Exosome-Transmitted miR-224-5p Promotes Colorectal Cancer Cell Proliferation via Targeting ULK2 in p53-Dependent Manner

Objective

To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer (CRC).

Methods

The miR-224-5p expression in CRC patient tissues and cell-derived exosomes was measured by laser capture microdissection and qRT-PCR, respectively. Dual-luciferase reporter gene assay was used to determine the target gene of miR-224-5p. The protein expressions of p53 and unc-51 like kinase 2 (ULK2) in CRC cells were detected by western blot. Flow cytometry was used to detect cell cycle and apoptosis. Cell proliferation was measured by CCK8 and EdU assay.

Results

The miR-224-5p expression was upregulated in CRC tissues and increased progressively with the rise of CRC stage. CRC cells secreted extracellular miR-224-5p mainly in an exosome-dependent manner, and then miR-224-5p could be transferred to surrounding tumor cells to regulate cell proliferation in the form of autocrine or paracrine. Moreover, ULK2 was characterized as a direct target of miR-224-5p and was downregulated in CRC tissues. Interestingly, ULK2 inhibited CRC cell proliferation in a p53-dependent manner. Furthermore, exosome-derived miR-224-5p partially reversed the proliferation regulation of ULK2 on CRC cells.

Conclusion

Our findings demonstrate that exosome-transmitted miR-224-5p promotes p53-dependent cell proliferation by targeting ULK2 in CRC, which may offer promising targets for CRC prevention and therapy.

The miR-224-5p/SIRT3/AMPK/mTOR axis is involved in the melatonin-mediated inhibition of glucocorticoid-induced osteoporosis by activating autophagy

Melatonin has been shown to exert an inhibitory effect on osteoporosis. This study investigates the function of the miR-224-5p/SIRT3/AMPK/mTOR axis in melatonin-mediated effects against osteoporosis. Human bone marrow mesenchymal stem cells (hBMSCs) were treated with glucocorticoid dexamethasone to induce an in vitro osteoporosis model. After melatonin treatment, miR-224-5p and SIRT3 levels were measured by RT‒PCR. Transmission electron microscopy and immunofluorescence were conducted for evaluating autophagy. Western blotting was carried out to determine the expression of osteogenesis-related proteins (Runx2, OSX, OPN, and OCN), SIRT3-AMPK-mTOR axis, and autophagy-related markers (LC3 and p62). Alizarin red staining was used to measure matrix mineralization. The data showed that melatonin inhibited dexamethasone-induced osteoporosis in vitro, and enhanced autophagic levels (as indicated by increased LC3 puncta, LC3II/I ratio, and autophagic vacuoles). In terms of the mechanisms, melatonin decreased miR-224-5p expression and increased SIRT3. SRIT3 was shown to be a direct target of miR-224-5p. miR-224-5p upregulation or SIRT3 downregulation reversed the effects of melatonin on osteoporosis and suppressed autophagy. Additionally, miR-224-5p inhibited SIRT3 expression and AMPK pathway activation. In summary, we discovered that melatonin suppressed glucocorticoid-induced osteoporosis and autophagy inhibition via the miR-224-5p/SIRT3/AMPK/mTOR axis.

Knockdown of circSOD2 ameliorates osteoarthritis progression via the miR-224-5p/PRDX3 axis

BACKGROUND

Although the implications of circular RNAs (circRNAs) with the progression of diverse pathological conditions have been reported, the circRNA players in osteoarthritis (OA) are barely studied.

METHODS

In this study, twenty-five OA patients who received arthroplasty were recruited for cartilage tissue collection. Public circRNA microarray data from Gene Expression Omnibus was retrieved for circRNA identification. An in vitro cell model of OA-related damages was constructed by treating human chondrocytes (CHON-001 cell line) with IL-1β, and circSOD2 siRNA was used to silence circSOD2 expression to study its functional role in apoptosis, inflammatory responses, and extracellular matrix (ECM) degradation. Besides, we investigated the functional interactions among circSOD2, miR-224-5p, and peroxiredoxin 3 (PRDX3) by luciferase reporter assay, RNA-immunoprecipitation assay, and quantitative reverse transcription polymerase chain reaction.

RESULTS

Our findings revealed the overexpression of circSOD2 in the OA cartilage and cell samples, and circSOD2 knockdown alleviated ECM degradation, inflammation, and apoptosis in CHON-001 cell model. In addition, our findings suggested the regulatory function of circSOD2 knockdown on miR-224-5p expression, while miR-224-5p was capable of downregulating PRDX3 expression. The co-transfection of miR-224-5p inhibitor or pcDNA-PRDX3 could prevent the effect of circSOD2 knockdown.

CONCLUSION

Hence, our results demonstrated that knockdown of circSOD2 may serve as an intervention strategy to alleviate OA progression through modulating miR-224-5p/PRDX3 signaling axis.

