Sanchez-Abarca, L.I. (Luis Ignacio)

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2016 - 20182

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    Immune status of high-risk smoldering multiple myeloma patients and its therapeutic modulation under LenDex: a longitudinal analysis
    (American Society of Hematology, 2016) Perez-Simon, J.A. (José Antonio); Hernández-Martín, J. (J.); Bladé, J. (Joan); Vidriales, M.B. (María Belén); Mateos, M.V. (María Victoria); Arriba, F. (Felipe) de; Sanchez-Abarca, L.I. (Luis Ignacio); Esteves, G. (Graça); Hernandez, M.T. (Miguel Teodoro); Rosiñol, L. (Laura); Puig, N. (Noemí); Lahuerta, J.J. (Juan José); Giraldo, P. (P.); Teruel, A.I. (Ana Isabel); Paiva, B. (Bruno); Oriol, A. (Albert); Rubia, J. (Javier) de la; Corchete, L.A. (Luis A.); Prosper-Cardoso, F. (Felipe); Bargay, J. (Joan); Lopez-Corral, L. (Lucia); San-Miguel, J.F. (Jesús F.)
    Persistence of chemoresistant minimal residual disease (MRD) plasma cells (PCs) is associated with inferior survival in multiple myeloma (MM). Thus, characterization of the minor MRD subclone may represent a unique model to understand chemoresistance, but to our knowledge, the phenotypic and genetic features of the MRD subclone have never been investigated. Here, we compared the antigenic profile of MRD vs diagnostic clonal PCs in 40 elderly MM patients enrolled in the GEM2010MAS65 study and showed that the MRD subclone is enriched in cells overexpressing integrins (CD11a/CD11c/CD29/CD49d/CD49e), chemokine receptors (CXCR4), and adhesion molecules (CD44/CD54). Genetic profiling of MRD vs diagnostic PCs was performed in 12 patients; 3 of them showed identical copy number alterations (CNAs), in another 3 cases, MRD clonal PCs displayed all genetic alterations detected at diagnosis plus additional CNAs that emerged at the MRD stage, whereas in the remaining 6 patients, there were CNAs present at diagnosis that were undetectable in MRD clonal PCs, but also a selected number of genetic alterations that became apparent only at the MRD stage. The MRD subclone showed significant downregulation of genes related to protein processing in endoplasmic reticulum, as well as novel deregulated genes such as ALCAM that is prognostically relevant in MM and may identify chemoresistant PCs in vitro. Altogether, our results suggest that therapy-induced clonal selection could be already present at the MRD stage, where chemoresistant PCs show a singular phenotypic signature that may result from the persistence of clones with different genetic and gene expression profiles. This trial was registered at www.clinicaltrials.gov as #NCT01237249.
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    Role of drug transporters in the sensitivity of acute myeloid leukemia to sorafenib
    (Impact Journals, 2018) Rodríguez-Macías, G. (Gabriela); Díez-Martín, J.L. (José L.); Sánchez-Martín, A. (Anabel); Lozano, E. (Elisa); Herraez, E. (Elisa); Sanchez-Abarca, L.I. (Luis Ignacio); Briz, O. (Oscar); Macias, R. (Rocío); Odero, M.D. (Maria Dolores); Marin, J.J.G (Jose J.G.)
    Background: Chemoresistance often limits the success of the pharmacological treatment in acute myeloid leukemia (AML) patients. Although positive results have been obtained with tyrosine kinase inhibitors (TKIs), such as sorafenib, especially in patients with Fms-like tyrosine kinase 3 (FLT3)-positive AML, the success of chemotherapy is very heterogeneous. Here we have investigated in vitro whether the transportome (set of expressed plasma membrane transporters) is involved in the differential response of AML to sorafenib. Methods: The sensitivity to sorafenib-induced cell death (MTT test and anexin V/7-AAD method) was evaluated in five different cell lines: MOLM-13, OCI-AML2, HL-60, HEL and K-562. The transportome was characterized by measuring mRNA using RT-qPCR. Drug uptake/efflux was determined by flow cytometry using specific substrates and inhibitors. Results: The cytostatic response to sorafenib was: MOLM-13>>OCI-AML2>HL60>HEL≈K-562. Regarding efflux pumps, MDR1 was highly expressed in HEL>K562≈MOLM-13, but not in OCI-AML2 and HL-60. BCRP and MPR3 expression was low in all cell lines, whereas MRP4 and MRP5 expression was from moderate to high. Flow cytometry studies demonstrated that MRP4, but not MRP5, was functional. The expression of the organic cation transporter 1 (OCT1), involved in sorafenib uptake, was MOLM-13>OCI-AML2≈HL-60 and non detectable in HEL and K-562. Transfection of HEL cells with OCT1 increased the sensitivity of these cells to sorafenib, whereas inactive genetic variants failed to induce this change. Conclusion: Together with changes in the expression/function of receptors targeted by TKIs, the expression of plasma membrane transporters involved in sorafenib uptake/efflux may affect the response of leukemia cells to this drug.