MiR-16 regulates crosstalk in NF-κB tolerogenic inflammatory signaling between myeloma cells and bone marrow macrophages

Multiple Myeloma Derived Extracellular Vesicle Uptake by Monocyte Cells Stimulates IL-6 and MMP-9 Secretion and Promotes Cancer Cell Migration and Proliferation

Multiple Myeloma (MM) is an incurable haematological malignancy caused by uncontrolled growth of plasma cells. MM pathogenesis is attributed to crosstalk between plasma cells and the bone marrow microenvironment, where extracellular vesicles (EVs) play a role. In this study, EVs secreted from a panel of MM cell lines were isolated from conditioned media by ultracentrifugation and fluorescently stained EVs were co-cultured with THP-1 monocyte cells. MM EVs from three cell lines displayed a differential yet dose-dependent uptake by THP-1 cells, with H929 EVs displaying the greatest EV uptake compared to MM.1s and U266 EVs suggesting that uptake efficiency is dependent on the cell line of origin. Furthermore, MM EVs increased the secretion of MMP-9 and IL-6 from monocytes, with H929 EVs inducing the greatest effect, consistent with the greatest uptake efficiency. Moreover, monocyte-conditioned media collected following H929 EV uptake significantly increased the migration and proliferation of MM cells. Finally, EV proteome analysis revealed differential cargo enrichment that correlates with disease progression including a significant enrichment of spliceosome-related proteins in H929 EVs compared to the U266 and MM.1s EVs. Overall, this study demonstrates that MM-derived EVs modulate monocyte function to promote tumour growth and metastasis and reveals possible molecular mechanisms involved.

NF-κB: Governing Macrophages in Cancer

Tumor-associated macrophages (TAMs) are the major component of the tumor microenvironment (TME), where they sustain tumor progression and or-tumor immunity. Due to their plasticity, macrophages can exhibit anti- or pro-tumor functions through the expression of different gene sets leading to distinct macrophage phenotypes: M1-like or pro-inflammatory and M2-like or anti-inflammatory. NF-κB transcription factors are central regulators of TAMs in cancers, where they often drive macrophage polarization toward an M2-like phenotype. Therefore, the NF-κB pathway is an attractive therapeutic target for cancer immunotherapy in a wide range of human tumors. Hence, targeting NF-κB pathway in the myeloid compartment is a potential clinical strategy to overcome microenvironment-induced immunosuppression and increase anti-tumor immunity. In this review, we discuss the role of NF-κB as a key driver of macrophage functions in tumors as well as the principal strategies to overcome tumor immunosuppression by targeting the NF-κB pathway.

Extracellular vesicles in hematological malignancies: EV-dence for reshaping the tumoral microenvironment

Following their discovery at the end of the 20th century, extracellular vesicles (EVs) ranging from 50-1,000 nm have proven to be paramount in the progression of many cancers, including hematological malignancies. EVs are a heterogeneous group of cell-derived membranous structures that include small EVs (commonly called exosomes) and large EVs (microparticles). They have been demonstrated to participate in multiple physiological and pathological processes by allowing exchange of biological material (including among others proteins, DNA and RNA) between cells. They are therefore a crucial way of intercellular communication. In this context, malignant cells can release these extracellular vesicles that can influence their microenvironment, induce the formation of a tumorigenic niche, and prepare and establish distant niches facilitating metastasis by significantly impacting the phenotypes of surrounding cells and turning them toward supportive roles. In addition, EVs are also able to manipulate the immune response and to establish an immunosuppressive microenvironment. This in turn allows for ideal conditions for heightened chemoresistance and increased disease burden. Here, we review the latest findings and reports studying the effects and therapeutic potential of extracellular vesicles in various hematological malignancies. The study of extracellular vesicles remains in its infancy; however, rapid advances in the analysis of these vesicles in the context of disease allow us to envision prospects to improve the detection and treatment of hematological malignancies.

d-lactate modulates M2 tumor-associated macrophages and remodels immunosuppressive tumor microenvironment for hepatocellular carcinoma

The polarization of tumor-associated macrophages (TAMs) from M2 to M1 phenotype demonstrates great potential for remodeling the immunosuppressive tumor microenvironment (TME) of hepatocellular carcinoma (HCC). d-lactate (DL; a gut microbiome metabolite) acts as an endogenous immunomodulatory agent that enhances Kupffer cells for clearance of pathogens. In this study, the potential of DL for transformation of M2 TAMs to M1 was confirmed, and the mechanisms underlying such polarization were mainly due to the modulation of phosphatidylinositol 3-kinase/protein kinase B pathway. A poly(lactide-co-glycolide) nanoparticle (NP) was used to load DL, and the DL-loaded NP was modified with HCC membrane and M2 macrophage-binding peptide (M2pep), forming a nanoformulation (DL@NP-M-M2pep). DL@NP-M-M2pep transformed M2 TAMs to M1 and remodeled the immunosuppressive TME in HCC mice, promoting the efficacy of anti-CD47 antibody for long-term animal survival. These findings reveal a potential TAM modulatory function of DL and provide a combinatorial strategy for HCC immunotherapy.

