RESUMO
The papillomavirus life cycle parallels keratinocyte differentiation in stratifying epithelia. We have previously shown that the human papillomavirus type 8 (HPV8) E2 protein downregulates beta4-integrin expression in normal human keratinocytes, which may trigger subsequent differentiation steps. Here, we demonstrate that the DNA binding domain of HPV8 E2 is sufficient to displace a cellular factor from the beta4-integrin promoter. We identified the E2-displaceable factor as activator protein 1 (AP-1), a heteromeric transcription factor with differentiation-specific expression in the epithelium. beta4-Integrin-positive epithelial cells displayed strong AP-1 binding activity. Both AP-1 binding activity and beta4-integrin expression were coregulated during keratinocyte differentiation suggesting the involvement of AP-1 in beta4-integrin expression. In normal human keratinocytes the AP-1 complex was composed of JunB and Fra-1 subunits. Chromatin immunoprecipitation assays confirmed that JunB/Fra-1 proteins interact in vivo with the beta4-integrin promoter and that JunB/Fra-1 promoter occupancy is reduced during keratinocyte differentiation as well as in HPV8 E2 positive keratinocytes. Ectopic expression of the tethered JunB/Fra-1 heterodimer in normal human keratinocytes activated the beta4-integrin promoter, while coexpression of HPV8 E2 reverted the JunB/Fra-1 effect. In summary, we identified a novel mechanism of human beta4-integrin regulation that is specifically targeted by the HPV8 E2 protein mimicking transcriptional conditions of differentiation. This may explain the early steps of how HPV8 commits its host cells to the differentiation process required for the viral life cycle.
Assuntos
Regulação da Expressão Gênica/fisiologia , Integrina beta4/genética , Queratinócitos/virologia , Proteínas Oncogênicas Virais/fisiologia , Proteínas Proto-Oncogênicas c-fos/fisiologia , Proteínas Proto-Oncogênicas c-jun/fisiologia , Transativadores/fisiologia , Sequência de Bases , Linhagem Celular Tumoral , Células Cultivadas , Imunoprecipitação da Cromatina , Primers do DNA , Dimerização , Humanos , Queratinócitos/metabolismo , Regiões Promotoras GenéticasAssuntos
Epidermodisplasia Verruciforme/diagnóstico , Epidermodisplasia Verruciforme/etiologia , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Diagnóstico Diferencial , Epidermodisplasia Verruciforme/virologia , Feminino , Infecções por HIV/virologia , Humanos , Pessoa de Meia-IdadeRESUMO
Human papillomaviruses (HPV) have been implicated in the development of nonmelanoma skin cancer (NMSC). The molecular mechanisms by which these viruses contribute towards NMSC are poorly understood. We have used an in vitro skin-equivalent model generated by transducing primary adult human epidermal keratinocytes with retroviruses expressing HPV genes to investigate the mechanisms of viral transformation. In this model, keratinocytes expressing HPV genes are seeded onto a mesenchyme composed of deepidermalized human dermis that had been repopulated with primary dermal fibroblasts. Expression of the HPV8 E7 gene caused both an enhancement of terminal differentiation and hyperproliferation, but most strikingly, the acquisition of the ability to migrate and invade through the underlying dermis. The basement membrane integrity was disrupted in a time-dependent manner in areas of invading keratinocytes, as evidenced by immunostaining of its protein components collagen types VII, IV, and laminin 5. This was accompanied by the overexpression of extracellular matrix metalloproteinases MMP-1, MMP-8, and MT-1-MMP. These results suggest that the cutaneous HPV type 8 that is frequently found in NMSC of epidermodysplasia verruciformis patients may actively promote an invasive keratinocyte phenotype. These findings also highlight the importance of epithelial-extracellular matrix-mesenchymal interactions that are required to support cell invasion.