Circ_0007624 suppresses the development of esophageal squamous cell carcinoma via targeting miR-224-5p/CPEB3 to inactivate the EGFR/PI3K/AKT signaling

Circular RNAs (circRNAs) have been confirmed to be involved in the regulation of esophageal squamous cell carcinoma (ESCC) progression. According to GEO datasets (GSE112496 and GSE150476), we identified that circ_0007624 was abnormally down-regulated in ESCC. However, there is still no reports regarding the function and mechanism of circ_0007624 in ESCC development. Here, we found that circ_0007624 was significantly underexpressed in ESCC tissues, and low expression of circ_0007624 was indicative of a poor prognosis. Overexpressing circ_0007624 or silencing miR-224-5p suppressed cell proliferation, metastasis, epithelial-mesenchymal transition (EMT), and promoted apoptosis in vitro. Also, circ_0007624 up-regulation slowed ESCC tumor growth in vivo. Mechanistically, circ_0007624 could serve as a competing endogenous RNA (ceRNA) by sponging miR-224-5p to antagonize its inhibitory effect on the target cytoplasmic polyadenylation element binding protein 3 (CPEB3). Rescue experiments showed that the anti-cancer properity role of circ_0007624 in ESCC is partly reversed by the restoration of miR-224-5p or down-regulation of CPEB3. Furthermore, EGFR/PI3K/AKT pathway was involved in the regulation of circ_0007624/miR-224-5p/CPEB3 axis in ESCC. Together, our findings demonstrate for the first time that circ_0007624/miR-224-5p/CPEB3 suppresses ESCC progression by inactivating EGFR/PI3K/AKT signaling, providing a basis for developing circ_0007624-targeted therapies for ESCC patients.

Mechanism of METTL14 and m6A modification of lncRNA MALAT1 in the proliferation of oral squamous cell carcinoma cells

OBJECTIVES

Methyltransferase-like 14 (METTL14) plays an epigenetic role in various cancer through N6-methyladenosine (m6A) modification. This study sought to analyze the mechanism of METTL14 in oral squamous cell carcinoma (OSCC) cell proliferation.

METHODS

Expression levels of METTL14, lncRNA metastasis associated with lung adenocarcinoma transcript 1 (lncRNA MALAT1), microRNA (miR)-224-5p, and histone lysine demethylase 2A (KDM2A) in OSCC tissues (N = 40), and cell lines (FaDu, SCC-25, CAL-27, and SCC-15) were detected. Cell viability and colony formation capacity were assessed. m6A level, stability, and subcellular localization of lncRNA MALAT1 were determined. Nude mouse xenograft tumor assay was performed to confirm the role of METTL14 in vivo.

RESULTS

METTL14 and lncRNA MALAT1 were upregulated, and miR-224-5p was downregulated in OSCC tissues and cells. Silencing METTL14 repressed OSCC cell viability and colony formation. Overexpression of MALAT1 and KDM2A or miR-224-5p downregulation reversed the inhibition of silencing METTL14 on OSCC cell proliferation. METTL14 induced m6A modification of MALAT1 to upregulate MALAT1. MALAT1 is comparatively bound to miR-224-5p to promote KDM2A transcription. In vivo, METTL14 promoted tumor growth via regulating MALAT1/miR-224-5p/ KDM2A.

CONCLUSIONS

Overall, our findings verified the therapeutic role of silencing METTL14 in OSCC treatment through the MALAT1/miR-224-5p/KDM2A axis.

miR-224-5p and miR-545-5p Levels Relate to Exacerbations and Lung Function in a Pilot Study of X-Linked MicroRNA Expression in Cystic Fibrosis Monocytes

Altered microRNA expression patterns in bronchial brushings from people with versus without cystic fibrosis (CF) relate to functional changes and disease pathophysiology. The expression of microRNAs encoded on the X chromosome is also altered in peripheral blood monocytes of p. Phe508del homozygous versus non-CF individuals. Here we investigate whether levels of the top seven X-linked microRNAs (miR-224-5p, miR-452-5p, miR-450b-5p, miR-542-3p, miR-450a-5p, miR-424-5p, and miR-545-5p) that are significantly increased over 1.5 fold in CF versus non-CF monocytes correlate with lung function. CD14⁺ monocytes were isolated from males and females with (n = 12) and without cystic fibrosis (n = 12) and examined for the expression of X-linked microRNAs by qRT-PCR array. MicroRNA target mRNA levels were quantified using qRT-PCR. Clinical correlations with lung function data were analysed in the CF cohort. Increasing levels of miR-545-5p correlated moderately with FEV1% predicted (r = -0.4553, p > 0.05) and strongly with exacerbation rate (r = 0.5858, p = 0.0483). miR-224-5p levels were significantly higher in the severe (FEV1 <40%) versus mild (FEV1 ≥80%, p = 0.0377) or moderate (FEV1 40-79%, p = 0.0350) groups. MiR-224-5p expression inversely correlated with lung function (FEV1%: r = -0.5944, p = 0.0457) and positively correlated with exacerbation rates (r = 0.6139, p = 0.0370). These data show that peripheral blood monocyte miR-545-5p and miR-224-5p levels correlate with exacerbation rate, whilst miR-224-5p levels also correlate with lung function in cystic fibrosis.

Overexpression of miR-224-5p alleviates allergic rhinitis in mice via the TLR4/MyD88/NF-κB pathway

