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1.
Curr Oncol ; 31(4): 1739-1751, 2024 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668035

RESUMO

This study aims to evaluate the clinical outcome of stereotactic radiosurgery as the sole treatment for brain metastases and to assess prognostic factors influencing survival. A total of 108 consecutive patients with 213 metastases were retrospectively analyzed. Treatment was determined with close-meshed MRI follow-up. Various prognostic factors were assessed, and several prognostic indices were compared regarding their reliability to estimate overall survival. Median overall survival was 15 months; one-year overall survival was 50.5%. Both one- and two-year local controls were 90.9%. The rate of new metastases after SRS was 49.1%. Multivariate analysis of prognostic factors revealed that the presence of extracranial metastases, male sex, lower KPI, and progressive extracranial disease were significant risk factors for decreased survival. Of all evaluated prognostic indices, the Basic Score for Brain Metastases (BSBMs) showed the best correlation with overall survival. A substantial survival advantage was found for female patients after SRS when compared to male patients (18 versus 9 months, p = 0.003). SRS of brain metastasis is a safe and effective treatment option when frequent monitoring for new metastases with MRI is performed. Common prognostic scores lack reliable estimation of survival times. Female sex should be considered as an additional independent positive prognostic factor influencing survival.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Humanos , Radiocirurgia/métodos , Masculino , Feminino , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/mortalidade , Pessoa de Meia-Idade , Prognóstico , Idoso , Adulto , Estudos Retrospectivos , Resultado do Tratamento , Idoso de 80 Anos ou mais , Imageamento por Ressonância Magnética/métodos
2.
Eur Urol ; 85(2): 164-170, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37355358

RESUMO

BACKGROUND: The European Association of Urology (EAU) has proposed a risk stratification for patients harboring biochemical recurrence (BCR) after radical prostatectomy (RP). OBJECTIVE: To assess whether this risk stratification helps in choosing patients for salvage radiotherapy (SRT). DESIGN, SETTING, AND PARTICIPANTS: Analyses of 2379 patients who developed BCR after RP (1989-2020), within ten European high-volume centers, were conducted. Early and late SRT were defined as SRT delivered at prostate-specific antigen values <0.5 and ≥0.5 ng/ml, respectively. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable Cox models tested the effect of SRT versus no SRT on death and cancer-specific death. The Simon-Makuch method tested for survival differences within each risk group. RESULTS AND LIMITATIONS: Overall, 805 and 1574 patients were classified as having EAU low- and high-risk BCR. The median follow-up was 54 mo after BCR for survivors. For low-risk BCR, 12-yr overall survival was 87% versus 78% (p = 0.2) and cancer-specific survival was 100% versus 96% (p = 0.2) for early versus no SRT. For high-risk BCR, 12-yr overall survival was 81% versus 66% (p < 0.001) and cancer-specific survival was 98% versus 82% (p < 0.001) for early versus no SRT. In multivariable analyses, early SRT decreased the risk for death (hazard ratio [HR]: 0.55, p < 0.01) and cancer-specific death (HR: 0.08, p < 0.001). Late SRT was a predictor of cancer-specific death (HR: 0.17, p < 0.01) but not death (p = 0.1). CONCLUSIONS: Improved survival was recorded within the high-risk BCR group for patients treated with early SRT compared with those under observation. Our results suggest recommending early SRT for high-risk BCR men. Conversely, surveillance might be suitable for low-risk BCR, since only nine patients with low-risk BCR died from prostate cancer during follow-up. PATIENT SUMMARY: The impact of salvage radiotherapy (SRT) on cancer-specific outcomes stratified according to the European Association of Urology biochemical recurrence (BCR) risk classification was assessed. While men with high-risk BCR should be offered SRT, surveillance might be a suitable option for those with low-risk BCR.


