Caspase-3-dependent cleavage of Bcl-xL in the stroma exosomes is required for their uptake by hematological malignant cells

Therapeutically Harnessing Tumor Cell-Derived Extracellular Vesicles for Multiple Myeloma: Recent Advances and Future Perspectives

Extracellular vesicles (EVs) have emerged as pivotal regulators for extensive intercellular crosstalk owing to capsuled diverse bioactive substances such as proteins, nucleic acids, and lipids. Recent studies have shown that tumor-derived EVs significantly influence the bone marrow microenvironment, contributing to the progression of multiple myeloma (MM). This highlights the robust potential of EVs as a promising avenue for developing more effective and precise diagnostic and therapeutic strategies for MM. In this review, we briefly discuss the multifaceted roles of EVs in MM progression, as well as the diagnostic and therapeutic value in MM management. Specifically, we focus on the latest research progress regarding the therapeutic potential of EVs for MM, particularly tumor cell-derived EVs, as we elaborate on three main aspects: (i) EVs as therapeutic targets, including the targeted inhibition of EV biogenesis and uptake, and the possibility of eliminating tumor-derived EVs; (ii) EVs as delivery nanovectors, where we discuss the latest anti-MM candidates and potential ways to optimize therapeutic efficiency; and (iii) engineered EVs as antitumor vaccines, focusing on the use of tumor cell-derived EVs in immunotherapy. Finally, we address the prospects and challenges of harnessing the therapeutic potential of EVs in clinical transformation.

Monitoring Glucocorticoid Receptor in Plasma-derived Extracellular Vesicles as a Marker of Resistance to Androgen Receptor Signaling Inhibition in Prostate Cancer

Disease progression following androgen ablation was shown to be associated with upregulation of the glucocorticoid receptor (GR). Longitudinal monitoring of GR expression in circulating extracellular vesicles (EV) may reflect changes in the tumor cell and facilitates detection of acquired resistance. We utilized LNCaP, LREX cells and a patient-derived xenograft, MDA PDX 322-2-6a, for in vitro and in vivo experiments. Plasma-derived EVs were isolated from patients with localized high-risk prostate cancer undergoing androgen ablation. The mRNA levels of GR in EVs and their responsive genes were detected by transcriptome analysis, qRT-PCR and the protein levels by Western blot analysis. We detected changes in GR expression at mRNA and protein levels in EVs derived from LNCaP and LREX cells in in vitro studies. In in vivo experiments, LNCaP and the PDX MDA 322-2-6a-bearing mice were treated with enzalutamide. GR levels in plasma-derived EVs were increased only in those tumors that did not respond to enzalutamide. Treatment of mice bearing enzalutamide-resistant tumors with a GR inhibitor in combination with enzalutamide led to a transient pause in tumor growth in a subset of tumors and decreased GR levels intracellular and in plasma-derived EVs. In a subgroup of patients with high-risk localized prostate cancer treated with androgen signaling inhibition, GR was found upregulated in matching tissue and plasma EVs. These analyses showed that GR levels in plasma-derived EVs may be used for monitoring the transition of GR expression allowing for early detection of resistance to androgen ablation treatment.

SIGNIFICANCE

Longitudinal monitoring of GR expression in plasma-derived EVs from patients with prostate cancer treated with androgen signaling inhibitors facilitates early detection of acquisition of resistance to androgen receptor signaling inhibition in individual patients.

The Role of Extracellular Vesicles in the Pathogenesis of Hematological Malignancies: Interaction with Tumor Microenvironment; a Potential Biomarker and Targeted Therapy

The tumor microenvironment (TME) plays an important role in the development and progression of hematological malignancies. In recent years, studies have focused on understanding how tumor cells communicate within the TME. In addition to several factors, such as growth factors, cytokines, extracellular matrix (ECM) molecules, etc., a growing body of evidence has indicated that extracellular vesicles (EVs) play a crucial role in the communication of tumor cells within the TME, thereby contributing to the pathogenesis of hematological malignancies. The present review focuses on how EVs derived from tumor cells interact with the cells in the TME, such as immune cells, stromal cells, endothelial cells, and ECM components, and vice versa, in the context of various hematological malignancies. EVs recovered from the body fluids of cancer patients often carry the bioactive molecules of the originating cells and hence can be considered new predictive biomarkers for specific types of cancer, thereby also acting as potential therapeutic targets. Here, we discuss how EVs influence hematological tumor progression via tumor-host crosstalk and their use as biomarkers for hematological malignancies, thereby benefiting the development of potential therapeutic targets.

