MiR-20a-5p suppresses tumor proliferation by targeting autophagy-related gene 7 in neuroblastoma

Insights on E1-like enzyme ATG7: functional regulation and relationships with aging-related diseases

Autophagy is a dynamic self-renovation biological process that maintains cell homeostasis and is responsible for the quality control of proteins, organelles, and energy metabolism. The E1-like ubiquitin-activating enzyme autophagy-related gene 7 (ATG7) is a critical factor that initiates classic autophagy reactions by promoting the formation and extension of autophagosome membranes. Recent studies have identified the key functions of ATG7 in regulating the cell cycle, apoptosis, and metabolism associated with the occurrence and development of multiple diseases. This review summarizes how ATG7 is precisely programmed by genetic, transcriptional, and epigenetic modifications in cells and the relationship between ATG7 and aging-related diseases.

Exploring the utility of FTS as a bonafide binding partner for EGFR: A potential drug target for cervical cancer

Establishment of human papilloma virus (HPV) infection and its progression to cervical cancer (CC) requires the participation of epidermal growth factor (EGF) receptor (EGFR) and fused toes homolog (FTS). This review is an attempt to understand the structure-function relationship between FTS and EGFR as a tool for the development of newer CC drugs. Motif analysis was performed using national center for biotechnology information (NCBI), kyoto encyclopedia of genes and genomes (KEGG), simple modular architecture research tool (SMART) and multiple expectation maximizations for motif elicitation (MEME) database. The secondary and tertiary structure prediction of FTS was performed using DISOPRED3 and threading assembly, respectively. A positive correlation was found between the transcript levels of FTS and EGFR. Amino acids responsible for interaction between EGFR and FTS were determined. The nine micro-RNAs (miRNAs) that regulates the expression of FTS were predicted using Network Analyst 3.0 database. hsa-miR-629-5p and hsa-miR-615-3p are identified as significant positive and negative regulators of FTS gene expression. This review opens up new avenues for the development of CC drugs which interfere with the interaction between FTS and EGFR.

Role of non-coding RNAs in neuroblastoma

Neuroblastoma is known as the most prevalent extracranial malignancy in childhood with a neural crest origin. It has been widely accepted that non-coding RNAs (ncRNAs) play important roles in many types of cancer, including glioma and gastrointestinal cancers. They may regulate the cancer gene network. According to recent sequencing and profiling studies, ncRNAs genes are deregulated in human cancers via deletion, amplification, abnormal epigenetic, or transcriptional regulation. Disturbances in the expression of ncRNAs may act either as oncogenes or as anti-tumor suppressor genes, and can lead to the induction of cancer hallmarks. ncRNAs can be secreted from tumor cells inside exosomes, where they can be transferred to other cells to affect their function. However, these topics still need more study to clarify their exact roles, so the present review addresses different roles and functions of ncRNAs in neuroblastoma.

Polycyclic aromatic hydrocarbons exposure was associated with microRNA differential expression and neurotransmitter changes: a cross-sectional study in coal miners

Exposure to polycyclic aromatic hydrocarbons (PAHs) may cause neurobehavioral changes. This study aimed to explore the underlying mechanism of PAH neurotoxicity in coal miners. Urinary PAH metabolites, neurotransmitters, and oxidative stress biomarkers of 652 coal miners were examined. Subjects were divided into high and low-exposure groups based on the median of total urinary PAH metabolites. Differentially expressed miRNAs were screened from 5 samples in the low-exposure group (≤ 4.88 μmol/mol Cr) and 5 samples in the high-exposure group (> 4.88 μmol/mol Cr) using microarray technology, followed by bioinformatics analysis of the potential molecular functions of miRNA target genes. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to validate differentially expressed miRNAs. Restricted cubic splines (RCS) were applied to assess the possible dose-response relationships. Compared to the low PAH exposure group, the high-exposure group had higher levels of 5-hydroxytryptamine (5-HT), epinephrine (E), and acetylcholine (ACh), and lower levels of acetylcholinesterase (AChE). 1-OHP had a dose-response relationship with malondialdehyde (MDA), dopamine (DA), 5-HT, and AChE (P for overall associations < 0.05). There were 19 differentially expressed microRNAs in microarray analysis, significantly enriched in the cell membrane, molecular binding to regulate transcription, and several signaling pathways such as PI3K-Akt. And in the validation stage, miR-885-5p, miR-20a-5p, and let-7i-3p showed differences in the low and high-exposure groups (P < 0.05). Changes in neurotransmitters and microRNA expression levels among the coal miners were associated with PAH exposure. Their biological functions are mainly related to the transcriptional regulation of nervous system diseases or signaling pathways of disorders. These findings provide new insights for future research of PAH neurotoxicity.

MicroRNA panels as diagnostic biomarkers for colorectal cancer: A systematic review and meta-analysis

Background

Circulating microRNAs (miRNA) have emerged as promising diagnostic biomarkers for several diseases, including cancer. However, the diagnostic accuracy of miRNA panels in colorectal cancer (CRC) remains inconsistent and there is still lack of meta-analyses to determine whether miRNA panels can serve as robust biomarkers for CRC diagnosis.

Methods

This study performed a systematic review and meta-analysis to evaluate the clinical utility of miRNA panels as potential biomarkers for the diagnosis of CRC. The investigation systematically searched PubMed, Medline, Web of Science, Cochrane Library, and Google Scholar (21-year span, between 2000 and 2021) to retrieve articles reporting the diagnostic role of miRNA panels in detecting CRC. Diagnostic meta-analysis of miRNA panels used diverse evaluation indicators, including sensitivity, specificity, Positive Likelihood Ratio (PLR), Negative Likelihood Ratio (NLR), Diagnostic Odds Ratio (DOR), and the area under the curve (AUC) values.

Results

Among the 313 articles identified, 20 studies met the inclusion criteria. The pooled estimates of miRNA panels for the diagnosis of CRC were 0.85 (95% CI: 0.84-0.86), 0.79 (95% CI: 0.78-0.80), 4.06 (95% CI: 3.89-4.23), 0.20 (95% CI: 0.19-0.20), 22.50 (95% CI: 20.81-24.32) for sensitivity, specificity, PLR, NLR, and DOR, respectively. Moreover, the summary receiver operating characteristics (SROC) curve revealed an AUC value of 0.915 (95% CI: 0.914-0.916), suggesting an outstanding diagnostic accuracy for overall miRNA panels. Subgroup and meta-regression analyses demonstrated that miRNA panels have the highest diagnostic accuracy within serum samples, rather than in other sample-types - with a sensitivity, specificity, PLR, NLR, DOR, and AUC of 0.87, 0.86, 7.33, 0.13, 55.29, and 0.943, respectively. Sensitivity analysis revealed that DOR values did not differ markedly, which indicates that the meta-analysis had strong reliability. Furthermore, this study demonstrated no proof of publication bias for DOR values analyzed using Egger's regression test (P > 0.05) and funnel plot. Interestingly, miR-15b, miR-21 and miR-31 presented the best diagnostic accuracy values for CRC with sensitivity, specificity, PLR, NLR, DOR, and AUC values of 0.95, 0.94, 17.19, 0.05, 324.81, and 0.948, respectively.

