CHRISTIAN ALBERT MERKEL
Projetos de Pesquisa
Unidades Organizacionais
SVMULTI-05, Faculdade de Medicina
4 resultados
Resultados de Busca
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- Combined p19Arf and interferon-beta gene transfer enhances cell death of B16 melanoma in vitro and in vivo(2013) MERKEL, C. A.; MEDRANO, R. F. V.; BARAUNA, V. G.; STRAUSS, B. E.Approximately 90% of melanomas retain wild-type p53, a characteristic that may help shape the development of novel treatment strategies. Here, we employed an adenoviral vector where transgene expression is,controlled by p53 to deliver the p19 alternate reading frame (An) and interferon-beta (IFN beta) complementary DNAs in the B16 mouse model of melanoma. In vitro, cell death was enhanced by combined gene transfer (63.82 +/- 15.30% sub-GO cells); yet introduction of a single gene resulted in significantly fewer hypoploid cells (37.73 +/- 7.3% or 36.96 +/- 11.58%, p19Arf or IFN beta, respectively, P < 0.05). Annexin V staining and caspase-3 cleavage indicate a cell death mechanism consistent with apoptosis. Using reverse transcriptase quantitative PCR, we show that key transcriptional targets of p53 were upregulated in the presence of p19Arf, although treatment with IFN beta did not alter expression of the genes studied. In situ gene therapy revealed significant inhibition of subcutaneous tumors by IFN beta (571 +/- 25 mm(3)) or the combination of p19Arf and IFN beta (489 +/- 124 mm(3)) as compared with the LacZ control (1875 +/- 33 mm(3), P < 0.001); whereas p19Arf yielded an intermediate result (1053 +/- 169 mm(3), P < 0.01 vs control). However, only the combination was associated with increased cell death and prolonged survival (P < 0.01). As shown here, the combined transfer of p19Arf and IFN beta using p53-responsive vectors enhanced cell death both in vitro and in vivo.
conferenceObject Combined p19Arf and Interferon-beta Gene Therapy: Evidence of Immune Response in Murine Models of Melanoma and Lung Carcinoma(2013) STRAUSS, Bryan E.; MEDRANO, Ruan Felipe V.; RIBEIRO, Aline H.; CATANI, Joao Paulo P.; MERKEL, Christian A.Background: Our previous work has included the development of viral vectors where transgene expression is controlled by the transcriptional functions of the p53 tumor suppressor protein. Since wild-type p53 is frequently maintained in melanoma, we propose that such vectors may provide an opportunity for interplay between endogenous and exogenous factors. Transfer of p19Arf, a functional partner of p53, should help activate endogenous p53, thus supporting both vector expression and killing of tumor cells. Interferon-beta (IFNβ) is known to activate the immune system, induce apoptosis and inhibit angiogenesis. Moreover, interactions of the p53/Arf and IFN pathways have been reported. Previously we have shown that combined, but not individual, transfer of p19Arf and IFNβ mediated by our p53-responsive Ad5 vector induced massive cell death of B16 (mouse melanoma) both in vitro and in vivo. Objective: Our current aims include revealing involvement of the immune system in response to gene transfer protocols utilizing p53-responsive Ad5 or AdRGD vectors. Methods/Results: B16 cells with forced expression of CAR were transduced ex vivo with the Ad5 vectors (called AdPG) and implanted subcutaneously in C57BL/6 mice. Seven days later, these same mice received a challenge with fresh B16 cells implanted s.c. in the contralateral flank. Transfer of IFNβ alone or in combination with p19Arf reduced tumor formation at the sites of the vaccination and challenge. However, the combined treatment resulted in smaller tumors with delayed progression and prolonged survival. In parallel, RGD-modified adenoviral vectors, AdRGDPG, were constructed and shown to increase viral tropism as well as provide the expected synergy between p19Arf and IFNβ in CAR-negative B16 cells. This new set of AdRGDPG vectors was used in a model of in situ gene therapy of Lewis Lung Carcinoma (LLC) where tumors were first established s.c. in C57BL/6 mice then treated in vivo with six rounds of viral transduction. Treatment with IFNβ alone or in combination with p19Arf was effective in retarding tumor progression. Strikingly, s.c. challenge tumors implanted in the contralateral flank were inhibited especially well only in the animals previously treated with the combination of p19Arf and IFNβ. Alternatively, LLC cells were implanted s.c. in Balb/c nude mice and treated in situ. In this case, we did not observe a reduction in tumor progression in any of the conditions, indicating the importance of the adaptive immune system for tumor inhibition in response to our gene transfer strategy. Conclusion: In mouse tumor cell lines that retain wild-type p53, treatment with the combination of p19 Arf and IFNβ appears to involve the immune system, induce immunological memory and may provide an advantage over mono-gene therapy.