RESUMO
BACKGROUND: A novel prediction algorithm is needed for the identification of effective tumor associated mutated neoantigens. Only those with no homology to self wild type antigens are true predicted neoantigens (TPNAs) and can elicit an antitumor T cell response, not attenuated by central tolerance. To this aim, the mutational landscape was evaluated in HCV-associated hepatocellular carcinoma. METHODS: Liver tumor biopsies and adjacent non-tumor liver tissues were obtained from 9 HCV-chronically infected subjects and subjected to RNA-Seq analysis. Mutant peptides were derived from single nucleotide variations and TPNAs were predicted using two prediction servers (e.g. NetTepi and NetMHCstabpan) by comparison with corresponding wild-type sequences, non-related self and pathogen-related antigens. Immunological confirmation was obtained in preclinical as well as clinical setting. RESULTS: The development of such an improved algorithm resulted in a handful of TPNAs despite the large number of predicted neoantigens. Furthermore, TPNAs may share homology to pathogen's antigens and be targeted by a pre-existing T cell immunity. Cross-reactivity between such antigens was confirmed in an experimental pre-clinical setting. Finally, TPNAs homologous to pathogen's antigens were found in the only HCC long-term survival patient, suggesting a correlation between the pre-existing T cell immunity specific for these TPNAs and the favourable clinical outcome. CONCLUSIONS: The new algorithm allowed the identification of the very few TPNAs in cancer cells, and those targeted by a pre-existing immunity strongly correlated with long-term survival. Only such TPNAs represent the optimal candidates for immunotherapy strategies.
Assuntos
Antígenos de Neoplasias/imunologia , Carcinoma Hepatocelular/imunologia , Neoplasias Hepáticas/imunologia , Idoso , Sequência de Aminoácidos , Animais , Sítios de Ligação , Sobreviventes de Câncer , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virologia , Linhagem Celular , Simulação por Computador , Modelos Animais de Doenças , Epitopos/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Hepacivirus/fisiologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunidade , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/virologia , Camundongos Endogâmicos C57BL , Mutação/genética , Reprodutibilidade dos Testes , Homologia de Sequência de Aminoácidos , Microambiente Tumoral/imunologiaRESUMO
BACKGROUND: Loss of CBX7 expression has been described in several malignant neoplasias, including human colon and thyroid carcinomas proposing CBX7 as a tumor suppressor gene with a key role in cancer progression. This role is supported from the development of benign and malignant neoplasias in Cbx7 null mice. The aim of our work has been to investigate the mechanisms underlying the CBX7 oncosuppressor activity by analyzing the microRNAs (miRNAs) regulated by CBX7. METHODS: The miRNA expression profiles of the mouse embryonic fibroblasts (MEFs) null for Cbx7 and the wild-type counterpart were analyzed by the miRNACHIP microarray and then validated by qRT-PCR. To asses KRAS as target of miR-155 we evaluated the protein levels after transfection of the synthetic miR-155. Human colon carcinoma samples have been investigated for the expression of CBX7 and miR-155. RESULTS: Twenty miRNAs were found upregulated and nine, including miR-155, downregulated in cbx7-null MEFS in comparison with the wild-type ones. Then, we focused on miR-155 since several studies have shown its deregulated expression in several human malignancies and, moreover, was the most downregulated miRNA. Subsequently, we searched for miR-155 target genes demonstrating that KRAS protein levels are directly modulated by miR-155. A direct significant correlation (r = 0.6779) between CBX7 and miR-155 expression levels was found in a set of human colon carcinoma tissue samples. CONCLUSION: miR-155 is positively regulated by CBX7 in MEFs and colon carcinomas, and has KRAS as one of the target genes likely accounting for the anti-apoptotic activity ascribed to miR-155 in some tissue contexts.
