RNA-binding proteins and exoribonucleases modulating miRNA in cancer: the enemy within

Recent progress in the investigation of microRNA (miRNA) biogenesis and the miRNA processing machinery has revealed previously unknown roles of posttranscriptional regulation in gene expression. The molecular mechanistic interplay between miRNAs and their regulatory factors, RNA-binding proteins (RBPs) and exoribonucleases, has been revealed to play a critical role in tumorigenesis. Moreover, recent studies have shown that the proliferation of hepatocellular carcinoma (HCC)-causing hepatitis C virus (HCV) is also characterized by close crosstalk of a multitude of host RBPs and exoribonucleases with miR-122 and its RNA genome, suggesting the importance of the mechanistic interplay among these factors during the proliferation of HCV. This review primarily aims to comprehensively describe the well-established roles and discuss the recently discovered understanding of miRNA regulators, RBPs and exoribonucleases, in relation to various cancers and the proliferation of a representative cancer-causing RNA virus, HCV. These have also opened the door to the emerging potential for treating cancers as well as HCV infection by targeting miRNAs or their respective cellular modulators.

Heterogeneous genetic patterns in bilateral perisylvian polymicrogyria: insights from a Finnish family cohort

Bilateral perisylvian polymicrogyria is the most common form of regional polymicrogyria within malformations of cortical development, constituting 20% of all malformations of cortical development. Bilateral perisylvian polymicrogyria is characterized by an excessive folding of the cerebral cortex and abnormal cortical layering. Notable clinical features include upper motoneuron dysfunction, dysarthria and asymmetric quadriparesis. Cognitive impairment and epilepsy are frequently observed. To identify genetic variants underlying bilateral perisylvian polymicrogyria in Finland, we examined 21 families using standard exome sequencing, complemented by optical genome mapping and/or deep exome sequencing. Pathogenic or likely pathogenic variants were identified in 5/21 (24%) of families, of which all were confirmed as de novo. These variants were identified in five genes, i.e. DDX23, NUS1, SCN3A, TUBA1A and TUBB2B, with NUS1 and DDX23 being associated with bilateral perisylvian polymicrogyria for the first time. In conclusion, our results confirm the previously reported genetic heterogeneity of bilateral perisylvian polymicrogyria and underscore the necessity of more advanced methods to elucidate the genetic background of bilateral perisylvian polymicrogyria.

MicroRNA-21's role in PTEN suppression and PI3K/AKT activation: Implications for cancer biology

MicroRNA-21 (miR-21) was recognized as a key figure in the intricate web of tumor biology, with a prominent role in regulating the PTEN tumor suppressor gene and the PI3K/AKT cascade. This review elucidates the multifaceted interactions between miR-21, PTEN, and the PI3K/AKT signaling, shedding light on their profound implications in cancer initiation, progression, and therapeutic strategies. The core of this review delves into the mechanical intricacies of miR-21-mediated PTEN suppression and its consequent impact on PI3K/AKT pathway activation. It explores how miR-21, as an oncogenic miRNA, targets PTEN directly or indirectly, resulting in uncontrolled activation of PI3K/AKT, fostering cancerous cell survival, proliferation, and evasion of apoptosis. Furthermore, the abstract emphasizes the clinical relevance of these molecular interactions, discussing their implications in various cancer types, prognostic significance, and potential as therapeutic targets. The review provides insights into ongoing research efforts to develop miR-21 inhibitors and strategies to restore PTEN function, offering new avenues for cancer treatment. This article illuminates the critical function of miR-21 in PTEN suppression and PI3K/AKT activation, offering profound insights into its implications for cancer biology and the potential for targeted interventions.

Ivermectin Inhibits Bladder Cancer Cell Growth and Induces Oxidative Stress and DNA Damage

BACKGROUND

Bladder cancer is the most common malignant tumor of the urinary system. Nevertheless, current therapies do not provide satisfactory results. It is imperative that novel strategies should be developed for treating bladder cancer.

OBJECTIVES

To evaluate the effect of a broad-spectrum anti-parasitic agent, Ivermectin, on bladder cancer cells in vitro and in vivo.

METHODS

CCK-8 and EdU incorporation assays were used to evaluate cell proliferation. Apoptosis was detected by flow cytometry, TUNEL assay, and western blotting. Flow cytometry and DCFH-DA assay were used to analyze the reactive oxygen species (ROS) levels. DNA damage was determined by Neutral COMET assay and γ H2AX expression. Proteins related to apoptosis and DNA damage pathways were determined by WB assay. Xenograft tumor models in nude mice were used to investigate the anti-cancer effect of Ivermectin in vivo.

RESULTS

Our study showed that in vitro and in vivo, Ivermectin inhibited the growth of bladder cancer cells. In addition, Ivermectin could induce apoptosis, ROS production, DNA damage, and activate ATM/P53 pathwayrelated proteins in bladder cancer cells.

CONCLUSIONS

According to these findings, Ivermectin may be a potential therapeutic candidate against bladder cancer due to its significant anti-cancer effect.

Ivermectin as a potential therapeutic strategy for glioma

Ivermectin (IVM), a semi-synthetic macrolide parasiticide, has demonstrated considerable effectiveness in combating internal and external parasites, particularly nematodes and arthropods. Its remarkable ability to control parasites has earned it significant recognition, culminating in Satoshi Omura and William C. Campbell's receipt of the 2015 Nobel Prize in Physiology or Medicine for their contributions to the development of IVM. In recent years, investigations have revealed that IVM possesses antitumor properties. It can suppress the growth of various cancer cells, including glioma, through a multitude of mechanisms such as selective targeting of tumor-specific proteins, inducing programmed cell death, and modulation of tumor-related signaling pathways. Hence, IVM holds tremendous potential as a novel anticancer drug. This review seeks to provide an overview of the underlying mechanisms that enable IVM's capacity to suppress glioma. Furthermore, it aims to elucidate the challenges and prospects associated with utilizing IVM as a new anticancer agent.

Ivermectin induces nonprotective autophagy by downregulating PAK1 and apoptosis in lung adenocarcinoma cells

INTRODUCTION

LUAD (Lung adenocarcinoma), the most common subtype of lung carcinoma and one of the highest incidences and mortality cancers in the world remains still a substantial treatment challenge. Ivermectin, an avermectin derivative, has been traditionally used as an antiparasitic agent in human and veterinary medicine practice during the last few decades. Though ivermectin has been shown to be effective against a variety of cancers, however, there is few available data reporting the antitumor effects of ivermectin in LUAD.

METHODS

The effect of ivermectin on cell viability and proliferative ability of LUAD cells was evaluated using CCK-8 and colony formation assay. Apoptosis rate and autophagy flux were detected using flow cytometry based on PI/Annexin V staining and confocal laser scanning microscope based on LC3-GFP/RFP puncta, respectively. Western blotting experiment was conducted to verify the results of changes in apoptosis and autophagy. LUAD-TCGA and GEO databases were used to analyse the expression and predictive value of PAK1 in LUAD patients. Xenograft model and immumohistochemical staining were used for verification of the inhibitor effect of ivermectin in vivo.

RESULTS

Ivermectin treatment strikingly impeded the colony formation, and the viability of the cell, along with cell proliferation, and caused the apoptosis and enhanced autophagy flux in LUAD cells. In addition, ivermectin-induced nonprotective autophagy was confirmed by treating LUAD cells with 3-MA, an autophagy inhibitor. Mechanistically, we found that ivermectin inhibited PAK1 protein expression in LUAD cells and we confirmed that overexpression of PAK1 substantially inhibited ivermectin-induced autophagy in LUAD cells. Based on TCGA and GEO databases, PAK1 was highly expressed in LUAD tissues as compared with normal tissues. Furthermore, LUAD patients with high PAK1 level have poor overall survival. Finally, in vivo experiments revealed that ivermectin efficiently suppressed the cellular growth of LUAD among nude mice.

CONCLUSION

This study not only revealed the mechanism of ivermectin inhibited the growth of LUAD but also supported an important theoretical basis for the development of ivermectin during the therapy for LUAD.

