[Idiotype vaccines in the treatment of follicular lymphoma: current status and future perspectives]. / Vacuna idiotípica en el tratamiento del linfoma folicular: situación actual y perspectivas futuras.

Follicular lymphoma is the second most prevalent non-Hodgkin lymphoma, representing 20% of all lymphomas. Follicular lymphoma is an indolent disease with a slow progression in which, although exhibiting a good response to treatment, relapse is very frequent and complete remission is not easy to maintain. Therefore, the disease is regarded as incurable. The search for new therapeutic strategies, together with a better understanding of the immune system, has led to the emergence of a new treatment named immunotherapy. Follicular lymphoma is a malignancy suitable for this kind of treatment given the fact that it is characterized by presenting a unique tumour-specific antigen: the idiotype of the monoclonal immunoglobulin displayed on the membrane of tumour cells. Several studies have been conducted to test immunotherapy as complementary to conventional treatment. In a previous study by our group, a clear benefit was evident is obtained after idiotypic vaccination, when an adequate immunization of the patient is obtained, in comparison to chemotherapy alone. In this sense, analysis is needed of whether idiotypic vaccination can produce not only long-lasting and complete remission, but even cure. It would be of great interest to consider an optimisation of the experimental design of clinical trials, an improvement of vaccine production, and the study of the molecular mechanisms of the tumour cell which modify the target immunoglobulin.

Anti-idiotype antibodies in cancer treatment.

As a cancer immunotherapy tool, idiotypes (Ids) have been used in different ways over the last three decades, depending on the actual human tumor cell target. It all started with passive, monoclonal, anti-Id antibody treatment of B-cell lymphoma, a setting in which results were tantalizing, but logistics unsustainable. It then moved toward the development of anti-Id vaccines for the treatment of the same tumors, a setting in which we have recently provided the first formal proof of principle of clinical benefit associated with the use of a human cancer vaccine. Meanwhile, it also expanded in the direction of exploiting the antigenic mimicry of some Ids with Id-unrelated, tumor-associated antigens for the immunotherapy of a number of solid tumors, a setting in which clinical results are still far from being consolidated. All in all, over the years Id-based immunotherapy has paved the way for a number of seminal therapeutic improvements for cancer patients, including the development of most if not all Id-unrelated monoclonal antibodies that have recently revolutionized the field.

Structure-based assessment of BRCA1 and BRCA2 mutations in a small Spanish population.

Breast cancer is the most frequent cancer type among women in the world. There is abundant evidence, that alterations in the breast cancer susceptibility genes, BRCA1 and BRCA2, are present in a large proportion of families with multiple cases of breast and ovarian cancer. Our aim was to better understand the molecular and structural insights associated with the most frequent alterations, found in the BRCA1 and BRCA2 genes, within our patients. We analyzed 50 breast cancer cases. Of those, 24% were found to carry deleterious mutations, and up to 10 rare variants of unknown significance were detected. The frequency of polymorphic changes was considerably different between genes, BRCA1 (55%) and BRCA2 (19.4%). By looking at the protein level, the changes observed within the BRCA1 and BRCA2 genes could affect not only the nucleic location of the protein but also disrupt the folding and, therefore, the tumor suppressor function.

Evidence that heparin but not hirudin reduces PAI-1 expression in cultured human endothelial cells.

Heparin and other antithrombotic drugs besides their anticoagulant action could have a profibrinolytic effect. We have analyzed the effect of unfractionated heparin (UFH) and hirudin on PAI-1 gene expression in human umbilical vein endothelial cells (HUVEC). Cells were stimulated with UFH (1 and 10 IU/ml) and hirudin (20 and 100 TIU/ml). Samples were obtained before and 2, 6, and 24 hours after stimulation. mRNA analysis was conducted by reverse transcription followed by polymerase chain reaction, and PAI-1 antigen was determined by ELISA. Addition of UFH (10 IU/ml) to HUVEC resulted in a decrease of PAI-1 mRNA at 6 hours (40% reduction) and 24 hours (60% reduction) and PAI-1 antigen. Hirudin, however, did not modify significantly the PAI-1 mRNA nor the inhibitor secretion. The addition of UFH (10 or 100 IU/ml) to endotoxin-stimulated HUVEC also reduced the increased PAI-1 mRNA and antigen secretion (45%), whereas no effect could be observed with hirudin. Our results suggest that UFH, but not hirudin, by reducing the endothelial expression of PAI-1 might have a profibrinolytic effect.

