Autophagic degradation of SQSTM1 inhibits ovarian cancer motility by decreasing DICER1 and AGO2 to induce MIRLET7A-3P

The emerging roles of miRNA-mediated autophagy in ovarian cancer

Ovarian cancer is one of the common tumors of the female reproductive organs. It has a high mortality rate, is highly heterogeneous, and early detection and primary prevention are very complex. Autophagy is a cellular process in which cytoplasmic substrates are targeted for degradation in lysosomes through membrane structures called autophagosomes. The periodic elimination of damaged, aged, and redundant cellular molecules or organelles through the sequential translation between amino acids and proteins by two biological processes, protein synthesis, and autophagic protein degradation, helps maintain cellular homeostasis. A growing number of studies have found that autophagy plays a key regulatory role in ovarian cancer. Interestingly, microRNAs regulate gene expression at the posttranscriptional level and thus can regulate the development and progression of ovarian cancer through the regulation of autophagy in ovarian cancer. Certain miRNAs have recently emerged as important regulators of autophagy-related gene expression in cancer cells. Moreover, miRNA analysis studies have now identified a sea of aberrantly expressed miRNAs in ovarian cancer tissues that can affect autophagy in ovarian cancer cells. In addition, miRNAs in plasma and stromal cells in tumor patients can affect the expression of autophagy-related genes and can be used as biomarkers of ovarian cancer progression. This review focuses on the potential significance of miRNA-regulated autophagy in the diagnosis and treatment of ovarian cancer.

Interactions Between Extracellular Vesicles and Autophagy in Neuroimmune Disorders

Neuroimmune disorders, such as multiple sclerosis, neuromyelitis optica spectrum disorder, myasthenia gravis, and Guillain-Barré syndrome, are characterized by the dysfunction of both the immune system and the nervous system. Increasing evidence suggests that extracellular vesicles and autophagy are closely associated with the pathogenesis of these disorders. In this review, we summarize the current understanding of the interactions between extracellular vesicles and autophagy in neuroimmune disorders and discuss their potential diagnostic and therapeutic applications. Here we highlight the need for further research to fully understand the mechanisms underlying these disorders, and to develop new diagnostic and therapeutic strategies.

Bufalin-loaded vitamin E succinate-grafted chitosan oligosaccharide/RGD-conjugated TPGS mixed micelles inhibit intraperitoneal metastasis of ovarian cancer

Background

Intraperitoneal metastasis is one of the major causes of the high mortality rate of ovarian cancer. Bufalin (BU) is an effective component of the traditional Chinese medicine Chansu that exerts antitumor effects, including metastasis inhibition. In our previous studies, we found that BU inhibited the migration and invasion of ovarian cancer cells. However, the application of BU is limited due to its insolubility, toxicity and imprecise targeting. The aim of this study was to use vitamin E succinate (VES)-grafted chitosan oligosaccharide (CSO)/arginine-glycine-aspartic acid peptide (RGD)-conjugated d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) mixed micelles (VeC/T-RGD MMs) to deliver BU to ovarian cancer cells to inhibit intraperitoneal metastasis. Moreover, the toxicity of BU was reduced by coating it with the mixed micelles to increase its biocompatibility for practical applications.

Results

The BU-loaded VeC/T-RGD MMs (BU@MMs) had an average diameter of 161 ± 1.4 nm, a zeta potential of 4.49 ± 1.54 mV and a loading efficiency of 2.54%. The results showed that these micelles inhibited cell proliferation, induced apoptosis, and reduced the migration and invasion of A2780 and SKOV3 cells. Further studies indicated that BU@MMs enhanced the levels of e-cadherin and decreased the expression levels of N-cadherin, vimentin and Snail in vitro. In addition, the mixed micelles effectively enhanced the anticancer effect and inhibited intraperitoneal metastasis in intraperitoneal metastatic models. The BU@MMs exhibited fewer toxic side effects than BU, indicating better biocompatibility and biosafety for in vivo applications.

Conclusions

Our studies show that BU@MMs are a potential multifunctional nano-drug delivery system that can effectively inhibit the intraperitoneal metastasis of ovarian cancer.

