIONS: High prevalence of HPV-driven HNSCC (mostly within oropharynx) was detected, with HPV16 type the most frequent, followed by HPV35 and HPV18. The presence of active HPV infection improved survival of both oropharyngeal and non-oropharyngeal cancer patients and should be taken into account in treatment planning.


Assuntos
Infecções por Papillomavirus/virologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Idoso , Alphapapillomavirus/classificação , Alphapapillomavirus/fisiologia , Transformação Celular Viral , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Imunofluorescência , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/diagnóstico , Reação em Cadeia da Polimerase , Prevalência , Modelos de Riscos Proporcionais , Carcinoma de Células Escamosas de Cabeça e Pescoço/etiologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Ativação Viral
3.
BMC Bioinformatics ; 21(Suppl 7): 152, 2020 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-32366259

RESUMO

BACKGROUND: Cervical cancer is the fourth most common tumor in women worldwide, mostly resulting from high-risk human papillomavirus (HR-HPV) with persistent infection. RESULTS: The present discoveries are comprised of the following: (i) A total of 16.64% of the individuals were positive for HR-HPV infection, with 13.04% having a single HR-HPV type and 3.60% having multiple HR-HPV types. (ii) Cluster analysis showed that the infection rate trends of HPV31 and HPV33 in all infections as well as HPV33 and HPV35 in single infections in precancerous stages were very similar. (iii) The single/multiple infection proportions of HR-HPV demonstrated a trend that the multiple infections rates of HR-HPV increased as the disease developed. CONCLUSIONS: The HR-HPV prevalence in outpatients was 16.64%, and the predominant HR-HPV types in the study were HPV52, HPV58 and HPV16. HR-HPV subtypes with common biological properties had similar infection rate trends in precancerous stages. Especially, as the disease development of precancer evolved, defense against HPV infection broke, meanwhile, the potential of more HPV infection increased, which resulted in increase of multiple infections of HPV.


Assuntos
Carcinogênese , Modelos Biológicos , Papillomaviridae , Infecções por Papillomavirus/complicações , Neoplasias do Colo do Útero/etiologia , Transformação Celular Viral , Feminino , Humanos , Infecções por Papillomavirus/epidemiologia , Prevalência , Neoplasias do Colo do Útero/patologia
4.
BMC Med Genet ; 21(1): 48, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32138690

RESUMO

BACKGROUND: This study was aimed to investigate the regulatory role of microRNA-210 (miRNA-210) on the progression of liver cancer and Hepatitis B virus (HBV)-associated liver cancer. METHODS: The expression of miRNA-210 was detected in liver tissues of HBV-associated cirrhosis and liver cancer, and in HepG2 and HepG2.2.15 cells by qRT-PCR. MiRNA-210 was silenced in HepG2 and HepG2.2.15 cells by the transfection of miRNA-210 inhibitor. The cell viability and apoptosis was detected by MTT assay and Annexin V-fluorescein isothiocyanate/propidium iodide staining, respectively. The protein expression of EGR3 was detected by Western blot. The regulatory relationship between EGR3 and miRNA-210 was predicted by TargetScan and identified by Dual luciferase reporter gene assay. RESULTS: MiRNA-210 was overexpressed in the liver tissues of HBV-associated cirrhosis and liver cancer, and in HepG2 and HepG2.2.15 cells (P < 0.05). Silencing of miRNA-210 inhibited the viability and promoted the apoptosis of HepG2 and HepG2.2.15 cells (P < 0.05). EGR3 was a target of miRNA-210, which was down-regulated in the liver tissues of HBV-associated cirrhosis and liver cancer, and in HepG2 and HepG2.2.15 cells (P < 0.05). Silencing of miRNA-210 increased the mRNA and protein expression of EGR3 (P < 0.05). Silencing of EGR3 reversed the anti-tumor effect of miRNA-210 inhibitor on HepG2 and HepG2.2.15 cells (P < 0.05). CONCLUSIONS: Silencing of miRNA-210 inhibits the progression of liver cancer and HBV-associated liver cancer via up-regulating EGR3.


