Friend or foe?

Funding: This research was funded by Fundação para a Ciência e Tecnologia (FCT), PTDC/MECHEM/30315/2017.Multiple myeloma (MM) is one of the most prevalent hematological cancers worldwide, characterized by the clonal expansion of neoplastic plasma cells in the bone marrow (BM). A combination of factors is implicated in disease progression, including BM immune microenvironment changes. Increasing evidence suggests that the disruption of immunological processes responsible for myeloma control ultimately leads to the escape from immune surveillance and resistance to immune effector function, resulting in an active form of myeloma. In fact, one of the hallmarks of MM is the development of a permissive BM milieu that provides a growth advantage to the malignant cells. Consequently, a better understanding of how myeloma cells interact with the BM niche com-partments and disrupt the immune homeostasis is of utmost importance to develop more effective treatments. This review focuses on the most up-to-date knowledge regarding microenvironment-related mechanisms behind MM immune evasion and suppression, as well as promising molecules that are currently under pre-clinical tests targeting immune populations.publishersversionpublishe

Patient-Derived Multiple Myeloma 3D Models for Personalized Medicine—Are We There Yet?

Funding Information: This work was supported by Fundação para a Ciência e a Tecnologia (FCT), research grant number PTDC/MED-ONC/1215/2021/PT. Funding Information: The authors thank FCT and the Champalimaud Foundation for funding. Publisher Copyright: © 2022 by the authors.Despite the wide variety of existing therapies, multiple myeloma (MM) remains a disease with dismal prognosis. Choosing the right treatment for each patient remains one of the major challenges. A new approach being explored is the use of ex vivo models for personalized medicine. Two-dimensional culture or animal models often fail to predict clinical outcomes. Three-dimensional ex vivo models using patients’ bone marrow (BM) cells may better reproduce the complexity and heterogeneity of the BM microenvironment. Here, we review the strengths and limitations of currently existing patient-derived ex vivo three-dimensional MM models. We analyze their biochemical and biophysical properties, molecular and cellular characteristics, as well as their potential for drug testing and identification of disease biomarkers. Furthermore, we discuss the remaining challenges and give some insight on how to achieve a more biomimetic and accurate MM BM model. Overall, there is still a need for standardized culture methods and refined readout techniques. Including both myeloma and other cells of the BM microenvironment in a simple and reproducible three-dimensional scaffold is the key to faithfully mapping and examining the relationship between these players in MM. This will allow a patient-personalized profile, providing a powerful tool for clinical and research applications.publishersversionpublishe

A Path to Higher Yield and Reproducibility Compared to Sucrose Cushion Ultracentrifugation for Extracellular Vesicle Isolation in Multiple Myeloma

Funding Information: The authors express their gratitude to the Electron Microscopy Unit of Instituto Gulbenkian de Ci\u00EAncia (IGC) for the acquisition of the EV images. Additionally, we extend our appreciation to Carolina Pestana MSc for her contribution to the statistical analysis of this study, to the Systems Oncology Research Group (Champalimaud Foundation) for granting access to the required equipment for this study, and to the Champalimaud Foundation for funding. Publisher Copyright: © 2024 by the authors.Small extracellular vesicles (EVs) play a pivotal role in intercellular communication across various physiological and pathological contexts. Despite their growing significance as disease biomarkers and therapeutic targets in biomedical research, the lack of reliable isolation techniques remains challenging. This study characterizes vesicles that were isolated from conditioned culture media (CCM) sourced from three myeloma cell lines (MM.1S, ANBL-6, and ALMC-1), and from the plasma of healthy donors and multiple myeloma patients. We compared the efficacy, reproducibility, and specificity of isolating small EVs using sucrose cushion ultracentrifugation (sUC) vs. ultrafiltration combined with size-exclusion chromatography (UF-SEC). Our results demonstrate that UF-SEC emerges as a more practical, efficient, and consistent method for EV isolation, outperforming sUC in the yield of EV recovery and exhibiting lower variability. Additionally, the comparison of EV characteristics among the three myeloma cell lines revealed distinct biomarker profiles. Finally, our results suggest that HBS associated with Tween 20 improves EV recovery and preservation over PBS. Standardization of small EV isolation methods is imperative, and our comparative evaluation represents a significant step toward achieving this goal.publishersversionpublishe