Assuntos
Neoplasias da Próstata , Urologia , Masculino , Humanos , Estadiamento de Neoplasias , Estudos Retrospectivos , Antígeno Prostático Específico/análise , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Prostatectomia/efeitos adversos , Terapia de Salvação/métodos , Recidiva Local de Neoplasia/patologia
3.
Curr Oncol ; 28(6): 4776-4785, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34898552

RESUMO

The COVID-19 pandemic has an unprecedented impact on cancer treatment worldwide. We aimed to evaluate the effects of the pandemic on the radiation treatment of patients in order to provide data for future management of such crises. We compared the number of performed radiotherapy sessions of the pandemic period from February 2020 until May 2021 with those of 2018 and 2019 for reference. At our department, no referred patients had to be rejected or postponed, nor any significant changes in fractionation schedules implemented. Nevertheless, there was a substantial drop in overall radiotherapy sessions in 2020 following the first incidence wave of up to -25% (in June) in comparison to previous years. For breast cancer, a maximum decline of sessions of -45% (July) was recorded. Only a short drop of prostate cancer sessions (max -35%, May) followed by a rebound (+42%, July) was observed. Over the investigated period, a loss of 4.4% of expected patients never recovered. The severe impact of COVID-19 on cancer treatment, likely caused by retarded diagnosis and delayed interdisciplinary co-treatment, is reflected in a lower count of radiotherapy sessions. Radiation oncology is a crucial cornerstone in upholding both curative treatment options and treatment capacity during a pandemic.


Assuntos
COVID-19 , Radioterapia (Especialidade) , Áustria , Humanos , Pandemias , SARS-CoV-2
4.
Cancer Med ; 10(12): 3928-3937, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33973411

RESUMO

BACKGROUND: To permit timely mitigation of adverse effects on overall clinical outcome, it is essential to understand how the pandemic influences distress and health-related quality of life (HRQOL) in cancer patients during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: In this cross-sectional study, adult cancer patients, without COVID-19 symptoms, completed a 13-item questionnaire about the pandemic's impacts on distress and everyday-life; associations with age, sex, or impaired HRQOL were then assessed by binary logistic regressions. In a subsample of patients with HRQOL assessment available from both before and during the pandemic, we evaluated the pandemic's impact on longitudinal changes in HRQOL reported within 6 months before versus during the COVID-19 lockdown using McNemar's test, and thresholds for clinical importance. RESULTS: We consecutively enrolled 240 patients with solid (50%) or hematological (50%) cancers. Median age was 67 years, 46% were females. The majority ranked heeding their health (80%) and keeping their appointment schedule in hospital (78%) as important. Being younger than 60, or aged 60-70 was independently associated with limitations in everyday life (OR = 3.57, p < 0.001; and 2.05, p = 0.038); female individuals and those with restricted emotional functioning were more distressed by the COVID-19 situation (OR = 2.47, p = 0.040; and 3.17, p = 0.019); the latter group was also significantly more concerned about being a patient at risk (OR = 2.21, p = 0.029). Interestingly, in a subsample of patients (n = 47), longitudinal comparisons pre- versus during the pandemic revealed that HRQOL was not substantially affected by the pandemic. CONCLUSION: Particularly younger and female cancer patients, and those with impaired emotional functioning are distressed by COVID-19. During the first COVID-19 lockdown, cancer patients remained predominantly resilient. This analysis highlights the need to mitigate distress situations in vulnerable patients and thereby enhance resilience during pandemics.


Assuntos
COVID-19/psicologia , Neoplasias/psicologia , Qualidade de Vida/psicologia , SARS-CoV-2/isolamento & purificação , Estresse Psicológico/psicologia , Inquéritos e Questionários , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/virologia , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Pandemias , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Fatores de Risco , SARS-CoV-2/fisiologia
5.
Sci Rep ; 11(1): 8639, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883632