Assuntos
Carcinoma Hepatocelular/genética , Transformação Celular Viral/genética , Proteína 3 de Resposta de Crescimento Precoce/genética , Vírus da Hepatite B/fisiologia , Neoplasias Hepáticas/genética , MicroRNAs/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Estudos de Casos e Controles , Células Cultivadas , Progressão da Doença , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade
5.
Mem Inst Oswaldo Cruz ; 115: e190405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32187327

RESUMO

BACKGROUND: High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical cancer. Among them, types 16 and 18 are the most prevalent worldwide. The HPV genome encodes three oncoproteins (E5, E6, and E7) that possess a high transformation potential in culture cells when transduced simultaneously. In the present study, we analysed how these oncoproteins cooperate to boost key cancer cell features such as uncontrolled cell proliferation, invasion potential, and cellular redox state imbalance. Oxidative stress is known to contribute to the carcinogenic process, as reactive oxygen species (ROS) constitute a potentially harmful by-product of many cellular reactions, and an efficient clearance mechanism is therefore required. Cells infected with HR-HPVs can adapt to oxidative stress conditions by upregulating the formation of endogenous antioxidants such as catalase, glutathione (GSH), and peroxiredoxin (PRX). OBJECTIVES: The primary aim of this work was to study how these oncoproteins cooperate to promote the development of certain cancer cell features such as uncontrolled cell proliferation, invasion potential, and oxidative stress that are known to aid in the carcinogenic process. METHODS: To perform this study, we generated three different HaCaT cell lines using retroviral transduction that stably expressed combinations of HPV-18 oncogenes that included HaCaT E5-18, HaCaT E6/E7-18, and HaCaT E5/E6/E7-18. FINDINGS: Our results revealed a statistically significant increment in cell viability as measured by MTT assay, cell proliferation, and invasion assays in the cell line containing the three viral oncogenes. Additionally, we observed that cells expressing HPV-18 E5/E6/E7 exhibited a decrease in catalase activity and a significant augmentation of GSH and PRX1 levels relative to those of E5, E6/E7, and HaCaT cells. MAIN CONCLUSIONS: This study demonstrates for the first time that HPV-18 E5, E6, and E7 oncoproteins can cooperate to enhance malignant transformation.


Assuntos
Transformação Celular Viral/genética , Proteínas de Ligação a DNA/metabolismo , Papillomavirus Humano 18/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Linhagem Celular Tumoral/virologia , Proliferação de Células , Sobrevivência Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Oxirredução
6.
Nat Commun ; 11(1): 685, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32019925

RESUMO

IκB kinase 2 (IKK2) is well known for its pivotal role as a mediator of the canonical NF-κB pathway, which has important functions in inflammation and immunity, but also in cancer. Here we identify a novel and critical function of IKK2 and its co-factor NEMO in the activation of oncogenic c-Jun N-terminal kinase (JNK) signaling, induced by the latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV). Independent of its kinase activity, the TGFß-activated kinase 1 (TAK1) mediates LMP1 signaling complex formation, NEMO ubiquitination and subsequent IKK2 activation. The tumor progression locus 2 (TPL2) kinase is induced by LMP1 via IKK2 and transmits JNK activation signals downstream of IKK2. The IKK2-TPL2-JNK axis is specific for LMP1 and differs from TNFα, Interleukin-1 and CD40 signaling. This pathway mediates essential LMP1 survival signals in EBV-transformed human B cells and post-transplant lymphoma, and thus qualifies as a target for treatment of EBV-induced cancer.


Assuntos
Linfócitos B/virologia , Herpesvirus Humano 4/fisiologia , Quinase I-kappa B/metabolismo , MAP Quinase Quinase 4/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Transformação Celular Viral , Herpesvirus Humano 4/genética , Humanos , Quinase I-kappa B/genética , Linfoma/enzimologia , Linfoma/genética , Linfoma/metabolismo , MAP Quinase Quinase 4/genética , MAP Quinase Quinase Quinases/genética , Camundongos , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais
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.
Virchows Arch ; 476(3): 353-365, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31836926