[Active immunotherapy in the treatment of haematological neoplasias]. / Inmunoterapia activa en el tratamiento de neoplasias hematológicas.

The continuous search for therapeutic approaches that improve the conventional treatments of neoplasms, together with an improved understanding of the immune system, has led in recent years to the development of Immunotherapy. Basically, a distinction can be made between two forms of immunotherapy: passive immunotherapy, which consists in the transfer of antibodies or cells previously generated in vitro that are directed against the tumour, and active immunotherapy, which attempts to activate in vivo the immune system and induce it to elaborate a specific response against the tumor antibodies. Hematological neoplasms, specifically some B lymphomas, express in their membrane an immunoglobulin that is considered a specific antigen of the tumour, which is why these diseases have become the ideal target for immunotherapy treatments. There are many alternatives, ranging from protein vaccines, which have already shown clinical benefits, to those of the second generation, which make use of the new techniques of molecular biology to increase the efficacy of the vaccines and obtain their production in a quicker and less costly way, but with which there are not yet definitive clinical results.

[Past, present and future of anti-idiotype vaccination]. / Pasado, presente y futuro de la vacunación anti-idiotipo.

Cancer vaccines are conceived as therapeutic tools, in contrast to the prophylactic vaccines used to fight against infectious diseases. Among the most potent therapeutic vaccines, anti-idiotype vaccination is directed against the tumor idiotype, the only well-characterized tumor antigen displayed in neoplastic B-cells. Anti-idiotype vaccines have demonstrated clinical benefit against follicular lymphoma and are currently being evaluated in two different phase III clinical trials. Additional emerging strategies, which include the use of dendritic cells and the production of vaccines via molecular means will surely allow us to draw important conclusions concerning the treatment of cancer patients.

Weight loss in tumour-bearing mice is not associated with changes in resistin gene expression in white adipose tissue.

Resistin, a product of white adipose tissue, is postulated to induce insulin resistance in obesity and regulate adipocyte differentiation. The aim of this study was to examine resistin gene expression in adipose tissue from mice bearing the MAC16 adenocarcinoma, which induces cancer cachexia with marked wasting of adipose tissue and skeletal muscle mass. MAC16-bearing mice lost weight progressively over the period following tumour transplantation, while the weight of control mice remained stable. Leptin mRNA in gonadal fat was 50 % lower in MAC16 mice than in controls (p < 0.05). Plasma insulin concentrations were also significantly lower in the MAC16 group (p < 0.05). However, resistin mRNA level in gonadal fat in MAC16 mice was similar to controls (94 % of controls). Thus, despite severe weight loss and significant falls in leptin expression and insulin concentration, resistin gene expression appears unchanged in white adipose tissue of mice with MAC16 tumour. Maintenance of resistin production may help inhibit the formation of new adipocytes in cancer cachexia.

Vacuna idiotípica en el tratamiento del linfoma folicular: situación actual y perspectivas futuras / Idiotype vaccines in the treatment of follicular lymphoma: current status and future perspectives

El linfoma folicular (LF) está considerado como elsegundo tipo de linfoma no-Hodgkin más común, representandomás del 20% del total de los linfomas. Es unaenfermedad de progresión lenta y curso indolente enla que, a pesar de la buena respuesta al tratamiento,las recaídas son muy frecuentes y cada vez es más difícilconseguir respuestas completas. Por ello, se puedeconsiderar que hasta el momento, el LF es incurable.La búsqueda continua de nuevas estrategias terapéuticasen enfermedades neoplásicas, junto con un mejorconocimiento del sistema inmunitario, ha llevado ala aparición de una nueva disciplina, conocida con elnombre de inmunoterapia, que aprovecha la capacidaddel sistema inmunitario de atacar lo extraño sin dañarlo propio. El LF es un tumor muy apropiado para estetipo de tratamiento por presentar un antígeno específicode tumor: el idiotipo de la inmunoglobulina monoclonalexpresada en la membrana de todas las célulastumorales. Se han realizado diversos estudios en losque se ha probado la inmunoterapia como tratamientocomplementario al tratamiento convencional. Recientemente,nuestro grupo ha publicado un estudio en el quese observa claramente que los resultados que se obtienentras la vacunación idiotípica, cuando se consigue lainmunización adecuada del paciente, son mejores quelos obtenidos con quimioterapia sola. En este sentido,es necesario seguir investigando para aclarar si la vacunaciónidiotípica pudiera no sólo mantener remisionescompletas duraderas en los pacientes vacunados, sinoincluso conseguir la curación de los mismos. Por ello,resulta interesante abordar un mejor planteamiento delos ensayos clínicos, la mejora de la producción de lavacuna y el estudio de mecanismos de la célula tumoralcapaces de modificar la inmunoglobulina específica del tumor(AU)