The response of CD59 NK cell and IL-6 level in Cynomolgus macaque immunized with inactivated SARS-CoV-2 vaccine candidate

Vaccination is deemed the best approach against the COVID-19 pandemic. In regard of safety and protectivity, the whole inactivated vaccine platform is advantageous and widely used. Whole inactivated vaccine provides broader protection against various antigenic components of SARS-CoV-2. This study aims to analyze the immune response of cynomolgus macaques (Macaca fascicularis) following inactivated SARS-CoV-2 vaccine administration. The analysis utilized the flow cytometry and enzyme-linked immunosorbent assay to evaluate CD59 NK cell expression and serum IL-6 level. This research used 6 macaques which were divided into 2 groups: Adult and Adolescence. Each group was consisted of 3 macaques. The macaques received two doses of 3 µg of inactivated SARS-CoV-2 vaccine with 21 days interval between first and second dose. CD59 and IL-6 level were measured before the first vaccination (D0), 21 days post-vaccination but before second dose (D21), and 14 days after the second dose (D35). The result showed significant escalation (p ≤ 0.05) of CD59 NK cell expression between D0, D21, and D35 in both adult and adolescence macaques. Higher expression of CD59 NK cell was found in adult macaques compared to adolescence macaques. Meanwhile, the level of IL-6 remained constant (p > 0.05) throughout D0, D21, and D35 in both groups. In conclusion, the inactivated SARS-CoV-2 vaccine candidate can increase CD59 NK cell expression significantly, while IL-6 level was mildly elevated although the differences were insignificant.

The role of tumor-derived extracellular vesicles containing noncoding RNAs in mediating immune cell function and its implications from bench to bedside

Extracellular vesicles (EVs) are membrane-encapsulated vesicles released by almost all cell types, which participate in intercellular communication by delivering different types of molecular cargoes, such as non-coding RNAs (ncRNAs). Accumulating evidence suggests that tumor-derived EVs act as a bridge for intercellular crosstalk between tumor cells and surrounding cells, including immune cells. Tumor-derived EVs containing ncRNAs (TEV-ncRNAs) mediate intercellular crosstalk to manipulate immune responses and affect the malignant phenotypes of cancer cells. In this review, we summarize the double-edged roles and the underlying mechanisms of TEV-ncRNAs in regulating innate and adaptive immune cells. We also highlight the advantages of using TEV-ncRNAs in liquid biopsies for cancer diagnosis and prognosis. Moreover, we outline the use of engineered EVs to deliver ncRNAs and other therapeutic agents for cancer therapy.

A Data-Mining Approach to Identify NF-kB-Responsive microRNAs in Tissues Involved in Inflammatory Processes: Potential Relevance in Age-Related Diseases

The nuclear factor NF-kB is the master transcription factor in the inflammatory process by modulating the expression of pro-inflammatory genes. However, an additional level of complexity is the ability to promote the transcriptional activation of post-transcriptional modulators of gene expression as non-coding RNA (i.e., miRNAs). While NF-kB’s role in inflammation-associated gene expression has been extensively investigated, the interplay between NF-kB and genes coding for miRNAs still deserves investigation. To identify miRNAs with potential NF-kB binding sites in their transcription start site, we predicted miRNA promoters by an in silico analysis using the PROmiRNA software, which allowed us to score the genomic region’s propensity to be miRNA cis-regulatory elements. A list of 722 human miRNAs was generated, of which 399 were expressed in at least one tissue involved in the inflammatory processes. The selection of “high-confidence” hairpins in miRbase identified 68 mature miRNAs, most of them previously identified as inflammamiRs. The identification of targeted pathways/diseases highlighted their involvement in the most common age-related diseases. Overall, our results reinforce the hypothesis that persistent activation of NF-kB could unbalance the transcription of specific inflammamiRNAs. The identification of such miRNAs could be of diagnostic/prognostic/therapeutic relevance for the most common inflammatory-related and age-related diseases.

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.

Distinct non-coding RNA cargo of extracellular vesicles from M1 and M2 human primary macrophages

Macrophages are important antigen presenting cells which can release extracellular vesicles (EVs) carrying functional cargo including non-coding RNAs. Macrophages can be broadly classified into M1 'classical' and M2 'alternatively-activated' macrophages. M1 macrophages have been linked with inflammation-associated pathologies, whereas a switch towards an M2 phenotype indicates resolution of inflammation and tissue regeneration. Here, we provide the first comprehensive analysis of the small RNA cargo of EVs from human M1 and M2 primary macrophages. Using small RNA sequencing, we identified several types of small non-coding RNAs in M1 and M2 macrophage EVs including miRNAs, isomiRs, tRNA fragments, piRNA, snRNA, snoRNA and Y-RNA fragments. Distinct differences were observed between M1 and M2 EVs, with higher relative abundance of miRNAs, and lower abundance of tRNA fragments in M1 compared to M2 EVs. MicroRNA-target enrichment analysis identified several gene targets involved in gene expression and inflammatory signalling pathways. EVs were also enriched in tRNA fragments, primarily originating from the 5' end or the internal region of the full length tRNAs, many of which were differentially abundant in M1 and M2 EVs. Similarly, several other small non-coding RNAs, namely snRNAs, snoRNAs and Y-RNA fragments, were differentially enriched in M1 and M2 EVs; we discuss their putative roles in macrophage EVs. In conclusion, we show that M1 and M2 macrophages release EVs with distinct RNA cargo, which has the potential to contribute to the unique effect of these cell subsets on their microenvironment.

