Promoting effects of MiR-135b on human multiple myeloma cells via regulation of the Wnt/β-catenin/Versican signaling pathway

miR-135b: A key role in cancer biology and therapeutic targets

miR-135b, a microRNA, is consistently up-regulated in various cancer tissues and cells, promoting cancer progression. By inhibiting one or more target genes, miR-135b regulates phenotypes such as cancer growth, apoptosis, migration, invasion, drug resistance, and angiogenesis, establishing it as a critical driver of cancer progression. Additionally, miR-135b is regulated by various oncogenes and therapeutic drugs, highlighting its complexity and therapeutic potential. Significant progress has been made in understanding miR-135b's impact on cancer cell behavior, establishing it as a promising biomarker for cancer diagnosis and prognosis, as well as a potential target for future cancer therapies. However, despite the extensive research on this topic, there has been no comprehensive review summarizing its role and mechanisms across different cancer types. This review aims to provide a detailed overview of the biological characteristics of miR-135b, its regulatory targets, upstream signaling pathways, and its therapeutic potential, including its influence on cancer chemoresistance. The review also addresses key controversies surrounding miR-135b in cancer research, aiming to deepen the understanding of its role, promote the transformation of its clinical application, and provide a theoretical foundation for developing more effective cancer treatment strategies.

PMEPA1 Binds NEDD4L to Inhibit the Malignant Progression of Multiple Myeloma by Inactivating Wnt/β-Catenin Signaling

Multiple myeloma (MM) is an incurable hematological malignancy with increasing prevalence. Prostate transmembrane androgen inducible protein 1 (PMEPA1) is positively associated with overall survival in MM patients, but the exact functions and mechanisms of PMEPA1 in MM have yet to be elucidated. PMEPA1 and neural precursor cell-expressed developmentally downregulated gene 4L (NEDD4L) levels in MM cells were examined. In RPMI-8226 cells with PMEPA1 overexpression or/and NEDD4L knockdown, cell proliferation, cycle distribution and apoptosis were evaluated with the application of CCK-8, EDU staining and flow cytometry. The BioGrid website and HDOCK SERVER were applied for predicting the binding between PMEPA1 and NEDD4L, which was checked by co-immunoprecipitation. Besides, the levels of proteins associated with proliferation (Ki67 and PCNA), apoptosis (Bcl-2, Bax and cleaved caspase3) and Wnt/β-catenin signaling (β-catenin, c-Myc and cyclin D1) was detected with immunoblotting. Finally, LiCl, an activator of Wnt/β-catenin pathway, was employed to treat RPMI-8226 cells to analyze the proliferation, cycle distribution and apoptosis of MM cells. As a result, PMEPA1 and NEDD4L were expressed at low levels in MM cells. PMEPA1 upregulation repressed proliferation induced cycle arrest and facilitated apoptosis of MM cells. Moreover, PMEPA1 bound to NEDD4L and upregulated NEDD4L expression in RPMI-8226 cells. Functionally, NEDD4L knockdown attenuated the influences of PMEPA1 overexpression on the proliferation, cycle distribution and apoptosis of RPMI-8226 cells. Additionally, PMEPA1 notably downregulated β-catenin, c-Myc and cyclin D1 expression in RPMI-8226 cells, which was abrogated by NEDD4L silencing. Further adding LiCl in RPMI-8226 cells led to the enhanced malignant biological behaviors. Collectively, PMEPA1 damaged MM progression through binding NEDD4L to inactivate Wnt/β-catenin signaling, which may be helpful to develop promising targets for MM treatment.

Novel insights into the circ_0003489/let-7b-5p/GLUT1 axis and its possible role in multiple myeloma

BACKGROUND

Circular RNAs (circRNAs) act as vital players in multiple myeloma (MM). Herein, we focused on the function of hsa_circ_0003489 (circ_0003489) in MM development and bortezomib (BTZ) resistance.