Caspases help to spread the message via extracellular vesicles

Cell-cell communication is an essential aspect of multicellular life, key for coordinating cell proliferation, growth, and death in response to environmental changes. Whilst caspases are well-known for facilitating apoptotic and pyroptotic cell death, several recent investigations are uncovering new roles for these enzymes in biological scenarios requiring long-range intercellular signalling mediated by extracellular vesicles (EVs). EVs are small membrane-bound nanoparticles released from cells that may carry and deliver cargo between distant cells, thus helping to coordinate their behaviour. Intriguingly, there is emerging evidence indicating a key contribution of caspases in the biogenesis of EVs, the selection of their cargo content, and EV uptake/function in recipient cells. Here, we discuss the latest findings supporting the interplay between caspases and EVs, and the biological relevance of this molecular convergence for cellular signalling, principally in non-apoptotic scenarios.

Exosomes: A new option for osteoporosis treatment

Osteoporosis is a systemic bone disease characterized by reduced bone mass and destruction of bone microarchitecture, leading to increased bone fragility and susceptibility to fracture. However, the pathogenesis and molecular mechanisms of this disease remain unclear. Extracellular vesicles, structures originating from the plasma membrane and ranging from 30 nm to 5 µm in diameter, play an important role in intercellular communication in the bone microenvironment. Exosomes are extracellular vesicles that deliver cargo molecules, including endogenous proteins, lipids and nucleic acids. These cargo molecules are encapsulated in a lipid bilayer and internalized by target cells through receptor-ligand interactions or lipid membrane fusion. With the advancement of exosome research, exosome therapy for osteoporosis is fast becoming a research hotspot for researchers. This review aims to discuss the role of exosomes in the pathogenesis of osteoporosis. In addition, emerging diagnostic and therapeutic properties of exosomes are described to highlight the potential role of exosomes in osteoporosis.

Exosomes in multiple myeloma: from bench to bedside

Multiple myeloma (MM) remains an incurable plasma cell malignancy that develops in the bone marrow (BM). This BM is partially responsible for protecting the MM cells against current standard-of-care therapies and for accommodating MM-related symptoms such as bone resorption and immune suppression. Increasing evidence has implicated extracellular vesicles (EV), including exosomes in the different processes within the BM. Exosomes are <150-nm-sized vesicles secreted by different cell types including MM cells. These vesicles contain protein and RNA cargo that they deliver to the recipient cell. In this way, they have been implicated in MM-related processes including osteolysis, angiogenesis, immune suppression, and drug resistance. Targeting exosome secretion could therefore potentially block these different processes. In this review, we will summarize the current findings of exosome-related processes in the BM and describe not only the current treatment strategies to counter them but also how exosomes can be harnessed to deliver toxic payloads. Finally, an overview of the different clinical studies that investigate EV cargo as potential MM biomarkers in liquid biopsies will be discussed.

Multiple Myeloma Cell-Derived Exosomes: Implications on Tumorigenesis, Diagnosis, Prognosis and Therapeutic Strategies

Multiple myeloma (MM) is a hematological disease that is still not curable. The bone marrow milieu, with cellular and non-cellular elements, participate in the creation of a pro-tumoral environment enhancing growth and survival of MM plasma cells. Exosomes are vesicles oscillating in dimension between 50 nm and 100 nm in size that can be released by various cells and contribute to the pathogenesis and progression of MM. Exosomes enclose proteins, cytokines, lipids, microRNAs, long noncoding RNAs, and circular RNAs able to regulate interactions between MM plasma cells and adjacent cells. Through exosomes, mesenchymal stem cells confer chemoresistance to MM cells, while myeloma cells promote angiogenesis, influence immune response, cause bone lesions, and have an impact on the outcome of MM patients. In this review, we analyze the role played by exosomes in the progression of monoclonal gammopathies and the effects on the proliferation of neoplastic plasma cells, and discuss the possible employment of exosomes as potential targets for the treatment of MM patients.