Extracellular Vesicles in Multiple Myeloma-Cracking the Code to a Better Understanding of the Disease

Multiple myeloma (MM) is a plasma cell-derived malignancy that stands for around 1.5% of newly discovered cancer cases. Despite constantly improving treatment methods, the disease is incurable with over 13,000 deaths in the US and over 30,000 in Europe. Recent studies suggest that extracellular vesicles (EVs) might play a significant role in the pathogenesis and evolution of MM. Further investigation of their role could prove to be beneficial in establishing new therapies and hence, improve the prognosis of MM patients. What is more, EVs might serve as novel markers in diagnosing and monitoring the disease. Great advancements concerning the position of EVs in the pathophysiology of MM have recently been shown in research and in this review, we would like to delve into the still expanding state of knowledge.

Emerging roles of extracellular vesicles in normal and malignant hematopoiesis

Hematopoietic stem cells, regulated by their microenvironment (or “niche”), sustain the production of mature blood and immune cells. Leukemia cells remodel the microenvironment to enhance their survival, which is accompanied by the loss of support for normal hematopoiesis in hematologic malignancies. Extracellular vesicles (EVs) mediate intercellular communication in physiological and pathological conditions, and deciphering their functions in cell-cell interactions in the ecosystem can highlight potential therapeutic targets. In this Review, we illustrate the utility of EVs derived from various cell types, focusing on the biological molecules they contain and the behavioral alterations they can induce in recipient cells. We also discuss the potential for clinical application in hematologic malignancies, including EV-based therapeutic regimens, drug delivery via EVs, and the use of EVs (or their cargoes) as biomarkers.

A Journey through the Inter-Cellular Interactions in the Bone Marrow in Multiple Myeloma: Implications for the Next Generation of Treatments

Tumors are composed of a plethora of extracellular matrix, tumor and non-tumor cells that form a tumor microenvironment (TME) that nurtures the tumor cells and creates a favorable environment where tumor cells grow and proliferate. In multiple myeloma (MM), the TME is the bone marrow (BM). Non-tumor cells can belong either to the non-hematological compartment that secretes soluble mediators to create a favorable environment for MM cells to grow, or to the immune cell compartment that perform an anti-MM activity in healthy conditions. Indeed, marrow-infiltrating lymphocytes (MILs) are associated with a good prognosis in MM patients and have served as the basis for developing different immunotherapy strategies. However, MM cells and other cells in the BM can polarize their phenotype and activity, creating an immunosuppressive environment where immune cells do not perform their cytotoxic activity properly, promoting tumor progression. Understanding cell-cell interactions in the BM and their impact on MM proliferation and the performance of tumor surveillance will help in designing efficient anti-MM therapies. Here, we take a journey through the BM, describing the interactions of MM cells with cells of the non-hematological and hematological compartment to highlight their impact on MM progression and the development of novel MM treatments.

Phosphoinositide 3-kinase/Akt and its related signaling pathways in the regulation of tumor-associated macrophages polarization

Tumor-associated macrophages (TAMs) are a type of functionally plastic immune cell population in tumor microenvironment (TME) and mainly polarized into two phenotypes: M2 and M1-like TAMs. The M2-like TAMs could stimulate tumor growth and metastasis, tissue remodeling and immune-suppression, whereas M1-like TAMs could initiate immune response to dampen tumor progression. TAMs with different polarization phenotypes can produce various kinds of cytokines, chemokines and growth factors to regulate immunity and inflammatory responses. It is an effective method to treat cancer through ameliorating TME and modulating TAMs by converting M2 into M1-like phenotype. However, intracellular signaling mechanisms underlying TAMs polarization are largely undefined. Phosphoinositide 3-kinase (PI3K)/Akt is an important signaling pathway participating in M2-like TAMs polarization, survival, growth, proliferation, differentiation, apoptosis and cytoskeleton rearrangement. In the present review, we analyzed the mechanism of TAMs polarization focusing on PI3K/Akt and its downstream mitogen‑activated protein kinase (MAPK) as well as nuclear factor kappa B (NF-κB) signaling pathways, thus provides the first evidence of intracellular targets for cancer immunotherapy.

A positive feedback loop between gastric cancer cells and tumor-associated macrophage induces malignancy progression

BACKGROUND

Hypoxia and inflammation tumor microenvironment (TME) play a crucial role in tumor development and progression. Although increased understanding of TME contributed to gastric cancer (GC) progression and prognosis, the direct interaction between macrophage and GC cells was not fully understood.

METHODS

Hypoxia and normoxia macrophage microarrays of GEO database was analyzed. The peripheral blood mononuclear cell acquired from the healthy volunteers. The expression of C-X-C Motif Chemokine Ligand 8 (CXCL8) in GC tissues and cell lines was detected by quantitative reverse transcription PCR (qRT-PCR), western-blot, Elisa and immunofluorescence. Cell proliferation, migration, and invasion were evaluated by cell counting kit 8 (CCK8), colony formation, real-time imaging of cell migration and transwell. Flow Cytometers was applied to identify the source of cytokines. Luciferase reporter assays and chromatin immunoprecipitation were used to identify the interaction between transcription factor and target gene. Especially, a series of truncated and mutation reporter genes were applied to identify precise binding sites. The corresponding functions were verified in the complementation test and in vivo animal experiment.