Inflammatory allergic reaction is the main cause of allergic rhinitis (AR). Previous studies indicated that miR-224-5p was downregulated in the nasal mucosa of patients with AR, while the function of miR-224-5p in AR remains unclear. To explore this issue, AR mouse model was established using ovalbumin (OVA). For treatment group, lentivirus (LV)-miR-224-5p or its control was intranasally administrated to AR mice. miR-224-5p expression was detected by reverse transcription-quantitative PCR, followed by assessing the immunoglobulin E (IgE) level. Pathological alterations in nasal mucosa were detected using Hematoxylin-Eosin staining and Sirius red staining, followed by assessing the levels of inflammatory cells and factors. The NLRP3 inflammasome and TLR4/MyD88/NF-κB pathway were measured by Western blot, and then the relationship between miR-224-5p and toll-like receptor 4 (TLR4) was verified. The results showed that miR-224-5p was significantly decreased in nasal mucosa of AR mice. AR mice exhibited increased sneezing and nasal rubbing events, IgE level in serum, and pathological alterations in nasal mucosa, while overexpression of miR-224-5p markedly attenuated these changes. The levels of inflammatory cells in nasal lavage fluid and pro-inflammatory factors in serum and nasal mucosa were significantly increased in AR mice, which were reduced by miR-224-5p overexpression. Of note, LV-miR-224-5p treatment remarkably suppressed the activations of NLRP3 inflammasome and the TLR4/MyD88/NF-κB pathway in AR mice. Furthermore, miR-224-5p could bind to 3'-untranslated region (3'-UTR) of TLR4 and negatively regulate TLR4 level. Overall, we conclude that miR-224-5p may relieve AR by negatively regulating TLR4/MyD88/NF-κB pathway, indicating that miR-224-5p may be a promising target for AR treatment.

Circ-LDLRAD3 Enhances Cell Growth, Migration, and Invasion and Inhibits Apoptosis by Regulating MiR-224-5p/NRP2 Axis in Gastric Cancer

BACKGROUND

Emerging as a newly discovered type of noncoding RNAs, circular RNAs have been manifested as a crucial regulator in tumorigenesis of human malignancies, including gastric cancer (GC). Although circ-LDLRAD3 has been revealed as an oncogene in pancreatic cancer, the underlying role of circ-LDLRAD3 in GC remains poorly understood.

AIMS

Exploring the underlying function of circ-LDLRAD3 on GC progression.

METHODS

Circ-LDLRAD3 expression was detected through RT-qPCR. EdU, colony formation, TUNEL, and transwell assays were performed to analyze the function of circ-LDLRAD3 on GC progression. Luciferase reporter and RIP assays were applied to testify the interaction between circ-LDLRAD, miR-224-5p, and NRP2 in GC.

RESULTS

We detected preliminarily the expression of circ-LDLRAD3 and observed a markedly high expression of circ-LDLRAD3 in GC cells. Besides, circ-LDLRAD3 was featured with loop structure. Biological function assays testified that silenced circ-LDLRAD3 inhibited cell proliferation, migration, and invasion capacity but facilitated apoptosis of GC cells. Molecular mechanism assays uncovered that circ-LDLRAD3 combined with miR-224-5p in GC. Moreover, rescue assays delineated that inhibited expression of miR-224-5p could restore the inhibitive influence of circ-LDLRAD3 knockdown on the progression of GC. Moreover, neuropilin 2 (NRP2) was a downstream target of miR-224-5p. Additionally, circ-LDLRAD3 regulated NRP2 expression by sponging miR-224-5p in GC. Furthermore, circ-LDLRAD3 depletion-mediated effect on GC progression could be reversed by overexpressing NRP2.

CONCLUSIONS

Circ-LDLRAD3 facilitates GC progression by regulating miR-224-5p/NRP2 axis, providing new insights for the researches of GC treatment.

Hsa_circ_0001021 regulates intestinal epithelial barrier function via sponging miR-224-5p in ulcerative colitis

Aims: Few circRNAs have been thoroughly explored in ulcerative colitis (UC). Materials & methods: Microarrays and qualitative real-time PCRs were used to detect and confirm dysregulated circRNAs associated with UC. Functional analysis was performed to explore the roles. Results: A total of 580 circRNAs and 87 miRNAs were simultaneously dysregulated in both inflamed and noninflamed UC colonic mucosa compared with healthy controls. Accordingly, hsa_circ_0001021 was significantly downregulated in patients with UC and was related to Mayo scores. Clinical samples and cell experiments revealed that hsa_circ_0001021 was expressed in epithelial cells and correlated with ZO-1, occludin and CLDN-2. Moreover, hsa_circ_0001021 sponged miR-224-5p to upregulate smad4 and increased ZO-1 and occludin. Conclusion: Hsa_circ_0001021 is related to UC severity and regulates epithelial barrier function via sponging miR-224-5p.

Hsa_circ_0134111 promotes osteoarthritis progression by regulating miR-224-5p/CCL1 interaction

Mechanical, metabolic, inflammatory, and immune factors contribute to the development of osteoarthritis (OA), a joint disease characterized by cartilage destruction. The circular RNA (circRNA) hsa_circ_0134111 is upregulated in the cartilage of OA patients; however, its potential role in OA pathogenesis and progression remains unexplored. In this study, the effects of hsa_circ_0134111 knockdown were evaluated in primary human chondrocytes treated with IL-1β to simulate OA, as well as in a rat model of OA. Hsa_circ_0134111 expression was upregulated in IL-1β-stimulated chondrocytes. CCK-8 and flow cytometry assays showed that hsa_circ_0134111 knockdown reversed IL-1β-induced cell decline by inhibiting apoptosis. Following prediction analysis of circRNA and miRNA targets, dual-luciferase reporter and silencing/overexpression assays suggested that a regulatory network composed of hsa_circ_0134111, miR-224-5p, and CCL1 modulates IL-1β-mediated OA-like effects in chondrocytes. Accordingly, CCL1 overexpression abrogated the prosurvival effects of hsa_circ_0134111 knockdown in vitro. Moreover, hsa_circ_0134111 silencing in vivo alleviated cartilage destruction in an OA rat model, decreased IL-6 and TNF-α levels in synovial fluid, and downregulated CCL1 expression in the affected joints. These results suggest that hsa_circ_0134111 contributes to OA development by binding to miR-224-5p, thereby releasing the inhibition that miR-224-5p exerts over CCL1.