RESUMO

Thirty years have passed since a possible association of Epstein-Barr virus (EBV) with gastric carcinoma was reported. We now know EBV-associated gastric carcinoma to be a specific subtype of gastric carcinoma. Global epigenetic methylation and counteraction of the antitumour microenvironment are two major characteristics of this subtype of gastric carcinoma. Recent development of therapeutic modalities for gastric carcinoma, such as endoscopic mucosal dissection and immune checkpoint inhibitor therapy, has made the presence of EBV infection a biomarker for the treatment of gastric carcinoma. This review presents a portrait of EBV-associated gastric carcinoma from initiation to maturity that we define as the 'gastritis-infection-cancer sequence', followed by its molecular abnormalities and interactions with immune checkpoint molecules and the microenvironment. EBV non-coding RNAs (microRNA and circular RNA) and exosomes derived from EBV-infected cells that were previously behind the scenes are now recognized for their roles in EBV-associated gastric carcinoma. The virus utilizes cellular machinery skilfully to control infected cells and their microenvironment. We should thus strive to understand virus-host interactions more fully in the following years to overcome this virus-driven subtype of gastric carcinoma.


Assuntos
Transformação Celular Viral/fisiologia , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Neoplasias Gástricas/virologia , Humanos
9.
Arch Virol ; 165(2): 313-320, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31813023

RESUMO

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that transforms primary B lymphocytes, yielding lymphoblastoid cell lines (LCLs). EBV-encoded nuclear antigen 2 (EBNA2) and EBV-encoded nuclear antigen leader protein (EBNALP) are the first viral products expressed after EBV infection of primary B lymphocytes and are essential for EBV-induced B-lymphocyte growth transformation. EBNA2 functions as a transcriptional activator of viral and cellular genes, with EBNALP as a coactivator for EBNA2-mediated transcriptional activation. We previously reported that mutant EBNALP with a C-terminal 10-amino-acid truncation loses the ability to coactivate, and has a dominant-negative effect on wild-type-EBNALP-mediated coactivation. However, the functional relevance of EBNALP in maintenance of LCL cell growth has not been investigated. To address this, we have constructed LCL-derived cell clones in which this dominant-negative form of EBNALP (DNLP) is conditionally expressed by the Cre-loxP system. We used these cells to evaluate the effect of DNLP expression on EBV-induced cell proliferation. After drug treatment, the DNLP-expressing LCL clones showed reduced cell proliferation and viability. These results indicate that EBNALP is critical for maintaining LCL growth and EBV-induced cell proliferation.


Assuntos
Linfócitos B/virologia , Proliferação de Células , Transformação Celular Viral , Antígenos Nucleares do Vírus Epstein-Barr/metabolismo , Expressão Gênica , Herpesvirus Humano 4/crescimento & desenvolvimento , Proteínas Mutantes/metabolismo , Proteínas Virais/metabolismo , Linhagem Celular , Antígenos Nucleares do Vírus Epstein-Barr/genética , Humanos , Proteínas Mutantes/genética , Proteínas Virais/genética
10.
PLoS One ; 14(12): e0226105, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31805146

RESUMO

Due to the limited host range of orf virus (ORFV), primary cells derived from its natural hosts, such as goats and sheep, are recommended for isolation and propagation of wild type ORFV. This situation limits the option for the study of virus-host interaction during ORFV infection since primary cells only support a few numbers of passages. SV40 T antigen is a viral oncoprotein that can abrogate replicative senescence, leading to an extended life span of cells. In this study, the transformation of two goat primary cells, fibroblast (FB) and testis (GT) cells, were achieved by stably expressing SV40 T antigen using the lentiviral technique. The presence of the gene encoding SV40 T antigen was validated by polymerase chain reaction (PCR) and western blot analyses. As evidenced by immunofluorescent microscopy, the two types of cells expressing SV40 T antigen (namely, FBT and GTT) were purified to homogeneity. Moreover, faster growth kinetics and a lower serum dependency were noticed in FBT and GTT, as compared with their counterpart parental cells. FBT and GTT remain permissive and can form plaque of ORFV, despite with different profiles; generally speaking, with SV40 T expression, ORFV forms plaques with smaller size and distinct margin. Most importantly, the prolonged life span of goat FBT and GTT serves as an ideal cell culture resource for ORFV isolation from the field, studies of ORFV pathogenesis and efficient vaccine development.