Assuntos
Neoplasias do Colo/metabolismo , Fibroblastos/metabolismo , Genes ras , MicroRNAs/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Neoplasias do Colo/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , CamundongosRESUMO
The quest for alternative drugs with respect to the well-known cis-platin and its derivatives, which are still used in more than 50% of the treatment regimens for patients suffering from cancer, is highly needed. In this context, organometallic compounds, which are defined as metal complexes containing at least one direct covalent metal-carbon bond, have recently been found to be promising anticancer drug candidates. A series of new metallocene complexes with scandium, yttrium, and neodymium have been prepared and characterized. Some of these compounds show a very interesting anti-proliferative activity in triple negative breast cancer cell line (MDA.MB231) and the non-hormone sensitive prostate cancer cell line (DU145). Moreover, the interaction of some of them with biological membranes, evaluated using liposomes as bio-membrane mimetic model systems, seems to be relevant. The biological activity of these compounds, particularly those based on yttrium, already effective at low concentrations on both cancer cell lines, should be taken into account with regard to new therapeutic approaches in anticancer therapy.
Assuntos
Antineoplásicos/síntese química , Neodímio/química , Compostos Organometálicos/síntese química , Escândio/química , Ítrio/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Compostos Organometálicos/química , Compostos Organometálicos/farmacologiaRESUMO
BACKGROUND: The tumor immunosuppressive microenvironment represents a major obstacle to an effective tumor-specific cellular immune response. METHODS: In the present study, the counterbalance effect of a novel metronomic chemotherapy protocol on such an immunosuppressive microenvironment was evaluated in a mouse model upon sub-cutaneous ectopic implantation of B16 melanoma cells. The chemotherapy consisted of a novel multi-drug cocktail including taxanes and alkylating agents, administered in a daily metronomic fashion. The newly designed strategy was shown to be safe, well tolerated and significantly efficacious. RESULTS: Treated animals showed a remarkable delay in tumor growth and prolonged survival as compared to control group. Such an effect was directly correlated with CD4(+) T cell reduction and CD8(+) T cell increase. Furthermore, a significant reduction in the percentage of both CD25(+)FoxP3(+) and CD25(+)CD127(low) regulatory T cell population was found both in the spleens and in the tumor lesions. Finally, the metronomic chemotherapy induced an intrinsic CD8(+) T cell response specific to B16 naturally expressed Trp2 TAA. CONCLUSION: The novel multi-drug daily metronomic chemotherapy evaluated in the present study was very effective in counterbalancing the immunosuppressive tumor microenvironment. Consequently, the intrinsic anti-tumor T cell immunity could exert its function, targeting specific TAA and significantly containing tumor growth. Overall, the results show that this represents a promising adjuvant approach to significantly enhance efficacy of intrinsic or vaccine-elicited tumor-specific cellular immunity.
Assuntos
Administração Metronômica , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Melanoma Experimental/tratamento farmacológico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Calreticulina/metabolismo , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , ELISPOT , Feminino , Interferon gama/biossíntese , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Análise de Sobrevida , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
Pancreatic adenocarcinoma remains an unresolved therapeutic challenge because of its intrinsically refractoriness to both chemo- and radiotherapy due to the complexity of signaling and the activation of survival pathways in cancer cells. Recent studies have demonstrated that the combination of some drugs, targeting most of aberrant pathways crucial for the survival of pancreatic cancer cells may be a valid antitumor strategy for this cancer. Type I interferons (IFNs) may have a role in the pathogenesis and progression of pancreatic adenocarcinoma, but the limit of their clinical use is due to the activation of tumor resistance mechanisms, including JAK-2/STAT-3 pathway. Moreover, aberrant constitutive activation of STAT-3 proteins has been frequently detected in pancreatic adenocarcinoma. The selective targeting of these cell survival cascades could be a promising strategy in order to enhance the antitumor effects of type I IFNs. The activation of peroxisome proliferator-activated receptor γ (PPAR-γ), on the other hand, has a suppressive activity on STAT-3. In fact, PPAR-γ agonists negatively modulate STAT-3 through direct and/or indirect mechanisms in several normal and cancer models. This review provides an overview on the current knowledge about the molecular mechanisms and antitumor activity of these two promising classes of drugs for pancreatic cancer therapy. Finally, the synergistic antiproliferative activity of combined IFN-ß and troglitazone treatment on pancreatic cancer cell lines, evaluated in vitro, and the consequent potential clinical applications will be discussed.