MiR-224-5p Targeting OCLN Promotes the Proliferation, Migration, and Invasion of Clear Cell Renal Cell Carcinoma Cells

A number of studies reported that miR-224-5p is involved in a variety of cancer-related cellular processes, yet its physiological role in clear cell renal cell carcinoma (ccRCC) remains unclear. In order to clarify the function of miR-224-5p in ccRCC, real-time quantitative-PCR was conducted to compare the expression of miR-224-5p in human normal renal tubular epithelial cell lines and ccRCC cell lines first, and a strikingly upregulated expression was observed in ccRCC cell lines. Inhibition of miR-224-5p expression by microRNA inhibitors could inhibit the proliferation, migration, and invasion of ccRCC cells. Besides, it was validated by dual-luciferase assay in which miR-224-5p directly targeted OCLN gene. The expression of OCLN was downregulated in ccRCC cells, and overexpression of miR-224-5p could inhibit the mRNA and protein expression levels of OCLN. Overexpression of OCLN could reduce the proliferation, migration, and invasion of ccRCC cells, while overexpressed miR-224-5p could partially reverse that inhibitory effect. Therefore, the promotive effect of miR-224-5p on the proliferation, invasion, and migration of ccRCC cell lines was at least partly due to the inhibition of OCLN expression. These findings highlighted the important function of miR-224-5p, which was promoting cell proliferation, migration, and invasion by downregulating OCLN, in the pathogenesis of ccRCC, and provided a potential treatment strategy.

The LncRNA MIR503HG/miR-224-5p/TUSC3 Signaling Cascade Suppresses Gastric Cancer Development via Modulating ATF6 Branch of Unfolded Protein Response

Background

Unfolded protein response (UPR)-mediated tumor-promoting functions have been identified in multiple cancers, and this study focused on investigating the role and molecular mechanisms of UPR in modulating gastric cancer (GC) pathogenesis.

Methods

The bioinformatics analysis was performed to examine the expression status of cancer associated genes in patients with stomach adenocarcinoma (STAD) and predict the targeting sites of miR-224-5p with LncRNA MIR503HG and TUSC3. Genes expressions were quantified by Real-Time qPCR, Western Blot and immunohistochemistry (IHC). Cell proliferation, viability, apoptosis and mobility were evaluated by MTT assay, trypan blue staining assay, flow cytometer and transwell assay, respectively. The binding sites were validated by dual-luciferase reporter gene system assay.

Results

LncRNA MIR503HG and TUSC3 were downregulated, but miR-224-5p was upregulated in GC tissues and cells, in contrast with their normal counterparts. Further gain- and loss-of-function experiments validated that the malignant phenotypes in GC cells, including cell proliferation, invasion, epithelial-mesenchymal transition (EMT) and tumorigenesis, were negatively regulated by LncRNA MIR503HG. Mechanistically, LncRNA MIR503HG upregulated TUSC3 in GC cells through sponging miR-224-5p, resulting in the repression of GC progression. Finally, we validated that knock-down of ATF6, but not other two branches of UPR (PERK1 and IRE1), partially rescued cell proliferation and EMT in the GC cells with LncRNA MIR503HG overexpression.

Conclusions

Targeting the LncRNA MIR503HG/miR-224-5p/TUSC3 signaling cascade suppressed ATF6-mediated UPR, resulting in the blockage of GC development.

Extracellular vesicles derived from cancer-associated fibroblast carries miR-224-5p targeting SLC4A4 to promote the proliferation, invasion and migration of colorectal cancer cells

More and more studies indicated that extracellular vesicles (EVs) carrying miRNAs have been potential biomarkers of various cancers including colorectal cancer (CRC). This study aims to explore the function of miR-224-5p carried by EVs derived from cancer-associated fibroblasts (CAFs) in CRC. Here, we found that miR-224-5p was highly expressed while SLC4A4 was lowly expressed in CRC cells. Moreover, dual-luciferase reporter gene assay testified that miR-224-5p targeted SLC4A4. The expression of miR-224-5p in CAFs-derived EVs was found to be elevated. It was also testified that CAFs-derived EVs could transfer miR-224-5p into CRC cells. miR-224-5p in CAFs-derived EVs facilitated the proliferation, migration, invasion and anti-apoptosis of CRC cells. Overexpressing miR-224-5p increased the proliferative, migratory and invasive abilities of CRC cells and inhibit CRC cell apoptosis, while overexpressing SLC4A4 caused the opposite result. Research in vitro and in vivo further indicated that miR-224-5p promoted CRC cell progression via binding to its downstream target gene SLC4A4. Rescue assay also demonstrated that overexpressing miR-224-5p reversed the inhibitory effect of overexpressed SLC4A4 on cancer cell growth. In addition, in vivo assay identified that high level of miR-224-5p promoted the growth of cancer cells in mice in vivo. In conclusion, we explored the effect of miR-224-5p in CRC, which helps for further exploration of new methods for CRC targeted therapy.

