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BACKGROUND: High-dose (HD) chemotherapy followed by autologous blood stem-cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) patients. However, the collection of sufficient peripheral blood stem cell (PBSC) grafts can be challenging, and the question arises whether reinfusion of low-dose grafts will lead to a hematopoietic recovery. METHODS: The hematopoietic recovery of 148 MM patients who underwent HD melphalan chemotherapy and received PBSC transplants with varying CD34+ cells doses (3-4 × 106 [n = 86], 2-2.5 × 106 [n = 53], < 2 × 106 [n = 9] per kg body weight [bw]) was analyzed in this retrospective single-center study. RESULTS: All patients reached hematopoietic reconstitution, even those who received < 2 × 106 CD34+ cells/kg bw. 62 (42%) patients received granulocyte-colony-stimulating factor (G-CSF). The median duration to leukocyte recovery ≥1.0 × 109/L was 12 days in every group. The median duration to platelet recovery ≥20 × 109/L was 11, 13 and 13 days, respectively. In the multivariate analysis, a low number of reinfused CD34+ cells was associated with prolonged time until leukocyte reconstitution (p = 0.010, HR 0.607) and platelet recovery (p < 0.001, HR 0.438). G-CSF support significantly accelerated leukocyte (p < 0.001, HR 16.742) but not platelet reconstitution. CONCLUSION: In conclusion, reinfusion of low- and even very-low-dose PBSC grafts leads to sufficient hematopoietic reconstitution. No severe adverse events were observed during or after HD chemotherapy and ASCT in the analyzed cohort. While the impact of CD34+ cell dose is marginal, G-CSF significantly accelerates the leukocyte recovery.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Movilización de Célula Madre Hematopoyética/métodos , Células Madre Hematopoyéticas/citología , Mieloma Múltiple/terapia , Trasplante de Células Madre de Sangre Periférica/mortalidad , Células Madre de Sangre Periférica/citología , Adulto , Anciano , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/patología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Trasplante AutólogoRESUMEN
Despite the arrival of novel therapies, multiple myeloma (MM) remains incurable and new treatment options are needed. Chimeric antigen receptor (CAR) T cells are genetically modified T cells that express a CAR directed against specific tumour antigens. CAR T cells are able to kill target tumour cells and may result in long-lasting immune responses in vivo. The rapid development of CAR technologies has led to clinical trials in haematological cancers including MM, and CAR T cells might evolve into a standard treatment in the next few years. Only small patient cohorts with relapsed or refractory disease have so far been investigated, but promising preliminary results with high response rates have been obtained in phase I clinical trials with B cell maturation antigen (BCMA), CD19, CD38 and κ-light-chain CAR T cells. Additional preclinical studies on CD38 and SLAMF7-CAR T cells in MM treatment yielded preclinical results that merit further investigation. Beyond the T cell approach, recent studies have focussed on CAR natural killer (NK) cells in order to increase the reactivity of these effector cells. Finally, to investigate the targeting of intracellular antigens, cellular therapies based on engineered T cell receptors (TCRs) are in development. In this review, we discuss results from preclinical and early-phase clinical trials testing the feasibility and safety of CAR T cell administration in MM, as well as early studies into approaches that utilise CAR NK cell and genetically modified TCRs.
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Inmunoterapia Adoptiva/tendencias , Inmunoterapia , Mieloma Múltiple/terapia , Receptores de Antígenos de Linfocitos T/uso terapéutico , ADP-Ribosil Ciclasa 1/genética , Antígenos de Neoplasias/inmunología , Humanos , Mieloma Múltiple/genética , Mieloma Múltiple/inmunología , Receptores de Antígenos de Linfocitos T/genética , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/genética , Linfocitos T/inmunologíaRESUMEN
Low levels of peripheral blood natural killer T (NKT) cells in cancer patients and a favorable outcome associated with a high number of tumor-infiltrating NKT cells demonstrated in several studies indicated the important role of these immune cells in the antitumor response. With effective antitumor immunity via direct tumor lysis, cytokine modulation of effector cells and regulation of immunosuppressive cells, type I NKT cells display interesting features/properties for the rapidly developing chimeric antigen receptor (CAR) technology. Due to their restriction to the monomorphic HLA-like molecule CD1d, but not to the polymorphic human leukocyte antigen (HLA), NKT CAR cells show potential for enabling autologous and allogeneic/off-the-shelf cancer immunotherapy. Promising results were obtained in preclinical NKT CAR cell studies, but clinical trials have not yet been conducted. In this review, we summarize the biological features of NKT cells, their role in antitumor immunity and recent advances in the development of NKT CAR cells.
