MiRNAs with prognostic significance in multiple myeloma: A systemic review and meta-analysis

Multiple Myeloma: Genetic and Epigenetic Biomarkers with Clinical Potential

Multiple myeloma (MM) is characterized by the uncontrolled proliferation of monoclonal plasma cells and accounts for approximately 10% of all hematologic malignancies. The clinical outcomes of MM can exhibit considerable variability. Variability in both the genetic and epigenetic characteristics of MM undeniably contributes to tumor dynamics. The aim of the present study was to identify biomarkers with the potential to improve the accuracy of prognosis assessment in MM. Initially, miRNA sequencing was conducted on bone marrow (BM) samples from patients with MM. Subsequently, the expression levels of 27 microRNAs (miRNA) and the gene expression levels of ASF1B, CD82B, CRISP3, FN1, MEF2B, PD-L1, PPARγ, TERT, TIMP1, TOP2A, and TP53 were evaluated via real-time reverse transcription polymerase chain reaction in BM samples from patients with MM exhibiting favorable and unfavorable prognoses. Additionally, the analysis involved the bone marrow samples from patients undergoing examinations for non-cancerous blood diseases (NCBD). The findings indicate a statistically significant increase in the expression levels of miRNA-124, -138, -10a, -126, -143, -146b, -20a, -21, -29b, and let-7a and a decrease in the expression level of miRNA-96 in the MM group compared with NCBD (p < 0.05). No statistically significant differences were detected in the expression levels of the selected miRNAs between the unfavorable and favorable prognoses in MM groups. The expression levels of ASF1B, CD82B, and CRISP3 were significantly decreased, while those of FN1, MEF2B, PDL1, PPARγ, and TERT were significantly increased in the MM group compared to the NCBD group (p < 0.05). The MM group with a favorable prognosis demonstrated a statistically significant decline in TIMP1 expression and a significant increase in CD82B and CRISP3 expression compared to the MM group with an unfavorable prognosis (p < 0.05). From an empirical point of view, we have established that the complex biomarker encompassing the CRISP3/TIMP1 expression ratio holds promise as a prognostic marker in MM. From a fundamental point of view, we have demonstrated that the development of MM is rooted in a cascade of complex molecular pathways, demonstrating the interplay of genetic and epigenetic factors.

CircRNAs in diagnosis, prognosis, and clinicopathological features of multiple myeloma; a systematic review and meta-analysis

Unlike improved treatment response in multiple myeloma (MM), the mortality rate in MM is still high. The study's aim is to investigate the potential role of circRNAs as a new biomarker for diagnosis, prognosis, and clinicopathological features of MM. We identified studies through Web of Science, Scopus, PubMed and ProQuest databases, and Google Scholar to August 2022. The SEN, SPE, PLR, NLR, DOR, and AUC were combined to investigate the diagnostic performance of circRNAs in MM. Also, HR and RR were used for prognostic and clinicopathological indicators, respectively. 12 studies for prognosis, 9 studies about diagnosis, and 13 studies regarding clinicopathological features. The pooled SEN, SPE, DOR, and AUC were 0.82, 0.76, 14.70, and 0.86, respectively for the diagnostic performance of circRNAs. For the prognostic performance, oncogene circRNAs showed a poor prognosis for the patients (HR = 3.71) and tumor suppressor circRNAs indicated a good prognosis (HR = 0.31). Finally, we discovered that dysregulation of circRNAs is associated with poor clinical outcomes in beta-2-microglobulin (RR = 1.56), Durie-Salmon stage (RR = 1.36), and ISS stage (RR = 1.79). Furthermore, the presence of del(17p) and t(4;14) is associated with circRNA dysregulation (RR = 1.44 and 1.44, respectively). Our meta-analysis demonstrates that the expression analysis of circRNAs is valuable for MM's diagnosis and prognosis determination. Also, dysregulation of circRNAs is associated with poor clinicopathological features and can be used as the applicable biomarkers for evaluating treatment effectiveness.

