RESUMEN
Treatment for renal cell carcinoma (RCC) has improved dramatically over the last decade, shifting from high-dose cytokine therapy in combination with surgical resection of tumors to targeted therapy, immunotherapy, and combination therapies. However, curative treatment, particularly for advanced-stage disease, remains rare. Cell therapy as a "living drug" has achieved hematological malignancy cures with a high response rate, and significant research efforts have been made to facilitate its translation to solid tumors. Herein, we overview the cellular therapies for RCC focusing on allogeneic hematopoietic stem cell transplantation, T cell receptor gene-modified T cells, chimeric antigen receptor (CAR) T cells, CAR natural killer (NK) cells, lymphokine-activated killer (LAK) cells, γδ T cells, and dendritic cell vaccination. We have also included perspectives for using other recent approaches, such as CAR macrophages, dendritic cell-cytokine induced killer cells and regulatory CAR-T cells to shed light on preclinical development of cell therapy and advancing cell therapy into clinic to achieve cures for RCC.
Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/terapia , Inmunoterapia , Tratamiento Basado en Trasplante de Células y Tejidos , Terapia Combinada , Neoplasias Renales/terapiaRESUMEN
CD19-targeted chimeric antigen receptors (CAR) T cells are one of the most remarkable cellular therapies for managing B cell malignancies. However, long-term disease-free survival is still a challenge to overcome. Here, we evaluated the influence of different hinge, transmembrane (TM), and costimulatory CAR domains, as well as manufacturing conditions, cellular product type, doses, patient's age, and tumor types on the clinical outcomes of patients with B cell cancers treated with CD19 CAR T cells. The primary outcome was defined as the best complete response (BCR), and the secondary outcomes were the best objective response (BOR) and 12-month overall survival (OS). The covariates considered were the type of hinge, TM, and costimulatory domains in the CAR, CAR T cell manufacturing conditions, cell population transduced with the CAR, the number of CAR T cell infusions, amount of CAR T cells injected/Kg, CD19 CAR type (name), tumor type, and age. Fifty-six studies (3493 patients) were included in the systematic review and 46 (3421 patients) in the meta-analysis. The overall BCR rate was 56%, with 60% OS and 75% BOR. Younger patients displayed remarkably higher BCR prevalence without differences in OS. The presence of CD28 in the CAR's hinge, TM, and costimulatory domains improved all outcomes evaluated. Doses from one to 4.9 million cells/kg resulted in better clinical outcomes. Our data also suggest that regardless of whether patients have had high objective responses, they might have survival benefits from CD19 CAR T therapy. This meta-analysis is a critical hypothesis-generating instrument, capturing effects in the CD19 CAR T cells literature lacking randomized clinical trials and large observational studies.
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Antígenos CD19 , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Humanos , Factores de Edad , Antígenos CD19/inmunología , Inmunoterapia Adoptiva/métodos , Leucemia de Células B/terapia , Leucemia de Células B/inmunología , Leucemia de Células B/mortalidad , Linfoma de Células B/inmunología , Linfoma de Células B/terapia , Linfoma de Células B/mortalidad , Receptores de Antígenos de Linfocitos T/inmunología , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Resultado del TratamientoRESUMEN
The complete regression of clear cell renal cell carcinoma (ccRCC) obtained pre-clinically with anti-carbonic anhydrase IX (CAIX) G36 chimeric antigen receptor (CAR) T cells in doses equivalent to â 108 CAR T cells/kg renewed the potential of this target to treat ccRCC and other tumors in hypoxia. The immune checkpoint blockade (ICB) brought durable clinical responses in advanced ccRCC and other tumors. Here, we tested CD8α/4-1BB compared to CD28-based anti-CAIX CAR peripheral blood mononuclear cells (PBMCs) releasing anti-programmed cell death ligand-1 (PD-L1) IgG4 for human ccRCC treatment in vitro and in an orthotopic NSG mice model in vivo. Using a â 107 CAR PBMCs cells/kg dose, anti-CAIX CD28 CAR T cells releasing anti-PD-L1 IgG highly decrease both tumor volume and weight in vivo, avoiding the occurrence of metastasis. This antitumoral superiority of CD28-based CAR PBMCs cells compared to 4-1BB occurred under ICB via PD-L1. Furthermore, the T cell exhaustion status in peripheral CD4 T cells, additionally to CD8, was critical for CAR T cells efficiency. The lack of hepatotoxicity and nephrotoxicity upon the administration of a 107 CAR PMBCs cells/kg dose is the basis for carrying out clinical trials using anti-CAIX CD28 CAR PBMCs cells releasing anti-PD-L1 antibodies or anti-CAIX 4-1BB CAR T cells, offering exciting new prospects for the treatment of refractory ccRCC and hypoxic tumors.
