MiR-409-3p Inhibits Cell Proliferation and Invasion of Osteosarcoma by Targeting Zinc-Finger E-Box-Binding Homeobox-1

MicroRNA-409: Molecular functions and clinical applications in cancer

Late diagnosis is one of the main reasons for high mortality rates in cancer patients. Therefore, investigating the molecular mechanisms involved in tumor progression can improve the cancer diagnosis in the early stages of the tumor progression. MicroRNAs (miRNAs) have important roles in regulation of cell growth, proliferation, metabolism, and migration. Since, deregulation of miR-409 has been reported in a wide range of cancers, in the present review, we investigated the molecular mechanisms of miR-409 during tumor progression and invasion. It has been shown that miR-409 functions as a tumor suppressor in different tumor types. MiR-409 can reduce tumor cell proliferation, growth, and migration by regulation of signaling pathways, cellular metabolism, transcription factors, and cellular adhesion. This review can be an effective step in introducing miR-409 as a non-invasive marker in cancer patients.

Investigating the molecular mechanisms of microRNA‑409‑3p in tumor progression: Towards targeted therapeutics (Review)

MicroRNAs (miRNAs) are a group of non‑coding RNAs that exert master regulatory functions in post‑-transcriptional gene expression. Accumulating evidence shows that miRNAs can either promote or suppress tumorigenesis by regulating different target genes or pathways and may be involved in the occurrence of carcinoma. miR‑409‑3p is dysregulated in a variety of malignant cancers. It plays a fundamental role in numerous cellular biological processes, such as cell proliferation, apoptosis, migration, invasion, autophagy, angiogenesis and glycolysis. In addition, studies have shown that miR‑409‑3p is expected to become a non‑invasive biomarker. Identifying the molecular mechanisms underlying miR‑409‑3p‑mediated tumor progression will help investigate miR‑409‑3p‑based targeted therapy for human cancers. The present review comprehensively summarized the recently published literature on miR‑409‑3p, with a focus on the regulation and function of miR‑409‑3p in various types of cancer, and discussed the clinical implications of miR‑409‑3p, providing new insight for the diagnosis and treatment of cancers.

Hsa-miR-409-3p regulates endothelial progenitor senescence via PP2A-P38 and is a potential ageing marker in humans

We explored the roles of hsa-microRNA (miR)-409-3p in senescence and signalling mechanism of human endothelial progenitor cells (EPCs). Hsa-miR-409-3p was found upregulated in senescent EPCs. Overexpression of miRNA mimics in young EPCs inhibited angiogenesis. In senescent EPCs, compared to young EPCs, protein phosphatase 2A (PP2A) was downregulated, with activation of p38/JNK by phosphorylation. Young EPCs treated with siPP2A caused inhibited angiogenesis with activation of p38/JNK, similar to findings in senescent EPCs. Time series analysis showed, in young EPCs treated with hsa-miR-409-3p mimics, PP2A was steadily downregulated for 72 h, while p38/JNK was activated with a peak at 48 hours. The inhibited angiogenesis of young EPCs after miRNA-409-3p mimics treatment was reversed by the p38 inhibitor. The effect of hsa-miR-409-3p on PP2A signalling was attenuated by exogenous VEGF. Analysis of human peripheral blood mononuclear cells (PBMCs) obtained from healthy people revealed hsa-miR-409-3p expression was higher in those older than 65 years, compared to those younger than 30 years, regardless of gender. In summary, hsa-miR-409-3p was upregulated in senescent EPCs and acted as a negative modulator of angiogenesis via targeting protein phosphatase 2 catalytic subunit alpha (PPP2CA) gene and regulating PP2A/p38 signalling. Data from human PBMCs suggested hsa-miR-409-3p a potential biomarker for human ageing.

The Relationship between Serum miRNAs and Early Mortality in Multiple Myeloma Patients Treated with Bortezomib-Based Regimens

Multiple myeloma (MM) is a hematological malignancy characterized by the clonal proliferation of plasma cells in the bone marrow (BM) microenvironment. Despite the progress made in treatment, some MM patients still die within the first year of diagnosis. Numerous studies investigating microRNA (miRNA) expression patterns suggest they may be good prognostic markers. The primary aim of this study was to analyze the expression of selected miRNAs in the serum of MM patients who were later treated with bortezomib-based regimens, and to determine their potential to predict early mortality. The study was conducted in 70 prospectively recruited patients with newly diagnosed MM admitted to the Department of Hematology of the Copernicus Memorial Hospital, Lodz (Poland) between 2017 and 2021. Among them, 17 patients experienced death within 12 months of diagnosis. The expression of 31 selected miRNAs was determined using a miRCURY LNA miRNA Custom PCR Panel. The obtained clinical data included patient characteristics on diagnosis, treatment regimen, response to treatment, and follow-up. Differential expression analysis found two miRNAs to be significantly downregulated in the early mortality group: hsa-miR-328-3p (fold change-FC: 0.72, p = 0.0342) and hsa-miR-409-3p (FC: 0.49, p = 0.0357). Univariate and multivariate logistic regression analyses were performed to assess the early mortality rate. The final model consisted of hsa-miR-409-3p, hsa-miR-328-3p, age, and R-ISS 3. It yielded an area under the curve (AUC) of 0.863 (95%CI: 0.761-0.965) with 88.2% sensitivity and 77.5% specificity. Further external validation of our model is needed to confirm its clinical value.