RESULTS

Our results revealed that hypoxia triggered macrophage secreted CXCL8, which induced GC invasion and proliferation. This macrophage-induced GC progression was CXCL8 activated C-X-C Motif Chemokine Receptor 1/2 (CXCR1/2) on the GC cell membrane subsequently hyperactivated Janus kinase 1/ Signal transducer and activator of transcription 1 (JAK/STAT1) signaling pathway. Then, the transcription factor STAT1 directly led to the overexpression and secretion of Interleukin 10 (IL-10). Correspondingly, IL-10 induced the M2-type polarization of macrophages and continued to increase the expression and secretion of CXCL8. It suggested a positive feedback loop between macrophage and GC. In clinical GC samples, increased CXCL8 predicted a patient's pessimistic outcome.

CONCLUSION

Our work identified a positive feedback loop governing cancer cells and macrophage in GC that contributed to tumor progression and patient outcome.

The Role of T Cell Immunity in Monoclonal Gammopathy and Multiple Myeloma: From Immunopathogenesis to Novel Therapeutic Approaches

Multiple Myeloma (MM) is a malignant growth of clonal plasma cells, typically arising from asymptomatic precursor conditions, namely monoclonal gammopathy of undetermined significance (MGUS) and smoldering MM (SMM). Profound immunological dysfunctions and cytokine deregulation are known to characterize the evolution of the disease, allowing immune escape and proliferation of neoplastic plasma cells. In the past decades, several studies have shown that the immune system can recognize MGUS and MM clonal cells, suggesting that anti-myeloma T cell immunity could be harnessed for therapeutic purposes. In line with this notion, chimeric antigen receptor T cell (CAR-T) therapy is emerging as a novel treatment in MM, especially in the relapsed/refractory disease setting. In this review, we focus on the pivotal contribution of T cell impairment in the immunopathogenesis of plasma cell dyscrasias and, in particular, in the disease progression from MGUS to SMM and MM, highlighting the potentials of T cell-based immunotherapeutic approaches in these settings.

Exposure to a mixture of heavy metals induces cognitive impairment: Genes and microRNAs involved

Converging evidence demonstrates that microRNAs (miRNAs) play an important role in the etiology of cognitive impairment. Thus, we aim to: (i) identify the molecular mechanisms of heavy metals, particularly miRNAs involved in the development of cognitive impairment; and (ii) generate miRNA sponges to prevent them from binding with their target messenger RNAs. The Comparative Toxicogenomics Database (CTD; http://ctd.mdibl.org), MicroRNA ENrichment TURned NETwork (MIENTURNET, http://userver.bio.uniroma1.it/apps/mienturnet/) and the microRNA sponge generator and tester (miRNAsong, http://www.med.muni.cz/histology/miRNAsong) were used as the core data-mining approaches in the current study. We observed that lead acetate, arsenic, gold, copper, iron, and aluminum, as well as their mixtures, had significant effects on the development of cognitive impairment. Although prevalent genes obtained from investigated heavy metals of cognitive impairment were different, the "PI3K-Akt signaling pathway", "pathways of neurodegeneration-multiple diseases", "apoptosis", "apoptosis-multiple species", "p53 signaling pathway", "NF-kappa B signaling pathway", and "Alzheimer's disease pathway" were highlighted. The mixed heavy metals altered the genes BAX, CASP3, BCL2, TNF, and IL-1B, indicating the significance of apoptosis and pro-inflammatory cytokines in the pathogenesis of cognitive impairment and the possibility of targeting these genes in future neuroprotective therapy. In addition, we used a network-based approach to identify key genes, miRNAs, pathways, and diseases related to the development of cognitive impairment. We also found 16 significant miRNAs related to cognitive impairment (hsa-miR-1-3p, hsa-let-7a-5p, hsa-miR-9-5p, hsa-miR-16-5p, hsa-miR-17-5p, hsa-miR-20a-5p, hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-34a-5p, hsa-miR-101-3p, hsa-miR-106a-5p, hsa-miR-128-3p, hsa-miR-144-3p, hsa-miR-199a-3p, hsa-miR-204-5p, and hsa-miR-335-5p). Finally, we created and evaluated miRNA sponge sequences for these miRNAs in silico. Further studies, including in vivo and in vitro, are needed to assess the link between these genes, miRNAs, pathways, and cognitive impairment.

Extracellular vesicle proteomic analysis leads to the discovery of HDGF as a new factor in multiple myeloma biology

HDGF is secreted by and found in multiple myeloma cell extracellular vesicles; it activates AKT and sustains multiple myeloma cell growth.

HDGF polarizes naïve macrophages to an M1 phenotype and generates immunosuppressive M-MDSC.

Identifying factors secreted by multiple myeloma (MM) cells that may contribute to MM tumor biology and progression is of the utmost importance. In this study, hepatoma-derived growth factor (HDGF) was identified as a protein present in extracellular vesicles (EVs) released from human MM cell lines (HMCLs). Investigation of the role of HDGF in MM cell biology revealed lower proliferation of HMCLs following HDGF knockdown and AKT phosphorylation following the addition of exogenous HDGF. Metabolic analysis demonstrated that HDGF enhances the already high glycolytic levels of HMCLs and significantly lowers mitochondrial respiration, indicating that HDGF may play a role in myeloma cell survival and/or act in a paracrine manner on cells in the bone marrow (BM) tumor microenvironment (ME). Indeed, HDGF polarizes macrophages to an M1-like phenotype and phenotypically alters naïve CD14⁺ monocytes to resemble myeloid-derived suppressor cells which are functionally suppressive. In summary, HDGF is a novel factor in MM biology and may function to both maintain MM cell viability as well as modify the tumor ME.

