Advances in cancer vaccines for immunotherapy of prostate cancer / 中南大学学报(医学版)

Prostate cancer is currently one of the most common malignancies that endanger the lives and health of elderly men. In recent years, immunotherapy, which exploits the activation of anti-cancer host immune cells to accomplish tumor-killing effects, has emerged as a new study avenue in the treatment of prostate cancer. As an important component of immunotherapy, cancer vaccines have a unique position in the precision treatment of malignant tumors. Monocyte cell vaccines, dendritic cell vaccines, viral vaccines, peptide vaccines, and DNA/mRNA vaccines are the most often used prostate cancer vaccines. Among them, Sipuleucel-T, as a monocyte cell-based cancer vaccine, is the only FDA-approved therapeutic vaccine for prostate cancer, and has a unique position and role in advancing the development of immunotherapy for prostate cancer. However, due to its own limitations, Sipuleucel-T has not been widely adopted. Meanwhile, owing to the complexity of immunotherapy and the specificity of prostate cancer, the remaining prostate cancer vaccines have not shown good clinical benefit in large randomized phase II and phase III trials, and further in-depth studies are still needed.

Research Progress of Lung Cancer Vaccines / 中国肺癌杂志

With the development of medical technology, tumor vaccines as a novel precise immunotherapy approach have gradually received attention in clinical applications. Against the backdrop of the global corona virus disease 2019 (COVID-19) outbreak, vaccine technology has further advanced. Depending on the types of antigens, tumor vaccines can be divided into whole-cell vaccines, peptide vaccines, messenger ribonucleic acid (mRNA) vaccines, recombinant virus vaccines, etc. Although some tumor vaccines have been marketed and achieved certain therapeutic effects, the results of tumor vaccines in clinical trials have been unsatisfactory in the past period. With the maturation of next-generation sequencing (NGS) technology and the continuous development of bioinformatics, dynamic monitoring of the entire process of tumor subpopulation development has become a reality, which has laid a solid foundation for personalized, neoantigen-centered therapeutic tumor vaccines. This article reviews the recent developments of tumor vaccines of different types, starts with lung cancer and summarizes the achievements of tumor vaccines in clinical applications, and provides an outlook for the future development of antigen-centered tumor vaccines.
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Clinical research progress and implications of therapeutic vaccines for cervical cancer and precancerous lesions: a qualitative systematic review / 中华肿瘤杂志

Objective: To systematically summarize and analyze the clinical research progress of therapeutic vaccines for cervical cancer or precancerous lesions. Methods: English databases (PubMed, Embase, Web of Science, Cochrane library, Proquest, and ClinicalTrails.gov) and Chinese databases (SinoMed, CNKI, WanFang, and VIP Database) were systematically searched to collect literature on therapeutic vaccines for cervical cancer or precancerous lesions from inception to February 18, 2021. After screening, we evaluated the risk of bias of included studies, and combed the basic information of the literature, research designs, information of vaccines, study patients, outcome indicators and so on, qualitatively summarized the clinical research progress. Results: A total of 71 studies were included in this systematic review, including 14 random controlled trials, 15 quasi-random controlled trials, 4 cohort studies, 1 case-control study, 34 case series studies and 3 case reports. The study patients included women aged 15~79 with cervical cancer or precancerous lesions in 18 countries from 1989 to 2021. On the one hand, there were 40 studies on therapeutic vaccines for cervical precancerous lesions (22 867 participants), involving 21 kinds of vaccines in 6 categories. Results showed 3 marketed vaccines (Cervarix, Gardasil, Gardasil 9) as adjuvant immunotherapies were significant effective in preventing the recurrence of precancerous lesions compared with the conization only. In addition, MVA E2 vaccine had been in phase Ⅲ clinical trials as a specific therapeutic vaccine, with relative literature showing it could eliminate most high-grade precancerous lesions. Therapeutic vaccines for precancerous lesions all showed good safety. On the other hand, there were 31 studies on therapeutic vaccines for cervical cancer (781 participants), involving 19 kinds of vaccines in 7categories, with none had been marketed. 25 studies were with no control group, showing the vaccines could effectively eliminate solid tumors, prevent recurrence, and prolong the median survival time. However, the vaccines effectiveness couldn't be statistically calculated due to the lack of a control group. As for the safety of therapeutic vaccines for cervical cancer, 9 studies showed that patients experienced serious adverse events after treatments, where 7 studies reported that serious adverse events occurred in patients couldn't be ruled out as the results of therapeutic vaccines. Conclusions: The literature review shows that the literature evidence for the therapeutic vaccines for cervical precancerous lesions is relatively mature compared with the therapeutic vaccines for cervical cancer. The four kinds of vaccines on the market are all therapeutic vaccines for precancerous lesions, but they are generally used as vaginal infection treatments or adjuvant immunotherapies for cervical precancerous lesions, not used for the specific treatments of cervical precancerous lesions. Other specific therapeutic vaccines are in the early stage of clinical trials, mainly phase Ⅰ/Ⅱ clinical trials with small sample size. The effectiveness and safety data are limited, and further research is still needed.