Asunto(s)
Antígeno B7-H1 , Anhidrasa Carbónica IX , Carcinoma de Células Renales , Neoplasias Renales , Receptores Quiméricos de Antígenos , Animales , Anticuerpos/inmunología , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/inmunología , Antígenos CD28 , Anhidrasa Carbónica IX/inmunología , Carcinoma de Células Renales/inmunología , Carcinoma de Células Renales/patología , Carcinoma de Células Renales/terapia , Inhibidores de Puntos de Control Inmunológico , Neoplasias Renales/inmunología , Neoplasias Renales/patología , Neoplasias Renales/terapia , Leucocitos Mononucleares/patología , Ratones , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: Trastuzumab is an antibody widely used in the treatment of breast cancer cases that test positive for the human epidermal growth factor receptor 2 (HER2). Many patients, however, become resistant to this antibody, whose resistance has become a major focus in breast cancer research. But despite this interest, there are still no reliable markers that can be used to identify resistant patients. A possible role of several extracellular matrix (ECM) components--heparan sulfate (HS), Syn-1(Syndecan-1) and heparanase (HPSE1)--in light of the influence of ECM alterations on the action of several compounds on the cells and cancer development, was therefore investigated in breast cancer cell resistance to trastuzumab. METHODS: The cDNA of the enzyme responsible for cleaving HS chains from proteoglycans, HPSE1, was cloned in the pEGFP-N1 plasmid and transfected into a breast cancer cell lineage. We evaluated cell viability after trastuzumab treatment using different breast cancer cell lines. Trastuzumab and HS interaction was investigated by confocal microscopy and Fluorescence Resonance Energy Transfer (FRET). The profile of sulfated glycosaminoglycans was also investigated by [35S]-sulfate incorporation. Quantitative RT-PCR and immunofluorescence were used to evaluate HPSE1, HER2 and Syn-1 mRNA expression. HPSE1 enzymatic activity was performed using biotinylated heparan sulfate. RESULTS: Breast cancer cell lines responsive to trastuzumab present higher amounts of HER2, Syn-1 and HS on the cell surface, but lower levels of secreted HS. Trastuzumab and HS interaction was proven by FRET analysis. The addition of anti-HS to the cells or heparin to the culture medium induced resistance to trastuzumab in breast cancer cells previously sensitive to this monoclonal antibody. Breast cancer cells transfected with HPSE1 became resistant to trastuzumab, showing lower levels of HER2, Syn-1 and HS on the cell surface. In addition, HS shedding was increased significantly in these resistant cells. CONCLUSION: Trastuzumab action is dependent on the availability of heparan sulfate on the surface of breast cancer cells. Furthermore, our data suggest that high levels of heparan sulfate shed to the medium are able to capture trastuzumab, blocking the antibody action mediated by HER2. In addition to HER2 levels, heparan sulfate synthesis and shedding determine breast cancer cell susceptibility to trastuzumab.
Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Antineoplásicos/farmacología , Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos , Heparitina Sulfato/metabolismo , Anticuerpos Monoclonales Humanizados/metabolismo , Antineoplásicos/metabolismo , Neoplasias de la Mama/genética , Línea Celular Tumoral , Membrana Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica , Glucuronidasa/genética , Glucuronidasa/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Células MCF-7 , Unión Proteica , Transporte de Proteínas , Receptor ErbB-2/antagonistas & inhibidores , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Sindecano-1/genética , Sindecano-1/metabolismo , TrastuzumabRESUMEN
CAR-T cell therapy, in which T cells are transfected or transduced with a chimeric antigen receptor (CAR), is a transformative type of cancer immunotherapy. Despite outstanding success in hematological malignancies, their efficacy against solid tumors has been limited. Here, we aimed to explore whether T cells modified by a CAR targeting the vascular endothelial growth factor 2 receptor/ kinase insert domain receptor (KDR) could destroy tumors and their vasculature. A second-generation KDR-CAR was constructed and transfected into T cells using lentivirus. The 3D structure of the CAR construct and target antigen was predicted. Moreover, in silico analysis, including molecular docking and molecular dynamics (MD) simulation, were used to evaluate the minimum energy of interaction and stability of the complex. The anti-cancer effect of KDR-specific CAR-T cells was tested with KDR-expressing and KDR overexpressing A549 cell line. The in-silico study suggested that this CAR construct could be effective for lung cancer therapy. We evaluated this using both in vitro and in vivo experiments. The KDR-CAR-T cells targeted and killed KDR-A549 with high efficiency by expressing IFN-γ and releasing granzyme B. The in vivo study showed that KDR-CAR-T cells dramatically inhibited the growth of lung cancer KDR-A549 xenografts in BALB/c-nu mice at day 10. The characterization of T cells modified by KDR-CAR by computational biology and wet-lab experiments suggested its applicability as a new treatment strategy for lung cancer and, potentially, for other vascularized solid tumors.