RESUMO

Overall survival (OS) of patients with brain metastases treated with hypofractionated (HFSRT) or single-fraction (SRS) radiosurgery depends on several prognostic factors. The aim of this study was to investigate the potential of sex as an independent predictor of OS and evaluate the predictive accuracy of common prognostic scores. Retrospective analysis of 281 consecutive patients receiving radiosurgery of brain metastases was performed. Kaplan-Meier survival curves and Cox proportional hazards models were used to compare OS between SRS and HFSRT and by sex, before and after propensity-score matching (PSM) on key baseline prognostic covariates. Prognostic scores were evaluated using Harrell's concordance index. Median OS was 11 months after both SRS and HFSRT. After PSM, median OS was 12 months after SRS (95% CI: 7.5-16.5) and 9 months after HFSRT (95% CI: 5.0-13.0; p = 0.77). Independent prognostic factors were sex, primary tumor, KPI, and systemic disease status. Median OS was 16 months for women and 7 months for male patients (p < 0.001). After excluding sex specific tumors, PSM revealed a median OS of 16 months for women and 8 months for male patients (p < 0.01). Evaluation of prognostic indices showed BSBM to be the most accurate (Harrell's C = 0.68), followed by SIR (0.61), GPA (0.60), RPA (0.58), and Rades et al. (0.57). OS after HFSRT and SRS did not differ, although PSM revealed a non-significant advantage for SRS. Female sex was found to be a major independent positive prognostic factor for survival, and thus should be considered in the personalized decision-making of brain metastases treatment.


Assuntos
Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/radioterapia , Idoso , Neoplasias Encefálicas/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Radiocirurgia/métodos , Estudos Retrospectivos
6.
Cancer Imaging ; 20(1): 69, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993805

RESUMO

BACKGROUND: Contrast-enhanced high-resolution computed tomography (contrast-CT) is a standard imaging modality following primary concurrent radiochemotherapy (RCT) for response evaluation in patients with head and neck squamous cell carcinoma (HNSCC). We investigated the additional benefit of Fluorine-18-fluorodeoxyglucose ([18F]FDG) - positron emission tomography with computed tomography (PET-CT), if complete response (CR) in the neck based on contrast-CT was considered unsafe by the interdisciplinary tumor board (ITB). METHODS: In a retrospective observational study, patients recorded in the institutional tumor registry with incident advanced HNSCC following first line treatment with RCT were eligible. If contrast-CT results of the neck were equivocal or positive at response evaluation, a neck dissection (ND) was scheduled. While waiting for the ND, a [18F]FDG-PET-CT was performed in addition. The histopathological outcome of ND served as reference criterion. Accuracy parameters including sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for both, contrast-CT and PET-CT, served as main outcome parameters. RESULTS: A total of 41 HNSCC patients with positive or equivocal posttreatment contrast-CT were eligible for post-RCT-ND. Of these, 33 received an additional [18F]FDG-PET-CT prior to surgery. Median interval between completion of RCT and the ([18F]FDG)-PET-CT was 10 weeks. Vital persistent tumor in the neck was histopathologically found in 13 of 33 patients with positive or equivocal posttreatment contrast-CT. For contrast-CT and [18F]FDG-PET-CT, sensitivity was 92.3 and 69.2% and did not differ statistically significantly (p = 0.250) whereas specificity was significantly higher for [18F]FDG-PET-CT compared with contrast-CT (80% vs. 25%, p = 0.001). For contrast-CT and [18F]FDG-PET-CT accuracy, PPV and NPV was 31.7, 12.0,96.7 and 78.9, 27.8,95.0%, respectively. CONCLUSION: A negative [18F]FDG-PET-CT did not improve the exclusion of persistent vital tumor in the neck after primary RCT in comparison with contrast-CT alone. However, a positive [18F]FDG-PET-CT was a considerably better indicator of persistent, vital tumor in the neck than contrast-CT. If, based on the [18F]FDG-PET-CT result, the ND in patients with an uncertain or positive neck response in contrast CT had been omitted, the treatment of persistent nodal disease would have been delayed in 3 of 13 patients. On the other hand, if ND would have only been performed in [18F]FDG-PET-CT positive patients, an unnecessary ND would have been avoided in 11 of 20 patients.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Adulto , Quimiorradioterapia , Feminino , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Metástase Linfática/terapia , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/normas , Compostos Radiofarmacêuticos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia
7.
Front Oncol ; 10: 164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32154167