VANGL2 inhibits antiviral IFN-I signaling by targeting TBK1 for autophagic degradation

Stringent control of type I interferon (IFN-I) signaling is critical to potent innate immune responses against viral infection, yet the underlying molecular mechanisms are still elusive. Here, we found that Van Gogh-like 2 (VANGL2) acts as an IFN-inducible negative feedback regulator to suppress IFN-I signaling during vesicular stomatitis virus (VSV) infection. Mechanistically, VANGL2 interacted with TBK1 and promoted the selective autophagic degradation of TBK1 via K48-linked polyubiquitination at Lys372 by the E3 ligase TRIP, which serves as a recognition signal for the cargo receptor OPTN. Furthermore, myeloid-specific deletion of VANGL2 in mice showed enhanced IFN-I production against VSV infection and improved survival. In general, these findings revealed a negative feedback loop of IFN-I signaling through the VANGL2-TRIP-TBK1-OPTN axis and highlighted the cross-talk between IFN-I and autophagy in preventing viral infection. VANGL2 could be a potential clinical therapeutic target for viral infectious diseases, including COVID-19.

Roles of non-coding RNAs in cell death pathways involved in the treatment of resistance and recurrence of cancer

Considering the burden of cancer, a number of methods have been applied to control or stop it. However, because of drug resistance or cancer recurrence, these treatments usually face failure. Combination of modulation of expression of non-coding RNAs (ncRNAs) with other treatments can increase treatment-sensitivity of tumors but these approaches still face some challenges. Gathering information in this field is a prerequisite to find more efficient cures for cancer. Cancer cells use ncRNAs to enhance uncontrolled proliferation originated from inactivation of cell death routs. In this review article, the main routes of cell death and involved ncRNAs in these routes are discussed. Moreover, extant information in the role of different ncRNAs on cell death pathways involved in the treatment resistance and cancer recurrence is summarized.

Autophagy, innate immunity, and cardiac disease

Autophagy is an evolutionarily conserved mechanism of cell adaptation to metabolic and environmental stress. It mediates the disposal of protein aggregates and dysfunctional organelles, although non-conventional features have recently emerged to broadly extend the pathophysiological relevance of autophagy. In baseline conditions, basal autophagy critically regulates cardiac homeostasis to preserve structural and functional integrity and protect against cell damage and genomic instability occurring with aging. Moreover, autophagy is stimulated by multiple cardiac injuries and contributes to mechanisms of response and remodeling following ischemia, pressure overload, and metabolic stress. Besides cardiac cells, autophagy orchestrates the maturation of neutrophils and other immune cells, influencing their function. In this review, we will discuss the evidence supporting the role of autophagy in cardiac homeostasis, aging, and cardioimmunological response to cardiac injury. Finally, we highlight possible translational perspectives of modulating autophagy for therapeutic purposes to improve the care of patients with acute and chronic cardiac disease.

Non-apoptotic cell death in ovarian cancer: Treatment, resistance and prognosis

Ovarian cancer is mostly diagnosed at an advanced stage due to the absence of effective screening methods and specific symptoms. Repeated chemotherapy resistance and recurrence before PARPi are used as maintenance therapies, lead to low survival rates and poor prognosis. Apoptotic cell death plays a crucial role in ovarian cancer, which is proved by current researches. With the ongoing development of targeted therapy, non-apoptotic cell death has shown substantial potential in tumor prevention and treatment, including autophagy, ferroptosis, necroptosis, immunogenic cell death, pyroptosis, alkaliptosis, and other modes of cell death. We systematically reviewed the research progress on the role of non-apoptotic cell death in the onset, development, and outcome of ovarian cancer. This review provides a more theoretical basis for exploring therapeutic targets, reversing drug resistance in refractory ovarian cancer, and establishing risk prediction models that help realize the clinical transformation of vital drugs.

Exploring the role of non-coding RNAs in autophagy

As a self-degradative mechanism, macroautophagy/autophagy has a role in the maintenance of energy homeostasis during critical periods in the development of cells. It also controls cellular damage through the eradication of damaged proteins and organelles. This process is accomplished by tens of ATG (autophagy-related) proteins. Recent studies have shown the involvement of non-coding RNAs in the regulation of autophagy. These transcripts mostly modulate the expression of ATG genes. Both long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been shown to modulate the autophagy mechanism. Levels of several lncRNAs and miRNAs are altered in this process. In the present review, we discuss the role of lncRNAs and miRNAs in the regulation of autophagy in diverse contexts such as cancer, deep vein thrombosis, spinal cord injury, diabetes and its complications, acute myocardial infarction, osteoarthritis, pre-eclampsia and epilepsy.Abbreviations: AMI: acute myocardial infarction; ATG: autophagy-related; lncRNA: long non-coding RNA; miRNA: microRNA.