Deciphering mechanisms of immune escape to inform immunotherapeutic strategies in multiple myeloma

Multiple myeloma is an incurable cancer characterized by the uncontrolled growth of malignant plasma cells nurtured within a permissive bone marrow microenvironment. While patients mount numerous adaptive immune responses directed against their disease, emerging data demonstrate that tumor intrinsic and extrinsic mechanisms allow myeloma cells to subvert host immunosurveillance and resist current therapeutic strategies. Myeloma downregulates antigens recognized by cellular immunity and modulates the bone marrow microenvironment to promote uncontrolled tumor proliferation, apoptotic resistance, and further hamper anti-tumor immunity. Additional resistance often develops after an initial clinical response to small molecules, immune-targeting antibodies, immune checkpoint blockade or cellular immunotherapy. Profound quantitative and qualitative dysfunction of numerous immune effector cell types that confer anti-myeloma immunity further supports myelomagenesis, disease progression and the emergence of drug resistance. Identification of tumor intrinsic and extrinsic resistance mechanisms may direct the design of rationally-designed drug combinations that prevent or overcome drug resistance to improve patient survival. Here, we summarize various mechanisms of immune escape as a means to inform novel strategies that may restore and improve host anti-myeloma immunity.

Exosome-Mediated Crosstalk Between Tumor and Tumor-Associated Macrophages

Exosomes are nanosized vesicles, derived from the endolysosomal compartment of cells and can shuttle diverse biomolecules such as nucleic acids, proteins, lipids, amino acids, and metabolites, which can reflect their origin cells. Delivery of these cargoes to recipient cells enables exosomes to influence diverse cellular functions. As one of the most abundant immune cells in the tumor microenvironment, tumor-associated macrophages (TAMs) are educated by the tumor milieu, which is rich in cancer cells and stroma components, to exert functions such as the promotion of tumor growth, immunosuppression, angiogenesis, and cancer cell dissemination. Herein, we focus on exosomes-mediated intercellular communication between tumor cells and TAM in the tumor microenvironment, which may provide new targets for anti-tumor treatment. In this review, we highlight the most recent studies on the effect of tumor/macrophage-derived exosomes on macrophage/tumor function in different cancer types.

microRNA-based diagnostic and therapeutic applications in cancer medicine

It has been almost two decades since the first link between microRNAs and cancer was established. In the ensuing years, this abundant class of short noncoding regulatory RNAs has been studied in virtually all cancer types. This tremendously large body of research has generated innovative technological advances for detection of microRNAs in tissue and bodily fluids, identified the diagnostic, prognostic, and/or predictive value of individual microRNAs or microRNA signatures as potential biomarkers for patient management, shed light on regulatory mechanisms of RNA-RNA interactions that modulate gene expression, uncovered cell-autonomous and cell-to-cell communication roles of specific microRNAs, and developed a battery of viral and nonviral delivery approaches for therapeutic intervention. Despite these intense and prolific research efforts in preclinical and clinical settings, there are a limited number of microRNA-based applications that have been incorporated into clinical practice. We review recent literature and ongoing clinical trials that highlight most promising approaches and standing challenges to translate these findings into viable microRNA-based clinical tools for cancer medicine. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Circulating microRNAs Correlate with Multiple Myeloma and Skeletal Osteolytic Lesions

Simple Summary

Molecular biomarkers for the diagnosis of multiple myeloma and for the early detection of the associated osteolytic lesions are needed. MicroRNAs are a class of small non-coding RNAs that regulate gene expression post-transcriptionally and have been explored as circulating (extracellular) biomarkers for distinct diseases. Results show that miR-16-5p, miR-20a-5p, and miR-21-5p levels are differently expressed in the plasma of multiple myeloma patients compared with the control group and suggest that their combined expression could be used as a potential circulating biomarker. Furthermore, the expression of plasma microRNAs significantly correlates with myeloma bone disease and with bone lesions in the spine.

Abstract

Multiple myeloma (MM) is the second most frequent hematological disease and can cause skeletal osteolytic lesions. This study aims to evaluate the expression of circulating microRNAs (miRNAs) in MM patients and to correlate those levels with clinicopathological features, including bone lesions. A panel of miRNAs associated with MM onset and progression, or with bone remodeling, was analyzed in the plasma of 82 subjects (47 MM patients; 35 healthy controls). Results show that miR-16-5p, miR-20a-5p, and miR-21-5p are differently expressed between MM patients and healthy controls. Receiver operating characteristic analyses indicate that their combined expression has potential as a molecular marker (Area Under the Curve, AUC of 0.8249). Furthermore, significant correlations were found between the analyzed miRNAs and disease stage, treatment, β2 microglobulin, serum albumin and creatinine levels, but not with calcium levels or genetic alterations. In this cohort, 65.96% of MM patients had bone lesions, the majority of which were in the vertebrae. Additionally, miR-29c-3p was decreased in patients with osteolytic lesions compared with patients without bone disease. Interestingly, circulating levels of miR-29b-3p correlated with cervical and thoracic vertebral lesions, while miR-195-5p correlated with thoracic lesions. Our findings suggest circulating miRNAs can be promising biomarkers for MM diagnosis and that their levels correlate with myeloma bone disease and osteolytic lesions.