RESUMO

Cancer stem cells (CSC) are a distinct subpopulation within a tumor. They are able to self-renew and differentiate and possess a high capability to repair DNA damage, exhibit low levels of reactive oxygen species (ROS), and proliferate slowly. These features render CSC resistant to various therapies, including radiation therapy (RT). Eradication of all CSC is a requirement for an effective antineoplastic treatment and is therefore of utmost importance for the patient. This makes CSC the prime targets for any therapeutic approach. Albeit clinical data is still scarce, experimental data and first clinical trials give hope that CSC-targeted treatment has the potential to improve antineoplastic therapies, especially for tumors that are known to be treatment resistant, such as glioblastoma. In this review, we will discuss CSC in the context of RT, describe known mechanisms of resistance, examine the possibilities of CSC as biomarkers, and discuss possible new treatment approaches.

8.
Radiat Oncol ; 14(1): 231, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31852497

RESUMO

BACKGROUND: The present study investigates the intrafractional accuracy of a frameless thermoplastic mask used for head immobilization during stereotactic radiotherapy. Non-invasive masks cannot completely prohibit head movements. Previous studies attempted to estimate the magnitude of intrafractional inaccuracy by means of pre- and postfractional measurements only. However, this might not be sufficient to accurately map also intrafractional head movements. MATERIALS AND METHODS: Intrafractional deviation of mask-fixed head positions was measured in five patients during a total of 94 fractions by means of close-meshed repeated ExacTrac measurements (every 1.4 min) conducted during the entire treatment session. A median of six (range: 4 to 11) measurements were recorded per fraction, delivering a dataset of 453 measurements. RESULTS: Random errors (SD) for the x, y and z axes were 0.27 mm, 0.29 mm and 0.29 mm, respectively. Median 3D deviation was 0.29 mm. Of all 3D intrafractional motions, 5.5 and 0.4% exceeded 1 mm and 2 mm, respectively. A moderate correlation between treatment duration and mean 3D displacement was determined (rs = 0.45). Mean 3D deviation increased from 0.21 mm (SD = 0.26 mm) in the first 2 min to a maximum of 0.53 mm (SD = 0.31 mm) after 10 min of treatment time. CONCLUSION: Pre- and post-treatment measurement is not sufficient to adequately determine the range of intrafractional head motion. Thermoplastic masks provide both reliable interfractional and intrafractional immobilization for image-guided stereotactic hypofractionated radiotherapy. Greater positioning accuracy may be obtained by reducing treatment duration (< 6 min) and applying intrafractional correction. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03896555, Registered 01 April 2019 - retrospectively registered.


Assuntos
Movimentos da Cabeça , Neoplasias de Cabeça e Pescoço/cirurgia , Imobilização/instrumentação , Posicionamento do Paciente/instrumentação , Imagens de Fantasmas , Radiocirurgia/instrumentação , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imobilização/métodos , Máscaras , Movimento , Órgãos em Risco/efeitos da radiação , Posicionamento do Paciente/métodos , Radiocirurgia/métodos , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Tomografia Computadorizada por Raios X/métodos
9.
Strahlenther Onkol ; 194(6): 520-532, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29450591

