miRNA-202 in bone marrow stromal cells affects the growth and adhesion of multiple myeloma cells by regulating B cell-activating factor

Dysregulation of Non-Coding RNAs: Roles of miRNAs and lncRNAs in the Pathogenesis of Multiple Myeloma

The dysregulation of non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), leads to the development and advancement of multiple myeloma (MM). miRNAs, in particular, are paramount in post-transcriptional gene regulation, promoting mRNA degradation and translational inhibition. As a result, miRNAs can serve as oncogenes or tumor suppressors depending on the target genes. In MM, miRNA disruption could result in abnormal gene expression responsible for cell growth, apoptosis, and other biological processes pertinent to cancer development. The dysregulated miRNAs inhibit the activity of tumor suppressor genes, contributing to disease progression. Nonetheless, several miRNAs are downregulated in MM and have been identified as gene regulators implicated in extracellular matrix remodeling and cell adhesion. miRNA depletion potentially facilitates the tumor advancement and resistance of therapeutic drugs. Additionally, lncRNAs are key regulators of numerous cellular processes, such as gene expression, chromatin remodeling, protein trafficking, and recently linked MM development. The lncRNAs are uniquely expressed and influence gene expression that supports MM growth, in addition to facilitating cellular proliferation and viability via multiple molecular pathways. miRNA and lncRNA alterations potentially result in anomalous gene expression and interfere with the regular functioning of MM. Thus, this review aims to highlight the dysregulation of these ncRNAs, which engender novel therapeutic modalities for the treatment of MM.

MicroRNA-202-5p-dependent inhibition of Bcl-2 contributes to macrophage apoptosis and atherosclerotic plaque formation

BACKGROUND

The identification of microRNA (miRNA)-related molecular mechanisms has advanced the development of new therapeutics for atherosclerosis (AS). The roles of miR-202-5p- in the pathogenic mechanisms of AS have not been explored.

METHODS

Macrophages were transfected with a series of miR-202-5p mimic/inhibitor, and then assessed for changes in viability, apoptosis, and secretion of inflammatory cytokines. The regulatory mechanism of miR-202-5p was explored through dual-luciferase reporter gene assay. A mouse model of AS was developed in ApoE^-/- mice fed with high-fat diet to examine the in vivo effects of miR-202-5p on atherosclerotic plaque formation, collagen synthesis, and fiber cap thickness.

RESULTS

Elevated miR-202-5p was found in atherosclerotic plaque tissues of the mice. miR-202-5p was able to induce macrophage apoptosis and release of pro-inflammatory factors. Besides, miR-202-5p limited Bcl-2 expression and elevated the levels of Bax, cleaved caspase-3, and cleaved caspase-9. Bcl-2 was concluded as a target gene of miR-202-5p. The pro-apoptotic effect of miR-202-5p on macrophages was achieved via limiting Bcl-2. In the mouse AS model, restoration of miR-202-5p stimulated atherosclerotic plaque formation, but reduced collagen synthesis and fiber cap thickness.

CONCLUSION

These data collectively suggest a pro-apoptotic action of miR-202-5p in macrophages that contributes to atherosclerotic plaque formation.

Noncoding RNAs in the crosstalk between multiple myeloma cells and bone marrow microenvironment

Multiple myeloma (MM) is the second most common hematological malignancy; however, it remains incurable, and the underlying pathogenesis and mechanisms of drug resistance remain unclear. It is widely recognized that the bone marrow microenvironment plays a crucial role in regulating the immune response, inducing drug resistance, and promoting tumor proliferation and invasion in MM, and thus serves as a potential therapeutic target. Among the various signaling loops between myeloma cells and components of the microenvironment, noncoding RNAs are emerging as crucial regulators of intercellular communication within the microenvironment. Noncoding RNAs, such as microRNAs, long noncoding RNAs, circular RNAs, and PIWI-interacting RNAs, have been associated with numerous biological processes involved in myeloma cell growth, survival, migration, invasion, and drug resistance. This review summarizes recent advances in the regulatory mechanisms of noncoding RNAs involved in the interaction between the MM bone marrow microenvironment and discusses the therapeutic potential of noncoding RNAs in MM.

miRNAs and Multiple Myeloma: Focus on the Pathogenesis, Prognosis, and Drug Resistance

Multiple myeloma (MM) produces clonal plasma cells and aberrant monoclonal antibody accumulation in patients' bone marrow (BM). Around 1% of all cancers and 13% of hematological malignancies are caused by MM, making it one of the most common types of cancer. Diagnostic and therapeutic methods for managing MM are currently undergoing extensive research. MicroRNAs (miRNAs) are short noncoding RNAs that reduce or inhibit the translation of their target mRNA after transcription. Because miRNAs play an influential role in how myeloma develops, resources, and becomes resistant to drugs, miRNA signatures may be used to diagnose, do prognosis, and treat the myeloma response. Consequently, researchers have investigated the levels of miRNA in plasma cells from MM patients and developed tools to test whether they directly impacted tumor growth. This review discusses the latest discoveries in miRNA science and their role in the development of MM. We also emphasize the potential applications of miRNAs to diagnose, prognosticate, and treat MM in the future.