Clinical Significance of microRNAs in Hematologic Malignancies and Hematopoietic Stem Cell Transplantation

Hematologic malignancies are a group of neoplastic conditions that can develop from any stage of the hematopoiesis cascade. Small non-coding microRNAs (miRNAs) play a crucial role in the post-transcriptional regulation of gene expression. Mounting evidence highlights the role of miRNAs in malignant hematopoiesis via the regulation of oncogenes and tumor suppressors involved in proliferation, differentiation, and cell death. In this review, we provide current knowledge about dysregulated miRNA expression in the pathogenesis of hematological malignancies. We summarize data about the clinical utility of aberrant miRNA expression profiles in hematologic cancer patients and their associations with diagnosis, prognosis, and the monitoring of treatment response. Moreover, we will discuss the emerging role of miRNAs in hematopoietic stem cell transplantation (HSCT), and severe post-HSCT complications, such as graft-versus-host disease (GvHD). The therapeutical potential of the miRNA-based approach in hemato-oncology will be outlined, including studies with specific antagomiRs, mimetics, and circular RNAs (circRNAs). Since hematologic malignancies represent a full spectrum of disorders with different treatment paradigms and prognoses, the potential use of miRNAs as novel diagnostic and prognostic biomarkers might lead to improvements, resulting in a more accurate diagnosis and better patient outcomes.

Exosomal miRNAs in the Tumor Microenvironment of Multiple Myeloma

Multiple myeloma (MM) is a malignancy of plasma cells in the bone marrow and is characterized by the clonal proliferation of B-cells producing defective monoclonal immunoglobulins. Despite the latest developments in treatment, drug resistance remains one of the major challenges in the therapy of MM. The crosstalk between MM cells and other components within the bone marrow microenvironment (BME) is the major determinant of disease phenotypes. Exosomes have emerged as the critical drivers of this crosstalk by allowing the delivery of informational cargo comprising multiple components from miniature peptides to nucleic acids. Such material transfers have now been shown to perpetuate drug-resistance development and disease progression in MM. MicroRNAs(miRNAs) specifically play a crucial role in this communication considering their small size that allows them to be readily packed within the exosomes and widespread potency that impacts the developmental trajectory of the disease inside the tumor microenvironment (TME). In this review, we aim to provide an overview of the current understanding of the role of exosomal miRNAs in the epigenetic modifications inside the TME and its pathogenic influence on the developmental phenotypes and prognosis of MM.

The Relationship between Serum miRNAs and Early Mortality in Multiple Myeloma Patients Treated with Bortezomib-Based Regimens

Multiple myeloma (MM) is a hematological malignancy characterized by the clonal proliferation of plasma cells in the bone marrow (BM) microenvironment. Despite the progress made in treatment, some MM patients still die within the first year of diagnosis. Numerous studies investigating microRNA (miRNA) expression patterns suggest they may be good prognostic markers. The primary aim of this study was to analyze the expression of selected miRNAs in the serum of MM patients who were later treated with bortezomib-based regimens, and to determine their potential to predict early mortality. The study was conducted in 70 prospectively recruited patients with newly diagnosed MM admitted to the Department of Hematology of the Copernicus Memorial Hospital, Lodz (Poland) between 2017 and 2021. Among them, 17 patients experienced death within 12 months of diagnosis. The expression of 31 selected miRNAs was determined using a miRCURY LNA miRNA Custom PCR Panel. The obtained clinical data included patient characteristics on diagnosis, treatment regimen, response to treatment, and follow-up. Differential expression analysis found two miRNAs to be significantly downregulated in the early mortality group: hsa-miR-328-3p (fold change-FC: 0.72, p = 0.0342) and hsa-miR-409-3p (FC: 0.49, p = 0.0357). Univariate and multivariate logistic regression analyses were performed to assess the early mortality rate. The final model consisted of hsa-miR-409-3p, hsa-miR-328-3p, age, and R-ISS 3. It yielded an area under the curve (AUC) of 0.863 (95%CI: 0.761-0.965) with 88.2% sensitivity and 77.5% specificity. Further external validation of our model is needed to confirm its clinical value.

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.