LncRNA CAIF suppresses LPS-induced inflammation and apoptosis of cardiomyocytes through regulating miR-16 demethylation

BACKGROUND

The long noncoding RNA, cardiac autophagy inhibitory factor (CAIF), and microRNA (miR)-16 are reported to be involved in lipopolysaccharide (LPS)-induced inflammatory responses and cell apoptosis in many diseases. Herein, we investigated the interaction between CAIF and miR-16 in sepsis-induced chronic heart failure (CHF).

METHODS

The expression of CAIF and miR-16 in plasma samples from sepsis-induced CHF patients (n = 60) and healthy controls (n = 60) were measured using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The correlations between CAIF and miR-16 across plasma samples from patients with sepsis-induced CHF and healthy controls were analyzed using linear regression. The messenger RNA (mRNA) levels of inducible nitric oxide synthase, C-C motif chemokine 2 (CCL2), growth-regulated alpha protein (CXCL1), and interleukin-6 (IL-6) were evaluated using qRT-PCR while nuclear factor κB activation was evaluated using luciferase assay.

RESULTS

The expression levels of CAIF and miR-16 were downregulated in the plasma of sepsis-induced CHF patients and were positively correlated in these patients. In cardiomyocytes, LPS treatment dose-dependently decreased CAIF and miR-16 levels. CAIF overexpression increased miR-16 expression by demethylating miR-16. CAIF and/or miR-16 overexpression suppressed LPS-induced CCL2, CXCL1, and IL-6 expression at both the mRNA and protein levels. Analysis of cell apoptosis and western blot analysis showed that CAIF and/or miR-16 overexpression inhibited LPS-induced cardiomyocyte apoptosis by reducing Bax and cleaved caspase 3 levels and enhancing Bcl-2 levels.

CONCLUSION

Our study is the first to report the abnormal expression of CAIF and miR-16 in heart disease. CAIF plays a protective role in sepsis-induced CHF by inhibiting cardiomyocyte apoptosis and inflammation, possibly by regulating miR-16 demethylation.

The Emerging Role of Extracellular Vesicle-Associated RNAs in the Multiple Myeloma Microenvironment

Multiple myeloma (MM) is a cancer of terminally differentiated plasma cells (PCs) that develop at multiple sites within the bone marrow (BM). MM is treatable but rarely curable because of the frequent emergence of drug resistance and relapse. Increasing evidence indicates that the BM microenvironment plays a major role in supporting MM-PC survival and resistance to therapy. The BM microenvironment is a complex milieu containing hematopoietic cells, stromal cells, endothelial cells, immune cells, osteoclasts and osteoblasts, all contributing to the pathobiology of MM, including PC proliferation, escape from immune surveillance, angiogenesis and bone disease development. Small extracellular vesicles (EVs) are heterogenous lipid structures released by all cell types and mediate local and distal cellular communication. In MM, EVs are key mediators of the cross-talk between PCs and the surrounding microenvironment because of their ability to deliver bioactive cargo molecules such as lipids, mRNAs, non-coding regulatory RNA and proteins. Hence, MM-EVs highly contribute to establish a tumor-supportive BM niche that impacts MM pathogenesis and disease progression. In this review, we will first highlight the effects of RNA-containing, MM-derived EVs on the several cellular compartments within the BM microenvironment that play a role in the different aspects of MM pathology. We will also touch on the prospective use of MM-EV-associated non-coding RNAs as clinical biomarkers in the context of “liquid biopsy” in light of their importance as a promising tool in MM diagnosis, prognosis and prediction of drug resistance.

Anti‑inflammatory role of microRNA‑429 in human gingival epithelial cells‑inhibition of IL‑8 production through direct binding to IKKβ mRNA

MicroRNAs (miRNAs), a family of small non‑coding RNAs, serve a pivotal role in the regulation of the inflammation by modulating the expression of various genes. However, the molecular mechanism by which miRNAs regulate inflammation‑associated molecules in oral epithelial cells remains to be elucidated. The present study examined the biological function of miR‑429 by performing the gain‑/loss‑of‑function studies of miR‑429 in a gingival squamous cell carcinoma line Ca9‑22 cells that either over‑ or under‑expressed miR‑429 through transient transfection with miR‑429 mimic or miR‑429 inhibitor, respectively. The results demonstrated that the over‑expression of miR‑429 suppressed the mRNA level of several interleukins, including IL‑8. In addition, the over‑expression of miR‑429 reduced IL‑8 secretion under the basal and TNF‑α stimulated conditions, whereas the secretion of IL‑8 was enhanced when miR‑429 was under‑expressed. The over‑expression of miR‑429 inhibited the activation of the transcription factor NF‑κB. Furthermore, we found that miR‑429 suppressed both mRNA and protein levels of IKKβ via its direct binding to the 3'‑untranslated region of IKKβ mRNA. In addition, the downregulation of IKKβ by small interfering RNA reduced both NF‑kB activity and IL‑8 production in Ca9‑22 cells. Taken together, the findings revealed the molecular mechanism of miR‑429 to regulate the inflammatory mediator in gingival cells and suggested that it could be useful as a therapeutic target of oral inflammatory diseases.

Regulation of Nuclear Factor-KappaB (NF-κB) signaling pathway by non-coding RNAs in cancer: Inhibiting or promoting carcinogenesis?