Assuntos
Antígenos Virais de Tumores/genética , Transformação Celular Viral/genética , Vírus do Orf/fisiologia , Vírus 40 dos Símios/imunologia , Replicação Viral/genética , Animais , Linhagem Celular , Expressão Gênica , Cabras , Humanos
11.
Breast Cancer Res ; 21(1): 152, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881983

RESUMO

BACKGROUND: PIK3CA mutations are frequent in human breast cancer. Pik3caH1047R mutant expression in mouse mammary gland promotes tumorigenesis. TP53 mutations co-occur with PIK3CA mutations in human breast cancers. We previously generated a conditionally activatable Pik3caH1047R;MMTV-Cre mouse model and found a few malignant sarcomatoid (spindle cell) carcinomas that had acquired spontaneous dominant-negative Trp53 mutations. METHODS: A Pik3caH1047R;Trp53R270H;MMTV-Cre double mutant mouse breast cancer model was generated. Tumors were characterized by histology, marker analysis, transcriptional profiling, single-cell RNA-seq, and bioinformatics. Cell lines were developed from mutant tumors and used to identify and confirm genes involved in metastasis. RESULTS: We found Pik3caH1047R and Trp53R270H cooperate in driving oncogenesis in mammary glands leading to a shorter latency than either alone. Double mutant mice develop multiple histologically distinct mammary tumors, including adenocarcinoma and sarcomatoid (spindle cell) carcinoma. We found some tumors to be invasive and a few metastasized to the lung and/or the lymph node. Single-cell RNA-seq analysis of the tumors identified epithelial, stromal, myeloid, and T cell groups. Expression analysis of the metastatic tumors identified S100a4 as a top candidate gene associated with metastasis. Metastatic tumors contained a much higher percentage of epithelial-mesenchymal transition (EMT)-signature positive and S100a4-expressing cells. CRISPR/CAS9-mediated knockout of S100a4 in a metastatic tumor-derived cell line disrupted its metastatic potential indicating a role for S100a4 in metastasis. CONCLUSIONS: Pik3caH1047R;Trp53R270H;MMTV-Cre mouse provides a preclinical model to mimic a subtype of human breast cancers that carry both PIK3CA and TP53 mutations. It also allows for understanding the cooperation between the two mutant genes in tumorigenesis. Our model also provides a system to study metastasis and develop therapeutic strategies for PIK3CA/TP53 double-positive cancers. S100a4 found involved in metastasis in this model can be a potential diagnostic and therapeutic target.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias Mamárias Experimentais/etiologia , Neoplasias Mamárias Experimentais/metabolismo , Vírus do Tumor Mamário do Camundongo , Mutação , Proteína A4 de Ligação a Cálcio da Família S100/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Infecções Tumorais por Vírus/complicações , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Transformação Celular Viral , Classe I de Fosfatidilinositol 3-Quinases/genética , Modelos Animais de Doenças , Feminino , Marcação de Genes , Humanos , Neoplasias Mamárias Experimentais/patologia , Camundongos , Proteína Supressora de Tumor p53/genética , Infecções Tumorais por Vírus/virologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Int J Mol Sci ; 21(1)2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31877944

RESUMO

HPV-DNA integration results in dysregulation of viral oncogene expression. Because viral-cellular fusion transcripts inherently lack the viral AU-rich elements of the 3'UTR, they are considered to be more stable than episome-derived transcripts. The aim of this study is to provide formal proof for this assumption by comparing the stability of viral early transcripts derived from episomal and integrated HPV16 DNA, respectively. Full-length cDNA of three fusion transcripts comprising viral and cellular sequences in sense orientation were amplified and cloned into the adeno-viral-vector pAd/CMV/V5-DEST. The most abundant HPV16 oncogene transcript E6*I-E7-E1vE4-E5 with and without 3'UTR, served as reference and control, respectively. Human primary keratinocytes were transduced using high titer virus stocks. qRT-PCR was performed to determine mRNA stability in relation to GAPDH in the presence of actinomycin-D. In four independent transduction experiments, all three viral-cellular fusion transcripts were significantly more stable compared to the episome-derived reference. Among the three viral-cellular fusion transcripts the most stable transcript was devoid of the instability core motif "AUUUA". Unexpectedly, there was no significant difference in the stability between the episome-derived transcripts either with or without 3'UTR, indicating that the AU-rich elements of the 3'UTR are not contributing to RNA stability. Instead, the three "AUUUA" motifs located in the untranslated region between the viral E4 and E5 genes may be responsible for the instability. This is the first report showing that authentic viral-cellular fusion transcripts are more stable than episome-derived transcripts. The longer half-life of the fusion transcripts may result in increased levels of viral oncoproteins and thereby drive the carcinogenic process.