Involvement of Small Non-Coding RNA and Cell Antigens in Pathogenesis of Extramedullary Multiple Myeloma

Extramedullary multiple myeloma (EMD) is an aggressive disease; malignant plasma cells lose their dependence in the bone marrow microenvironment and migrate into tissues. EMD is a negative prognostic factor of survival. Using flow cytometry and next-generation sequencing, we aimed to identify antigens and microRNAs (miRNAs) involved in EMD pathogenesis. Flow cytometry analysis revealed significant differences in the level of clonal plasma cells between MM and EMD patients, while the expression of CD markers was comparable between these two groups. Further, miR-26a-5p and miR-30e-5p were found to be significantly down-regulated in EMD compared to MM. Based on the expression of miR-26a-5p, we were able to distinguish these two groups of patients with high sensitivity and specificity. In addition, the involvement of deregulated miRNAs in cell cycle regulation, ubiquitin-mediated proteolysis and signaling pathways associated with infections or neurological disorders was observed using GO and KEGG pathways enrichment analysis. Subsequently, a correlation between the expression of analyzed miRNAs and the levels of CD molecules was observed. Finally, clinicopathological characteristics as well as CD antigens associated with the prognosis of MM and EMD patients were identified. Altogether, we identified several molecules possibly involved in the transformation of MM into EMD.

MiRNA as a Potential Target for Multiple Myeloma Therapy–Current Knowledge and Perspectives

Multiple myeloma (MM) is the second most common hematological malignancy. Despite the huge therapeutic progress thanks to the introduction of novel therapies, MM remains an incurable disease. Extensive research is currently ongoing to find new options. MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression at a post-transcriptional level. Aberrant expression of miRNAs in MM is common. Depending on their role in MM development, miRNAs have been reported as oncogenes and tumor suppressors. It was demonstrated that specific miRNA alterations using miRNA mimics or antagomirs can normalize the gene regulatory network and signaling pathways in the microenvironment and MM cells. These properties make miRNAs attractive targets in anti-myeloma therapy. However, only a few miRNA-based drugs have been entered into clinical trials. In this review, we discuss the role of the miRNAs in the pathogenesis of MM, their current status in preclinical/clinical trials, and the mechanisms by which miRNAs can theoretically achieve therapeutic benefit in MM treatment.

Circulating Serum MiRNA-8074 as a Novel Prognostic Biomarker for Multiple Myeloma

MiRNA-8074 is a molecule with the potential to regulate the expression of key genes related to the pathogenesis of multiple myeloma (MM), i.e., TP53, MYC, MAPK1, and KIAA. We analyzed the predictive and prognostic value of miRNA-8074 expression in MM patients. In total, 105 newly diagnosed MM patients treated with thalidomide (n = 27), bortezomib (n = 41) and bortezomib with thalidomide (n = 37) were studied. For miRNA analysis, the column method and the Real-Time PCR technique with specific TaqMan Fast Advanced Master Mix and TaqMan probes were used. Factors that were associated with a significant reduction in progression-free survival (PFS) included: ECOG > 1, ISS stage III, low hemoglobin, thrombocytopenia, hypoalbuminemia, abnormal renal function, elevated creatinine, GFR < 60 mL/min/1.73 m², elevated LDH, del(17p), t(11;14), the use of a single drug regimen (thalidomide or bortezomib) and high miRNA-8074 expression (HR = 2.01, 95% CI: 1.16–3.49; p = 0.0233). In addition to the known prognostic factors, such as ECOG > 1, Durie–Salmon stage III, diagnosis of light chain disease or non-secreting MM, renal failure, hypoalbuminemia, hypercalcemia, high β2-microglobulin, elevated LDH, and t(14;16), a high expression of miRNA-8074 was significantly associated with a higher risk of death (HR = 4.12, 95% CI: 2.20–7.70; p = 0.0009). In summary, miRNA-8074 may be a useful diagnostic tool to assess the prognosis in MM patients.

miRNAs in the Regulation of Cancer Immune Response: Effect of miRNAs on Cancer Immunotherapy