Conclusion

This study's findings indicated that miRNA panels, particularly serum-derived miRNA panels, can serve as powerful and promising biomarkers for early CRC screening.

Systematic review registration

[www.crd.york.ac.uk/prospero], identifier [CRD42021268172].

Association between Circulating MicroRNAs (miR-21-5p, miR-20a-5p, miR-29b-3p, miR-126-3p and miR-101-3p) and Chronic Allograft Dysfunction in Renal Transplant Recipients

Chronic allograft dysfunction (CAD) is a major condition affecting long-term kidney graft survival. Serum microRNA (miRNA) has been reported as a biomarker for various conditions of allograft injuries. The upregulation of miR-21 is the best-known miRNA change in graft tissue, urine and plasma. However, the correlation of plasma miR-21 with the severity of CAD remains unclear. In our study, 40 kidney transplantation recipients with late graft survival for more than 10 years were enrolled. The CAD group (n = 20) had either an eGFR between 15 to 60 mL/min or a biopsy-proved chronic allograft nephropathy or rejection. The control group (n = 20) had an eGFR ≥ 60 mL/min without proteinuria and hematuria for a consecutive 3 months before the study. We performed RNA sequencing to profile the miRNAs expression. There were six differentially expressed miRNAs in the CAD group. Among them, miR-21-5p and miR-101-3p were decreased, and miR-20a-5p was increased. We found that miR-21-5p, miR-20a-5p and miR-101-3p all participated in the TGF-beta pathway. We demonstrated that decreased miR-21-5p and miR-101-3p, and increased miR-20a-5p were the novel CAD-associated miRNAs in the TGF-beta pathway. These findings may pave the way for developing early prediction miRNAs biomarkers for CAD, and possibly developing therapeutic tools in the field of kidney transplantation.

Regulatory mechanism of miR-20a-5p expression in Cancer

MicroRNAs(miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes with a length of about 22 nucleotides. The dysregulation of miRNAs has been proven to be one of the vital causes of cancer, which makes them a biomarker for cancer diagnosis and prognosis. Compared with surgery and chemotherapy, nucleic acid therapy targeting specific miRNAs is a promising candidate for cancer treatment. miR-20a-5p plays an anticancer role in high-incidence human cancers such as cervical cancer, breast cancer and leukemia, which is of great importance in the diagnosis of cancers. The up-regulation and down-regulation of miR-20a-5p offers a possible breakthrough for the treatment of cancers. In this paper, we aim to investigate the functional significance of miR-20a-5p in different cancers, reviewing the expression differences of miR-20a-5p in cancer, while systematically summarizing the changes of circRNA-miR-20a-5p networks, and probe how it promotes messenger RNA (mRNA) degradation or inhibits mRNA translation to regulate downstream gene expression. We've also summarized the biogenesis mechanism of miRNAs, and emphasized its role in cell proliferation, cell apoptosis and cell migration. On this basis, we believe that miR-20a-5p is a promising and effective marker for cancer diagnosis, prognosis and treatment.

[miR-20a-5p inhibits proliferation of lung cancer A549 cells by down-regulating HOXB13]

OBJECTIVE

To investigate the molecular mechanism by which miR-20a-5p regulates HOXB13 gene expression and inhibits lung cancer cell proliferation.

METHODS

The expression levels of HOXB13 mRNA and protein in lung cancer A549 cells transfected with HOXB13 overexpression plasmid or HOXB13 siRNA were detected with real-time fluorescence quantitative PCR (qRT-PCR) and Western blotting. CCK-8 and EdU assays were used to examine the effect of modulation of HOXB13 expression on cell proliferation. We screened possible binding miRNAs of HOXB13 by bioinformatics analysis. In A549 cells transfected with miR-20a-5p mimic or miR-20a-5p inhibitor, the expression level of miR-20a-5p was detected by qRT-PCR and the protein expression of HOXB13 was determined with Western blotting. CCK-8 and EdU assays were used to assess the effect of miR-20a-5p overexpression on the proliferation of A549 cells. miR-20a-5p mimic and HOXB13 overexpression plasmids were co-transfected into A549 cells, and the changes in cell proliferation were evaluated with CCK-8 and EdU assays.

RESULTS

HOXB13 overexpression obviously promoted the proliferation of A549 cells (P < 0.05). miR-20a-5p was identified as the potential binding miRNA of HOXB13. Overexpression of miR-20a-5p in A549 cells significantly decreased the expression of HOXB13 protein (P < 0.05), while interference of miR-20a-5p obviously increased HOXB13 expression (P < 0.05). The results of cell proliferation experiment showed that miR-20a-5p and HOXB13 had opposite effects on cell proliferation, and the cells overexpressing both miR-20a-5p and HOXB13 showed a lower proliferation activity than the cells overexpressing HOXB13 but higher than the cells overexpressing miR-20a-5p alone (P < 0.05).

CONCLUSION

miR-20a-5p inhibits proliferation of lung cancer cells by down-regulating the expression of HOXB13.

Dexmedetomidine alleviates the hypoxic-ischemic brain damage via miR-20a-5p/methionine adenosyltransferase 2B axis in rat pups

OBJECTIVE

The neuroprotective effect of dexmedetomidine (DEX) has been demonstrated in hypoxic-ischemic brain damage (HIBD) animal models, the mechanism of which will be the foothold in this work.

METHODS

After establishment of HIBD rat model, the rats were treated with DEX, miR-20a-5p agomir and adenoviral methionine adenosyltransferase 2B (MAT2B) overexpression vector, and then their brain tissues were harvested. The infarction volume and pathological changes of these brain tissues were measured using the triphenyl tetrazolium chloride (TTC), Nissl and hematoxylin-eosin (HE) stainings. The levels of miR-20a-5p, Bcl-2, Bax and MAT2B in these brain tissues were detected by Real-Time PCR (RT-PCR) and western blot. The binding sites of MAT2B and miR-20a-5p were predicted using the TargetScan and verified using the dual-luciferase reporter assay. The memory deficits and spatial learning of rat pups were assessed by Morris water maze test.