Assuntos
Transformação Celular Viral , Queratinócitos/metabolismo , Proteínas Oncogênicas Virais/biossíntese , Estabilidade de RNA , RNA Viral/metabolismo , Proteínas Repressoras/biossíntese , Neoplasias do Colo do Útero/metabolismo , Adenoviridae , Fusão Celular , Feminino , Vetores Genéticos , Humanos , Queratinócitos/patologia , Proteínas Oncogênicas Virais/genética , RNA Viral/genética , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
13.
PLoS Pathog ; 15(12): e1008228, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841561

RESUMO

Epstein-Barr virus (EBV) is an oncogenic herpesvirus and WHO class 1 carcinogen that resides in B lymphocytes of nearly all humans. While silent in most, EBV can cause endemic Burkitt lymphoma in children and post-transplant lymphoproliferative disorders/lymphomas in immunocompromised hosts. The pathogenesis of such lymphomas is multifactorial but to a large extent depends on EBV's ability to aggressively drive cellular DNA replication and B cell proliferation despite cell-intrinsic barriers to replication. One such barrier is oncogenic replication stress which hinders the progression of DNA replication forks. To understand how EBV successfully overcomes replication stress, we examined cellular replication forks in EBV-transformed B cells using iPOND (isolation of Proteins on Nascent DNA)-mass spectrometry and identified several cellular proteins that had not previously been linked to DNA replication. Of eight candidate replisome-associated proteins that we validated at forks in EBV-transformed cells and Burkitt lymphoma-derived cells, three zinc finger proteins (ZFPs) were upregulated early in B cells newly-infected with EBV in culture as well as expressed at high levels in EBV-infected B blasts in the blood of immunocompromised transplant recipients. Expressed highly in S- and G2-phase cells, knockdown of each ZFP resulted in stalling of proliferating cells in the S-phase, cleavage of caspase 3, and cell death. These proteins, newly-identified at replication forks of EBV-transformed and Burkitt lymphoma cells therefore contribute to cell survival and cell cycle progression, and represent novel targets for intervention of EBV-lymphomas while simultaneously offering a window into how the replication machinery may be similarly modified in other cancers.


Assuntos
Linfócitos B/virologia , Transformação Celular Viral/fisiologia , Infecções por Vírus Epstein-Barr/metabolismo , Origem de Replicação/fisiologia , Dedos de Zinco/fisiologia , Linfócitos B/patologia , Linfoma de Burkitt/virologia , Proliferação de Células/fisiologia , Herpesvirus Humano 4 , Humanos
14.
Papillomavirus Res ; 8: 100188, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31629093

RESUMO

BACKGROUND: Human Papillomavirus (HPV) infection is well established in oropharyngeal squamous cell carcinoma (OPSCC) and cervical cancer (CC). However, the association between both HPV related cancers remains unclear. The purpose of this study was to investigate the association between HPV related cancers of the oropharynx and cervix. METHODS: A provincial cancer registry was used to retrospectively identify all patients diagnosed with OPSCC from 1997-2015. The standardized incidence ratio (SIR) of CC history in women with p16+/-OPSCC was measured. RESULTS: From 372 women with OPSCC included, the SIR of CC was significantly higher across all ages compared to the general population in Alberta, Canada (p < 0.0001). CONCLUSIONS: Women with HPV/p16+ OPSCC have a significantly higher risk of CC compared to the general population.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/etiologia , Neoplasias Orofaríngeas/epidemiologia , Neoplasias Orofaríngeas/etiologia , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/etiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Alberta/epidemiologia , Carcinoma de Células Escamosas/diagnóstico , Transformação Celular Viral , Suscetibilidade a Doenças , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/diagnóstico , Papillomaviridae/classificação , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Vigilância da População , Neoplasias do Colo do Útero/diagnóstico , Adulto Jovem
15.
Int J Mol Sci ; 20(19)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575080