In the last few decades, carcinogenesis has been extensively explored and substantial research has identified immunogenic involvement in various types of cancers. As a result, immune checkpoint blockers and other immune-based therapies were developed as novel immunotherapeutic strategies. However, despite being a promising therapeutic option, immunotherapy has significant constraints such as a high cost of treatment, unpredictable toxicity, and clinical outcomes. miRNAs are non-coding, small RNAs actively involved in modulating the immune system's multiple signalling pathways by binding to the 3'-UTR of target genes. miRNAs possess a unique advantage in modulating multiple targets of either the same or different signalling pathways. Therefore, miRNA follows a 'one drug multiple target' hypothesis. Attempts are made to explore the therapeutic promise of miRNAs in cancer so that it can be transported from bench to bedside for successful immunotherapeutic results. Therefore, in the current manuscript, we discussed, in detail, the mechanism and role of miRNAs in different types of cancers relating to the immune system, its diagnostic and therapeutic aspect, the effect on immune escape, immune-checkpoint molecules, and the tumour microenvironment. We have also discussed the existing limitations, clinical success and the prospective use of miRNAs in cancer.

New insights into genetic characteristics between multiple myeloma and COVID-19: An integrative bioinformatics analysis of gene expression omnibus microarray and the cancer genome atlas data

Background

Multiple myeloma (MM) is a hematological malignancy. Coronavirus disease 2019 (COVID‐19) infection correlates with MM features. This study aimed to identify MM prognostic biomarkers with potential association with COVID‐19.

Methods

Differentially expressed genes (DEGs) in five MM data sets (GSE47552, GSE16558, GSE13591, GSE6477, and GSE39754) with the same expression trends were screened out. Functional enrichment analysis and the protein‐protein interaction network were performed for all DEGs. Prognosis‐associated DEGs were screened using the stepwise Cox regression analysis in the cancer genome atlas (TCGA) MMRF‐CoMMpass cohort and the GSE24080 data set. Prognosis‐associated DEGs associated with COVID‐19 infection in the GSE164805 data set were also identified.

Results

A total of 98 DEGs with the same expression trends in five data sets were identified, and 83 DEGs were included in the protein‐protein interaction network. Cox regression analysis identified 16 DEGs were associated with MM prognosis in the TCGA cohort, and only the cytochrome c oxidase subunit 6C (COX6C) gene (HR = 1.717, 95% CI 1.231–2.428, p = .002) and the nucleotide‐binding oligomerization domain containing 2 (NOD2) gene (HR = 0.882, 95% CI 0.798–0.975, p = .014) were independent factors related to MM prognosis in the GSE24080 data set. Both of them were downregulated in patients with mild COVID‐19 infection compared with controls but were upregulated in patients with severe COVID‐19 compared with patients with mild illness.

Conclusions

The NOD2 and COX6C genes might be used as prognostic biomarkers in MM. The two genes might be associated with the development of COVID‐19 infection.

MicroRNAs as a Potential New Preventive Approach in the Transition from Asymptomatic to Symptomatic Multiple Myeloma Disease

Simple Summary

Multiple myeloma (MM) is the second most common haematologic malignancy, and it remains an incurable disease despite the advances of novel therapies. It is characterised by a multistep process that arises from a pre-malignant asymptomatic status-defined monoclonal gammopathy of undetermined significance (MGUS), evolves to a middle stage named smouldering myeloma phase (SMM), and culminates in the active disease (MM). Identification of early and non-invasive markers of the disease progression is currently an active field of investigation. In this review, we discuss the role and significance of microRNAs (miRNAs) as potential diagnostic biomarkers to predict the clinical transition from MGUS/SMM status to MM.

Abstract

Multiple myeloma (MM) is a hematological malignancy characterised by proliferation of clonal plasma cells (PCs) within the bone marrow (BM). Myelomagenesis is a multi-step process which goes from an asymptomatic phase, defined as monoclonal gammopathy of undetermined significance (MGUS), to a smouldering myeloma (SMM) stage, to a final active MM disease, characterised by hypercalcemia, renal failure, bone lesions anemia, and higher risk of infections. Overall, microRNAs (miRNAs) have shown to significantly impact on MM tumorigenesis, as a result of miRNA-dependent modulation of genes involved in pathways known to be crucial for MM pathogenesis and disease progression. We aim to revise the literature related to the role of miRNAs as potential diagnostic and prognostic biomarkers, thus highlighting their key role as novel players within the field of MM and related premalignant conditions.