RESUMO

AIM: of this study is to determine the temporal resolution of therapy-induced pneumonitis, and to assess promoting factors in adjuvant treated patients with unilateral mammacarcinoma. PATIENTS AND METHODS: A total of 100 post-surgery patients were recruited. The cohort was treated by 2 field radiotherapy (2FRT; breast and chest wall, N = 75), 3 field radiotherapy (3FRT; + supraclavicular lymphatic region, N = 8), or with 4 field radiotherapy (4FRT; + parasternal lymphatic region, N = 17). Ninety-one patients received various systemic treatments prior to irradiation. Following an initial screening visit post-RT, two additional visits after 12 and 25 weeks were conducted including radiographic examination. In addition, general anamnesis and the co-medication were recorded. The endpoint was reached as soon as a pneumonitis was developed or at maximum of six months post-treatment. RESULTS: A pneumonitis incidence of 13% was determined. Of 91 patients with prior systemic therapy, 11 patients developed pneumonitis. Smoking history and chronic obstructive pulmonary disease (COPD) appeared to be positive predictors, whereas past pneumonia clearly promoted pneumonitis. Further pneumonitis-promoting predictors are represented by the applied field extensions (2 field radiotherapy [2FRT] < 3 field radiotherapy [3FRT] < 4 field radiotherapy [4FRT]) and the type of combined initial systemic therapies. As a consequence, all of the three patients in the study cohort treated with 4FRT and initial chemotherapy combined with anti-hormone and antibody protocols developed pneumonitis. A combination of the hormone antagonists tamoxifen and goserelin might enhance the risk for pneumonitis. Remarkably, none of the 11 patients co-medicated with statins suffered from pneumonitis. CONCLUSIONS: The rapidly increasing use of novel systemic therapy schedules combined with radiotherapy (RT) needs more prospective studies with larger cohorts. Our results indicate that contribution to pneumonitis occurrence of various (neo)adjuvant therapy approaches followed by RT is of minor relevance, whereas mean total lung doses of >10 Gy escalate the risk of lung tissue complications. The validity of potential inhibitors of therapy-induced pneumonitis as observed for statin co-medication should further be investigated in future trials.


Assuntos
Adenocarcinoma/radioterapia , Neoplasias da Mama/radioterapia , Carcinoma in Situ/radioterapia , Pneumonite por Radiação/epidemiologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Neoplasias da Mama/cirurgia , Carcinoma in Situ/cirurgia , Quimioterapia Adjuvante/efeitos adversos , Estudos de Coortes , Feminino , Gosserrelina/administração & dosagem , Gosserrelina/efeitos adversos , Humanos , Incidência , Mastectomia , Pessoa de Meia-Idade , Estudos Prospectivos , Pneumonite por Radiação/diagnóstico , Radioterapia Adjuvante , Fatores de Risco , Tamoxifeno/administração & dosagem , Tamoxifeno/efeitos adversos
10.
Artigo em Inglês | MEDLINE | ID: mdl-28130028

RESUMO

BACKGROUND: Radiation therapy (RT) of the head and neck region is often accompanied by serious side effects. Research in this area is needed to improve treatment outcomes and ameliorate therapy tolerance. Laboratory rodents are barely matching today's clinical standards in RT research. Yet domestic swine (Sus scrofa domestica) have previously proved suitable for various advanced tests in clinical research and training. We therefore investigated whether S. scrofa domestica is also appropriate for irradiation of the mandible. STUDY DESIGN: A common scheme for irradiation treatment of S. scrofa domestica mandibles in a split-mouth design was acquired by applying computed tomography (CT) scanning under sedation. Basing on close anatomic resemblance, a standard treatment plan comprising 2 opposed irradiation fields could be accomplished. RESULTS: RT was carried out in a clinical environment with 2 × 9 Gy. The resulting operating procedure facilitated complication-free sedation, transport, positioning, CT scanning, and effective irradiation. CONCLUSION: Based on common standards applied for RT in humans, domestic pigs can be employed to progress RT clinical research. Due to their human-like anatomy, physiology, size, and weight, the swine model is expedient for advancing experimental RT of the head and neck area.


Assuntos
Modelos Animais de Doenças , Neoplasias de Cabeça e Pescoço/radioterapia , Mandíbula/efeitos da radiação , Sus scrofa , Animais , Doses de Radiação , Tomografia Computadorizada por Raios X
11.
Proteomics Clin Appl ; 9(11-12): 1069-77, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25914211

RESUMO

The majority of tumor-related deaths are due to metastasis. Despite the clinical importance of understanding metastasis, we lack knowledge of the molecular mechanisms underlying tumor cell spreading and cell survival far from the primary tumor. Elucidating the molecular characteristics of highly metastatic carcinoma cells would help identify biomarkers or therapeutic targets relevant to predicting or combatting metastasis, and for this the phenotype of metastatic cells could be much more important than their genotype. Hence, proteomic approaches have wide potential utility. This review discusses possibilities of analyzing metastasis-specific protein patterns in a range of sample types, including in vitro and in vivo cancer models, and tissues and biological fluids from patients. Proteome approaches can identify proteins involved in regulating the metastatic capacities of tumors.