Apoptosis in platelets from adult patients with chronic idiopathic thrombocytopenic purpura

Adult chronic idiopathic thrombocytopenic purpura (cITP) is a chronic and usually life-long haemorrhagic disorder in which enhanced platelet destruction and weakened platelet production lead to thrombocytopenia. Platelets were isolated from blood samples collected from 40 adult patients with cITP and 40 healthy volunteers. Mitochondrial membrane potential (ΔΨm) and plasma membrane phosphatidylserine externalization were determined by flow cytometry, and activation of caspase-3 and expressions of Bax, Bak and Bcl-xL were analysed by western blotting. Flow cytometry showed increased mitochondrial depolarization and lower ΔΨm in platelets from adult patients with cITP. In addition, plasma membrane phosphatidylserine externalization was observed on platelets from adult patients with cITP, but rarely from healthy volunteers. Western blot analysis of platelet proteins revealed that, in adult cITP patients, caspase-3 was activated, which cleaved gelsolin and to release a 47-kDa fragment. Moreover, the expressions of Bax and Bak were elevated, and Bcl-xL was decreased markedly in platelets from adult patients with cITP. Our findings reveal, based on loss of mitochondrial membrane potential (Δψm), phosphatidylserine exposure, caspase-3 activation, enhanced expression of Bax and Bak, and attenuated expression of Bcl-xL, that platelet death in the pathogenesis of thrombocytopenia in chronic ITP in adults is apoptotic.

The interplay between apoptosis and cellular senescence: Bcl-2 family proteins as targets for cancer therapy

Cell death by apoptosis and permanent cell cycle arrest by senescence serve as barriers to the development of cancer. Chemotherapeutic agents not only induce apoptosis, they can also induce senescence known as therapy-induced senescence (TIS). There are, however, controversies whether TIS improves or worsens therapeutic outcome. Unlike apoptosis, which permanently removes cancer cells, senescent cells are metabolically active, and can contribute to tumor progression and relapse. If senescent cells are not cleared by the immune system or if cancer cells escape senescence, they may acquire resistance to apoptotic stimuli and become highly aggressive. Thus, there have been significant efforts in developing senolytics, drugs that target these pro-survival molecules to eliminate senescent cells. The anti-apoptotic Bcl-2 family proteins not only protect against cell death by apoptosis, but they also allow senescent cells to survive. While combining senolytics with chemotherapeutic drugs is an attractive approach, there are also limitations. Moreover, members of the Bcl-2 family have distinct effects on apoptosis and senescence. The purpose of this review article is to discuss recent literatures on how members of the Bcl-2 family orchestrate the interplay between apoptosis and senescence, and the challenges and progress in targeting these Bcl-2 family proteins for cancer therapy.

Changes in Apoptotic Pathways in MOLM-13 Cell Lines after Induction of Resistance to Hypomethylating Agents

We established the following two variants of the MOLM-13 human acute myeloid leukemia (AML) cell line: (i) MOLM-13/DAC cells are resistant to 5-aza-2′-deoxycytidine (DAC), and (ii) MOLM-13/AZA are resistant to 5-azacytidine (AZA). Both cell variants were obtained through a six-month selection/adaptation procedure with a stepwise increase in the concentration of either DAC or AZA. MOLM-13/DAC cells are resistant to DAC, and MOLM-13/AZA cells are resistant to AZA (approximately 50-fold and 20-fold, respectively), but cross-resistance of MOLM-13/DAC to AZA and of MOLM-13/AZA to DAC was not detected. By measuring the cell retention of fluorescein-linked annexin V and propidium iodide, we showed an apoptotic mode of death for MOLM-13 cells after treatment with either DAC or AZA, for MOLM-13/DAC cells after treatment with AZA, and for MOLM-13/AZA cells after treatment with DAC. When cells progressed to apoptosis, via JC-1 (5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide) assay, we detected a reduction in the mitochondrial membrane potential. Furthermore, we characterized promoter methylation levels for some genes encoding proteins regulating apoptosis and the relation of this methylation to the expression of the respective genes. In addition, we focused on determining the expression levels and activity of intrinsic and extrinsic apoptosis pathway proteins.