RESUMO

Melanocytes (MCs) are specialized cells that synthesize melanin within the melanosome. Cultured MCs are useful in order to study their role in relation to pigmentation. However, MC isolation is laborious and the obtained cells have a limited culture time. In this study, we transformed lentivirus-mediated simian virus 40 Large T (SV40-LT) into primary rabbit melanocytes (Pri RMCs) to establish an immortalized cell line. Morphologically, the immortalized RMCs (Im RMC) were indistinguishable from the Pri RMCs, and dendrites were visible following Dopa staining. No significant differences in cell proliferation or growth between immortalized and primary RMCs were observed. Based on melanocyte-specific markers, the expression of MITF, TYR, and TYRP1 were detected by PCR, immunofluorescence staining, and western blot analysis. Through karyotype, soft agar, and tumorigenesis assays, the immortalized RMCs did not undergo malignant transformation. Our results show that Im RMCs can be used as a tool cell for future MC studies on the pigmentation mechanisms of fur animals.


Assuntos
Antígenos Virais de Tumores/genética , Transformação Celular Viral , Melanócitos/metabolismo , Melanócitos/patologia , Vírus 40 dos Símios/genética , Animais , Linhagem Celular Transformada , Proliferação de Células , Xenoenxertos , Humanos , Imuno-Histoquímica , Cariótipo , Camundongos , Coelhos , Transdução Genética
16.
Int J Mol Sci ; 20(19)2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31569614

RESUMO

Head and neck squamous cell carcinomas (HNSCCs) contribute to over 300,000 deaths every year worldwide. Although the survival rates have improved in some groups of patients, mostly due to new treatment options and the increasing percentage of human papillomavirus (HPV)-related cancers, local recurrences and second primary tumors remain a great challenge for the clinicians. Presently, there is no biomarker for patient surveillance that could help identify patients with HNSCC that are more likely to experience a relapse or early progression, potentially requiring closer follow-up or salvage treatment. MicoRNAs (miRNAs) are non-coding RNA molecules that posttranscriptionally modulate gene expression. They are highly stable and their level can be measured in biofluids including serum, plasma, and saliva, enabling quick results and allowing for repeated analysis during and after the completion of therapy. This has cemented the role of miRNAs as biomarkers with a huge potential in oncology. Since altered miRNA expression was described in HNSCC and many miRNAs play a role in radio- and chemotherapy resistance, cancer progression, and metastasis, they can be utilized as biomarkers of these phenomena. This review outlines recent discoveries in the field of extracellular miRNA-based biomarkers of HNSCC progression and metastasis, with a special focus on HPV-related cancers and radioresistance.


Assuntos
Biomarcadores Tumorais , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , MicroRNAs/genética , Animais , Transformação Celular Viral/genética , Terapia Combinada , Progressão da Doença , Espaço Extracelular , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Imunoterapia , Metástase Neoplásica , Estadiamento de Neoplasias , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/virologia , Radioterapia , Resultado do Tratamento
17.
Proc Natl Acad Sci U S A ; 116(40): 20104-20114, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31527246

RESUMO

Viral cancers show oncogene addiction to viral oncoproteins, which are required for survival and proliferation of the dedifferentiated cancer cell. Human Merkel cell carcinomas (MCCs) that harbor a clonally integrated Merkel cell polyomavirus (MCV) genome have low mutation burden and require viral T antigen expression for tumor growth. Here, we showed that MCV+ MCC cells cocultured with keratinocytes undergo neuron-like differentiation with neurite outgrowth, secretory vesicle accumulation, and the generation of sodium-dependent action potentials, hallmarks of a neuronal cell lineage. Cocultured keratinocytes are essential for induction of the neuronal phenotype. Keratinocyte-conditioned medium was insufficient to induce this phenotype. Single-cell RNA sequencing revealed that T antigen knockdown inhibited cell cycle gene expression and reduced expression of key Merkel cell lineage/MCC marker genes, including HES6, SOX2, ATOH1, and KRT20 Of these, T antigen knockdown directly inhibited Sox2 and Atoh1 expression. MCV large T up-regulated Sox2 through its retinoblastoma protein-inhibition domain, which in turn activated Atoh1 expression. The knockdown of Sox2 in MCV+ MCCs mimicked T antigen knockdown by inducing MCC cell growth arrest and neuron-like differentiation. These results show Sox2-dependent conversion of an undifferentiated, aggressive cancer cell to a differentiated neuron-like phenotype and suggest that the ontology of MCC arises from a neuronal cell precursor.


