Association of 3'UTR variations of EGFR and KRAS oncogenes with clinical parameters in lung cancer tumours.

BACGROUND INFORMATION: Lung cancer is one of the leading types of cancer deaths worldwide, with approximately 2 million people diagnosed with lung cancer each year. In this study, we aimed to determine the exonic and 3'UTR sequences of EGFR, PIK3CA and KRAS genes in 39 sporadic lung cancer tumors and to reveal the changes in the miRNA binding profile of tumors with somatic variation in the 3'UTR region and to examine the relationship of these changes with clinical parameters. RESULTS: A statistically significant correlation was found between the presence of miRNA that could not bind to the 3'UTR region due to variation in at least one of the EGFR or KRAS genes and the presence of metastasis in the tumor. At the same time, Kaplan-Meier analysis between those with and without alterations in the miRNA profile due to somatic variation in the 3'UTR region showed that survival was lower in those with miRNA alterations and this was statistically significant. CONCLUSIONS: In our study, it was shown that variations in the 3'UTR regions of EGFR and KRAS oncogenes may cause increased expression of these oncogenes by preventing the binding of miRNAs, and it was suggested that this may be related to metastasis, survival and drug resistance mechanism. SIGNIFICANCE: In this study, we show that hsa-miR-124-3p, hsa-miR-506-3p, hsa-miR-1290 and hsa-miR-6514-3p are particularly prominent in lung carcinoma in relation to these biological pathways and the roles that variations in the 3'UTR regions of oncogenes may play in the carcinogenesis process.

Hsa_circRNA_007630 knockdown delays colon cancer progression by modulation of ferroptosis via miR-506-3p/AURKA axis.

Colon cancer contributes to high mortality rates internationally that has seriously endangered human health. Aurora kinase A (AURKA) served as a key molecule in colon cancer. However, its role of AURKA on regulating ferroptosis in colon cancer and their possible interactions with miRNAs and circRNAs remain still elusive. Comprehensive bioinformatics analysis after RNA-sequencing was conducted to determine the differentially expressed genes (DEGs), ferroptosis-related DEGs and hub genes. The direct relationship between miR-506-3p and hsa_circRNA_007630 or AURKA was predicted, then verified by dual luciferase reporter and quantitative real-time polymerase chain reaction. The rescue experiments were conducted by cotransfection with si-hsa_circRNA_007630, miR-506-3p inhibitor or pcDNA-AURKA in HT29 cells. Erastin was used to induce ferroptosis in HT29 cells and validated by detecting levels of intracellular Fe2+, lipid reactive oxygen species, glutathione, malondialdehyde and ferroptosis markers expression. We screened a total of 331 DEGs, 26 ferroptosis-related genes, among which 3 hub genes were identified through PPI network analysis. Therein, AURKA expression was elevated in colon cancer cells. Moreover, AURKA was targeted by miR-506-3p, and hsa_circRNA_007630 operated as miR-506-3p sponge. The effect of hsa_circRNA_007630 depletion on the inhibiting malignant phenotypes of HT29 cells was rescued by inhibition of miR-506-3p or AURKA overexpression. Additionally, AURKA reduced erastin-induced ferroptosis in HT29 cells. Depletion of circRNA_007630 exerts as a suppressive role in colon cancer through a novel miR-506-3p/AURKA pathway related to ferroptosis, and might become a novel marker for colon cancer.

CircNRCAM up-regulates NRCAM to promote papillary thyroid carcinoma progression.