Raman Spectroscopic Stratification of Multiple Myeloma Patients Based on Exosome Profiling

Multiple myeloma (MM) is a hematological malignancy characterized by abnormal plasma cell proliferation within the bone marrow which leads to progressive bone marrow failure, skeletal osteolytic lesions, and renal insufficiency, thus severely affecting the quality of life. MM is always preceded by monoclonal gammopathy of uncertain significance (MGUS), which progresses to asymptomatic-MM (aMM) or symptomatic-MM (sMM) at a rate of 1% per year. Despite impressive progress in the therapy of the disease, MM remains incurable. Based on these premises, the identification of biomarkers of MGUS progression to MM is a crucial issue in disease management. In this regard, exosomes (EXs) and their precious biomolecular cargo could play a pivotal role in MM detection, stratification, and follow-up. Raman spectroscopy, a label- and manipulation-free technique, and its enhanced version, surface-enhanced Raman spectroscopy (SERS), have been used for characterizing MGUS, aMM, and sMM patient-derived EXs. Here, we have demonstrated the capability of Raman spectroscopy for discriminating EXs along the progression from MGUS to aMM and sMM, thus providing useful clinical indications for patient care. The used SERS devices, based on random nanostructures, have shown good potential in terms of sensitivity, but further developments are needed for achieving reproducible and quantitative SERS results.

Caspase-3 Cleaves Extracellular Vesicle Proteins During Auditory Brainstem Development

Sound localization requires extremely precise development of auditory brainstem circuits, the molecular mechanisms of which are largely unknown. We previously demonstrated a novel requirement for non-apoptotic activity of the protease caspase-3 in chick auditory brainstem development. Here, we used mass spectrometry to identify proteolytic substrates of caspase-3 during chick auditory brainstem development. These auditory brainstem caspase-3 substrates were enriched for proteins previously shown to be cleaved by caspase-3, especially in non-apoptotic contexts. Functional annotation analysis revealed that our caspase-3 substrates were also enriched for proteins associated with several protein categories, including proteins found in extracellular vesicles (EVs), membrane-bound nanoparticles that function in intercellular communication. The proteome of EVs isolated from the auditory brainstem was highly enriched for our caspase-3 substrates. Additionally, we identified two caspase-3 substrates with known functions in axon guidance, namely Neural Cell Adhesion Molecule (NCAM) and Neuronal-glial Cell Adhesion Molecule (Ng-CAM), that were found in auditory brainstem EVs and expressed in the auditory pathway alongside cleaved caspase-3. Taken together, these data suggest a novel developmental mechanism whereby caspase-3 influences auditory brainstem circuit formation through the proteolytic cleavage of extracellular vesicle (EV) proteins.

Development of Conformational Antibodies to Detect Bcl-xL's Amyloid Aggregates in Metal-Induced Apoptotic Neuroblastoma Cells

Bcl-xL, a member of the Bcl-2 family, is a pro-survival protein involved in apoptosis regulation. We have previously reported the ability of Bcl-xL to form various types of fibers, from native to amyloid conformations. Here, we have mimicked the effect of apoptosis-induced caspase activity on Bcl-xL by limited proteolysis using trypsin. We show that cleaved Bcl-xL (ΔN-Bcl-xL) forms fibers that exhibit the features of amyloid structures (BclxLcf37). Moreover, three monoclonal antibodies (mAbs), produced by mouse immunization and directed against ΔN-Bcl-xL or Bcl-xL fibers, were selected and characterized. Our results show that these mAbs specifically target ΔN-Bcl-xL in amyloid fibers in vitro. Upon metal-stress-induced apoptosis, these mAbs are able to detect the presence of Bcl-xL in amyloid aggregates in neuroblastoma SH-SY5Y cell lines. In conclusion, these specific mAbs directed against amyloidogenic conformations of Bcl-xL constitute promising tools for studying, in vitro and in cellulo, the contribution of Bcl-xL in apoptosis. These mAbs may further help in developing new diagnostics and therapies, considering Bcl-xL as a strategic target for treating brain lesions relevant to stroke and neurodegenerative diseases.

BH3 Mimetics in AML Therapy: Death and Beyond?

B cell lymphoma 2 (BCL2) homology domain 3 (BH3) mimetics are targeted therapeutic agents that allow response prediction and patient stratification. BH3 mimetics are prototypical activators of the mitochondrial death program in cancer. They emerged as important modulators of cellular mechanisms contributing to poor therapeutic responses, including cancer cell stemness, cancer-specific metabolic routes, paracrine signaling to the tumor microenvironment, and immune modulation. We present an overview of the antagonism between BH3 mimetics and antiapoptotic BCL2 proteins. We focus on acute myeloid leukemia (AML), a cancer with reduced therapeutic options that have recently been improved by BH3 mimetics.