Assuntos
Neoplasias/metabolismo , Neoplasias/patologia , Proteômica/métodos , Movimento Celular , Humanos , Terapia de Alvo Molecular , Metástase Neoplásica , Neoplasias/sangue , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia
12.
Exp Gerontol ; 54: 75-83, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24468331

RESUMO

A key feature of the aged human immune system is the accumulation of highly differentiated CD8(+)CD28(-) T cells, a phenomenon that negatively influences immune function in the elderly. However, the mechanisms that regulate survival or death of CD8(+)CD28(-) T cells remain incompletely understood. Macroautophagy has been shown to protect cells from unfavorable environmental conditions and extend lifespan of various cells and organisms. In this study, we investigated autophagy in CD8(+)CD28(+) and CD8(+)CD28(-) T cells following T cell receptor (TCR) engagement. We demonstrate that TCR-mediated activation led to a potent induction of autophagy in CD8(+)CD28(+) T cells which was accompanied by an increased activity of the mammalian target of rapamycin complex 1 (mTORC1). This was surprising, as mTORC1 is generally perceived as an inhibitor of autophagy. Inhibition of mTORC1 by rapamycin could still enhance activation-induced autophagy. In contrast, CD8(+)CD28(-) T cells induced autophagy to a significantly lower extent in response to TCR engagement compared to CD8(+)CD28(+) T cells and failed to increase autophagy upon mTORC1 inhibition. In conclusion, we describe for the first time the induction of autophagy in human CD8(+) T cells following TCR engagement and the decreased ability of CD8(+)CD28(-) T cells to induce autophagy, suggesting that they cannot meet the metabolic needs of antigen receptor-mediated activation and are therefore unlikely to survive when confronted by their specific antigens.


Assuntos
Autofagia/fisiologia , Antígenos CD28/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Receptores de Antígenos de Linfócitos T/fisiologia , Idoso , Células Cultivadas , Feminino , Citometria de Fluxo , Humanos , Imunossupressores/farmacologia , Leucócitos Mononucleares/fisiologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/metabolismo , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
13.
Oncoscience ; 1(8): 513-521, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25594058

RESUMO

Metastatic progression of malignant tumors resistant to conventional therapeutic approaches is an ultimate challenge in clinical oncology. Despite the efforts of basic and clinical researchers, there is still no effective treatment schedule to prevent or combat metastatic spread of malignant tumors. This report presents recent findings that could help in the development of targeted therapeutics directed against the most aggressive and treatment-resistant carcinoma cells. It was demonstrated that HNSCC carcinoma cell lines with acquired treatment resistance possessed increased number of cells with carcinoma stem cell (CSC) properties. Furthermore, resistant cells were characterized by increased expression of Rac1, enhanced cell migration, and accelerated release of proangio- and vasculogenic factors (VEGF-A) and influence on endothelial cell (HMEC-1) migration. Inhibition of Rac1 signaling in the treatment-resistant carcinoma cells can interrupt metastatic process due to anoikis restoration and decrease of cell migration. It is also suggested that carcinoma cells with repressed survival capacities will be characterized by reduced release of proangiogenic factors, resulting in the decrease of endothelial cell migration. Therefore targeting of Rac1-related pathways may be considered as a promising therapeutic approach to prevent or combat metastatic lesions.