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Carcinoma de Pulmón de Células no Pequeñas , Inmunoterapia Adoptiva , Neoplasias Pulmonares , Receptores Quiméricos de Antígenos , Animales , Humanos , Ratones , Carcinoma de Pulmón de Células no Pequeñas/terapia , Línea Celular Tumoral , Neoplasias Pulmonares/terapia , Simulación del Acoplamiento Molecular , Receptores Quiméricos de Antígenos/genética , Linfocitos T , Factor A de Crecimiento Endotelial Vascular , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Inmunoterapia Adoptiva/métodosRESUMEN
A better understanding of the molecular mechanisms of renal cell carcinogenesis could contribute to a decrease in the mortality rate of this disease. The aim of this study was to evaluate the glycosaminoglycans profile and heparanase expression in renal cell carcinoma. The study included 24 patients submitted to nephrectomy with confirmed pathological diagnosis of renal cell carcinoma. The majority of the samples (87.5%) were classified in the initial stage of renal cell carcinoma (clinical stages I and II). Heparanase messenger ribonucleic acid expression was evaluated by quantitative real-time reverse transcription polymerase chain reaction, and sulfated glycosaminoglycans were identified and quantified by agarose gel electrophoresis of renal cell carcinoma samples or non-neoplastic tissues obtained from the same patients (control group). The sulfated glycosaminoglycans and hyaluronic acid were analyzed in urine samples of the patients before and after surgery. The data showed a significant statistical increase in chondroitin sulfate, and a decrease in heparan sulfate and dermatan sulfate present in neoplastic tissues compared with non-neoplastic tissues. Higher heparanase messenger ribonucleic acid expression in the neoplastic tissues was also shown, compared with the non-neoplastic tissues. The urine glycosaminoglycans profile showed no significant difference between renal cell carcinoma and control samples. Extracellular matrix changes observed in the present study clarify that heparanase is possibly involved with heparan sulfate turnover, and that heparanase and the glycosaminoglycans can modulate initial events of renal cell carcinoma development.
Asunto(s)
Carcinoma de Células Renales/metabolismo , Glucuronidasa/biosíntesis , Glicosaminoglicanos/metabolismo , Neoplasias Renales/metabolismo , Carcinoma de Células Renales/cirugía , Sulfatos de Condroitina/metabolismo , Electroforesis en Gel de Agar , Glicosaminoglicanos/orina , Humanos , Ácido Hialurónico/metabolismo , Neoplasias Renales/cirugía , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
The carbonic anhydrase isoform IX (CAIX) enzyme is constitutively overexpressed in the vast majority of clear cell renal cell carcinoma (ccRCC) and can also be induced in hypoxic microenvironments, a major hallmark of most solid tumors. CAIX expression is restricted to a few sites in healthy tissues, positioning this molecule as a strategic target for cancer immunotherapy. In this review, we summarized preclinical and clinical data of immunotherapeutic strategies based on monoclonal antibodies (mAbs), fusion proteins, chimeric antigen receptor (CAR) T, and NK cells targeting CAIX against different types of solid malignant tumors, alone or in combination with radionuclides, cytokines, cytotoxic agents, tyrosine kinase inhibitors, or immune checkpoint blockade. Most clinical studies targeting CAIX for immunotherapy were performed using G250 mAb-based antibodies or CAR T cells, developed primarily for bioimaging purposes, with a limited clinical response for ccRCC. Other anti-CAIX mAbs, CAR T, and NK cells developed with therapeutic intent presented herein offered outstanding preclinical results, justifying further exploration in the clinical setting.