Normoxic Tumour Extracellular Vesicles Modulate the Response of Hypoxic Cancer and Stromal Cells to Doxorubicin In Vitro

Extracellular vesicles (EV) secreted in the tumour microenvironment (TME) are emerging as major antagonists of anticancer therapies by orchestrating the therapeutic outcome through altering the behaviour of recipient cells. Recent evidence suggested that chemotherapeutic drugs could be responsible for the EV-mediated tumour-stroma crosstalk associated with cancer cell drug resistance. Here, we investigated the capacity of tumour EV (TEV) secreted by normoxic and hypoxic (1% oxygen) C26 cancer cells after doxorubicin (DOX) treatment to alter the response of naïve C26 cells and RAW 264.7 macrophages to DOX. We observed that C26 cells were less responsive to DOX treatment under normoxia compared to hypoxia, and a minimally cytotoxic DOX concentration that mounted distinct effects on cell viability was selected for TEV harvesting. Homotypic and heterotypic pretreatment of naïve hypoxic cancer and macrophage-like cells with normoxic DOX-elicited TEV rendered these cells slightly less responsive to DOX treatment. The observed effects were associated with strong hypoxia-inducible factor 1-alpha (HIF-1α) induction and B-cell lymphoma-extra-large anti-apoptotic protein (Bcl-xL)-mediated anti-apoptotic response in normoxic DOX-treated TEV donor cells, being also tightly connected to the DOX-TEV-mediated HIF-1α induction, as well as Bcl-xL levels increasing in recipient cells. Altogether, our results could open new perspectives for investigating the role of chemotherapy-elicited TEV in the colorectal cancer TME and their modulatory actions on promoting drug resistance.

Exosomes derived from chemically induced human hepatic progenitors inhibit oxidative stress induced cell death

The emerging field of regenerative medicine has revealed that the exosome contributes to many aspects of development and disease through intercellular communication between donor and recipient cells. However, the biological functions of exosomes secreted from cells have remained largely unexplored. Here, we report that the human hepatic progenitor cells (CdHs)‐derived exosome (EXO^hCdHs) plays a crucial role in maintaining cell viability. The inhibition of exosome secretion treatment with GW4869 results in the acceleration of reactive oxygen species (ROS) production, thereby causing a decrease of cell viability. This event provokes inhibition of caspase dependent cell death signaling, leading to a ROS‐dependent cell damage response and thus induces promotion of antioxidant gene expression or repair of cell death of hypoxia‐exposed cells. Together, these findings show the effect of exosomes in regeneration of liver cells, and offer valuable new insights into liver regeneration.

Do exosomes play role in cardiovascular disease development in hematological malignancy?

Exosomes play a role in the pathogenesis and treatment of malignancies as a double-edged sword. Recently, researchers discussed about two new roles, cardiomyocyte function impairment and cardiovascular disease (CVD) genesis. Data were collected from PUBMED at various time points up to the 2019 academic year. The related key words are listed as following; "Arsenic trioxide", "acute promyelocytic leukemia" and "cardio toxicity" and "molecular pathway" and "biomarker". This study has shown that exosomes secreted substances stimulate angiogenesis and cardiomyocytes repairment; cited process depended on the kinds of released substances. Generally, exosomes may involve in the pathogenesis of CVD; although CVD can prevented by identifying the pathways that induce angiogenesis.

Cancer-Derived Exosomes: Their Role in Cancer Biology and Biomarker Development

Exosomes are a subset of tiny extracellular vesicles manufactured by all cells and are present in all body fluids. They are produced actively in tumor cells, which are released and utilized to facilitate tumor growth. Their characteristics enable them to assist major cancer hallmarks, leveraged by cancer cells in fostering cancer growth and spread while implementing ways to escape elimination from the host environment. This review updates on the latest progress on the roles of cancer-derived exosomes, of 30-100 nm in size, in deregulating paracrine trafficking in the tumor microenvironment and circulation. Thus, exosomes are being exploited in diagnostic biomarker development, with its potential in clinical applications as therapeutic targets utilized in exosome-based nanoparticle drug delivery strategies for cancer therapy. Ongoing studies were retrieved from PubMed^® and Scopus database and ClinicalTrials.gov registry for review, highlighting how cancer cells from entirely different cell lines rely on genetic information carried by their exosomes for homotypic and heterotypic intercellular communications in the microenvironment to favor proliferation and invasion, while establishing a pre-metastatic niche in welcoming cancer cells' arrival. We will elaborate on the trafficking of tumor-derived exosomes in fostering cancer proliferation, invasion, and metastasis in hematopoietic (leukemia and myeloma), epithelial (breast cancer), and mesenchymal (soft tissue sarcoma and osteosarcoma) cancers. Cancer-derived exosomal trafficking is observed in several types of liquid or solid tumors, confirming their role as cancer hallmark enabler. Their enriched genetic signals arising from their characteristic DNA, RNA, microRNA, and lncRNA, along with specific gene expression profiles, protein, or lipid composition carried by the exosomal cargo shed into blood, saliva, urine, ascites, and cervicovaginal lavage, are being studied as a diagnostic, prognostic, or predictive cancer biomarker. We reveal the latest research efforts in exploiting the use of nanoparticles to improve the overall cancer diagnostic capability in the clinic.