Assuntos
Interferon Tipo I/fisiologia , PPAR gama/fisiologia , Neoplasias Pancreáticas/tratamento farmacológico , Transdução de Sinais/fisiologia , Animais , Proliferação de Células , Humanos , Interferon beta/uso terapêutico , PPAR gama/agonistas , Neoplasias Pancreáticas/etiologia , Neoplasias Pancreáticas/patologiaRESUMO
Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and represents the third and the fifth leading cause of cancer-related death worldwide in men and women, respectively. Hepatitis B virus (HBV) and hepatitis C virus (HCV) chronic infections account for pathogenesis of more than 80 % of primary HCC. HCC prognosis greatly varies according to stage at beginning of treatment, but the overall 5-year survival rate is approximately 5-6 %. Given the limited number of effective therapeutic strategies available, immunotherapies and therapeutic cancer vaccines may help in improving the clinical outcome for HCC patients. However, the few clinical trials conducted to date have shown contrasting results, indicating the need for improvements. In the present study, a novel combinatorial strategy, based on metronomic chemotherapy plus vaccine, is evaluated in a mouse model. The chemotherapy is a multi-drug cocktail including taxanes and alkylating agents, which is administered in a metronomic-like fashion. The vaccine is a multi-peptide cocktail including HCV as well as universal tumor antigen TERT epitopes. The combinatorial strategy designed and evaluated in the present study induces an enhanced specific T cell response, when compared to vaccine alone, which correlates to a reduced Treg frequency. Such results are highly promising and may pave way to relevant improvements in immunotherapeutic strategies for HCC and beyond.
Assuntos
Administração Metronômica , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Vacinas Anticâncer/administração & dosagem , Carcinoma Hepatocelular/terapia , Hepacivirus/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Hepatite C/imunologia , Neoplasias Hepáticas/terapia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/imunologia , Alquilantes/uso terapêutico , Animais , Antígenos Virais/imunologia , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/imunologia , Células Cultivadas , Terapia Combinada , Modelos Animais de Doenças , Feminino , Hepatite B/complicações , Hepatite C/complicações , Humanos , Epitopos Imunodominantes/metabolismo , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/imunologia , Ativação Linfocitária , Masculino , Camundongos Endogâmicos C57BL , Taxoides/uso terapêutico , Telomerase/imunologia , Telomerase/metabolismoRESUMO
The antitumor activity of LPS was first described by Dr. William Coley. However, its role in lung cancer remains unclear. The aim of our study was to elucidate the dose-dependent effects of LPS (0.1-10 µg/mouse) in a mouse model of B16-F10-induced metastatic lung cancer. Lung tumor growth increased at 3 and 7 d after the administration of low-dose LPS (0.1 µg/mouse) compared with control mice. This was associated with an influx of plasmacytoid dendritic cells (pDCs), regulatory T cells, myeloid-derived suppressor cells, and CD8(+) regulatory T cells. In contrast, high-dose LPS (10 µg/mouse) reduced lung tumor burden and was associated with a greater influx of pDCs, as well as a stronger Th1 and Th17 polarization. Depletion of pDCs during low-dose LPS administration resulted in a decreased lung tumor burden. Depletion of pDCs during high-dose LPS treatment resulted in an increased tumor burden. The dichotomy in LPS effects was due to the phenotype of pDCs, which were immunosuppressive after the low-dose LPS, and Th1- and T cytotoxic-polarizing cells after the high-dose LPS. Adoptive transfer of T cells into nude mice demonstrated that CD8(+) T cells were responsible for pDC recruitment following low-dose LPS administration, whereas CD4(+) T cells were required for pDC influx after the high-dose LPS. In conclusion, our data suggest differential effects of low-dose versus high-dose LPS on pDC phenotype and tumor progression or regression in the lungs of mice.