RESUMEN
New approaches to cancer immunotherapy have been developed, showing the ability to harness the immune system to treat and eliminate cancer. For many solid tumors, therapy with checkpoint inhibitors has shown promise. For hematologic malignancies, adoptive and engineered cell therapies are being widely developed, using cells such as T lymphocytes, as well as natural killer (NK) cells, dendritic cells, and potentially others. Among these adoptive cell therapies, the most active and advanced therapy involves chimeric antigen receptor (CAR)-T cells, which are T cells in which a chimeric antigen receptor is used to redirect specificity and allow T cell recognition, activation and killing of cancers, such as leukemia and lymphoma. Two autologous CAR-T products have been approved by several health authorities, starting with the U.S. Food and Drug Administration (FDA) in 2017. These products have shown powerful, inducing, long-lasting effects against B cell cancers in many cases. In distinction to the results seen in hematologic malignancies, the field of using CAR-T products against solid tumors is in its infancy. Targeting solid tumors and trafficking CAR-T cells into an immunosuppressive microenvironment are both significant challenges. The goal of this review is to summarize some of the most recent aspects of CAR-T cell design and manufacturing that have led to successes in hematological malignancies, allowing the reader to appreciate the barriers that must be overcome to extend CAR-T therapies to solid tumors successfully.
RESUMEN
Advances in the treatment of metastatic clear cell renal cell carcinoma (ccRCC) have led to improved progression-free survival of many patients; however the therapies are toxic, rarely achieve durable long-term complete responses and are not curative. Herein we used a single bicistronic lentiviral vector to develop a new combination immunotherapy that consists of human anti-carbonic anhydrase IX (CAIX)-targeted chimeric antigen receptor (CAR) T cells engineered to secrete human anti-programmed death ligand 1 (PD-L1) antibodies at the tumor site. The local antibody delivery led to marked immune checkpoint blockade. Tumor growth diminished 5 times and tumor weight reduced 50-80% when compared with the anti-CAIX CAR T cells alone in a humanized mice model of ccRCC. The expression of PD-L1 and Ki67 in the tumors decreased and an increase in granzyme B levels was found in CAR T cells. The anti-PD-L1 IgG1 isotype, which is capable of mediating ADCC, was also able to recruit human NK cells to the tumor site in vivo. These armed second-generation CAR T cells empowered to secrete human anti-PD-L1 antibodies in the ccRCC milieu to combat T cell exhaustion is an innovation in this field that should provide renewed potential for CAR T cell immunotherapy of solid tumors where limited efficacy is currently seen.
Asunto(s)
Antígeno B7-H1/inmunología , Linfocitos T CD8-positivos/inmunología , Carcinoma de Células Renales/terapia , Inmunoterapia/métodos , Neoplasias Renales/terapia , Subgrupos Linfocitarios/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Animales , Anticuerpos/inmunología , Antígenos de Neoplasias/inmunología , Antígeno B7-H1/biosíntesis , Anhidrasas Carbónicas/inmunología , Carcinoma de Células Renales/inmunología , Línea Celular Tumoral , Quimera/inmunología , Modelos Animales de Enfermedad , Granzimas/metabolismo , Células HEK293 , Humanos , Antígeno Ki-67/biosíntesis , Neoplasias Renales/inmunología , Células Asesinas Naturales/inmunología , RatonesRESUMEN
CONTEXT AND OBJECTIVE: Heparanase-1 degrades heparan sulfate and has been correlated with tumor progression. Although the isoform heparanase-2 has no catalytic activity, it seems to be important for modulating heparanase-1 activity. Cathepsin B is a proteinase involved in tumor metastasis. The aim of this study was to analyze heparanase isoform expression and cathepsin B activity in plasma samples from patients with gastrointestinal carcinomas, compared with healthy individuals (control group). DESIGN AND SETTING: This was an analytical cross-sectional study. Peripheral blood samples were collected at a Brazilian public hospital, from 21 patients with histopathological diagnoses of gastrointestinal carcinomas and from 43 healthy individuals. The analyses were performed in two Brazilian medical schools. METHODS: Heparanase isoforms were identified and quantified in plasma samples by means of Western blot. The enzymatic activities of heparanase-1 and cathepsin B were also measured. RESULTS: The results demonstrated that the expression of both heparanase isoforms was significantly greater in plasma samples from gastrointestinal carcinoma patients, compared with the control group. Logistic regression analysis showed that increased heparanase-1 and heparanase-2 expression was exclusively dependent on the tumor. There was a significant increase in heparanase-1 and cathepsin B activity in the patients' plasma. CONCLUSION: Overexpression of heparanase-1 and heparanase-2, along with increased heparanase-1 and cathepsin B activity in plasma, is associated with the diagnosis of gastrointestinal carcinoma. These findings provide support for using non-invasive assays (plasma samples) as an auxiliary method for diagnosing gastrointestinal tumors.
