Role of microRNAs in chronic lymphocytic leukemia (Review)

The role of miRNAs as a big master regulator of signaling pathways involved in lymphoblastic leukemia

MicroRNAs (miRNAs) belong to small noncoding RNAs, which have long attracted researchers' attention because of their potency in acting either as oncogenes or tumor-suppressors in cancers. acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) are two known types of leukemia with high mortality rates in adults and children. On a molecular basis, various signaling pathways are active in both types, making researchers consider the potential role of miRNAs in activating or suppressing these pathways to further hinder cancer development. In this review, we summarized the potential miRNAs, especially circulating ones, involved in essential signaling pathways in the ALL and CLL patients which serve as biomarkers and valuable targets in the treatment fields.

Mitf Involved in Innate Immunity by Activating Tyrosinase-Mediated Melanin Synthesis in Pteria penguin

The microphthalmia-associated transcription factor (MITF) is an important transcription factor that plays a key role in melanogenesis, cell proliferation, survival and immune defense in vertebrate. However, its function and function mechanism in bivalve are still rarely known. In this research, first, a Mitf gene was characterized from Pteria penguin (P. penguin). The PpMitf contained an open reading frame of 1,350 bp, encoding a peptide of 449 deduced amino acids with a highly conserved basic helix-loop-helix-leucine zipper (bHLH-LZ) domain. The PpMITF shared 55.7% identity with amino acid sequence of Crassostrea gigas (C. gigas). Tissue distribution analysis revealed that PpMitf was highly expressed in mantle and hemocytes, which were important tissues for color formation and innate immunity. Second, the functions of PpMitf in melanin synthesis and innate immunity were identified. The PpMitf silencing significantly decreased the tyrosinase activity and melanin content, indicating PpMitf involved in melanin synthesis of P. penguin. Meanwhile, the PpMitf silencing clearly down-regulated the expression of PpBcl2 (B cell lymphoma/leukemia-2 gene) and antibacterial activity of hemolymph supernatant, indicating that PpMitf involved in innate immunity of P. penguin. Third, the function mechanism of PpMitf in immunity was analyzed. The promoter sequence analysis of tyrosinase (Tyr) revealed two highly conserved E-box elements, which were specifically recognized by HLH-LZ of MITF. The luciferase activities analysis showed that Mitf could activate the E-box in Tyr promoter through highly conserved bHLH-LZ domain, and demonstrated that PpMitf involved in melanin synthesis and innate immunity by regulating tyrosinase expression. Finally, melanin from P. penguin, the final production of Mitf-Tyr-melanin pathway, was confirmed to have direct antibacterial activity. The results collectively demonstrated that PpMitf played a key role in innate immunity through activating tyrosinase-mediated melanin synthesis in P. penguin.

MiR-375 inhibits the stemness of breast cancer cells by blocking the JAK2/STAT3 signaling

The relapse of breast cancer could be due to the existence of breast cancer stem cells (BCSCs). Other and our researches have indicated the suppressive roles of miR-375 in various tumors, however, its roles in breast cancer stemness remain confusing. Here, we constructed breast cancer cells with miR-375 stable overexpression via lentivirus infection. Flow cytometry, Western blot, mammosphere formation, cell colony formation and CCK8 as well as in vivo assays were performed to identify the role of miR-375 in the stemness of breast cancer cells. Luciferase reporter, RNA-Fluorescence in situ hybridization (RNA-FISH) and RNA-binding protein immunoprecipitation (RIP) assays were utilized to elucidate the mechanism whereby miR-375 exerts its effects. It was found that miR-375 not only reduced the stemness, but also decreased adriamycin resistance of breast cancer cells. These results were characterized by the decrease of BCSC rate, mammosphere-forming and tumor-initiating ability, and IC50 value of adriamycin, and weakened by JAK2 re-expression. This work indicates that miR-375 suppresses the stemness of breast cancer cells through targeting JAK2.

miRNA-Based Therapies in B Cell Non-Hodgkin Lymphoma

Non-Hodgkin lymphoma (NHL) is a diverse class of hematological cancers, many of which arise from germinal center (GC)-experienced B cells. Thus GCs, the sites of antibody affinity maturation triggered during immune responses, also provide an environment that facilitates B cell oncogenic transformation. miRNAs provide attractive and mechanistically different strategies to treat these malignancies based on their potential for simultaneous modulation of multiple targets. Here, we discuss the scientific rationale for miRNA-based therapeutics in B cell neoplasias and review recent advances that may help establish a basis for novel candidate miRNA-based therapies for B cell-NHL (B-NHL).

Interaction between miRNAs and signaling cascades of Wnt pathway in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL), a severe problem all over the world and represents around 25% of all total leukemia cases, is generating the need for novel targets against CLL. Wnt signaling cascade regulates cell proliferation, differentiation, and cell death processes. Thus, any alteration of the Wnt signaling pathway protein cascade might develop into various types of cancers, either by upregulation or downregulation of the Wnt signaling pathway protein components. In addition, it is reported that activation of the Wnt signaling pathway is associated with the transcriptional activation of microRNAs (miRNAs) by binding to its promoter region, suggesting feedback regulation. Considering the protein regulatory functions of various miRNAs, they can be approached therapeutically as modulatory targets for protein components of the Wnt signaling pathway. In this article, we have discussed the potential role of miRNAs in the regulation of Wnt signaling pathway proteins related to the pathogenesis of CLL via crosstalk between miRNAs and Wnt signaling pathway proteins. This might provide a clear insight into the Wnt protein regulatory function of various miRNAs and provide a better understanding of developing advanced and promising therapeutic approaches against CLL.