The Long Non-coding RNA NEAT1/miR-224-5p/IL-33 Axis Modulates Macrophage M2a Polarization and A1 Astrocyte Activation

To identify potential regulators and investigate the molecular mechanism of macrophage polarization affecting astrocyte activation from the perspective of non-coding RNA regulation, we isolated mouse bone marrow mononuclear cells (BMMNCs)-induced macrophages toward M1 or M2a polarization. Long non-coding RNA NEAT1 and IL-33 expression levels were significantly upregulated in M2a macrophages; NEAT1 knockdown in M2a macrophages markedly reduced the protein levels of IL-33 and M2a markers, IL-4 and IL-13 concentrations, and the bacterial killing capacity of M2a macrophages. NEAT1 acted as a competing endogenous RNA (ceRNA) to regulate IL-33 expression by sponging miR-224-5p in M2a macrophages; NEAT1 knockdown upregulated miR-224-5p expression, while miR-224-5p inhibition increased the protein content and concentration of IL-33. miR-224-5p inhibition exerted the opposite effects on the protein levels of IL-33 and M2a markers, IL-4 and IL-13 concentrations, and the bacterial killing capacity of M2a macrophages compared to NEAT1 knockdown; the effects of NEAT1 knockdown were significantly reversed by miR-224-5p inhibition. M2a macrophage conditioned medium (CM) significantly suppressed the activation of A1 astrocytes. NEAT1 knockdown M2a macrophage CM led to enhanced A1 astrocyte activation while miR-224-5p-silenced M2a macrophage CM led to a blockade of A1 astrocyte activation; the effects of NEAT1 knockdown M2a macrophage CM on A1 astrocyte activation were significantly reversed by miR-224-5p inhibition in M2a macrophages. The NEAT1/miR-224-5p/IL-33 axis modulates macrophage M2a polarization, therefore affecting A1 astrocyte activation.

miR-224-5p Carried by Human Umbilical Cord Mesenchymal Stem Cells-Derived Exosomes Regulates Autophagy in Breast Cancer Cells via HOXA5

Objective: In this study, we focused on the potential mechanism of miRNAs carried by human umbilical cord mesenchymal stem cells-derived exosomes (hUCMSCs-exo) in breast cancer (BC).

Methods: RT-qPCR was conducted for the expression of miR-224-5p and HOXA5 in tissues and cells. After co-culture of exosomes and MCF-7 or MDA-MB-231 cells, the cell proliferation was observed by MTT and cell colony formation assay, while apoptosis was measured by flow cytometry. In addition, the expression of HOXA5 and autophagy pathway-related proteins LC3-II, Beclin-1 and P62 was detected by western blotting. And immunofluorescence was applied for detection of LC3 spots. The binding of miR-224-5p to HOXA5 was verified by the luciferase reporter gene assay and RNA-binding protein immunoprecipitation assay. Finally, in vivo experiment was performed to investigate the effect of miR-224-5p on BC growth.

Results: MiR-224-5p was up-regulated and HOXA5 was down-regulated in BC tissues and cells. HOXA5 was confirmed to be the target gene of miR-224-5p. MiR-224-5p carried by hUCMSCs-exo was able to promote the proliferation and autophagy of BC cells, while inhibited apoptosis. Bases on xenograft models in nude mice, it was also revealed that miR-224-5p carried by hUCMSCs-exo could regulate autophagy and contribute to the occurrence and development of BC in vivo.

Conclusion: MiR-224-5p carried by hUCMSCs-exo can regulate autophagy via inhibition of HOXA5, thus affecting the proliferation and apoptosis of BC cells.

lncRNA MIR503HG inhibits cell proliferation and promotes apoptosis in TNBC cells via the miR-224-5p/HOXA9 axis

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer. This study investigated the molecular mechanism and influences of MIR503HG, miR-224-5p, and homeobox A9 (HOXA9) on TNBC cell growth and migration. Dual-luciferase reporter gene and RNA immunoprecipitation were performed to examine the regulation of MIR503HG, miR-224-5p, and HOXA9. Cell proliferation, apoptosis, migration, and invasion were evaluated by colony formation, flow cytometry, and Transwell assays. Finally, nude mice were employed to investigate the influence of MIR503HG on TNBC tumor growth. HOXA9 protein levels were detected by immunohistochemical staining. MIR503HG and HOXA9 expression were reduced in TNBC, while miR-224-5p was increased. Overexpression of MIR503HG or HOXA9 reduced the cell migration ability and proliferation and promoted apoptosis, and knockdown of MIR503HG or overexpression of miR-224-5p exhibited the opposite effects. Furthermore, MIR503HG promoted HOXA9 expression by inhibiting miR-224-5p. Overexpression of miR-224-5p reversed the effects of MIR503HG overexpression on TNBC cells, while overexpression of HOXA9 reversed the effect of MIR503HG knockdown. Additionally, an in vivo study proved that MIR503HG inhibited TNBC tumor growth via the miR-224-5p/HOXA9 axis. MIR503HG inhibited cell proliferation and promoted the apoptosis of TNBC cells via the miR-224-5p/HOXA9 axis, which may function as a novel target for the treatment of TNBC.