Knockdown circTRIM28 enhances tamoxifen sensitivity via the miR-409-3p/HMGA2 axis in breast cancer

BACKGROUND

Tamoxifen (TAM) is a frequently-used treatment for breast cancer (BC). But the TAM resistance seriously affects the patient therapeutic effect. Previous research indicated that circular RNAs (circRNAs) might participate in the regulatory processes of BC. Here, we discovered the parts of circular RNA tripartite motif-containing 28 (circTRIM28) in BC.

METHODS

CircTRIM28, microRNA-409-3p (miR-409-3p), and high mobility group AT-hook 2 (HMGA2) levels were perceived by qRT-PCR and western blot. Moreover, the biological functions of the cells were examined. Furthermore, dual-luciferase report was employed to reconnoiter the targeted relationship between miR-409-3p and circTRIM28 or HMGA2.

RESULTS

CircTRIM28 and HMGA2 were augmented, and the miR-409-3p was repressed in BC. Silencing circTRIM28 enhanced tamoxifen sensitivity and cell apoptosis, whereas hampered cell development in BC cells. In mechanism, circTRIM28 could sponge miR-409-3p to increase HMGA2. In addition, silencing circTRIM28 impeded tumor growth.

CONCLUSION

CircTRIM28 facilitated the BC via miR-409-3p/HMGA2.

MicroRNA-409-5p inhibits cell proliferation, and induces G2/M phase arrest and apoptosis by targeting DLGAP5 in ovarian cancer cells

MicroRNA (miRNA/miR)-409-5p has been reported to be implicated in prostate and breast cancers; however, its functional role in ovarian cancer (OC) remains unclear. Therefore the aim of the present study was to investigate the clinical significance and biological function of miR-409-5p in OC. Here, reverse transcription-quantitative PCR analysis was performed to detect miR-409-5p expression in OC tissues and cell lines. The association between miR-409-5p expression and the clinicopathological characteristics of patients with OC was assessed using the Fisher's exact test. Furthermore, the Cell Counting Kit-8 assay was performed to assess cell proliferation. Cell cycle distribution and apoptosis were evaluated via flow cytometric analysis, and the target gene of miR-409-5p was validated via the dual-luciferase reporter assay. The results demonstrated that miR-409-5p expression was significantly downregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. In addition, low miR-409-5p expression was significantly associated with tumor size (P=0.044) and the International Federation of Gynecology and Obstetrics staging system (P=0.005). Notably, overexpression of miR-409-5p suppressed cell proliferation, and induced G₂/M phase arrest and apoptosis of OC cells. Mechanistically, discs large-associated protein 5 (DLGAP5) was identified as a novel target of miR-409-5p, which was negatively regulated by miR-409-5p. DLGAP5 expression was significantly upregulated in OC tissues and cell lines compared with adjacent normal tissues and epithelial cells, respectively. Furthermore, overexpression of DLGAP5 reversed the effects of miR-409-5p on SKOV-3 cell proliferation, and G₂/M phase and apoptosis. Taken together, these results suggest that miR-409-5p acts as a tumor suppressor in OC by modulating DLGAP5 expression.

Circulating Nucleic Acids as Novel Biomarkers for Pancreatic Ductal Adenocarcinoma

Despite considerable advancements in the clinical management of PDAC it remains a significant cause of mortality. PDAC is often diagnosed at advanced stages due to vague symptoms associated with early-stage disease and a lack of reliable diagnostic biomarkers. Late diagnosis results in a high proportion of cases being ineligible for surgical resection, the only potentially curative therapy for PDAC. Furthermore, a lack of prognostic biomarkers impedes clinician's ability to properly assess the efficacy of therapeutic interventions. Advances in our ability to detect circulating nucleic acids allows for the advent of novel biomarkers for PDAC. Tumor derived circulating and exosomal nucleic acids allow for the detection of PDAC-specific mutations through a non-invasive blood sample. Such biomarkers could expand upon the currently limited repertoire of tests available. This review outlines recent developments in the use of molecular techniques for the detection of these nucleic acids and their potential roles, alongside current techniques, in the diagnosis, prognosis and therapeutic governance of PDAC.