Cross-talk between PARN and EGFR-STAT3 Signaling Facilitates Self-Renewal and Proliferation of Glioblastoma Stem Cells

Glioblastoma is the most common type of malignant primary brain tumor and displays highly aggressive and heterogeneous phenotypes. The transcription factor STAT3 has been reported to play a key role in glioblastoma malignancy. Thus, discovering targets and functional downstream networks regulated by STAT3 that govern glioblastoma pathogenesis may lead to improved treatment strategies. In this study, we identified that poly(A)-specific ribonuclease (PARN), a key modulator of RNA metabolism, activates EGFR-STAT3 signaling to support glioblastoma stem cells (GSC). Functional integrative analysis of STAT3 found PARN as the top-scoring transcriptional target involved in RNA processing in patients with glioblastoma, and PARN expression was strongly correlated with poor patient survival and elevated malignancy. PARN positively regulated self-renewal and proliferation of GSCs through its 3'-5' exoribonuclease activity. EGFR was identified as a clinically relevant target of PARN in GSCs. PARN positively modulated EGFR by negatively regulating the EGFR-targeting miRNA miR-7, and increased EGFR expression created a positive feedback loop to increase STAT3 activation. PARN depletion in GSCs reduced infiltration and prolonged survival in orthotopic brain tumor xenografts; similar results were observed using siRNA nanocapsule-mediated PARN targeting. Pharmacological targeting of STAT3 also confirmed PARN regulation by STAT3 signaling. In sum, these results suggest that a STAT3-PARN regulatory network plays a pivotal role in tumor progression and thus may represent a target for glioblastoma therapeutics.

SIGNIFICANCE

A positive feedback loop comprising PARN and EGFR-STAT3 signaling supports self-renewal and proliferation of glioblastoma stem cells to drive tumor progression and can be targeted in glioblastoma therapeutics.

Topological Regulating Bismuth Nano-Semiconductor for Immunogenic Cell Death-Mediated Sonocatalytic Hyperthermia Therapy

Immunogenic cell death (ICD) can activate the body's immune system via dead cell antigens to achieve immunotherapy. Currently, small molecule drugs have been used for ICD treatment in clinical, however, how to precisely control the induced ICD while treating tumors is of great significance for improving therapeutic efficacy. Based on this, a sono/light dual response strategy to tumor therapy and activation of ICD is proposed. A topological synthesis method is used to obtain sulfur-doped bismuth oxide Bi2 O3-x Sx (BS) using BiF3 (BF) as a template through reduction and a morphology-controllable bismuth-based nano-semiconductor with a narrow bandgap is constructed. Under the stimulation of ultrasound, BS can produce reactive oxygen species (ROS) through the sonocatalytic process, which cooperates with BS to consume glutathione and enhance cellular oxidative damage, further inducing ICD. Due to the introduction of sulfur in the reduction reaction, BS can achieve photothermal conversion under light, and combine with ROS to treat tumors. Further, with the assistance of ivermectin (IVM) to form composite (BSM), combined with sono/light dual strategy, ICD is promoted and DCs maturation is accelerated. The proposed ICD-mediated hyperthermia/sonocatalytic therapy strategy will pay the way for synergetic enhancement of tumor treatment efficacy and provide a feasible idea for controllable induction of ICD.

Therapeutic vulnerabilities of cancer stem cells and effects of natural products

Covering: 1995 to 2022Tumors possess both genetic and phenotypic heterogeneity leading to the survival of subpopulations post-treatment. The term cancer stem cells (CSCs) describes a subpopulation that is resistant to many types of chemotherapy and which also possess enhanced migratory and anchorage-independent growth capabilities. These cells are enriched in residual tumor material post-treatment and can serve as the seed for future tumor re-growth, at both primary and metastatic sites. Elimination of CSCs is a key goal in enhancing cancer treatment and may be aided by application of natural products in conjunction with conventional treatments. In this review, we highlight molecular features of CSCs and discuss synthesis, structure-activity relationships, derivatization, and effects of six natural products with anti-CSC activity.

Synthetic lethal interactions of DEAD/H-box helicases as targets for cancer therapy

DEAD/H-box helicases are implicated in virtually every aspect of RNA metabolism, including transcription, pre-mRNA splicing, ribosomes biogenesis, nuclear export, translation initiation, RNA degradation, and mRNA editing. Most of these helicases are upregulated in various cancers and mutations in some of them are associated with several malignancies. Lately, synthetic lethality (SL) and synthetic dosage lethality (SDL) approaches, where genetic interactions of cancer-related genes are exploited as therapeutic targets, are emerging as a leading area of cancer research. Several DEAD/H-box helicases, including DDX3, DDX9 (Dbp9), DDX10 (Dbp4), DDX11 (ChlR1), and DDX41 (Sacy-1), have been subjected to SL analyses in humans and different model organisms. It remains to be explored whether SDL can be utilized to identity druggable targets in DEAD/H-box helicase overexpressing cancers. In this review, we analyze gene expression data of a subset of DEAD/H-box helicases in multiple cancer types and discuss how their SL/SDL interactions can be used for therapeutic purposes. We also summarize the latest developments in clinical applications, apart from discussing some of the challenges in drug discovery in the context of targeting DEAD/H-box helicases.

From Molecular Mechanisms to Therapeutics: Understanding MicroRNA-21 in Cancer

MicroRNAs (miRNAs) are small noncoding RNAs that play an important role in regulating gene expression at a posttranscriptional level. As one of the first discovered oncogenic miRNAs, microRNA-21 (miR-21) has been highlighted for its critical role in cancers, such as glioblastoma, pancreatic adenocarcinoma, non-small cell lung cancer, and many others. MiR-21 targets many vital components in a wide range of cancers and acts on various cellular processes ranging from cancer stemness to cell death. Expression of miR-21 is elevated within cancer tissues and circulating miR-21 is readily detectable in biofluids, making it valuable as a cancer biomarker with significant potential for use in diagnosis and prognosis. Advances in RNA-based therapeutics have revealed additional avenues by which miR-21 can be utilized as a promising target in cancer. The purpose of this review is to outline the roles of miR-21 as a key modulator in various cancers and its potential as a therapeutic target.

Ivermectin: A Controversial Focal Point during the COVID-19 Pandemic

The SARS-CoV-2 pandemic has confirmed the apocalyptic predictions that virologists have been making for several decades. The challenge the world is facing is that of trying to find a possible treatment, and a viable and expedient option for addressing this challenge is the repurposing of drugs. However, in some cases, although these drugs are approved for use in humans, the mechanisms of action involved are unknown. In this sense, to justify its therapeutic application to a new disease, it is ideal, but not necessary, to know the basic mechanisms of action involved in a drug’s biological effects. This review compiled the available information regarding the various effects attributed to Ivermectin. The controversy over its use for the treatment of COVID-19 is demonstrated by this report that considers the proposal unfeasible because the therapeutic doses proposed to achieve this effect cannot be achieved. However, due to the urgent need to find a treatment, an exhaustive and impartial review is necessary in order to integrate the knowledge that exists, to date, of the possible mechanisms through which the treatment may be helpful in defining safe doses and schedules of Ivermectin.

RNA Helicases in Microsatellite Repeat Expansion Disorders and Neurodegeneration

Short repeated sequences of 3-6 nucleotides are causing a growing number of over 50 microsatellite expansion disorders, which mainly present with neurodegenerative features. Although considered rare diseases in relation to the relatively low number of cases, these primarily adult-onset conditions, often debilitating and fatal in absence of a cure, collectively pose a large burden on healthcare systems in an ageing world population. The pathological mechanisms driving disease onset are complex implicating several non-exclusive mechanisms of neuronal injury linked to RNA and protein toxic gain- and loss- of functions. Adding to the complexity of pathogenesis, microsatellite repeat expansions are polymorphic and found in coding as well as in non-coding regions of genes. They form secondary and tertiary structures involving G-quadruplexes and atypical helices in repeated GC-rich sequences. Unwinding of these structures by RNA helicases plays multiple roles in the expression of genes including repeat-associated non-AUG (RAN) translation of polymeric-repeat proteins with aggregating and cytotoxic properties. Here, we will briefly review the pathogenic mechanisms mediated by microsatellite repeat expansions prior to focus on the RNA helicases eIF4A, DDX3X and DHX36 which act as modifiers of RAN translation in C9ORF72-linked amyotrophic lateral sclerosis/frontotemporal dementia (C9ORF72-ALS/FTD) and Fragile X-associated tremor/ataxia syndrome (FXTAS). We will further review the RNA helicases DDX5/17, DHX9, Dicer and UPF1 which play additional roles in the dysregulation of RNA metabolism in repeat expansion disorders. In addition, we will contrast these with the roles of other RNA helicases such as DDX19/20, senataxin and others which have been associated with neurodegeneration independently of microsatellite repeat expansions. Finally, we will discuss the challenges and potential opportunities that are associated with the targeting of RNA helicases for the development of future therapeutic approaches.