Role of Platelet-Rich Plasma Gel in Promoting Wound Healing Based on Medical Images of Wounds

A wound is the pathological change of soft tissue under normal skin caused by various factors, such as collision, contusion, hot crush, avulsion, corrosive chemicals, operations, excessive wound tension after operations, local pressure that cannot be relieved for a long time, liquid immersion, local infection, and rejection reactions caused by allogeneic substances. The skin itself or its underlying soft tissue loses its integrity and continuity, thus losing its normal physiological function. Medical image analysis is a medical term that refers to the interdisciplinary fields of integrated medical imaging, artificial intelligence, digital image processing and analysis, mathematical modeling, and numerical algorithms. According to the time of wound formation, they can be divided into acute and chronic wounds. The common acute wounds include lacerations caused by trauma, surgical incisions, burns, and donor sites formed after skin graft operations. This article mainly studies the role of platelet-rich plasma gel nanocomposites in promoting wound healing. It is proven that ptt-rich plasma gel can significantly promote tissue repair and regeneration and accelerate wound healing in patients with severe burns. The atomic number of the nanocomposite has a better treatment effect on the nanoparticle approach. In this paper, chitosan nanocomposite membrane, nanocomposite algorithm, and the calculation method of enthalpy of formation of high alloy nanomaterials were used to study the role of ptt-rich plasma gel combined chitosan nanocomposite membrane loaded bone marrow stromal cells in promoting wound healing, and its effects were applied to the repair of special site burns, special burns, and different age burns. Good wound repair benefits from the correct treatment of the wound, which directly affects the stability and development of the internal environment. The difference in healing time between the two groups was statistically significant, and the recovery time of the PRP group was 0.001 less than that of the control group. The results showed that the wound healing time of the PRP group was significantly shorter than that of the control group (P < 0.05); after treatment, the content of VEGF in the wound tissue of the two groups increased, especially in the PRP group; the effective rate of the PRP group was 75.0%, which was higher than 68.8% of the control group. It can play an important role in the regulation of expression and the pathophysiological process of wound healing.

The microRNA-202 as a Diagnostic Biomarker and a Potential Tumor Suppressor

MicroRNA-202 (miR-202) is a member of the highly conserved let-7 family that was discovered in Caenorhabditis elegans and recently reported to be involved in cell differentiation and tumor biology. In humans, miR-202 was initially identified in the testis where it was suggested to play a role in spermatogenesis. Subsequent research showed that miR-202 is one of the micro-RNAs that are dysregulated in different types of cancer. During the last decade, a large number of investigations has fortified a role for miR-202 in cancer. However, its functions can be double-edged, depending on context they may be tumor suppressive or oncogenic. In this review, we highlight miR-202 as a potential diagnostic biomarker and as a suppressor of tumorigenesis and metastasis in several types of tumors. We link miR-202 expression levels in tumor types to its involved upstream and downstream signaling molecules and highlight its potential roles in carcinogenesis. Three well-known upstream long non-coding-RNAs (lncRNAs); MALAT1, NORAD, and NEAT1 target miR-202 and inhibit its tumor suppressive function thus fueling cancer progression. Studies on the downstream targets of miR-202 revealed PTEN, AKT, and various oncogenes such as metadherin (MTDH), MYCN, Forkhead box protein R2 (FOXR2) and Kirsten rat sarcoma virus (KRAS). Interestingly, an upregulated level of miR-202 was shown by most of the studies that estimated its expression level in blood or serum of cancer patients, especially in breast cancer. Reduced expression levels of miR-202 in tumor tissues were found to be associated with progression of different types of cancer. It seems likely that miR-202 is embedded in a complex regulatory network related to the nature and the sensitivity of the tumor type and therapeutic (pre)treatments. Its variable roles in tumorigenesis are mediated in part thought its oncogene effectors. However, the currently available data suggest that the involved signaling pathways determine the anti- or pro-tumorigenic outcomes of miR-202’s dysregulation and its value as a diagnostic biomarker.

The exploration of quantum dot-molecular beacon based MoS2 fluorescence probing for myeloma-related Mirnas detection

Highly sensitive and reliable detection of multiple myeloma remains a major challenge in liquid biopsy. Herein, for the first time, quantum dot-molecular beacon (QD-MB) functionalized MoS₂ (QD-MB @MoS₂) fluorescent probes were designed for the dual detection of multiple myeloma (MM)-related miRNA-155 and miRNA-150. The results indicate that the two probes can effectively detect miRNA-155 and miRNA-150 simultaneously with satisfactory recovery rates, and the limit of detections (LODs) of miRNA-155 and miRNA-150 in human serum are low to 7.19 fM and 5.84 fM, respectively. These results indicate that our method is the most sensitive detection so far reported and that the designed fluorescent probes with signal amplification strategies can achieve highly sensitive detection of MM-related miRNAs for MM diagnosis.

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Novel quantum dot-molecular beacon functionalized MoS₂ (QD-MB@MoS₂) fluorescent probes were designed and fabricated.

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The dual detection of miRNA-155 and miRNA-150 with high sensitivity, low detection limit and high recovery was realized.