Next-Generation Biomarkers in Multiple Myeloma: Understanding the Molecular Basis for Potential Use in Diagnosis and Prognosis

Multiple myeloma (MM) is considered to be the second most common blood malignancy and it is characterized by abnormal proliferation and an accumulation of malignant plasma cells in the bone marrow. Although the currently utilized markers in the diagnosis and assessment of MM are showing promising results, the incidence and mortality rate of the disease are still high. Therefore, exploring and developing better diagnostic or prognostic biomarkers have drawn global interest. In the present review, we highlight some of the recently reported and investigated novel biomarkers that have great potentials as diagnostic and/or prognostic tools in MM. These biomarkers include angiogenic markers, miRNAs as well as proteomic and immunological biomarkers. Moreover, we present some of the advanced methodologies that could be utilized in the early and competent diagnosis of MM. The present review also focuses on understanding the molecular concepts and pathways involved in these biomarkers in order to validate and efficiently utilize them. The present review may also help in identifying areas of improvement for better diagnosis and superior outcomes of MM.

Plasmacytoma and plasma cell myeloma affecting the jaws: A multi-institutional collaborative study

BACKGROUND

Plasma cell neoplasms are characterized by the proliferation of a single clone of plasma cells with production of a monoclonal immunoglobulin. They can manifest as a single lesion (plasmacytoma) or as multiple lesions (multiple myeloma).

METHODS

Paraffin-embedded tissue blocks of patients microscopically diagnosed with plasma cell neoplasms in the jaws were retrieved from five pathology files. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed and follow-up status were retrieved from the pathology reports.

RESULTS

Fifty-two cases were retrieved (mean age: 59.4 years) without sex predilection. The mandible was the most affected site (67.3%), usually associated with pain and/or paresthesia (53.8%). Lesions in other bones besides the jaws were reported for 24 patients (46.2%). Radiographically, tumours usually presented as poorly defined osteolytic lesions with unilocular or multilocular images, while microscopy revealed diffuse proliferation of neoplastic plasma cells with nuclear displacement and abundant eosinophilic cytoplasm. Two cases were classified as anaplastic, and amyloid deposits were found in two other cases. Immunohistochemistry was positive for plasma cell markers and negative for CD20 and CD3, and monoclonality for kappa light chain predominated. The overall survival rate after 5 years of follow-up was 26.6%.

CONCLUSION

Plasma cell neoplasms are aggressive tumours with a poor prognosis and involvement of the jaws may be the first complaint of the patient. Thus, oral pathologists, head and neck surgeons and dentists should be aware of their clinical, radiographic and microscopic manifestations.

Genome-wide identification of potential biomarkers in multiple myeloma using meta-analysis of mRNA and miRNA expression data

Multiple myeloma (MM) is a plasma cell malignancy with diverse clinical phenotypes and molecular heterogeneity not completely understood. Differentially expressed genes (DEGs) and miRNAs (DEMs) in MM may influence disease pathogenesis, clinical presentation / drug sensitivities. But these signatures overlap meagrely plausibly due to complexity of myeloma genome, diversity in primary cells studied, molecular technologies/ analytical tools utilized. This warrants further investigations since DEGs/DEMs can impact clinical outcomes and guide personalized therapy. We have conducted genome-wide meta-analysis of DEGs/DEMs in MM versus Normal Plasma Cells (NPCs) and derived unified putative signatures for MM. 100 DEMs and 1,362 DEGs were found deranged between MM and NPCs. Signatures of 37 DEMs ('Union 37') and 154 DEGs ('Union 154') were deduced that shared 17 DEMs and 22 DEGs with published prognostic signatures, respectively. Two miRs (miR-16-2-3p, 30d-2-3p) correlated with survival outcomes. PPI analysis identified 5 topmost functionally connected hub genes (UBC, ITGA4, HSP90AB1, VCAM1, VCP). Transcription factor regulatory networks were determined for five seed DEGs with ≥ 4 biomarker applications (CDKN1A, CDKN2A, MMP9, IGF1, MKI67) and three topmost up/ down regulated DEMs (miR-23b, 195, let7b/ miR-20a, 155, 92a). Further studies are warranted to establish and translate prognostic potential of these signatures for MM.