Splicing Factor DDX23, Transcriptionally Activated by E2F1, Promotes Ovarian Cancer Progression by Regulating FOXM1

Ovarian carcinoma remains the most lethal gynecological carcinoma. Abnormal expression of splicing factors is closely related to the occurrence and development of tumors. The DEAD-box RNA helicases are important members of the splicing factor family. However, their role in the occurrence and progression of ovarian cancer is still unclear. In this study, we identified DEAD-box helicase 23 (DDX23) as a key DEAD-box RNA helicase in ovarian cancer using bioinformatics methods. We determined that DDX23 was upregulated in ovarian cancer and its high expression predicted poor prognosis. Functional assays indicated that DDX23 silencing significantly impeded cell proliferation/invasion in vitro and tumor growth in vivo. Mechanistically, transcriptomic analysis showed that DDX23 was involved in mRNA processing in ovarian cancer cells. Specifically, DDX23 regulated the mRNA processing of FOXM1. DDX23 silencing reduced the production of FOXM1C, the major oncogenic transcript of FOXM1 in ovarian cancer, thereby decreasing the FOXM1 protein expression and attenuating the malignant progression of ovarian cancer. Rescue assays indicated that FOXM1 was a key executor in DDX23-induced malignant phenotype of ovarian cancer. Furthermore, we confirmed that DDX23 was transcriptionally activated by the transcription factor (TF) E2F1 in ovarian cancer using luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays. In conclusion, our study demonstrates that high DDX23 expression is involved in malignant behavior of ovarian cancer and DDX23 may become a potential target for precision therapy of ovarian cancer.

Repositioning Ivermectin for Covid-19 treatment: Molecular mechanisms of action against SARS-CoV-2 replication

Ivermectin (IVM) is an FDA approved macrocyclic lactone compound traditionally used to treat parasitic infestations and has shown to have antiviral potential from previous in-vitro studies. Currently, IVM is commercially available as a veterinary drug but have also been applied in humans to treat onchocerciasis (river blindness - a parasitic worm infection) and strongyloidiasis (a roundworm/nematode infection). In light of the recent pandemic, the repurposing of IVM to combat SARS-CoV-2 has acquired significant attention. Recently, IVM has been proven effective in numerous in-silico and molecular biology experiments against the infection in mammalian cells and human cohort studies. One promising study had reported a marked reduction of 93% of released virion and 99.98% unreleased virion levels upon administration of IVM to Vero-hSLAM cells. IVM's mode of action centres around the inhibition of the cytoplasmic-nuclear shuttling of viral proteins by disrupting the Importin heterodimer complex (IMPα/β1) and downregulating STAT3, thereby effectively reducing the cytokine storm. Furthermore, the ability of IVM to block the active sites of viral 3CLpro and S protein, disrupts important machinery such as viral replication and attachment. This review compiles all the molecular evidence to date, in review of the antiviral characteristics exhibited by IVM. Thereafter, we discuss IVM's mechanism and highlight the clinical advantages that could potentially contribute towards disabling the viral replication of SARS-CoV-2. In summary, the collective review of recent efforts suggests that IVM has a prophylactic effect and would be a strong candidate for clinical trials to treat SARS-CoV-2.

The role of microRNA-21 in the onset and progression of cancer

MicroRNAs (miRNAs), a class of small noncoding RNA, posttranscriptionally regulate the expression of genes. Aberrant expression of miRNA is reported in various types of cancer. Since the first report of oncomiR-21 involvement in the glioma, its upregulation was reported in multiple cancers and was allied with high oncogenic property. In addition to the downregulation of tumor suppressor genes, the miR-21 is also associated with cancer resistance to various chemotherapy. The recent research is appraising miR-21 as a promising cancer target and biomarker for early cancer detection. In this review, we briefly explain the biogenesis and regulation of miR-21 in cancer cells. Additionally, the review features the assorted genes/pathways regulated by the miR-21 in various cancer and cancer stem cells.

Syndromic neurodevelopmental disorder associated with de novo variants in DDX23

The DEAD/DEAH box RNA helicases are a superfamily of proteins involved in the processing and transportation of RNA within the cell. A growing literature supports this family of proteins as contributing to various types of human disorders from neurodevelopmental disorders to syndromes with multiple congenital anomalies. This article presents a cohort of nine unrelated individuals with de novo missense alterations in DDX23 (Dead-Box Helicase 23). The gene is ubiquitously expressed and functions in RNA splicing, maintenance of genome stability, and the sensing of double-stranded RNA. Our cohort of patients, gathered through GeneMatcher, exhibited features including tone abnormalities, global developmental delay, facial dysmorphism, autism spectrum disorder, and seizures. Additionally, there were a variety of other findings in the skeletal, renal, ocular, and cardiac systems. The missense alterations all occurred within a highly conserved RecA-like domain of the protein, and are located within or proximal to the DEAD box sequence. The individuals presented in this article provide evidence of a syndrome related to alterations in DDX23 characterized predominantly by atypical neurodevelopment.

Heartworm disease - Overview, intervention, and industry perspective

Dirofilaria immitis, also known as heartworm, is a major parasitic threat for dogs and cats around the world. Because of its impact on the health and welfare of companion animals, heartworm disease is of huge veterinary and economic importance especially in North America, Europe, Asia and Australia. Within the animal health market many different heartworm preventive products are available, all of which contain active components of the same drug class, the macrocyclic lactones. In addition to compliance issues, such as under-dosing or irregular treatment intervals, the occurrence of drug-resistant heartworms within the populations in the Mississippi River areas adds to the failure of preventive treatments. The objective of this review is to provide an overview of the disease, summarize the current disease control measures and highlight potential new avenues and best practices for treatment and prevention.

Transcription/Replication Conflicts in Tumorigenesis and Their Potential Role as Novel Therapeutic Targets in Multiple Myeloma

Simple Summary

Multiple myeloma is a hematologic cancer characterized by the accumulation of malignant plasma cells in the bone marrow. It remains a mostly incurable disease due to the inability to overcome refractory disease and drug-resistant relapse. Oncogenic transformation of PC in multiple myeloma is thought to occur within the secondary lymphoid organs. However, the precise molecular events leading to myelomagenesis remain obscure. Here, we identified genes involved in the prevention and the resolution of conflicts between the replication and transcription significantly overexpressed during the plasma cell differentiation process and in multiple myeloma cells. We discussed the potential role of these factors in myelomagenesis and myeloma biology. The specific targeting of these factors might constitute a new therapeutic strategy in multiple myeloma.

Abstract

Plasma cells (PCs) have an essential role in humoral immune response by secretion of antibodies, and represent the final stage of B lymphocytes differentiation. During this differentiation, the pre-plasmablastic stage is characterized by highly proliferative cells that start to secrete immunoglobulins (Igs). Thus, replication and transcription must be tightly regulated in these cells to avoid transcription/replication conflicts (TRCs), which could increase replication stress and lead to genomic instability. In this review, we analyzed expression of genes involved in TRCs resolution during B to PC differentiation and identified 41 genes significantly overexpressed in the pre-plasmablastic stage. This illustrates the importance of mechanisms required for adequate processing of TRCs during PCs differentiation. Furthermore, we identified that several of these factors were also found overexpressed in purified PCs from patients with multiple myeloma (MM) compared to normal PCs. Malignant PCs produce high levels of Igs concomitantly with cell cycle deregulation. Therefore, increasing the TRCs occurring in MM cells could represent a potent therapeutic strategy for MM patients. Here, we describe the potential roles of TRCs resolution factors in myelomagenesis and discuss the therapeutic interest of targeting the TRCs resolution machinery in MM.

Repurposing of Antimicrobial Agents for Cancer Therapy: What Do We Know?

The substantial costs of clinical trials, the lengthy timelines of new drug discovery and development, along the high attrition rates underscore the need for alternative strategies for finding quickly suitable therapeutics agents. Given that most approved drugs possess more than one target tightly linked to other diseases, it encourages promptly testing these drugs in patients. Over the past decades, this has led to considerable attention for drug repurposing, which relies on identifying new uses for approved or investigational drugs outside the scope of the original medical indication. The known safety of approved drugs minimizes the possibility of failure for adverse toxicology, making them attractive de-risked compounds for new applications with potentially lower overall development costs and shorter development timelines. This latter case is an exciting opportunity, specifically in oncology, due to increased resistance towards the current therapies. Indeed, a large body of evidence shows that a wealth of non-cancer drugs has beneficial effects against cancer. Interestingly, 335 drugs are currently being evaluated in different clinical trials for their potential activities against various cancers (Redo database). This review aims to provide an extensive discussion about the anti-cancer activities exerted by antimicrobial agents and presents information about their mechanism(s) of action and stage of development/evaluation.