14.
Exp Gerontol ; 47(9): 749-53, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22790019

RESUMO

The immune system undergoes profound age-related changes, including a gradual increase in the production and circulation of proinflammatory cytokines. Despite the known capacity of fibroblasts to produce cytokines, little is known so far about the inflammatory response of fibroblasts to cellular stress such as viral and/or bacterial infection in the context of aging. Therefore the aim of this study was to analyze the levels of IL6 and IL8 secretion in supernatants of human skin fibroblasts from young and elderly persons. Cytokine and chemokine secretion was analyzed before and after in vitro infection of the cells with Cytomegalovirus (CMV) and/or stimulation with Lipopolysaccharide (LPS). The exposure of fibroblasts to these agents caused inflammatory changes, reflected by the secretion of both the cytokine IL6 and the chemokine IL8 by fibroblasts from young as well as elderly persons. The cytokine/chemokine production induced by either agent alone could be further increased by co-stimulation of the cells with both stimuli. The level of protein secretion was dependent on the chronological age of the fibroblasts. Stimulated human skin fibroblasts from elderly donors produced higher amounts of IL6 as well as IL8 than fibroblasts from young donors. These differences were more pronounced for IL6 than for IL8. The inflammatory response of fibroblasts to stimulation differed among donors and did not correspond to the responsiveness of whole blood derived from the same person. In summary lifelong CMV-infection may act as an in vivo trigger for inflammatory changes by increasing the inflammatory response to bacterial products such as LPS. It may thus contribute to age-related inflammatory processes, referred to as 'inflamm-aging'.


Assuntos
Envelhecimento/fisiologia , Fibroblastos/metabolismo , Inflamação/fisiopatologia , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Adulto , Idoso de 80 Anos ou mais , Western Blotting , Células Cultivadas , Infecções por Citomegalovirus/fisiopatologia , Feminino , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Adulto Jovem
15.
Aging Cell ; 11(4): 579-87, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22435726

RESUMO

The life-long homeostasis of memory CD8(+) T cells as well as persistent viral infections have been shown to facilitate the accumulation of highly differentiated CD8(+) CD28(-) T cells, a phenomenon that has been associated with an impaired immune function in humans. However, the molecular mechanisms regulating homeostasis of CD8(+) CD28(-) T cells have not yet been elucidated. In this study, we demonstrate that the miR-23∼24∼27 cluster is up-regulated during post-thymic CD8(+) T-cell differentiation in humans. The increased expression of miR-24 in CD8(+) CD28(-) T cells is associated with decreased expression of the histone variant H2AX, a protein that plays a key role in the DNA damage response (DDR). Following treatment with the classic chemotherapeutic agent etoposide, a topoisomerase II inhibitor, apoptosis was increased in CD8(+) CD28(-) when compared to CD8(+) CD28(+) T cells and correlated with an impaired DDR in this cell type. The reduced capacity of CD8(+) CD28(-) T cell to repair DNA was characterized by the automated fluorimetric analysis of DNA unwinding (FADU) assay as well as by decreased phosphorylation of H2AX at Ser139, of ATM at Ser1981, and of p53 at Ser15. Interleukin (IL)-15 could prevent etoposide-mediated apoptosis of CD8(+) CD28(-) T cells, suggesting a role for IL-15 in the survival and the age-dependent accumulation of CD8(+) CD28(-) T cells in humans.


Assuntos
Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Dano ao DNA , Etoposídeo/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Adulto , Idoso , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular , Reparo do DNA , Histonas/química , Histonas/metabolismo , Humanos , Técnicas In Vitro , Interleucina-15/metabolismo , Células Jurkat , Fosforilação , Serina/química , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos
16.
J Clin Immunol ; 31(2): 137-46, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21243520

RESUMO

The immune system is affected by the aging process and undergoes significant age-related changes, termed immunosenescence. Different T cell subsets are affected by this process. Alterations within the bone marrow and thymus lead to a shift in the composition of the T cell repertoire from naïve to antigen-experienced T cells, thereby compromising the diversity of the T cell pool. Additional infection with latent pathogens such as cytomegalovirus aggravates this process. In this review, we focus on the major age-related changes that occur in the naïve and the antigen-experienced T cell population. We discuss the mechanisms responsible for the generation and maintenance of these subsets and how age-related changes can be delayed or prevented by clinical interventions.


Assuntos
Envelhecimento/imunologia , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Animais , Antígenos/imunologia , Humanos , Memória Imunológica , Imunomodulação
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