Clinical Trial Progress and Application of Immune Checkpoint Inhibitors in the Treatment of Small Cell Lung Cancer / 中国肺癌杂志

Small cell lung cancer (SCLC) is a neuroendocrine tumor with fast progression, high malignancy, easy recurrence, and extremely poor prognosis. In the past 30 years, the clinical treatment strategy of SCLC has been mainly chemotherapy and radiotherapy, but the curative effect is not significant; the current immunotherapy of SCLC has gradually entered the clinic and has made certain progress. Tumor immunotherapy includes immune checkpoint inhibitors, tumor vaccines, cytokines, chimeric antigen receptor T-cell immunotherapy (CAR-T) therapy, etc. Currently, immune checkpoint inhibitors are the most widely used. This article summarizes the principles of immune checkpoint inhibitors and related drugs, summarizes their domestic and foreign clinical trials progress in SCLC treatment, reviews the biomarkers used in the therapy, and discusses its future development direction.
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LMP2-DC Vaccine Elicits Specific EBV-LMP2 Response to Effectively Improve Immunotherapy in Patients with Nasopharyngeal Cancer / 生物医学与环境科学（英文）

Objective@#To evaluate the safety and effectiveness of a vaccine based on latent membrane protein 2 (LMP2) modified dendritic cells (DCs) that boosts specific responses of cytotoxic T lymphocytes (CTLs) to LMP2 before and after intradermal injection in patients with nasopharyngeal carcinoma (NPC).@*Methods@#DCs were derived from peripheral blood monocytes of patients with NPC. We prepared LMP2-DCs infected by recombinant adenovirus vector expressing LMP2 (rAd-LMP2). NPC patients were immunized with 2 × 10 @*Results@#We demonstrated that DCs derived from monocytes displayed typical DC morphologies; the expression of LMP2 in the LMP2-DCs vaccine was confirmed by immunocytochemical assay. Twenty-nine patients with NPC were enrolled in this clinical trial. The LMP2-DCs vaccine was well tolerated in all of the patients. Boosted responses to LMP2 peptide sub-pools were observed in 18 of the 29 patients with NPC. The follow-up data of 29 immunized patients from April, 2010 to April 2015 indicated a five-year survival rate of 94.4% in responders and 45.5% in non-responders.@*Conclusion@#In this pilot study, we demonstrated that the LMP2-DCs vaccine is safe and effective in patients with NPC. Specific CTLs responses to LMP2 play a certain role in controlling and preventing the recurrence and metastasis of NPC, which warrants further clinical testing.

