Marta Lasa

Universidad de Navarra | UNAV · Division of Gene Therapy and Hepatology

Purpose: The existence of patients with multiple myeloma (MM) and light-chain (AL) amyloidosis who present with a monoclonal gammopathy of undetermined significance (MGUS)-like phenotype has been hypothesized, but methods to identify this subgroup are not standardized and its clinical significance is not properly validated. Patients and methods:...

Background: Within the spectrum of monoclonal gammopathies, there are various subgroups with unique biological and clinical profiles. Namely, the presence of multiple myeloma (MM) and light-chain amyloidosis (AL) pts with MGUS-like phenotype has been hypothesized, but the criteria to identify this subgroup are poorly defined and lack clinical valid...

B ackground: ARI0002h is an academic autologous CAR T-cell product with a 4-1BB co-stimulatory domain and a humanized single chain variable fragment targeting BCMA, which is being tested in the CARTBCMA-HCB-01 clinical trial for patients (pts) with RRMM (NCT04309981). A fractionated infusion of 3x10 6 CAR+ cells (ARI0002h)/kg (10/30/60%) was admini...

Although light-chain amyloidosis (AL) and multiple myeloma (MM) are characterized by tumor plasma cell (PC) expansion in bone marrow (BM), their clinical presentation differs. Previous attempts to identify unique pathogenic mechanisms behind such differences were unsuccessful, but there are no studies investigating the differentiation stage of tumo...

Light chain (AL) amyloidosis is caused by a small B-cell clone producing light chains that form amyloid deposits and cause organ dysfunction. Chemotherapy aims at suppressing the production of the toxic light chain (LC) and restore organ function. However, even complete hematologic response (CR), defined as negative serum and urine immunofixation a...

Introduction: Both anti-apoptosis and pro-survival mechanisms promote myeloma cell growth and proliferation, and B-cell lymphoma-2 (BCL-2) is over-expressed in a subset of myeloma patients (pts). Venetoclax (V; orally administered BCL-2 inhibitor) monotherapy has demonstrated efficacy in RRMM pts with t(11;14) translocation, who represent 15-20% of...

Protein lifespan is regulated by co-translational modification by several enzymes, including methionine aminopeptidases and N-alpha-aminoterminal acetyltransferases. The NatB enzymatic complex is an N-terminal acetyltransferase constituted by two subunits, NAA20 and NAA25, whose interaction is necessary to avoid NAA20 catalytic subunit degradation....

The reason why a few myeloma cells egress from the bone marrow (BM) into peripheral blood (PB) remains unknown. Here, we investigated molecular hallmarks of circulating tumor cells (CTCs) to identify the events leading to myeloma trafficking into the bloodstream. After using next-generation flow to isolate matched CTCs and BM tumor cells from 32 pa...

Alpha-synuclein (aSyn) protein levels are sufficient to drive Parkinson's disease (PD) and other synucleinopathies. Despite the biomedical/therapeutic potential of aSyn protein regulation, little is known about mechanisms that limit/control aSyn levels. Here, we investigate the role of a post-translational modification, N-terminal acetylation, in a...

Early diagnosis and risk stratification are key to improve outcomes in light-chain (AL) amyloidosis. Here we used multidimensional-flow-cytometry (MFC) to characterize bone marrow (BM) plasma cells (PCs) from a series of 166 patients including newly-diagnosed AL amyloidosis (N = 94), MGUS (N = 20) and multiple myeloma (MM, N = 52) vs. healthy adult...

Purpose Knowledge about the mechanism of action (MoA) of monoclonal antibodies (mAb) is required to understand which patients with multiple myeloma (MM) benefit the most from a given mAb, alone or in combination therapy. Although there is considerable research about daratumumab, knowledge about other anti-CD38 mAbs remains scarce. Experimental Des...

Introduction High-throughput sequencing studies have rendered seminal knowledge in monoclonal gammopathies such as multiple myeloma (MM) and Waldenström's macroglobulinemia (WM). Unfortunately, the low incidence of AL amyloidosis and its typically low tumor burden, often masked by a polyclonal plasma cell (PC) background, account for the limited in...

Background: Since survival in AL mainly depends on the extent of organ involvement of patients at presentation, early diagnosis and risk stratification are key to improve patients' outcome. Therefore, together with surrogates of organ involvement, biomarkers identifying patients with MGUS or MM at greater risk of developing AL would be highly valua...

Background: MM and AL are the two most common malignant monoclonal gammopathies. Both diseases result from the accumulation of clonal PCs, but their clinical behavior is significantly different suggesting fundamental differences in disease biology. Previous attempts to identify genetic hallmarks that could explain such differences have been unsucce...

The identification of new targets for systemic therapy of hepatocellular carcinoma (HCC) is an urgent medical need. Recently, we showed that hNatB catalyzes the N-α-terminal acetylation of 15% of the human proteome and that this action is necessary for proper actin cytoskeleton structure and function. In tumors, cytoskeletal changes influence motil...