Follicular lymphoma is the second most prevalentnon-Hodgkin lymphoma, representing 20% of all lymphomas.Follicular lymphoma is an indolent diseasewith a slow progression in which, although exhibitinga good response to treatment, relapse is very frequentand complete remission is not easy to maintain. Therefore,the disease is regarded as incurable. The searchfor new therapeutic strategies, together with a betterunderstanding of the immune system, has led to theemergence of a new treatment named immunotherapy.Follicular lymphoma is a malignancy suitable for thiskind of treatment given the fact that it is characterizedby presenting a unique tumour-specific antigen: theidiotype of the monoclonal immunoglobulin displayedon the membrane of tumour cells. Several studies havebeen conducted to test immunotherapy as complementaryto conventional treatment. In a previous study byour group, a clear benefit was evident is obtained afteridiotypic vaccination, when an adequate immunizationof the patient is obtained, in comparison to chemotherapyalone. In this sense, analysis is needed of whetheridiotypic vaccination can produce not only long-lastingand complete remission, but even cure. It would be ofgreat interest to consider an optimisation of the experimentaldesign of clinical trials, an improvementof vaccine production, and the study of the molecularmechanisms of the tumour cell which modify the targetimmunoglobulin(AU)

Inmunoterapia activa en el tratamiento de neoplasias hematológicas / Active immunotherapy in the treatment of haematological neoplasias

La continua búsqueda de abordajes terapéuticos que mejoren los tratamientos convencionales de las enfermedades neoplásicas junto con el mejor conocimiento del sistema inmunitario ha llevado en los últimos años al desarrollo de la inmunoterapia. Básicamente se pueden distinguir dos formas de inmunoterapia: la inmunoterapia pasiva, que consiste en la transferencia de anticuerpos o células previamente generados in vitro que se dirigen contra el tumor, y la inmunoterapia activa, que pretende activar in vivo el sistema inmunitario e inducirlo a elaborar una respuesta específica contra los antígenos tumorales. Las neoplasias hematológicas, concretamente algunos linfomas B, expresan en su membrana una inmunoglobulina que se considera un verdadero antígeno específico de tumor; por eso estas enfermedades se han convertido en la diana ideal de los tratamientos de inmunoterapia. Las alternativas son muchas, desde las vacunas proteicas que ya han demostrado beneficios clínicos, hasta las de segunda generación, que aprovechan las nuevas técnicas de biología molecular para aumentar la eficacia de las vacunas y conseguir su producción de forma más rápida y menos costosa, pero con las que todavía no hay resultados clínicos definitivos (AU)

Conceptos básicos en biología molecular del cáncer. Susceptibilidad genética / Basic concepts in the molecular biology of cancer. Genetic susceptibility

En los últimos años se han producido cambios en la biología molecular que nos permiten optimizar el tratamiento de cáncer, minimizando los efectos secundarios, y actuar a nivel de la prevención a partir del estudio de los procesos biológicos que subyacen en la enfermedad. Uno de los aspectos más destacados se dirige a la capacidad con la que contamos actualmente de poder analizar el ADN y/o ARN fruto de los descubrimientos y progresos en la segunda mitad del siglo XX. Todas estas innovaciones tecnológicas y en el campo de la genética molecular preparan el camino para la comprensión y el análisis funcional que se deriva de la información contenida en el genoma humano. Asimismo el estudio de algunos de los múltiples eventos moleculares que acontecen en el proceso multifactorial del cáncer, permiten ofrecer una nueva visión de los factores pronósticos al tiempo que identifican individuos con una gran susceptibilidad de desarrollar determinados tipos de cáncer. Algunos de estos genes asociados a cáncer pueden alterarse como consecuencia de mutágenos endógenos, mutaciones a nivel de línea germinal, que ocurren durante la replicación celular y que pueden incrementar la inestabilidad genómica en células precancerosas. En la misma línea, los avances de la biotecnología ofrecen la posibilidad de contar con una visión amplia de un amplio espectro de eventos moleculares involucrados en el proceso neoplásico. (AU)