Assuntos
Transformação Celular Viral/genética , Queratinócitos/patologia , Queratinócitos/virologia , Proteínas Oncogênicas Virais/genética , Neoplasias Cutâneas/virologia , Pele/patologia , Pele/virologia , Membrana Basal/virologia , Diferenciação Celular/genética , Processos de Crescimento Celular/genética , Humanos , Queratinócitos/enzimologia , Metaloproteinase 1 da Matriz/biossíntese , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 8 da Matriz/biossíntese , Metaloproteinase 8 da Matriz/genética , Metaloproteinases da Matriz Associadas à Membrana , Metaloendopeptidases/biossíntese , Metaloendopeptidases/genética , Papillomaviridae/genética , Retroviridae/genética , Pele/enzimologia , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologia , Transdução GenéticaRESUMO
Epidemiological evidence is accumulating that beta-human papillomaviruses (HPV) synergize with UV-light in the development of precancerous actinic keratosis, and cutaneous squamous cell carcinomas (cSCC), one of the most common cancers in the Caucasian population. We previously demonstrated the tumorigenic activity of beta-HPV type 8 (HPV8) in the skin of transgenic mice and its cooperation with UV-light. Analysis of underlying mechanisms now showed that in keratinocytes expressing the HPV8E6 protein a transient increase of tyrosine phosphorylated epidermal growth factor receptor (EGFR) in response to UV-irradiation occurred, while EGFR tyrosine phosphorylation, i.e., receptor tyrosine kinase (RTK)-activity was hardly affected in empty vector control cells. FACS and immunofluorescences revealed that the EGFR was internalized into early endosomes in response to UV-exposure in both, HPV8E6 positive and in control cells, yet with a higher rate in the presence of HPV8E6. Moreover, only in HPV8E6 expressing keratinocytes the EGFR was further sorted into CD63+ intraluminal vesicles, indicative for trafficking to late endosomes. The latter requires the ubiquitination of the EGFR, and in correlation, we could show that only in HPV8E6 positive keratinocytes the EGFR was ubiquitinated upon UV-exposure. HPV8E6 and tyrosine phosphorylated EGFR directly interacted which was enhanced by UV-irradiation. The treatment of K14-HPV8E6 transgenic mice with Canertinib, an inhibitor of the RTK-activity of the EGFR, suppressed skin papilloma growth in response to UV-irradiation. This confirms the crucial role of the RTK-activity of the EGFR in HPV8E6 and UV-mediated papillomatosis in transgenic mice. Taken together, our results demonstrate that HPV8E6 alters the signaling of the UV-activated EGFR and this is a critical step in papilloma formation in response to UV-light in transgenic mice. Our results provide a molecular basis how a beta-HPV type may support early steps of skin tumor formation in cooperation with UV-light.
RESUMO
BACKGROUND: To analyse the evolution of resistance patterns in patients undergoing treatment interruption (TI) and re-initiating highly active anti-retroviral therapy (HAART). METHODS: HIV-RT and -PR gene-sequences were analysed in 14 patients (>5 failing prior drugs) before and during TI and under a new HAART. Genotypes were interpreted using two bioinformatics systems. Additionally, virus load (VL) and CD4(+)-T-cell counts were measured. RESULTS: Six patients (42%) achieved sustained undetectable VL up to one year after TI (responders), while 8 (57%) maintained VL of more than 2,000 copies/mL (non-responders). Different patterns of resistance-mutations evolution were detected. During TI loss of all mutations was observed in three patients, a reduction of mutations was detected in seven patients, and no alteration was seen in four patients. In the responders, 87.5% of protease inhibitor (PI)-resistance mutations waned during TI and remained undetectable under the new treatment. In contrast, in the non-responder group most PI-resistance mutations continued noticeable under the new therapy. Loss of primary PI-resistance mutations and the presence of one fully active PI in the new regimen significantly correlated with success of subsequent treatment (p=0.028). In two patients new reverse transcriptase associated mutations were detected during TI, G190A (NNRTI mutation) and K70R (NRTI mutation). Appearance of K70R could be explained by a reverse direction of a previously described pathway of thymidin analogues mutation resistance development, while G190A could be due to prolonged subinhibitory drug levels after cessation of NNRTIs. CONCLUSION: In the evolution of HAART-resistance, different patterns were observed in responders and non-responders during but not before TI. Absence of PI-resistance associated mutations during and after TI and administration of a predicted fully active PI for the new therapy correlated with success. Newly detected mutations during TI may indicate reversibility of previously described mutational pathways.