RESULTS

MiR-20a-5p expression was upregulated, while MAT2B expression was downregulated in rats with HIBD. MAT2B was targeted by miR-20a-5p. DEX treatment improved the neurons and hippocampal tissue damage and decreased miR-20a-5p level in brain tissues of rats with HIBD. MiR-20a-5p overexpression overturned the protective effect of DEX on brain tissues and learning and memory abilities in rats with HIBD. Moreover, DEX promoted Bcl-2 level while inhibiting Bax level in HIBD rats' brain tissues. Besides, overexpressed MAT2B reversed the effect of overexpressed miR-20a-5p on the levels of MAT2B, Bcl-2 and Bax, brain tissue damage, as well as the learning and memory abilities in rats with HIBD.

CONCLUSION

DEX alleviated HIBD via the miR-20a-5p/MAT2B axis in rats.

Upregulation of miR-34a-5p, miR-20a-3p and miR-29a-3p by Onconase in A375 Melanoma Cells Correlates with the Downregulation of Specific Onco-Proteins

Onconase (ONC) is an amphibian secretory ribonuclease displaying cytostatic and cytotoxic activities against many mammalian tumors, including melanoma. ONC principally damages tRNA species, but also other non-coding RNAs, although its precise targets are not known. We investigated the ONC ability to modulate the expression of 16 onco-suppressor microRNAs (miRNAs) in the A375 BRAF-mutated melanoma cell line. RT-PCR and immunoblots were used to measure the expression levels of miRNAs and their regulated proteins, respectively. In silico study was carried out to verify the relations between miRNAs and their mRNA targets. A375 cell transfection with miR-20a-3p and miR-34a-5p mimics or inhibitors was performed. The onco-suppressors miR-20a-3p, miR-29a-3p and miR-34a-5p were highly expressed in 48-h ONC-treated A375 cells. The cytostatic effect of ONC in A375 cells was mechanistically explained by the sharp inhibition of cyclins D1 and A2 expression level, as well as by downregulation of retinoblastoma protein and cyclin-dependent-kinase-2 activities. Remarkably, the expression of kinases ERK1/2 and Akt, as well as of the hypoxia inducible factor-1α, was inhibited by ONC. All these proteins control pro-survival pathways. Finally, many crucial proteins involved in migration, invasion and metastatic potential were downregulated by ONC. Results obtained from transfection of miR-20a-3p and miR-34a-5p inhibitors in the presence of ONC show that these miRNAs may participate in the antitumor effects of ONC in the A375 cell line. In conclusion, we identified many intracellular downregulated proteins involved in melanoma cell proliferation, metabolism and progression. All mRNAs coding these proteins may be targets of miR-20a-3p, miR-29a-3p and/or miR-34a-5p, which are in turn upregulated by ONC. Data suggest that several known ONC anti-proliferative and anti-metastatic activities in A375 melanoma cells might depend on the upregulation of onco-suppressor miRNAs. Notably, miRNAs stability depends on the upstream regulation by long-non-coding-RNAs or circular-RNAs that can, in turn, be damaged by ONC ribonucleolytic activity.

MicroRNA-20a-5p Inhibits the Autophagy and Cisplatin Resistance in Ovarian Cancer via Regulating DNMT3B-mediated DNA Methylation of RBP1

Ovarian cancer (OvCa) is the third most common female malignancy worldwide and poses great threats on women health. Chemotherapy is the most recommended post-surgery treatment for OvCa patients; but, cisplatin resistance is a main cause of chemotherapy failure. In addition, autophagy modulates the sensitivity of tumor cells to chemotherapeutic agents. Hence, it is significant to explore the molecular mechanism concerning the autophagy and cisplatin resistance in OvCa. In this study, quantitative real-time PCR (qRT-PCR) was used to detect miR-20a-5p expression and western blot to measure RBP1 expression. A series of assays were conducted to explore the gain-of-function effects of miR-20a-5p. Luciferase reporter assay was applied to determine the downstream target of miR-20a-5p. The results proved that miR-20a-5p represses malignant phenotypes and autophagy in cisplatin-resistant OvCa cells. In addition, DNMT3B mediates DNA methylation of RBP1 to impair the promoting effects of RBP1 on carcinogenesis and autophagy in OvCa. Through rescue experiments, we certified that miR-20a-5p inhibits the autophagy and cisplatin resistance in OvCa via DNMT3B-mediated DNA methylation of RBP1. Collectively, we demonstrated that miR-20a-5p plays a crucial role in the modulation of autophagy and cisplatin resistance in OvCa, which might offer novel insights into developing effective treatment strategies for OvCa.

Identification of an Autophagy-Related Risk Signature Correlates With Immunophenotype and Predicts Immune Checkpoint Blockade Efficacy of Neuroblastoma

Neuroblastoma is one of the malignant solid tumors with the highest mortality in childhood. Targeted immunotherapy still cannot achieve satisfactory results due to heterogeneity and tolerance. Exploring markers related to prognosis and evaluating the immune microenvironment remain the major obstacles. Herein, we constructed an autophagy-related gene (ATG) risk model by multivariate Cox regression and least absolute shrinkage and selection operator regression, and identified four prognostic ATGs (BIRC5, GRID2, HK2, and RNASEL) in the training cohort, then verified the signature in the internal and external validation cohorts. BIRC5 and HK2 showed higher expression in MYCN amplified cell lines and tumor tissues consistently, whereas GRID2 and RNASEL showed the opposite trends. The correlation between the signature and clinicopathological parameters was further analyzed and showing consistency. A prognostic nomogram using risk score, International Neuroblastoma Staging System stage, age, and MYCN status was built subsequently, and the area under curves, net reclassification improvement, and integrated discrimination improvement showed more satisfactory prognostic predicting performance. The ATG prognostic signature itself can significantly divide patients with neuroblastoma into high- and low-risk groups; differentially expressed genes between the two groups were enriched in autophagy-related behaviors and immune cell reactions in gene set enrichment analysis (false discovery rate q -value < 0.05). Furthermore, we evaluated the relationship of the signature risk score with immune cell infiltration and the cancer-immunity cycle. The low-risk group was characterized by more abundant expression of chemokines and higher immune checkpoints (PDL1, PD1, CTLA-4, and IDO1). The risk score was significantly correlated with the proportions of CD8+ T cells, CD4+ memory resting T cells, follicular helper T cells, memory B cells, plasma cells, and M2 macrophages in tumor tissues. In conclusion, we developed and validated an autophagy-related signature that can accurately predict the prognosis, which might be meaningful to understand the immune microenvironment and guide immune checkpoint blockade.