Uso de la vacuna CIMAvax-EGF® como práctica médica habitual / Use of the vaccine CIMAvax-EGF® as habitual medical practice

Se realizó un estudio descriptivo y longitudinal de 58 pacientes con cáncer de pulmón de células no pequeñas, atendidos en la consulta de Sombras Pulmonares correspondiente al Servicio de Neumología del Hospital General Docente Dr Juan Bruno Zayas Alfonso de Santiago de Cuba, desde enero del 2013 hasta igual mes del 2018, quienes eran tratados con CIMAvax-EGF® como práctica médica habitual, con vistas a determinar las características clinicoepidemiológicas de estos. En la serie primaron el sexo masculino y las edades de 60 a 79 años; asimismo, resultaron más frecuentes la etapa IV de la enfermedad y el adenocarcinoma como variedad histológica. Con el uso de la vacuna la mayoría de los pacientes presentaron una supervivencia de 12,9 meses y una respuesta terapéutica de enfermedad no progresora

A descriptive and longitudinal study of 58 patients with lung cancer of non small cells, assisted in the service of Lung Shades corresponding to the Pneumology Service of Dr Juan Bruno Zayas Alfonso Teaching General Hospital was carried out in Santiago de Cuba, from January, 2013 to the same month of 2018, who were treated with CIMAvax-EGF® as habitual medical practice, with the aim of determining the clinical and epidemiological characteristics of them. The male sex and ages from 60 to 79 years prevailed in the series; also, stage IV of the disease and the adenocarcinoma as histological variety were more frequent. With the use of the vaccine most of the patients presented a survival of 12.9 months and a therapeutic response of the non progressive disease

Immunological-based approaches for cancer therapy

The immunologic landscape of tumors has been continuously unveiled, providing a new look at the interactions between cancer cells and the immune system. Emerging tumor cells are constantly eliminated by the immune system, but some cells establish a long-term equilibrium phase leading to tumor immunoediting and, eventually, evasion. During this process, tumor cells tend to acquire more mutations. Bearing a high mutation burden leads to a greater number of neoantigens with the potential to initiate an immune response. Although many tumors evoke an immune response, tumor clearance by the immune system does not occur due to a suppressive tumor microenvironment. The mechanisms by which tumors achieve the ability to evade immunologic control vary. Understanding these differences is crucial for the improvement and application of new immune-based therapies. Much effort has been placed in developing in silico algorithms to predict tumor immunogenicity and to characterize the microenvironment via high-throughput sequencing and gene expression techniques. Each sequencing source, transcriptomics, and genomics yields a distinct level of data, helping to elucidate the tumor-based immune responses and guiding the fine-tuning of current and upcoming immune-based therapies. In this review, we explore some of the immunological concepts behind the new immunotherapies and the bioinformatic tools to study the immunological aspects of tumors, focusing on neoantigen determination and microenvironment deconvolution. We further discuss the immune-based therapies already in clinical use, those underway for future clinical application, the next steps in immunotherapy, and how the characterization of the tumor immune contexture can impact therapies aiming to promote or unleash immune-based tumor elimination.

Perspectives on the clinical development of immunotherapy in prostate cancer / 亚洲男科学杂志(英文版)

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. Sipuleucel-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. Reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomarkers, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.

Construction of a fusion plasmid containing the PSCA gene and cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) and its anti-tumor effect in an animal model of prostate cancer

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is a negative regulator of T cell activation, which competes with CD28 for B7.1/B7.2 binding, and which has a greater affinity. Fusion of specific antigens to extracellular domain of CTLA4 represents a promising approach to increase the immunogenicity of DNA vaccines. In this study, we evaluated this interesting approach for CTLA4 enhancement on prostate stem cell antigen (PSCA)-specific immune responses and its anti-tumor effects in a prostate cancer mouse model. Consequently, we constructed a DNA vaccine containing the PSCA and the CTLA-4 gene. Vaccination with the CTLA4-fused DNA not only induced a much higher level of anti-PSCA antibody, but also increased PSCA-specific T cell response in mice. To evaluate the anti-tumor efficacy of the plasmids, murine models with PSCA-expressing tumors were generated. After injection of the tumor-bearing mouse model, the plasmid carrying the CTLA4 and PSCA fusion gene showed stronger inhibition of tumor growth than the plasmid expressing PSCA alone. These observations emphasize the potential of the CTLA4-fused DNA vaccine, which could represent a promising approach for tumor immunotherapy.