Application of carbohydrates in approved small molecule drugs: A review

Carbohydrates are an important energy source and play numerous key roles in all living organisms. Carbohydrates chemistry involved in diagnosis and treatment of diseases has been attracting increasing attention. Carbohydrates could be one of the major focuses of new drug discovery. Currently, however, carbohydrate-containing drugs account for only a small percentage of all drugs in clinical use, which does not match the important roles of carbohydrates in the organism. In other words, carbohydrates are a relatively untapped source of new drugs and therefore may offer exciting novel therapeutic opportunities. Here, we presented an overview of the application of carbohydrates in approved small molecule drugs and emphasized and evaluated the roles of carbohydrates in those drugs. The potential development direction of carbohydrate-containing drugs was presented after summarizing the advantages and challenges of carbohydrates in the development of new drugs.

DEAD-BOX RNA HELICASE 27 regulates microRNA biogenesis, zygote division, and stem cell homeostasis

After double fertilization, zygotic embryogenesis initiates a new life cycle, and stem cell homeostasis in the shoot apical meristem (SAM) and root apical meristem (RAM) allows plants to produce new tissues and organs continuously. Here, we report that mutations in DEAD-BOX RNA HELICASE 27 (RH27) affect zygote division and stem cell homeostasis in Arabidopsis (Arabidopsis thaliana). The strong mutant allele rh27-1 caused a zygote-lethal phenotype, while the weak mutant allele rh27-2 led to minor defects in embryogenesis and severely compromised stem cell homeostasis in the SAM and RAM. RH27 is expressed in embryos from the zygote stage, and in both the SAM and RAM, and RH27 is a nucleus-localized protein. The expression levels of genes related to stem cell homeostasis were elevated in rh27-2 plants, alongside down-regulation of their regulatory microRNAs (miRNAs). Further analyses of rh27-2 plants revealed reduced levels of a large subset of miRNAs and their pri-miRNAs in shoot apices and root tips. In addition, biochemical studies showed that RH27 associates with pri-miRNAs and interacts with miRNA-biogenesis components, including DAWDLE, HYPONASTIC LEAVES 1, and SERRATE. Therefore, we propose that RH27 is a component of the microprocessor complex and is critical for zygote division and stem cell homeostasis.

Ivermectin Increases Random-Pattern Skin Flap Survival in Rats: The Novel Role of GABAergic System

BACKGROUND

Ivermectin (IVM) was first used as an antiparasitic agent; however, the role of this drug evolved into a broad spectrum. Many mechanisms have been proposed, including interaction with the GABAergic system. Considering the presence of GABA receptor in the skin tissue and its role in ischemia-reperfusion I/R injury, we aimed to evaluate the effect of IVM through GABA receptors on random-pattern skin flap survival.

METHODS

Sixty Wistar male rats were used. Multiple doses of IVM (0.01, 0.05, 0.2, and 0.5 mg/kg) were injected intraperitoneally before the surgery. Baclofen (selective GABAB agonist) and bicuculline (selective GABAA antagonist) were administered in combination with IVM to assess the role of the GABAergic system. Histopathological evaluations, immunohistochemical staining, quantitative assessment of IL-1β and TNFα, and the expression of GABAA α1 subunit and GABAB R1 receptors were evaluated in the skin tissue.

RESULTS

IVM 0.05 mg/kg could significantly increase flap survival compared with the control group (P < 0.001). Subeffective dose of baclofen (0.1 mg/kg) had synergistic effect with the subeffective dose of IVM (0.01 mg/kg) (P < 0.001), whereas bicuculline 1 mg/kg reversed the effect of IVM (0.05 mg/kg) (P < 0.001). IVM 0.05 mg/kg could also decrease the IL-1β and TNFα levels and increase the expression of GABAA α1 subunit and GABAB R1 receptors in the flap tissue compared with the control group.

CONCLUSIONS

IVM could improve skin flap survival, probably mediated by the GABAergic pathway. Both GABAA and GABAB receptors are involved in this process. This finding may repurpose the use of old drug, "Ivermectin."

The Role of the U5 snRNP in Genetic Disorders and Cancer

Pre-mRNA splicing is performed by the spliceosome, a dynamic macromolecular complex consisting of five small uridine-rich ribonucleoprotein complexes (the U1, U2, U4, U5, and U6 snRNPs) and numerous auxiliary splicing factors. A plethora of human disorders are caused by genetic variants affecting the function and/or expression of splicing factors, including the core snRNP proteins. Variants in the genes encoding proteins of the U5 snRNP cause two distinct and tissue-specific human disease phenotypes – variants in PRPF6, PRPF8, and SNRP200 are associated with retinitis pigmentosa (RP), while variants in EFTUD2 and TXNL4A cause the craniofacial disorders mandibulofacial dysostosis Guion-Almeida type (MFDGA) and Burn-McKeown syndrome (BMKS), respectively. Furthermore, recurrent somatic mutations or changes in the expression levels of a number of U5 snRNP proteins (PRPF6, PRPF8, EFTUD2, DDX23, and SNRNP40) have been associated with human cancers. How and why variants in ubiquitously expressed spliceosome proteins required for pre-mRNA splicing in all human cells result in tissue-restricted disease phenotypes is not clear. Additionally, why variants in different, yet interacting, proteins making up the same core spliceosome snRNP result in completely distinct disease outcomes – RP, craniofacial defects or cancer – is unclear. In this review, we define the roles of different U5 snRNP proteins in RP, craniofacial disorders and cancer, including how disease-associated genetic variants affect pre-mRNA splicing and the proposed disease mechanisms. We then propose potential hypotheses for how U5 snRNP variants cause tissue specificity resulting in the restricted and distinct human disorders.

The RNA-Binding Protein DDX18 Promotes Gastric Cancer by Affecting the Maturation of MicroRNA-21

Objectives

The noncoding RNAs (ncRNAs) play important roles in gastric cancer. Most studies have focused on the functions and influence of ncRNAs, but seldom on their maturation. DEAD box genes are a family of RNA-binding proteins that may influence the development of ncRNAs, which attracted our attention. By combining a small sample for high-throughput gene microarray screening with large samples of The Cancer Genome Atlas (TCGA) data and our cohort, we aimed to find some gastric cancer-related genes. We evaluated the clinical significance and prognostic value of candidate gene DDX18, which is overexpressed in gastric cancer tissues. To provide a theoretical basis for the development of new therapeutic targets for the treatment of gastric cancer, we investigated its effect on the malignant biological behavior of gastric cancer in vitro and in vivo, and also discuss its mechanism of action.

Methods

(i) The differential profiling of mRNA expression in five pairs of gastric cancer and adjacent normal tissues was studied by Arraystar Human mRNA Microarray. By combining this with TCGA data and our cohort, we finally filtered out DDX18, which was upregulated in gastric cancer tissues, for further investigation. (ii) The protein expression of DDX18 was detected by immunohistochemistry staining. Then the relationship between the DDX18 expression level and the clinicopathological data and prognosis was analyzed. (iii) A CCK-8 assay and colony formation assay were used to evaluate the effect of DDX18 on cell growth and proliferation in vitro. A transwell assay was also performed to examine the migration and invasion of gastric cancer cells. Cell apoptosis was analyzed by using a fluorescein isothiocyanate–annexin V/propidium iodide double-staining assay. To identify the role of DDX18 in the tumorigenic ability of gastric cancer cells in vivo, we also established a subcutaneous gastric cancer xenograft model. Coimmunoprecipitation, small RNAseq, and western blotting were performed to explore the mechanism of action of DDX18 in gastric cancer. A patient-derived xenograft (PDX) model was used to confirm the effect of DDX18 in gastric cancer tissues.

Result

(i) DDX18 was upregulated in gastric cancer tumor tissues from a TCGA database and our cohort. The expression of DDX18 was also closely related to tumor volume, Borrmann classification, degree of tumor differentiation, cancer embolus, lymph node metastasis, and TNM stage. (ii) DDX18 could promote cell proliferation, migration, and invasion and inhibit cell apoptosis in vivo and in vitro. (iii) DDX18 could promote the maturation of microRNA-21 through direct interaction with Drosha, decreasing PTEN, which could upregulate the AKT signaling pathway. (iv) The PDX model showed that DDX18 could promote the proliferation of gastric cancer tissues by means of the PTEN–AKT signaling pathway.