A Focus on Regulatory Networks Linking MicroRNAs, Transcription Factors and Target Genes in Neuroblastoma

Neuroblastoma (NB) is a tumor of the peripheral sympathetic nervous system that substantially contributes to childhood cancer mortality. NB originates from neural crest cells (NCCs) undergoing a defective sympathetic neuronal differentiation and although the starting events leading to the development of NB remain to be fully elucidated, the master role of genetic alterations in key oncogenes has been ascertained: (1) amplification and/or over-expression of MYCN, which is strongly associated with tumor progression and invasion; (2) activating mutations, amplification and/or over-expression of ALK, which is involved in tumor initiation, angiogenesis and invasion; (3) amplification and/or over-expression of LIN28B, promoting proliferation and suppression of neuroblast differentiation; (4) mutations and/or over-expression of PHOX2B, which is involved in the regulation of NB differentiation, stemness maintenance, migration and metastasis. Moreover, altered microRNA (miRNA) expression takes part in generating pathogenetic networks, in which the regulatory loops among transcription factors, miRNAs and target genes lead to complex and aberrant oncogene expression that underlies the development of a tumor. In this review, we have focused on the circuitry linking the oncogenic transcription factors MYCN and PHOX2B with their transcriptional targets ALK and LIN28B and the tumor suppressor microRNAs let-7, miR-34 and miR-204, which should act as down-regulators of their expression. We have also looked at the physiologic role of these genetic and epigenetic determinants in NC development, as well as in terminal differentiation, with their pathogenic dysregulation leading to NB oncogenesis.

Circular RNA circPRKCI contributes to malignant progression of T-cell acute lymphoblastic leukemia by modulating miR-20a-5p/SOX4 axis

Circular RNAs (circRNAs) have demonstrated critical roles in the development of cancers. This study aimed to explore the function of circular RNA circPRKCI/miR-20a-5p/SOX4 axis in acute lymphoblastic leukemia (ALL). Our data showed that the expression of circPRKCI and SOX4 was enhanced while the expression of miR-20a-5p was reduced in the clinical T-ALL samples. The expression of miR-20a-5p was negatively associated with circPRKCI and SOX4 in the T-ALL patients and the expression of circPRKCI was positive correlated with SOX4 in the T-ALL patients. Functionally, the silencing of circPRKCI suppressed the viability of T-ALL cells. Conversely, the knockdown of circPRKCI promoted the apoptosis of T-ALL cells. The levels of cleaved PARP and cleaved caspase3 were induced by the depletion of circPRKCI in T-ALL cells. Mechanically, the luciferase activity of circPRKCI was significantly decreased in T-ALL cells after the treatment of miR-20a-5p mimic. Meanwhile, the silencing of circPRKCI promoted the expression of miR-20a-5p in T-ALL cells, implying that circPRKCI serves as a competitive endogenous RNAs (ceRNA) of miR-20a-5p. We validated that the treatment of miR-20a-5p mimic inhibited the viability of T-ALL cells. MiR-20a-5p mimic enhanced the apoptosis of T-ALL cells. The expression of cleaved PARP and cleaved caspase3 was increased by miR-20a-5p mimic in the cells. In summarization, we concluded that circular RNA circPRKCI contributed to malignant progression of T-cell acute lymphoblastic leukemia by modulating miR-20a-5p/SOX4 axis. Targeting circPRKCI may serve as a promising therapeutic strategy of T-ALL.

MiR-20a-5p functions as a potent tumor suppressor by targeting PPP6C in acute myeloid leukemia

Acute myeloid leukemia (AML) is as a highly aggressive and heterogeneous hematological malignancy. MiR-20a-5p has been reported to function as an oncogene or tumor suppressor in several tumors, but the clinical significance and regulatory mechanisms of miR-20a-5p in AML cells have not been fully understood. In this study, we found miR-20a-5p was significantly decreased in bone marrow from AML patients, compared with that in healthy controls. Moreover, decreased miR-20a-5p expression was correlated with risk status and poor survival prognosis in AML patients. Overexpression of miR-20a-5p suppressed cell proliferation, induced cell cycle G0/G1 phase arrest and apoptosis in two AML cell lines (THP-1 and U937) using CCK-8 assay and flow cytometry analysis. Moreover, miR-20a-5p overexpression attenuated tumor growth in vivo by performing tumor xenograft experiments. Luciferase reporter assay and western blot demonstrated that protein phosphatase 6 catalytic subunit (PPP6C) as a target gene of miR-20a-5p was negatively regulated by miR-20a-5p in AML cells. Furthermore, PPP6C knockdown imitated, while overexpression reversed the effects of miR-20a-5p overexpression on AML cell proliferation, cell cycle G1/S transition and apoptosis. Taken together, our findings demonstrate that miR-20a-5p/PPP6C represent a new therapeutic target for AML and a potential diagnostic marker for AML therapy.

MiR-20a-5p Regulates MPP+-Induced Oxidative Stress and Neuroinflammation in HT22 Cells by Targeting IRF9/NF-κB Axis

Substantial evidence indicates that microRNAs (miRNAs) can be used as biological markers of Parkinson's disease (PD) and contribute to the risk assessment, early diagnosis, and treatment. We aimed to explore the role and potential mechanism of miR-20a-5p on inflammation and oxidative stress in 1-methyl-4-phenyl pyridine ion- (MPP⁺-) induced HT22 cells. HT22 cells were pretreated with miR-20a-5p mimic and/or pcDNA-IRF9 for 24 h and then treated with MPP⁺ (0.5 mM) for 24 h. The cell viability and apoptosis were determined using the Cell Counting Kit-8 (CCK-8) and Annexin V FITC/PI staining flow cytometry assay, respectively. The expression and secretion of inflammatory factors and oxidative stress-related factors were detected by enzyme-linked immunosorbent assay (ELISA). The protein expression levels were detected using Western blot analysis. Here, we discovered that MPP⁺ led to mitochondrial dysfunction, inflammation, and cell damage of HT22 cells, which were alleviated by miR-20a-5p overexpression. We further clarified that interferon regulatory factor 9 (IRF9) was a target gene of miR-20a-5p. IRF9 contributed to MPP⁺-induced mitochondrial disruption, inflammation, and cell apoptosis. Moreover, IRF9 hindered the improvement of miR-20a-5p overexpression on MPP⁺-induced neurotoxicity. Furthermore, the decrease of p-P65 level induced by miR-20a-5p mimic was significantly reversed by IRF9 overexpression. These findings demonstrate that miR-20a-5p contributes to MPP⁺-induced mitochondrial disruption and cell damage, and miR-20a-5p might be a novel therapeutic target for PD.