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The fluorescence probes have a great influence on the fluorescence quenching efficiency and the sensitivity.

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The new MB@MoS₂ fluorescent probe and dual detection strategy provide a valuable tool for the detection of miRNA.

Roles of miRNA dysregulation in the pathogenesis of multiple myeloma

Multiple myeloma (MM) is a malignant disease of plasma cells with complex pathology, causing significant morbidity due to its end-organ destruction. The outcomes of patients with myeloma have significantly improved in the past couple of decades with the introduction of novel agents, such as proteasome inhibitors, immunomodulators, and monoclonal antibodies. However, MM remains incurable and presents considerable individual heterogeneity. MicroRNAs (miRNAs) are short, endogenous noncoding RNAs of 19-22 nucleotides that regulate gene expression at the posttranscriptional level. Numerous studies have shown that miRNA deregulation is closely related to MM pathology, including tumor initiation, progression, metastasis, prognosis, and drug response, which make the complicated miRNA network an attractive and marvelous area of investigation for novel anti-MM therapeutic approaches. Herein, we mainly summarized the current knowledge on the roles of miRNAs, which are of great significance in regulating pathological factors involved in MM progressions, such as bone marrow microenvironment, methylation, immune regulation, genomic instability, and drug resistance. Meanwhile, their potential as novel prognostic biomarkers and therapeutic targets was also discussed.

Circulating miRNAs as Auxiliary Diagnostic Biomarkers for Multiple Myeloma: A Systematic Review, Meta-Analysis, and Recommendations

Multiple myeloma (MM) is a hematologic malignancy characterized by aberrant expansion of monoclonal plasma cells with high mortality and severe complications due to the lack of early diagnosis and timely treatment. Circulating miRNAs have shown potential in the diagnosis of MM with inconsistent results, which remains to be fully assessed. Here we updated a meta-analysis with relative studies and essays published in English before Jan 31, 2021. After steps of screening, 32 studies from 11 articles that included a total of 627 MM patients and 314 healthy controls were collected. All data were analyzed by REVMAN 5.3 and Stata MP 16, and the quality of included literatures was estimated by Diagnostic Accuracy Study 2 (QUADAS-2). The pooled area under the curve (AUC) shown in summary receiver operating characteristic (SROC) analyses of circulating miRNAs was 0.87 (95%CI, 0.81–0.89), and the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were 0.79, 0.86, 5, 0.27, 22, respectively. Meta-regression and subgroup analysis exhibited that “miRNA cluster”, patient “detailed stage or Ig isotype” accounted for a considerable proportion of heterogeneity, revealing the importance of study design and patient inclusion in diagnostic trials; thus standardized recommendations were proposed for further studies. In addition, the performance of the circulating miRNAs included in MM prognosis and treatment response prediction was summarized, indicating that they could serve as valuable biomarkers, which would expand their clinical application greatly.

IDO2 rs10109853 polymorphism affects the susceptibility to multiple myeloma

Single-nucleotide polymorphisms (SNPs) of the IDO1 and IDO2 genes have been associated with some diseases. Here, we investigated the association of IDO1 and IDO2 SNPs with the susceptibility to multiple myeloma (MM) and their relationships with MM clinical features. We obtained genomic DNA from 100 patients with MM and 149 healthy race-matched controls and determined IDO1 promoter - 1849G/T (rs3824259) and IDO2 R248W (rs10109853) genotypes by using the polymerase chain reaction-restriction fragment length polymorphism method. The patients with MM had a significantly higher frequency of the IDO2 R248W RR genotype (high-activity type) (59.0% vs. 43.6%, odds ratio = 1.86, 95% confidence interval = 1.11-3.11, P = 0.017) compared with those in healthy controls. Patients with the IDO2 R248W RR genotype (high-activity type) were significantly younger and had a significantly lower frequency of International Staging System (ISS) stage III condition than those with the RW and WW genotypes (median 63 years vs. 69 years, P = 0.025; 15 [25.4%] vs. 50 [48.8%]). In addition, the IDO2 R248W RR genotype was significantly associated with a higher level of hemoglobin at diagnosis (mean ± standard deviation, 10.7 ± 2.36 vs. 9.27 ± 2.40 g/dL; P = 0.0032). Neither polymorphism significantly affected overall survival. Our study indicates that IDO2 R248W may be associated with the susceptibility to MM and severity of anemia.

Potential Role of microRNAs in inducing Drug Resistance in Patients with Multiple Myeloma

The prognosis for newly diagnosed subjects with multiple myeloma (MM) has significantly progressed in recent years. However, most MM patients relapse and after several salvage therapies, the onset of multidrug resistance provokes the occurrence of a refractory disease. A continuous and bidirectional exchange of information takes place between the cells of the microenvironment and neoplastic cells to solicit the demands of cancer cells. Among the molecules serving as messengers, there are microRNAs (miRNA), a family of small noncoding RNAs that regulate gene expression. Numerous miRNAs are associated with drug resistance, also in MM, and the modulation of their expression or activity might be explored to reverse it. In this review we report the most recent studies concerning the relationship between miRNAs and chemoresistance to the most frequently used drugs, such as proteasome inhibitors, steroids, alkylating agents and immunomodulators. The experimental use of antagomirs or miRNA mimics have successfully been proven to counteract chemoresistance and display synergistic effects with antimyeloma drugs which could represent a fundamental moment to overcome resistance in MM treatment.