Long noncoding RNA CBR3-AS1 mediates tumorigenesis and radiosensitivity of non-small cell lung cancer through redox and DNA repair by CBR3-AS1 /miR-409-3p/SOD1 axis

The long noncoding RNA CBR3-AS1 has important functions in various cancers. However, the biological functions of CBR3-AS1 in non-small cell lung cancer (NSCLC) remain unclear. This study aimed to investigate the roles and molecular mechanisms of CBR3-AS1 in NSCLC tumorigenesis and radiosensitivity. Here, we demonstrate CBR3-AS1 overexpression in NSCLC tissue compared with adjacent normal tissue. CBR3-AS1 downregulation reduced proliferation, invasion, and migration; inhibited cell cycle progression; and promoted apoptosis of NSCLC cells. CBR3-AS1 also promoted tumor growth in vivo. CBR3-AS1 may regulate the expression and functions of the miR-409-3p target gene SOD1. CBR3-AS1 expression was negatively correlated with radiosensitivity. CBR3-AS1 downregulation decreased post-irradiation SOD1 expression, increased γH2AX formation, raised levels of reactive oxygen species, and promoted apoptosis. Our results suggest that CBR3-AS1 functions as an oncogene through the CBR3-AS1/miR-409-3p/SOD1 pathway, and may represent a new therapeutic target, especially to regulate radiosensitivity in NSCLC.

The clinical significance of microRNA-409 in pancreatic carcinoma and associated tumor cellular functions

In recent years, the increasing incidence of pancreatic carcinoma (PC) patients has become one of the hot issues in the world. microRNAs (miRNAs) can act as oncogenes or tumor suppressor genes and have unpredictable effects on tumors, thus affecting the prognosis and survival of cancer patients. In this paper, we mainly studied the role of microRNA (miR)-409 in PC. The expression levels of miR-409 were analyzed by qRT-PCR. Kaplan-Meier curve and Cox regression were used to analyze the relationship between miR-409 and patient prognosis. The effects of miR-409 on the abilities of proliferation, migration and invasion were detected by CCK-8 and Transwell. The expression levels of miR-409 were down-regulated in PC, compared with normal controls. The prognosis of patients with low miR-409 expression is significantly poor in comparison with those with high expression. The down-regulation of miR-409 was conducive to the proliferation, migration and invasion of PC cells. miR-409 is a tumor suppressor of PC, the clinical significance of miR-409 in pancreatic cancer and related tumor cell function was clarified.

MiR-409-3p targets a MAP4K3-ZEB1-PLGF signaling axis and controls brown adipose tissue angiogenesis and insulin resistance

Endothelial cells (ECs) within the microvasculature of brown adipose tissue (BAT) are important in regulating the plasticity of adipocytes in response to increased metabolic demand by modulating the angiogenic response. However, the mechanism of EC-adipocyte crosstalk during this process is not completely understood. We used RNA sequencing to profile microRNAs derived from BAT ECs of obese mice and identified an anti-angiogenic microRNA, miR-409-3p. MiR-409-3p overexpression inhibited EC angiogenic properties; whereas, its inhibition had the opposite effects. Mechanistic studies revealed that miR-409-3p targets ZEB1 and MAP4K3. Knockdown of ZEB1/MAP4K3 phenocopied the angiogenic effects of miR-409-3p. Adipocytes co-cultured with conditioned media from ECs deficient in miR-409-3p showed increased expression of BAT markers, UCP1 and CIDEA. We identified a pro-angiogenic growth factor, placental growth factor (PLGF), released from ECs in response to miR-409-3p inhibition. Deficiency of ZEB1 or MAP4K3 blocked the release of PLGF from ECs and PLGF stimulation of 3T3-L1 adipocytes increased UCP1 expression in a miR-409-3p dependent manner. MiR-409-3p neutralization improved BAT angiogenesis, glucose and insulin tolerance, and energy expenditure in mice with diet-induced obesity. These findings establish miR-409-3p as a critical regulator of EC-BAT crosstalk by modulating a ZEB1-MAP4K3-PLGF signaling axis, providing new insights for therapeutic intervention in obesity.