Identification of functional lncRNAs through constructing a lncRNA-associated ceRNA network in myocardial infarction

Myocardial infarction (MI) is a type of coronary heart disease, which refers to the ischemic necrosis of the heart muscle. A large number of studies have discussed the mechanism of MI from the perspective of competing endogenous RNA (ceRNA) network. However, the mechanisms underlying the function of lncRNAs in MI have still not been explained in an explicit manner. Therefore, we constructed a scale-free lncRNA-associated ceRNA network to identify some crucial lncRNAs in MI. Results showed that the given disease genes for MI were involved in the network, the degrees of which were significantly larger than the other nodes of the network. For measuring the network centrality, we then constructed a hub subnetwork. The miRNAs and mRNAs in the hub subnetwork have been validated to function in MI-related biological function. In addition, we identified 2 MI-related functional modules from the lncRNA-associated ceRNA network, which suggested that lncRNA exerted function in local network. Enrichment analysis showed that these functional modules corresponded to some similar and different pathways related to cardiovascular disease. More importantly, 3 MI-related crucial lncRNAs, CTD-3092A11.2, RP5-821D11.7 and CTC-523E23.1 were detected as potential biomarkers, which may be involved in MI-related biological progresses. Our study identified 20 functional lncRNAs based on ceRNA network analysis, which may provide novel diagnosis and therapeutic targets for MI from the ceRNA network perspective.

Exosomal miRNA profiling from H5N1 avian influenza virus-infected chickens

Exosomes are membrane vesicles containing proteins, lipids, DNA, mRNA, and micro RNA (miRNA). Exosomal miRNA from donor cells can regulate the gene expression of recipient cells. Here, Ri chickens were divided into resistant (Mx/A; BF2/B21) and susceptible (Mx/G; BF2/B13) trait by genotyping of Mx and BF2 genes. Then, Ri chickens were infected with H5N1, a highly pathogenic avian influenza virus (HPAIV). Exosomes were purified from blood serum of resistant chickens for small RNA sequencing. Sequencing data were analysed using FastQCv0.11.7, Cutadapt 1.16, miRBase v21, non-coding RNA database, RNAcentral 10.0, and miRDeep2. Differentially expressed miRNAs were determined using statistical methods, including fold-change, exactTest using edgeR, and hierarchical clustering. Target genes were predicted using miRDB. Gene ontology analysis was performed using gProfiler. Twenty miRNAs showed significantly different expression patterns between resistant control and infected chickens. Nine miRNAs were up-regulated and 11 miRNAs were down-regulated in the infected chickens compared with that in the control chickens. In target gene analysis, various immune-related genes, such as cytokines, chemokines, and signalling molecules, were detected. In particular, mitogen-activated protein kinase (MAPK) pathway molecules were highly controlled by differentially expressed miRNAs. The result of qRT-PCR for miRNAs was identical with sequencing data and miRNA expression level was higher in resistant than susceptible chickens. This study will help to better understand the host immune response, particularly exosomal miRNA expression against HPAIV H5N1 and could help to determine biomarkers for disease resistance.

Overexpression of histone deacetylase SIRT1 exerts an antiangiogenic role in diabetic retinopathy via miR-20a elevation and YAP/HIF1α/VEGFA depletion

As a basic member of the Class III histone deacetylases, SIRT1 has been implicated in the occurrence and progression of diabetic retinopathy (DR). The current study aimed to investigate the roles of SIRT1/miR-20a/Yse-associated protein (YAP)/hypoxia-inducible factor 1 α (HIF1α)/vascular endothelial growth factor A (VEGFA) in DR. The expression of SIRT1 was initially determined through quantitative RT-PCR and Western blot analysis following the successful establishment of a DR mouse model, followed by detection of SIRT1 catalytic activity. Retinal microvascular endothelial cells (RMECs) were cultured in media supplemented with normal glucose (NG) or high glucose (HG). Thereafter, SIRT1 was either silenced or overexpressed in RMECs, after which EdU staining and Matrigel-based tube formation assay were performed to assess cell proliferation and tube formation. The binding relationship between YAP, HIF1α, and VEGFA was further illustrated using dual-luciferase reporter assay. Preretinal neovascular cell number was tallied with the IB4-positive vascular endothelial cells, as determined by immunofluorescence. SIRT1 was poorly expressed in mice with DR and HG-treated RMECs with low catalytic activity. The proliferation and tube formation capabilities of RMECs were elevated under HG conditions, which could be reversed following overexpression of SIRT1. SIRT1 was identified as positively regulating the expression of miR-20a with YAP detected as the key target gene of miR-20a. Our data suggested that YAP could upregulate VEGFA via induction of HIF1α. Moreover, SIRT1 overexpression strongly repressed RMEC proliferation and angiogenesis, which could be reversed via restoration of YAP/HIF1α/VEGFA expression. Taken together, the key findings of our study suggest that upregulation of SIRT1 inhibits the development of DR via miR-20a-induced downregulation of YAP/HIF1α/VEGFA.

Serum miRNAs associated with tumor-promoting cytokines in non-small cell lung cancer

Tumor-promoting cytokines are a cause of tumor progression; therefore, identifying key regulatory microRNAs (miRNAs) for controlling their production is important. The aim of this study is to identify promising miRNAs associated with tumor-promoting cytokines in non-small cell lung cancer (NSCLC). We identified circulating miRNAs from 16 published miRNA profiles. The selected miRNAs were validated in the serum of 32 NSCLC patients and compared with 33 patients with other lung diseases and 23 healthy persons using quantitative real-time PCR. The cytokine concentration was investigated using the enzyme-linked immunoassay in the same sample set, with clinical validation of the miRNAs. The correlation between miRNA expression and cytokine concentration was evaluated by Spearman’s rank correlation. For consistent direction, one up-regulated miRNA (miR-145) was found in four studies, and seven miRNAs were reported in three studies. One miRNA (miR-20a) and four miRNAs (miR-25-3p, miR-223, let-7f, and miR-20b) were reported in six and five studies. However, their expression was inconsistent. In the clinical validation, serum miR-145 was significantly down-regulated, whereas serum miR-20a was significantly up-regulated in NSCLC, compared with controls. Regarding serum cytokine, all cytokines [vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and transforming growth factor β (TGF-β)], except tumor necrosis factor-α (TNF-α), had a higher level in NSCLC patients than controls. In addition, we found a moderate correlation between the TGF-β concentration and miR-20a (r = −0.537, p = 0.002) and miR-223 (r = 0.428, p = 0.015) and a weak correlation between the VEGF concentration with miR-20a (r = 0.376, p = 0.037) and miR-223 (r = −0.355, p = 0.046). MiR-145 and miR-20a are potential biomarkers for NSCLC. In addition, the regulation of tumor-promoting cytokine, through miR-20a and miR-223, might be a new therapeutic approach for lung cancer.

