NKG2D-CAR memory T cells target pediatric T-cell acute lymphoblastic leukemia in vitro and n vivo but fail to eliminate leukemiai nitiating cells

[Introduction]: Refractory/relapsed pediatric acute leukemia are still clinically challenging and new therapeutic strategies are needed. Interactions between Natural Killer Group 2D (NKG2D) receptor, expressed in cytotoxic immune cells, and its ligands (NKG2DL), which are upregulated in leukemic blasts, are important for anti-leukemia immunosurveillance. Nevertheless, leukemia cells may develop immunoescape strategies as NKG2DL shedding and/or downregulation. [Methods]: In this report, we analyzed the anti-leukemia activity of NKG2D chimeric antigen receptor (CAR) redirected memory (CD45RA-) T cells in vitro and in a murine model of T-cell acute lymphoblastic leukemia (T-ALL). We also explored in vitro how soluble NKG2DL (sNKG2DL) affected NKG2D-CAR T cells’ cytotoxicity and the impact of NKG2D-CAR T cells on Jurkat cells gene expression and in vivo functionality. [Results]: In vitro, we found NKG2D-CAR T cells targeted leukemia cells and showed resistance to the immunosuppressive effects exerted by sNKG2DL. In vivo, NKG2D-CAR T cells controlled T cell leukemia burden and increased survival of the treated mice but failed to cure the animals. After CAR T cell treatment, Jurkat cells upregulated genes related to proliferation, survival and stemness, and in vivo, they exhibited functional properties of leukemia initiating cells. [Discussion]: The data here presented suggest, that, in combination with other therapeutic approaches, NKG2D-CAR T cells could be a novel treatment for pediatric T-ALL.This work was supported by a grant from the Instituto de Salud Carlos III to LF PI21/01049, the II and V awards from UNOENTRECIENMIL Foundation, and a grant from CRIS FOUNDATION to Beat Cancer as part of the projects “Cell therapy based on NKG2D-CAR for pediatric leukemia” and “NKG2D-CAR as treatment for pediatric patients suffering from acute leukemia and juvenile myelomonocytic leukemia”. AF, MI-N, AN-Z and CF have been supported by Personnel research grants from CRIS Foundation to beat cancer. CM has been supported by Personnel PhD student grants from the Instituto de Salud Carlos III (ISCIII), PFIS (FI19/00176). MVG is funded by grant PID2021-123795OB-I00 from the Spanish Ministry of Science and Innovation [Ministerio de Ciencia e Innovación (MCIN)/Agencia Estatal de Investigación (AEI) / 10.13039/501100011033 and European Regional Development Fund (ERDF)-A way of making Europe] and belongs to cancer-Hub CSIC. MI lab is funded by grant PID2020-114148RB-I00 from the Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033,which was in part granted with FEDER funding (EC)

NKG2D-CAR memory T cells target pediatric T-cell acute lymphoblastic leukemia in vitro and in vivo but fail to eliminate leukemia initiating cells

Introduction Refractory/relapsed pediatric acute leukemia are still clinically challenging and new therapeutic strategies are needed. Interactions between Natural Killer Group 2D (NKG2D) receptor, expressed in cytotoxic immune cells, and its ligands (NKG2DL), which are upregulated in leukemic blasts, are important for anti-leukemia immunosurveillance. Nevertheless, leukemia cells may develop immunoescape strategies as NKG2DL shedding and/or downregulation. Methods In this report, we analyzed the anti-leukemia activity of NKG2D chimeric antigen receptor (CAR) redirected memory (CD45RA ⁻ ) T cells in vitro and in a murine model of T-cell acute lymphoblastic leukemia (T-ALL). We also explored in vitro how soluble NKG2DL (sNKG2DL) affected NKG2D-CAR T cells’ cytotoxicity and the impact of NKG2D-CAR T cells on Jurkat cells gene expression and in vivo functionality. Results In vitro , we found NKG2D-CAR T cells targeted leukemia cells and showed resistance to the immunosuppressive effects exerted by sNKG2DL. In vivo , NKG2D-CAR T cells controlled T cell leukemia burden and increased survival of the treated mice but failed to cure the animals. After CAR T cell treatment, Jurkat cells upregulated genes related to proliferation, survival and stemness, and in vivo , they exhibited functional properties of leukemia initiating cells. Discussion The data here presented suggest, that, in combination with other therapeutic approaches, NKG2D-CAR T cells could be a novel treatment for pediatric T-ALL

Cancer-Stem-Cell Phenotype-Guided Discovery of a Microbiota-Inspired Synthetic Compound Targeting NPM1 for Leukemia