Conclusions

(i) DDX18 can be treated as a molecular marker to assess the prognosis of patients with gastric cancer. (ii) DDX18 could be a potential therapeutic target in gastric cancer.

Molecular Signature of Extracellular Vesicular Small Non-Coding RNAs Derived from Cerebrospinal Fluid of Leptomeningeal Metastasis Patients: Functional Implication of miR-21 and Other Small RNAs in Cancer Malignancy

Simple Summary

Leptomeningeal metastasis (LM) is a lethal complication in which cancer metastasizes to the meninges. Currently, there are neither definitive treatments nor diagnosis methods for LM patients. In this study, we suggest the examination of small non-coding RNA (smRNA) populations of extracellular vesicles (EVs) derived from the cerebrospinal fluid (CSF) as a potential vehicle for diagnosis and treatment strategies. Systemic and quantitative analysis of smRNA subpopulations from LM CSF EVs showed unique expression patterns between LM patients and healthy donors. In addition, LM CSF EVs smRNAs appeared to be associated with LM pathogenesis suggesting they may be viable targets for novel diagnostic and treatment strategies.

Abstract

Leptomeningeal metastasis (LM) is a fatal and rare complication of cancer in which the cancer spreads via the cerebrospinal fluid (CSF). At present, there is no definitive treatment or diagnosis for this deleterious disease. In this study, we systemically and quantitatively investigated biased expression of key small non-coding RNA (smRNA) subpopulations from LM CSF extracellular vesicles (EVs) via a unique smRNA sequencing method. The analyzed subpopulations included microRNA (miRNA), Piwi-interacting RNA (piRNA), Y RNA, small nuclear RNA (snRNA), small nucleolar RNAs (snoRNA), vault RNA (vtRNA), novel miRNA, etc. Here, among identified miRNAs, miR-21, which was already known to play an essential oncogenic role in tumorigenesis, was thoroughly investigated via systemic biochemical, miR-21 sensor, and physiological cell-based approaches, with the goal of confirming its functionality and potential as a biomarker for the pathogenesis and diagnosis of LM. We herein uncovered LM CSF extravesicular smRNAs that may be associated with LM-related complications and elucidated plausible pathways that may mechanistically contribute to LM progression. In sum, the analyzed smRNA subpopulations will be useful as targets for the development of therapeutic and diagnostic strategies for LM and LM-related complications.

Oncogenic ZEB2/miR-637/HMGA1 signaling axis targeting vimentin promotes the malignant phenotype of glioma

Glioma is the most common primary tumor of the central nervous system. We previously confirmed that zinc finger E-box binding homeobox (ZEB) 2 promotes the malignant progression of glioma, while microRNA-637 (miR-637) is associated with favorable prognosis in glioma. This study aimed to investigate the potential interaction between ZEB2 and miR-637 and its downstream signaling pathway in glioma. The results revealed that ZEB2 could directly bind to the E-box elements in the miR-637 promoter and promote cell proliferation, migration, and invasion via miR-637 downregulation. Subsequent screening confirmed that HMGA1 was a direct target of miR-637, while miR-637 could drive the malignant phenotype of glioma by suppressing HMGA1 both in vitro and in vivo. Furthermore, interaction between cytoplasmic HMGA1 and vimentin was observed, and vimentin inhibition could abolish increased migration and invasion induced by HMGA1 overexpression. Both HMGA1 and vimentin were associated with an unfavorable prognosis in glioma. Additionally, upregulated HMGA1 and vimentin were found in isocitrate dehydrogenase (IDH) wild-type and 1p/19q non-codeletion diffusely infiltrating glioma. In conclusion, we identified an oncogenic ZEB2/miR-637/HMGA1 signaling axis targeting vimentin that promotes both migration and invasion in glioma.

SILAC quantitative proteomics analysis of ivermectin-related proteomic profiling and molecular network alterations in human ovarian cancer cells

The antiparasitic agent ivermectin offers more promises to treat a diverse range of diseases. However, a comprehensive proteomic analysis of ivermectin-treated ovarian cancer (OC) cells has not been performed. This study sought to identify ivermectin-related proteomic profiling and molecular network alterations in human OC cells. Stable isotope labeling with amino acids in cell culture (SILAC)-based quantitative proteomics was used to study the human OC TOV-21G cells. After TOV-21G cells underwent 10 passages in SILAC-labeled growth media, TOV-21G cells were treated with 10 ml of 20 μmol/L ivermectin in cell growing medium for 24 h. The SILAC-labeled proteins were digested with trypsin; tryptic peptides were identified with mass spectrometry (MS). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was used to mine signaling pathway alterations with ivermectin-related proteins in TOV-21G cells. Gene ontology (GO) analysis was used to explore biological functions of ivermectin-related proteins, including biological processes (BPs), cellular components (CCs), and molecular functions (MFs). The protein-protein interaction network was analyzed with molecular complex detection (MCODE) to identify hub modules. In total, 4,447 proteins were identified in ivermectin-treated TOV-21G cells. KEGG analysis revealed 89 statistically significant signaling pathways. Interestingly, the clustering analysis of these pathways showed that ivermectin was involved in various cancer pathogenesis processes, including modulation of replication, RNA metabolism, and translational machinery. GO analysis revealed 69 statistically significant CCs, 87 MFs, and 62 BPs. Furthermore, MCODE analysis identified five hub modules, including 147 hub molecules. Those hub modules involved ribosomal proteins, RNA-binding proteins, cell-cycle progression-related proteins, proteasome subunits, and minichromosome maintenance proteins. These findings demonstrate that SILAC quantitative proteomics is an effective method to analyze ivermectin-treated cells, provide the first ivermectin-related proteomic profiling and molecular network alterations in human OC cells, and provide deeper insights into molecular mechanisms and functions of ivermectin to inhibit OC cells.

Ivermectin, a potential anticancer drug derived from an antiparasitic drug

Ivermectin is a macrolide antiparasitic drug with a 16-membered ring that is widely used for the treatment of many parasitic diseases such as river blindness, elephantiasis and scabies. Satoshi ōmura and William C. Campbell won the 2015 Nobel Prize in Physiology or Medicine for the discovery of the excellent efficacy of ivermectin against parasitic diseases. Recently, ivermectin has been reported to inhibit the proliferation of several tumor cells by regulating multiple signaling pathways. This suggests that ivermectin may be an anticancer drug with great potential. Here, we reviewed the related mechanisms by which ivermectin inhibited the development of different cancers and promoted programmed cell death and discussed the prospects for the clinical application of ivermectin as an anticancer drug for neoplasm therapy.

Development of a miRNA-controlled dual-sensing system and its application for targeting miR-21 signaling in tumorigenesis

MicroRNAs (miRNAs) are considered to be strong prognostic markers and key therapeutic targets in human diseases, especially cancer. A sensitive monitoring platform for cancer-associated miRNA (oncomiR) action is needed for mechanistic studies, preclinical evaluation, and inhibitor screening. In this study, we developed and systemically applied a sensitive and efficient lentivirus-based system for monitoring oncomiR actions, essentially miR-21. The specificity and sensitivity of “miRDREL” against various oncomiRs were validated by checking for tight correlations between their expression and targeting efficacy. Experiments based on the transfection of synthetic mimics and antagomir-mediated depletion of oncomiRs further confirmed the specificity of the system. Systemic application of miRDRELs to natural oncomiR targets, knockdown of key microprocessors, and physiological triggering of oncomiRs also demonstrated that the system is an effective tool for monitoring cellular oncomiR action. Importantly, molecular modeling-based screening confirmed the action of the miR-21-targeting drug ivermectin and led to the identification of a new effective derivative, GW4064, for inhibiting oncogenic DDX23-miR-21 signaling. Furthermore, proteomic-kinase inhibitor screenings identified a novel oncogenic kinome-DDX23-miR-21 axis and thus expands our understanding of miR-21 targeting therapeutics in tumorigenesis. Taken together, these data indicate that miRDREL and its versatile application have great potential in basic, preclinical studies and drug development pipelines for miRNA-related diseases, especially cancer.

A new method for monitoring microRNAs (miRNAs), very short RNA molecules that regulate gene expression, shows promise for developing and testing new cancer therapies. These miRNAs are strongly implicated in cancer, and are used for diagnosis and as therapeutic targets. However, currently available systems for monitoring them are inefficient and lack capacity for scaling up. Jong Heon Kim and co-workers at the National Cancer Center in Goyang, South Korea, have developed a new miRNA monitoring method that can be used in multiple disease models, including long-term experiments in small animals. They used the method to clarify how the cancer drug ivermectin acts, to identify a molecule similar to ivermectin but that may be more effective, and to identify novel molecules that interact with cancer-related miRNAs. This method shows promise for both clinical and basic research applications.