Ischemia/reperfusion injured intestinal epithelial cells cause cortical neuron death by releasing exosomal microRNAs associated with apoptosis, necroptosis, and pyroptosis

To date, there is no good evidence that intestine epithelial cells (IEC) affected by ischemia/reperfusion (I/R) injury are able to cause cortical neuron injury directly. Additionally, it remains unclear whether the neuronal damage caused by I/R injured IEC can be affected by therapeutic hypothermia (TH, 32 °C). To address these questions, we performed an oxygen–glucose deprivation (OGD) affected IEC-6-primary cortical neuron coculture system under normothermia (37 °C) or TH (32 °C) conditions. It was found that OGD caused hyperpermeability in IEC-6 cell monolayers. OGD-preconditioned IEC-6 cells caused cortical neuronal death (e.g., decreased cell viability), synaptotoxicity, and neuronal apoptosis (evidenced by increased caspase-3 expression and the number of TUNEL-positive cells), necroptosis (evidenced by increased receptor-interacting serine/threonine-protein kinase-1 [RIPK1], RIPK3 and mixed lineage kinase domain-like pseudokinase [MLKL] expression), and pyroptosis (evidenced by an increase in caspase-1, gasdermin D [GSDMD], IL-1β, IL-18, the apoptosis-associated speck-like protein containing a caspase recruitment domain [ASC], and nucleotide oligomerization domain [NOD]-like receptor [NLRP]-1 expression). TH did not affect the intestinal epithelial hyperpermeability but did attenuate OGD-induced neuronal death and synaptotoxicity. We also performed quantitative real-time PCR to quantify the genes encoding 84 exosomal microRNAs in the medium of the control-IEC-6, the control-neuron, the OGD-IEC-6 at 37 °C, the OGD-IEC-6 at 32 °C, the neuron cocultured with OGD-IEC-6 at 37 °C, and the neurons cocultured with OGD-IEC-6 at 32 °C. We found that the control IEC-6 cell s or cortical neurons are able to secrete a basal level of exosomal miRNAs in their medium. OGD significantly up-regulated the basal level of each parameter for IEC-6 cells. As compared to those of the OGD-IEC-6 cells or the control neurons, the OGD-IEC-6 cocultured neurons had significantly higher levels of 19 exosomal miRNAs related to apoptosis, necroptosis, and/or pyroptosis events. Our results identify that I/R injured intestinal epithelium cells can induce cortical neuron death via releasing paracrine mediators such as exosomal miRNAs associated with apoptosis, necroptosis, and/or pyroptosis, which can be counteracted by TH.

Targeting autophagy in neuroblastoma

Background

Neuroblastoma (NB) is the most common extracellular solid tumor among children accounting for serious mortality. Macroautophagy, a common housekeeping mechanism to maintain cellular homeostasis in eukaryotic cells, is involved in tumorigenesis and chemoresistance in a spectrum of cancers.

Data resources

Based on the terms of ‘autophagy’ and ‘neuroblastoma’, all the recent literature was searched and reviewed through PubMed.

Results

Autophagy is associated with apoptosis, histone modifications, angiogenesis, metabolism in NB. With those facts we assume that NB is an autophagy-dependent tumor, which means that autophagy inhibition therapy is desirable.

Conclusion

Autophagy in NB is pro-oncogenic, so inhibiting autophagy in high-risk NB may benefit treatment outcomes.

Silencing miR-20a-5p inhibits axonal growth and neuronal branching and prevents epileptogenesis through RGMa-RhoA-mediated synaptic plasticity

Epileptogenesis is a potential process. Mossy fibre sprouting (MFS) and synaptic plasticity promote epileptogenesis. Overexpression of repulsive guidance molecule a (RGMa) prevents epileptogenesis by inhibiting MFS. However, other aspects underlying the RGMa regulatory process of epileptogenesis have not been elucidated. We studied whether RGMa could be modulated by microRNAs and regulated RhoA in epileptogenesis. Using microRNA databases, we selected four miRNAs as potential candidates. We further experimentally confirmed miR‐20a‐5p as a RGMa upstream regulator. Then, in vitro, by manipulating miR‐20a‐5p and RGMa, we investigated the regulatory relationship between miR‐20a‐5p, RGMa and RhoA, and the effects of this pathway on neuronal morphology. Finally, in the epilepsy animal model, we determined whether the miR‐20a‐5p‐RGMa‐RhoA pathway influenced MFS and synaptic plasticity and then modified epileptogenesis. Our results showed that miR‐20a‐5p regulated RGMa and that RGMa regulated RhoA in vitro. Furthermore, in primary hippocampal neurons, the miR‐20a‐5p‐RGMa‐RhoA pathway regulated axonal growth and neuronal branching; in the PTZ‐induced epilepsy model, silencing miR‐20a‐5p prevented epileptogenesis through RGMa‐RhoA‐mediated synaptic plasticity but did not change MFS. Overall, we concluded that silencing miR‐20a‐5p inhibits axonal growth and neuronal branching and prevents epileptogenesis through RGMa‐RhoA‐mediated synaptic plasticity in the PTZ‐induced epilepsy model, thereby providing a possible strategy to prevent epileptogenesis.

MiR-20a inhibits the progression of human arthritis fibroblast-like synoviocytes and inflammatory factor expression by targeting ADAM10

MiR-20a has been reported as a key regulator to pro-inflammatory factor release in fibroblast-like synoviocytes (FLS), which caused rheumatoid arthritis (RA). However, the molecular mechanism of miR-20a in RA remains to be further elucidated. This study aimed to investigate the roles of miR-20a in RA pathology. RA (n = 24) and osteoarthritis (OA, n = 20) and normal healthy tissues (n = 16) were collected from operation. TargetScan and dual-luciferase reporter were performed to predict and confirm the potential binding sites of miR-20a on ADAM metallopeptidase domain 10 (ADAM10). Pearson's analysis was adopted to evaluate the correlation between miR-20a and ADAM10 expression. It was found that MiR-20a was downregulated in RA tissues, and overexpressed miR-20a inhibited cell viability, migration and invasion, and the expression of inflammatory factors in RA-FLS MH7A cells. ADAM10 was identified as the target gene of miR-20a, and upregulation of ADAM10 reversed the inhibitory effects of miR-20a. In conclusion, miR-20a inhibits the progression of RA-FLS as well as the inflammatory factor expression by targeting ADAM10.