Review of the Application of Nanovesicles and the Human Interstitial Fluid in Gastrointestinal Premalignant Lesion Detection, Diagnosis, Prognosis and Therapy

Premalignant lesions arise from cells that abnormally proliferate and have a tendency to become cancerous. Developing methods to specifically target and remove these premalignant lesions is imperative to the prevention of malignant progression into gastrointestinal (GI) tumors. However, accurate detection and diagnosis of GI precancerous lesions is challenging, as these lesions show little or no structural change. Thus, this prevents early intervention and reduces the success rate of therapy. In this review, we performed a systematic analysis of the technological advancements in the combined application of nanovesicles (NVs) and the human interstitial fluid (HIF) to specifically target GI premalignant lesions. NVs, which include quantum dots (QDs), are small membranous vehicles of a nanometer diameter that are widely used as drug delivery vectors, therapeutic effectors and diagnostic sensors. HIF is the fluid that is present in human interstitial tissues (HITs) in which signaling molecules and agents travel and can be found throughout the body. HIF is exploited by tumor cells for their invasion, migration and spread. Because the HITs span the entire submucosa of the gastrointestinal tract, they have been increasingly targeted in GI tumor therapy. The challenges involved in the combined application of NVs and HIF in the detection, diagnosis, prognosis and therapy of GI premalignant lesions are also discussed.

The opportunistic effect of exosomes on Non-Hodgkin Lymphoma microenvironment modulation

There has been a shift in the paradigm of Non-Hodgkin lymphomas, changing from the classical genetic aberration-based model to a more complex and dynamic model involving tumor microenvironment interactions. In this instance, exosomes have emerged as important mediators in intercellular communication by providing survival and proliferation signals, licensing immune evasion and acquisition of drug resistance. The capability to transfer molecular cargo made exosomes a focus of research to understand cancer pathogenesis and its progression pathways. Several studies identified exosomes transporting tumor-released components in peripheral blood and focused on understanding their clinical relevance in the diagnosis, prognostic and in monitoring cancer progression. Moreover, due to their biophysical properties and physiological function, exosomes have drawn attention as potential therapeutic target and drug delivery vehicles. This review will discuss the function of exosomes in Non-Hodgkin lymphomagenesis, highlight their potential as diagnosis and prognosis biomarkers, and as new therapeutic opportunities in lymphoma management.

Alcohol Exposure Impacts the Composition of HeLa-Derived Extracellular Vesicles

Extracellular vesicles are nanosized vesicles that are under intense investigation for their role in intercellular communication. Extracellular vesicles have begun to be examined for their role in disease protection and their role as disease biomarkers and/or vaccine agents. The goal of this study was to investigate the effects of alcohol exposure on the biogenesis and composition of extracellular vesicles derived from the cervical cancer line, HeLa. The HeLa cells were cultured in exosome-free media and were either mock-treated (control) or treated with 50 mM or 100 mM of alcohol for 24 h and 48 h. Our results demonstrated that alcohol significantly impacts HeLa cell viability and exosome biogenesis/composition. Importantly, our studies demonstrate the critical role of alcohol on HeLa cells, as well as HeLa-derived extracellular vesicle biogenesis and composition. Specifically, these results indicate that alcohol alters extracellular vesicles’ packaging of heat shock proteins and apoptotic proteins. Extracellular vesicles serve as communicators for HeLa cells, as well as biomarkers for the initiation and progression of disease.