CircSCAP aggravates oxidized low-density lipoprotein-induced macrophage injury by upregulating PDE3B via miR-221-5p in atherosclerosis

ABSTRACT

Atherosclerosis (AS) is a major risk factor for cardiovascular disease, in which circular RNAs (circRNAs) play important regulatory roles. This research aimed to explore the biological role of circSCAP (hsa_circ_0001292) in AS development. Real-time PCR or western blot assay was conducted to analyze RNA or protein expression. Cell proliferation and apoptosis were analyzed by CCK-8 assay and flow cytometry. The levels of lipid accumulation-associated indicators and oxidative stress factors were detected using commercial kits. The levels of inflammatory cytokines were examined using enzyme-linked immunosorbent assay (ELISA). Intermolecular interaction was verified via dual-luciferase reporter analysis or RNA pull-down analysis. CircSCAP and phosphodiesterase 3B (PDE3B) levels were elevated, whereas miR-221-5p level was decreased in AS patients and oxidized low-density lipoprotein (ox-LDL)-induced THP-1 cells. CircSCAP absence suppressed lipid deposition, inflammation, and oxidative stress in ox-LDL-induced THP-1 cells. MiR-221-5p was a target of circSCAP, and anti-miR-221-5p largely reversed si-circSCAP-induced effects in ox-LDL-induced THP-1 cells. PDE3B was a target of miR-221-5p, and PDE3B overexpression largely counteracted miR-221-5p accumulation-mediated effects in ox-LDL-induced THP-1 cells. NF-κB signaling pathway was regulated by circSCAP/miR-221-5p/PDE3B axis in ox-LDL-induced THP-1 cells. In conclusion, circSCAP facilitated lipid accumulation, inflammation, and oxidative stress in ox-LDL-induced THP-1 macrophages by regulating miR-221-5p/PDE3B axis.

Oncogenic functions of ZEB1 in pediatric solid cancers: interplays with microRNAs and long noncoding RNAs

The transcription factor Zinc finger E-box binding 1 (ZEB1) displays a range of regulatory activities in cell function and embryonic development, including driving epithelial-mesenchymal transition. Several aspects of ZEB1 function can be regulated by its functional interactions with noncoding RNA types, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Increasing evidence indicates that ZEB1 importantly influences cancer initiation, tumor progression, metastasis, and resistance to treatment. Cancer is the main disease-related cause of death in children and adolescents. Although the role of ZEB1 in pediatric cancer is still poorly understood, emerging findings have shown that it is expressed and regulates childhood solid tumors including osteosarcoma, retinoblastoma, neuroblastoma, and central nervous system tumors. Here, we review the evidence supporting a role for ZEB1, and its interplays with miRNAs and lncRNAs, in pediatric cancers.

Hsa_circ_0054633 mediates apoptosis and insulin secretion in human pancreatic β cells through miR-409-3p/caspase-8 axis

BACKGROUND

CircRNAs are reported to be aberrantly expressed and perform biological functions in diverse processes. This study aimed to investigate the potential involvement of hsa_circ_0054633 in high glucose (HG)‑induced diabetic model and its potential mechanism.

METHODS

The expression of hsa_circ_0054633, miR-409-3p and caspase-8 was detected by real-time PCR and western blotting. Cell viability, apoptosis and the protein levels of apoptosis-related factors were revealed by CCK-8 colorimetry, flow cytometry and western blotting, respectively. Insulin secretion was determined by enzyme-linked immunosorbent assay (ELISA) and the measurement of insulin-related transcription factors. The target association between miR-409-3p and hsa_circ_0054633 or caspase-8 was confirmed by dual-luciferase reporter assays and biotin-based pulldown assay.

RESULTS

Hsa_circ_0054633 was highly expressed and the expression of miR-409-3p was downregulated in serum of DM patients and HG-treated human pancreatic β cell line NES2Y. Further investigation indicated that hsa_circ_0054633 suppression promoted cell proliferation, inhibited apoptosis and facilitated insulin secretion in HG-treated NES2Y cells. Mechanical analysis revealed that hsa_circ_0054633 regulated caspase-8 expression via sponging miR-409-3p. Rescue experiments demonstrated that miR-409-3p knockdown or caspase-8 overexpression reversed the effects of hsa_circ_0054633 in HG-stimulated NES2Y cells.

CONCLUSION

Inhibition of hsa_circ_0054633 protected against HG-induced NES2Y cell apoptosis and impairment of insulin secretion by regulating miR-409-3p/caspase-8 axis.

CircRNA DOCK1 Regulates miR-409-3p/MCL1 Axis to Modulate Proliferation and Apoptosis of Human Brain Vascular Smooth Muscle Cells

Background

Intracranial aneurysm is an abnormal expansion in the intracranial arteries, which is associated with growth and apoptosis of vascular smooth muscle cells. Circular RNAs (circRNAs) have implicated in the progression of intracranial aneurysms. The purpose of this paper is to study the function and mechanism of circRNA dedicator of cytokinesis 1 (circ_DOCK1) in regulating proliferation and apoptosis of human brain vascular smooth muscle cells (HBVSMCs).