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Inmunoterapia Adoptiva , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores Quiméricos de Antígenos/metabolismo , Animales , Biomarcadores , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Humanos , Inmunoterapia Adoptiva/métodos , Células T Asesinas Naturales/citología , Fenotipo , Receptores de Antígenos de Linfocitos T/genética , Receptores Quiméricos de Antígenos/genéticaRESUMEN
OBJECTIVE: Although not the gold standard, contrast-enhanced CT of neck, thorax, and abdomen/pelvis is routinely performed in diagnosis and response assessment of DLBCL. PD during first-line treatment is a relatively rare event. The question arises if the imaging of initially involved regions only might be sufficient for response evaluation. METHOD: We retrospectively analyzed the data of 167 DLBCL patients who had an extensive contrast-enhanced CT scan at first diagnosis. The majority of patients (n = 128, 77%) was treated with R-CHOP. Therapy response was assessed as interim and end of treatment staging by contrast-enhanced CT. RESULTS: The overall response rate at the end of treatment was 94%. None of the patients showed involvement of new sites at interim staging. As a major finding, none of the patients showed an involvement of sites, which were not initially involved. Four patients developed PD during first-line chemotherapy/after mid-treatment staging and 31 relapsed. A conclusive comparison between initial and PD/relapse DLBCL involvement was possible in 27 patients: 8 patients did and 19 patients did not show additional/new sites of involvement compared to first diagnosis. CONCLUSION: Our retrospective analysis provides a rationale for selective imaging of initially involved DLBCL sites for therapy response assessment.
RESUMEN
OBJECTIVES: In patients with Ewing sarcoma and some distinct subgroups of soft tissue sarcoma (STS), a quantitatively sufficient autologous peripheral blood stem cell (PBSC) collection for stem cell support might facilitate treatment continuation, dose-intensification, and high-dose chemotherapy. Here, we provide a detailed evaluation of PBSC collection upon vincristine, ifosfamide, doxorubicin, and etoposide (VIDE) chemomobilization. METHODS: Mobilization and collection parameters of 42 sarcoma patients (Ewing sarcoma n = 35, other STS n = 7) were analyzed retrospectively. Data were evaluated with regard to the number of previous VIDE therapy cycles. RESULTS: All patients reached the collection goal of ≥2.0 × 106 CD34+ cells/kg body weight (bw) upon VIDE/G-CSF mobilization, in the majority of cases with one single leukapheresis (LP) session (n = 29, 69%). No significant differences were identified with regard to mobilization and collection variables or the number of previous induction VIDE therapy cycles. However, upon 5 cycles of VIDE, we found the highest relative proportion of patients who required two or three LP sessions. CONCLUSIONS: Our data demonstrate the feasibility of successful PBSC collection upon VIDE chemomobilization even after up to five cycles of induction therapy, while at the same time the increasing risk of bone marrow exhaustion with every consecutive cycle is outlined.