METHODS

Relative RNA levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Relative protein levels were evaluated by Western blotting or immunohistochemistry (IHC). The 5'-ethynyl-2'-deoxyuridine (EdU) and cell colony formation (CF) assays were conducted for cell proliferation. Cell counting kit-8 assay was used to evaluate the BTZ resistance. Flow cytometry analysis was performed for cell apoptosis analysis. Glycolysis was determined by detecting the levels of ECAR, glucose consumption, and lactate production. Dual-luciferase reporter and RNA pull-down assays were carried out to analyze the relationships of circ_0003489 with let-7b-5p microRNA and glucose transporter 1 (GLUT1) glucose transporter protein. Xenograft models were conducted to assess the function of circ_0003489 in vivo.

RESULTS

Indeed, as shown by qRT-PCR, bone marrow samples of MM patients showed an upregulation of circ_0003489 RNA in comparison to normal controls (P < 0.0001). In in vitro experiments in MM cells, silencing of circ_0003489 repressed cell proliferation, BTZ resistance, and glycolysis. Furthermore, blocking circ_0003489 facilitated in vitro the apoptosis of MM cells. In vivo experiments showed that silencing circ_0003489 decreased tumor formation. Signaling experiments demonstrated that circ_0003489 sponged let-7b-5p microRNA and negatively regulated let-7b-5p microRNA expression. Loss of let-7b-5p microRNA ameliorated circ_0003489 silencing-mediated effects on MM cell malignant behaviors and BTZ resistance. Moreover, we showed that GLUT1 glucose transporter was targeted by let-7b-5p mircoRNA. GLUT1 enhancement reversed the repressive impacts of let-7b-5p upregulation on MM cell malignant behaviors and BTZ resistance.

CONCLUSION

We suggest that circ_0003489 RNA knockdown inhibited MM progression and reversed BTZ-induced resistance of MM growth by let-7b-5p microRNA regulated function of GLUT1 glucose transporter.

Multiple myeloma: signaling pathways and targeted therapy

Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells, characterized by osteolytic bone lesions, anemia, hypercalcemia, renal failure, and the accumulation of malignant plasma cells. The pathogenesis of MM involves the interaction between MM cells and the bone marrow microenvironment through soluble cytokines and cell adhesion molecules, which activate various signaling pathways such as PI3K/AKT/mTOR, RAS/MAPK, JAK/STAT, Wnt/β-catenin, and NF-κB pathways. Aberrant activation of these pathways contributes to the proliferation, survival, migration, and drug resistance of myeloma cells, making them attractive targets for therapeutic intervention. Currently, approved drugs targeting these signaling pathways in MM are limited, with many inhibitors and inducers still in preclinical or clinical research stages. Therapeutic options for MM include non-targeted drugs like alkylating agents, corticosteroids, immunomodulatory drugs, proteasome inhibitors, and histone deacetylase inhibitors. Additionally, targeted drugs such as monoclonal antibodies, chimeric antigen receptor T cells, bispecific T-cell engagers, and bispecific antibodies are being used in MM treatment. Despite significant advancements in MM treatment, the disease remains incurable, emphasizing the need for the development of novel or combined targeted therapies based on emerging theoretical knowledge, technologies, and platforms. In this review, we highlight the key role of signaling pathways in the malignant progression and treatment of MM, exploring advances in targeted therapy and potential treatments to offer further insights for improving MM management and outcomes.

Decoding the role of miRNAs in multiple myeloma pathogenesis: A focus on signaling pathways

Multiple myeloma (MM) is a cancer of plasma cells that has been extensively studied in recent years, with researchers increasingly focusing on the role of microRNAs (miRNAs) in regulating gene expression in MM. Several non-coding RNAs have been demonstrated to regulate MM pathogenesis signaling pathways. These pathways might regulate MM development, apoptosis, progression, and therapeutic outcomes. They are Wnt/β-catenin, PI3K/Akt/mTOR, P53 and KRAS. This review highlights the impending role of miRNAs in MM signaling and their relationship with MM therapeutic interventions.