Bone marrow stromal cells derived exosomal miR-10a and miR-16 may be involved in progression of patients with multiple myeloma by regulating EPHA8 or IGF1R/CCND1

Interaction with bone marrow stromal cells (BMSCs) has been suggested as an important mechanism for the progression of multiple myeloma (MM) cells, while exosomes are crucial mediators for cell-to-cell communication. The study was to investigate the miRNA profile changes in exosomes released by BMSCs of MM patients and explore their possible function roles.The microarray datasets of exosomal miRNAs in BMSCs were downloaded from the Gene Expression Omnibus database (GSE110271: 6 MM patients, 2 healthy donors; GSE78865: 4 donors and 2 MM patients; GSE39571: 7 MM patients and 4 controls). The differentially expressed miRNAs (DEMs) were identified using the LIMMA method. The target genes of DEMs were predicted by the miRwalk 2.0 database and the hub genes were screened by constructing the protein-protein interaction (PPI) network, module analysis and overlapping with the differentially expressed genes (DEGs) after overexpression or knockout of miRNAs.Three downregulated DEMs were found to distinguish MM from normal and MM-MGUS controls in the GSE39571 dataset; one downregulated and one upregulated DEMs (hsa-miR-10a) could differentiate MM from normal and MM-MGUS controls in the GSE110271-GSE78865 merged dataset. Furthermore, 11 downregulated (hsa-miR-16) and 1 upregulated DEMs were shared between GSE39571 and merged dataset when comparing MM with normal samples. The target genes were predicted for these 17 DEMs. PPI with module analysis showed IGF1R and CCND1 were hub genes and regulated by hsa-miR-16. Furthermore, EPHA8 was identified as a DEG that was downregulated in MM cells when the use of has-miR-10a mimics; while IGF1R, CCND1, CUL3, and ELAVL1 were also screened as DEGs that were upregulated in MM cells when silencing of hsa-miR-16.BMSCs-derived exosomal miR-10a and miR-16 may be involved in MM progression by regulating EPHA8 or IGF1R/CCND1/CUL3/ELAVL1, respectively. These exosomal miRNAs or genes may represent potential biomarkers for diagnosis of MM and prediction of progression and targets for developing therapeutic drugs.

Pathogenic Mechanisms of Myeloma Bone Disease and Possible Roles for NRF2

Osteolytic bone lesions are one of the central features of multiple myeloma (MM) and lead to bone pain, fractures, decreased quality of life, and decreased survival. Dysfunction of the osteoclast (OC)/osteoblast (OB) axis plays a key role in the development of myeloma-associated osteolytic lesions. Many signaling pathways and factors are associated with myeloma bone diseases (MBDs), including the RANKL/OPG and NF-κB pathways. NRF2, a master regulator of inflammatory signaling, might play a role in the regulation of bone metabolism via anti-inflammatory signaling and decreased reactive oxygen species (ROS) levels. The loss of NRF2 expression in OCs reduced bone mass via the RANK/RANKL pathway and other downstream signaling pathways that affect osteoclastogenesis. The NRF2 level in OBs could interfere with interleukin (IL)-6 expression, which is associated with bone metabolism and myeloma cells. In addition to direct impact on OCs and OBs, the activity of NRF2 on myeloma cells and mesenchymal stromal cells influences the inflammatory stress/ROS level in these cells, which has an impact on OCs, OBs, and osteocytes. The interaction between these cells and OCs affects the osteoclastogenesis of myeloma bone lesions associated with NRF2. Therefore, we have reviewed the effects of NRF2 on OCs and OBs in MBDs.

Therapeutic targets in myeloma bone disease

Multiple myeloma (MM) is the second most common haematological malignancy and is characterized by a clonal proliferation of neoplastic plasma cells within the bone marrow. MM is the most frequent cancer involving the skeleton, causing osteolytic lesions, bone pain and pathological fractures that dramatically decrease MM patients' quality of life and survival. MM bone disease (MBD) results from uncoupling of bone remodelling in which excessive bone resorption is not compensated by new bone formation, due to a persistent suppression of osteoblast activity. Current management of MBD includes antiresorptive agents, bisphosphonates and denosumab, that are only partially effective due to their inability to repair the existing lesions. Thus, research into agents that prevent bone destruction and more importantly repair existing lesions by inducing new bone formation is essential. This review discusses the mechanisms regulating the uncoupled bone remodelling in MM and summarizes current advances in the treatment of MBD. LINKED ARTICLES: This article is part of a themed issue on The molecular pharmacology of bone and cancer-related bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.