The emerging role of exosomes in multiple myeloma

Multiple myeloma (MM), one of the most prevalent hematological malignancies, accounts for approximately 10% of all blood cancers. In spite of the recent advancements in MM therapy, this malignancy of terminally differentiated plasma cells (PCs) continues to remain a hard-to-cure disease due to the emergence of drug resistance and frequent relapses. It is now well-established that the tumor-supportive involvement of the bone marrow microenvironment (BMM) including the cellular and non-cellular elements are the major causes behind treatment failures of MM as well as its main complications such as osteolytic bone loss. Exosomes (EXs) are membranous structures that carry signaling molecules and have recently received a great deal of attention as important mediators of inter-cellular communication in health and disease. EXs involve in the growth and drug resistance of many tumors via delivering their rich contents of bioactive molecules including miRNAs, growth factors, cytokines, signaling molecules, etc. With regard to MM, many studies have reported that EXs are among the main culprits playing key roles in the vicious network within the BMM of these patients. The main producers of EXs that largely contribute to MM pathogenesis are bone marrow stromal cells (BMSCs) as well as MM cells themselves. These cell types produce large amounts of EXs that affect a variety of target cells including natural killer (NK) cells, osteoclasts (OCs) and osteoblasts (OBs) to the advantage of tumor survival and progression. These EXs contain a different profile of proteins and miRNAs from that of EXs obtained from their counterparts in healthy individuals. MM patients exhibit distinguishable elevations in some of their contents such as miR-21, miR-146a, let-7b and miR-18a, while some molecules like miR-15a are markedly downregulated in EXs of MM patients compared to healthy individuals. These findings make EXs desirable biomarkers for early prediction of disease progression and drug resistance in the context of MM. On the other hand, due to the tumor-supportive role of EXs, targeting these structures in parallel to the conventional therapeutic regimens may be a promising approach to a successful anti-MM therapy. In the present work, an extensive review of the literature has been carried out to highlight the recent advances in the field.

Microvesicles of osteoblasts modulate bone marrow mesenchymal stem cell-induced apoptosis to curcumin in myeloid leukemia cells

Microvesicles (MVs) derived from bone marrow niche components have an important role in genetic reprogramming and subsequent drugs induce apoptosis in leukemic cells. Here, we have found that undertreatment of curcumin or daunorubicin, the cross-talk through MVs of KG-1-bone marrow mesenchymal stem cells (BMSCs), significantly downregulates the expression of the survival gene osteopontin (OPN), CXCL-12, IL-6 (interleukin-6), STAT-3, and VCAM-1 (vascular cell adhesion molecule 1) in treated-KG-1 cells as well as exclusively upregulates CXCL-12 in BMSCs. Drug treated-cell populations' MVs of both single cultured osteoblasts (OBs) and cocultured KG-1 + BMSCs + OBs similarly upregulate survival mediators' OPN, CXCL-12, IL-6, STAT-3, and VCAM-1 in treated-KG-1 cells. Likewise, isolated MVs from KG-1 cells or communication between KG-1, BMSCs, and OBs treated by drugs increase the expression of genes OPN, CXCL-12, IL-6, STAT3, and VCAM-1 by OBs. MVs derived from KG-1 + BMSCs + OBs reduce drug-induced apoptosis in KG-1 cells. This suggests MVs-mediated information transfer is a procedure whereby OBs could overcome BMSCs-induced apoptosis in drug-treated-KG-1 cells.

Deletion of a flippase subunit Tmem30a in hematopoietic cells impairs mouse fetal liver erythropoiesis

Transmembrane protein 30A (Tmem30a) is the β-subunit of P4-ATPases which function as flippase that transports aminophospholipids such as phosphatidylserine from the outer to the inner leaflets of the plasma membrane to maintain asymmetric distribution of phospholipids. It has been documented that deficiency of Tmem30a led to exposure of phosphatidylserine. However, the role of Tmem30a in vivo remains largely unknown. Here we found that Vav-Cre-driven conditional deletion of Tmem30a in hematopoietic cells led to embryonic lethality due to severe anemia by embryonic day 16.5. The numbers of erythroid colonies and erythroid cells were decreased in the Tmem30a deficient fetal liver. This was accompanied by increased apoptosis of erythroid cells. Confocal microscopy analysis revealed an increase of localization of erythropoietin receptor to areas of membrane raft microdomains in response to erythropoietin stimulation in Ter119⁻erythroid progenitors, which was impaired in Tmem30a deficient cells. Moreover, erythropoietin receptor (EPOR)-mediated activation of the STAT5 pathway was significantly reduced in Tmem30a deficient fetal liver cells. Consistently, knockdown of TMEM30A in human CD34⁺ cells also impaired erythropoiesis. Our findings demonstrate that Tmem30a plays a critical role in erythropoiesis by regulating the EPOR signaling pathway through the formation of membrane rafts in erythroid cells.