Network regulatory mechanism of ncRNA on the Wnt signaling pathway in osteoporosis

Non-coding RNA (ncRNA) is a type of non-protein-coding RNA molecule transcribed from the genome which performs broad regulation of a variety of biological functions in human cells. The Wnt signaling pathway is highly conserved in multicellular organisms, playing an important role in their growth and development. Increasing evidence suggests that ncRNA can regulate cell biological function, enhance bone metabolism, and maintain normal bone homeostasis by interacting with the Wnt pathway. Studies have also demonstrated that the association of ncRNA with the Wnt pathway may be a potential biomarker for the diagnosis, evaluation of prognosis, and treatment of osteoporosis. The interaction of ncRNA with Wnt also performs an important regulatory role in the occurrence and development of osteoporosis. Targeted therapy of the ncRNA/Wnt axis may ultimately be the preferred choice for the treatment of osteoporosis in the future. The current article reviews the mechanism of the ncRNA/Wnt axis in osteoporosis and reveals the relationship between ncRNA and Wnt, thereby exploring novel molecular targets for the treatment of osteoporosis and providing theoretical scientific guidance for its clinical treatment.

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.

Non-coding RNAs and exosomal ncRNAs in multiple myeloma: An emphasis on molecular pathways

One of the most common hematological malignancies is multiple myeloma (MM) that its mortality and morbidity have increased. The incidence rate of MM is suggested to be higher in Europe and various kinds of therapeutic strategies including stem cell transplantation. However, MM treatment is still challenging and gene therapy has been shown to be promising. The non-coding RNAs (ncRNAs) including miRNAs, lncRNAs and circRNAs are considered as key players in initiation, development and progression of MM. In the present review, the role of ncRNAs in MM progression and drug resistance is highlighted to provide new insights for future experiments for their targeting and treatment of MM. The miRNAs affect proliferation and invasion of MM cells, and targeting tumor-promoting miRNAs can induce apoptosis and cell cycle arrest, and reduces proliferation of MM cells. Furthermore, miRNA regulation is of importance for modulating metastasis and chemotherapy response of tumor cells. The lncRNAs exert the same function and determine proliferation, migration and therapy response of MM cells. Notably, lncRNAs mainly target miRNAs in regulating MM progression. The circRNAs also target different molecular pathways in regulating MM malignancy that miRNAs are the most well-known ones. Furthermore, clinical application of ncRNAs in MM is discussed.

Lithium: A Promising Anticancer Agent

Lithium is a therapeutic cation used to treat bipolar disorders but also has some important features as an anti-cancer agent. In this review, we provide a general overview of lithium, from its transport into cells, to its innovative administration forms, and based on genomic, transcriptomic, and proteomic data. Lithium formulations such as lithium acetoacetate (LiAcAc), lithium chloride (LiCl), lithium citrate (Li3C6H5O7), and lithium carbonate (Li2CO3) induce apoptosis, autophagy, and inhibition of tumor growth and also participate in the regulation of tumor proliferation, tumor invasion, and metastasis and cell cycle arrest. Moreover, lithium is synergistic with standard cancer therapies, enhancing their anti-tumor effects. In addition, lithium has a neuroprotective role in cancer patients, by improving their quality of life. Interestingly, nano-sized lithium enhances its anti-tumor activities and protects vital organs from the damage caused by lipid peroxidation during tumor development. However, these potential therapeutic activities of lithium depend on various factors, such as the nature and aggressiveness of the tumor, the type of lithium salt, and its form of administration and dosage. Since lithium has been used to treat bipolar disorder, the current study provides an overview of its role in medicine and how this has changed. This review also highlights the importance of this repurposed drug, which appears to have therapeutic cancer potential, and underlines its molecular mechanisms.

The Wnt/β-catenin signalling pathway in Haematological Neoplasms

Leukaemia and lymphoma are common malignancies. The Wnt pathway is a complex network of proteins regulating cell proliferation and differentiation, as well as cancer development, and is divided into the Wnt/β-catenin signalling pathway (the canonical Wnt signalling pathway) and the noncanonical Wnt signalling pathway. The Wnt/β-catenin signalling pathway is highly conserved evolutionarily, and activation or inhibition of either of the pathways may lead to cancer development and progression. The aim of this review is to analyse the mechanisms of action of related molecules in the Wnt/β-catenin pathway in haematologic malignancies and their feasibility as therapeutic targets.