Assuntos
Antirretrovirais/farmacologia , Farmacorresistência Viral/genética , Evolução Molecular , Infecções por HIV/virologia , HIV/efeitos dos fármacos , Antirretrovirais/uso terapêutico , Terapia Antirretroviral de Alta Atividade , HIV/genética , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/farmacologia , Humanos , Mutação , Inibidores de Proteases/farmacologia , DNA Polimerase Dirigida por RNA/genética , Especificidade da Espécie , Resultado do Tratamento , Suspensão de TratamentoRESUMO
A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor.
Assuntos
Betapapillomavirus/fisiologia , Betapapillomavirus/patogenicidade , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/virologia , Carcinogênese , Humanos , Queratinócitos/virologia , Infecções por Papillomavirus/epidemiologia , Neoplasias Cutâneas/epidemiologiaRESUMO
BACKGROUND: Patients with psoriasis treated with psoralen-UV-A (PUVA) are at increased risk of skin cancer; however, the exact causes of this increased incidence are not well understood. It has been suggested that PUVA may increase expression of the tumorigenic agent human papillomavirus (HPV) in skin by directly stimulating virus replication, immune suppression, or both, thereby leading to skin cancer formation. OBJECTIVE: To determine whether HPV DNA prevalence in the skin is increased after long-term PUVA treatment. DESIGN: Screening for the presence of HPV sequences in DNA isolated from plucked body hairs of patients with psoriasis with a history of PUVA exposure and a history of skin cancer (group A), PUVA exposure and no history of skin cancer (group B), and no PUVA exposure and no history of skin cancer (group C). SETTING: University hospital. PATIENTS AND METHODS: Hair samples were obtained from 81 patients with psoriasis (56 men and 25 women; mean age, 52 years), including 16 in group A (mean number of PUVA exposures, 702), 35 in group B (mean number of PUVA exposures, 282), and 30 in group C. DNA was isolated from the hair samples and analyzed by polymerase chain reaction with the use of 2 nested primer systems specific for epidermodysplasia verruciformis-associated or related and genital or mucosal virus types, respectively. RESULTS: The rate of HPV DNA positivity was significantly higher in groups A (73% [11/15]) and B (69% [24/35]) than in group C (36% [10/28]) (A + B vs C, P =.009; chi(2) test; age adjusted). Conclusion The prevalence of HPV in the skin (hair follicles) is increased in patients with psoriasis who have a history of PUVA exposure.
Assuntos
Cabelo/virologia , Terapia PUVA/efeitos adversos , Papillomaviridae/isolamento & purificação , Psoríase/epidemiologia , Psoríase/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Estudos de Casos e Controles , DNA Viral/análise , Feminino , Ficusina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Papillomaviridae/classificação , Papillomaviridae/genética , Fármacos Fotossensibilizantes/administração & dosagem , Prevalência , Psoríase/tratamento farmacológicoRESUMO
OBJECTIVE: The aim of our study was to evaluate human papillomavirus (HPV) infection as a risk factor for cutaneous squamous cell carcinoma (SCC) in immunocompetent individuals. DESIGN: Hospital-based case-control study. SETTING: Referral center for dermatologic diseases for central and southern Italy. PARTICIPANTS: Consecutive patients with histologically confirmed cutaneous SCC (n = 46) and control subjects (n = 84) chosen by frequency matching (age and sex) among patients admitted with unrelated diseases. MAIN OUTCOME MEASURE: Infection with epidermodysplasia verruciformis-related HPV types, blindly assessed by serologic testing (viruslike particle enzyme-linked immunosorbent assay). Information was obtained on known potentially confounding risk factors (family history, history and signs of sun exposure, and pigmentary traits) and on history of HPV-related lesions and diseases, assessed by interview and examination by a dermatologist. RESULTS: Positive serologic findings for HPV type 8 were associated with SCC (odds ratio, 3.2; 95% confidence interval, 1.3-7.9) independently of other risk factors, whereas positive serologic findings for HPV type 15 were negatively associated with SCC (odds ratio, 0.4; 95% confidence interval, 0.2-0.9). Other variables significantly associated with the tumor were family history of skin cancer, professional or recreational sun exposure, light eye color, high number of solar keratoses and seborrheic keratoses on the body surface, and residency in radon-emitting buildings. CONCLUSIONS: Positive serologic findings for HPV type 8 are associated with SCC occurrence in immunocompetent individuals. Viral infection could act as a cofactor in the tumor development, along with genetic predisposition, solar radiation, and other environmental exposures. If confirmed, these findings could open new perspectives for treatment and prevention of SCC.