miR-224-5p-enriched exosomes promote tumorigenesis by directly targeting androgen receptor in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common form of cancer, resulting in cancer-related deaths worldwide. Exosomes, a subclass of extracellular vesicles, are produced and secreted from various types of cells, including cancer cells. Cancer-derived exosomes can deliver nucleic acids, proteins, and lipids to provide a favorable microenvironment that supports tumor growth through enhancing cell proliferation and metastasis. Our results showed that miR-224-5p was upregulated in NSCLC patient tissues and cell lines, with a tumor-promoting phenotype. Meanwhile, exosome-derived miR-224-5p induced cell proliferation and metastasis in NSCLC and human lung cells. Moreover, we characterized the androgen receptor (AR) as a direct target of miR-224-5p. Tumor xenograft assay experiments revealed that overexpression of miR-224-5p drove NSCLC tumor growth via the suppression of AR and the mediation of epithelial-mesenchymal transition (EMT). Collectively, our results suggest that miR-224-5p-enriched exosomes promote tumorigenesis by directly targeting AR in NSCLC, which may provide novel potential therapeutic and preventive targets for NSCLC.

miR-224-5p Contained in Urinary Extracellular Vesicles Regulates PD-L1 Expression by Inhibiting Cyclin D1 in Renal Cell Carcinoma Cells

The abundant miRNAs in urinary extracellular vesicles (EVs) represent ideal reservoirs for biomarker discovery, especially in renal cell carcinoma (RCC). However, the content and biological functions of microRNAs contained in urinary EVs in RCC remain ambiguous. In this study, urinary EVs were isolated and characterized from RCC patients and healthy volunteers. Differentially expressed microRNAs in urinary EVs were screened by small RNA sequencing. The target gene and biological functions of selected microRNAs were investigated through multifaceted methods. Results indicated that miR-224-5p was significantly upregulated in urinary EVs of RCC patients compared to healthy volunteers. The overexpression of miR-224-5p inhibited RCC cell proliferation and induced cell cycle arrest. The gene CCND1 encoding cyclin D1 was identified as a direct target of miR-224-5p via prediction and validation. Moreover, the invasive and metastatic abilities of RCC cells were enhanced by miR-224-5p. Interestingly, miR-224-5p also increased the stability of PD-L1 protein by inhibiting CCND1. This effect could be transmitted via EVs and further promoted the resistance of RCC cells to T cell-dependent toxicity. In summary, urinary EVs containing miR-224-5p were identified as a potential biomarker in RCC. Regulation of PD-L1 protein expression by miR-224-5p through suppressing CCND1 elucidates new roles of miR-224-5p in RCC progression.

Up-regulation of circRNA-0003528 promotes mycobacterium tuberculosis associated macrophage polarization via down-regulating miR-224-5p, miR-324-5p and miR-488-5p and up-regulating CTLA4

Background: In this study, we selected several candidate miRNAs to study their possible relationships with tuberculosis.

Results: The expression of hsa_circ_0003528 was negatively correlated with the expression of miR-224-5p, miR-324-5p, miR-488-5p, miR-587, and miR-668, while the expression of hsa_circ_0003528 was positively correlated with the expression of miR-224-5p, miR-324-5p and miR-488-5p. No evident difference was observed between tuberculosis and healthy control groups in terms of the expression of miR-587 and miR-668.

Conclusion: The findings of this study demonstrated that miR-224-5p, miR-324-5p and miR-488-5p were all ceRNAs of circRNA-0003528 by sponging each other and CTLA4 was found to be a shared target gene of miR-224-5p, miR-324-5p and miR-488-5p. Furthermore, we found that up-regulation of circRNA-0003528 promoted tuberculosis associated macrophage polarization by promoting expression CTLA4, which was mediated by the down-regulation of miR-224-5p, miR-324-5p and miR-488-5p.

Methods: RT-qPCR and Western blot were conducted to observe the expression of hsa_circ_0003528, miRNAs and CTLA4 in different patient and cell groups to establish the potential molecular mechanisms underlying the effect of hsa_circ_0003528 on M1 to M2 macrophage polarization.

Long non-coding RNA LINC00665 promotes melanoma cell growth and migration via regulating the miR-224-5p/VMA21 axis

Melanoma is an aggressive malignant skin tumor endangering the health of patients. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been increasingly reported to be implicated in the carcinogenesis of melanoma. Long intergenic non-coding RNA 00665 (LINC00665) has been found to exert important regulatory roles in some cancers, yet its function in melanoma remains to be investigated. QRT-PCR analysis was conducted to evaluate the relative expression of RNAs. Functional experiments in vitro including colony formation, EdU, wound-healing and transwell assays, as well as in vivo xenograft assays, were utilized to study the role of LINC00665 in melanoma. Mechanical experiments were implemented to probe into the molecular linkage of LINC00665, miR-224-5p and VMA21. LINC00665 was abnormally highly expressed in melanoma cells. Silencing LINC00665 could inhibit the proliferation and migration of melanoma cells. LINC00665 sponged miR-224-5p to upregulate VMA21. VMA21 knockdown exerted similarly interfering effects on above biological processes in melanoma cells. However, VMA21 overexpression abolished the in vitro and in vivo outcomes of LINC00665 silencing. LINC00665 promotes proliferative and migrating abilities of melanoma cells via targeting miR-224-5p/VMA21 axis.