Combined Replenishment of miR-34a and let-7b by Targeted Nanoparticles Inhibits Tumor Growth in Neuroblastoma Preclinical Models

Neuroblastoma (NB) tumor substantially contributes to childhood cancer mortality. The design of novel drugs targeted to specific molecular alterations becomes mandatory, especially for high-risk patients burdened by chemoresistant relapse. The dysregulated expression of MYCN, ALK, and LIN28B and the diminished levels of miR-34a and let-7b are oncogenic in NB. Due to the ability of miRNA-mimics to recover the tumor suppression functions of miRNAs underexpressed into cancer cells, safe and efficient nanocarriers selectively targeted to NB cells and tested in clinically relevant mouse models are developed. The technology exploits the nucleic acids negative charges to build coated-cationic liposomes, then functionalized with antibodies against GD₂ receptor. The replenishment of miR-34a and let-7b by NB-targeted nanoparticles, individually and more powerfully in combination, significantly reduces cell division, proliferation, neoangiogenesis, tumor growth and burden, and induces apoptosis in orthotopic xenografts and improves mice survival in pseudometastatic models. These functional effects highlight a cooperative down-modulation of MYCN and its down-stream targets, ALK and LIN28B, exerted by miR-34a and let-7b that reactivate regulatory networks leading to a favorable therapeutic response. These findings demonstrate a promising therapeutic efficacy of miR-34a and let-7b combined replacement and support its clinical application as adjuvant therapy for high-risk NB patients.

Two novel mutations of PAX3 and SOX10 were characterized as genetic causes of Waardenburg Syndrome

Background

The objective of this study was to investigate the genetic causes of two probands diagnosed as Waardenburg syndrome (WS type I and IV) from two unrelated Chinese families.

Methods

PAX3 and SOX10 were the main pathogenic genes for WS type I (WS I) and IV (WS IV), respectively; all coding exons of these genes were sequenced on the two probands and their family members. Luciferase reporter assay and co‐immunoprecipitation (CO‐IP) were conducted to verify potential functional outcomes of the novel mutations.

Results

The first proband is a 9 years old girl diagnosed with WS I. A novel PAX3 heterozygous mutation of c.372‐373delGA (p.N125fs) was identified, which results in a frameshift and truncation of PAX3 protein. In family II, a 2 years old girl was diagnosed with WS IV, and Sanger sequencing revealed a de novo SOX10 mutation of c.1114insTGGGGCCCCCACACTACACCGAC (p.Q372fs), a frameshift mutation that extends the amino acid chain of SOX10 protein. Functional studies indicated that the novel mutation of SOX10 had no effects on the interaction of SOX10 and PAX3, but reduced transactivate capacity of melanocyte inducing transcription factor (MITF) promoter. Both PAX3 and SOX10 mutation‐induced defects of MITF transcription might contribute to the WS pathogenesis.

Conclusion

We revealed a novel mutation in PAX3 and a de novo mutation in SOX10, which might account for the underlying pathogenesis of WS. This study expands the database of both PAX10 and PAX3 mutations and improves our understanding of the causes of WS.

Function and mechanisms of microRNA-20a in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-associated mortality worldwide. CRC currently has no specific biomarkers to promote its diagnosis and treatment and the underlying mechanisms regulating its pathogenesis have not yet been determined. MicroRNAs (miRs) are small, non-coding RNAs that exhibit regulatory functions and have been demonstrated to serve a crucial role in the post-transcriptional regulatory processes of gene expression that is associated with cell physiology and disease progression. Recently, abnormal miR-20a expression has been identified in a number of cancers types and this has become a novel focus within cancer research. High levels of miR-20a expression have been identified in CRC tissues, serum and plasma. In a recent study, miR-20a was indicated to be present in feces and to exhibit a high sensitivity to CRC. Therefore, miR-20a may be used as a marker for CRC and an indicator that can prevent the invasive examination of patients with this disease. Changes in the expression of miR-20a during chemotherapy can be used as a biomarker for monitoring resistance to treatment. In conclusion, miR-20a exhibits the potential for clinical application as a novel diagnostic biomarker and therapeutic target for use in patients with CRC. The present study focused on the role and mechanisms of miR-20a in CRC.

Role of GOLPH3 and TPX2 in Neuroblastoma DNA Damage Response and Cell Resistance to Chemotherapy

Neuroblastoma (NB) is an aggressive, relapse-prone infancy tumor of the sympathetic nervous system and is the leading cause of death among preschool age diseases, so the search for novel therapeutic targets is crucial. Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development, and in the DNA damage response, of various human cancers. Golgi dispersal is a common feature of DNA damage response in mammalian cells. Understanding how cells react to DNA damage is essential in order to recognize the systems used to escape from elimination. We induced DNA damage in two human neuroblastoma cell lines by curcumin. The exposure of neuroblastoma cells to curcumin induced: (a) up-regulation of GOLPH3⁺ cells; (b) augmentation of double-strand breaks; (c) Golgi fragmentation and dispersal throughout the cytoplasm; (d) increase of apoptosis and autophagy; (e) increased expression of TPX2 oncoprotein, able to repair DNA damage. Primary neuroblastoma samples analysis confirmed these observations. Our findings suggest that GOLPH3 expression levels may represent a clinical marker of neuroblastoma patients’ responsiveness to DNA damaging therapies—and of possible resistance to them. Novel molecules able to interfere with GOLPH3 and TPX2 pathways may have therapeutic benefits when used in combination with standard DNA damaging therapeutic agents in neuroblastoma

Genome-Wide CRISPR Screen Reveals Autophagy Disruption as the Convergence Mechanism That Regulates the NRF2 Transcription Factor

The nuclear factor (erythroid 2)-like 2 (NRF2 or NFE2L2) transcription factor regulates the expression of many genes that are critical in maintaining cellular homeostasis. Its deregulation has been implicated in many diseases, including cancer and metabolic and neurodegenerative diseases. While several mechanisms by which NRF2 can be activated have gradually been identified over time, a more complete regulatory network of NRF2 is still lacking. Here we show through a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screen that a total of 273 genes, when knocked out, will lead to sustained NRF2 activation. Pathway analysis revealed a significant overrepresentation of genes (18 of the 273 genes) involved in autophagy. Molecular validation of a subset of the enriched genes identified 8 high-confidence genes that negatively regulate NRF2 activity irrespective of cell type: ATG12, ATG7, GOSR1, IFT172, NRXN2, RAB6A, VPS37A, and the well-known negative regulator of NRF2, KEAP1 Of these, ATG12, ATG7, KEAP1, and VPS37A are known to be involved in autophagic processes. Our results present a comprehensive list of NRF2 negative regulators and reveal an intimate link between autophagy and NRF2 regulation.

miR-20a suppresses chondrogenic differentiation of ATDC5 cells by regulating Atg7