Assuntos
Antígenos Virais de Tumores/genética , Carcinoma de Célula de Merkel/etiologia , Carcinoma de Célula de Merkel/metabolismo , Poliomavírus das Células de Merkel/genética , Fenótipo , Infecções por Polyomavirus/complicações , Fatores de Transcrição SOXB1/genética , Antígenos Virais de Tumores/imunologia , Antígenos Virais de Tumores/metabolismo , Carcinoma de Célula de Merkel/patologia , Ciclo Celular/genética , Linhagem Celular Tumoral , Linhagem da Célula/genética , Transformação Celular Viral , Técnicas de Silenciamento de Genes , Humanos , Queratinócitos , Células de Merkel/metabolismo , Poliomavírus das Células de Merkel/imunologia , Neuritos/metabolismo , Neurônios/metabolismo , Infecções por Polyomavirus/imunologia , Infecções por Polyomavirus/virologia , Fatores de Transcrição SOXB1/metabolismo , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia
19.
Am J Pathol ; 189(11): 2181-2195, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31449776

RESUMO

Hepatitis B virus (HBV) e antigen (HBeAg) is associated with viral persistence and pathogenesis. Resistance of HBV-infected hepatocytes to apoptosis is seen as one of the primary promotors for HBV chronicity and malignancy. Fas receptor/ligand (Fas/FasL) and the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) system plays a key role in hepatic death during HBV infection. We found that HBeAg mediates resistance of hepatocytes to FasL or TRAIL-induced apoptosis. Introduction of HBeAg into human hepatocytes rendered resistance to FasL or TRAIL cytotoxicity in a p53-dependent manner. HBeAg further inhibited the expression of p53, total Fas, membrane-bound Fas, TNF receptor superfamily member 10a, and TNF receptor superfamily member 10b at both mRNA and protein levels. In contrast, HBeAg enhanced the expression of soluble forms of Fas through facilitation of Fas alternative mRNA splicing. In a mouse model, expression of HBeAg in mice injected with recombinant adenovirus-associated virus 8 inhibited agonistic anti-Fas antibody-induced hepatic apoptosis. Xenograft tumorigenicity assay also found that HBeAg-induced carcinogenesis was resistant to the proapoptotic effect of TRAIL and chemotherapeutic drugs. These results indicate that HBeAg may prevent hepatocytes from FasL and TRAIL-induced apoptosis by regulating the expression of the proapoptotic and antiapoptotic forms of death receptors, which may contribute to the survival and persistence of infected hepatocytes during HBV infection.


Assuntos
Apoptose , Resistencia a Medicamentos Antineoplásicos , Antígenos E da Hepatite B/fisiologia , Hepatócitos/fisiologia , Hepatócitos/virologia , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Transformação Celular Viral/fisiologia , Células Cultivadas , Progressão da Doença , Regulação para Baixo , Células HEK293 , Células Hep G2 , Hepatite B/complicações , Hepatite B/patologia , Vírus da Hepatite B/fisiologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus
20.
Rev Med Virol ; 29(6): e2076, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31407416

RESUMO

Seven oncogenic viruses are known for tumorigenesis and contribute to 12% of all human cancers. The oncogenic factors, the target tissue, and pathology of cancer vary among these viruses with several mechanisms proposed for the initiation and development of cancer. Aneuploidy in cells is associated with anomalies in chromosome number that can be a hallmark of cancer, a disease defined by expanded proliferative potential. In this review, we summarize the different mechanisms of aneuploidy and furthermore discuss recent findings of the role of viral oncoproteins in inducing cellular aneuploidy that might facilitate tumorigenesis. Improved understanding of viral oncogenesis may help to find new strategies for controlling virus-associated cancers.


Assuntos
Aneuploidia , Transformação Celular Viral , Vírus Oncogênicos/fisiologia , Animais , Humanos , Neoplasias/etiologia , Neoplasias/metabolismo , Neoplasias/patologia , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/virologia
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