Methods

HBVSMCs were exposed to hydrogen peroxide (H₂O₂). Cell proliferation and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and flow cytometry, respectively. Circ_DOCK1, microRNA (miR)-409-3p, and myeloid cell leukemia sequence 1 (MCL1) levels were examined by quantitative reverse transcription polymerase chain reaction or western blotting. The target association was assessed by dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation assays.

Results

Exposure to H₂O₂ decreased proliferation and increased apoptosis of HBVSMCs. Circ_DOCK1 expression was reduced in H₂O₂-treated HBVSMCs. Circ_DOCK1 overexpression rescued H₂O₂-caused reduction of proliferation and PCNA expression and attenuated H₂O₂-induced apoptosis and expression of Bcl-2, Bax, and cleaved PARP. MiR-409-3p was targeted by circ_DOCK1 and upregulated in H₂O₂-treated HBVSMCs. MiR-409-3p upregulation mitigated the role of circ_DOCK1 in proliferation and apoptosis of H₂O₂-treated HBVSMCs. MCL1 was targeted via miR-409-3p and downregulated via H₂O₂ treatment. Circ_DOCK1 overexpression enhanced MCL1 expression via modulating miR-409-3p. MiR-409-3p knockdown weakened H₂O₂-induced proliferation reduction and apoptosis promotion via regulating MCL1.

Conclusion

Circ_DOCK1 overexpression mitigated H₂O₂-caused proliferation inhibition and apoptosis promotion in HBVSMCs by modulating miR-409-3p/MCL1 axis.

The EMT transcription factor ZEB1 blocks osteoblastic differentiation in bone development and osteosarcoma

Osteosarcoma is an often-fatal mesenchyme-derived malignancy in children and young adults. Overexpression of EMT-transcription factors (EMT-TFs) has been associated with poor clinical outcome. Here, we demonstrated that the EMT-TF ZEB1 is able to block osteoblastic differentiation in normal bone development as well as in osteosarcoma cells. Consequently, overexpression of ZEB1 in osteosarcoma characterizes poorly differentiated, highly metastatic subgroups and its depletion induces differentiation of osteosarcoma cells. Overexpression of ZEB1 in osteosarcoma is frequently associated with silencing of the imprinted DLK-DIO3 locus, which encodes for microRNAs targeting ZEB1. Epigenetic reactivation of this locus in osteosarcoma cells reduces ZEB1 expression, induces differentiation, and sensitizes to standard treatment, thus indicating therapeutic options for ZEB1-driven osteosarcomas. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

CircFAT1 facilitates cervical cancer malignant progression by regulating ERK1/2 and p38 MAPK pathway through miR-409-3p/CDK8 axis

Circular RNA FAT atypical cadherin 1 (circFAT1) has been reported to play vital roles in the progression of some cancers. However, the regulatory role and underlying mechanisms of circFAT1 in cervical cancer (CC) remain largely unknown. The expression of circFAT1, microRNA (miR)-409-3p and cyclin-dependent kinase 8 (CDK8) was detected using qRT-PCR and Western blot assays. Cell proliferation, apoptosis, migration and invasion in vitro were investigated using cell counting kit-8, colony formation, flow cytometry, and transwell assays, respectively. Western blot assay was used to determine the activation of ERK1/2 and p38 MAPK pathway. The interaction miR-409-3p and circFAT1 or CDK8 was confirmed by dual-luciferase reporter, pull-down or RIP assays. The effects of circFAT1 in vivo were determined using xenograft models. CircFAT1 was highly expressed in CC, and closely associated with poor prognosis. CircFAT1 knockdown resulted in the suppression of proliferation, migration and invasion, and promotion of apoptosis in CC cells via the inactivation of ERK1/2 and p38 MAPK pathway; also, circFAT1 silencing could inactivate this pathway and repressed CC tumor growth in vivo. Mechanistic analysis showed that circFAT1 directly sponged miR-409-3p and then relieved the repressive effect of miR-409-3p on its target CDK8. Furthermore, miR-409-3p inhibition reversed the effects of circFAT1 silencing on CC cells. Whereas, miR-409-3p overexpression impeded CC cell growth and motility, which was attenuated by CDK8. CircFAT1 promoted CC progression via activating ERK1/2 and p38 MAPK pathway through the miR-409-3p/CDK8 axis, suggesting a promising prognostic biomarker and therapeutic target for CC.

