Desarrollo y evaluación de KIT NAPPA Array para su uso como plataforma de secreening de fármacos

Comunicaciones a congreso

Mastocitosis sistémica y mutación de Kit: frecuencia, grado de afectación de la hematopoyesis y comportamiento clínico y biológico de la enfermedad

Tesis por compendio de publicaciones[ES]La MS es el subtipo más frecuente de mastocitosis del adulto presentando un elevado grado de heterogeneidad en cuanto a su comportamiento y evolución clínica. En la actualidad son muchos los estudios en los que se describe que la mayoría de los pacientes con MS presentan la mutación D816V, e incluso que demuestran la presencia de esta mutación en otras células hematopoyéticas distintas del mastocito, por lo que implícitamente se considera que la mutación D816V de KIT podría ser un requisito indispensable para la manifestación o persistencia de la mastocitosis en la edad adulta. Sin embargo, en el momento de iniciar este trabajo existían también estudios que contradecían esta hipótesis, ya que describían la presencia de la mutación D816V en pequeños porcentajes de pacientes y, nunca identificaban esta mutación en otras líneas hematopoyéticas. Estas discrepancias pueden deberse tanto al tipo de pacientes seleccionados e incluidos en las diferentes series en función de su subtipo diagnóstico, como a diferentes niveles de sensibilidad de los métodos empleados para el análisis de la mutación. Por lo tanto, para esclarecer los mecanismos de la enfermedad sería clave establecer cuál es el porcentaje real de pacientes con MS que presentan esta mutación, determinar en qué momento de la ontogenia ocurre la mutación, si existen otras líneas hematopoyéticas que puedan estar afectadas por ella y con qué frecuencia aparecen, determinando además si la existencia de un patrón diferente de afectación de la hematopoyesis por la mutación de KIT se traduce en un comportamiento clínico distinto de la enfermedad. Este conocimiento permitiría sin duda, comprender mejor la heterogeneidad de la MS desde un punto de vista clínico‐biológico, a la vez que proporcionaría información clave para la estratificación pronóstica de la enfermedad y para un mejor seguimiento, tratamiento y control de la misma.Ante estos antecedentes, en el presente trabajo doctoral hemos planteado como objetivo general determinar con precisión la frecuencia con la que los pacientes con mastocitosis presentan mutación de KIT, el grado de afectación de la hematopoyesis y de las células de la MO por la mutación y su posible correlación con la presencia de la mutación en SP y la evolución clínica de la enfermedad. Para ello, nos hemos propuesto tres objetivos concretos: ‐ Determinar la frecuencia real de las mutaciones de KIT y en especial de la mutación D816V de KIT, en los mastocitos patológicos de pacientes con MS, y conocer el grado de afectación del resto de líneas celulares hematopoyéticas de la MO. ‐ Establecer la frecuencia con la que se detecta la presencia de la mutación D816V de KIT en SP de pacientes con MS y correlacionar el grado de afectación por dicha mutación en SP, con el grado de afectación de la hematopoyesis medular. ‐ Investigar la posibilidad de que la mutación D816V de KIT esté presente en células MSC de MO y determinar el impacto que éste hallazgo pudiera tener en la evolución a medio y largo plazo de la enfermedad

Functional proteomics approaches for high throuput determination of CKIT and small molecules

Comunicaciones a congreso

The proliferation index of specific bone marrow cell compartments from myelodysplastic syndromes is associated with the diagnostic and patient outcome