PDCD1 and PDCD1LG1 polymorphisms affect the susceptibility to multiple myeloma

Single-nucleotide polymorphisms (SNPs) of the programmed cell death protein-1 (PDCD1), programmed cell death protein-1 ligand-1 (PDCD1LG1), and cytotoxic T lymphocyte-associated antigen-4 (CTLA4) genes are implicated in the pathogenesis of some cancers. We investigated the role of PDCD1, PDCD1LG1, and CTLA4 SNPs in MM pathogenesis and the susceptibility to and clinical features of multiple myeloma (MM). We obtained genomic DNA from 124 patients with MM and 211 healthy controls and detected PDCD1 (rs36084323, rs41386349, and rs2227982), PDCD1LG1 (rs2297136 and rs4143815), and CTLA4 (rs733618, rs11571316, rs231775, and rs3087243) genotypes using the polymerase chain reaction-restriction fragment length polymorphism method or the TaqMan allelic discrimination real-time PCR method. The patients with MM had a significantly higher frequency of the PDCD1 GCC/GCC haplotype (rs36084323/rs41386349/rs2227982) compared with the healthy controls. PDCD1 rs2227982 CC genotype was associated significantly with a higher frequency of bone lesions. Patients with PDCD1LG1 rs2297136 TT and TC types (high-expression types) showed lower albumin level than those with CC genotype. In addition, the PDCD1LG1 rs4143815 CC and CG types (high-expression types) were associated significantly with higher frequency of patients who were treated with thalidomide and/or bortezomib. However, there was no statistical significance between CTLA4 polymorphisms and clinical variables of patients with MM. There were no significant differences between all the polymorphisms and OS. Our study indicates that the PDCD1 haplotype is associated with a susceptibility to MM. The PDCD1 rs2227982 and PDCD1LG1 rs2297136 affect the clinical features of multiple myeloma patients.

MicroRNAs and exosomes: Small molecules with big actions in multiple myeloma pathogenesis

Multiple myeloma (MM), an incurable hematologic malignancy of plasma cells increasing in the bone marrow (BM), has a complex microenvironment made to support proliferation, survival, and drug resistance of tumor cells. MicroRNAs (miRNAs), short non-coding RNAs regulating genes expression at posttranscriptional level, have been indicated to be functionally deregulated or abnormally expressed in MM cells. Moreover, by means of miRNAs, tumor microenvironment also modulates the function of MM cells. Consistently, it has been demonstrated that miRNA levels regulation impairs their interaction with the microenvironment of BM as well as create considerable antitumor feature even capable of overcoming the protective BM milieu. Communication between cancer stromal cells and cancer cells is a key factor in tumor progression. Finding out this interaction is important to develop effective approaches that reverse bone diseases. Exosomes, nano-vehicles having crucial roles in cell-to-cell communication, through targeting their cargos (i.e., miRNAs, mRNAs, DNAs, and proteins), are implicated in MM pathogenesis.

Ectopic expression of BIRC5-targeting miR-101-3p overcomes bone marrow stroma-mediated drug resistance in multiple myeloma cells

Background

Multiple myeloma (MM) cells gain protection against drugs through interaction with bone marrow stromal cells (BMSCs). This form of resistance largely accounts for resistance to therapy in MM patients which warrants further exploration to identify more potential therapeutic targets.

Methods

We performed miRNA/mRNA qPCR arrays and western blotting to analyze transcriptional and translational changes in MM cells co-cultured with BMSCs. Drug cytotoxicity and apoptosis in MM^GFP-BMSC co-cultures were measured using fluorescence plate reader and flowcytometry, respectively. miRNA was overexpressed in MM cell lines using Lentiviral transduction, miRNA-3’UTR binding was examined using luciferase assay.

Results

We found that BMSCs downregulated miR-101-3p and upregulated survivin (BIRC5) in MM cells. Survivin was downregulated by miR-101-3p overexpression and found to be a direct target of miR-101-3p using 3’UTR luciferase assay. Overexpression of survivin increased viability of MM cells in the presence of anti-myeloma drugs, and miR-101-3p inhibition by anti-miR against miR-101-3p upregulated survivin. Furthermore, overexpression of miR-101-3p or silencing of survivin triggered apoptosis in MM cells and sensitized them to anti-myeloma drugs in the presence of BMSCs overcoming the stroma-induced drug resistance.

Conclusions

Our study demonstrates that BMSC-induced resistance to drugs is associated with survivin upregulation which is a direct target of miR-101-3p. This study also identifies miR-101-3p-survivin interaction as a druggable target involved in stroma-mediated drug resistance in MM and suggests it for developing more efficient therapeutic strategies.

[miR-202 contributes to sensitizing MM cells to drug significantly via activing JNK/SAPK signaling pathway]

目的

研究microRNA-202（miR-202）对多发性骨髓瘤（MM）细胞生长的影响，并初步探讨miR-202在MM细胞药物敏感性中的作用机制。

方法

荧光定量PCR检测miR-202及其靶基因B淋巴细胞刺激因子（BAFF）在MM细胞中的表达水平。将miR-202模拟物、miR-202抑制物、BAFF干扰质粒（siBAFF）及其阴性对照转染U266细胞，Western blot检测Bcl-2家族和MAPK信号通路蛋白的表达。WST-1法、流式细胞术（Annexin V-FLUOS）分别检测转染后U266细胞的增殖和凋亡情况。