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Lipopolissacarídeos/farmacologia , Neoplasias Pulmonares/patologia , Melanoma Experimental/patologia , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/transplante , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/patologia , Progressão da Doença , Relação Dose-Resposta Imunológica , Feminino , Lipopolissacarídeos/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfonodos/patologia , Ativação Linfocitária/efeitos dos fármacos , Teste de Cultura Mista de Linfócitos , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/imunologia , Camundongos , Camundongos Nus , Baço/efeitos dos fármacos , Baço/imunologia , Baço/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/patologia , Linfócitos T Reguladores/transplante , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/patologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/patologiaRESUMO
In the last few years, the field of tumor immunology has significantly expanded and its boundaries, never particularly clear, have become less distinct. Although the immune system plays an important role in controlling tumor growth, it has also become clear that tumor growth can be promoted by inflammatory immune responses. A good example that exemplifies the ambiguous role of the immune system in cancer progression is represented by interleukin 18 (IL-18) that was first identified as an interferon-γ-inducing factor (IGIF) involved in T helper type-1 (Th1) immune response. The expression and secretion of IL-18 have been observed in various cell types from immune cells to circulating cancer cells. In this review we highlighted the multiple roles played by IL-18 in immune regulation, cancer progression and angiogenesis and the clinical potential that may result from such understanding.
Assuntos
Transformação Celular Neoplásica/patologia , Sistema Imunitário/imunologia , Interleucina-18/metabolismo , Neoplasias/imunologia , Neoplasias/patologia , Neovascularização Patológica/imunologia , Animais , Humanos , Neoplasias/metabolismoRESUMO
We report here the results of studies aimed to investigate the involvement of serotonin receptor 7 subtype (5-HT7-R) in the modulation of emotional response in Naples High-Excitability (NHE) rat, a validated model for hyperactivity and impaired attention. A range of dosages (0.0, 0.125, 0.250, or 0.500 mg/kg) of LP-211, a selective agonist of 5-HT7-Rs, has been evaluated in animals at different age (adolescence and adulthood). Male NHE and random bred (NRB) control rats were tested in an Elevated Zero-Maze (EZM) after LP-211 treatment in two different regimens: at the issue of adolescent, subchronic exposure (14 intraperitoneal [i.p.] injections, once/day, pnd 31-44, tested on pnd 45--Exp. 1) or as adult, acute effect (15 min after i.p. injection--Exp. 2). Adolescent, subchronic LP-211 at 0.500 mg/kg dosage increased the frequency of head-dips only in NHE rats. Drug effect on time spent and entries in open EZM quadrants were revealed with adult, acute administration of 0.125 mg/kg LP-211 (both strains), indicating a tendency toward anxiolytic effects. In conclusion, data demonstrate that subchronic stimulation of 5-HT7-Rs during prepuberal period increases novelty-seeking/risk-taking propensity in NHE adults. These sequels are revealing increased disinhibition and/or motivation to explore in the NHE rats, which are characterized by a hyperactive dopaminergic system. These data may open new perspectives in studying mechanism of risk-seeking behavior.
