RESUMO
The development of peptide vaccines aimed at enhancing immune responses against tumor cells is becoming a promising area of research. Human telomerase reverse transcriptase (hTERT) is an ideal universal target for novel immunotherapies against cancers. The aim of this work was to verify whether the multiple antigen peptides (MAP) based on HLA-A0201-restricted CTL epitopes of hTERT could trigger a better and more sustained CTL response and kill multiple types of hTERT-positive tumor cells in vitro and ex vivo. Dendritic cells (DC) pulsed with MAP based on HLA-A0201-restricted CTL epitopes of hTERT (hTERT-540, hTERT-865 and hTERT-572Y) were used to evaluate immune responses against various tumors and were compared to the immune responses resulting from the use of corresponding linear epitopes and a recombinant adenovirus-hTERT vector. A 4-h standard (51) Cr-release assay and an ELISPOT assay were used for both in vitro and ex vivo analyses. Results demonstrated that targeting hTERT with an adenovector was the most effective way to stimulate a CD8(+) T cell response. When compared with linear hTERT epitopes, MAP could trigger stronger hTERT-specific CTL responses against tumor cells expressing hTERT and HLA-A0201. In contrast, the activated CTL could neither kill the hTERT-negative tumor cells, such as U2OS cells, nor kill HLA-A0201 negative cells, such as HepG2 cells. We also found that these peptide-specific CTL could not kill autologous lymphocytes and DC with low telomerase activity. Our results indicate that MAP from hTERT can be exploited for cancer immunotherapy.
Assuntos
Antineoplásicos/farmacologia , Epitopos de Linfócito T/imunologia , Antígeno HLA-A2/imunologia , Neoplasias/terapia , Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Telomerase/imunologia , Animais , Antineoplásicos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/farmacologia , Linhagem Celular Tumoral , Células Dendríticas/imunologia , Vetores Genéticos/imunologia , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/imunologia , Peptídeos/farmacologia , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
BACKGROUND: Telomerase is commonly recognized as an effective anticancer target. The human telomerase reverse transcriptase (hTERT), the rate-limiting component of telomerase, is expressed in most malignant tumors, but it is not found in most normal somatic cells. Here, we report a real-time and noninvasive method to monitor tumor response to a lentivirus-based hTERT-conditional suicidal gene therapy. METHODS: In this study, we constructed a lentivirus system in which an optimized hTERT promoter was used to drive the expression of the cytosine deaminase (CD) gene, one of the suicide genes, and a green fluorescent protein (GFP) reporter gene (pLenti-CD/GFP). The lentivirus was used to infect telomerase-positive or telomerase-negative cell lines. In vitro and in vivo experiments were conducted to analyze the dynamic processes of exogenous gene expression noninvasively in cell culture and living animals in real time via optical imaging. RESULTS: The lentivirus was able to express the CD gene and GFP in telomerase-positive tumor cells and significantly decrease cell proliferation after the use of prodrug 5-flucytosine. However, it could not express GFP and CD in telomerase-negative cell lines, nor could it induce any suicidal effect in those cells. The in vivo study showed that telomerase-positive tumors can be visualized after intratumor injection of the lentivirus in tumor-bearing nude mice via an optical imaging system. Significant tumor growth suppression was observed in telomerase-positive tumors. CONCLUSIONS: Collectively, this technology provides a valuable, noninvasive method to evaluate the real-time therapeutic response of tumors in vivo.
Assuntos
Sistemas Computacionais , Citosina Desaminase/metabolismo , Monitoramento de Medicamentos/métodos , Terapia Genética/métodos , Neoplasias/terapia , Telomerase/genética , Animais , Linhagem Celular Tumoral , Citosina Desaminase/genética , Flucitosina , Genes Reporter , Genes Transgênicos Suicidas , Proteínas de Fluorescência Verde/genética , Humanos , Lentivirus/genética , Camundongos , Camundongos Nus , Neoplasias/genética , Regiões Promotoras Genéticas , Resultado do Tratamento , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Macrophages are widely distributed innate immune cells that play indispensable roles in the innate and adaptive immune response to pathogens and in-tissue homeostasis. Macrophages can be activated by a variety of stimuli and polarized to functionally different phenotypes. Two distinct subsets of macrophages have been proposed, including classically activated (M1) and alternatively activated (M2) macrophages. M1 macrophages express a series of proinflammatory cytokines, chemokines, and effector molecules, such as IL-12, IL-23, TNF-α, iNOS and MHCI/II. In contrast, M2 macrophages express a wide array of anti-inflammatory molecules, such as IL-10, TGF-ß, and arginase1. In most tumors, the infiltrated macrophages are considered to be of the M2 phenotype, which provides an immunosuppressive microenvironment for tumor growth. Furthermore, tumor-associated macrophages secrete many cytokines, chemokines, and proteases, which promote tumor angiogenesis, growth, metastasis, and immunosuppression. Recently, it was also found that tumor-associated macrophages interact with cancer stem cells. This interaction leads to tumorigenesis, metastasis, and drug resistance. So mediating macrophage to resist tumors is considered to be potential therapy.