Assuntos
Carcinoma de Células Escamosas/virologia , Imunocompetência , Papillomaviridae , Infecções por Papillomavirus/complicações , Neoplasias Cutâneas/virologia , Infecções Tumorais por Vírus/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Proteínas do Capsídeo/imunologia , Carcinoma de Células Escamosas/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Papillomaviridae/imunologia , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/imunologia , Fatores de Risco , Neoplasias Cutâneas/imunologia , Infecções Tumorais por Vírus/diagnóstico , Infecções Tumorais por Vírus/imunologiaRESUMO
The aim of the present study was to characterise natural cell-mediated cytotoxicity against COS-7 cells transfected with potentially oncogenic HPV-8 L1 DNA sequences cloned in sense and antisense orientation and to evaluate their lysis by peripheral blood lymphocytes (PBL) from patients with epidermodysplasia verruciformis (EV), a rare disease associated with life-long infection by specific HPV types. COS-7 cells were transfected with HPV-8 Hinc II restriction fragment (nucleotide positions 5434-7654) cloned in sense (COS-L1S) and antisense (COS-L1A) orientation into pCB6 expression vector. Cytotoxic activity of isolated PBL against COS cell lines as well as K562 erythroleukaemic cells was evaluated by 51Cr-release assay. We found that lymphocytes responsible for natural lysis of COS and K562 cells are CD3-negative CD56-positive natural killer (NK) cells. Analysis of NK cell cytotoxic activity against different COS cell lines has revealed that lymphocytes from healthy subjects killed COS-L1S cells significantly more efficiently than wild COS-7 and COS-L1A cells. Significantly more efficient lysis of COS-L1S cells was also observed in EV patients. Thus, expression of HPV L1 renders target cells more susceptible to NK-mediated cytotoxicity that may enable more effective elimination of transformed cells.
Assuntos
Epidermodisplasia Verruciforme/virologia , Proteínas Oncogênicas Virais/genética , Papillomaviridae/metabolismo , Linfócitos T Citotóxicos/metabolismo , Adulto , Animais , Células COS , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/metabolismo , TransfecçãoRESUMO
The antioxidant enzyme peroxiredoxin 6 (Prdx6) is a key regulator of the cellular redox balance, particularly under stress conditions. We identified Prdx6 as an important player in different phases of skin carcinogenesis. Loss of Prdx6 in mice enhanced the susceptibility to skin tumorigenesis, whereas overexpression of Prdx6 in keratinocytes of transgenic mice had the opposite effect. The tumor-preventive effect of Prdx6, which was observed in a human papilloma virus 8-induced and a chemically induced tumor model, was not due to alterations in keratinocyte proliferation, apoptosis, or in the inflammatory response. Rather, endogenous and overexpressed Prdx6 reduced oxidative stress as reflected by the lower levels of oxidized phospholipids in the protumorigenic skin of Prdx6 transgenic mice and the higher levels in Prdx6-knockout mice than in control animals. In contrast to its beneficial effect in tumor prevention, overexpression of Prdx6 led to an acceleration of malignant progression of existing tumors, revealing a dual function of this enzyme in the pathogenesis of skin cancer. Finally, we found strong expression of PRDX6 in keratinocytes of normal human skin and in the tumor cells of squamous cell carcinomas, indicating a role of Prdx6 in human skin carcinogenesis. Taken together, our data point to the potential usefulness of Prdx6 activators or inhibitors for controlling different stages of skin carcinogenesis.