Assuntos
Emoções/efeitos dos fármacos , Piperazinas/farmacologia , Receptores de Serotonina/metabolismo , Assunção de Riscos , Agonistas do Receptor de Serotonina/farmacologia , Fatores Etários , Animais , Atenção/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Polyinosinic-polycytidylic acid (poly I:C), a TLR3 ligand, is currently being tested in human clinical trials as an adjuvant to anti-cancer vaccines and in combination with other therapies. However, little is known about its activity in established pulmonary metastasis. The aim of our study was to elucidate the effect of poly I:C (1, 10, or 100 µg/mouse) in a mouse model of B16-F10-induced metastatic lung cancer. Lung tumor growth was arrested after a single administration of poly I:C. This was associated with higher influx of mature dendritic cells (DCs), which drove toward a Th1-like, Th17-like, and cytotoxic immune environment. The interference with IFN type I receptor signaling by means of a specific mAb reversed poly I:C-mediated tumor regression due to lower presence of myeloid DCs, cytotoxic DCs (CD11c(+)CD8(+)), NKT cells, CD8(+) T cells, and Th1-like cytokines. Moreover, the adoptive transfer of poly I:C-activated bone marrow-derived DCs into tumor-bearing mice resulted in activities similar to those of the systemic administration of poly I:C on lung tumor burden. In conclusion, our data prove that poly I:C has potential anti-tumor activity in a mouse model of established pulmonary metastasis. The activation of DCs and the production of IFN type I are responsible for an effective T cytotoxic immune response against metastatic lung cancer progression after poly I:C treatment.
Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Melanoma Experimental/patologia , Melanoma Experimental/prevenção & controle , Poli I-C/administração & dosagem , Transferência Adotiva , Animais , Antineoplásicos/uso terapêutico , Transplante de Medula Óssea/imunologia , Transplante de Medula Óssea/patologia , Células Cultivadas , Células Dendríticas/transplante , Feminino , Neoplasias Pulmonares/patologia , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Poli I-C/uso terapêuticoRESUMO
CD73 is a cell surface enzyme that suppresses T cell-mediated immune responses by producing extracellular adenosine. Growing evidence suggests that targeting CD73 in cancer may be useful for an effective therapeutic outcome. In this study, we demonstrate that administration of a specific CD73 inhibitor, adenosine 5'-(α,ß-methylene)diphosphate (APCP), to melanoma-bearing mice induced a significant tumor regression by promoting the release of Th1- and Th17-associated cytokines in the tumor microenvironment. CD8+ T cells were increased in melanoma tissue of APCP-treated mice. Accordingly, in nude mice APCP failed to reduce tumor growth. Importantly, we observed that after APCP administration, the presence of B cells in the melanoma tissue was greater than that observed in control mice. This was associated with production of IgG2b within the melanoma. Depletion of CD20+ B cells partially blocked the anti-tumor effect of APCP and significantly reduced the production of IgG2b induced by APCP, implying a critical role for B cells in the anti-tumor activity of APCP. Our results also suggest that APCP could influence B cell activity to produce IgG through IL-17A, which significantly increased in the tumor tissue of APCP-treated mice. In support of this, we found that in melanoma-bearing mice receiving anti-IL-17A mAb, the anti-tumor effect of APCP was ablated. This correlated with a reduced capacity of APCP-treated mice to mount an effective immune response against melanoma, as neutralization of this cytokine significantly affected both the CD8+ T cell- and B cell-mediated responses. In conclusion, we demonstrate that both T cells and B cells play a pivotal role in the APCP-induced anti-tumor immune response.
Assuntos
5'-Nucleotidase/antagonistas & inibidores , 5'-Nucleotidase/fisiologia , Difosfato de Adenosina/análogos & derivados , Linfócitos B/imunologia , Modelos Animais de Doenças , Melanoma Experimental/imunologia , Difosfato de Adenosina/farmacologia , Difosfato de Adenosina/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/metabolismo , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/metabolismoRESUMO
HMGA2 gene amplification and overexpression in human prolactinomas and the development of pituitary adenomas in HMGA2 transgenic mice showed that HMGA2 plays a crucial role in pituitary tumorigenesis. We have explored the pRB/E2F1 pathway to investigate the mechanism by which HMGA2 acts. Here we show that HMGA2 interacts with pRB and induces E2F1 activity in mouse pituitary adenomas by displacing HDAC1 from the pRB/E2F1 complex-a process that results in E2F1 acetylation. We found that loss of E2F1 function (obtained by mating HMGA2 and E2F1(-/-) mice) suppressed pituitary tumorigenesis in HMGA2 mice. Thus, HMGA2-mediated E2F1 activation is a crucial event in the onset of these tumors in transgenic mice and probably also in human prolactinomas.