PURPOSE: Papillary Thyroid Carcinoma (PTC) is the most prevalent subtype of Thyroid Carcinoma (THCA), a type of malignancy in the endocrine system. According to prior studies, Neural Cell Adhesion Molecule (NRCAM) has been found to be up-regulated in PTC and stimulates the proliferation and migration of PTC cells. However, the specific mechanism of NRCAM in PTC cells is not yet fully understood. Consequently, this study aimed to investigate the underlying mechanism of NRCAM in PTC cells, the findings of which could provide new insights for the development of potential treatment targets for PTC. METHODS AND RESULTS: Bioinformatics tools were utilized and a series of experiments were conducted, including Western blot, colony formation, and dual-luciferase reporter assays. The data collected indicated that NRCAM was overexpressed in THCA tissues and PTC cells. Circular RNA NRCAM (circNRCAM) was found to be highly expressed in PTC cells and to positively regulate NRCAM expression. Through loss-of-function assays, both circNRCAM and NRCAM were shown to promote the proliferation, invasion, and migration of PTC cells. Mechanistically, this study confirmed that precursor microRNA-506 (pre-miR-506) could bind with m6A demethylase AlkB Homolog 5 (ALKBH5), leading to its m6A demethylation. It was also discovered that circNRCAM could competitively bind to ALKBH5, which restrained miR-506-3p expression and promoted NRCAM expression. CONCLUSION: In summary, circNRCAM could up-regulate NRCAM by down-regulating miR-506-3p, thereby enhancing the biological behaviors of PTC cells.

Botulinum Toxin Type A Alleviates Androgenetic Alopecia by Inhibiting Apoptosis of Dermal Papilla Cells via Targeting circ_0135062/miR-506-3p/Bax Axis.

Botulinum toxin type A (BTXA) has the potential to treat androgenetic alopecia (AGA); however, its impact on the apoptosis of dermal papillary cells (DPCs) is not yet fully understood. Noncoding RNAs play a crucial role in AGA. In this study, we investigated the potential mechanism by which BTXA alleviates apoptosis induced by dihydrotestosterone (DHT) in DPCs. We assessed the mRNA levels of circ_0135062, miR-506-3p, and Bax using qRT-PCR. Binding interactions were analyzed using RNA pulldown and dual-luciferase assays. Cell viability was determined using a cell counting kit-8 assay, and cell apoptosis was assessed using flow cytometry, TUNEL assays, and western blotting. Our findings revealed that BTXA inhibited the apoptosis of DPCs treated with DHT. Moreover, circ_0135062 overexpression counteracted the protective effect of BTXA on DHT-treated DPCs. MiR-506-3p was found to interact with Bax and inhibit apoptosis in DPCs by suppressing Bax expression in response to DHT-induced damage. Furthermore, circ_0135062 acted as a sponge for miR-506-3p, thereby inhibiting the targeting of Bax expression by miR-506-3p. In conclusion, BTXA exhibited an antiapoptotic effect on DHT-induced DPC injury via the circ_0135062/miR-506-3p/Bax axis.Level of Evidence II This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Stable Dual miR-143 and miR-506 Upregulation Inhibits Proliferation and Cell Cycle Progression.

The mainstays of lung cancer pathogenesis are cell cycle progression dysregulation, impaired apoptosis, and unregulated cell proliferation. While individual microRNA (miR) targeting or delivering is a promising approach that has been extensively studied, combination of miR targeting can enhance therapeutic efficacy and overcome limitations present in individual miR regulations. We previously reported on the use of a miR-143 and miR-506 combination via transient transfections against lung cancer. In this study, we evaluated the effect of miR-143 and miR-506 under stable deregulations in A549 lung cancer cells. We used lentiviral transductions to either up- or downregulate the two miRs individually or in combination. The cells were sorted and analyzed for miR deregulation via qPCR. We determined the miR deregulations' effects on the cell cycle, cell proliferation, cancer cell morphology, and cell motility. Compared to the individual miR deregulations, the combined miR upregulation demonstrated a miR-expression-dependent G2 cell cycle arrest and a significant increase in the cell doubling time, whereas the miR-143/506 dual downregulation demonstrated increased cellular motility. Furthermore, the individual miR-143 and miR-506 up- and downregulations exhibited cellular responses lacking an apparent miR-expression-dependent response in the respective analyses. Our work here indicates that, unlike the individual miR upregulations, the combinatorial miR treatment remained advantageous, even under prolonged miR upregulation. Finally, our findings demonstrate potential advantages of miR combinations vs. individual miR treatments.

Hepatic stellate cell-released CXCL1 aggravates HCC malignant behaviors through the MIR4435-2HG/miR-506-3p/TGFB1 axis.