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Separación Celular , Movilización de Célula Madre Hematopoyética , Trasplante de Células Madre Hematopoyéticas , Células Madre de Sangre Periférica/citología , Sarcoma de Ewing/terapia , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Separación Celular/métodos , Doxorrubicina/administración & dosificación , Etopósido/administración & dosificación , Femenino , Movilización de Célula Madre Hematopoyética/métodos , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Ifosfamida/administración & dosificación , Masculino , Persona de Mediana Edad , Vincristina/administración & dosificación , Adulto JovenRESUMEN
In patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL), R-DHAP (rituximab, dexamethasone, cytarabine, and cisplatin) is a commonly used regimen for salvage therapy and for mobilization of peripheral blood stem cells (PBSCs). At our center, a modified R-DHAP regimen with administration of 25 mg/m(2) cisplatin as a 3-hour infusion over 4 consecutive days, instead of a single infusion of 100 mg/m(2) over 24 hours, has been established. The aim of this study was to analyze the efficiency of this modified R-DHAP regimen plus G-CSF as a mobilization strategy. We retrospectively analyzed clinical characteristics, PBSC collection and autologous stem cell transplantation parameters, and hematologic reconstitution data for 65 patients with relapsed or refractory DLBCL who underwent PBSC collection after mobilization with the modified R-DHAP protocol at our institution between 2002 and 2013. Data were evaluated for the overall cohort and with regard to the number of R-DHAP cycles received before PBSC collection. PBSC collection was performed after the first R-DHAP course in 32 patients (49%), after the second course in 30 patients (46%), and after the third course in 3 patients (5%). Sixty-three patients (97%) achieved the collection goal of ≥2.0 × 10(6) CD34(+) cells/kg body weight. A significantly higher median CD34(+) cell collection yield was achieved when cells were collected after the first R-DHAP course compared with after the second course (P < .01). A peripheral blood leukocyte increase of ≥1.0 × 10(9)/L and a platelet increase of ≥20 × 10(9)/L were observed by 11 days after ASCT. In our cohort, the modified R-DHAP regimen proved safe and feasible, showed an overall response rate (complete response, complete response unconfirmed, and partial response) of 66%, and allowed efficient mobilization of CD34(+) cells for PBSC collection.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cisplatino/administración & dosificación , Movilización de Célula Madre Hematopoyética/métodos , Linfoma de Células B Grandes Difuso/terapia , Adulto , Anciano , Antígenos CD34/análisis , Cisplatino/uso terapéutico , Citarabina/administración & dosificación , Dexametasona/administración & dosificación , Femenino , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Rituximab/administración & dosificación , Terapia Recuperativa/métodos , Trasplante Autólogo , Adulto JovenRESUMEN
Process C (internal clock) and Process S (sleep-wake homeostasis) are the basis of sleep-wake regulation. In the last trimester of pregnancy, foetal heart rate is synchronized with the maternal circadian rhythm. At birth, this interaction fails and an ultradian rhythm appears. Light exposure is a strong factor influencing the synchronization of sleep-wake processes. However, little is known about the effects of phototherapy on the sleep rhythm of premature babies. It was hypothesized that sleep in preterm infants would not differ during phototherapy, but that a maturation effect would be seen. Sleep states were studied in 38 infants born < 32 weeks gestational age and/or < 1 500 g birth weight. Videos of 3 h were taken over the first 5 days of life. Based on breathing and movement patterns, behavioural states were defined as: awake; active sleep; or quiet sleep. Videos with and without phototherapy were compared for amounts of quiet sleep and active states (awake + active sleep). No significant association between phototherapy and amount of quiet sleep was found (P = 0.083). Analysis of videos in infants not under phototherapy revealed an increase in time spent awake with increasing gestational age. The current data suggest that the ultradian rhythm of preterm infants seems to be independent of phototherapy, supporting the notion that sleep rhythm in this population is mainly driven by their internal clock.