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Biomarcadores de Tumor/sangre , Carcinoma/enzimología , Catepsina B/sangre , Neoplasias Gastrointestinales/enzimología , Glucuronidasa/sangre , Anciano , Anciano de 80 o más Años , Western Blotting/métodos , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Técnicas para Inmunoenzimas , Isoenzimas/sangre , Masculino , Persona de Mediana EdadRESUMEN
INTRODUCTION: The search for a specific marker that could help to distinguish between differentiated thyroid carcinoma and benign lesions remains elusive in clinical practice. Heparanase (HPSE) is an endo-beta-glucoronidase implicated in the process of tumor invasion, and the heparanase-2 (HPSE2) modulates HPSE activity. The aim of this study was to evaluate the role of heparanases in the development and differential diagnosis of follicular pattern thyroid lesions. METHODS: HPSE and HPSE2 expression by qRT-PCR, immunohistochemistry evaluation, western blot analysis and HPSE enzymatic activity were evaluated. RESULTS: The expression of heparanases by qRT-PCR showed an increase of HPSE2 in thyroid carcinoma (P = 0.001). HPSE activity was found to be higher in the malignant neoplasms than in the benign tumors (P<0.0001). On Western blot analysis, HPSE2 isoforms were detected only in malignant tumors. The immunohistochemical assay allowed us to establish a distinct pattern for malignant and benign tumors. Carcinomas showed a typical combination of positive labeling for neoplastic cells and negative immunostaining in colloid, when compared to benign tumors (P<0.0001). The proposed diagnostic test presents sensitivity and negative predictive value of around 100%, showing itself to be an accurate test for distinguishing between malignant and benign lesions. CONCLUSIONS: This study shows, for the first time, a distinct profile of HPSE expression in thyroid carcinoma suggesting its role in carcinogenesis.
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Glucuronidasa/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias de la Tiroides/metabolismo , Neoplasias de la Tiroides/patología , Diagnóstico Diferencial , Femenino , Humanos , Inmunohistoquímica/métodos , Masculino , Persona de Mediana Edad , Glándula Tiroides/metabolismo , Glándula Tiroides/patologíaRESUMEN
AIMS AND BACKGROUND: Gemcitabine and vinblastine are chemotherapeutic drugs with a wide spectrum of antitumor activity. We conducted a phase I trial to define the maximal tolerated dose of this combination. METHODS: Twenty-nine patients with a variety of solid tumors with measurable disease were included. Twenty-seven of these patients had been previously treated with chemotherapy. The use of hematological growth factors was not allowed. The maximal tolerated dose was defined as the level in which WHO grades 3 or 4 non-hematological toxicity would occur in at least a third of the patients. RESULTS: The maximal tolerated dose was reached at level 5, which consisted of gemcitabine (1000 mg/m2) with vinblastine (3 mg/m2) given intravenously on days 1, 8 and 15 every 28 days. At this level, one patient had WHO grade 3 cerebellar toxicity and another WHO grade 4 anorexia. Furthermore, patients were able to receive all 3 weekly doses of chemotherapy in only 2 out of 10 cycles of treatment given at this level. We also observed 5 episodes of WHO grades 1 and 2 neuropathy, most of which (4/5) occurred in patients previously exposed to neurotoxic chemotherapy. We recorded 2 partial responses (one at level 3 and the other at level 4) and 8 instances of stable disease after 3 scheduled cycles of the combination. CONCLUSIONS: We therefore recommend gemcitabine (1100 mg/m2) plus vinblastine (5.5 mg/m2) given on days 1 and 8 every 21 days (level 4) for previously treated patients with solid tumors, with special caution in patients previously exposed to neurotoxic chemotherapy.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Desoxicitidina/análogos & derivados , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Antimetabolitos Antineoplásicos/administración & dosificación , Antineoplásicos Fitogénicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Desoxicitidina/administración & dosificación , Esquema de Medicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Vinblastina/administración & dosificación , GemcitabinaRESUMEN
CONTEXT AND OBJECTIVE: Heparanase-1 degrades heparan sulfate and has been correlated with tumor progression. Although the isoform heparanase-2 has no catalytic activity, it seems to be important for modulating heparanase-1 activity. Cathepsin B is a proteinase involved in tumor metastasis. The aim of this study was to analyze heparanase isoform expression and cathepsin B activity in plasma samples from patients with gastrointestinal carcinomas, compared with healthy individuals (control group). DESIGN AND SETTING: This was an analytical cross-sectional study. Peripheral blood samples were collected at a Brazilian public hospital, from 21 patients with histopathological diagnoses of gastrointestinal carcinomas and from 43 healthy individuals. The analyses were performed in two Brazilian medical schools. METHODS: Heparanase isoforms were identified and quantified in plasma samples by means of Western blot. The enzymatic activities of heparanase-1 and cathepsin B were also measured. RESULTS: The results demonstrated that the expression of both heparanase isoforms was significantly greater in plasma samples from gastrointestinal carcinoma patients, compared with the control group. Logistic regression analysis showed that increased heparanase-1 and heparanase-2 expression was exclusively dependent on the ...