DNA helicases and their roles in cancer

DNA helicases, known for their fundamentally important roles in genomic stability, are high profile players in cancer. Not only are there monogenic helicase disorders with a strong disposition to cancer, it is well appreciated that helicase variants are associated with specific cancers (e.g., breast cancer). Flipping the coin, DNA helicases are frequently overexpressed in cancerous tissues and reduction in helicase gene expression results in reduced proliferation and growth capacity, as well as DNA damage induction and apoptosis of cancer cells. The seminal roles of helicases in the DNA damage and replication stress responses, as well as DNA repair pathways, validate their vital importance in cancer biology and suggest their potential values as targets in anti-cancer therapy. In recent years, many laboratories have characterized the specialized roles of helicase to resolve transcription-replication conflicts, maintain telomeres, mediate cell cycle checkpoints, remodel stalled replication forks, and regulate transcription. In vivo models, particularly mice, have been used to interrogate helicase function and serve as a bridge for preclinical studies that may lead to novel therapeutic approaches. In this review, we will summarize our current knowledge of DNA helicases and their roles in cancer, emphasizing the latest developments.

Avermectin Derivatives, Pharmacokinetics, Therapeutic and Toxic Dosages, Mechanism of Action, and Their Biological Effects

Avermectins are a group of drugs that occurs naturally as a product of fermenting Streptomyces avermitilis, an actinomycetes, isolated from the soil. Eight different structures, including ivermectin, abamectin, doramectin, eprinomectin, moxidectin, and selamectin, were isolated and divided into four major components (A1a, A2a, B1a and B2a) and four minor components (A1b, A2b, B1b, and B2b). Avermectins are generally used as a pesticide for the treatment of pests and parasitic worms as a result of their anthelmintic and insecticidal properties. Additionally, they possess anticancer, anti-diabetic, antiviral, antifungal, and are used for treatment of several metabolic disorders. Avermectin generally works by preventing the transmission of electrical impulse in the muscle and nerves of invertebrates, by amplifying the glutamate effects on the invertebrates-specific gated chloride channel. Avermectin has unwanted effects or reactions, especially when administered indiscriminately, which include respiratory failure, hypotension, and coma. The current review examines the mechanism of actions, biosynthesis, safety, pharmacokinetics, biological toxicity and activities of avermectins.

DDX39 Overexpression Predicts a Poor Prognosis and Promotes Aggressiveness of Melanoma by Cooperating With SNAIL

This study aimed to investigate the prognostic value and molecular mechanism of DDX39 and its effector SNAIL in melanoma. First, overexpression of DDX39 in melanoma, which was identified by database analysis, was further validated in patient tissues. Cell growth, cell cycle, cell migration, and cell invasion assays were then performed to evaluate the effects of downregulated DDX39 on the melanoma cell proliferation and aggressiveness. The same approaches were also used to reveal the cooperation of the transcription factor SNAIL with DDX39 to promote the aggressiveness of melanoma cells. We found that the expression of DDX39 was significantly upregulated in melanoma tissue compared to pigmented nevus tissue, and it was positively correlated with the clinical stage defined by the American Joint Committee on Cancer (AJCC) and the prognosis. Downregulation of DDX39 in melanoma cells was found to significantly inhibit cell proliferation, increase G2/M cell cycle arrest, enhance caspase-mediated cell apoptosis, and suppress cell invasion and migration. In addition, we demonstrated that the overexpression of SNAIL could restore the cell growth and aggressiveness impaired by DDX39 RNA interference. Immunohistochemical staining also showed a positive correlation between DDX39 overexpression and SNAIL overexpression in melanoma tissues, suggesting that SNAIL is one of the effectors activated by DDX39. In summary, the overexpression of DDX39 and SNAIL was positively related to the poor prognosis of melanoma patients and the increased aggressiveness of melanoma cells. Our study provides valuable evidence regarding the prognostic value of DDX39 and SNAIL as well as their potential as novel therapeutic targets for treating melanoma patients.

ARS2/MAGL signaling in glioblastoma stem cells promotes self-renewal and M2-like polarization of tumor-associated macrophages

The interplay between glioblastoma stem cells (GSCs) and tumor-associated macrophages (TAMs) promotes progression of glioblastoma multiforme (GBM). However, the detailed molecular mechanisms underlying the relationship between these two cell types remain unclear. Here, we demonstrate that ARS2 (arsenite-resistance protein 2), a zinc finger protein that is essential for early mammalian development, plays critical roles in GSC maintenance and M2-like TAM polarization. ARS2 directly activates its novel transcriptional target MGLL, encoding monoacylglycerol lipase (MAGL), to regulate the self-renewal and tumorigenicity of GSCs through production of prostaglandin E₂ (PGE₂), which stimulates β-catenin activation of GSC and M2-like TAM polarization. We identify M2-like signature downregulated by which MAGL-specific inhibitor, JZL184, increased survival rate significantly in the mouse xenograft model by blocking PGE₂ production. Taken together, our results suggest that blocking the interplay between GSCs and TAMs by targeting ARS2/MAGL signaling offers a potentially novel therapeutic option for GBM patients.

Anti-parasite drug ivermectin can suppress ovarian cancer by regulating lncRNA-EIF4A3-mRNA axes

RELEVANCE

Ivermectin, as an old anti-parasite drug, can suppress almost completely the growth of various human cancers, including ovarian cancer (OC). However, its anticancer mechanism remained to be further studied at the molecular levels. Ivermectin-related molecule-panel changes will serve a useful tool for its personalized drug therapy and prognostic assessment in OCs.

PURPOSE

To explore the functional significance of ivermectin-mediated lncRNA-EIF4A3-mRNA axes in OCs and ivermectin-related molecule-panel for its personalized drug therapy monitoring.

METHODS

Based on our previous study, a total of 16 lncRNA expression patterns were analyzed using qRT-PCR before and after ivermectin-treated different OC cell lines (TOV-21G and A2780). Stable isotope labeling with amino acids in cell culture (SILAC)-based quantitative proteomics was used to analyze the protein expressions of EIF4A3 and EIF4A3-binding mRNAs in ovarian cancer cells treated with and without ivermectin. A total of 411 OC patients from the Cancer Genome Atlas (TCGA) database with the selected lncRNA expressions and the corresponding clinical data were included. Lasso regression was constructed to examine the relationship between lncRNA signature and OC survival risk. The overall survival analysis between high-risk and low-risk groups used the Kaplan-Meier method. Heatmap showed the correlation between risk groups and clinical characteristics. The univariate and multivariate models were established with Cox regression.

RESULTS

SILAC-based quantitative proteomics found the protein expression levels of EIF4A3 and 116 EIF4A3-binding mRNAs were inhibited by ivermectin in OC cells. Among the analyzed 16 lncRNAs (HCG15, KIF9-AS1, PDCD4-AS1, ZNF674-AS1, ZNRF3-AS1, SOS1-IT1, LINC00565, SNHG3, PLCH1-AS1, WWTR1-AS1, LINC00517, AL109767.1, STARD13-IT1, LBX2-AS1, LEMD1-AS1, and HOXC-AS3), only 7 lncRNAs (HCG15, KIF9-AS1, PDCD4-AS1, ZNF674-AS1, ZNRF3-AS1, SOS1-IT1, and LINC00565) were obtained for further lasso regression when combined with the results of drug testing and overall survival analysis. Lasso regression identified the prognostic model of ivermectin-related three-lncRNA signature (ZNRF3-AS1, SOS1-IT1, and LINC00565). The high-risk and low-risk groups based on the prognostic model were significantly related to overall survival and clinicopathologic characteristics (survival status, lymphatic invasion, cancer status, and clinical stage) in OC patients and remained independent risk factors according to multivariate COX analysis (p < 0.05).

CONCLUSION

Those findings provided the potential targeted lncRNA-EIF4A3-mRNA pathways of ivermectin in OC, and constructed the effective prognostic model, which benefits discovery of novel mechanism of ivermectin to suppress ovarian cancer cells, and the ivermectin-related molecule-panel changes benefit for its personalized drug therapy and prognostic assessment towards its predictive, preventive, and personalized medicine (PPPM) in OCs.