Experiencia en enfermería, ensayo clínico y atención a pacientes con cáncer de pulmón / Experience in nursing, clinical assay and care of patients with lung cancer

INTRODUCCIÓN: los ensayos clínicos con nuevas sustancias, como anticuerpos y vacunas han tenido un incremento debido a la necesidad de encontrar nuevas terapéuticas para el tratamiento del cáncer. En la aplicación del tratamiento el éxito depende del buen desempeño profesional, el nivel de preparación y capacitación que tenga el personal de enfermería, como parte del equipo de investigación al ejecutar un rol importante. OBJETIVO: evaluar la experiencia del personal de enfermería en este ensayo relacionado con la atención a pacientes con cáncer de pulmón. MÉTODOS: se realizó un estudio descriptivo con una revisión bibliográfica sobre el actuar, y la experiencia de enfermería en el ensayo clínico. Se evaluó la seguridad de CIMAvax®- EGF en pacientes avanzados con tumores del pulmón, de células no pequeñas y tratados en la asistencia primaria de salud. Para ello se realizó un análisis documental de la buena práctica clínica, y los protocolos de estudios sobre el tema. RESULTADOS: fueron incluidos 11 pacientes. El promedio de diagnóstico y tratamiento de pacientes, con cáncer de pulmón estuvo en 23 y 14 meses al respecto. CONCLUSIONES: enfermero (a) en su desempeño debe tener dominio del protocolo en su totalidad sobre el producto, propiedades farmacéuticas y dosis a administrar. Además, identificar las reacciones adversas que pueden presentarse y las medidas a tomar para de esta forma lograr evaluar la efectividad del nuevo producto en investigación y mitigar cualquier riesgo que influya en la calidad y excelencia de nuestros servicios de salud.

INTRODUCTION: an increase in clinical assays of new substances, such as antibodies and vaccines, has taken place in response to the need to find new cancer therapies. Success in the application of treatment depends on the good professional performance, background and training of nursing personnel, for they play an important role as research team members. OBJECTIVE: evaluate the experience of nursing personnel in an assay about the care of patients with lung cancer. METHODS: a descriptive study was conducted based on a bibliographic review of the role and experience of nurses in the clinical assay performed. The safety of CIMAvax®- EGF was evaluated in patients with advanced non-small-cell lung tumors treated at primary health care services. For this purpose a document analysis was performed about good clinical practice and study protocols about the subject. RESULTS: eleven patients were included. Average diagnosis and treatment of patients with lung cancer was 23 and 14 months, respectively. CONCLUSIONS: nurses should be thoroughly aware of the entire protocol, particularly the product, its pharmaceutical properties and the dose to administer. They should also be able to identify the potential adverse reactions and the measures to take to assess the effectiveness of the new product under research, as well as mitigate any risk affecting the quality and excellence of our health services.

Efectos del bloqueo del sistema EGF/EGFR sobre la cicatrización de las heridas en pacientes oncológicos / Effects of the blockade of EGF/EGFR system on wound healing cancer patients