Hepatic stellate cell (HSC) activation is a critical event in the development of hepatic fibrosis and hepatocellular carcinoma (HCC). By the release of soluble cytokines, chemokines, and chemotaxis, HSCs affect HCC cell phenotypes through a complex tumor microenvironment. In this study, weighted gene co-expression network analysis (WGCNA) was used to identify the TGF-ß signaling pathway as a key signaling pathway in Hep3B cells cultured in HSC conditioned medium. MIR4435-2HG is a hub lncRNA associated with the TGF-ß signaling pathway and HSC activation. HSC-condition medium (CM) culture induced HCC cell malignant behaviors, which were partially reversed by MIR4435-2HG silencing. miR-506-3p directly bound to MIR4435-2HG and the 3'UTR of TGFB1. Similarly, overexpression of miR-506-3p also attenuated HSC-CM-induced malignant behavior of HCC cells. In HSC-CM cultured HCC cells, the effects of MIR4435-2HG knockdown on TGFB1 expression and HCC cell phenotypes were partially reversed by miR-506-3p inhibition. HSCs affected HCC cell phenotypes by releasing CXCL1. In an orthotopic xenotransplanted tumor model of HCC cells plus HSCs in mice, CXCR2 knockdown in HCC cells significantly inhibited tumorigenesis, which was partially reversed by MIR4435-2HG overexpression in HCC cells. In HCC tissue samples, the levels of CXCL1, TGF-ß1, and MIR4435-2HG were upregulated, while miR-506-3p expression was downregulated. In conclusion, HSC-released CXCL1 aggravated HCC cell malignant behaviors through the MIR4435-2HG/miR-506-3p/TGFB1 axis. In addition to CXCL1, the MIR4435-2HG/miR-506-3p/TGFB1 axis might also be the underlying target for HCC therapy.

miR-506-3p Relieves Neuropathic Pain following Brachial Plexus Avulsion via Mitigating Microglial Activation through Targeting the CCL2-CCR2 Axis.

Neuroinflammation results in neuropathic pain (NP) following brachial plexus avulsion (BPA). This research was designed for investigating the function of miR-506-3p in BPA-induced NP. A total brachial plexus root avulsion model was produced in adult rats as well as IL-1ß-treated motoneuron-like NSC-34 cells and the LPS-treated microglia cell line BV2 for in vivo and in vitro experiments, respectively. RT-PCR and Western blot were performed to detect the profiles of miR-506-3p, CCL2 and CCR2, NF-κB, FOXO3a, TNF-α, IL-1ß, and IL-6 in cells or the spinal cord close to the tBPI lesion. Neuronal apoptosis was evaluated by immunohistochemistry in vivo. CCK8, TUNEL staining, and the lactic dehydrogenase kit were adopted for the evaluation of neuronal viability or damage in vitro. RNA immunoprecipitation and dual luciferase reporter gene assays analyzed the targeted association between miR-506-3p and CCL2. As shown by the data, miR-506-3p was vigorously less expressed, while CCL2-CCR2, NF-κB TNF-α, IL-1ß, and IL-6 were upregulated in the spinal cord with tBPI. Overexpression of miR-506-3p attenuated neuronal apoptosis and microglial inflammation. Mechanistically, CCL2 was a downstream target of miR-506-3p. Upregulating miR-506-3p dampened CCL2-CCR2 and NF-κB activation in the spinal cord and microglia. miR-506-3p had neuroprotective and inflammation-fighting functions in the tBPI rat model via CCL2/CCR2/NF-κB axis.

LINC00543 promotes colorectal cancer metastasis by driving EMT and inducing the M2 polarization of tumor associated macrophages.