Both the miR-17-92 cluster and autophagy have been suggested as critical regulators of bone development, but the potential correlation between the two factors is largely unknown. Hence, we investigated whether members of this cluster can regulate chondrogenesis through an autophagy-related signalling pathway. In this study, the expression of miR-17-92 cluster members and the level of autophagic activity were investigated during chondrogenic induction in ATDC5 cells. miR-17, miR-18a, miR-20a, and miR-92-1 showed significant changes, and the level of autophagic activity was enhanced. Among the miR-17-92 cluster members, miR-20a showed the most significant change. Histological, cellular and molecular analyses were performed after the regulation of miR-20a and autophagy. miR-20a and autophagy had the opposite effect on chondrogenic differentiation, and there was a negative correlation between them. Moreover, the expression of the autophagy regulatory gene Atg7 was inhibited by miR-20a. siRNA was then used to knock down Atg7, and the results further indicated that Atg7 might be a potential target of miR-20a in chondrogenic differentiation. In conclusion, miR-20a is a critical negative regulator of chondrogenic differentiation because it inhibits autophagy via Atg7. Other members of the miR-17-92 cluster may have a similar effect, but this hypothesis requires further investigation.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

Melatonin benefits to the growth of human annulus fibrosus cells through inhibiting miR-106a-5p/ATG7 signaling pathway

BACKGROUND

Disc degeneration (DD) is one of the common diseases worldwide, which deeply influences normal life and leads to excruciating pain. However, an effective treatment for DD is still not identified.

METHOD

The present study systemically examined the effect of melatonin on annulus fibrosus (AF) cells of patients with DD.

RESULTS

Melatonin had the effect of promoting proliferation, inducing autophagy, and suppressing apoptosis on AF cells of patients with DD. Moreover, melatonin contributed to the translation and transcription of autophagy-related protein ATG7 and inhibited the function of miR-106a-5p in AF cells. In addition, the results suggested that miR-106a-5p mediated the expression of ATG7 by directly binding to its 3'UTR in AF cells.

CONCLUSION

This research not only gained a deep insight of melatonin mode of action, but also indicated its potential target signaling pathway in AF cells.

MicroRNA‑154 functions as a tumor suppressor in bladder cancer by directly targeting ATG7

Aberrant expression of miR‑154 is usually found in cancer studies; however, the role of miR‑154 has seldom been reported in bladder cancer (BCa). In this study, we observed that miR‑154 expression was significantly downregulated in BCa tissues and cell lines, and was associated with several clinicopathological characteristics, including advanced T stage, lymphatic invasion, and distant metastasis. Low expression level of miR‑154 was associated with poor survival outcomes in BCa patients. Overexpression of miR‑154 led to significant decrease in the proliferation, migration, and invasion of BCa cells, while knockdown of miR‑154 yielded the opposite effect. ATG7 was identified as a direct target of miR‑154. ATG7 expression was negatively correlated with miR‑154 expression in BCa tissues. Silencing of ATG7 achieved a similar effect to miR‑154 overexpression; overexpression of ATG7 reversed the inhibitory effect of miR‑154 on BCa cell proliferation, migration and invasion. A xenograft study revealed that miR‑154 inhibited BCa cell growth in vivo, and suppressed ATG7 expression. Altogether, this study demonstrated that miR‑154 may function as a tumor suppressor in BCa and indicated that miR‑154 may be a potential therapeutic target for BCa patients.

Emerging microRNA biomarkers for colorectal cancer diagnosis and prognosis

MicroRNAs (miRNAs) are one abundant class of small, endogenous non-coding RNAs, which regulate various biological processes by inhibiting expression of target genes. miRNAs have important functional roles in carcinogenesis and development of colorectal cancer (CRC), and emerging evidence has indicated the feasibility of miRNAs as robust cancer biomarkers. This review summarizes the progress in miRNA-related research, including study of its oncogene or tumour-suppressor roles and the advantages of miRNA biomarkers for CRC diagnosis, treatment and recurrence prediction. Along with analytical technique improvements in miRNA research, use of the emerging extracellular miRNAs is feasible for CRC diagnosis and prognosis.

MiR-129-3p favors intracellular BCG survival in RAW264.7 cells by inhibiting autophagy via Atg4b

Autophagy plays an important role in the fight against Mycobacterium tuberculosis infection. Massive researches proved that miRNAs could be the regulators of autophagy, which implied miRNAs could favor MTB invasion or latent infection. In our study, multiple bioinformatics databases and software were used to seek and lock the miRNAs associating with regulation of autophagy. Notably, a novel miR-129-3p was found and its target gene Atg4b showed grand potential in mediation of autophagy. Moreover, BCG infection triggered miR-129-3p overexpression in RAW264.7 cells. Up-regulation of miR-129-3p decreased mRNA or protein level of Atg4b and resulted in the inhibition of autophagy. The antagomir of miR-129-3p had the opposite impact. The LC3 puncta formation in RAW264.7 cells were also affected after transfection of miR-129-3p mimic or antagomir. The mRFP-GFP-LC3 analysis indicated that mimic of miR-129-3p impaired autophagic flux while antagomir improved autophagy. The CFU assay results showed that miR-129-3p promoted the intracellular survival of BCG in macrophages. Consequently, these data suggested that miR-129-3p could favor MTB survival by inhibiting autophagy via Atg4b.

MicroRNA-20a regulates cell proliferation, apoptosis and autophagy by targeting thrombospondin 2 in cervical cancer

Cervical cancer (CC) is the fourth most frequent malignancy worldwide. MicroRNAs (miRNAs) can function as potential biomarkers or therapeutic targets in multiple cancers including CC. Our present study aimed to investigate the roles and downstream targets of microRNA-20a (miR-20a) in regulating CC proliferation, apoptosis and autophagy. Here, RT-qPCR assay revealed that miR-20a was highly expressed in CC tissues and cells. Functional analysis showed that the inhibition of miR-20a resulted in reduced proliferation, increased apoptosis and downregulated autophagic activity in CC cells. Bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation (RIP) assay manifested that thrombospondin 2 (THBS2) was a target of miR-20a. Also, THBS2 expression was notably reduced in CC tissues and cells, and inversely associated with miR-20a expression in CC tissues. Restoration experiments disclosed that THBS2 knockdown abrogated miR-20a inhibitor-mediated anti-proliferation, pro-apoptosis, and anti-autophagy effects in CC cells. In summary, these data showed that the depletion of miR-20a suppressed proliferation and autophagy and induced apoptosis by targeting THBS2 in CC cells, further elucidating the roles and molecular basis of miR-20a in the development of CC.