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Myelodysplastic syndromes (MDS) are clonal stem cell disorders which frequently show a hypercellular dysplastic bone marrow (BM) associated with inefficient hematopoiesis and peripheral cytopenias due to increased apoptosis and maturation blockades. Currently, little is known about the role of cell proliferation in compensating for the BM failure syndrome and in determining patient outcome. Here, we analyzed the proliferation index (PI) of different compartments of BM hematopoietic cells in 106 MDS patients compared to both normal/reactive BM (n = 94) and acute myeloid leukemia (AML; n = 30 cases) using multiparameter flow cytometry. Our results show abnormally increased overall BM proliferation profiles in MDS which significantly differ between early/low-risk and advanced/high-risk cases. Early/low-risk patients showed increased proliferation of non-lymphoid CD34 + precursors, maturing neutrophils and nucleated red blood cells (NRBC), while the PI of these compartments of BM precursors progressively fell below normal values towards AML levels in advanced/high-risk MDS. Decreased proliferation of non-lymphoid CD34 + and NRBC precursors was significantly associated with adverse disease features, shorter overall survival (OS) and transformation to AML, both in the whole series and when low- and high-risk MDS patients were separately considered, the PI of NRBC emerging as the most powerful independent predictor for OS and progression to AML. In conclusion, assessment of the PI of NRBC, and potentially also of other compartments of BM precursors (e.g.: myeloid CD34 + HPC), could significantly contribute to a better management of MDS.This work has been partially supported by the following grants: RTICC RD06/0020/0035 - Fondo Europeo de Desarrollo Regional FEDER) - from the Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain; M.J.-A. was supported by a grant from the Programa Personal Técnico de Apoyo a la Investigación. Ministerio de Ciencia e Innovación - Universidad de Salamanca, Spain.Peer Reviewe

Whole-Exome sequencing reveals recurrent but heterogeneous mutational profiles in sporadic who grade 1 meningiomas

© 2021 González-Tablas, Prieto, Arandia, Jara-Acevedo, Otero, Pascual, Ruíz, Álvarez-Twose, García-Montero, Orfao and Tabernero.Human WHO grade 1 meningiomas are generally considered benign tumors; despite this, they account for ≈50% of all recurrent meningiomas. Currently, limited data exist about the mutational profiles of grade 1 meningiomas and patient outcome. We investigated the genetic variants present in 32 WHO grade 1 meningiomas using whole exome sequencing, and correlated gene mutational profiles with tumor cytogenetics and patient outcome. Overall, WHO grade 1 meningiomas harbored numerous and heterogeneous genetic variants, which most frequently affected the NF2 (47%) gene and to a less extent the PNMA6A (22%), TIGD1 (16%), SMO (13%), PTEN (13%), CREG2 (9%), EEF1A1 (6%), POLR2A (6%), ARID1B (3%), and FAIM3 (3%) genes. Notably, non-synonymous genetic variants of SMO and POLR2A were restricted to diploid meningiomas, whereas NF2 mutations were only found among tumors that showed -22/22q─ (with or without a complex karyotype). Based on NF2 mutations and tumor cytogenetics, four genetic profiles were defined with an impact on patient recurrence-free survival (RFS). These included (1) two good-prognosis tumor subgroups—diploid meningiomas (n=9) and isolated -22/22q─ associated with NF2 mutation (n=7)—with RFS rates at 10 y of 100%; and (2) two subgroups of poor-prognosis meningiomas—isolated -22/22q─ without NF2 mutation (n=3) and tumors with complex karyotypes (n=11)—with a RFS rate at 10 y of 48% (p=0.003). Our results point out the existence of recurrent but heterogeneous mutational profiles in WHO grade 1 meningiomas which have an impact on patient outcome.This work was supported by grants: IBY 17/00002 from IBSAL (Salamanca, Spain), GRS2132/A2020 from Junta de Castilla y León (Spain), and CB16/12/00400 from CIBER-ONC and FONDOS FEDER (Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain)

A simple immunoassay for extracellular vesicle liquid biopsy in microliters of non-processed plasma

Background: Extracellular vesicles (EVs), released by most cell types, provide an excellent source of biomarkers in biological fluids. However, in order to perform validation studies and screenings of patient samples, it is still necessary to develop general techniques permitting rapid handling of small amounts of biological samples from large numbers of donors. Results: Here we describe a method that, using just a few microliters of patient’s plasma, identifies tumour markers exposed on EVs. Studying physico-chemical properties of EVs in solution, we demonstrate that they behave as stable colloidal suspensions and therefore, in immunocapture assays, many of them are unable to interact with a stationary functionalised surface. Using flocculation methods, like those used to destabilize colloids, we demonstrate that cationic polymers increase EV ζ-potential, diameter, and sedimentation coefficient and thus, allow a more efficient capture on antibody-coated surfaces by both ELISA and bead-assisted flow cytometry. These findings led to optimization of a protocol in microtiter plates allowing effective immunocapture of EVs, directly in plasma without previous ultracentrifugation or other EV enrichment. The method, easily adaptable to any laboratory, has been validated using plasma from lung cancer patients in which the epithelial cell marker EpCAM has been detected on EVs. Conclusions: This optimized high throughput, easy to automate, technology allows screening of large numbers of patients to phenotype tumour markers in circulating EVs, breaking barriers for the validation of proposed EV biomarkers and the discovery of new one