Upregulated miR-224-5p suppresses osteoblast differentiation by increasing the expression of Pai-1 in the lumbar spine of a rat model of congenital kyphoscoliosis

Congenital scoliosis is defined by the presence of structural anatomical malformations that arise from failures of vertebral formation or segmentation before and after birth. The understanding of genetic background and key genes for congenital scoliosis is still poor. We herein report that the excess expression of plasminogen activator inhibitor-1 (Pai-1) induced by the upregulation of miR-224-5p is involved in the pathogenesis of congenital kyphoscoliosis through impaired osteoblast differentiation. We first investigated the variety and progression of abnormalities of the lumbar spines in Ishibashi (IS) rats, a rat model of congenital kyphoscoliosis. The rats had already shown fusion and division of the primary ossification center at postnatal day 4. Over time, the rats showed various abnormalities of the lumbar spine, including the fusion of the annular epiphyseal nucleus. At postnatal day 42, spinal curvature was clearly observed due to the fusion of the vertebral bodies. Using a microRNA array, we found that the expression of miR-224-5p was increased in the lumbar spine of the rats at postnatal day 4. The expression of Pai-1, which is involved in osteoblast differentiation regulated by miR-224-5p, was also increased, while the levels of type I collagen, a marker of osteoblast differentiation, were decreased in the lumbar spine. These results indicate that the aberrant expression of miRNA-224-5p and its target genes is involved in the impaired osteoblast differentiation and may provide a partial molecular explanation for the pathogenesis of congenital scoliosis.

MiR224-5p Inhibitor Restrains Neuronal Apoptosis by Targeting NR4A1 in the Oxygen-Glucose Deprivation (OGD) Model

This study was designed to investigate the molecular mechanism of stroke and to explore the effect of miR-224-5p in hypoxic cortical neurons. Firstly, we established a middle cerebral artery occlusion (MCAO) model with Sprague–Dawley rats. Triphenyltetrazolium chloride (TTC) staining showed the brain infarction of an MCAO rat. Longa scores of rats were significantly increased in 12th, 24th, and 48th hours after MCAO. Then, we found that miR-224-5p was increased after MCAO in rats by qRT-PCR. In order to investigate the effect of miR-224-5p in hypoxic neurons, we established an oxygen-glucose deprivation (OGD) model with cortical neurons. MiR-224-5p was also upregulated in neurons after OGD by qRT-PCR. After transfection of the miR-224-5p inhibitor, the number of neurons in the anti-miR-224-5p group significantly increased (P < 0.01) in comparison to the anti-NC group. Furthermore, Tuj1⁺ (neuronal marker) staining and TUNEL assay (to detect apoptotic cells) were performed in neurons. The survival of neurons in the anti-miR-224-5p group was significantly improved (P < 0.01), while the apoptosis of neurons in the anti-miR-224-5p group was significantly decreased (P < 0.01), when compared with that of the anti-NC group. In addition, we predicted that potential target genes of miR-224-5p were nuclear receptor subfamily 4 group A member 1 (NR4A1), interleukin 1 receptor antagonist (IL1RN), and ring finger protein 38 (RNF38) with bioinformatics databases, such as TargetScan, miRDB, miRmap, and miRanda. The result of qRT-PCR confirmed that NR4A1 was significantly decreased after hypoxic injury (P < 0.01). Meanwhile, luciferase reporter’s assay indicated that NR4A1 was the direct target of miR-224-5p. Compared with the anti-miR-224-5p + siNC group, the number of cortical neurons and the length of the neuron axon in the anti-miR-224-5p + si-NR4A1 group were significantly decreased (P < 0.01), and the number of neuronal apoptosis in the anti-miR-224-5p + si-NR4A1 group was increased (P < 0.01). In conclusion, miR-224-5p played a crucial role in hypoxic neuron injury through NR4A1, which might be an important regulatory mechanism in OGD injury of neurons.

Hsa_circ_0017639 expression promotes gastric cancer proliferation and metastasis by sponging miR-224-5p and upregulating USP3

Gastric cancer (GC) is a common malignant tumor having poor prognosis globally. Circular RNA (circRNA) is a circular endogenous RNA generated by special selective splicing that occurs in various traits. Studies show that hsa_circ_0017639 is abnormally expressed and involved in tumorigenesis. Nevertheless, the hsa_circ_0017639 role in GC is unknown. This study detected hsa_circ_0017639 expression in a GC cell line using RT-qPCR. Subcellular localization of hsa_circ_0017639 was verified via FISH. We assessed correlations amongst miRNA, hsa_circ_0017639 and relative protein levels using luciferase reporter assays and RNA pulldown assays. The data illustrated that in hsa_circ_assays, expression was enhanced in GC cell. Downregulation of hsa_circ_0017639 decreased GC cell proliferation and migration in in vitro and in vivo experiments. RNA pulldown and RT-qPCR analysis verified that hsa_circ_0017639 sponged miR-224-5p. Bioinformatic and luciferase reporter assays validated that miR-224-5p and USP3 were downstream targets of hsa_circ_0017639. Upregulation of USP3 or downregulation of miR-224-5p restored proliferation and migration by MKN-28 and MGC-803 cells after hsa_circ_0017639 silencing. Upregulation of USP3 restored MKN-28 and MGC-803 cell proliferation and migration after overexpression of miR-224-5p. Our collective findings advised that hsa_circ_0017639 takes part in GC progression through regulating the miR-224-5p/USP3 axis, highlighting its potential as an effective GC therapeutic target.