Assuntos
Fator de Transcrição E2F1/fisiologia , Proteína HMGA2/fisiologia , Neoplasias Hipofisárias/metabolismo , Acetilação , Animais , Linhagem Celular , Proliferação de Células , Transformação Celular Neoplásica , DNA/metabolismo , Fator de Transcrição E2F1/genética , Ativação Enzimática , Proteína HMGA2/biossíntese , Proteína HMGA2/genética , Histona Desacetilase 1 , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Camundongos , Camundongos Knockout , Camundongos Mutantes , Camundongos Transgênicos , Neoplasias Hipofisárias/patologia , Regiões Promotoras Genéticas , Ligação Proteica , Elementos de Resposta , Proteína do Retinoblastoma/metabolismo , Transdução de SinaisRESUMO
The PATZ1 gene encoding a POZ/AT-hook/Kruppel zinc finger (PATZ) transcription factor, is considered a cancer-related gene because of its loss or misexpression in human neoplasias. As for other POZ/domain and Kruppel zinc finger (POK) family members, the transcriptional activity of PATZ is due to the POZ-mediated oligomer formation, suggesting that it might be not a typical transactivator but an architectural transcription factor, thus functioning either as activator or as repressor depending on the presence of proteins able to interact with it. Therefore, to better elucidate PATZ function, we searched for its molecular partners. By yeast two-hybrid screenings, we found a specific interaction between PATZ and BCL6, a human oncogene that plays a key role in germinal center (GC) derived neoplasias. We demonstrate that PATZ and BCL6 interact in germinal center-derived B lymphoma cells, through the POZ domain of PATZ. Moreover, we show that PATZ is able to bind the BCL6 regulatory region, where BCL6 itself acts as a negative regulator, and to contribute to negatively modulate its activity. Consistently, disruption of one or both Patz1 alleles in mice causes focal expansion of thymus B cells, in which BCL6 is up-regulated. This phenotype was almost completely rescued by crossing Patz1(+/-) with Bcl6(+/-) mice, indicating a key role for Bcl6 expression in its development. Finally, a significant number of Patz1 knock-out mice (both heterozygous and homozygous) also develop BCL6-expressing lymphomas. Therefore, the disruption of one or both Patz1 alleles may favor lymphomagenesis by activating the BCL6 pathway.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Repressoras/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Imunoprecipitação da Cromatina , Primers do DNA , Humanos , Linfoma de Células B/genética , Linfoma de Células B/patologia , Camundongos , Camundongos Knockout , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-6 , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Dendritic cells (DCs) are immunological sentinels of the organism acting as antigen-presenting cells (APC) and are critical for induction of innate and adaptive immunity. Traditionally they are divided in myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs), a rare population of circulating cells that selectively express Toll-like receptors (TLR) 7 and TLR9 and have the capacity to produce large amounts of type I interferons (IFNs) in response to pathogenic agents or danger signals. It has been demonstrated that pDCs can coordinate events during the course of viral infections, allergic and autoimmune diseases and cancer. Through the production of type I IFNs, pDCs initiate protective immunity by activating classical DCs, T cells, natural killer cells and B cells. Upon activation, pDCs also differentiate into mature DCs and may contribute to the contraction of T-cell response. Human pDCs preferentially express immunoglobulin-like transcript 7 (ILT7; LILRA4), which couples with a signaling adapter to activate a prominent immune-receptor tyrosine-based activation motif (ITAM)-mediated signaling pathway. The interaction between ILT7 and bone marrow stromal cell antigen 2 (BST2, CD317) assures an appropriate TLR response by pDCs during viral infections and likely participates in pDCs tumor crosstalk. Moreover these cells seem to play a crucial role in the initiation of the pathological process of autoimmune diseases such as lupus or psoriasis. Despite the fact that their function within a tumor context is still controversial they represent an attractive target for therapeutic manipulation of the immune system to elicit a powerful immune response against tumor antigens in combination with other therapies.