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Recien Nacido Extremadamente Prematuro/fisiología , Fototerapia , Sueño/fisiología , Sueño/efectos de la radiación , Peso al Nacer , Femenino , Edad Gestacional , Humanos , Recién Nacido , Movimiento , Embarazo , Respiración , Sueño REM/fisiología , Sueño REM/efectos de la radiación , Ritmo Ultradiano/fisiología , Ritmo Ultradiano/efectos de la radiación , Grabación en Video , Vigilia/fisiología , Vigilia/efectos de la radiaciónRESUMEN
OBJECTIVES: Pertussis and influenza are endemic infections and associated with relevant morbidity and mortality in newborns and young infants. The Swiss Federal Office of Public Health has recommended influenza vaccination since 2011 and pertussis vaccination in pregnancy (ViP) since 2013 and expanded to repetition in each pregnancy since 2017. ViP is safe and effective in preventing severe diseases, but implementation is a challenge. We hypothesized that the proportion of women receiving ViP is persistently low despite existing national recommendations. Our primary objective was to compare the proportion of pertussis and influenza vaccine recommendations for and its acceptance by pregnant women before and after an information campaign tailored to obstetricians. Secondly, we aimed to identify reasons for missing or declining ViP. STUDY DESIGN: We conducted a prospective, single-center, single-arm implementation study in the maternity ward at the University Women's Hospital Basel. We performed standardized interviews with women hospitalized for postpartum care before (October to December 2019, Phase 1, n = 262) and after an information campaign (October to December 2020, Phase 2, n = 233) and compared categorical variables using chi-squared or Fisher's exact test and continuous variables using Whitney Mann U test. RESULTS: We found no significant differences in the proportion of recommendation for pertussis ViP (80 % vs. 84 %, p = 0.25) and implementation (76 % vs. 78 %, p = 0.63) between Phase 1 and 2. Main reasons for missing or declining vaccinations were lack of recommendation (62.8 %) and safety concerns regarding the unborn child (17.7 %). In contrast, the proportion of recommendation for influenza ViP (45 % vs. 63 %, p < 0.001) and implementation (29 % vs. 43 %, p < 0.001) increased significantly. CONCLUSION: Proactive recommendations by obstetricians play a key role in the implementation of ViP but is still insufficient in our setting. We believe that future efforts should aim to explore possible hurdles that impede recommendations by obstetricians for ViP. The focus should be on the needs and experiences of obstetricians in private practice, but also other health care professionals involved in care of pregnant women. Local campaigns do not seem effective enough, therefore national campaigns with new strategies are desirable.
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Vacunas contra la Influenza , Gripe Humana , Complicaciones Infecciosas del Embarazo , Tos Ferina , Recién Nacido , Lactante , Femenino , Embarazo , Humanos , Mujeres Embarazadas , Tos Ferina/prevención & control , Gripe Humana/prevención & control , Estudios Prospectivos , Vacuna contra la Tos Ferina , Aceptación de la Atención de Salud , Encuestas y Cuestionarios , Vacunación , Vacunas contra la Influenza/uso terapéutico , Complicaciones Infecciosas del Embarazo/prevención & controlAsunto(s)
Hepatitis C Crónica/complicaciones , Linfoma de Células B Grandes Difuso/etiología , Carga Viral , Viremia/complicaciones , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antivirales/uso terapéutico , Femenino , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Humanos , Estimación de Kaplan-Meier , Linfoma Folicular/etiología , Linfoma Folicular/mortalidad , Linfoma Folicular/virología , Linfoma de Células B Grandes Difuso/mortalidad , Linfoma de Células B Grandes Difuso/terapia , Linfoma de Células B Grandes Difuso/virología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Adulto JovenAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfoma de Burkitt/tratamiento farmacológico , Inmunoterapia , Terapia Recuperativa , Adolescente , Adulto , Anciano , Trasplante de Médula Ósea , Linfoma de Burkitt/mortalidad , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Insuficiencia del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: Recognition of neuroendocrine differentiation is important for tumor classification and treatment stratification. To detect and confirm neuroendocrine differentiation, a combination of morphology and immunohistochemistry is often required. In this regard, synaptophysin, chromogranin A, and CD56 are established immunohistochemical markers. Insulinoma-associated protein 1 (INSM1) has been suggested as a novel stand-alone marker with the potential to replace the current standard panel. In this study, we compared the sensitivity and specificity of INSM1 and established markers. MATERIALS AND METHODS: A cohort of 493 lung tumors including 112 typical, 39 atypical carcinoids, 77 large cell neuroendocrine carcinomas, 144 small cell lung cancers, 30 thoracic paragangliomas, 47 adenocarcinomas, and 44 squamous cell carcinomas were selected and tissue microarrays were constructed. Synaptophysin, chromogranin A, CD56, and INSM1 were stained on all cases and evaluated manually as well as with an analysis software. Positivity was defined as ≥1% stained tumor cells in at least 1 of 2 cores per patient. RESULTS: INSM1 was positive in 305 of 402 tumors with expected neuroendocrine differentiation (typical and atypical carcinoids, large cell neuroendocrine carcinomas, small cell lung cancers, and paraganglioma; sensitivity: 76%). INSM1 was negative in all but 1 of 91 analyzed non-neuroendocrine tumors (adenocarcinomas, squamous cell carcinomas; specificity: 99%). All conventional markers, as well as their combination, had a higher sensitivity (97%) and a lower specificity (78%) for neuroendocrine differentiation compared with INSM1. CONCLUSIONS: Although INSM1 might be a meaningful adjunct in the differential diagnosis of neuroendocrine neoplasias, a general uncritical vote for replacing the traditional markers by INSM1 may not be justified.