Micro-RNA 122 and micro-RNA 96 affected human osteosarcoma biological behavior and associated with prognosis of patients with osteosarcoma

Osteosarcoma (OS) is the most common bone malignancy in both children and adolescents. In the present study, we aimed to explore the association of miRNA-122 and miRNA-96 expression with the clinical characteristics and prognosis of patients with osteosarcoma. The expression of miRNA-122 and miRNA-96 in human osteosarcoma cell lines and tissues were detected in the present study. Reverse transcriptase-PCR (RT-PCR) was used to determine the expression levels of miRNA-122 and miRNA-96 in 68 human OS samples. We found that MiRNA-122 and miRNA-96 were widely up-regulated in osteosarcoma, gastric cancer and pancreatic cancer. In HOS, Saos-2 and U2OS osteosarcoma cells, miRNA-122 and miRNA-96 were up-regulated significantly, while down-regulated in MG-63 cells. After further investigation, we found that miRNA-122 and miRNA-96 concentrations were significantly higher in the tumor tissues than those in the normal tissues (P<0.01). Moreover, the cell proliferation of LV-miRNA-122-RNAi and LV-miRNA-96-RNAi transfected SaOS2 was significantly decreased compared with the LV- miRNA-122-RNAi-CN and LV- miRNA-96-RNAi group. After adjusting for competing risk factors, we found combined high miRNA-122 and miRNA-96 expression was identified as independent predictor of overall survival.

miR-744-5p Inhibits Multiple Myeloma Proliferation, Epithelial Mesenchymal Transformation and Glycolysis by Targeting SOX12/Wnt/β-Catenin Signaling

Purpose

This study investigated the function and molecular mechanisms of miR-744-5p in multiple myeloma (MM).

Methods

miR-744-5p and SRY-related high-mobility-group box 12 (SOX12) expression in clinical tissues and MM cells was monitored by quantitative real-time polymerase chain reactions and Western blot. miR-744-5p expression in MM cells was regulated by transfection. Cell proliferation was researched by cell counting kit-8 assay and plate clone formation experiment. Transwell experiment was utilized for migration and invasion detection. Glycolysis test was conducted for the detection of glucose uptake and lactate production of MM cells. The relationship between miR-744-5p and SOX12 was determined by dual-luciferase reporter gene assay and RNA pull-down experiment. In vivo experiment was conducted using nude mice.

Results

miR-744-5p expression was reduced in MM patients (P<0.01). Low miR-744-5p expression was associated with lower 60-month survival in MM patients (P=0.0402). miR-744-5p overexpression inhibited MM cells proliferation, invasion, migration, glucose uptake, lactate production, and epithelial mesenchymal transformation (EMT) (P<0.01). miR-744-5p directly inhibited SOX12 expression. miR-744-5p silencing promoted MM cells proliferation, invasion, migration, glucose uptake, lactate production, and EMT by elevating SOX12 (P<0.01). miR-744-5p inhibited the growth of MM xenograft tumors in vivo (P<0.001).

Conclusion

miR-744-5p inhibits MM cells proliferation, invasion, migration, EMT, and glycolysis by targeting SOX12/Wnt/β-catenin.

Diallyl thiosulfinate enhanced the anti-cancer activity of dexamethasone in the side population cells of multiple myeloma by promoting miR-127-3p and deactivating the PI3K/AKT signaling pathway

Background

Side population (SP) cells, which have similar features to those of cancer stem cells, show resistance to dexamethasone (Dex) treatment. Thus, new drugs that can be used in combination with Dex to reduce the population of SP cells in multiple myeloma (MM) are required. Diallyl thiosulfinate (DATS, allicin), a natural organosulfur compound derived from garlic, has been shown to inhibit the proliferation of SP cells in MM cell lines. Therefore, we investigated the effect of a combination of DATS and Dex (DAT + Dex) on MM SP cells.

Methods

SP cells were sorted from MM RPMI-8226 and NCI-H929 cell lines using Hoechst 33342-labeled fluorescence-activated cell sorting. The growth of SP cells was evaluated using the cell counting kit-8 assay. Cell cycle and apoptosis assays were conducted using a BD Calibur flow cytometer. miRNA expression was measured using quantitative reverse transcription-polymerase chain reaction. Phosphoinositide 3-kinase (PI3K), phosphorylated AKT (p-AKT), AKT, p-mechanistic target of rapamycin (mTOR), and mTOR levels were measured using western blot analysis.