La administración de drogas que bloquean el sistema del factor de crecimiento epidérmico y su receptor ha demostrado efectos beneficiosos en pacientes con tumores sólidos de origen epitelial. Cada día resulta más frecuente el uso de múltiples modalidades terapéuticas para combatir estos tumores, las cuales incluyen la asociación de agentes blanco y cirugía. Los agentes que actúan sobre dicho sistema pudieran causar trastornos de la cicatrización al bloquear vías del sistema que también intervienen en la cicatrización de las heridas. El objetivo de este artículo es revisar y comentar acerca del conocimiento de la relación entre el uso de las drogas anti-EGF/EGFR y los trastornos en la cicatrización de las heridas. La búsqueda bibliográfica se realizó en PubMed y Google (solo en español e inglés) y se tuvo en cuenta cualquier publicación encontrada hasta enero del 2014. Se incluyeron los anticuerpos monoclonales cetuximab, panitumumab y nimotuzumab; las pequeñas moléculas erlotinib y gefitinib y las vacunas terapéuticas contra el cáncer CIMAvax EGF y HER-1. Se hace especial énfasis en los biofarmacéuticos nimotuzumab, CIMAvax EGF y HER-1; producidos en el Centro de Inmunología Molecular, La Habana, Cuba, debido a su amplio uso en Cuba y otros países de América Latina. No se encontraron evidencias de relación entre el uso de estos productos y la aparición de trastornos en la cicatrización de las heridas. Dado que los tratamientos anti-EGF/EGFR también inhiben la proliferación celular que induce el drenaje de las heridas y la migración celular inducida por las radiaciones, se sugiere que el tratamiento anti-EGF/EGFR no debe suspenderse, ni antes ni después de la cirugía y sus posibles efectos deben ser vigilados. Obviamente, se necesitan ulteriores investigaciones por parte de los farmacólogos no clínicos y clínicos, oncólogos clínicos y cirujanos oncológicos para entender mejor los procesos fisiopatológicos de cicatrización en los cánceres de origen epitelial(AU)

The use of blocking drugs for epidermal growth factor and its receptor system has shown beneficial effects in patients with solid tumors of epithelial origin. It is increasingly common to use a multi-modal treatment approach towards solid tumors, often including the association of target agents and surgical resection. Some target agents can impair wound healing or cause increasing risk of perioperative complications if they block system pathways that may intervene in wound healing. The objective of this paper was to review and comment on the existing knowledge about the relationship between the use of anti-EGF/EGFR drugs and the disorders in wound healing. Citations from PubMed and Google (English and Spanish languages only) regardless of the date of publication were reviewed to identify potentially useful articles until January 2014. Monoclonal antibodies cetuximab, panitumumab, nimotuzumab; the small molecules erlotinib and gefitinib, and the therapeutic cancer vaccines called CIMAvax EGF and HER-1. Special emphasis was made on biopharmaceuticals nimotuzumab, CIMAvax EGF and HER-1, all of them produced at the Center of Molecular Immunology, Havana, Cuba, because of their extensive use in Cuba and many Latin-American countries. No evidence of association between the use of these products and the occurrence of complications in wound healing was found. Given that the anti-EGF/EGFR treatments also inhibit the tumor cell proliferation that wound drainage induces and the radiation-induced cell migration, it is suggested that that the administration of this kind of drugs should be kept before and after the surgery and consequently, its possible effects must be under surveillance. Obviously, non-clinical and clinical pharmacologists, clinical oncologists and surgeons need further researches for better understanding the pathophysiological wound healing processes in epithelial cancers(AU)

Glioma Stem Cell-Targeted Dendritic Cells as a Tumor Vaccine Against Malignant Glioma

PURPOSE: Cancer stem cells have recently been thought to be closely related to tumor development and reoccurrence. It may be a promising way to cure malignant glioma by using glioma stem cell-targeted dendritic cells as a tumor vaccine. In this study, we explored whether pulsing dendritic cells with antigens of glioma stem cells was a potent way to induce specific cytotoxic T lymphocytes and anti-tumor immunity. MATERIALS AND METHODS: Cancer stem cells were cultured from glioma cell line U251. Lysate of glioma stem cells was obtained by the repeated freezing and thawing method. Dendritic cells (DCs) were induced and cultured from the murine bone marrow cells, the biological characteristics were detected by electron microscope and flow cytometry. The DC vaccine was obtained by mixing DCs with lysate of glioma stem cells. The DC vaccine was charactirizated through the mixed lymphocyte responses and cell killing experiment in vitro. Level of interferon-gamma (IFN-gamma) in the supernatant was checked by ELISA. RESULTS: After stimulation of lysate of glioma stem cell, expression of surface molecules of DC was up-regulated, including CD80, CD86, CD11C and MHC-II. DCs pulsed with lysate of glioma stem cells were more effective than the control group in stimulating original glioma cells-specific cytotoxic T lymphocytes responses, killing glioma cells and boosting the secretion of IFN-gamma in vitro. CONCLUSION: The results demonstrated DCs loaded with antigens derived from glioma stem cells can effectively stimulate naive T cells to form specific cytotoxic T cells, kill glioma cells cultured in vitro.