Phenotypic profile of expanded NK cells in chronic lymphoproliferative disorders: a surrogate marker for NK-cell clonality

[EN]Currently, the lack of a universal and specific marker of clonality hampers the diagnosis and classification of chronic expansions of natural killer (NK) cells. Here we investigated the utility of flow cytometric detection of aberrant/altered NK-cell phenotypes as a surrogate marker for clonality, in the diagnostic work-up of chronic lymphoproliferative disorders of NK cells (CLPD-NK). For this purpose, a large panel of markers was evaluated by multiparametric flow cytometry on peripheral blood (PB) CD56(low) NK cells from 60 patients, including 23 subjects with predefined clonal (n = 9) and polyclonal (n = 14) CD56(low) NK-cell expansions, and 37 with CLPD-NK of undetermined clonality; also, PB samples from 10 healthy adults were included. Clonality was established using the human androgen receptor (HUMARA) assay. Clonal NK cells were found to show decreased expression of CD7, CD11b and CD38, and higher CD2, CD94 and HLADR levels vs. normal NK cells, together with a restricted repertoire of expression of the CD158a, CD158b and CD161 killer-associated receptors. In turn, NK cells from both clonal and polyclonal CLPD-NK showed similar/overlapping phenotypic profiles, except for high and more homogeneous expression of CD94 and HLADR, which was restricted to clonal CLPD-NK. We conclude that the CD94(hi)/HLADR+ phenotypic profile proved to be a useful surrogate marker for NK-cell clonality.This work has been partially supported by the following grants: FIS 02/1244-FEDER, DTS 15/00119-FEDER, RTICC RD06/0020/0035-FEDER and RTICC RD12/0036/0048-FEDER from the Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain; SA103/03 and SA079U14 from the Consejería de Educación, Junta de Castilla y León, Valladolid, Spain. The research activities of the EuroFlow Consortium were supported by the European Commission (grant STREP EU-FP6, LSHB-CT-2006–018708, entitled ‘Flow cytometry for fast and sensitive diagnosis and follow-up of hematological malignancies’)

Circulating clonotypic B cells in multiple myeloma and monoclonal gammopathy of undetermined significance

This is an open-access paper.The B-cell compartment in which multiple myeloma stem cells reside remains unclear. We investigated the potential presence of mature, surface-membrane immunoglobulin-positive B lymphocytes clonally related to the tumor bone marrow plasma cells among different subsets of peripheral blood B cells from ten patients (7 with multiple myeloma and 3 with monoclonal gammopathies of undetermined significance). The presence of clonotypic immunoglobulin heavy chain gene rearrangements was determined in multiple highly-purified fractions of peripheral blood B-lymphocytes including surface-membrane IgM+ CD27- naïve B-lymphocytes, plus surface-membrane IgG+, IgA+ and IgM+ memory CD27+ B cells, and normal circulating plasma cells, in addition to (mono)clonal plasma cells, by a highly-specific and sensitive allele-specific oligonucleotide polymerase chain reaction directed to the CDR3 sequence of the rearranged IGH gene of tumor plasma cells from individual patients. Our results showed systematic absence of clonotypic rearrangements in all the different B-cell subsets analyzed, including M-compo-nent isotype-matched memory B-lymphocytes, at frequencies <0.03 cells/mL (range: 0.0003-0.08 cells/mL); the only exception were the myeloma plasma cells detected and purified from the peripheral blood of four of the seven myeloma patients. These results indicate that circulating B cells from patients with multiple myeloma and monoclonal gammopathies of undetermined significance are usually devoid of clonotypic B cells while the presence of immunophenotypically aberrant myeloma plasma cells in peripheral blood of myeloma patients is a relatively frequent finding.This work was supported by grants from European Union FP6 STREP MSCNet (N. E06005FF), Cooperative Research Thematic Network on Cancer (RTICs; RTICC RD06/0020/0035-FEDER, RD06/0020/0006, RD12/0036/0048, RD12/0036/0069 and G03/136), Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria Ministerio de Sanidad y Consumo (FIS: PI060339; 02/0905; 01/0089/01-02;PS09/01897, and PI06/0824-FEDER), Asociacion Española Contra el Cancer AECC (GCB120981SAN) and Gerencia Regional de Salud de Castilla y León; Ayuda de Excelencia de Castilla y León, Consejería de Educación (EDU/894/2009, GR37) Junta de Castilla y León, Valladolid, Spain. LST received a CAPES/Ministério da Educação scholarship from the Brazilian Government.Peer Reviewe