The advent of immunotherapy in MM urges the need for in-depth knowledge about immune cells towards improved characterization of patients' immune profiles. Based on few studies, TAMs were suggested to be abundant in the MM tumor microenvironment where they promote cell growth and chemoresistance. However, further investigation about TAMs is warrante...

Novel agents have improved outcomes in MM, but prognosis after patients relapse remains poor and new drugs with novel MoA are needed. The breakthrough of immuno-oncology has rendered new therapeutic options, and most recently we reported on EM801, a novel BCMA-TCB that showed remarkably efficacy when used as single agent in primary bone marrow (BM)...

Monoclonal antibodies (mAbs) targeting CD38 are demonstrating remarkable efficacy, particularly when combined with anti-MM agents. Thus, in-depth understanding of the MoA of anti-CD38 mAbs is of utmost importance to design rational treatment combinations. Notably, while there is considerable data about the MoA of Daratumumab, there is virtually no...

Immunoglobulin light-chain amyloidosis (AL) and multiple myeloma (MM) are 2 distinct monoclonal gammopathies that involve the same cellular compartment: clonal plasma cells (PCs). Despite the fact that knowledge about MM PC biology has significantly increased in the last decade, the same does not apply for AL. Here, we used an integrative phenotypi...

Actin stress fibers (SFs) detect and transmit forces to the extracellular matrix through focal adhesions (FAs), and molecules in this pathway determine cellular behavior. Here, we designed two different computational tools to quantify actin SFs and the distribution of actin cytoskeletal proteins within a normalized cellular morphology. Moreover, a...

Protein N-terminal acetylation (Nt-acetylation) is an important mediator of protein function, stability, sorting, and localization. Although the responsible enzymes are thought to be fairly well characterized, the lack of identified in vivo substrates, the occurrence of Nt-acetylation substrates displaying yet uncharacterized N-terminal acetyltrans...

Human Nalpha-acetyltransferase complex B (hNatB) is integrated by hNaa20p (hNAT5/hNAT3) and hNaa25p (hMDM20) proteins. Previous data have shown that this enzymatic complex is implicated in cell cycle progression and carcinogenesis. In yeast this enzyme acetylates peptides composed by methionine and aspartic acid or glutamic acid in their first two...

Constrained amino acids have become very important tools for modern drug discovery research. Phenylalanine is an ­appropriate residue for study, due to its participation in active site recognition. The series of 1-amino-2-phenylcycloalkanecarboxylic acids - cn Phe - constitutes an attractive family of constrained ­analogues of phenylalanine that ca...

All stereoisomers of 1-amino-2-phenylcyclobutanecarboxylic acid—c4Phe—have been synthesized and the series cnPhe has thus been completed. The use of two different strategies based on a cyclization reaction, starting from ethyl isocyanoacetate and dialkyl malonate, respectively, gave both cis-c4Phe and trans-c4Phe in racemic form. HPLC resolution of...

In order to study the influence of the side-chain orientation on the peptide backbone conformation we have synthesised the model dipeptides t-BuCO-l-Pro-(1S,2R)-c6Phe-NHMe and t-BuCO-l-Pro-(1R,2S)-c6Phe-NHMe, incorporating each enantiomer of the trans cyclohexane analogue of phenylalanine (trans-1-amino-2-phenylcyclohexanecarboxylic acid). The orie...

For the first time, all stereoisomers of 1-amino-2-phenylcyclopentanecarboxylic acid—c5Phe—have been synthesised. A Strecker reaction on 2-phenylcyclopentanone and further transformations of each amino nitrile into the amino acid provides cis-c5Phe and trans-c5Phe with high efficiency. A divergent synthetic route was then developed to obtain the ta...

A family of five- and six-coordinate chiral-at-metal ruthenium complexes has been examined as catalysts in the asymmetric cyclopropanation reaction of styrene with ethyl diazoacetate. With complexes 5 and 6, good cis-diastereoselectivity and enantioselectivity up to 74% were observed.Graphical abstractA family of five- and six-coordinate chiral-at-...

This report describes the synthesis and conformational analysis of optically pure dipeptide analogues of aspartame, namely H-(S)-Asp-(1R,2S)-c6Phe-OMe and H-(S)-Asp-(1S,2R)-c6Phe-OMe, in which the Phe residue of aspartame has been replaced by a restricted Phe with a cyclohexane skeleton: 1-amino-2-phenylcyclohexanecarboxylic acid (c6Phe). The dipep...

Different approaches to the synthesis of enantiomerically pure (1R,2S)- and (1S,2R)-1-amino-2-phenylcyclohexanecarboxylic acids (trans-c6Phe) through a racemic pathway followed by semi-preparative HPLC of a racemic precursor have been studied. The complete diastereoselectivity of the Strecker reaction and the high efficiency of the subsequent trans...