Non-canonical features of microRNAs: paradigms emerging from cardiovascular disease

Research showing that microRNAs (miRNAs) are versatile regulators of gene expression has instigated tremendous interest in cardiovascular research. The overwhelming majority of studies are predicated on the dogmatic notion that miRNAs regulate the expression of specific target mRNAs by inhibiting mRNA translation or promoting mRNA decay in the RNA-induced silencing complex (RISC). These efforts mostly identified and dissected contributions of multiple regulatory networks of miRNA-target mRNAs to cardiovascular pathogenesis. However, evidence from studies in the past decade indicates that miRNAs also operate beyond this canonical paradigm, featuring non-conventional regulatory functions and cellular localizations that have a pathophysiological role in cardiovascular disease. In this Review, we highlight the functional relevance of atypical miRNA biogenesis and localization as well as RISC heterogeneity. Moreover, we delineate remarkable non-canonical examples of miRNA functionality, including direct interactions with proteins beyond the Argonaute family and their role in transcriptional regulation in the nucleus and in mitochondria. We scrutinize the relevance of non-conventional biogenesis and non-canonical functions of miRNAs in cardiovascular homeostasis and pathology, and contextualize how uncovering these non-conventional properties can expand the scope of translational research in the cardiovascular field and beyond.

The Metabolism Reprogramming of microRNA Let-7-Mediated Glycolysis Contributes to Autophagy and Tumor Progression

Cancer is usually a result of abnormal glucose uptake and imbalanced nutrient metabolization. The dysregulation of glucose metabolism, which controls the processes of glycolysis, gives rise to various physiological defects. Autophagy is one of the metabolic-related cellular functions and involves not only energy regeneration but also tumorigenesis. The dysregulation of autophagy impacts on the imbalance of metabolic homeostasis and leads to a variety of disorders. In particular, the microRNA (miRNA) Let-7 has been identified as related to glycolysis procedures such as tissue repair, stem cell-derived cardiomyocytes, and tumoral metastasis. In many cancers, the expression of glycolysis-related enzymes is correlated with Let-7, in which multiple enzymes are related to the regulation of the autophagy process. However, much recent research has not comprehensively investigated how Let-7 participates in glycolytic reprogramming or its links to autophagic regulations, mainly in tumor progression. Through an integrated literature review and omics-related profiling correlation, this review provides the possible linkage of the Let-7 network between glycolysis and autophagy, and its role in tumor progression.

Fasudil prevents neomycin-induced hair cell damage by inhibiting autophagy through the miR-489/NDP52 signaling pathway in HEI-OC1 cells

Hearing loss is a common sensory disorder that is mainly caused by the loss of hair cells (HCs). Drug-induced deafness, for which there is currently no effective treatment, is mainly caused by the inappropriate use of aminoglycoside antibiotics. Fasudil (Fas), a novel isoquinoline sulfonamide derivative, has exhibited antioxidant abilities in a number of previous studies. The aim of the present study was to investigate the potential effects of Fas against neomycin (Neo)-induced hair cell damage and elucidate the underlying mechanism. Flow cytometry and western blot analysis were used to detect the effects of Fas on cell apoptosis and to determine the expression levels of autophagy-related proteins, LC3B and Beclin 1, induced by Neo. Mitochondrial membrane potential and reactive oxygen species (ROS) levels were detected using fluorescent probes. The effect of Fas on Neo-induced hair cell injury marker, GFP-LC3B, was also examined using the immunofluorescence technique. Fas was found to inhibit Neo-induced mitochondrial autophagy and mitochondrial membrane potential decline, in addition to reducing ROS levels and cell apoptosis caused by Neo treatment. However, Fas failed to inhibit the Neo-induced these above changes in cells with NDP52 overexpression. The putative binding sites of microRNA (miR)-489 on the 3'-untranslated region of nuclear dot protein 52 (NDP52) were predicted using the TargetScan 7.0 online tool, and this association was further verified using a dual-luciferase reporter assay. Moreover, the expression of miR-489 negatively regulated the expression of NDP52. Fas and miR-489 mimic inhibited the Neo-induced mitochondrial autophagy and mitochondrial membrane potential decline, in addition to reducing ROS levels and cell apoptosis. Knockdown of miR-489 expression using a miR-489 inhibitor blocked the inhibitory effects of Fas on the mitochondrial membrane potential, cell apoptosis and ROS production. Therefore, Fas may upregulate the expression of miR-489 to negatively regulate the expression of NDP52 at the post-transcriptional level, which in turn inhibits the activation of mitophagy and cell injury induced by Neo. Thus, Fas may act as a novel therapeutic option in the clinical treatment of hearing loss in the future.