Precision hyperthermia-induced miRNA-409-3p upregulation inhibits migration, invasion, and EMT of gastric cancer cells by targeting KLF17

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) is widely used for clinical treatment of advanced cancers. However, the regulatory mechanism underlying precise hyperthermia treatment in advanced gastric cancer (AGC) remains unclear. MiR-409-3p is reportedly downregulated in a variety of cancers, although its role in regulating treatment of AGC by precise hyperthermia remains unclear. The underlying mechanisms of miRNA-medicated regulation have been investigated using predicted and validated miRNA-gene targets, confirming the role of miRNA in HIPEC; METHODS: We used quantitative real time PCR (qRT-PCR) to detect miR-409-3p expression in gastric cancer (GC), as well as adjacent normal tissues, following exposure to varying temperatures. We detected miR-409-3p targets using dual-luciferase assay, then performed cell apoptosis, western blotting, invasion, and migration assays to detect GC functions; RESULTS: MiR-409-3p was upregulated and downregulated in precise hyperthermia and AGC, respectively. Moreover, miR-409-3p upregulated the Krüppel-like-factor 17 (KLF17), which subsequently inhibited migration, invasiveness, and epithelial-mesenchymal transition (EMT) but promoted apoptosis in GC cells; CONCLUSIONS: Precise hyperthermia upregulated miR-409-3p and KLF17 indirectly, thereby inhibiting invasion, migration, and EMT, and promoting apoptosis of gastric cancer cells.

Altered microRNA Profiles of Extracellular Vesicles Secreted by Endometrial Cells from Women with Recurrent Implantation Failure

Recurrent implantation failure (RIF) is characterized by repeated embryo transfers without pregnancy. To date, the etiology of RIF remains poorly understood. Accumulating evidence indicates a beneficial role of endometrial extracellular vesicles (EVs) during the implantation by delivering signaling molecules to embryos, especially miRNAs. However, whether EVs secreted by RIF patients' endometria have a similar miRNA expression profile of endometrial EVs of fertile women has not been investigated. Therefore, in this study, we compared the miRNA expression profiles between the endometrial EVs of RIF patients (RIF-EVs) and fertile women (FER-EVs). Endometrial tissues from fifteen RIF patients and nine fertile women were collected and digested to cells for culture. Endometrial cells were modulated by estrogen and progesterone to mimic the secretory phase, and the conditioned medium was collected for EV isolation. EVs were determined by western blotting, nanoparticle tracking analysis, and transmission electronic microscopy (TEM). Three pairs of EV samples from two groups were used for miRNA sequencing, and twelve RIF-EV samples and six FER-EV samples were used for validation using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results showed that a total of 11 miRNAs were differently expressed in the RIF-EVs. Besides, four of the differently expressed miRNAs were validated using qRT-PCR. Target genes of the differently expressed miRNAs were predicted, and the functional analysis was performed. Besides, we proved that the most significantly different miRNA, 6131, inhibited the growth and invasion of HTR8/SVneo cells. Our study suggested that the altered miRNAs in the RIF-EVs might be involved in the pathogenesis of RIF.

Potential therapeutic approaches of microRNAs for COVID-19: Challenges and opportunities

The coronavirus disease 2019 (COVID-19) emerges as current outbreak cause by Novel Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2). This infection affects respiratory system and provides uncontrolled systemic inflammatory response as cytokine storm. The main concern about SARS-CoV-2 pandemic is high viral pathogenicity with no specific drugs. MicroRNAs (miRs) as small non-coding RNAs (21–25 ​nt) regulate gene expression. The SARS-CoV-2 encoded-miRs affect human genes that involved in transcription, translation, apoptosis, immune response and inflammation. Also, they alter self-gene regulation and hijacked host miRs that provide protective environment to maintain its latency. On the other hand, Host miRs play critical role in viral gene expression to restrict infection. Over expression/inhibition of miRs might result in cell cycle irregularity, impaired immune response or cancer. In this manner, exact role of each miR should be specified. Mimic encoded-miRs like antagomirs showed successful result in phases of clinical trial prevent from negative effects of viral encoded-miRs. Products of mimic miRs are inexpensive corresponds to synthesis of primer; they are short and nanoscale in size. Although SARS-CoV-2 genome is undergoing evaluation, detection of exact molecular pathogenesis open up opportunities to for vaccine development. Salivaomics can evaluate SARS-CoV-2 genome, transcriptome, proteome and biomarkers like miRs in oral related and cancer disease. In this review, we studied the challenge and opportunities of miRs in therapeutic approach for SARS-CoV-2 infection, then overviewed the role of miRs in saliva droplet during SARS-CoV-2 infection and related cancer.

Circ_0000285 regulates proliferation, migration, invasion and apoptosis of osteosarcoma by miR-409-3p/IGFBP3 axis

Background

Circular RNAs (circRNAs) are important regulators in the pathogenesis of diseases and affects the occurrence and development of diseases. However, the role of circRNAs in osteosarcoma (OS) has not been fully elucidated.