Assuntos
Antioxidantes/metabolismo , Peroxirredoxina VI/metabolismo , Neoplasias Cutâneas/enzimologia , 9,10-Dimetil-1,2-benzantraceno , Adulto , Animais , Carcinogênese/metabolismo , Feminino , Genes Supressores de Tumor , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Camundongos Transgênicos , Peroxirredoxina VI/deficiência , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologiaRESUMO
Organ transplant recipients (OTR) are at increased risk of cutaneous squamous cell carcinoma, which may be related to reactivation of human papillomavirus (HPV) infections. Measurement of change in HPV antibodies after transplantation would help to explore this hypothesis. We measured antibodies to 34 HPV types on up to six occasions over 18 months in 441 OTRs from five European countries. At baseline (mean 24 days after transplantation), 80% of all OTRs were seropositive to at least one HPV type. The beta HPV genus had the highest seroprevalence (45%). For most HPV genera baseline seroprevalence peaked between 40 and 59 years old. Most OTRs retained their serostatus over time and antibody levels were stable. Seroprevalence in immunosuppressed OTRs is stable in the 18 months immediately after transplantation. Thus there is no short-term evidence that immunosuppression leads to new or reactivated skin infection with HPV sufficient to induce antibodies.
Assuntos
Anticorpos Antivirais/sangue , Papillomaviridae/imunologia , Infecções por Papillomavirus/epidemiologia , Transplantes/virologia , Adulto , Carcinoma de Células Escamosas/virologia , Europa (Continente)/epidemiologia , Feminino , Humanos , Terapia de Imunossupressão , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Papillomaviridae/classificação , Papillomaviridae/genética , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Fatores de Risco , Estudos Soroepidemiológicos , Neoplasias Cutâneas/virologia , Transplantes/efeitos adversosRESUMO
DNA tumorviruses like adenoviruses (AdV) or human papillomaviruses (HPV) have adopted various strategies to interfere with antiproliferative transforming growth factor-beta (TGF-beta) signalling. Here we report that the AdV E1A oncoprotein is sufficient to induce Smad7 expression, an inhibitor of TGF-beta signalling. E1A but not HPV oncoproteins activated the Smad7 promoter. A promoter proximal E-box was crucial for E1A-mediated transcriptional activity. E1A but not HPV oncoproteins induced specific binding activity at this E-box, which was identified as upstream stimulatory factor. In conclusion, these results unravel a novel mechanism of how the AdV E1A oncoprotein induces a cellular inhibitor of TGF-beta signalling.
Assuntos
Proteínas E1A de Adenovirus/metabolismo , Transformação Celular Viral/fisiologia , Elementos E-Box/genética , Regiões Promotoras Genéticas/genética , Proteína Smad7/genética , Linhagem Celular Tumoral , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , Papillomaviridae , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/fisiologia , Proteína Smad7/metabolismo , Transfecção , Fator de Crescimento Transformador beta/metabolismoRESUMO
BACKGROUND AND OBJECTIVES: Minority HIV-1 populations with resistance mutations might result in therapy failure. The prevalence of transmitted minorities in therapy-naïve patients and their influence on the virological outcome of the first-line-therapy need clarification. STUDY DESIGN: The HIV reverse transcriptase (RT) of 159 therapy-naïve patients from the RESINA-cohort was genotyped. The relative amount of RT-K103N was measured by primer specific PCR. The response to first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-therapy was evaluated. RESULTS: Bulk-sequencing detected 1 NNRTI mutation (no K103N) in six patients (1.26%). K103N minorities were found in 20.1% of the samples, more frequently in HIV-1 non-B subtypes (40.6%) than in subtype B (15.0%) (p=0.0025). NNRTI treatment failed after 12 weeks in 24% of 17 patients with minority, but only in 15% of 67 patients without minority. CONCLUSIONS: K103N minorities were found in 20.1% of the patients, whereas the prevalence of major K103N populations was 3% in the total RESINA-cohort. K103N minorities were more frequent in non-B subtypes. There is some evidence for a higher risk of NNRTI-treatment failure in patients with K103N minorities; however, the majority of patients with minority underwent a successful first-line-treatment.