Assuntos
Macrófagos/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Microambiente Tumoral/imunologia , Animais , Progressão da Doença , Humanos , Macrófagos/metabolismo , Neoplasias/terapiaRESUMO
Following the publication of this article, an interested reader drew to the authors' attention that two images in Fig. 1B (the a and d panels) appeared to represent the same clone, albeit with different intensities and the panels were cropped differently. The authors were able to confirm that Figs. 1B(a) and B(d) were inadvertently selected from the same set of images but with different exposure times: Owing to an error in data handling, a wrong image was chosen during the grouping the figures. The corrected version of Fig. 1 is shown on the next page, featuring the correct image for Fig. 1B(d). The authors regret that this error was not picked up upon before the paper was sent to press, although the error did not affect the major conclusions reported in the paper. The authors thank the Editor of International Journal of Oncology for allowing them the opportunity to publish a Corrigendum. and regret any inconvenience caused to the readership. [the origional article was published on International Journal of Oncology 40: 16011609, 2012; DOI: 10.3892/ijo.2012.1338].
RESUMO
Based on a long-term simulated acid rain experiment, soil N2O emission fluxes were measured using static chambers and the gas chromatography method in a coniferous and broadleaved mixed forest and a monsoon evergreen broadleaved forest in southern China. During the five-year observation periods (2014-2018), soil N2O emission fluxes in the two forests showed obvious seasonal variation. The soil N2O emission fluxes in wet season were significantly higher than that in dry season, with a large annual variation. Due to the decreases of precipitation, soil N2O emission fluxes of the two forests in 2017 and 2018 were generally low. Soil N2O emission flux was positively correlated with soil temperature and soil moisture. In the monsoon evergreen broadleaved forest, soil N2O emission flux in the control plot was 12.6 µg N2O·m-2·h-1. Soil N2O emission fluxes under the pH 3.5 and pH 3.0 treatments increased by 42.9% and 61.1%, respectively. Soil N2O emission was significantly increased under simulated acid rain in the monsoon evergreen broadleaved forest. Acid rain promoted soil N2O emission in the coniferous and broadleaved mixed forest, but without significant difference among the treatments. Under the scenario of increasing acid rain, soil N2O emission fluxes in typical subtropical southern China forests would increase, and the magnitude of such increase was different among forest types.
Assuntos
Chuva Ácida , Solo , China , Florestas , Óxido Nitroso/análiseRESUMO
OBJECTIVES: Severe viral hepatitis B is a disease associated with significant morbidity and mortality. Clinical controlled trials show that the efficacy of treatment of severe viral hepatitis B with glucocorticoids remains debatable. Therefore, we carried out this meta-analysis to evaluate the safety, efficacy, and side effects of glucocorticoid therapy for severe viral hepatitis B. METHODS: We searched PubMed, Medline, Embase, Cochrane Library, and Google Scholar for randomized-controlled trials published before April 2012 in which glucocorticoid therapy was compared with routine treatment for severe viral hepatitis B. The primary outcome was the survival rate of the two groups. RESULTS: We selected eight controlled clinical trials, which included 597 patients. We recorded a benefit of glucocorticoid treatment on the survival rate of patients with severe viral hepatitis B (597 patients) [risk ratio (RR)=1.188, 95% confidence interval (CI) 1.030-1.369, P=0.018]. The benefit was most noticeable in patients at the stage of preliver failure (409 patients) (RR=1.275, 95% CI 1.077-1.510, P=0.005), whereas there was no efficacy for patients with liver failure (188 patients) (RR=1.008, 95% CI 0.774-1.312, P=0.955). Glucocorticoid treatment was not associated with the development of secondary infection and bleeding. CONCLUSION: Treatment with glucocorticoids can significantly increase the survival rate of patients with severe hepatitis B. The benefit was most noticeable in patients at the stage of preliver failure. However, the incidence of secondary infection and bleeding did not change significantly. This finding suggests that prompt and timely glucocorticoid treatment is crucial.