Lysosomal autophagy promotes recovery in rats with acute knee injury through TFEB mediation

Background

To study the role of lysosomal decomposition and elimination of old bone matrix, as well as the mechanism of promoting chondrocyte growth and bone recovery through the perspective of TFEB-mediated lysosomal autophagy.

Methods

Rat models of acute knee injury were designed, and autophagy flow was detected by injection of autophagy inhibitors 3-methyladenine. Autophagy flow was detected by RFP-GFP-LC3 double fluorescence molecule. The expression of TFEB, DRAM, MAPLC3, and MITF were analyzed by Western blot, and the expression of genes NITF, Bcl2, and TYR in rat cartilage tissues were detected by RT-PCR.

Results

The number of autophagosomes was increasing in the auto group compared with the inhibitor-auto group and normal group. There was a significant difference of LC3 levels in the auto group and inhibitor-auto group compared with the normal control. The expression of TFEB, DRAM, MAPLC3, and MITF proteins by Western blot analysis were significantly increased in the auto group and decreased in the inhibitor-auto group. The expression of NITF, Bcl2, and TYR by RT-PCR determination were higher in the auto group and inhibitor-auto group than the normal group.

Conclusions

Autophagy can inhibit apoptosis, promote chondrocyte growth and bone regeneration, and restore knee joint injury of rats. The main mechanism is to promote the effect of TFEB-mediated lysosomal autophagy.

Silencing of Long Noncoding RNA SOX21-AS1 Relieves Neuronal Oxidative Stress Injury in Mice with Alzheimer's Disease by Upregulating FZD3/5 via the Wnt Signaling Pathway

Alzheimer's disease (AD) represents a progressive neurodegenerative disorder characterized by distinctive neuropathological changes. Recently, long noncoding RNAs (lncRNAs) have become a key area of interest due to their potential in AD therapy. Hence, the aim of the current study was to investigate the effect of lncRNA SOX21-AS1 on neuronal oxidative stress injury in mice with AD via the Wnt signaling pathway by targeting FZD3/5. Microarray analysis was performed to screen AD-related differentially expressed genes (DEGs). Following verification of the target relationship between SOX21-AS1 and FZD3/5, the contents of OH^-, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were determined, with the expressions of SOX21-AS1, FZD3/5, β-catenin, cyclin D1, and 4-HNE in hippocampal neuron cells subsequently detected. Cell cycle distribution and apoptosis were evaluated. Bioinformatics analysis revealed that SOX21-AS1 was upregulated in AD, while highlighting the co-expression of SOX21-AS1 and FZD3/5 genes and their involvement in the Wnt signaling pathway. AD mice exhibited diminished memory and learning ability, increased rates of MDA, OH^-, SOX21-AS1, 4-HNE, and elevated levels of hippocampal neuron cell apoptosis, accompanied by decreased levels of SOD, CAT, GSH-Px, FZD3/5, β-catenin, and cyclin D1. Silencing of SOX21-AS1 resulted in decreased OH^-, MDA contents, SOX21-AS1, and 4-HNE, and increased SOD, CAT, GSH-Px, FZD3/5, β-catenin, and cyclin D1, as well as reduced apoptosis of hippocampal neuron cells. Taken together, the key findings of the present study demonstrated that silencing of lncRNA SOX21-AS1 could act to alleviate neuronal oxidative stress and suppress neuronal apoptosis in AD mice through the upregulation of FZD3/5 and subsequent activation of the Wnt signaling pathway.

Klotho: a novel biomarker for cancer

BACKGROUND

The Klotho gene was originally identified as an anti-aging gene in 1997. Recent studies have demonstrated aberrant expression of Klotho in a number of cancers, including breast cancer, lung cancer, hepatocellular carcinoma (HCC), and so on.

METHODS

A literature search focusing on dysregulation of Klotho and its possible mechanisms in cancer was performed.

RESULTS AND CONCLUSIONS

Downregulation of Klotho was found in several cancers, such as pancreatic cancer, HCC, and other tumors. Epigenetic modulation, such as promoter methylation and histone deacetylation, also contributed to the dysregulation of Klotho in cancers. Downregulation of Klotho resulted in promoted proliferation and reduced apoptosis of cancer cells. The relevant mechanisms include the fibroblast growth factor signaling, the insulin-like growth factor 1 receptor pathway, and the Wnt/β-catenin signaling pathway. Furthermore, the Klotho protein hopefully provides new insights into cancer target treatment.

microRNAs: role in leukemia and their computational perspective

MicroRNAs (miRNAs) belong to the family of noncoding RNAs (ncRNAs) and had gained importance due to its role in complex biochemical pathways. Changes in the expression of protein coding genes are the major cause of leukemia. Role of miRNAs as tumor suppressors has provided a new insight in the field of leukemia research. Particularly, the miRNAs mediated gene regulation involves the modulation of multiple mRNAs and cooperative action of different miRNAs to regulate a particular gene expression. This highly complex array of regulatory pathway network indicates the great possibility in analyzing and identifying novel findings. Owing to the conventional, slow experimental identification process of miRNAs and their targets, the last decade has witnessed the development of a large amount of computational approaches to deal with the complex interrelations present within biological systems. This article describes the various roles played by miRNAs in regulating leukemia and the role of computational approaches in exploring new possibilities.

Nanopharmacology in translational hematology and oncology

Nanoparticles have displayed considerable promise for safely delivering therapeutic agents with miscellaneous therapeutic properties. Current progress in nanotechnology has put forward, in the last few years, several therapeutic strategies that could be integrated into clinical use by using constructs for molecular diagnosis, disease detection, cytostatic drug delivery, and nanoscale immunotherapy. In the hope of bringing the concept of nanopharmacology toward a viable and feasible clinical reality in a cancer center, the present report attempts to present the grounds for the use of cell-free nanoscale structures for molecular therapy in experimental hematology and oncology.