Assuntos
Células Dendríticas/fisiologia , Neoplasias/imunologia , Animais , Ensaios Clínicos como Assunto , Humanos , Neoplasias/terapia , Fenótipo , Receptores Imunológicos/fisiologia , Transdução de Sinais , Receptores Toll-Like/fisiologiaRESUMO
The ability of BAG3, a member of the BAG family of heat shock protein (Hsp) 70 - cochaperones, to sustain the survival of human primary B-CLL and ALL cells was recognized about nine years ago. Since then, the anti-apoptotic activity of BAG3 has been confirmed in other tumor types, where it has been shown to regulate the intracellular concentration and localization of apoptosis-regulating factors, including NF-κB-activating (IKKγ) and Bcl2-family (Bax) proteins. Furthermore, growing evidences support its role in lymphoid and myeloid leukemia response to therapy. Moreover in the last years, the contribution of BAG3 to autophagy, a process known to be involved in the pathogenesis and response to therapy of leukemia cells, has been disclosed, opening a new avenue for the interpretation of the role of this protein in leukemias' biology.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Leucemia/terapia , Proteínas Adaptadoras de Transdução de Sinal/análise , Proteínas Reguladoras de Apoptose , Autofagia , Sobrevivência Celular , Humanos , Leucemia/patologiaRESUMO
PATZ1 is an emerging cancer-related gene coding for a POZ/AT-hook/kruppel Zinc finger transcription factor, which is lost or misexpressed in human neoplasias. Here, we investigated its role in development exploring wild-type and Patz1-knockout mice during embryogenesis. We report that the Patz1 gene is ubiquitously expressed at early stages of development and becomes more restricted at later stages, with high levels of expression in actively proliferating neuroblasts belonging to the ventricular zones of the central nervous system (CNS). The analysis of embryos in which Patz1 was disrupted revealed the presence of severe defects in the CNS and in the cardiac outflow tract, which eventually lead to a pre-mature in utero death during late gestation or soon after birth. Moreover, the Patz1-null mice showed a general growth retardation, which was consistent with the slower growth rate and the increased susceptibility to senescence of Patz1(-/-) mouse embryonic fibroblasts (MEFs) compared to wild-type controls. Therefore, these results indicate a critical role of PATZ1 in the control of cell growth and embryonic development.
Assuntos
Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/genética , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Animais , Ciclo Celular/genética , Ciclo Celular/fisiologia , Sistema Nervoso Central/anormalidades , Sistema Nervoso Central/embriologia , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Feminino , Retardo do Crescimento Fetal/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Neoplasias/fisiologia , Fenótipo , Gravidez , Proteínas Repressoras/fisiologiaRESUMO
Tumor growth requires neoangiogenesis. VEGF is the most potent proangiogenic factor. Dysregulation of hypoxia-inducible factor (HIF) or cytokine stimuli such as those involving the chemokine receptor 4/stromal-derived cell factor 1 (CXCR4/SDF-1) axis are the major cause of ectopic overexpression of VEGF in tumors. Although the CXCR4/SDF-1 pathway is well characterized, the transcription factors executing the effector function of this signaling are poorly understood. The multifunctional Yin Yang 1 (YY1) protein is highly expressed in different types of cancers and may regulate some cancer-related genes. The network involving CXCR4/YY1 and neoangiogenesis could play a major role in cancer progression. In this study we have shown that YY1 forms an active complex with HIF-1alpha at VEGF gene promoters and increases VEGF transcription and expression observed by RT-PCR, ELISA, and Western blot using two different antibodies against VEGFB. Long-term treatment with T22 peptide (a CXCR4/SDF-1 inhibitor) and YY1 silencing can reduce in vivo systemic neoangiogenesis (P < 0.01 and P < 0.05 vs. control, respectively) during metastasis. Moreover, using an in vitro angiogenesis assay, we observed that YY1 silencing led to a 60% reduction in branches (P < 0.01) and tube length (P < 0.02) and a 75% reduction in tube area (P < 0.001) compared with control cells. A similar reduction was observed using T22 peptide. We demonstrated that T22 peptide determines YY1 cytoplasmic accumulation by reducing its phosphorylation via down-regulation of AKT, identifying a crosstalk mechanism involving CXCR4/YY1. Thus, YY1 may represent a crucial molecular target for antiangiogenic therapy during cancer progression.