结果

U266细胞、MM患者CD138⁺细胞中miR-202 mRNA表达（分别为0.052±0.009、0.304±0.354）均低于健康对照组（3.550±1.126）（P<0.001，P=0.009），BAFF表达水平（5.700±0.734、9.576±2.887）均高于健康对照组（1.819±0.853）（P<0.001，P=0.006）。miR-202模拟物转染组细胞增殖抑制率高于对照组[（56.04±0.02）％对（18.89±0.32）%，P=0.002]。Western blot结果显示，转染miR-202模拟物后，U266细胞Bcl-2表达下调约24%，而Bax蛋白的表达上调约1.24倍，miR-202模拟物组细胞凋亡率高于对照组[（49.60 ± 4.89）％对（26.20 ± 1.28）%，P=0.029]。硼替佐米和miR-202模拟物联合组细胞凋亡率为（51.23 ± 5.41）%，高于硼替佐米单独处理组（31.70 ± 4.40）％和硼替佐米与模拟物对照联合处理组[（51.23±5.41）％对（31.70±4.40）%，P=0.047；（51.23±5.41）％对（27.94±4.04）%，P=0.028）]，而miR-202模拟物联合沙利度胺和地塞米松与miR-202模拟物对照组相比差异无统计学意义[（11.66±1.91）％对（10.63±1.74）%，P=0.700；（16.35±1.32）％对（17.43±1.95）%，P=0.400]。miR-202模拟物联合硼替佐米对U266细胞的增殖抑制率高于硼替佐米单独处理组[（36.93±5.98）%对（18.18±4.10）%，P=0.029]。miR-202模拟物及硼替佐米处理U266细胞后，p-JNK蛋白表达水平下调。

结论

miR-202模拟物和硼替佐米可协同抑制MM细胞增殖、诱导其凋亡，可能通过miR-202负向调控靶基因BAFF的表达、抑制JNK/SAPK信号通路的活化来实现的。

NRF2 Is One of the Players Involved in Bone Marrow Mediated Drug Resistance in Multiple Myeloma

Multiple myeloma with clonal plasma expansion in bone marrow is the second most common hematologic malignancy in the world. Though the improvement of outcomes from the achievement of novel agents in recent decades, the disease progresses and leads to death eventually due to the elusive nature of myeloma cells and resistance mechanisms to therapeutic agents. In addition to the molecular and genetic basis of resistance pathomechanisms, the bone marrow microenvironment also contributes to disease progression and confers drug resistance in myeloma cells. In this review, we focus on the current state of the literature in terms of critical bone marrow microenvironment components, including soluble factors, cell adhesion mechanisms, and other cellular components. Transcriptional factor nuclear factor erythroid-derived-2-like 2 (NRF2), a central regulator for anti-oxidative stresses and detoxification, is implicated in chemoresistance in several cancers. The functional roles of NRF2 in myeloid-derived suppressor cells and multiple myeloma cells, and the potential of targeting NRF2 for overcoming microenvironment-mediated drug resistance in multiple myeloma are also discussed.

Emerging roles of noncoding RNAs in multiple myeloma: A review

Multiple myeloma (MM) is a hematologic malignancy characterized by unrestricted secretion of monoclonal immunoglobulin and uncontrolled plasma cell proliferation. Extra-medullary infiltration and drug resistance are two major obstacles in the treatment of MM. To solve these problems, it is necessary to elucidate the underlying pathological mechanisms and find new therapeutic targets. Noncoding RNAs (ncRNAs), which were once considered "transcriptional noise," have been recognized as crucial regulators in the process of tumorigenesis including MM. Increasing evidence has shown that ncRNAs participate in MM pathogenesis via a series of complex cellular or extracellular processes. This review article summarizes examples of ncRNAs involved in myelosis and discusses their potential as biomarkers and therapeutic targets in the diagnosis and treatment of myelosis.

Silk Biomaterials-Mediated miRNA Functionalized Orthopedic Devices

Silk-based bioresorbable medical devices, such as screws, plates, and rods, have been under investigation due to their promising properties for orthopedic repairs. Options to functionalize these new devices for enhanced control of bone regeneration would also exploit the compatible processing methods used to generate the devices. MicroRNAs are important regulators of bone maintenance and formation, and miRNA-based therapeutics have the potential to aid bone repair, utilizing a transient therapeutic approach with local bioactivity. We hypothesized that silk-based orthopedic devices could be used for the local delivery of miRNAs, using anti-sense miR-214 (AS-miR-214), to inhibit endogenous expression of osteoinductive antagonist and thereby supporting the upregulation of osteoinductive target molecules activating transcription factor 4 (ATF4) and Osterix (Osx). AS-miR-214 silk devices, prepared using surface coating, demonstrated continuous release of miRNA inhibitors up to 7 days in vitro. Additionally, human mesenchymal stem cells seeded on AS-miR-214 silk films expressed higher levels of osteogenic genes ATF4, Osx, Runx2, and Osteocalcin. Interestingly, these cells exhibited lower cell viability and DNA content over 21 days. Conversely, the cells demonstrated significantly higher levels of alkaline phosphatase expression and calcium deposition compared with cells seeded on silk films with nontargeting miRNA controls. The study demonstrated that the silk-based orthopedic devices, in conjunction with bioactive miRNA-based therapeutics, may serve as a novel system for localized bone tissue engineering, enhancing osteogenesis at the implant interface while avoiding detrimental systematic side effects.