BACKGROUND: The interaction between the tumor-microenvironment (TME) and the cancer cells has emerged as a key player in colorectal cancer (CRC) metastasis. A small proportion of CRC cells which undergo epithelial-mesenchymal transition (EMT) facilitate the reshaping of the TME by regulating various cellular ingredients. METHODS: Immunohistochemical analysis, RNA immunoprecipitation (RIP), RNA Antisense Purification (RAP), dual luciferase assays were conducted to investigate the biological function and regulation of LINC00543 in CRC. A series in vitro and in vivo experiments were used to clarify the role of LINC00543 in CRC metastasis. RESULTS: Here we found that the long non-coding RNA LINC00543, was overexpressed in colorectal cancer tissues, which correlated with advanced TNM stage and poorer prognosis of CRC patients. The overexpression of LINC00543 promoted tumorigenesis and metastasis of CRC cells by enhancing EMT and remodeling the TME. Mechanistically, LINC00543 blocked the transport of pre-miR-506-3p across the nuclear-cytoplasmic transporter XPO5, thereby reducing the production of mature miR-506-3p, resulting in the increase in the expression of FOXQ1 and induction of EMT. In addition, upregulation of FOXQ1 induced the expression of CCL2 that accelerated the recruitment of macrophages and their M2 polarization. CONCLUSIONS: Our study showed that LINC00543 enhanced EMT of CRC cells through the pre-miR-506-3p/FOXQ1 axis. This resulted in the upregulation of CCL2, leading to macrophages recruitment and M2 polarization, and ultimately stimulating the progression of CRC.

MiR-506 targets polypyrimidine tract-binding protein 1 to inhibit airway inflammatory response and remodeling via mediating Wnt/ß-catenin signaling pathway.

BACKGROUND: Airway remodeling, which contributes to the clinical course of childhood asthma, occurs due to airway inflammation and is featured by anomalous biological behaviors of airway smooth muscle cells (ASMCs). microRNA (miRNA) plays an essential role in the etiopathogenesis of asthma. OBJECTIVE: This research was aimed to characterize miR-506 in asthma and uncover potential regulatory machinery. MATERIAL AND METHODS: The asthmatic cell model was established by treating ASMCs with transforming growth factor-beta1 (TGF-ß1) and assessed by the levels of interleukin (IL)-1ß and interferon gamma (IFN-γ). Using real-time quantitative polymerase chain reaction, mRNA expression of miR-506 and polypyrimidine tract-binding protein 1 (PTBP1) was measured. Cell counting kit-8 and Transwell migration tests were used for estimating the capacity of ASMCs to proliferate and migrate. Luciferase reporter assay was used to corroborate whether miR-506 was directly bound to PTBP1. Expression of PTBP1, collagen I and III, and essential proteins of the wingless-related integration (Wnt)/ß-catenin pathway (ß-catenin, c-MYC and cyclin D1) was accomplished by Western blot analysis. The involvement of Wnt/ß-catenin signaling in asthma was confirmed by Wnt signaling pathway inhibitor (IWR-1). RESULTS: miR-506 was poorly expressed in asthmatic tissues and cell model. Functionally, overexpression of miR-506 reduced aberrant proliferation, migration, inflammation and collagen deposition of ASMCs triggered by TGF-ß1. Mechanically, miR-506 directly targeted the 3' untranslated region (3-UTR) of PTBP1 and had a negative regulation on PTBP1 expression. Moreover, overexpression of miR-506 suppressed the induction of Wnt/ß-catenin pathway. The administration of IWR-1 further validated negative correlation between miR-506 and the Wnt/ß-catenin pathway in asthma. CONCLUSION: Our data indicated that targeting miR-506/PTBP1/Wnt/ß-catenin axis might point in a helpful direction for treating asthma in children.

Development of Shortened miR-506-3p Mimics Exhibiting Strong Differentiation-Inducing Activity in Neuroblastoma Cells.

microRNA mimics are synthetic RNA molecules that imitate the mature miRNA duplexes and their functions. These mimics have shown promise in treating cancers. Nucleotide chemical modifications of microRNA mimics have been investigated and have improved the stability of miRNA mimics. However, the potential therapeutic benefit of mimic analogs based on sequence modifications has not been explored. miR-506-3p was identified as a differentiation-inducing microRNA in neuroblastoma cells, suggesting the potential of applying the miR-506-3p mimic in neuroblastoma differentiation therapy. In this study, we explored the possibility of developing shortened miR-506-3p analogs that can maintain differentiation-inducing activities comparable to the wild-type miR-506-3p mimic. We found that deleting up to two nucleotides at either the 3' end or within the middle region of the miR-506-3p sequence fully maintained the differentiation-inducing activity when compared to the wild-type mimic. Deleting up to four nucleotides from the 3' end or deleting three nucleotides in the middle positions diminished the differentiation-inducing activity, but the analogs still maintained differentiation-inducing activities that were significantly higher than the negative control oligo. The shortened analog designs potentially benefit patients from two perspectives: (1) the reduced cost of manufacturing shortened analogs, and (2) the reduced non-specific toxicity due to their smaller molecular sizes.