Extracellular vesicles in DLBCL provide abundant clues to aberrant transcriptional programming and genomic alterations

The biological role of extracellular vesicles (EVs) in diffuse large B-cell lymphoma (DLBCL) initiation and progression remains largely unknown. We characterized EVs secreted by 5 DLBCL cell lines, a primary DLBCL tumor, and a normal control B-cell sample, optimized their purification, and analyzed their content. We found that DLBCLs secreted large quantities of CD63, Alix, TSG101, and CD81 EVs, which can be extracted using an ultracentrifugation-based method and traced by their cell of origin surface markers. We also showed that tumor-derived EVs can be exchanged between lymphoma cells, normal tonsillar cells, and HK stromal cells. We then examined the content of EVs, focusing on isolation of high-quality total RNA. We sequenced the total RNA and analyzed the nature of RNA species, including coding and noncoding RNAs. We compared whole-cell and EV-derived RNA composition in benign and malignant B cells and discovered that transcripts from EVs were involved in many critical cellular functions. Finally, we performed mutational analysis and found that mutations detected in EVs exquisitely represented mutations in the cell of origin. These results enhance our understanding and enable future studies of the role that EVs may play in the pathogenesis of DLBCL, particularly with regards to the exchange of genomic information. Current findings open a new strategy for liquid biopsy approaches in disease monitoring.

Decoding the anticancer activity of VO-clioquinol compound: the mechanism of action and cell death pathways in human osteosarcoma cells

Vanadium compounds were studied in recent years by considering them as a representative of a new class of non-platinum metal anticancer drugs. However, a few challenges still remain in the discovery of new molecular targets of these new metallodrugs. Studies on cell signaling pathways related to vanadium compounds have scarcely been reported and so far this information is highly critical for identifying novel targets that play a key role in the antitumor actions of vanadium complexes. This research deals with the alterations in the intracellular signaling pathways promoted by an oxovanadium(iv) complex with the clioquinol (5-chloro-7-iodo-8-quinolinol), VO(CQ)₂, on a human osteosarcoma cell line (MG-63). Herein are reported, for the first time, the antitumor properties of VO(CQ)₂ and the relative abundance of 224 proteins (which are involved in most of the common intracellular pathways) to identify novel targets of the studied complex. Besides, full-length human recombinant AKT1 kinase was produced by using an IVTT system to evaluate the variation of relative tyrosin-phosphorylation levels caused by this compound. The results of the differential protein expression levels reveal several up-regulated proteins such as CASP3, CASP6, CASP7, CASP10, CASP11, Bcl-x, DAPK and down-regulated ones, such as PKB/AKT, DIABLO, among others. Moreover, cell signaling pathways involved in several altered pathways related to the PKC and AP2 family have been identified in both treatments (2.5 and 10 μM) suggesting the crucial antitumoral role of VO(CQ)₂. Finally, it has been demonstrated that this compound (10 μM, 6 h) triggers a decrease of 2-fold in in situ AKT1 expression.

Extracellular Vesicles in Hematological Malignancies: From Biology to Therapy

Extracellular vesicles (EVs) are a heterogeneous group of particles, between 15 nanometers and 10 microns in diameter, released by almost all cell types in physiological and pathological conditions, including tumors. EVs have recently emerged as particularly interesting informative vehicles, so that they could be considered a true "cell biopsy". Indeed, EV cargo, including proteins, lipids, and nucleic acids, generally reflects the nature and status of the origin cells. In some cases, EVs are enriched of peculiar molecular cargo, thus suggesting at least a degree of specific cellular packaging. EVs are identified as important and critical players in intercellular communications in short and long distance interplays. Here, we examine the physiological role of EVs and their activity in cross-talk between bone marrow microenvironment and neoplastic cells in hematological malignancies (HMs). In these diseases, HM EVs can modify tumor and bone marrow microenvironment, making the latter "stronger" in supporting malignancy, inducing drug resistance, and suppressing the immune system. Moreover, EVs are abundant in biologic fluids and protect their molecular cargo against degradation. For these and other "natural" characteristics, EVs could be potential biomarkers in a context of HM liquid biopsy and therapeutic tools. These aspects will be also analyzed in this review.