Lnc-MEG3 inhibits invasion, migration, and epithelial- mesenchymal transition of nasopharyngeal carcinoma cells by regulating sequestosome 1

BACKGROUND

Long non-coding RNAs regulate malignant behaviors of nasopharyngeal carcinoma (NPC). We aim to investigate the roles and mechanisms of long non-coding RNA maternally expressed gene 3 (lnc-MEG3) in NPC.

METHODS

The expression levels of lnc-MEG3 and sequestosome 1 (SQSTM1) in NPC tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell invasion and migration abilities were evaluated using transwell and wound healing assays, respectively.

RESULTS

Downregulated lnc-MEG3 expression and upregulated SQSTM1 expression were found in NPC tissues and cells. Overexpression of lnc-MEG3 inhibited invasion, migration, and epithelial-mesenchymal transition in NPC cells. Overexpression of lnc-MEG3 reduced the expression level of SQSTM1, and SQSTM1 expression was inversely correlated with lnc-MEG3 level in NPC tissues. Besides, overexpression of SQSTM1 reversed the effects of lnc-MEG3 overexpression. Moreover, knockdown of lnc-MEG3 enhanced NPC progression while its effects were eased by SQSTM1 silence.

CONCLUSION

Lnc-MEG3 inhibits malignant behaviors by regulating SQSTM1 expression. It may serve as a therapeutic target to treat NPC.

Systematic analysis of the relationship between ovarian cancer prognosis and alternative splicing

Background

Ovarian cancer(OC) is the gynecological tumor with the highest mortality rate, effective biomarkers are of great significance in improving its prognosis. In recent years, there have been many studies on alternative splicing (AS) events, and the role of AS events in tumor has become a focus of attention.

Methods

Data were downloaded from the TCGA database and Univariate Cox regression analysis was performed to determine AS events associated with OC prognosis.Eight prognostic models of OC were constructed in R package, and the accuracy of the models were evaluated by the time-dependent receiver operating characteristic (ROC) curves.Eight types of survival curves were drawn to evaluate the differences between the high and low risk groups.Independent prognostic factors of OC were analyzed by single factor independent analysis and multi-factor independent prognostic analysis.Again, Univariate Cox regression analysis was used to analyze the relationship between splicing factors(SF) and AS events, and Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis were performed on OS-related SFs to understand the pathways.

Results

Univariate Cox regression analysis showed that among the 15,278 genes, there were 31,286 overall survival (OS) related AS events, among which 1524 AS events were significantly correlated with OS. The area under the time-dependent receiver operating characteristic curve (AUC) of AT and ME were the largest and the RI was the smallest,which were 0.757 and 0.68 respectively. The constructed models have good value for the prognosis assessment of OC patients. Among the eight survival curves, AP was the most significant difference between the high and low risk groups, with a P value of 1.61e − 1.The results of single factor independent analysis and multi-factor independent prognostic analysis showed that risk score calculated by the model and age could be used as independent risk factors.According to univariate COX regression analysis,109 SFs were correlated with AS events and adjusted in two ways: positive and negative.

Conclusions

SFs and AS events can directly or indirectly affect the prognosis of OC patients. It is very important to find effective prognostic markers to improve the survival rate of OC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00866-1.