Inhibition of CD4 + T cells by fanchinoline via miR506-3p/NFATc1 in Sjögren's syndrome.

The hyperproliferation and hyperactivation of CD4 + T cells in salivary gland tissues are hallmarks of Sjögren's syndrome (SS). Fangchinoline (Fan) is extracted from the root of Stephania tetrandra Moore, which is used for treating rheumatic diseases in many studies. This study aimed to identify the mechanism underlying the inhibition of CD4 + T cells by Fan in the SS model NOD/ShiLtj mice. In vivo, Fan alleviated the dry mouth and lymphocyte infiltration in the salivary gland tissues of the NOD/ShiLtj mice and inhibited the number of CD4 + T cells in the infiltrating focus. In vitro, Fan's inhibitory effect on the proliferation of mouse primary CD4 + T cells was verified by CFSE and EdU tests. Furthermore, qRT-PCR and WB analysis confirmed that Fan could inhibit the expression of NFATc1 (Nuclear factor of activated T-cells, cytoplasmic 1) by upregulating miR-506-3p. Dual luciferase reporter gene assay suggested that miR-506-3p interacted with NFATc1. CFSE and EdU tests showed that Fan could inhibit the proliferation of CD4 + T cells through miR-506-3p/NFATc1. The key role of NFATc1 in the activation of CD4 + T cells and the high expression of NFATc1 in samples from SS patients suggested that NFATc1 might become a therapeutic target for SS. In vivo, 11R-VIVIT (NFATc1 inhibitor) alleviated SS-like symptoms. This study not only explained the new mechanism of Fan inhibiting proliferation of CD4 + T cells and alleviating SS-like symptoms but also provided NFATc1 as a potential target for the subsequent research and treatment of SS.

Exosomes derived from myeloid-derived suppressor cells facilitate castration-resistant prostate cancer progression via S100A9/circMID1/miR-506-3p/MID1.

BACKGROUND: Castration-resistant prostate cancer (CRPC) is a major cause of recurrence and mortality among prostate cancer (PCa) patients. Myeloid-derived suppressor cells (MDSCs) regulate castration resistance in PCa. Previously, it was shown that intercellular communication was efficiently mediated by exosomes (Exos), but the role and the mechanism of MDSC-derived Exos in CRPC progression was unclear. METHODS: In this study, the circRNA expression profiles in PC3 cells treated with MDSC-Exo and control cells were investigated using a circRNA microarray. RESULTS: The data showed that circMID1 (hsa_circ_0007718) expression was elevated in PC3 cells treated with MDSC-Exo. Moreover, high circMID1 expression was found in PCa compared with benign prostatic hyperplasia (BPH) tissues and in CRPC patients compared with hormone sensitive prostate cancer (HSPC) patients. Further studies showed that MDSC-Exo accelerated PCa cell proliferation, migration, and invasion, while circMID1 deficiency inhibited MDSC-Exo-regulated CRPC progression in vitro and in vivo. Mechanistically, MDSC-derived exosomal S100A9 increased circMID1 expression to sponge miR-506-3p, leading to increased MID1 expression and accelerated tumor progression. CONCLUSION: Together, our results showed that a S100A9/circMID1/miR-506-3p/MID1 axis existed in MDSC-Exo-regulated CRPC progression, which provided novel insights into MDSC-Exo regulatory mechanisms in CRPC progression.

LncRNA LINC01410 Induced by MYC Accelerates Glioma Progression via Sponging miR-506-3p and Modulating NOTCH2 Expression to Motivate Notch Signaling Pathway.