Assuntos
Neoplasias/irrigação sanguínea , Neovascularização Patológica , Receptores CXCR4/antagonistas & inibidores , Fatores de Crescimento do Endotélio Vascular/genética , Fator de Transcrição YY1/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Transplante de Neoplasias , Neoplasias/metabolismo , Peptídeos/farmacologia , Ratos , Receptor Cross-Talk/fisiologia , Receptores CXCR4/metabolismo , Fatores de Transcrição , Transplante Heterólogo , Fator de Transcrição YY1/fisiologiaRESUMO
BAG3, a member of the BAG family of heat shock protein (HSP) 70 cochaperones, is expressed in response to stressful stimuli in a number of normal cell types and constitutively in a variety of tumors, including pancreas carcinomas, lymphocytic and myeloblastic leukemias, and thyroid carcinomas. Down-regulation of BAG3 results in cell death, but the underlying molecular mechanisms are still elusive. Here, we investigated the molecular mechanism of BAG3-dependent survival in human osteosarcoma (SAOS-2) and melanoma (M14) cells. We show that bag3 overexpression in tumors promotes survival through the NF-kappaB pathway. Indeed, we demonstrate that BAG3 alters the interaction between HSP70 and IKKgamma, increasing availability of IKKgamma and protecting it from proteasome-dependent degradation; this, in turn, results in increased NF-kappaB activity and survival. These results identify bag3 as a potential target for anticancer therapies in those tumors in which this gene is constitutively expressed. As a proof of principle, we show that treatment of a mouse xenograft tumor model with bag3siRNA-adenovirus that down-regulates bag3 results in reduced tumor growth and increased animal survival.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Regulação Neoplásica da Expressão Gênica , Quinase I-kappa B/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose , Proteínas Reguladoras de Apoptose , Linhagem Celular Tumoral , Feminino , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Biológicos , NF-kappa B/metabolismo , RNA Interferente Pequeno/metabolismoRESUMO
Non-small cell lung cancer (NSCLC), the leading cause of cancer death worldwide, is still an unmet medical problem due to the lack of both effective therapies against advanced stages and markers to allow a diagnosis of the disease at early stages before its progression. Immunotherapy targeting the PD-1/PD-L1 checkpoint is promising for many cancers, including NSCLC, but its success depends on the tumor expression of PD-L1. PATZ1 is an emerging cancer-related transcriptional regulator and diagnostic/prognostic biomarker in different malignant tumors, but its role in lung cancer is still obscure. Here we investigated expression and role of PATZ1 in NSCLC, in correlation with NSCLC subtypes and PD-L1 expression. A cohort of 104 NSCLCs, including lung squamous cell carcinomas (LUSCs) and adenocarcinomas (LUADs), was retrospectively analyzed by immunohistochemistry for the expression of PATZ1 and PD-L1. The results were correlated with each other and with the clinical characteristics, showing on the one hand a positive correlation between the high expression of PATZ1 and the LUSC subtype and, on the other hand, a negative correlation between PATZ1 and PD-L1, validated at the mRNA level in independent NSCLC datasets. Consistently, two NSCLC cell lines transfected with a PATZ1-overexpressing plasmid showed PD-L1 downregulation, suggesting a role for PATZ1 in the negative regulation of PD-L1. We also showed that PATZ1 overexpression inhibits NSCLC cell proliferation, migration, and invasion, and that Patz1-knockout mice develop LUAD. Overall, this suggests that PATZ1 may act as a tumor suppressor in NSCLC.