A prognosis-predictive nomogram of ovarian cancer with two immune-related genes: CDC20B and PNPLA5

Ovarian carcinoma (OV) is one of the most lethal gynecological malignancies globally, and the overall 5-year survival rate of OV was 47% in 2018 according to American data. To increase the survival rate of patients with OV, many researchers have sought to identify biomarkers that act as both prognosis-predictive markers and therapy targets. However, most of these have not been suitable for clinical application. The present study aimed at constructing a predictive prognostic nomogram of OV using the genes identified by combining The Cancer Genome Atlas (TCGA) dataset for OV with the immune score calculated by the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data algorithm. Firstly, the algorithm was used to calculate the immune score of patients with OV in the TCGA-OV dataset. Secondly, differentially expressed genes (DEGs) between low and high immune score tissues were identified, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed to predict the functions of these DEGs. Thirdly, univariate, multivariate and Lasso Cox's regression analyses were carried out step by step, and six prognosis-related DEGs were identified. Then, Kaplan-Myer survival curves were generated for these genes and validated by comparing their expression levels to further narrow the range of DEGs and to calculate the risk score. Two genes were identified, cell division cycle 20B and patatin-like phospholipase domain containing 5, which were both shown to have higher expression levels in OV tissues and to be significantly associated with the prognosis of OV. Next, a nomogram was created using these two genes and age, and using the receiver operating characteristic (ROC) curve and calibration curve, the effectiveness of the nomogram was validated. Finally, an external validation was conducted for this nomogram. The ROC showed that the areas under the curve (AUCs) of the 3- and 5-year overall survival predictions for the nomogram were 0.678 and 0.62, respectively. Moreover, the ROC of the external validation model showed that the AUCs of the 3- and 5-year were 0.699 and 0.643, respectively, demonstrating the effectiveness of the generated nomogram. In conclusion, the present study has identified two immune-related genes as biomarkers that reliably predict overall survival in OV. These biomarkers might also be potential molecular targets of immune therapy to treat patients with OV.

Sequestosome 1 (p62) accumulation in breast cancer cells suppresses progesterone receptor expression via argonaute 2

Sequestosome 1 (p62) is a multifunctional adapter protein involved in various physiological functions, such as selective autophagy and oxidative stress response. Hence, aberrant expression and defective regulation of p62 are thought to lead to the onset of various diseases, including cancer. The expression of p62 has been shown to be increased in breast cancer tissues, and is correlated with a poor prognosis. However, the role of p62 in the breast cancer pathophysiology is still unclear. Here, we aimed to analyze the effect of changes in p62 expression on breast cancer cell lines. DNA microarray analysis revealed that the expression of progesterone receptor (PR), which is one of the indices for the classification of breast cancer subtypes, was markedly suppressed by forced expression of p62. The protein expression of PR was also decreased by forced expression of p62, but increased by knockdown of p62. Moreover, we found that p62 knockdown induced the protein expression of argonaute 2 (AGO2). Luciferase reporter assay results showed that the gene expression of PR was promoted by AGO2. Furthermore, results revealed that overexpression of AGO2 partially rescued the decrease in PR expression induced by forced expression of p62. Collectively, our findings indicated that p62 accumulation suppressed the expression of AGO2, which in turn decreased the expression of PR, suggesting that p62 may serve as a marker of aggressive breast cancer and poor prognosis. Moreover, the p62-AGO2-PR axis was identified as a crucial signaling cascade in breast cancer progression.

From the Argonauts Mythological Sailors to the Argonautes RNA-Silencing Navigators: Their Emerging Roles in Human-Cell Pathologies

Regulation of gene expression has emerged as a fundamental element of transcript homeostasis. Key effectors in this process are the Argonautes (AGOs), highly specialized RNA-binding proteins (RBPs) that form complexes, such as the RNA-Induced Silencing Complex (RISC). AGOs dictate post-transcriptional gene-silencing by directly loading small RNAs and repressing their mRNA targets through small RNA-sequence complementarity. The four human highly-conserved family-members (AGO1, AGO2, AGO3, and AGO4) demonstrate multi-faceted and versatile roles in transcriptome’s stability, plasticity, and functionality. The post-translational modifications of AGOs in critical amino acid residues, the nucleotide polymorphisms and mutations, and the deregulation of expression and interactions are tightly associated with aberrant activities, which are observed in a wide spectrum of pathologies. Through constantly accumulating information, the AGOs’ fundamental engagement in multiple human diseases has recently emerged. The present review examines new insights into AGO-driven pathology and AGO-deregulation patterns in a variety of diseases such as in viral infections and propagations, autoimmune diseases, cancers, metabolic deficiencies, neuronal disorders, and human infertility. Altogether, AGO seems to be a crucial contributor to pathogenesis and its targeting may serve as a novel and powerful therapeutic tool for the successful management of diverse human diseases in the clinic.