Glioma is a common invasive cancer with unfavorable prognosis in patients. Long non-coding RNAs have been reported to participate in modulating diverse cellular processes. Here, we focused on exploring the role of long intergenic non-protein coding RNA 1410 (LINC01410) in glioma and its underlying mechanism. The expression levels and protein levels of genes were analyzed by quantitative real-time PCR (RT-qPCR) analysis and western blot. Loss-of-function assays were performed to assess the function of LINC01410 in glioma cells. The interactions among MYC, LINC01410, microRNA-506-3p (miR-506-3p) and notch receptor 2 (NOTCH2) were validated through Chromatin immunoprecipitation (ChIP), RNA Binding Protein immunoprecipitation (RIP), RNA pull-down and luciferase reporter assays. Our data supported that LINC01410 was up-regulated in glioma cells. Bioinformatics predictions and the integrated experiments identified that MYC activated LINC01410 transcription and LINC01410 promoted the levels of NOTCH2 through sponging miR-506-3p and further motivated Notch signaling pathway. Rescue assays validated that LINC01410 exerted its influential functions on glioma cell proliferation and apoptosis via enhancing NOTCH2 expression. Our studies identified that LINC01410 accelerates the progression of glioma through acting as a ceRNA for miR-506-3p and elevating NOTCH2 expression to further activate the Notch signaling pathway, which indicated that LINC01410 might act as a novel regulator of glioma progression.

PCGEM1 promotes proliferation, migration and invasion in prostate cancer by sponging miR-506 to upregulate TRIAP1.

BACKGROUND: The important role of long noncoding RNAs (lncRNAs) in cancer has been demonstrated in many studies. Prostate cancer gene expression marker 1 (PCGEM1) is a lncRNA specifically expressed within the prostate and overexpressed in many cancer cells. Numerous studies have shown that PCGEM1 promotes cell proliferation, invasion and migration. However, the specific mechanism of PCGEM1 within prostate cancer (PCa) has not been elucidated. MicroRNA-506-3p (miR-506-3p) is a noncoding RNA, and studies have indicated that miR-506-3p is downregulated in prostate cancer cell lines and functions as a tumor suppressor. METHODS: The TCGA (GEPIA) database ( http://gepia.cancer-pku.cn/ ) was employed to measure PCGEM1 levels in PCa. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the PCGEM1 gene level. CCK-8 (Cell Counting Kit-8) and colony formation assays were used to detect cell proliferation, and Transwell assays were applied to assess cell invasion and migration. The interacting ability of miR-506-3p with PCGEM1 or TRIAP1 was validated through a dual-luciferase reporter assay. TRIAP1 protein expression was detected by Western blotting. RESULTS: PCGEM1 expression was increased in PCa tissues and cells. In PCa tissues, High PCGEM1 expression was associated with high Gleason score, distant metastasis and extracapsular extension. In addition, PCGEM1 knockdown inhibited PCa cell (C4-2B and PC-3) proliferation, invasion and migration. miR-506-3p may interact with PCGEM1 or TRIAP1, and the suppressive effect of PCGEM1 knockdown was reversed when TRIAP1 or a miR-506-3p inhibitor was cotransfected. CONCLUSION: PCGEM1 expression increased in PCa cells and tissues, enhancing PCa cell proliferation, migration and invasion by sponging miR-506 to upregulate TRIAP1.

CircATL2 enhances paclitaxel resistance of ovarian cancer via impacting miR-506-3p/NFIB axis.

Circular RNAs (circRNAs) play vital regulatory roles in the development of ovarian cancer (OC). However, the functions of circRNA Atlastin GTPase 2 (circATL2) in paclitaxel (PTX) resistance of OC are still unclear. As a result, circATL2 was upregulated in PTX-resistant OC tissues and cells. CircATL2 knockdown reduced IC50 of PTX, inhibited colony formation ability and promoted cell cycle arrest and apoptosis in PTX-resistant OC cells. Silencing of circATL2 restrained PTX resistance in vivo. Furthermore, miR-506-3p could be targeted by circATL2 and miR-506-3p inhibition reversed the impacts of circATL2 knockdown on PTX resistance and cell progression in PTX-resistant OC cells. NFIB was identified as the target of miR-506-3p. MiR-506-3p overexpression suppressed PTX resistance and malignant behaviors of PTX-resistant OC cells, with NFIB elevation rescued the impacts. To summarize, circATL2 promoted the resistance of OC to PTX by sponging miR-506-3p to upregulate NFIB expression, providing a new sight in chemoresistance of OC.

miR-506-loaded gelatin nanospheres target PENK and inactivate the ERK/Fos signaling pathway to suppress triple-negative breast cancer aggressiveness.