The Mycobacterium avium subsp. paratuberculosis fibronectin attachment protein, a toll-like receptor 4 agonist, enhances dendritic cell-based cancer vaccine potency

In this study, we showed the direct interaction between Mycobacterium avium subsp. paratuberculosis fibronectin attachment protein (FAP) and toll-like receptor4 (TLR4) via co-localization and binding by using confocal microscopy and co-immunoprecipitation assays. FAP triggered the expression of pro- and anti-inflammatory cytokines in a TLR4-dependent manner. In addition, FAP-induced cytokine expression in bone marrow-derived dendritic cells (BMDCs) was modulated in part by glycogen synthase kinase-3 (GSK-3). FAP-induced expression of CD80, CD86, major histocompatibility complex (MHC) class I, and MHC class II in TLR4+/+ BMDCs was not observed in TLR4-/- BMDCs. Furthermore, FAP induced DC-mediated CD8+ T cell proliferation and cytotoxic T lymphocyte (CTL) activity, and suppressed tumor growth with DC-based tumor vaccination in EG7 thymoma murine model. Taken together, these results indicate that the TLR4 agonist, FAP, a potential immunoadjuvant for DC-based cancer vaccination, improves the DC-based immune response via the TLR4 signaling pathway.

Early experience with targeted therapy and dendritic cell vaccine in metastatic renal cell carcinoma after nephrectomy

PURPOSE: Metastatic renal cell carcinoma (RCC) is one of the most treatment-resistant malignancies and nephrectomy, isolated or combined with systemic chemotherapy typically has limited or no effectiveness. We report our initial results in patients treated with the association of molecular targeted therapy, nephrectomy, and hybrid dendritic-tumor cell (DC) vaccine. MATERIALS AND METHODS: Two male patients diagnosed with metastatic RCC were selected for the study. They were treated with the triple strategy, in which sunitinib (50 mg per day) was given for 4 weeks, followed by radical nephrectomy after two weeks. DC vaccine was initiated immediately after surgery and repeated monthly. Sunitinib was restarted daily after 2 to 3 weeks of surgery with a 7-day interval every 4 weeks. RESULTS: Both patients had complete adherence to the proposed treatment with DC vaccine therapy combined with sunitinib. Follow-up in these patients at 9 and 10 months demonstrated a stable disease in both, as shown by imaging and clinical findings, with no further treatment required. CONCLUSION: The immune response obtained with DC vaccine combined with the antiangiogenic effect of sunitinib and the potential benefits of cytoreductive nephrectomy in advanced disease could represent a new option in the treatment of metastatic RCC. Further prospective trials are needed not only to elucidate the ideal dosing and schedule, but also to better define the proof-of-concept proposed in this report and its role in clinical practice.

Vacuna contra el virus del papiloma humano (VPH) / Vaccine against human papilloma virus (HPV)

El cáncer cuello uterino es el segundo más frecuente en mujeres en el mundo, y constituye una importante causa de mortalidad en nuestro país. La infección con el virus del papiloma humano es reconocida como un co-factor necesario para la génesis de este cáncer. La integración del genoma viral al genoma de la célula huésped altera el ciclo celular normal, favoreciendo su transformación neoplásica. El avance en comprensión de esta relación virus-huésped ha conducido a diseñar una vacuna, cuyo objetivo final sería erradicar esta enfermedad. Este artículo da una perspectiva global del problema y una revisión del conocimiento actual respecto a la vacuna, recientemente implementada en nuestro país.

Dendritic cells and antigen trapping technology--a revolution in vaccine/immunotherapy strategy.