FOXM1-Activated LINC01094 Promotes Clear Cell Renal Cell Carcinoma Development via MicroRNA 224-5p/CHSY1

Clear cell renal cell carcinoma (ccRCC) is regarded as the most aggressive subtype of RCC, with high rates of metastasis and recurrence. An extensive body of studies had proved long noncoding RNAs (lncRNAs) play pivotal parts in the development and evolution of diverse malignant tumors. However, the potential of LINC01094 in ccRCC tumorigenesis is still unexplored. In the present research, with the aid of the TCGA database, we found that LINC01094 was highly expressed in ccRCC tissues. Upregulation of LINC01094 was also confirmed in ccRCC cell lines, and functional experiments delineated that LINC01094 knockdown led to inhibition on ccRCC cell growth and metastasis. Moreover, LINC01094 was activated by FOXM1 at the transcriptional level. Further assay demonstrated that LINC01094 worked as a sponge of microRNA 224-5p (miR-224-5p) and CHSY1 was a miR-224-5p-targeted mRNA. Further, we verified that LINC01094 acted as a competing endogenous RNA in ccRCC to regulate CHSY1 expression via competitively bind to miR-224-5p. Lastly, our results expounded that LINC01094 exerted its tumor-promoting performance in ccRCC development through miR-224-5p/CHSY1 regulatory axis, which shed light on the molecular mechanism underlying LINC01094 in ccRCC and opened a new prospective for the treatment of ccRCC.

CircPCMTD1 Acts as the Sponge of miR-224-5p to Promote Glioma Progression

Glioma is the most common malignant tumor of the central nervous system with high morbidity and mortality. Circular RNAs (circRNAs) are abundant non-coding RNAs, which contribute to tumor progression by competing with other endogenous RNAs such as microRNA (miRNA). MiRNA are a class of small non-coding RNAs, which interrupt the translation of target mRNAs. CircPCMTD1 (hsa-circ-0001801) is a newly discovered circRNA that was found to be significantly upregulated in glioma. However, its function is unclear. In this study, circPCMTD1 upregulation promoted the cell viability, migration and invasion dramatically, while the inhibition of circPCMTD1 led to a significant reduction of tumor growth in vivo. MiRNAs microarray analyses on circPCMTD1 silencing models in U251 and U118MG cells were performed, and the results suggested that circPCMTD1 knockdown could upregulate the expression of miR-224-5p and downregulate the expression of mTOR, one of miR-224-5p targets, in both cell lines. According to the prediction from circular RNA interactome and Targetscan, there was a complementary sequence in circPCMTD1 for miR-224-5p. Dual-luciferase reporter assay demonstrated that circPCMTD1 were targets of miR-224-5p. RIP assay was also performed to further confirm their directly interaction. Overexpression of miR-224-5p inhibited the viability and proliferation, migration, and invasion of U251 and U118MG glioma cells. In conclusion, circPCMTD1 could contribute to the promotion of glioma progression, and it may serve as the sponge of miR-224-5p to exert its function.

miR-224-5p inhibits proliferation, migration, and invasion by targeting PIK3R3/AKT3 in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Accumulating investigations have identified the aberrant expression of miRNAs (microRNAs) in UM, such as miR-181, miR-20a, miR-144, miR-146a. The purpose of this study is to investigate the biological function of miR-224-5p in UM. The expression of miR-224-5p, PIK3R3, and AKT3 in 30 tumor tissues and paired adjacent noncancerous tissues were analyzed using Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell proliferation assay, transwell assay, and wound healing assay were used to measure the effects of miR-224-5p on the motility of UM in vitro. Western blot analysis and luciferase assays were used to detect the expression of PIK3R3 and AKT3 as miR-224-5p downstream targets. The results of Western blot analysis and qRT-PCR assays indicated that the expression of miR-224-5p was lower in UM tissues compared to normal tissue, while the expression of PIK3R3 and AKT3 were simultaneously increased. Upregulation of miR-224-5p significantly inhibited capacities of proliferation, invasion, and migration of OCM-1A cells and decreased expression of PIK3R3 and AKT3. Luciferase assay demonstrated PIK3R3 and AKT3 as downstream targets of miR-224-5p. Moreover, upregulating PIK3R3 and AKT3 restrained miR-224-5p-induced inhibition of the motility of OCM-1A cells. Thus, our study proved that miR-224-5p was involved in proliferation, invasion, and migration of UM cells via regulation the expression of PIK3R3 and AKT3. And the results also established a miR-224-5p/PIK3R3/PI3K/AKT axis in the regulation of UM progression, providing an experimental basis for further exploring the miR-224-5p as a therapeutic and diagnosis target for patients with UM.

MiRNA-224-5p inhibits autophagy in breast cancer cells via targeting Smad4

BACKGROUND/AIMS

Autophagy is known as a protective intracellular procedure, which can be regulated by several factors. MiRNA has been suggested as a potential element to mediate autophagy pathway in carcinomas. Our study was aim to investigate the role of autophagy in breast cancer cells and identify the involved molecular mechanism METHODS: The expression of LC3I/II, SQSTM1 and Smad4 were detected by western blot. The mRNA level were quantified by real-time PCR. MDC staining was used to directly visualize autophagosome formation. Target Scan 7.2 was used to predict biological targets of miR-224-5p RESULTS: MiR-224 -5p expression was upregulated in metastatic breast cancer and non-metastatic breast cancer cells compare with control. Moreover, miR-224-5p inhibition enhanced cellular autophagy levels in breast cancer cells. MiR-224-5p could suppress Smad4 expression in MDA-MB-231 cells, which indicated that Smad4 was identified as a target of miR-224-5p in breast cancer cells with high metastatic potential CONCLUSIONS: Our study revealed that miR-224-5p inhibited autophagy by targeting Smad4 in MDA-MB-231 cells. The results indicated that miR-224-5p/Smad4 regulating autophagy might be a novel regulatory network contributing to metastasis of breast cancer. MiR-224-5p and Smad4 is involved in breast tumorigenesis, which is possibly a novel target for breast cancer therapy.