Antitumor effects of ivermectin at clinically feasible concentrations support its clinical development as a repositioned cancer drug

PURPOSE

Ivermectin is an antiparasitic drug that exhibits antitumor effects in preclinical studies, and as such is currently being repositioned for cancer treatment. However, divergences exist regarding its employed doses in preclinical works. Therefore, the aim of this study was to determine whether the antitumor effects of ivermectin are observable at clinically feasible drug concentrations.

METHODS

Twenty-eight malignant cell lines were treated with 5 μM ivermectin. Cell viability, clonogenicity, cell cycle, cell death and pharmacological interaction with common cytotoxic drugs were assessed, as well as the consequences of its use on stem cell-enriched populations. The antitumor in vivo effects of ivermectin were also evaluated.

RESULTS

The breast MDA-MB-231, MDA-MB-468, and MCF-7, and the ovarian SKOV-3, were the most sensitive cancer cell lines to ivermectin. Conversely, the prostate cancer cell line DU145 was the most resistant to its use. In the most sensitive cells, ivermectin induced cell cycle arrest at G₀-G₁ phase, with modulation of proteins associated with cell cycle control. Furthermore, ivermectin was synergistic with docetaxel, cyclophosphamide and tamoxifen. Ivermectin reduced both cell viability and colony formation capacity in the stem cell-enriched population as compared with the parental one. Finally, in tumor-bearing mice ivermectin successfully reduced both tumor size and weight.

CONCLUSION

Our results on the antitumor effects of ivermectin support its clinical testing.

Ivermectin suppresses tumour growth and metastasis through degradation of PAK1 in oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (ESCC), the most common form of oesophageal malignancies in the Asia‐Pacific region, remains a major clinical challenge. In this study, we found that ivermectin, an effective antiparasitic drug that has been approved for patients to orally treat onchocerciasis for over 30 years, displayed potent antitumour activity against ESCC cells in vitro and in nude mice. We demonstrated that ivermectin significantly inhibited cell viability and colony formation, and induced apoptosis through a mitochondrial‐dependent manner in ESCC cells. Ivermectin also abrogated ESCC cell migration, invasion, as well as the protein levels of MMP‐2 and MMP‐9. Mechanistically, ivermectin strongly inhibited the expression of PAK1; by further gain‐ and loss‐of‐function experiments, we confirmed that PAK1 played a crucial role in ivermectin‐mediated inhibitory effects on ESCC cells. In addition, the data indicated that ivermectin promoted PAK1 degradation through the proteasome‐dependent pathway. Additionally, ivermectin synergized with chemotherapeutic drugs including cisplatin and 5‐fluorouracil to induce apoptosis of ESCC cells. Interestingly, the in vivo experiments also confirmed that ivermectin effectively suppressed tumour growth and lung metastasis of ESCC. Collectively, these results indicate that ivermectin exerts a potent antitumour activity against ESCC and is a promising therapeutic candidate drug for ESCC patients, even those carrying metastasis.

Progress in Understanding the Molecular Mechanisms Underlying the Antitumour Effects of Ivermectin

Ivermectin, a dihydro derivative of avermectin (AVM), was introduced into the veterinary, agricultural and aquaculture markets for animal health in 1981. Ivermectin was soon adopted in 1987 as a human medicine that was originally used for the treatment of onchocerciasis, a parasitic infection. Since then, ivermectin has also been used to control other human diseases and has exerted a significant effect on human health and welfare. In the past decade, many published studies have attempted to determine the role of ivermectin in cancer. In this review, we summarize the published studies to define the current progress in the characterization of ivermectin. Ivermectin causes cell death in cancer cell lines by inducing PAK1-mediated cytostatic autophagy, caspase-dependent apoptosis and immunogenic cell death (ICD) through the modulation of some pathways, including the WNT-T cell factor (TCF), Hippo and Akt/mTOR pathways. Ivermectin can affect the growth and proliferation of cancer cells and plays several different roles, such as its functions as an RNA helicase, a small-molecule mimetic of the surface-induced dissociation (SID) peptide, an activator of chloride channel receptors, and an inducer of mitochondrial dysfunction and oxidative stress. In addition, ivermectin induces the multidrug resistance protein (MDR), has potent anti-mitotic activity, targets angiogenesis and inhibits cancer stem-like cells (CSCs). Many studies have proven that ivermectin exerts antitumour effects and might thus benefit patients with cancer after sufficient clinical trials.

SMA1, a homolog of the splicing factor Prp28, has a multifaceted role in miRNA biogenesis in Arabidopsis

MicroRNAs (miRNAs) are a class of small non-coding RNAs that repress gene expression. In plants, the RNase III enzyme Dicer-like (DCL1) processes primary miRNAs (pri-miRNAs) into miRNAs. Here, we show that SMALL1 (SMA1), a homolog of the DEAD-box pre-mRNA splicing factor Prp28, plays essential roles in miRNA biogenesis in Arabidopsis. A hypomorphic sma1-1 mutation causes growth defects and reduces miRNA accumulation correlated with increased target transcript levels. SMA1 interacts with the DCL1 complex and positively influences pri-miRNA processing. Moreover, SMA1 binds the promoter region of genes encoding pri-miRNAs (MIRs) and is required for MIR transcription. Furthermore, SMA1 also enhances the abundance of the DCL1 protein levels through promoting the splicing of the DCL1 pre-mRNAs. Collectively, our data provide new insights into the function of SMA1/Prp28 in regulating miRNA abundance in plants.

Overview upon miR-21 in lung cancer: focus on NSCLC

Considering the high mortality rate encountered in lung cancer, there is a strong need to explore new biomarkers for early diagnosis and also improved therapeutic targets to overcome this issue. The implementation of microRNAs as important regulators in cancer and other pathologies expanded the possibilities of lung cancer management and not only. MiR-21 represents an intensively studied microRNA in many types of cancer, including non-small cell lung cancer (NSCLC). Its role as an oncogene is underlined in multiple studies reporting the upregulated expression of this sequence in patients diagnosed with this malignancy; moreover, several studies associated this increased expression of miR-21 with a worse outcome within NSCLC patients. The same pattern is supported by the data existent in the Cancer Genome Atlas (TCGA). The carcinogenic advantage generated by miR-21 in NSCLC resides in the target genes involved in multiple pathways such as cell growth and proliferation, angiogenesis, invasion and metastasis, but also chemo- and radioresistance. Therapeutic modulation of miR-21 by use of antisense sequences entrapped in different delivery systems has shown promising results in impairment of NSCLC. Hereby, we review the mechanisms of action of miR-21 in cancer and the associated changes upon tumor cells together a focused perspective on NSCLC signaling, prognosis and therapy.

Ivermectin inhibits the growth of glioma cells by inducing cell cycle arrest and apoptosis in vitro and in vivo

Glioma, the most predominant primary malignant brain tumor, remains uncured due to the absence of effective treatments. Hence, it is imperative to develop successful therapeutic agents. This study aimed to explore the antitumor effects and mechanisms of ivermectin (IVM) in glioma cells in vitro and in vivo. The effects of IVM on cell viability, cell cycle arrest, apoptosis rate, and morphological characteristics were determined respectively by MTT assay/colony formation assay, flow cytometry, and transmission electron microscope. In addition, the expression levels of cycle-related and apoptosis-associated proteins were individually examined by Western blot analysis. Moreover, cell proliferation and apoptosis analyses were carried out by TUNEL, Ki-67, cleaved caspase-3, and cleaved caspase-9 immunostaining assay. Our results demonstrated that IVM has a potential dosage-dependent inhibition effect on the apoptosis rate of glioma cells. Meanwhile, the results also revealed that IVM induced apoptosis by increasing caspase-3 and caspase-9 activity, upregulating the expressions of p53 and Bax, downregulating Bcl-2, activating cleaved caspase-3 and cleaved caspase-9, and blocking cell cycle in G0/G1 phase by downregulating levels of CDK2, CDK4, CDK6, cyclin D1, and cyclin E. These findings suggest that IVM has an inhibition effect on the proliferation of glioma cells by triggering cell cycle arrest and inducing cell apoptosis in vitro and in vivo, and probably represents promising agent for treating glioma.