CONTEXTO E OBJETIVO: A heparanase-1 degrada heparam sulfato e está relacionada à progressão de tumor. Apesar de a isoforma heparanase-2 não possuir atividade catalítica, parece ser importante para modular a atividade da heparanase-1. A catepsina B é uma proteinase envolvida na metástase de tumores. O objetivo deste estudo foi analisar a expressão das isoformas de heparanase e atividade da catepsina B em amostras de plasma de pacientes com carcinomas gastrointestinais, comparando-se com indivíduos saudáveis (grupo controle). TIPO DE ESTUDO E LOCAL: Este é um estudo transversal analítico. Foram coletadas amostras de sangue periférico, em hospital público brasileiro, de 21 pacientes com diagnóstico histopatológico de carcinoma gastrointestinal e 43 indivíduos saudáveis. As análises foram realizadas em duas faculdades de medicina brasileiras. MÉTODOS: As isoformas da heparanase foram identificadas e quantificadas em amostras de plasma por Western blot. As atividades enzimáticas de heparanase-1 e catepsina B foram também mensuradas. RESULTADOS: Os resultados demonstraram que as expressões das isoformas de heparanase foram significativamente maiores nas amostras de plasma de pacientes com carcinoma gastrointestinal em comparação com ...
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Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Biomarcadores de Tumor/sangre , Carcinoma/enzimología , Catepsina B/sangre , Neoplasias Gastrointestinales/enzimología , Glucuronidasa/sangre , Western Blotting/métodos , Estudios de Casos y Controles , Estudios Transversales , Técnicas para Inmunoenzimas , Isoenzimas/sangreRESUMEN
O dogma central da biologia molecular é formado por três processos, a síntese de DNA (replicação) síntese de RNA (transcrição) e síntese de proteínas (tradução). Tais processos podem ocorrer in vitro por mecanismos que ?mimetizam? os mecanismos de replicação e transcrição por reação de amplificação em cadeia da DNA polimerase (PCR) e por RT-PCR, que corresponde à reação de transcrição reversa, seguida da amplificação por PCR. Howard Temin, em 1961, foi pioneiro em juntar evidências que comprovaram certa inconsistência com o dogma central da biologia molecular para provar a existência da transcriptase reversa. Temin focava seus estudos em retrovírus, o Rous sarcoma vírus (RSV), capaz de transformar células normais em células tumorais. Temin propôs que o mecanismo de transformação do RSV seria a conversão do seu material genético RNA em DNA e comprovou que o mecanismo de transformação de células normais em tumorais era bloqueado por inibidores da síntese de DNA. Tal hipótese foi confirmada por outro pesquisador, David Baltimore, na mesma época que conseguiu isolar a enzima transcriptase reversa do vírus de leucemia murina Rauscher (R-MLV). Temin e Baltimore receberam o Prêmio Nobel de Fisiologia e Medicina, em 1975, pela descoberta da transcriptase reversa1. Tal descoberta promove continuamente o desenvolvimento de inúmeras técnicas para pesquisas em saúde e avanço nas áreas de investigação clínica e precisão no diagnóstico e tratamento de doenças. Este artigo tem como objetivo revisar os princípios e atualidades da tecnologia de amplificação por tempo real e suas importantes aplicações em medicina.