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Antígeno CD56/biosíntesis , Cromogranina A/biosíntesis , Proteínas de Neoplasias/biosíntesis , Proteínas Represoras/biosíntesis , Sinaptofisina/biosíntesis , Neoplasias Torácicas , Femenino , Humanos , Masculino , Neoplasias Torácicas/diagnóstico , Neoplasias Torácicas/metabolismo , Neoplasias Torácicas/patologíaRESUMEN
Histological subtyping of non-small cell lung cancer (NSCLC) is of utmost importance for therapy stratification. Common immunohistochemical markers to identify squamous lineage are CK5/6, p40, and p63. Although p40 is considered the gold standard by current guidelines, the agreement of all three markers is an important aspect for tumours more difficult to classify. A total of 1244 NSCLC including 569 squamous cell carcinomas (SqCC) and 675 adenocarcinomas were assembled on a tissue microarray and stained with CK5/6, p40, p63, TTF-1, and Napsin-A. Sensitivity and specificity for squamous lineage markers as well as agreement of CK5/6, p40 and p63 were calculated. Sensitivity of CK5/6, p40, and p63 for SqCC was 93%, 94%, and 94% and specificity was 98%, 97%, and 84%, respectively. Positivity for two of these markers was found in at least in 90% of SqCC. Highest agreement was observed for p40 and p63 (Cohen's kappa 0.80). We report a similar sensitivity of CK5/6, p40, and p63, but a decreased specificity of p63 as compared to CK5/6 and p40 for the identification of squamous lineage. Our results support the use of either CK5/6 or p40 over p63 in the routine diagnostic setting.
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Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Queratina-5/metabolismo , Neoplasias Pulmonares/diagnóstico , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Malignant lymphoma is still the leading cause of death among AIDS-related diseases. PATIENTS AND METHODS: We performed a retrospective analysis of 50 HIV-positive lymphoma patients. The median interval between HIV and malignant lymphoma diagnosis was 4 years. Eight patients (16%) had Hodgkin lymphoma and 42 (84%) non-Hodgkin lymphoma. Among non-Hodgkin lymphoma patients, diffuse large B-cell lymphoma (n = 18, 42%), Burkitt lymphoma (n = 11, 26%), and plasmoblastic lymphoma (n = 5, 12%) were the most frequent entities. RESULTS: Lymphoma was treated according to standard protocols. Forty-four patients (88%) received combination antiretroviral therapy, 2 (4%) were not treated, and in 4 (8%) the HIV treatment status was not clarified. Response to first-line therapy was complete response (CR) in 24 (56%), partial response (PR) in 15 (35%), and stable disease in 1 (2%). Three patients (7%) developed progressive disease, and 9 (18%) experienced relapse after CR or PR. At a median observation period of 31 (range, 0.4-192) months, the 1-, 2-, and 5-year overall survival was 87%, 79%, and 76%, respectively. At univariate analysis, remission status after first-line treatment was predictive of outcome, as the 2-year overall survival was 95%, 66%, and 0 for patients with CR, with PR, and with progressive disease (P < .001). Results of the multivariate analysis revealed lactate dehydrogenase concentration at lymphoma diagnosis (P = .046) and relapse (P = .050) to be independent factors for overall survival. CONCLUSION: First-line treatment of lymphoma in HIV positive patients is crucial. Patients who experienced and maintained a first CR had a favorable prognosis.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Antivirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Linfoma Relacionado con SIDA/tratamiento farmacológico , Adolescente , Adulto , Anciano , Niño , Preescolar , Quimioterapia Combinada , Femenino , Infecciones por VIH/complicaciones , Humanos , Lactante , Recién Nacido , Estimación de Kaplan-Meier , Linfoma Relacionado con SIDA/complicaciones , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Pronóstico , Inducción de Remisión , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND: In matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) standardized sample preparation is important to obtain reliable results. Herein, the impact of section thickness in formalin-fixed paraffin embedded (FFPE) tissue microarrays (TMA) on spectral intensities is investigated. PATIENTS AND METHODS: TMAs consisting of ten different tissues represented by duplicates of ten patients (n = 200 cores) are cut at 1, 3, and 5 µm. MSI analysis is performed and mean intensities of all evaluable cores are extracted. Measurements are merged and mean m/z intensities are compared. RESULTS: Visual inspection of spectral intensities between 1, 3, and 5 µm reveals generally higher intensities in thinner tissue sections. Specifically, higher intensities are observed in the vast majority of peaks (98.6%, p < 0.01) in 1 µm compared with 5 µm sections. Note that 28.4% and 2.1% of m/z values exhibit a at least two- and threefold intensity difference (p < 0.01) in 1 µm compared to 5 µm sections, respectively. CONCLUSION: A section thickness of 1 µm results in higher spectral intensities compared with 5 µm. The results highlight the importance of standardized protocols in light of recent efforts to identify clinically relevant biomarkers using MSI. The use of TMAs for comparative analysis seems advantageous, as section thickness displays less variability.
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Formaldehído , Imagen Molecular , Adhesión en Parafina , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Análisis de Matrices Tisulares/métodos , Fijación del Tejido , HumanosRESUMEN
Cytotoxic ribonucleases such as the leopard frog derivative Ranpirnase (Onconase(®)) have emerged as a valuable new class of cancer therapeutics. Clinical trials employing single agent Ranpirnase in cancer patients have demonstrated significant clinical activity and surprisingly low immunogenicity. However, dose-limiting toxicity due to unspecific uptake of the RNase into non-cancerous cells is reached at relatively low concentrations of > 1 mg/m(2). We have in the present study generated a dimeric anti-EGFR Ranpirnase-diabody fusion protein capable to deliver two Ranpirnase moieties per molecule to EGFR-positive tumour cells. We show that this compound mediated far superior efficacy for killing EGFR-positive tumour cells than a monomeric counterpart. Most importantly, cell killing was restricted to EGFR-positive target cells and no dose-limiting toxicity of Ranpirnase-diabody was observed in mice. These data indicate that by targeted delivery of Ranpirnase non-selective toxicity can be abolished and suggests Ranpirnase-diabody as a promising new drug for therapeutic interventions in EGFR-positive cancers.
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Antineoplásicos/farmacología , Carcinoma de Células Escamosas/tratamiento farmacológico , Receptores ErbB/metabolismo , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Proteínas Recombinantes de Fusión/farmacología , Ribonucleasas/farmacología , Animales , Carcinoma de Células Escamosas/enzimología , Línea Celular Tumoral , Supervivencia sin Enfermedad , Femenino , Neoplasias de Cabeza y Cuello/enzimología , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Ribonucleasas/genética , Carcinoma de Células Escamosas de Cabeza y Cuello , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Due to its frequent overexpression in a variety of solid tumors the epidermal growth factor receptor (EGFR) is a well-established target for therapeutic interventions in epithelial cancers. In order to target EGFR in head and neck cancer, we have generated a ribonuclease (RNase) fusion protein comprising a humanized anti-EGFR antibody single-chain Fv fragment (scFv) and Ranpirnase, an RNase from Rana pipiens. Fusion of Ranpirnase to the N-terminus of the scFv via a flexible glycine-serine linker (G4S)3 resulted in very poor cytotoxicity of the fusion protein. As endosomal accumulation and lysosomal degradation have been reported to diminish the antitumor efficacy of ribonuclease or toxin-based immunoagents, we explored a fusion peptide from dengue virus that has been reported to be involved in the endosomal escape of the virus. This peptide was introduced as a linker between Ranpirnase and the scFv moiety. The modified immunoRNase exhibited exceptionally high cytotoxicity toward EGFR-expressing head and neck cell lines without affecting specificity. These results indicate that endosomal entrapment needs to be considered for Ranpirnase-based immunoagents and might be overcome by the use of tailored transduction domains from viral proteins.