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

Variations in “rescuability” of immunoglobulin molecules from different forms of human lymphoma: implications for anti-idiotype vaccine development

Idiotypic (Id) vaccination has shown promising results in patients with follicular lymphoma (FL). However, it still remains unclear whether the same approach might be suitable for the treatment of other B-cell malignancies. For this reason, we recently performed an interim analysis of patients proposed to receive this treatment at our center. The feasibility of employing idiotype vaccines was evaluated for five different B-cell malignancies in their first relapse, both in terms of induction and fusion, as well as overall treatment. Our data suggest that, unlike follicular lymphoma (87%), this approach is not feasible to treat other B-cell malignancies (0–20%) such as mantle cell, small lymphocytic, diffuse large cell and Burkitt’s lymphoma (P < 0.01). The main difficulties encountered were technical problems related to the survival of idiotype-producing hybridomas (83%) and the early loss of idiotype production by growing hybridomas (17%). However, it remains possible that an idiotype vaccine might still be produced through molecular means for most, if not all cases of relapsing B-cell malignancies

Altered patterns of expression of members of the heterogeneous nuclear ribonucleoprotein (hnRNP) family in lung cancer

hnRNP A2/B1 has been suggested as a useful early detection marker for lung carcinoma. hnRNP A2/B1 is a member of a large family of heterogeneous nuclear ribonucleoproteins (hnRNP proteins) involved in a variety of functions, including regulation of transcription, mRNA metabolism, and translation. In lung cancer, we have evaluated the expression and cellular localization of several members of the hnRNP family, hnRNP A1, A2, B1, C1, C2 and K. 16 cell lines (SCLC and NSCLC) and biopsies from 32 lung cancer patients were analyzed. Our results suggest that, besides hnRNP A2/B1, the expression of other members of the hnRNP family is altered both in SCLC and NSCLC. In the biopsies, negative or low expression of the hnRNP proteins analyzed was observed in normal epithelial cells whereas lung cancer cells showed highly intense nuclear or cytoplasmic immunolocalization. In all the lung cancer cell lines, the mRNA for all the hnRNP proteins was detected. In general, higher levels of hnRNP mRNAs were found in SCLC as compared with NSCLC. Our results also suggest that the expression and processing of each hnRNP protein in lung cancer is independently regulated and is not exclusively related to proliferation status. In SCLC cell lines, hnRNP A1 protein expression correlated with that of Bcl-x(L). In the lung cancer cell lines, hnRNP K protein localization varied with the cellular confluence

Active immunotherapy in the treatment of haematological neoplasias

Abstract 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

Acquired potential N-glycosylation sites within the tumor-specific immunoglobulin heavy chains of B-cell malignancies

Background and Objectives. Among B-cell malignancies, follicular lymphomas (FL) more frequently show acquired, potential N-glycosylation sites (AGS) within tumor-specific immunoglobulin. The aim of this study was to extend this observation and to evaluate the pattern of presentation of AGS within five different forms of B-cell lymphoma. Design and Methods. We sequenced the tumor-specific immunoglobulin heavy chain variable region fragment, including complementarity-determining regions 2 and 3, of forty-seven consecutive patients with a B-cell malignancy enrolled in idiotype vaccine clinical trials. This sequencing approach is known to allow the identification of most AGS. We then statistically analyzed differences in presentation pattern, in terms of tumor histology, immunoglobulin isotype, AGS location and amino acid composition. Results. All twenty-four FL cases presented with at least one AGS, whereas the vast majority of four B-cell lymphoma types other than FL did not. The non- FL group of tumors included four cases of Burkitt’s lymphoma, six of diffuse large cell lymphoma, seven mantle cell lymphomas and six small lymphocytic lymphomas. Most IgM-bearing follicular lymphoma cases featured their AGS within complementarity-determining region 2, as opposed to those bearing an IgG, which mostly displayed the AGS within complementarity- determining region 3. The vast majority of AGS located within either complementarity- determining region ended with a serine residue, whereas those located within framework regions mostly featured threonine as the last amino acid residue. Interpretation and Conclusions. In our series, all cases of FL had AGS within their tumor-specific immunoglobulin heavy chain variable regions. In contrast, most B-cell malignancies other than FL did not. Further studies are warranted in order to establish the possible meaning of these findings in terms of disease pathogenesis, their diagnostic value in doubtful cases and their potential implications for immunotherapy

El receptor del factor de crecimiento epitelial EGFR como diana terapéutica en cáncer colorrectal

