MiR-29 Induces K562 Cell Apoptosis by Down-Regulating FoxM1

RNA-based drug discovery for spinal muscular atrophy: a story of small molecules and antisense oligonucleotides

INTRODUCTION

Spinal Muscular Atrophy (SMA), the second most prevalent autosomal genetic disease affecting infants, is caused by the lack of SMN1, which encodes a neuron functioning vital protein, SMN. Improving exon 7 splicing in the paralogous gene SMN2, also coding for SMN protein, increases protein production efficiency from SMN2 to overcome the genetic deficit in SMN1. Several molecular mechanisms have been investigated to improve SMN2 functional splicing.

AREAS COVERED

This manuscript will cover two of the three mechanistically distinct available treatment options for SMA, both targeting the SMN2 splicing mechanism. The first therapeutic, nusinersen (Spinraza®, 2017), is an antisense oligonucleotide (ASO) targeting the splicing inhibitory sequence in the intron downstream of exon 7 from SMN2, thus increasing exon 7 inclusion. The second drug is a small molecule, risdiplam (Evrysdi®, 2021), that enhances the binding of splice factors and also promotes exon 7 inclusion. Both therapies, albeit through different mechanisms, increase full-length SMN protein expression.

EXPERT OPINION

Nusinersen and risdiplam have directly helped SMA patients and families, but they also herald a sea change in drug development for genetic diseases. This piece aims to draw parallels between both development histories; this may help chart the course for future targeted agents.

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.

Overexpression of MicroRNA-10a in Germ Cells Causes Male Infertility by Targeting Rad51 in Mouse and Human

Spermatogenesis is a complicated process including spermatogonial stem cells self-renewal and differentiates into mature spermatozoa. MicroRNAs (miRNAs) as a class of small non-coding RNAs play a crucial role during the process of spermatogenesis. However, the function of a plenty of miRNAs on spermatogenesis and the potential mechanisms remain largely unknown. Here, we show that genetically conditional overexpressed miR-10a in germ cells caused complete male sterility, characterized by meiotic arrested in germ cells. Analysis of miR-10a overexpression mouse testes reveals that failure of double strand break (DSB) repairs and aberrant spermatogonial differentiation. Furthermore, we identified Rad51 as a key target of miR-10a in germ cell by bioinformatics prediction and luciferase assay, which may be responsible for the infertility of the miR-10a overexpressed mice and germ cell arrested patients. Our data show that miR-10a dependent genetic regulation of meiotic process is crucial for male germ cell development and spermatogenesis in both mouse and human. These findings facilitate our understanding of the roles of miRNA-10a in spermatogenesis and male fertility.

Identification and Characterization of microRNAs during Retinoic Acid-Induced Regeneration of a Molluscan Central Nervous System

Retinoic acid (RA) is the biologically active metabolite of vitamin A and has become a well-established factor that induces neurite outgrowth and regeneration in both vertebrates and invertebrates. However, the underlying regulatory mechanisms that may mediate RA-induced neurite sprouting remain unclear. In the past decade, microRNAs have emerged as important regulators of nervous system development and regeneration, and have been shown to contribute to processes such as neurite sprouting. However, few studies have demonstrated the role of miRNAs in RA-induced neurite sprouting. By miRNA sequencing analysis, we identify 482 miRNAs in the regenerating central nervous system (CNS) of the mollusc Lymnaeastagnalis, 219 of which represent potentially novel miRNAs. Of the remaining conserved miRNAs, 38 show a statistically significant up- or downregulation in regenerating CNS as a result of RA treatment. We further characterized the expression of one neuronally-enriched miRNA upregulated by RA, miR-124. We demonstrate, for the first time, that miR-124 is expressed within the cell bodies and neurites of regenerating motorneurons. Moreover, we identify miR-124 expression within the growth cones of cultured ciliary motorneurons (pedal A), whereas expression in the growth cones of another class of respiratory motorneurons (right parietal A) was absent in vitro. These findings support our hypothesis that miRNAs are important regulators of retinoic acid-induced neuronal outgrowth and regeneration in regeneration-competent species.