Methods

The expression of circ_0000285, miR-409-3p and insulin-like growth factor binding protein 3 (IGFBP3) was detected using quantitative real-time PCR (qRT-PCR). The protein level of IGFBP3 was measured using western blot. CCK-8 and colony formation assays were used to determine cell proliferation. Flow cytometry was applied to measure cell cycle and cell apoptosis. Transwell assay was used to assess cell invasion and migration. Dual-luciferase reporter assay and RNA Binding Protein Immunoprecipitation (RIP) assay were performed to determine the relationship among circ_0000285, miR-409-3p and IGFBP3. The animal experiments were performed to determine the function of circ_0000285 in vivo.

Results

In this study, we found that the expression of circ_0000285 was significantly increased in OS tissues and cells and was enriched in the cytoplasm. Knockdown of circ_0000285 inhibited OS growth in vitro and in vivo. Moreover, miR-409-3p was a target miRNA of circ_0000285 and miR-409-3p targets to IGFBP3 in OS. Besides, circ_0000285 could promote proliferation, migration, invasion and inhibit apoptosis of osteosarcoma by miR-409-3p/IGFBP3 axis.

Conclusion

In this study, circ_0000285 regulated proliferation, migration, invasion and apoptosis of OS cells by miR-409-3p/IGFBP3 axis, implying that circ_0000285 was a potential target for OS therapy.

Autophagy-mediating microRNAs in cancer chemoresistance

Chemoresistance is a complex phenomenon responsible for failure in response to chemotherapy agents and more than 90% of deaths in cancer patients. MicroRNAs (miRNAs), as a subgroup of non-coding RNAs with lengths between 21 and 25 nucleotides, are involved in various cancer processes like chemoresistance via interacting with their target mRNAs and suppressing their expression. Autophagy is a greatly conserved procedure involving the lysosomal degradation of cytoplasmic contents and organelles to deal with environmental stresses like hypoxia and starvation. Autophagy contributes to response to chemotherapy agents: autophagy can act as a protective mechanism for mediating the resistance in response to chemotherapy or can induce autophagic cell death and mediate the sensitivity to chemotherapy. On the other hand, one of the processes targeted by microRNAs in the regulation of chemoresistance is autophagy. Hence, we studied the literatures on chemoresistance mechanisms, the miRNAs' role in cancer, and the miRNAs' role in chemoresistance by modulating autophagy. Graphical Abstract.

Circ_0000745 Promotes the Progression of Cervical Cancer by Regulating miR-409-3p/ATF1 Axis

Background: Cervical cancer (CC) is a common gynecological malignancy with a high risk of recurrence and death. Circular RNAs play a crucial role in the occurrence and development of tumors. This study aimed to investigate the function and mechanism of circ_0000745 in CC. Methods: The levels of circ_0000745, miR-409-3p, and activating transcription factor 1 (ATF1) were determined by quantitative real-time polymerase chain reaction or western blot assay. Cell proliferation was assessed by colony formation assay. Cell migration and invasion were evaluated by transwell assay. Glycolysis was analyzed by measuring extracellular acidification rate, glucose uptake, and lactate production. Also, the protein levels of glucose transporter 1 and lactate dehydrogenase A were detected using western blot. The relationship among circ_0000745, miR-409-3p, and ATF1 were confirmed by dual-luciferase reporter assay. Moreover, xenograft assay was performed to analyze tumor growth in vivo. Results: Circ_0000745 and ATF1 were upregulated, whereas miR-409-3p was downregulated in CC tissues and cells. Knockdown of circ_0000745 repressed proliferation, migration, invasion, and glycolysis of CC cells. Circ_0000745 regulated CC progression by targeting miR-409-3p. Circ_0000745 modulated ATF1 expression through sponging miR-409-3p. MiR-409-3p hindered CC progression by targeting ATF1. Furthermore, depletion of circ_0000745 impeded tumor growth in vivo. Conclusion: Circ_0000745 promoted the progression of CC through modulating miR-409-3p/ATF1 axis, indicating a promising biomarker for CC therapy.

Differences between Well-Differentiated Neuroendocrine Tumors and Ductal Adenocarcinomas of the Pancreas Assessed by Multi-Omics Profiling

Most pancreatic neuroendocrine tumors (PNETs) are indolent, while pancreatic ductal adenocarcinomas (PDACs) are particularly aggressive. To elucidate the basis for this difference and to establish the biomarkers, by using the deep sequencing, we analyzed somatic variants across coding regions of 409 cancer genes and measured mRNA/miRNA expression in nine PNETs, eight PDACs, and four intestinal neuroendocrine tumors (INETs). There were 153 unique somatic variants considered pathogenic or likely pathogenic, found in 50, 57, and 24 genes in PDACs, PNETs, and INETs, respectively. Ten and 11 genes contained a pathogenic mutation in at least one sample of all tumor types and in PDACs and PNETs, respectively, while 28, 34, and 11 genes were found to be mutated exclusively in PDACs, PNETs, and INETs, respectively. The mRNA and miRNA transcriptomes of PDACs and NETs were distinct: from 54 to 1659 differentially expressed mRNAs and from 117 to 250 differentially expressed miRNAs exhibited high discrimination ability and resulted in models with an area under the receiver operating characteristics curve (AUC-ROC) >0.9 for both miRNA and mRNA. Given the miRNAs high stability, we proposed exploring that class of RNA as new pancreatic tumor biomarkers.