Boosting immunity against multiple myeloma

Funding: This research was funded by Fundação para a Ciência e Tecnologia (FCT), PTDC/MECHEM/30315/2017 and UIDB/04443/2020Despite the improvement of patient’s outcome obtained by the current use of immunomod-ulatory drugs, proteasome inhibitors or anti-CD38 monoclonal antibodies, multiple myeloma (MM) remains an incurable disease. More recently, the testing in clinical trials of novel drugs such as anti-BCMA CAR-T cells, antibody–drug conjugates or bispecific antibodies broadened the possibility of improving patients’ survival. However, thus far, these treatment strategies have not been able to steadily eliminate all malignant cells, and the aim has been to induce a long-term complete response with minimal residual disease (MRD)-negative status. In this sense, approaches that target not only myeloma cells but also the surrounding microenvironment are promising strategies to achieve a sustained MRD negativity with prolonged survival. This review provides an overview of current and future strategies used for immunomodulation of MM focusing on the impact on bone marrow (BM) immunome.publishersversionpublishe

Medulloblastomas with ELP1 pathogenic variants: A weakly penetrant syndrome with a restricted spectrum in a limited age window

Background: ELP1 pathogenic variants (PV) have been recently identified as the most frequent variants predisposing to Sonic Hedgehog (SHH) medulloblastomas (MB); however, guidelines are still lacking for genetic counseling in this new syndrome. Methods: We retrospectively reviewed clinical and genetic data of a French series of 29 ELP1-mutated MB. Results: All patients developed SHH-MB, with a biallelic inactivation of PTCH1 found in 24 tumors. Other recurrent alterations encompassed the TP53 pathway and activation of MYCN/MYCL signaling. The median age at diagnosis was 7.3 years (range: 3-14). ELP1-mutated MB behave as sporadic cases, with similar distribution within clinical and molecular risk groups and similar outcomes (5 y - OS=86%); no unusual side effect of treatments was noticed. Remarkably, a germline ELP1 PV was identified in all patients with available constitutional DNA (n=26); moreover, all tested familial trio (n=11) revealed that the PVs were inherited. Two of the 26 index cases from the French series had a family history of MB; pedigrees from these patients and from 1 additional Dutch family suggested a weak penetrance. Apart from MB, no cancer was associated with ELP1 PVs; second tumors reported in 4 patients occurred within the irradiation fields, in the usual time-lapse for expected radiotherapy-induced neoplasms. Conclusions: The low penetrance, the "at risk' age window limited to childhood and the narrow tumor spectrum, question the actual benefit of genetic screening in these patients and their family. Our results suggest restricting ELP1 germline sequencing to patients with SHH-MB, depending on the parents"request

Is Circulating DNA and Tumor Cells in Myeloma the Way Forward?

Multiple myeloma (MM) is the second deadliest hematological cancer. Despite the enormous innovation on MM treatment in the last decades, still 48% of patients die within 5 years after diagnosis. MM diagnosis and therapeutic strategy mainly rely on direct bone marrow (BM) assessment. Given the MM heterogeneity, BM biopsies do not accurately reflect the whole disease status, hampering accurate disease prognosis. Moreover, biopsies are painful and invasive procedures, highlighting the need for non-invasive and more accurate source of biomarkers. Liquid biopsies are promising sources of biomarkers that may overcome these limitations. Peripheral blood carries circulating myeloma components that are being extensively explored since the last few years as an alternative to BM aspirates. These include circulating tumor cells (CTC), cell-free DNA (cfDNA), and extracellular vesicles containing miRNA and proteins. The current review summarizes scientific evidence establishing BM as a gold standard for the diagnosis, prognosis, and evaluation of minimal residual disease. We discuss the last advances regarding cfDNA and CTC biomarkers from peripheral blood in patients with MM as well as the statistical validations. This paper addresses the technological hurdles associated with liquid biopsies and examines the missing steps for their inclusion into the clinical practice

Etude de la dégénérescence ovocytaire chez la souris : rôle des caspases et tixicité de l'uranium naturel

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocSudocFranceF

Retinal stem cells in vertebrates: parallels and divergences.