Assuntos
Antivirais/uso terapêutico , Glucocorticoides/uso terapêutico , Hepatite B/tratamento farmacológico , Antivirais/efeitos adversos , Glucocorticoides/efeitos adversos , Hepatite B/diagnóstico , Hepatite B/imunologia , Hepatite B/mortalidade , Humanos , Razão de Chances , Fatores de Risco , Índice de Gravidade de Doença , Análise de Sobrevida , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Activation of telomerase is involved in carcinogenesis in most types of cancers. However, the prognostic value of telomerase activity (TA) in patients with gastric carcinoma (GC) remains controversial. We conducted a meta-analysis to assess the relationship between TA and the clinical outcome of GC. A meta-analysis of 18 studies (886 patients) was performed to evaluate the association between TA and metastasis-related parameters in GC patients by searching databases, including PubMed, MEDLINE, EMBASE, Web of Science databases, Cochrane Library and the Chinese Biomedical Literature database (CBM) (last search updated in October 2011). We used the odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between TA and metastasis of GC. Our analysis results indicated that high telomerase activity expression tended to be associated with the presence of lymph node metastasis (866 patients) (OR=2.03, 95% CI 1.21-3.39, p=0.007), the depth of invasion (886 patients) (OR=1.87, 95% CI 1.30-2.70, p=0.0007), distant metastasis (407 patients) (OR=2.71, 95% CI 1.59-4.63, p=0.0002), tumor size (466 patients) (OR=2.14, 95% CI 1.31-3.50, p=0.002) and TNM stage (711 patients) (OR=2.39, 95% CI 1.30-4.41, p=0.005). However, high TA expression was not associated with the presence of histologic differentiation (791 patients) (OR=1.51, 95% CI 0.73-3.11, p=0.26). In conclusion, telomerase overexpression not only plays a key role in primary initiation, but also promotes invasion and metastatic progression of GC. These findings raise the possibility of using TA to screen for the prognosis of gastric cancer.
RESUMO
Heparanase is an endoglycosidase that degrades heparan sulfate, the main polysaccharide constituent of the extracellular matrix and basement membrane. The expression of heparanase is associated with invasion, as well as the angiogenic and metastatic potential of diverse malignant tumors. We used RNA interference strategies to evaluate the role of human heparanase in a liver cancer cell line and to explore the therapeutic potential of its specific targeting. Using an online siRNA tool, we designed three small interfering RNA sequences to target the heparanase coding region and cloned them into the pGenesil-1 vector. The siRNA vectors were transfected into HepG2 liver cancer cells. Heparanase expression was measured by real-time RT-PCR and Western blotting. Cell proliferation was detected by MTT staining and plate colony formation. Cell cycle analysis was performed by flow cytometry. In vitro invasion was measured by Matrigel invasion assay. We also analyzed tumorigenicity in heparanase-suppressed HepG2 cells in nude mice. We found that siRNA-1 (1214-1232) and siRNA-3 (611-629) targeting heparanase significantly downregulated the expression of heparanase in HepG2 liver cancer cells. Compared with its controls, siRNA-1 or siRNA-3 vectors efficiently inhibi-ted the proliferation and invasion of HepG2 liver cancer cells in vitro and tumorigenesis in vivo. These results suggest that heparanase-specific RNA interference has potential value as a novel therapeutic agent for human liver cancer.
Assuntos
Carcinoma Hepatocelular/terapia , Proliferação de Células , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Terapia Genética/métodos , Glucuronidase/metabolismo , Neoplasias Hepáticas/terapia , Interferência de RNA , Animais , Sequência de Bases , Western Blotting , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Ciclo Celular , Regulação para Baixo , Citometria de Fluxo , Glucuronidase/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Células NIH 3T3 , Invasividade Neoplásica , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Tempo , Transdução Genética , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Peptide vaccination for cancer immunotherapy requires an ideal immune response induced by epitope peptides derived from tumor-associated antigens (TAA). Heparanase is broadly expressed in various advanced tumors. Accumulating evidence suggests that heparanase can serve as a universal TAA for tumor immunotherapy. However, due to the low immunogenicity of peptide vaccines, an ideal immune response against tumors usually cannot be elicited in patients. To increase the immunogenicity of peptide vaccines, we designed three 4-branched multiple antigenic peptides (MAP) on the basis of the human leukocyte antigen (HLA)-A2-restricted cytotoxic T lymphocyte (CTL) epitopes of human heparanase that we identified previously as antigen carriers. Our results show that MAP vaccines based on the HLA-A2-restricted CLT epitopes of human heparanase were capable of inducing HLA-A2-restricted and heparanase-specific CTL in vitro and in mice. Moreover, compared with their corresponding linear peptides, heparanase MAP vaccines elicited much stronger lysis of tumor cells by activating CD8(+) T lymphocytes and increasing the releasing of IFN-γ. However, these heparanase-specific CTLs did not lyse heparanase-expressing autologous lymphocytes and dendritic cells, which confirm the safety of these MAP vaccines. Therefore, our findings indicate that MAP vaccines based on CTL epitopes of human heparanase can be used as potent immunogens for tumor immunotherapy because of advantages such as broad spectrum, high effectiveness, high specificity, and safety.