Bone Marrow Mesenchymal Stem Cell-derived Exosomal microRNA- 99b-5p Promotes Cell Growth of High Glucose-treated Human Umbilical Vein Endothelial Cells by Modulating THAP Domain Containing 2 Expression

INTRODUCTION

Bone marrow mesenchymal stem cell-derived exosomes (BMSC-exos) may function as novel candidates for treating diabetic wounds due to their ability to promote angiogenesis.

MATERIALS AND METHODS

This study investigated the effects of BMSC-exos on the growth and metastasis of human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG). The exosomes were separated from BMSCs and identified. The cell phenotype was detected by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and 5-ethynyl-2'-deoxyuridine, wound healing, and transwell assays, while the number of tubes was measured via tube formation assay.

RESULT

The RNA and protein expression levels were studied using reverse transcription-quantitative polymerase chain reaction and western blotting, whereas integration of microRNA-99b-5p (miR-99b-5p) with THAP domain containing 2 (THAP2) was confirmed via dual-luciferase reporter and RNA pull-down assays. Results of transmission electron microscopy, nanoparticle tracking analysis, and laser scanning confocal microscopy revealed that exosomes were successfully separated from BMSCs and endocytosed into the cytoplasm by HUVECs. Similarly, BMSC-exos were found to promote the growth of HG-treated HUVECs, while their growth was inhibited by suppressing miR-99b-5p. THAP2 was found to bind to miR-99b-5p, where THAP2 inhibition reversed the miR-99b-5p-induced effects on cell growth, migration, and tube numbers.

CONCLUSION

In conclusion, miR-99b-5p in BMSC-exo protects HUVECs by negatively regulating THAP2 expression.

Exosomal miR-99b-5p Secreted from Mesenchymal Stem Cells Can Retard the Progression of Colorectal Cancer by Targeting FGFR3

Human bone marrow mesenchymal stem cells (BMSCs) are efficient mass producers of exosomes that can potentially be utilized for delivery of miRNAs in cancer therapy. The current study aimed to assess the role of MSC-exosomal miR-99b-5p during the development of colorectal cancer (CRC). The potential value of using plasma levels of exosomal miR-99b-5p for predicting the liver metastasis of colorectal cancer was also assessed. In this study, we found that overexpression of fibroblast growth factor receptor 3 (FGFR3) was associated with tumor progression in CRC and FGFR3 was the target gene of miR-99b-5p, which was down-regulated in CRC tissues. Furthermore, we observed that elevated miR-99b-5p inhibited CRC cell proliferation, invasion and migration, while reduced levels had the opposite effect on CRC cells. Moreover, exosomal miR-99b-5p delivered by BMSCs was able to limit the proliferation, invasion and migration of CRC cells in vitro, as well as suppressing tumor growth in vivo. Collectively, these findings revealed that MSC-derived exosomal miR-99b-5p can be transferred into CRC cells and which can suppress tumor progression by targeting FGFR3. This highlights the potential of using exosomal miR-99b-5p as a novel diagnostic marker for CRC, while providing a therapeutic target to combat CRC.

[miR-99b-5p inhibits the activation of NLRP3 inflammasome to alleviate the neurotoxicity induced by paclitaxel chemotherapy]

OBJECTIVE

To study the effects of miR-99b-5p (non-coding RNA) in alleviating pathological neuropathic pain after paclitaxel chemotherapy by inhibiting NLRP3 inflammatory vesicle activation and the effects on neuronal cells pyrosis and apoptosis.

METHODS

SD rats were randomly divided into blank group, model group, agomiR-99b-5P treatment group, and agomiR-NC group, 6 rats in each group. The blank group received saline treatment as a control, the model group established a pain model induced by paclitaxel, and the rats in agomiR-99b-5p treatment group and agomiR-NC group were treated with agomiR-99b-5p and agomiR-NC injections, respectively. The expressions of miR-99b-5p in the blank group, model group, and treatment group were detected by RT-qPCR. The mechanical foot retraction threshold (MWT) of the blank group, model group, and treatment group were detected. TUNEL was used to detect the apoptosis of spinal dorsal horn cells. The levels of ROS, MDA, and SOD were detected by ELISA kits. The protein expressions of NLRP3, caspase-1, and IL-1β were detected by immunofluorescence staining.

RESULTS

Compared with the model group, the expression level of miR-99b-5p and the MWT were increased significantly in agomiR-99b-5p treatment group (P＜0.05), the apoptosis of dorsal horn cells was inhibited (P＜0.05), the level of antioxidant stress was increased in rats, the levels of ROS and MDA were decreased (P＜0.05), while the level of SOD was increased (P＜0.05). Immunofluorescence showed that the expressions of NLRP3, caspase-1, and IL-1β were inhibited by miR-99b-5p.

CONCLUSION

miR-99b-5p can alleviate the apoptosis and pyroptosis of neurons after paclitaxel chemotherapy by inhibiting the activation of NLRP3 and improving oxidative stress in vivo.