The diagnostic and prognostic value of plasma microRNA-125b-5p in patients with multiple myeloma

Aberrant expression of microRNAs (miRNAs) contributes to the progression and outcomes of several types of tumor, while circulating miRNAs have been reported to act as biomarkers for several types of cancer. To identify specific circulating miRNAs associated with multiple myeloma (MM), a miRNA microarray analysis was used, which identified 8 upregulated miRNAs and 4 downregulated miRNAs in the plasma of 6 patients with MM compared with 6 healthy individuals. Based on the microarray results, the 8 miRNAs (miR-125b-5p, miR-483-3p, miR-4326, miR-6894-3p, miR-4498, miR-490-3p, miR-7155-5p and miR-937-3p), which were notably upregulated in MM patients were chosen for a second clinical study in 20 healthy controls and 35 patients with MM using reverse transcription- quantitative polymerase chain reaction. Receiver operating characteristic analysis demonstrated that miR-125b-5p and miR-490-3p displayed considerable diagnostic accuracy for MM with areas under the curve of 0.954 (P<0.001) and 0.866 (P=0.028), respectively. In addition, the plasma level of miR-125b-5p was associated with the international staging system disease stage. Patients with higher levels of plasma miR-125b-5p had a significantly shorter event-free survival. However, miR-490-3p levels were not associated with event-free survival (P>0.05). In summary, miR-125b-5p may serve as a potential clinical biomarker for MM.

The potential function of microRNAs as biomarkers and therapeutic targets in multiple myeloma

Multiple myeloma (MM), accounting for ~1% of all types of human cancer and 13% of all hematological malignancies, is characterized by the malignant proliferation of monoclonal plasma cells (PCs) in the bone marrow. MM leads to end stage organ impairment, including bone lesions, renal dysfunction, hypercalcemia and anemia. So far, the specific pathogenesis of MM remains unclear and no early-stage sensitive biomarker of MM has been well characterized. Furthermore, treating MM is difficult, as the majority of patients eventually relapse or become refractory following treatment using presently available methods. To date, a number of studies have demonstrated that microRNAs (miRNAs) may serve crucial functions in the progression of numerous cancers, including MM. During the tumorigenesis and pathogenesis of MM, there are multiple carcinogenic events that involve the pernicious transformation from normal to malignant PCs. miRNAs, as oncogenes or tumor suppressors, regulate MM progression-related signaling pathways. In the present review, the up-to-date preliminary basic studies and associated clinical works on the underlying mechanisms of aberrant miRNA profiling in MM have been summarized, including an evaluation of its value as a potential biomarker and a novel therapeutic strategy for MM.

The ceramide pathway is involved in the survival, apoptosis and exosome functions of human multiple myeloma cells in vitro

Multiple myeloma (MM) is characterized by the clonal proliferation of malignant plasma cells and refractoriness to traditional therapies. It has been shown that exosomes are involved in modulating the progression and the metastasis of cancers through microRNAs (miRs). Ceramide is a type of sphingolipid; the ceramide pathway of exosomal secretion has been shown to affect the apoptosis of cancer cells. But the role of this pathway in MM cell function, exosome function and miR regulation remains unknown. In this study, we showed that C6 ceramide (an exogenous ceramide supplement, 1.25-40 μmol/L) dose-dependently inhibited the proliferation and promoted the apoptosis in human MM OPM2 cell line, which were associated with elevated caspase 3/9 and PARP cleavage. We also found that C6 ceramide (5-20 μmol/L) dose-dependently stimulated exosome secretion and increased exosomal levels of tumor-suppressive miRs (miR 202, miR 16, miR 29b and miR 15a). Of note, exosomes from C6 ceramide-treated OPM2 cells could influence the proliferation and apoptosis of the recipient OPM2 cells, which correlated with increased tumor-suppressive exosomal miRs. In contrast, GW4869 (a ceramide inhibitor, 5-20 μmol/L) exerted the opposite effects on the regulation of MM function, exosome secretion and miR levels in MM exosomes. However, exosomes from GW4869-treated OPM2 cells had no effect on these miRs and the survival of targeted OPM2 cells. Taken together, our findings reveal that the ceramide pathway modulates MM survival, probably directly via the caspase pathway and indirectly via exosomal miR mechanisms.