Assuntos
Infecções por HIV/virologia , Transcriptase Reversa do HIV/genética , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação , Adulto , Idoso , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Estudos de Coortes , Interpretação Estatística de Dados , Feminino , Genes pol , Genótipo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-1/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , RNA Viral/análise , Inibidores da Transcriptase Reversa/farmacologia , Inibidores da Transcriptase Reversa/uso terapêutico , Falha de TratamentoRESUMO
Betapapillomavirus (betaPV) infections are often associated with squamous-cell carcinoma (SCC) and the prevalence of betaPV infections in (immunosuppressed) SCC patients is known to be high. The distribution and possible associated factors of betaPV infections in the general population, however, are largely unknown. To address this issue, betaPV infection was studied in 1405 SCC-free immunocompetent (n=845) and immunosuppressed (n=560) individuals from six countries of different latitudes. A standard study protocol was used to obtain information about age, sex, UV-irradiation and skin type, and from all participants eyebrow hairs were collected for detection and genotyping of 25 established betaPV types using the PM-PCR reverse hybridization assay (RHA) method. The frequency of betaPV-positive participants ranged from 84 to 91% in the immunocompetent population with HPV23 as the most prevalent type, and from 81 to 98% in the immunosuppressed population with HPV23 as the most or the second most prevalent type. The median number of infecting betaPV types ranged from four to six in the immunocompetent and from three to six in the immunosuppressed population. Increasing age in the immunocompetent participants and (duration of) immunosuppression in the immunosuppressed patients were associated with betaPV infection. In both groups, sex, skin phototype, sunburns and sun-exposure were not consistently associated with betaPV infection. This study demonstrates that betaPV infections are also highly prevalent in SCC-free individuals, with similar HPV types prevailing in both immunocompetent and immunosuppressed persons. Age and (duration of) immunosuppression were identified as betaPV infection-associated factors, whereas characteristics related to sun exposure and skin type were not.
Assuntos
Betapapillomavirus/isolamento & purificação , Carcinoma de Células Escamosas/virologia , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Fatores de Risco , Neoplasias Cutâneas/virologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Betapapillomavirus/classificação , Betapapillomavirus/genética , DNA Viral/genética , Feminino , Genótipo , Humanos , Hospedeiro Imunocomprometido , Terapia de Imunossupressão/efeitos adversos , Masculino , Pessoa de Meia-Idade , Hibridização de Ácido Nucleico/métodos , Prevalência , Adulto JovemRESUMO
Molecular prognostic indicators for oropharyngeal squamous cell carcinoma (OSCC), including HPV-DNA detection, epidermal growth factor receptor (EGFR) and p16 expression, have been suggested in the literature, but none of these are currently used in clinical practice. To compare these predictors, 106 newly diagnosed OSCC for the presence of HPV-DNA and expression of p16 and EGFR were analyzed. The 5-year disease-free survival (DFS) and overall survival (OS) were calculated in relation to these markers and a multivariate Cox analysis was performed. Twenty-eight percent of the cases contained oncogenic HPV-DNA and 30% were positive for p16. The p16 expression was highly correlated with the presence of HPV-DNA (p < 0.001). Univariate analysis of the 5-year DFS revealed a significantly better outcome for patients with p16-positive tumors (84% vs. 49%, p = 0.009). EGFR-negative tumors showed a tendency toward a better prognosis in DFS (74% vs. 47%, p = 0.084) and OS (70% vs. 45%, p = 0.100). Remarkable and highly significant was the combination of p16 and EGFR expression status, leading to 5-year DFS of 93% for p16+/EGFR- tumors vs. 39% for p16-/EGFR+ tumors (p = 0.003) and to a 5-year OS of 79% vs. 38%, respectively (p = 0.010). In multivariate analysis p16 remained a highly significant prognostic marker for DFS (p = 0.030) showing a 7.5-fold increased risk for relapse in patients with p16-negative tumors. Our data indicate that p16 expression is the most reliable prognostic marker for OSCC and further might be a surrogate marker for HPV-positive OSCC. HPV+/p16+ tumors tended to have decreased EGFR expression, but using both immunohistological markers has significant prognostic implications.