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Some microRNAs (miRNAs) were abnormally expressed in TNBC, and they are closely related to the occurrence and progression of TNBC. Here, we found that miR-506 was significantly downregulated in TNBC and relatively lower miR-506 expression predicted a poorer prognosis. Moreover, we found that miR-506 could inhibit MDA-MB-231 cell viability, colony formation, migration, and invasion, and suppress the ERK/Fos oncogenic signaling pathway through upregulating its direct target protein proenkephalin (PENK). Therefore, miR-506 was proposed as a nucleic acid drug for TNBC therapy. However, miRNA is unstable in vivo, which limiting its application as a therapeutic drug via conventional oral or injected therapies. Here, a gelatin nanosphere (GN) delivery system was applied for the first time to load exogenous miRNA. Exogenous miR-506 mimic was loaded on GNs and injected into the in situ TNBC animal model, and the miR-506 could achieve sustained and controlled release. The results confirmed that overexpression of miR-506 and PENK in vivo through loading on GNs inhibited in situ triple-negative breast tumor growth and metastasis significantly in the xenograft model. Moreover, we indicated that the ERK/Fos signaling pathway was intensively inactivated after overexpression of miR-506 and PENK both in vitro and in vivo, which was further validated by the ERK1/2-specific inhibitor SCH772984. In conclusion, this study demonstrates that miR-506-loaded GNs have great potential in anti-TNBC aggressiveness therapy.

MicroRNA-506 modulates insulin resistance in human adipocytes by targeting S6K1 and altering the IRS1/PI3K/AKT insulin signaling pathway.

The incidence of obesity has increased rapidly, becoming a worldwide public health issue that involves insulin resistance. A growing number of recent studies have demonstrated that microRNAs play a significant role in controlling the insulin signaling network. For example, miR-506-3p expression has been demonstrated to correlate with insulin sensitivity; however, the underlying mechanism remains unknown. In this study, we found that miR-506-3p enhanced glucose uptake by 2-deoxy-D-glucose uptake assays and regulated the protein expression of key genes involved in the PI3K/AKT insulin signaling pathway including IRS1, PI3K, AKT, and GlUT4. We next predicted ribosomal protein S6 kinase B1 (S6K1) to be a candidate target of miR-506-3p by bioinformatics analysis and confirmed using dual-luciferase assays that miR-506-3p regulated S6K1 expression by binding to its 3'-UTR. Moreover, modulating S6K1 expression counteracted the effects of miR-506-3p on glucose uptake and PI3K/AKT pathway activation. In conclusion, miR-506-3p altered IR in adipocytes by regulating S6K1-mediated PI3K/AKT pathway activation. Taken together, these findings provide novel insights and potential targets for IR therapy.

miR-124-3p combined with miR-506-3p delay hepatic carcinogenesis via modulating sirtuin 1.

OBJECTIVE: Our study aimed at exploring whether miR-124-3p and miR-506-3p collaboratively modulated sirtuin 1 (SIRT1) protein expression in liver cancer. Materials and methods: In this study, cell viability, migration and invasion were assessed using CCK8 and transwell assays, respectively. Immunohistochemical (IHC) staining and immunoblotting analysis were performed to evaluate SIRT1 protein expression levels in tissue specimens and cell lines. Moreover, the nude-mouse transplanted tumour model was used to assess liver cancer cell growth in vivo. Results: Our results showed that SIRT1 protein levels were significantly up-regulated in liver cancer tissues and cancerous cell lines. Conversely, miR-124-3p and miR-506-3p were down-regulated in liver cancer tissues and cell lines. The protein expression of SIRT1 was significantly declined in HepG2 and SMMC7721 cells after transfection with miR-124-3p or miR-506-3p mimics. miR-124-3p and miR-506-3p collaboratively caused a marked inhibition of liver cancer cell growth, migration and invasion, while the phenomena were neutralized by overexpression of SIRT1. In vivo experimental measurements also revealed that miR-124-3p and miR-506-3p synergistically inhibited SIRT1 protein expression and tumour growth in the nude-mouse transplanted tumour model. Conclusion: It was observed that miR-124-3p and miR-506-3p could cooperatively retard liver cancer cell growth via co-inhibiting SIRT1 protein expression.