DDX23-Linc00630-HDAC1 axis activates the Notch pathway to promote metastasis

Emerging studies demonstrated the roles of long non-coding RNAs (LncRNAs) are being implicated in the progression of many cancers. Here we report the discovery of a critical role for the linc00630 in the development of Non-Small-Cell Lung Cancers (NSCLCs). Screening from the microarray of six paired NSCLCs and adjacent non-tumor tissues, linc00630 showed a significantly higher RNA levels in NSCLCs. With the higher level confirmed in a separate cohort 90 NSCLCs patients, overexpressed of linc00630 also positive associated with tumor size, TNM tumor stage, lymph node status positive and overall patient outcomes. Linc00630 overexpression increased cell proliferation and metastasis in vitro and in vivo whereas linc00630 silencing had opposite effects. By RNA pull-down and mass spectrometry we identified Histone deacetylases 1 (HDAC1) and DEAD-box helicase 23 (DDX23) as the linc00630-binding protein that associated with mechanism of linc00630. DDX23 can specific bind with the promoter of Linc00630 to up-regulate the RNA level and high level of linc00630 strength the protein stability of HDAC1 to regulate the downstream pathway.

Our study demonstrates the effectiveness of Linc00630 oligonucleotide-based promotion of NSCLCs metastasis and proliferation, illuminating a new basis of DDX23-Linc00630-HDAC1 signal axis for understanding its pathogenicity, which could be further developed as a valuable therapeutic strategy.

Subsite-specific association of DEAD box RNA helicase DDX60 with the development and prognosis of oral squamous cell carcinoma

The clinical significance and biological function of DEXD/H box helicase 60 (DDX60) in oral cancer remains unknown. Herein, we evaluated the association of DDX60 expression with tumorigenesis and the prognosis of oral squamous cell carcinoma (OSCC). DDX60 expression was examined by immunohistochemistry on tissue microarray slides of 494 OSCC patients, including 180 buccal mucosal SCC (BMSCC), 241 tongue SCC (TSCC), and 73 lip SCC (LSCC) patients. DDX60 expression was significantly increased in all three subsites of OSCC compared to its expression in tumor adjacent normal tissues. However, its association with tumorigenesis was specific to the oral cavity subsite after the stratification of betel quid chewing, smoking, and drinking. Among OSCC patients, higher levels of DDX60 expression were associated with the male gender, a well-differentiated tumor, advanced stage of disease, and a large tumor size with subsite specific features. LSCC patients with high DDX60 expression levels showed shorter disease-specific survival, particularly those with moderately or poorly differentiated tumors. Additionally, TSCC or OSCC patients with high DDX60 expression showed a poor disease-free survival (DFS), particularly those with moderately or poorly differentiated tumors. Therefore, DDX60 is a novel and unfavorable biomarker for tumorigenesis and prognosis of OSCC in a subsite-specific manner.

TRIM71 suppresses tumorigenesis via modulation of Lin28B-let-7-HMGA2 signaling

TRIM71 (tripartite motif-containing 71) belongs to the TRIM-NHL protein family, which plays a conserved role in regulating early development and differentiation. However, the molecular functions of TRIM71 have remained largely unknown. Here, we explored the role of TRIM71 together with modulation of Lin28B-let-7-HMGA2 (high-mobility group AT-hook 2) signaling in tumorigenesis. TRIM71 overexpression opposed Lin28B-induced transformation in primary cells and inhibited tumor formation in a mouse model. Specific knockdown of TRIM71 expression increased cancer cell proliferation and invasion. Conversely, overexpression of wild-type TRIM71 in non-small cell lung carcinoma (NSCLC) cells in which Lin28B-let-7-HMGA2 signaling was conserved decreased both cancer cell phenotypes. More importantly, overexpression of an ubiquitin transfer activity-deficient TRIM71 mutant in NSCLC cells had no effect on proliferation or invasion, regardless of the conservation status of Lin28B-let-7-HMGA2 signaling. The tumorigenic inhibitory action of TRIM71 was antagonized by overexpression of the TRIM71 downstream targets, Lin28B and HMGA2. Furthermore, a bioinformatics analysis revealed that TRIM71 expression was downregulated in various types of cancer tissue from patients. Taken together, these data indicate that TRIM71 acts through post-transcriptional repression of Lin28B and subsequent modulation of let-7-HMGA2 signaling during tumorigenesis to potentially function as a tumor suppressor.

Long Noncoding RNA UCA1 Targets miR-122 to Promote Proliferation, Migration, and Invasion of Glioma Cells

Glioma is the most common and lethal malignant intracranial tumor. Long noncoding RNAs (lncRNAs) have been identified as pivotal regulators in the tumorigenesis of glioma. However, the role of lncRNA urothelial carcinoma-associated 1 (UCA1) in glioma genesis is still unknown. The purpose of this study was to investigate the underlying function of UCA1 on glioma genesis. The results demonstrated that UCA1 was upregulated in glioma tissue and indicated a poor prognosis. UCA1 knockdown induced by si-UCA1 significantly suppressed the proliferative, migrative, and invasive activities of glioma cell lines (U87 and U251). Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-122 at the 3'-UTR. Functional experiments revealed that UCA1 acted as an miR-122 "sponge" to modulate glioma cell proliferation, migration, and invasion via downregulation of miR-122. Overall, the present study demonstrated that lncRNA UCA1 acts as an endogenous sponge of miR-122 to promote glioma cell proliferation, migration, and invasion, which provides a novel insight and therapeutic target in the tumorigenesis of glioma.

The DEAD-Box RNA Helicase DDX3 Interacts with m6A RNA Demethylase ALKBH5

DDX3 is a member of the family of DEAD-box RNA helicases. DDX3 is a multifaceted helicase and plays essential roles in key biological processes such as cell cycle, stress response, apoptosis, and RNA metabolism. In this study, we found that DDX3 interacted with ALKBH5, an m⁶A RNA demethylase. The ATP domain of DDX3 and DSBH domain of ALKBH5 were indispensable to their interaction with each other. Furthermore, DDX3 could modulate the demethylation of mRNAs. We also showed that DDX3 regulated the methylation status of microRNAs and there was an interaction between DDX3 and AGO2. The dynamics of m⁶A RNA modification is still a field demanding further investigation, and here, we add a link by showing that RNA demethylation can be regulated by proteins such as DDX3.

Transglutaminase 2 Inhibition Reverses Mesenchymal Transdifferentiation of Glioma Stem Cells by Regulating C/EBPβ Signaling

Necrosis is a hallmark of glioblastoma (GBM) and is responsible for poor prognosis and resistance to conventional therapies. However, the molecular mechanisms underlying necrotic microenvironment-induced malignancy of GBM have not been elucidated. Here, we report that transglutaminase 2 (TGM2) is upregulated in the perinecrotic region of GBM and triggered mesenchymal (MES) transdifferentiation of glioma stem cells (GSC) by regulating master transcription factors (TF), such as C/EBPβ, TAZ, and STAT3. TGM2 expression was induced by macrophages/microglia-derived cytokines via NF-κB activation and further degraded DNA damage-inducible transcript 3 (GADD153) to induce C/EBPβ expression, resulting in expression of the MES transcriptome. Downregulation of TGM2 decreased sphere-forming ability, tumor size, and radioresistance and survival in a xenograft mouse model through a loss of the MES signature. A TGM2-specific inhibitor GK921 blocked MES transdifferentiation and showed significant therapeutic efficacy in mouse models of GSC. Moreover, TGM2 expression was significantly increased in recurrent MES patients and inversely correlated with patient prognosis. Collectively, our results indicate that TGM2 is a key molecular switch of necrosis-induced MES transdifferentiation and an important therapeutic target for MES GBM. Cancer Res; 77(18); 4973-84. ©2017 AACR.

Ivermectin - Old Drug, New Tricks?

Ivermectin is one of the most important drugs in veterinary and human medicine for the control of parasitic infection and was the joint focus of the 2015 Nobel Prize in Physiology or Medicine, some 35 years after its remarkable discovery. Although best described for its activity on glutamate-gated chloride channels in parasitic nematodes, understanding of its mode of action remains incomplete. In the field of veterinary medicine, resistance to ivermectin is now widespread, but the mechanisms underlying resistance are unresolved. Here we discuss the history of this versatile drug and its use in global health. Based on recent studies in a variety of systems, we question whether ivermectin could have additional modes of action on parasitic nematodes.

Ligand-gated ion channels, particularly glutamate-gated chloride channels, are well characterised as the targets of IVM in nematodes and insects.

Nematode genomes are helping to cast light on the diversity of ion-channel subunits in different parasite species of human and veterinary importance.

Resistance to IVM is an increasing problem in the control of parasitic nematodes, and resolving the mechanisms is an important research priority.

Recent studies in other biological systems suggest that IVM can affect a number of additional pathways.

IVM may have novel applications in the treatment and control of important human diseases.