The nuclear factor-kappaB (NF-κB) signaling pathway is considered as a potential therapeutic target in cancer therapy. It has been well established that transcription factor NF-κB is involved in regulating physiological and pathological events including inflammation, immune response and differentiation. Increasing evidences suggest that deregulated NF-κB signaling can enhance cancer cell proliferation, metastasis and also mediate radio-as well as chemo-resistance. On the contrary, non-coding RNAs (ncRNAs) have been found to modulate NF-κB signaling pathway under different settings. MicroRNAs (miRNAs) can dually inhibit/induce NF-κB signaling thereby affecting the growth and migration of cancer cells. Furthermore, the response of cancer cells to radiotherapy and chemotherapy may also be regulated by miRNAs. Regulation of NF-κB by miRNAs may be mediated via binding to 3^/-UTR region. Interestingly, anti-tumor compounds can increase the expression of tumor-suppressor miRNAs in inhibiting NF-κB activation and the progression of cancers. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can also effectively modulate NF-κB signaling thus affecting tumorigenesis. It is noteworthy that several studies have demonstrated that lncRNAs and circRNAs can affect miRNAs in targeting NF-κB activation. They can act as competing endogenous RNA (ceRNA) thereby reducing miRNA expression to induce NF-κB activation that can in turn promote cancer progression and malignancy.

Elevation of miR-302b prevents multiple myeloma cell growth and bone destruction by blocking DKK1 secretion

BACKGROUND

Myeloma bone disease (MBD) is a severe complication of multiple myeloma (MM) mainly due to an imbalance between enhanced osteoclast activity and reduced osteoblast function. Previous studies have demonstrated that miRNAs play a vital role in the osteogenic differentiation of mesenchymal stromal cells (MSCs) in MM. However, the value of miR‑302b in MBD remains to be further elucidated. The aim of this study is to explore the role of miR‑302b in the regulation of MBD osteogenic differentiation and evaluate the potential of a new therapeutic strategy for the clinical treatment of MBD.

METHOD

Our previous research demonstrated that MiR-302b belongs to the miR-302 cluster and is able to inhibit tumor growth and osteolysis in an orthotopic osteosarcoma xenograft tumor mouse model. In this study, we first transfected miR-302b mimics, miR-302b inhibitor, and miR-302b NC into MM1.S and RPMI8226 MM cells to detect the correlation between miR-302b expression in the pathological specimens and the clinicopathological features by qPCR, the target correlation between miR-302b and DKK1 by immunohistochemistry, qPCR and Western blot, and the correlation between miR-302b and the Wnt/β-catenin signaling pathway by Western blot. The effect of miR-302b on osteoblastogenesis was also studied in a subperiosteal tumorigenesis model of NOD/SCID nude mice.

RESULTS

We found that increased miR-302b suppressed cell proliferation and induced cell apoptosis in RPMI 8226 and MM1.S cells. TargetScan online bioinformatic analysis predicted that miR-302b is able to bind to 3'UTR of DKK1 mRNA. Target binding of miR-302b to DKK1 was demonstrated by dual-luciferase reporter assay, qPCR, Western blot and immunohistochemistry, indicating that miR-302b is able to degrade DKK1 in RPMI 8226 and MM1.S cells. The model of co-culturing MM cells with preosteoblast MC3T3-E1 cells showed that miR-302b inhibits MM-induced suppression of osteoblast differentiation. Western blotting showed that miR-302b promotes the Wnt/β-catenin signaling pathway in MM cells. Micro-CT and immunohistochemistry results showed that miR-302b suppresses myeloma bone destruction in vivo.

CONCLUSION

miR-302b is able to target DKK1 and promote the Wnt/β-catenin signaling pathway in MM.

BATF2 prevents glioblastoma multiforme progression by inhibiting recruitment of myeloid-derived suppressor cells

The basic leucine zipper ATF-like transcription factor 2 (BATF2) has been implicated in inflammatory responses and anti-tumour effects. Little, however, is known regarding its extracellular role in maintaining a non-supportive cancer microenvironment. Here, we show that BATF2 inhibits glioma growth and myeloid-derived suppressor cells (MDSCs) recruitment. Interestingly, extracellular vesicles (EVs) from BATF2-overexpressing glioma cell lines (BATF2-EVs) inhibited MDSCs chemotaxis in vitro. Moreover, BATF2 inhibited intracellular SDF-1α and contributes to decreased SDF-1α in EVs. In addition, BATF2 downregulation-induced MDSCs recruitment were reversed by blocking SDF-1α/CXCR4 signalling upon AMD3100 treatment. Specifically, detection of EVs in 24 pairs of gliomas and healthy donors at different stages revealed that the abundance of BATF2-positive EVs in plasma (BATF2⁺ plEVs) can distinguish stage III-IV glioma from stage I-II glioma and healthy donors. Taken together, our study identified novel regulatory functions of BATF2 in regulating MDSCs recruitment, providing a prognostic value in terms of the number of BATF2⁺ plEVs in glioma stage.

Extracellular Vesicles in Hematological Malignancies: From Biomarkers to Therapeutic Tools

Small extracellular vesicles (EVs) are a heterogenous group of lipid particles released by all cell types in physiological and pathological states. In hematological malignancies, tumor-derived EVs are critical players in mediating intercellular communications through the transfer of genetic materials and proteins between neoplastic cells themselves and to several components of the bone marrow microenvironment, rendering the latter a “stronger” niche supporting cancer cell proliferation, drug resistance, and escape from immune surveillance. In this context, the molecular cargoes of tumor-derived EVs reflect the nature and status of the cells of origin, making them specific therapeutic targets. Another important characteristic of EVs in hematological malignancies is their use as a potential “liquid biopsy” because of their high abundance in biofluids and their ability to protect their molecular cargoes from nuclease and protease degradation. Liquid biopsies are non-invasive blood tests that provide a molecular profiling clinical tool as an alternative method of disease stratification, especially in cancer patients where solid biopsies have limited accessibility. They offer accurate diagnoses and identify specific biomarkers for monitoring of disease progression and response to treatment. In this review, we will focus on the role of EVs in the most prevalent hematological malignancies, particularly on their prospective use as biomarkers in the context of liquid biopsies, as well as their molecular signature that identifies them as specific therapeutic targets for inhibiting cancer progression. We will also highlight their roles in modulating the immune response by acting as both immunosuppressors and activators of anti-tumor immunity.