Vaccines based on dendritic cells--the immune system's key responders to foreign invaders--grabbed the spotlight of this decade. Scientists have devised a dozen different ways to make dendritic cell vaccines. They have linked dendritic cells with all kinds of antigens, including peptides derived from gene mutations, tumor/pathogen RNA, viral vectors, and with whole pathogen/tumor lysate. And they are adding cytokines such as granulocyte macrophage colony stimulating factor or interleukin 4 during dendritic cell growth or maturation or at the site of vaccination to try to boost response. We are still learning the best way to generate the dendritic cells, load them with the antigen and send them to the right place in the body, and use of the biological stage of development of dendritic cells that is best suited to stimulate a response. In the present review attempts have been made to present a comprehensive synopsis of the history, development and ramifications of evolving knowledge on dendritic cell biology and the prospects for being developed as a rational immunotherapeutic tool. Further clinical studies are warranted.

Reversión del eclipse inmunológico y vacunación terapéutica contra el cáncer en un modelo experimental / Reversion of the immunological eclipse and therapeutic vaccination against cancer in an experimental model

Aunque existen vacunas para prevenir la aparición de tumores en animales de experimentación, la mayoría de los intentos por aplicar aquellas vacunas con fines terapéuticos contra tumores establecidos no han sido exitosos. Para comprender la naturaleza de esta refractariedad, estudiamos un tumor de ratón fuertemente inmunogénico inducido por el carcinógeno químico metilcolantreno. En nuestro modelo, el inicio de esta refractariedad coincidió con el comienzo de un estado de inmunosupresión conocido como "eclipse inmunológico" caracterizado por una pérdida o bloqueo de la respuesta inmune antitumoral después que el tumor ha superado cierto tamaño crítico. Este eclipse inmunológico fue acompañado por un proceso de inflamación sistémica en el organismo. El tratamiento de los ratones portadores de tumor con una única dosis del corticoide sintético dexametasona (DX) redujo los parámetros de inflamación sistémica e indujo la reversión del eclipse. Esta reversión no fue por sí misma curativa pero permitió que un tratamiento inmunológico basado en células dendríticas estimuladas con antígenos tumorales, que por sí solo era absolutamente ineficaz, pudiera ejercer un significativo efecto inhibidor sobre un tumor en crecimiento. El esquema de dos pasos que comprende, primero, un tratamiento antiinflamatorio para revertir el eclipse y segundo, una estrategia de vacunación basada en células dendríticas destinada a estimular la respuesta inmune antitumoral, podría servir, eventualmente, como un modelo de inmunoterapia contra tumores en animales y seres humanos.

Although animals can be prophylactically immunized against the growth of tumor implants, most of the attempts to use immunotherapy to cause the regression of animal and human tumors once they become established have been unsuccessful. To understand the nature of this refractoriness we have studied a methylcholanthrene-induced and strongly immunogenic murine fibrosarcoma. In our model, the onset of this refractoriness was associated with the beginning of an immunosuppressive state known as "immunological eclipse" characterized by a loss of the antitumor immune response when tumor grows beyond a critical size. This immunological eclipse was accompanied by the emergence of a systemic inflammatory condition. Treatment of tumor-bearing mice with a single dose of a synthetic corticosteroid, dexamethasone (DX), reduced significantly all parameters of systemic inflammation and simultaneously reversed the immunological eclipse. The reversion of the eclipse upon DX treatment was not curative itself, but allowed an immunological therapy based in dendritic cells pulsed with tumor antigens, which was itself absolutely ineffective, to exert a significant inhibitory effect against an established growing tumor. The two-step schedule using an anti-inflammatory treatment to reverse the immunological eclipse plus a dendritic cell-based vaccination strategy aimed to stimulate the anti-tumor immune response, could serve eventually as a model of immunotherapy against animal and human tumors.