During the development of the nervous system, after a given number of divisions, progenitors exit the cell cycle and differentiate as neurons or glial cells. Some cells however do not obey this general rule and persist in a progenitor state. These cells, called stem cells, have the ability to self-renew and to generate different lineages. Understanding the mechanisms that allow stem cells to "resist" differentiating stimuli is currently one of the most fascinating research areas for biologists. The amphibian and fish retinas, known to contain stem cell populations, have been pioneering models for neural stem cell research. The Xenopus retina enabled the characterization of the genetic processes that occur in the path from a pluripotent stem cell to a committed progenitor to a differentiated neuron. More recently, the discovery that avian and mammalian retinas also contain stem cell populations, has contributed to the definitive view of the adult nervous system of upper vertebrates as a more dynamic and plastic structure than previously thought. This has attracted the attention of clinicians who are attempting to employ stem cells for transplantation into damaged tissue. Research in this area is promising and will represent a key instrument in the fight against blindness and retinal dystrophies. In this review, we will focus primarily on describing the main characteristics of various retinal stem cell populations, highlighting their divergences during evolution, and their potential for retinal cell transplantation. We will also give an overview of the signaling cascades that could modulate their potential and plasticity

Is Circulating DNA and Tumor Cells in Myeloma the Way Forward?

Multiple myeloma (MM) is the second deadliest hematological cancer. Despite the enormous innovation on MM treatment in the last decades, still 48% of patients die within 5 years after diagnosis. MM diagnosis and therapeutic strategy mainly rely on direct bone marrow (BM) assessment. Given the MM heterogeneity, BM biopsies do not accurately reflect the whole disease status, hampering accurate disease prognosis. Moreover, biopsies are painful and invasive procedures, highlighting the need for non-invasive and more accurate source of biomarkers. Liquid biopsies are promising sources of biomarkers that may overcome these limitations. Peripheral blood carries circulating myeloma components that are being extensively explored since the last few years as an alternative to BM aspirates. These include circulating tumor cells (CTC), cell-free DNA (cfDNA), and extracellular vesicles containing miRNA and proteins. The current review summarizes scientific evidence establishing BM as a gold standard for the diagnosis, prognosis, and evaluation of minimal residual disease. We discuss the last advances regarding cfDNA and CTC biomarkers from peripheral blood in patients with MM as well as the statistical validations. This paper addresses the technological hurdles associated with liquid biopsies and examines the missing steps for their inclusion into the clinical practice

Hydrogen plasma treated nanodiamonds lead to an overproduction of hydroxyl radicals and solvated electrons in solution under ionizing radiation

International audienceIn numerous fields of application (environmental remediation, catalysis, nanomedicine), production ofhydroxyl radicals and solvated electrons by nanomaterials is a cornerstone. Through a very sensitive,nanoparticle-compatible, coumarin-based protocol, we quantified hydroxyl radicals in solution whenhydrogenated (H-ND) and oxidized (Ox-ND) detonation nanodiamonds were irradiated by MeV photons.We highlighted a blatant difference between the two surface chemistries as only H-ND led to 50% moreradicals, for irradiation doses and ND concentrations relevant in nanomedicine. For the first time, we alsoquantified solvated electrons after keV irradiation of both suspensions and showed that in the presenceof H-ND, hydroxyl radicals and solvated electrons were available in solution in equivalent and higheramounts than in water only. This asks the question of the mechanisms at stage and beside the negative/positive electron affinity hypothesis usually mentioned, we proposed, as for other nanomaterials, thatinterfacial water could play an essential role in radicals’ production in solution when detonation H-NDare irradiate