MiR-506-3p Promotes the Proliferation and Migration of Vascular Smooth Muscle Cells via Targeting KLF4.

BACKGROUND: The dysregulation of proliferation and migration of vascular smooth muscle cells (VSMCs) is one of the major causes of atherosclerosis (AS). Accumulating studies confirm that Kruppel-like factor 4 (KLF4) can regulate the proliferation and differentiation of VSMCs through multiple signaling pathways. However, the mechanism of KLF4 dysregulation remains unknown. METHODS: Apolipoprotein E-knockout (ApoE-/-) mice and human VSMCs were used to establish AS animal model and cell model, respectively. qRT-PCR was employed to determine the expressions of miR-506-3p and KLF4. Cell Counting Kit -8, Transwell, TUNEL assays, and flow cytometry were performed to measure the proliferation, migration, and apoptosis of VSMCs. The upstream miRNAs of KLF4 were predicted by microT, miRanda, miRmap, and TargetScan databases. The interaction between KLF4 and miR-506-3p was confirmed using qRT-PCR, Western blot, and luciferase reporter gene assay. RESULTS: KLF4 expression was significantly decreased in the VSMCs of ApoE-/- mice fed with high-fat diet and in human VSMCs treated with oxidized low-density lipoprotein in time-dependent and dose-dependent manners. The transfection of miR-506-3p mimics or KLF4 shRNA promoted the proliferation and migration of VSMCs but inhibited the apoptosis while miR-506-3p inhibitors and pcDNA3.1-KLF4 exerted opposite effects. Additionally, KLF4 was confirmed as a target gene of miR-506-3p and could be negatively regulated by miR-506-3p. CONCLUSION: MiR-506-3p can promote the proliferation and migration of VSMCs via targeting KLF4, which can probably contribute to the pathogenesis of AS.

Hsa_circ_0016788 regulates hepatocellular carcinoma progression via miR-506-3p/poly-adenosine diphosphate-ribose polymerase.

BACKGROUND AND AIM: Hepatocellular carcinoma (HCC) is a common malignant tumor worldwide. Recent researches have shown that circular RNAs (circRNAs) could affect the progress of HCC, but the mechanism is still indistinct. In this work, we explored the roles of circRNA_0016788 in HCC. METHODS: The levels of hsa_circ_0016788, microRNA-506-3p (miR-506-3p), and mRNA of poly-adenosine diphosphate-ribose polymerase, member 14 (PARP14) were detected by quantitative real-time reverse transcription-polymerase chain reaction in HCC tissues. Meanwhile, the level of PARP14 was quantified by Western blot analysis. Besides, the cell functions were examined by commercial kit, Cell Counting Kit-8 assay, EdU assay, colony formation assay, flow cytometry assay, Western blot, and transwell assay. Furthermore, the interplay between miR-506-3p and hsa_circ_0016788 or PARP14 was detected by dual-luciferase reporter assay. Eventually, the in vivo experiments were applied to measure the role of hsa_circ_0016788. RESULTS: The levels of hsa_circ_0016788 and PARP14 were upregulated, and the miR-506-3p level was decreased in HCC tissues in contrast to that in normal tissues. For functional analysis, hsa_circ_0016788 deficiency inhibited cell glycolysis metabolism, cell vitality, cell proliferation, colony formation, and invasion in HCC cells whereas promoted cell apoptosis. Moreover, miR-506-3p was confirmed to repress the progression of HCC cells by suppressing PARP14. In mechanism, hsa_circ_0016788 acted as a miR-506-3p sponge to regulate the level of PARP14. In addition, hsa_circ_0016788 knockdown also inhibited tumor growth in vivo. CONCLUSION: Hsa_circ_0016788 facilitates the development of HCC through increasing PARP14 expression by regulating miR-506-3p, which also offered an underlying targeted therapy for HCC treatment.