La terapia dirigida al receptor del factor de crecimiento epitelial o EGFR (Epidermal Growth Factor Receptor) es una novedosa área de investigación clínica que actualmente cuenta con varias moléculas que han demostrado actividad en pacientes con cáncer. Diversos estudios experimentales han relacionado el factor de creci- miento epidérmico (EGF) con el desarrollo y progresión de enfermedad en modelos experimentales de cáncer colorrectal (CCR). Estos hallazgos son sugestivos que CCR puede responder a la terapia dirigida frente a EGFR. La experiencia actual con inhibidores de la tirosina quinasa de EGFR, anticuerpos monoclonales anti EGFR y oligonucleótidos antisentido han demostrado efecto antitumoral y proporciona un fundamento para su evaluación clínica, solos o combinados con drogas citotóxicas. No obstante, son necesarios nuevos estudios y un mayor seguimiento, para confirmar si el actual nivel de entusiasmo se ajustará al impacto terapéutico.Novel targeted therapies which can block the epidermal growth factor receptor (EGFR) have demonstrated activity in the laboratory and in clinical settings. Different agents have been developed and are being tested in cancer patients Studies have shown active single-agent efficacy and efficacy in combination with chemotherapy and/or radiation therapy Some published data have shown that Epidermal Growth Factor (EGF) mediates colorectal cancer growth. These observations suggest anti- EGFR-targeted therapies including anti-EGFR monoclonal antibodies, immunotoxin conjugates, and EGFR tyrosine-kinase inhibitors can play a role in the treatment of colorectal cancer. New studies aimed at blocking this signaling pathway are needed to elucidate the role of these promising new targeted therapies in the treatment of colorectal cancer

Susceptibilidad genética en cáncer de colon

Algunos casos de cáncer presentan una clara causa genética bien definida. Para demostrar la existencia, de forma objetiva, de un cáncer hereditario es necesario identificar la mutación causante en un gen concreto de la línea germinal. La mayoría de los síndromes familiares se transmiten como enfermedades autosómicas dominantes y gran parte de los genes asociados a estos síndromes son genes supresores (APC en el caso de la FAP y MLH1 y MSH2 en el HNPCC). En estos casos hereditarios está recomendado el estudio genético de la familia. Las mutaciones familiares encontradas podrían ayudar a comprender el comportamiento del cáncer.The occurrence of cancer is occasionally explained by genetic alterations. In order to distinguish between a sporadic or hereditary cancer, it becomes necessary to identify a defined mutation on a single gene within the germinal line. Most of the known familial syndromes are autosomic dominant inherited. Frequently, the genes implicated in these disorders are tumor suppressor genes (APC associated with FAP and, MLH1 and MSH2 associated with HNPCC). In the hereditary cases, genetic study of the family is strongly recommended. Moreover, detection of the family mutations could help us understand better the behavior of the cancer

Farmacogenómica en el cáncer colorrectal

La investigación en el proyecto genoma humano va a favorecer en los próximos años el desarrollo farmacoterapias más personalizadas. La Farmacogenómica es una nueva disciplina que se ha desarrollado en los últimos años y cuyos objetivos se dirigen a conocer aquellos mecanismos que permitan explicar cómo la base genética de cada individuo afecta a la respuesta obtenida a las drogas. La posibilidad de predecir qué terapias son más efectivas para un determinado paciente va a constituir una poderosa herramienta médica, particularmente en el ámbito de la oncología. Es probable que estas predic- ciones deriven de una mejor comprensión de la enfermedad tanto a nivel celular como molecular. Por lo que respecta al cáncer colorrectal, los avances en el conocimiento de la etiología de la enfermedad a nivel molecular no se han asociado con una mejora en el tratamiento del paciente. La eficacia clínica y la toxicidad de las drogas más utilizadas en el tratamiento del cáncer colorrectal de cada paciente son por el momento impredecibles. Entre otras muchas variables, se han descrito determinados polimorfismos en genes implicados en el metabolismo de estas drogas que determinan la variabilidad interindividual tanto en la eficacia terapeútica como en la toxicidad. La investigación de las características moleculares del cáncer colorrectal y el desarrollo de nuevas terapias dirigidas a dianas específicas van a permitir en el futuro predecir la respuesta de la neoplasia y, por tanto, modificar la opción terapeútica buscando aquella que mejor se ajuste al perfil biológico.Advances in human genome research will make it possible to personalize pharmacotherapy. Pharmacogenomics has been defined as the study of mechanisms that explain how an individual's genetic inheritance affects the response to drugs. The ability to predict which therapies are most likely to be effective for certain patients would constitute a powerful medical tool, particularly in oncology. Such predictions would be likely to arise from an understanding of the disease on the cellular and molecular level. For colorectal cancer, our increased knowledge of the molecular etiology of the disease has not yet been paralleled by an improvement in patient care. Clinical efficacy and also toxicity of a given chemotherapy are still largely unpredictable for the individual patient. Amongst other variables, genetic polymorphisms determine the interindividual heterogeneity in both toxicity and therapeutic efficacy. Due to the better molecular characterization of colorectal cancer and the development of new target-directed therapies, it should be possible to predict which therapeutic interventions will have a high likelihood of success for an individual patient

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