Protein Kinase D 1 Predicts Poor Treatment Response and Unfavorable Survival of Bortezomib-Based Treatment, and Its Knockdown Enhances Drug Sensitivity to Bortezomib in Multiple Myeloma

Objective:

The present study aimed to explore the correlation of protein kinase D 1 with prognosis in bortezomib-treated multiple myeloma patients and further investigate the effect of protein kinase D 1 knockdown on drug sensitivity to bortezomib in multiple myeloma cells.

Methods:

Totally, 104 de novo symptomatic multiple myeloma patients treated with bortezomib-based regimens and 30 healthy controls were recruited. Bone marrow mononuclear cells–derived plasma cells were collected from multiple myeloma patients before initial treatment and from healthy controls on the bone marrow donation, respectively, then protein kinase D 1 protein/messenger RNA expressions were detected by Western blot and reverse transcription quantitative polymerase chain reaction, respectively. The effect of protein kinase D 1 knockdown on drug sensitivity to bortezomib was detected by transfecting protein kinase D 1 knockdown plasmid and control plasmid into RPMI8226 and U266 cells.

Results:

Protein kinase D 1 protein/messenger RNA expressions were both upregulated in multiple myeloma patients compared with healthy controls and presented good value in differentiating multiple myeloma patients from healthy controls. Furthermore, protein kinase D 1 protein/messenger RNA expressions were both associated with high International Staging System stage and t (4; 14). Furthermore, both complete response rate and overall response rate were reduced in protein kinase D 1 high patients compared with protein kinase D 1 low patients; similarly, progression-free survival and overall survival were both decreased in protein kinase D 1 high patients compared with protein kinase D 1 low patients. In addition, in RPMI8226 and U266 multiple myeloma cells, protein kinase D 1 knockdown increased drug sensitivity to bortezomib.

Conclusion:

Protein kinase D 1 has the potential to predict poor treatment response and unfavorable survival of bortezomib-based treatment in multiple myeloma patients, and its knockdown enhanced drug sensitivity to bortezomib in multiple myeloma cells.

A Comprehensive Biological and Clinical Perspective Can Drive a Patient-Tailored Approach to Multiple Myeloma: Bridging the Gaps between the Plasma Cell and the Neoplastic Niche

There is a broad spectrum of diseases labeled as multiple myeloma (MM). This is due not only to the composite prognostic risk factors leading to different clinical outcomes and responses to treatments but also to the composite tumor microenvironment that is involved in a vicious cycle with the MM plasma cells. New therapeutic strategies have improved MM patients' chances of survival. Nevertheless, certain patients' subgroups have a particularly unfavorable prognosis. Biological stratification can be subdivided into patient, disease, or therapy-related factors. Alternatively, the biological signature of aggressive disease and dismal therapeutic response can promote a dynamic, comprehensive strategic approach, better tailoring the clinical management of high-risk profiles and refractoriness to therapy and taking into account the role played by the MM milieu. By means of an extensive literature search, we have reviewed the state-of-the-art pathophysiological insights obtained from translational investigations of the MM-bone marrow microenvironment. A good knowledge of the MM niche pathophysiological dissection is crucial to tailor personalized approaches in a bench-bedside fashion. The discussion in this review pinpoints two main aspects that appear fundamental in order to gain novel and definitive results from the biology of MM. A systematic knowledge of the plasma cell disorder, along with greater efforts to face the unmet needs present in MM evolution, promises to open a new therapeutic window looking out onto the plethora of scientific evidence about the myeloma and the bystander cells.

Monosomic loss of MIR15A/MIR16-1 is a driver of multiple myeloma proliferation and disease progression

The most common genetic abnormality in multiple myeloma (MM) is the deletion of chromosome 13, seen in almost half of newly diagnosed patients. Unlike chronic lymphocytic leukemia, where a recurrent minimally deleted region including MIR15A/MIR16-1 has been mapped, the deletions in MM predominantly involve the entire chromosome and no specific driver gene has been identified. Additional candidate loci include RB1 and DIS3, but while biallelic deletion of RB1 is associated with disease progression, DIS3 is a common essential gene and complete inactivation is not observed. The Vk*MYC transgenic mouse model of MM spontaneously acquires del(14), syntenic to human chromosome 13, and Rb1 complete inactivation, but not Dis3 mutations. Taking advantage of this model, we explored the role in MM initiation and progression of two candidate loci on chromosome 13: RB1 and MIR15A/MIR16-1. Monoallelic deletion of Mir15a/Mir16-1 but not Rb1 was sufficient to accelerate the development of monoclonal gammopathy in wildtype mice, and the progression of MM in Vk*MYC mice, resulting in increased expression of Mir15a/Mir16-1 target genes and plasma cell proliferation, which was similarly observed in patients with MM.