MicroRNA‑29a contributes to intracranial aneurysm by regulating the mitochondrial apoptotic pathway

Intracranial aneurysm (IA) is an abnormal expansion in the intracranial arteries that weakens the arterial wall by consistently pushing the vascular wall outwards, which leads to a higher risk of aneurysm rupture. A number of reports have demonstrated that apoptosis is associated with the growth and rupture of IA. MicroRNAs (miRNAs/miRs) perform vital roles in the regulation of the mitochondrial apoptotic pathway and signaling proteins. Increasing evidence has already revealed the role of miR‑29a in injury, including liver injury, cardiovascular injury and ischaemia‑reperfusion injury. However, the role of miR‑29a in IA remains unclear at present. The present study investigated the role of miR‑29a in IA pathogenesis and the underlying mechanisms. By using reverse transcription‑quantitative polymerase chain reaction and western blot analysis, the present study demonstrated that genes, including caspase‑3, ‑8 and ‑9, and proteins, including cytochrome c and myeloid cell leukemia 1 (Mcl‑1), involved in mitochondrial apoptosis pathways were upregulated in IA groups compared with controls. In addition, microarray analysis demonstrated that miR‑29a, one of the most altered miRs in IA mice, was overexpressed in IA mice compared with controls. In vitro experiments revealed that miR‑29a downregulation attenuated human brain vascular smooth muscle cell (HBVSMC) apoptosis, while miR‑29a overexpression increased the apoptosis of HBVSMCs. Furthermore, luciferase reporter analysis revealed that Mcl‑1 is a direct target gene of miR‑29a. An in vivo IA model confirmed that miR‑29a overexpression may promote apoptosis through mitochondrial pathways. It was therefore concluded that miR‑29a may contribute to the progression of IA by regulating mitochondrial apoptotic pathways. Thus, miR‑29a is a potential therapeutic target for IA.

Expression and functional characterization of FOXM1 in non-small cell lung cancer

Objectives

FOXM1 is a key member of the FOX transcription factor family, which plays a vital role in a series of physiological processes. In the present study, non-small cell lung cancer (NSCLC) patients and cell lines were studied to explore the correlation between FOXM1 expression and this malignancy.

Materials and methods

The expression status of FOXM1 was detected in 128 cases of NSCLC tissues and NSCLC cell lines. The relationship of FOXM1 expression and clinicopathological features of NSCLC patients was evaluated by us. In addition, we also explored the biological functions of FOXM1 in NSCLC cell lines.

Results

The FOXM1 is highly expressed in NSCLC tissues and cell lines. FOXM1 expression was closely correlated with lymph node status and TNM stage. Cox regression analysis were performed to demonstrate the prognosis role of FOXM1.

Conclusion

FOXM1 conferred a proliferation and invasion advantage to NSCLC cell. The FOXM1 can be regarded as an important molecular marker in NSCLC prognosis.

MicroRNAs as regulators and mediators of forkhead box transcription factors function in human cancers

Evidence has shown that microRNAs are widely implicated as indispensable components of tumor suppressive and oncogenic pathways in human cancers. Thus, identification of microRNA targets and their relevant pathways will contribute to the development of microRNA-based therapeutics. The forkhead box transcription factors regulate numerous processes including cell cycle progression, metabolism, metastasis and angiogenesis, thereby facilitating tumor initiation and progression. A complex network of protein and non-coding RNAs mediates the expression and activity of forkhead box transcription factors. In this review, we summarize the current knowledge and concepts concerning the involvement of microRNAs and forkhead box transcription factors and describe the roles of microRNAs-forkhead box axis in various disease states including tumor initiation and progression. Additionally, we describe some of the technical challenges in the use of the microRNA-forkhead box signaling pathway in cancer treatment.

Large-Scale Analysis of Drug Side Effects via Complex Regulatory Modules Composed of microRNAs, Transcription Factors and Gene Sets

Identifying the occurrence mechanism of drug-induced side effects (SEs) is critical for design of drug target and new drug development. The expression of genes in biological processes is regulated by transcription factors(TFs) and/or microRNAs. Most of previous studies were focused on a single level of gene or gene sets, while studies about regulatory relationships of TFs, miRNAs and biological processes are very rare. Discovering the complex regulating relations among TFs, gene sets and miRNAs will be helpful for researchers to get a more comprehensive understanding about the mechanism of side reaction. In this study, a framework was proposed to construct the relationship network of gene sets, miRNAs and TFs involved in side effects. Through the construction of this network, the potential complex regulatory relationship in the occurrence process of the side effects was reproduced. The SE-gene set network was employed to characterize the significant regulatory SE-gene set interaction and molecular basis of accompanied side effects. A total of 117 side effects complex modules including four types of regulating patterns were obtained from the SE-gene sets-miRNA/TF complex regulatory network. In addition, two cases were used to validate the complex regulatory modules which could more comprehensively interpret occurrence mechanism of side effects.