The human microbiota plays an important role in human health and disease, through the secretion of metabolites that regulate key biological functions. We propose that microbiota metabolites represent an unexplored chemical space of small drug-like molecules in the search of new hits for drug discovery. Here, we describe the generation of a set of complex chemotypes inspired on selected microbiota metabolites, which have been synthesized using asymmetric organocatalytic reactions. Following a primary screening in CSC models, we identified the novel compound UCM-13369 (4b) whose cytotoxicity was mediated by NPM1. This protein is one of the most frequent mutations of AML, and NPM1-mutated AML is recognized by the WHO as a distinct hematopoietic malignancy. UCM-13369 inhibits NPM1 expression, downregulates the pathway associated with mutant NPM1 C+, and specifically recognizes the C-end DNA-binding domain of NPM1 C+, avoiding the nucleus-cytoplasm translocation involved in the AML tumorological process. The new NPM1 inhibitor triggers apoptosis in AML cell lines and primary cells from AML patients and reduces tumor infiltration in a mouse model of AML with NPM1 C+ mutation. The disclosed phenotype-guided discovery of UCM-13369, a novel small molecule inspired on microbiota metabolites, confirms that CSC death induced by NPM1 inhibition represents a promising therapeutic opportunity for NPM1-mutated AML, a high-mortality disease.This work was supported by grants PID2022-138797OB-I00, PGC2018-096049-B-I00 and PID2021-126663NB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”; grant PID2019-106279RB-I00 funded by MCIN/AEI/10.13039/501100011033; grant PDC2022-133488-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”; grants PI21/00191 and CP19/00140 funded by Instituto de Salud Carlos III; CNIO agreements 2017-2020, 2020-2023 funded by Foundation CRIS contra el Cancer; grants BIO-198 and P18-FR-3487 funded by Junta de Andalucía; VI PPIT program funded by Universidad de Sevilla; and by Ramón Areces Foundation. The authors acknowledge technological support from NMR, mass spectrometry and elemental analysis CAIs (Complutense University of Madrid), Biointeractomicts Platform (cicCartuja, Seville), and the Services at CITIUS (University of Seville). S.A., A.S.-M., I.A.-A. and R.L.G.-A. are grateful to Ministerio de Ciencia e Innovación and Complutense University of Madrid for predoctoral fellowships; M.V.-E. to European Union’s Horizon 2020 for Marie Sklodowska-Curie grant; and P.A.-G. to Fundación Española de Hematología y Hemoterapia for grant. The authors thank Dr. Adrián Velázquez-Campoy at the University of Saragossa for helping in fitting ITC analysis and Prof. Miguel A. De la Rosa at the University of Seville for critical reading of the manuscript.Peer reviewe

Myc-Related Mitochondrial Activity as a Novel Target for Multiple Myeloma

Mitochondria are involved in the development and acquisition of a malignant phenotype in hematological cancers. Recently, their role in the pathogenesis of multiple myeloma (MM) has been suggested to be therapeutically explored. MYC is a master regulator of b-cell malignancies such as multiple myeloma, and its activation is known to deregulate mitochondrial function. We investigated the impact of mitochondrial activity on the distinct entities of the disease and tested the efficacy of the mitochondrial inhibitor, tigecycline, to overcome MM proliferation. COXII expression, COX activity, mitochondrial mass, and mitochondrial membrane potential demonstrated a progressive increase of mitochondrial features as the disease progresses. In vitro and in vivo therapeutic targeting using the mitochondrial inhibitor tigecycline showed promising efficacy and cytotoxicity in monotherapy and combination with the MM frontline treatment bortezomib. Overall, our findings demonstrate how mitochondrial activity emerges in MM transformation and disease progression and the efficacy of therapies targeting these novel vulnerabilities

The Role of RNA-Binding Proteins in Hematological Malignancies

Hematological malignancies comprise a plethora of different neoplasms, such as leukemia, lymphoma, and myeloma, plus a myriad of dysplasia, such as myelodysplastic syndromes or anemias. Despite all the advances in patient care and the development of new therapies, some of these malignancies remain incurable, mainly due to resistance and refractoriness to treatment. Therefore, there is an unmet clinical need to identify new biomarkers and potential therapeutic targets that play a role in treatment resistance and contribute to the poor outcomes of these tumors. RNA-binding proteins (RBPs) are a diverse class of proteins that interact with transcripts and noncoding RNAs and are involved in every step of the post-transcriptional processing of transcripts. Dysregulation of RBPs has been associated with the development of hematological malignancies, making them potential valuable biomarkers and potential therapeutic targets. Although a number of dysregulated RBPs have been identified in hematological malignancies, there is a critical need to understand the biology underlying their contribution to pathology, such as the spatiotemporal context and molecular mechanisms involved. In this review, we emphasize the importance of deciphering the regulatory mechanisms of RBPs to pinpoint novel therapeutic targets that could drive or contribute to hematological malignancy biology

Mechanosensitive Ion Channels: Their Physiological Importance and Potential Key Role in Cancer

Mechanosensitive ion channels comprise a broad group of proteins that sense mechanical extracellular and intracellular changes, translating them into cation influx to adapt and respond to these physical cues. All cells in the organism are mechanosensitive, and these physical cues have proven to have an important role in regulating proliferation, cell fate and differentiation, migration and cellular stress, among other processes. Indeed, the mechanical properties of the extracellular matrix in cancer change drastically due to high cell proliferation and modification of extracellular protein secretion, suggesting an important contribution to tumor cell regulation. In this review, we describe the physiological significance of mechanosensitive ion channels, emphasizing their role in cancer and immunity, and providing compelling proof of the importance of continuing to explore their potential as new therapeutic targets in cancer research