Pure sarcomatous recurrence of clear cell renal carcinoma following radical nephrectomy and dendritic cell vaccination / Recorrência sarcomatosa pura após nefrectomia radical e vacina de células dendríticas no carcinoma renal de células claras

CONTEXT: Sarcomatous differentiation, which represents transformation to high-grade malignancy, can occur in all histogical types of renal malignancy. CASE REPORT: The authors report on the case of a 66-year-old woman with a right renal mass that was shown to be a clear cell carcinoma. She underwent radical nephrectomy and dendritic cell vaccination and, 3.5 years later, she developed retroperitoneal pure sarcomatous recurrence of the tumor. The authors speculate that the vaccination could have played some role in this differentiation or selection of the sarcomatous component of the primary tumor.

CONTEXTO: Diferenciação sarcomatosa, que representa evolução para malignidade de alto grau, pode ocorrer em todos os tipos histológicos de câncer renal. RELATO DE CASO: Os autores relatam o caso de uma mulher de 66 anos, com uma massa no rim esquerdo que se revelou um carcinoma de células renais. Após 3,5 anos da nefrectomia radical seguida de vacinação com células dendríticas, a paciente desenvolveu uma recorrência sarcomatosa pura no retroperitônio. Os autores especulam que a terapia com vacina de células dendríticas pode ter desempenhado algum papel na diferenciação ou seleção do componente sarcomatoso do tumor primário.

El antígeno carcinoembrionario: a propósito de un viejo conocido / The carcinoembryonic antigen: by the way a well-known friend

The carcinoembryonic antigen (CEA) is glycoprotein localized in the apical surface of mature enterocytes. The members of the CEA gene family are clustered on chromosome 19q13.2. It is formed by 29 genes, of which 18 are expressed. Many functions of CEA have been known in healthy individuals, however its role as cell adhesion molecule is the most studied. Besides the colon, CEA is expressed in the stomach, tongue, oesophagus, cervix, and prostate. The most important clinical function is in colorectal, gastric and ovary cancer. It is used as prognosis marker, staging system, recurrence, treatment response and liver metastases. There are many no neoplasic-diseases that enhance CEA value. Actually, the CEA is being studying as target of immunotherapy.

El antígeno carcinoembrionario (ACE) es una glucoproteína localizada en el polo apical de los enterocitos. Los genes que codifican para el ACE se localizan en el cromosoma 19q13.2. El grupo total está constituido por 29 genes, divididos en tres subgrupos de los cuales se expresan sólo 18. En el individuo sano existen múltiples funciones del ACE que han sido ampliamente estudiadas, su función como molécula de adhesión ha sido la más ampliamente difundida. En pacientes sanos además de expresarse a nivel de colon el ACE se expresa en células de la lengua, esófago, estómago, cervix y próstata. Los pacientes que reciben una mayor utilidad clínica son aquellos con cáncer colorrectal (CCR), cáncer gástrico y cáncer de ovario. Su uso más amplio es en el CCR, actualmente se utiliza como marcador pronóstico, estadiaje, marcador de recurrencia, de respuesta al tratamiento y como indicador de metástasis a nivel hepático. Existen algunas patologías no neoplásicas que causan elevación de las cifras séricas de ACE. Actualmente se estudia al ACE como blanco de inmunoterapia dirigida a tumores que contengan células que expresen esta molécula.

Biologic Therapy for Brain Cancers - Based on Cellular and Immunobiology

The overall goal of our research projects is to develop effective immunotherapeutic regimens, particularly combining vaccine and gene therapy/ cell therapy strategies. For the development of clinically effective immunotherapy for brain cancers, the following issues are considered to be particularly important: 1) Induction of effective immune responses against tumors (afferent arm of the immune response), 2) Delivery of immune effector cells to the target tumor sites and maintaining the activity of the effector cells (efferent arm), 3) For specific and safe immunotherapy, specific brain tumor rejection antigens have to be identified, 4) Feasibility, safety and efficacy need to be tested in a series of clinical trials. The following presentation summarizes my research projects and demonstrates how each plan will fit in the whole schema of designing successful immunotherapeutic strategies for brain cancers. In this presentation, I would like to focus on our clinical and basic studies related to the vaccine strategies for patients with glioma, and modulation of tumor-microenvironment using bone-marrow derived stroma cells as vehicles for cytokine- gene delivery.