Circ_0001023 Promotes Proliferation and Metastasis of Gastric Cancer Cells Through miR-409-3p/PHF10 Axis

Background

Circular RNAs (circRNAs) have been well documented to regulate the gene expression via sponging microRNA (miRNA) in diverse neoplasms including gastric cancer (GC).

Methods

In the present study, the expressions of circ_0001023, miR-409-3p, and plant homeodomain finger 10 (PHF10) in GC tissues were detected by qRT-PCR. Chi-square test was performed to analyze the associations between circ_0001023 and pathological parameters. Cell Counting Kit-8 assay, colony formation assay, flow cytometry, and transwell assay were adopted to detect the role of circ_0001023/miR-409-3p axis in the proliferation, apoptosis, and migration of GC cells, respectively. The targeting relationship between circ_0001023 and miR-409-3p was investigated by dual-luciferase gene reporter gene assay. Additionally, subcutaneous xenotransplanted tumor model in nude mice was established to detect the function of circ_0001023 on GC growth in vivo.

Results

Compared with adjacent tissues, the expression of circ_0001023 was significantly upregulated and correlated with lymph node invasion and higher T stage of GC patients. It has also been proved that circ_0001023 could target miR-409-3p. Silencing circ_0001023 can impede the proliferation of GC cells and promote apoptosis, while miR-409-3p inhibitors can partially reverse the biological behavior of GC cells mentioned above. Moreover, the expression of circ_0001023 was reversely associated with miR-409-3p expression but positively correlated with PHF10, a downstream oncogene of miR-409-3p.

Conclusion

Collectively, it is concluded that circ_0001023 promotes the progression of GC via regulating miR-409-3p/PHF10 axis.

COVID-19 Virulence in Aged Patients Might Be Impacted by the Host Cellular MicroRNAs Abundance/Profile

The World health organization (WHO) declared Coronavirus disease 2019 (COVID-19) a global pandemic and a severe public health crisis. Drastic measures to combat COVID-19 are warranted due to its contagiousness and higher mortality rates, specifically in the aged patient population. At the current stage, due to the lack of effective treatment strategies for COVID-19 innovative approaches need to be considered. It is well known that host cellular miRNAs can directly target both viral 3'UTR and coding region of the viral genome to induce the antiviral effect. In this study, we did in silico analysis of human miRNAs targeting SARS (4 isolates) and COVID-19 (29 recent isolates from different regions) genome and correlated our findings with aging and underlying conditions. We found 848 common miRNAs targeting the SARS genome and 873 common microRNAs targeting the COVID-19 genome. Out of a total of 848 miRNAs from SARS, only 558 commonly present in all COVID-19 isolates. Interestingly, 315 miRNAs are unique for COVID-19 isolates and 290 miRNAs unique to SARS. We also noted that out of 29 COVID-19 isolates, 19 isolates have identical miRNA targets. The COVID-19 isolates, Netherland (EPI_ISL_422601), Australia (EPI_ISL_413214), and Wuhan (EPI_ISL_403931) showed six, four, and four unique miRNAs targets, respectively. Furthermore, GO, and KEGG pathway analysis showed that COVID-19 targeting human miRNAs involved in various age-related signaling and diseases. Recent studies also suggested that some of the human miRNAs targeting COVID-19 decreased with aging and underlying conditions. GO and KEGG identified impaired signaling pathway may be due to low abundance miRNA which might be one of the contributing factors for the increasing severity and mortality in aged individuals and with other underlying conditions. Further, in vitro and in vivo studies are needed to validate some of these targets and identify potential therapeutic targets.

MicroRNAs and Metastasis

Metastasis, the development of secondary malignant growths at a distance from the primary site of a cancer, is associated with almost 90% of all cancer deaths, and half of all cancer patients present with some form of metastasis at the time of diagnosis. Consequently, there is a clear clinical need for a better understanding of metastasis. The role of miRNAs in the metastatic process is beginning to be explored. However, much is still to be understood. In this review, we present the accumulating evidence for the importance of miRNAs in metastasis as key regulators of this hallmark of cancer.