Phenotypic profile of expanded NK cells in chronic lymphoproliferative disorders: a surrogate marker for NK-cell clonality

This is an open-access article distributed under the terms of the Creative Commons Attribution License.Currently, the lack of a universal and specific marker of clonality hampers the diagnosis and classification of chronic expansions of natural killer (NK) cells. Here we investigated the utility of flow cytometric detection of aberrant/altered NK-cell phenotypes as a surrogate marker for clonality, in the diagnostic work-up of chronic lymphoproliferative disorders of NK cells (CLPD-NK). For this purpose, a large panel of markers was evaluated by multiparametric flow cytometry on peripheral blood (PB) CD56 NK cells from 60 patients, including 23 subjects with predefined clonal (n = 9) and polyclonal (n = 14) CD56 NK-cell expansions, and 37 with CLPD-NK of undetermined clonality; also, PB samples from 10 healthy adults were included. Clonality was established using the human androgen receptor (HUMARA) assay. Clonal NK cells were found to show decreased expression of CD7, CD11b and CD38, and higher CD2, CD94 and HLADR levels vs. normal NK cells, together with a restricted repertoire of expression of the CD158a, CD158b and CD161 killer-associated receptors. In turn, NK cells from both clonal and polyclonal CLPD-NK showed similar/overlapping phenotypic profiles, except for high and more homogeneous expression of CD94 and HLADR, which was restricted to clonal CLPD-NK. We conclude that the CD94/HLADR phenotypic profile proved to be a useful surrogate marker for NK-cell clonality.This work has been partially supported by the following grants: FIS 02/1244-FEDER, DTS 15/00119-FEDER, RTICC RD06/0020/0035-FEDER and RTICC RD12/0036/0048-FEDER from the Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain; SA103/03 and SA079U14 from the Consejería de Educación, Junta de Castilla y León, Valladolid, Spain. The research activities of the EuroFlow Consortium were supported by the European Commission (grant STREP EU-FP6, LSHB-CT-2006–018708, entitled ‘Flow cytometry for fast and sensitive diagnosis and follow-up of hematological malignancies’).Peer Reviewe

MAPK inhibitors dynamically affect melanoma release of immune NKG2D-ligands, as soluble protein and extracellular vesicle-associated

Metastatic melanoma presents, in many cases, oncogenic mutations in BRAF, a MAPK involved in proliferation of tumour cells. BRAF inhibitors, used as therapy in patients with these mutations, often lead to tumour resistance and, thus, the use of MEK inhibitors was introduced in clinics. BRAFi/MEKi, a combination that has modestly increased overall survival in patients, has been proven to differentially affect immune ligands, such as NKG2D-ligands, in drug-sensitive vs. drug-resistant cells. However, the fact that NKG2D-ligands can be released as soluble molecules or in extracellular vesicles represents an additional level of complexity that has not been explored. Here we demonstrate that inhibition of MAPK using MEKi, and the combination of BRAFi with MEKi in vitro, modulates NKG2D-ligands in BRAF-mutant and WT melanoma cells, together with other NK activating ligands. These observations reinforce a role of the immune system in the generation of resistance to directed therapies and support the potential benefit of MAPK inhibition in combination with immunotherapies. Both soluble and EV-associated NKG2D-ligands, generally decreased in BRAF-mutant melanoma cell supernatants after MAPKi in vitro, replicating cell surface expression. Because potential NKG2D-ligand fluctuation during MAPKi treatment could have different consequences for the immune response, a pilot study to measure NKG2D-ligand variation in plasma or serum from metastatic melanoma patients, at different time points during MAPKi treatment, was performed. Not all NKG2D-ligands were equally detected. Further, EV detection did not parallel soluble protein. Altogether, our data confirm the heterogeneity between melanoma lesions, and suggest testing several NKG2D-ligands and other melanoma antigens in serum, both as soluble or vesicle-released proteins, to help classifying immune competence of patients