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , DNA Viral/genética , Receptores ErbB/metabolismo , Neoplasias Orofaríngeas/genética , Neoplasias Orofaríngeas/metabolismo , Papillomaviridae/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/virologia , DNA Viral/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/virologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Probabilidade , Prognóstico , Estudos RetrospectivosRESUMO
Matrix metalloproteinases (MMPs) degrade extracellular matrix. They are involved in cellular proliferation, migration, angiogenesis, invasion and metastasis. MT-1 MMP, a membrane-bound MMP, is expressed in carcinomas of the uterine cervix in vivo. This type of cancer is associated with human papillomavirus (HPV) infection. Here it was shown that keratinocytes transformed with HPV16 or HPV18 in vitro, and HPV-positive cervical carcinoma cell lines, constitutively expressed MT-1 MMP. Expression of the E7 protein from the mucosal and cutaneous high-risk types HPV16 and HPV8, but not from the cutaneous low-risk type HPV1, was sufficient to induce MT-1 MMP expression in primary human keratinocytes and HaCaT cells. As a consequence, MMP-2 was activated. MT-1 MMP expression might play a role in the HPV life cycle by promoting proliferation of host cells and might contribute to their invasive phenotype during malignant progression.
Assuntos
Regulação Enzimológica da Expressão Gênica , Queratinócitos/virologia , Metaloendopeptidases/biossíntese , Proteínas Oncogênicas Virais/fisiologia , Papillomaviridae/fisiologia , Linhagem Celular Tumoral , Transformação Celular Viral , Células Cultivadas , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinases da Matriz Associadas à Membrana , Proteínas E7 de PapillomavirusRESUMO
Our recent analysis of papillomavirus (HPV) DNA in different malignant head and neck tumors revealed that HPV infections occurred most frequently in tonsillar carcinomas (58%) and that 84% of positive cases contained the highly oncogenic HPV type 16. We could also present data in favor of the hypothesis that in view of their clinical behavior and the involved risk factors HPV-positive and HPV-negative tonsillar carcinomas may represent two separate tumor entities. Looking for a surrogate marker, which in further epidemiological studies could replace the laborious and expensive HPV detection/typing we analyzed p16 protein expression in 34 tonsillar carcinomas for their correlation with HPV status. p16 is an inhibitor of cyclin-dependent kinases 4 and 6 which activate the negative cell cycle regulator protein pRB which in turn downregulates p16 expression. It could be shown that in neoplastic cells of the cervix uteri E7 protein of the high-risk HPVs can interfere with this regulatory circuit by its virtue to inactivate pRB and thus lead to the overexpession of p16. We found 53% of the tested tonsillar carcinomas to be HPV positive. 56% of all tumors tested were immunohistochemically positive for the p16 protein. In 16 of 18 of the HPV-positive carcinomas diffuse p16 expression was observed. In contrast, only 1 of the HPV-negative carcinomas showed focal p16 staining (p < 0.001). Clinical outcome analysis revealed a significant correlation of p16 expression with increased disease-free survival (p = 0.02). These data indicate that p16 is a technically simple immunohistological marker, applicable for routine pathological histology, and its prognostic value for survival is fully equivalent to HPV DNA detection.