- Vaccination using melanoma cells treated with p19arf and interferon beta gene transfer in a mouse model: a novel combination for cancer immunotherapy(2016) MEDRANO, Ruan Felipe Vieira; CATANI, Joao Paulo Portela; RIBEIRO, Aline Hunger; TOMAZ, Samanta Lopes; MERKEL, Christian A.; COSTANZI-STRAUSS, Eugenia; STRAUSS, Bryan E.Previously, we combined p19(Arf) (Cdkn2a, tumor suppressor protein) and interferon beta (IFN-beta, immunomodulatory cytokine) gene transfer in order to enhance cell death in a murine model of melanoma. Here, we present evidence of the immune response induced when B16 cells succumbing to death due to treatment with p19(Arf) and IFN-beta are applied in vaccine models. Use of dying cells for prophylactic vaccination was investigated, identifying conditions for tumor-free survival. After combined p19(Arf) and IFN-beta treatment, we observed immune rejection at the vaccine site in immune competent and nude mice with normal NK activity, but not in NOD-SCID and dexamethasone immunosuppressed mice (NK deficient). Combined treatment induced IL-15, ULBP1, FAS/APO1 and KILLER/DR5 expression, providing a mechanism for NK activation. Prophylactic vaccination protected against tumor challenge, where markedly delayed progression and leukocyte infiltration were observed. Analysis of primed lymphocytes revealed secretion of TH1-related cytokines and depletion protocols showed that both CD4(+) and CD8(+) T lymphocytes are necessary for immune protection. However, application of this prophylactic vaccine where cells were treated either with IFN-beta alone or combined with p19(Arf) conferred similar immune protection and cytokine activation, yet only the combination was associated with increased overall survival. In a therapeutic vaccine protocol, only the combination was associated with reduced tumor progression. Our results indicate that by harnessing cell death in an immunogenic context, our p19(Arf) and IFN-beta combination offers a clear advantage when both genes are included in the vaccine and warrants further development as a novel immunotherapy for melanoma.
- Reestablishment of p53/Arf and interferon-beta pathways mediated by a novel adenoviral vector potentiates antiviral response and immunogenic cell death(2017) HUNGER, Aline; V, Ruan F. Medrano; ZANATTA, Daniela B.; VALLE, Paulo R. Del; MERKEL, Christian A.; SALLES, Thiago de Almeida; FERRARI, Daniel G.; FURUYA, Tatiane K.; BUSTOS, Silvina O.; SAITO, Renata de Freitas; COSTANZI-STRAUSS, Eugenia; STRAUSS, Bryan E.Late stage melanoma continues to be quite difficult to treat and new therapeutic approaches are needed. Since these tumors often retain wild-type p53 and have a strong immunogenic potential, we developed a gene transfer approach which targets these characteristics. Previously, we have shown that combined gene transfer of p19Arf and interferon-beta (IFN beta) results in higher levels of cell death and superior immune-mediated antitumor protection. However, these experiments were performed using B16 cells (p53wt) with forced expression of the adenovirus receptor and also the mechanism of death was largely unexplored. Here we take advantage of a novel adenoviral vector (AdRGD-PG), presenting an RGD-modified fiber as well as a p53-responsive promoter, in order to investigate further potential benefits and cell death mechanisms involved with the combined transfer of the p19Arf and IFN beta genes to the parental B16 cell line. Simultaneous p19Arf and IFN beta gene transfer is more effective for the induction of cell death than single gene treatment and we revealed that p19Arf can sensitize cells to the bystander effect mediated by secreted IFN beta. Strikingly, the levels of cell death induced upon activating the p53/p19Arf and interferon pathways were higher in the presence of the AdRGD-PG vectors as compared to approaches using pharmacological mimetics and this was accompanied by the upregulation of antiviral response genes. Only combined gene transfer conferred immunogenic cell death revealed by the detection of key markers both in vitro and in vivo. Finally, whole-genome transcriptome analysis revealed unique expression profiles depending on gene function, including immune activation, response to virus and p53 signaling. In this way, cooperation of p19Arf and IFN beta activates the p53 pathway in the presence of an antiviral response elicited by IFN beta , culminating in immunogenic cell death.