SRC3 expressed in BMSCs promotes growth and migration of multiple myeloma cells by regulating the expression of Cx43

Interactions between bone marrow stromal cells (BMSCs) and multiple myeloma cells significantly contribute to the progression of multiple myeloma (MM). However, little is known about the molecular mechanisms that regulate these interactions. Connexin-43 (Cx-43) has been implicated in the interplay between BMSCs and MM cells. In this study, we hypothesized that the steroid receptor co-activator-3 (SRC3) expressed in BMSCs regulates the expression of Cx-43 to promote the proliferation and migration of myeloma cells. To address this, we co-cultured a human multiple myeloma cell line, RPMI-8226 transfected with either control BMSCs or sh-SRC3-BMSCs. We found that knocking down SRC3 expression in BMSCs inhibited the proliferation and migration of RPMI-8226 cells. In addition, we found that co-culturing RPMI 8266 cells with BMSCs increased Cx43 expression, while knocking down SRC3 expression in BMSCs decreased Cx43 expression. Moreover, our work revealed that SRC3 in BMSCs regulates Cx43 expression via the mitogen-activated protein kinase (MAPK) pathway. To validate this result in vivo, we knocked down SRC3 expression in BMSCs in nude mice and found that tumor growth and cell apoptosis were significantly decreased. In addition, mice treated with either RPMI 8266 cells overexpressing Cx43 or with a P38 MAPK inhibitor (SB202190) exhibited increased intratumoral leukocyte populations and promoted cell apoptosis in tumor tissue. Our findings demonstrate how SRC3 and Cx43 regulation between BMSCs and myeloma cells mediate cell growth and disease progression, with potential implications for prognosis and therapeutic interventions.

miR-202 functions as a tumor suppressor in non-small cell lung cancer by targeting STAT3

MicroRNAs (miRNAs) are a group of non-protein‑coding, short single-stranded RNAs, which are considered as promising molecular markers and therapeutic targets in several cancers. The present study explored the expression patterns and functional roles of miR‑202 in non‑small cell lung cancer (NSCLC). The expression levels of miR‑202 were determined in NSCLC tissues and cell lines using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The functional impact of miR‑202 overexpression on NSCLC cell viability, migration and invasion were evaluated using Cell Counting Kit‑8 reagent and Transwell migration and invasion assays, respectively. The molecular mechanism underlying the tumor suppressive roles of miR‑202 on NSCLC was examined using bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blot analysis. In addition, signal transducer and activator of transcription (STAT) 3 was overexpressed to investigate the impact on miR‑202‑mediated tumor suppression in NSCLC. The results indicated that miR‑202 was downregulated in NSCLC tissues and cell lines, and was associated with tumor node metastasis stage and lymph node metastasis. Exogenous miR‑202 expression reduced NSCLC cell viability, migration and invasion. Furthermore, STAT3 was identified as a direct target gene of miR‑202 in NSCLC. STAT3 overexpression improved miR‑202‑impaired cell viability, migration and invasion. In conclusion, the present study revealed novel anticancer effects induced by miR‑202 upregulation in NSCLC, and indicated that STAT3 may be a molecular target of miR‑202.

MicroRNA Transfer Between Bone Marrow Adipose and Multiple Myeloma Cells

PURPOSE OF REVIEW

Multiple myeloma remains an incurable disease, largely due to the tumor-supportive role of the bone marrow microenvironment. Bone marrow adipose tissue (BMAT) is one component of the fertile microenvironment which is believed to contribute to myeloma progression and drug resistance, as well as participate in a vicious cycle of osteolysis and tumor growth.

RECENT FINDINGS

MicroRNAs (miRNAs) have recently emerged as instrumental regulators of cellular processes that enable the development and dissemination of cancer. This review highlights the intersection between two emerging research fields and pursues the scientific and clinical implications of miRNA transfer between BMAT and myeloma cells. This review provides a concise and provocative summary of the evidence to support exosome-mediated transfer of tumor-supportive miRNAs. The work may prompt researchers to better elucidate the mechanisms by which this novel means of genetic communication between tumor cells and their environment could someday yield targeted therapeutics.

MicroRNAs in multiple myeloma and related bone disease

MicroRNAs (miRNAs) are short non coding RNAs aberrantly expressed in solid and hematopoietic malignancies where they play a pivotal function as post-transcriptional regulators of gene expression. Recent reports have unveiled a central role of miRNAs in multiple myeloma onset and progression and preclinical findings are progressively disclosing their potential therapeutic value as drugs or targets. In this review, we provide the basic insights of miRNA biology and function, showing how these molecules are extensively dysregulated in malignant plasma cells (PC) and related microenvironment, thus favoring clone survival and proliferation. We here describe how these critical activities have recently been evaluated to design miRNA-based therapies against multiple myeloma cells and its surrounding microenvironment.

MicroRNAs: Novel Crossroads between Myeloma Cells and the Bone Marrow Microenvironment

Multiple myeloma (MM) is a hematologic malignancy of differentiated plasma cells that accumulate in the bone marrow, where a complex microenvironment made by different cell types supports proliferation, survival, and drug resistance of tumor cells. MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression at posttranscriptional level. Emerging evidence indicates that miRNAs are aberrantly expressed or functionally deregulated in MM cells as the result of multiple genetic or epigenetic mechanisms and that also the tumor microenvironment regulates MM cell functions by miRNAs. Consistently, modulation of miRNA levels in MM cells has been demonstrated to impair their functional interaction with the bone marrow microenvironment and to produce significant antitumor activity even able to overcome the protective bone marrow milieu. This review will describe the most recent findings on miRNA function in the context of MM bone marrow microenvironment, focusing on the therapeutic potential of miRNA-based approaches.