Assuntos
Carcinoma de Células Escamosas/virologia , Transformação Celular Neoplásica/patologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Neoplasias Tonsilares/virologia , Biomarcadores Tumorais/análise , Biópsia por Agulha , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Inibidor p16 de Quinase Dependente de Ciclina/genética , DNA Viral/análise , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/mortalidade , Probabilidade , Prognóstico , Valores de Referência , Estudos de Amostragem , Sensibilidade e Especificidade , Análise de Sobrevida , Neoplasias Tonsilares/genética , Neoplasias Tonsilares/mortalidadeRESUMO
As representatives of low and high incidence countries respectively, 72 esophageal squamous cell carcinomas and 40 adenocarcinomas from Germany, and 43 esophageal squamous cell carcinomas from Russia were tested for the presence of Epstein-Barr virus (EBV) DNA by PCR and in situ hybridization. Thirty-four percent of the squamous cell carcinomas (SCC) and 26% of the adenocarcinomas (AC) contained EBV DNA as detected by nested PCR. Quantitative analysis using real time PCR revealed one copy of the EBV genome per every 27-200,000 cells. EBER RNA in situ hybridization showed no EBV-specific transcripts in the nuclei of the tumor cells. However, EBER transcripts were expressed in the nuclei of tumor infiltrating lymphocytes in 7 SCC and 1 AC of 24 EBV DNA positive cases. The present data provide no evidence for the persistence of EBV in the tumor cells of esophageal cancer. In contrast to a previous report from Taiwan, EBV is unlikely to play a role in esophageal carcinogenesis.
Assuntos
Adenocarcinoma/imunologia , Adenocarcinoma/virologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/virologia , Infecções por Vírus Epstein-Barr/complicações , Neoplasias Esofágicas/virologia , Herpesvirus Humano 4/isolamento & purificação , Linfócitos/virologia , Núcleo Celular/metabolismo , DNA Viral/genética , Alemanha , Herpesvirus Humano 4/genética , Humanos , Hibridização In Situ , Linfócitos/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Federação RussaRESUMO
Cervical carcinoma cells producing high levels of interleukin-6 (IL-6) were shown to be unresponsive to the cytokine IL-6 due to the loss of their IL-6 receptor. Addition of IL-6 receptor in a soluble form restores IL-6 signalling in SW756 carcinoma cells. This leads to a rapid and strong activation of the transcription factor signal transducer and activator of transcription 3 (STAT3). Nuclear factor IL-6 (NF-IL6, C/EBPbeta) was induced only as a late event. While C/EBPbeta significantly repressed the human papillomavirus type 18 long control region (HPV18-LCR), IL-6 signalling unexpectedly activated the HPV18-LCR in these cells. This IL-6 receptor-mediated induction could be completely reverted by transfection of a dominant-negative STAT3 but not STAT1 expression construct, indicating that STAT3 might play an important role in HPV18 oncogene promoter activation.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Papillomaviridae/genética , Receptores de Interleucina-6/fisiologia , Transativadores/fisiologia , Neoplasias do Colo do Útero/virologia , Proteína beta Intensificadora de Ligação a CCAAT/fisiologia , Feminino , Humanos , Interleucina-6/fisiologia , Regiões Promotoras Genéticas , Fator de Transcrição STAT3 , Células Tumorais CultivadasRESUMO
The papillomavirus life cycle is closely linked to the differentiation program of the host keratinocyte. Thus, late gene expression and viral maturation are restricted to terminally differentiated keratinocytes. A variety of cellular transcription factors including those of the C/EBP family are involved in the regulation of keratinocyte differentiation. In this study we show that the papillomavirus transcription factor E2 cooperates with C/EBPalpha and -beta in transcriptional activation. This synergism was independent of an E2 binding site. E2 and C/EBP factors synergistically transactivated a synthetic promoter construct containing classical C/EBPbeta sites and the C/EBPalpha-responsive proximal promoter of the involucrin gene, which is naturally expressed in differentiating keratinocytes. C/EBPalpha or -beta coprecipitated with E2 proteins derived from human papillomavirus type 8 (HPV8), HPV16, HPV18, and bovine papillomavirus type 1 in vitro and in vivo, indicating complex formation by the cellular and viral factors. The interaction domains could be mapped to the C terminus of E2 and amino acids 261 to 302 located within the bZIP motif of C/EBPbeta. Our data suggest that E2, via its interaction with C/EBP factors, may contribute to enhancing keratinocyte differentiation, which is suppressed by the viral oncoproteins E6 and E7 in HPV-induced lesions.