Results

Our results showed that the combination of DATS+Dex inhibited sphere formation, colony formation, and proliferation of MM SP cells by inducing apoptosis and cell cycle arrest in the G1/S phase. In addition, the combination of DATS+Dex promoted miR-127-3p expression and inhibited PI3K, p-AKT, and p-mTOR expression in SP cells. Knockdown of miR-127-3p expression weakened the effect of DATS+Dex on cell proliferation, colony formation, apoptosis, and cell cycle of MM SP cells. Additionally, knockdown of miR-127-3p activated the PI3K/AKT/mTOR signaling pathway in MM SP cells cotreated with DATS+Dex.

Conclusion

We demonstrated that cotreatment with DATS+Dex reduced cell proliferation, promoted apoptosis, and caused cell cycle arrest of MM SP cells by promoting miR-127-3p expression and deactivating the PI3K/AKT/mTOR signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07833-5.

Identification of MicroRNAs With In Vivo Efficacy in Multiple Myeloma-related Xenograft Models

BACKGROUND/AIM

Multiple myeloma is a B-cell neoplasm, which can spread within the marrow of the bones forming many small tumors. In advanced disease, multiple myeloma can spread to the blood as plasma cell leukemia. In some cases, a localized tumor known as plasmacytoma is found within a single bone. Despite the approval of several agents such as melphalan, corticosteroids, proteasome inhibitors, thalidomide-based immuno-modulatory agents, histone deacetylase inhibitors, a nuclear export inhibitor and monoclonal antibodies daratuzumab and elatuzumab, the disease presently remains uncurable.

MATERIALS AND METHODS

In order to define new targets and treatment modalities we searched the literature for microRNAs, which increase or inhibit in vivo efficacy in multiple-myeloma-related xenograft models.

RESULTS AND CONCLUSION

We identified six up-regulated and twelve down-regulated miRs, which deserve further preclinical validation.

MicroRNA-92a as a marker of treatment response and survival in adult acute myeloid leukemia patients

This prospective study assessed circulating miR-92a levels in acute myeloid leukemia (AML) at diagnosis and after induction therapy and followed patients for a maximum of 30 months. The study included 63 consecutive adult AML patients. Circulating miR-92a levels were assessed using real-time polymerase chain reaction (RT-PCR). There was significant rise of miR-92a expression after induction (median (range): 0.297 (0.001-3.438)) in comparison to the reported levels at diagnosis (median (range): 0.236 (0.001-3.305)). Post-induction levels of miR-92a are significantly higher in patients who achieved CR in comparison to patients without CR (median (range): 0.408 (0.017-3.438) vs. 0.01 (0.001-1.010), p<.001). Cox hazard regression analysis identified miR-92a as a significant predictor of OS and DFS in univariate and multivariate analyses. In conclusion, baseline circulating miR-92a in AML patients may be a useful prognostic marker of treatment response and survival over 2.5 years follow up.

The Role and Function of microRNA in the Pathogenesis of Multiple Myeloma

Recently, attention has been drawn to the role of non-coding regions of the genome in cancer pathogenesis. MicroRNAs (miRNAs) are small non-coding RNAs with 19–25 bases of length that control gene expression by destroying messenger RNA or inhibiting its translation. In multiple myeloma (MM), the expression of several miRNAs, such as miR-15a and miR-16, is markedly decreased and their target genes upregulated, suggesting their role as tumor-suppressing miRNAs. In contrast, miRNAs such as miR-21 and miR-221 are highly expressed and function as oncogenes (oncomiRs). In addition, several miRNAs, such as those belonging to the miR-34 family, are transcriptional targets of p53 and mediate its tumor-suppressive functions. Many miRNAs are associated with drug resistance, and the modulation of their expression or activity might be explored to reverse it. Moreover, miRNA expression patterns in either MM cells or serum exosomes have been shown to be good prognostic markers. miRNA regulation mechanisms have not been fully elucidated. Many miRNAs are epigenetically controlled by DNA methylation and histone modification, and others regulate the expression of epigenetic modifiers, indicating that miRNA and other epigenetic effectors are part of a network. In this review, we outlined the roles of miRNAs in MM and their potential to predict MM prognosis and develop novel therapies.