Downregulation of miR-99b-5p and Upregulation of Nuclear mTOR Cooperatively Promotes the Tumor Aggressiveness and Drug Resistance in African American Prostate Cancer

Mammalian target of rapamycin (mTOR) regulates various fundamental cellular events including cell proliferation, protein synthesis, metabolism, apoptosis, and autophagy. Tumor suppressive miR-99b-5p has been implicated in regulating PI3K/AKT/mTOR signaling in a variety of types of cancer. Our previous study suggested the reciprocal miR-99b-5p/MTOR (downregulated/upregulated) pairing as a key microRNA-mRNA regulatory component involved in the prostate cancer (PCa) disparities. In this study, we further validated the expression profiles of mTOR and miR-99b-5p in the PCa, colon, breast, and lung cancer specimens and cell lines. The immunohistochemistry (IHC), immunofluorescence, Western blot, and RT-qPCR assays have confirmed that mTOR is upregulated while miR-99b-5p is downregulated in different patient cohorts and a panel of cancer cell lines. Intriguingly, elevated nuclear mTOR expression was observed in African American PCa and other advanced cancers. Transfection of the miR-99b-5p mimic resulted in a significant reduction in nuclear mTOR and androgen receptor (AR), while a slight/moderate to no decrease in cytoplasmic mTOR and AR in PCa and other cancer cells, suggesting that miR-99b-5p inhibits mTOR and AR expression and their nuclear translocation. Moreover, overexpression of miR-99b-5p targets/inhibits AR-mTOR axis, subsequently initiating cell apoptosis and sensitizing docetaxel-induced cytotoxicity in various cancers. In conclusion, our data suggest that reciprocal miR-99b-5p/nuclear mTOR pairing may be a more precise diagnostic/prognostic biomarker for aggressive PCa, than miR-99b-5p/MTOR pairing or mTOR alone. Targeting the AR-mTOR axis using miR-99b-5p has also been suggested as a novel therapeutic strategy to induce apoptosis and overcome chemoresistance in aggressive PCa.

miR-99b-5p, miR-380-3p, and miR-485-3p are novel chemosensitizing miRNAs in high-risk neuroblastoma

Neuroblastoma is a deadly childhood cancer arising in the developing sympathetic nervous system. High-risk patients are currently treated with intensive chemotherapy, which is curative in only 50% of children and leaves some surviving patients with life-long side effects. microRNAs (miRNAs) are critical regulators of neural crest development and are deregulated during neuroblastoma tumorigenesis, making miRNA-based drugs an attractive therapeutic avenue. A functional screen of >1,200 miRNA mimics was conducted in neuroblastoma cell lines to discover miRNAs that sensitized cells to low doses (30% inhibitory concentration [IC₃₀]) of doxorubicin and vincristine chemotherapy used in the treatment of the disease. Three miRNAs, miR-99b-5p, miR-380-3p, and miR-485-3p, had potent chemosensitizing activity with doxorubicin in multiple models of high-risk neuroblastoma. These miRNAs underwent genomic loss in a subset of neuroblastoma patients, and low expression predicted poor survival outcome. In vitro functional assays revealed each of these miRNAs enhanced the anti-proliferative and pro-apoptotic effects of doxorubicin. We used RNA sequencing (RNA-seq) to show that miR-99b-5p represses neuroblastoma dependency genes LIN28B and PHOX2B both in vitro and in patient-derived xenograft (PDX) tumors. Luciferase reporter assays demonstrate that PHOX2B is a direct target of miR-99b-5p. We anticipate that restoring the function of the tumor-suppressive miRNAs discovered here may be a valuable therapeutic strategy for the treatment of neuroblastoma patients.

Human bone marrow mesenchymal stem cells-derived exosomes attenuated prostate cancer progression via the miR-99b-5p/IGF1R axis

MicroRNA-99b-5p (miR-99b-5p) has been shown to be enriched in serum exosomes of prostate cancer (PCa) patients treated with radiotherapy, while its function in PCa progression remains unclear. The expression levels of miR-99b-5p in PCa tissues, cancer cell lines and human bone marrow mesenchymal stem cells (HBMSCs), as well as HBMSCs-derived exosomes were assessed by quantitative real-time PCR (qRT-PCR). MiR-99b-5p mimics or inhibitor was transfected into HBMSCs, and HBMSCs-derived exosomes with abnormal expression of miR-99b-5p were used to stimulate PCa cell-line LNCaP cells. Cell proliferative rate was evaluated using Cell Counting Kit-8 (CCK-8) and 5‐ethynyl‐2′‐deoxyuridine (EdU) staining assays. Cell migration and invasion were analyzed by Transwell assay. The epithelial-mesenchymal transition (EMT) was evaluated by detecting EMT-related markers using Western blot analysis. The animal model was constructed to confirm the function of miR-99b-5p in vivo. The expression levels of MiR-99b-5p were decreased in PCa tissues and cell lines, while elevated in HBMSCs-derived exosomes. HBMSCs-derived exosomes significantly inhibited cell malignant phenotypes of PCa cells, and miR-99b-5p mimics transfected HBMSCs further enhanced the inhibitory effects of HBMSCs on PCa progression. In addition, miR-99b-5p inhibitor transfected HBMSCs-derived exosomes promoted the progression of PCa in vitro. Insulin-like growth factor 1 receptor (IGF1R) was identified as a downstream target of miR-99b-5p. Moreover, miR-99b-5p mimics transfected HBMSCs obviously inhibited tumor progression by downregulating IGF1R in animal model in vivo. Our results demonstrated that HBMSCs could attenuate PCa progression, and exosomal miR-99b-5p and IGF1R participated in the regulatory process, contributing to our understanding of the pathogenic mechanism of PCa.

MiR-99b-5p suppressed proliferation of human osteoblasts by targeting FGFR3 in osteoporosis

Osteoporosis is a common skeletal disease characterized by reduced bone mass partially caused by an imbalance between bone resorption and formation. Considering the potential role of microRNAs (miRNAs) in osteoporosis, we attempted to identify deregulated miRNA that participates in the pathogenesis of osteoporosis. We analyzed online datasets for differentially expressed miRNAs and predicted deregulated miRNA target genes, applied these genes for signaling pathway enrichment annotation, and selected the possible miR-99b-5p/FGFR3 axis. Within osteoporosis bone tissues, miR-99b-5p was upregulated and FGFR3 was downregulated. miR-99b-5p overexpression inhibited osteoblast proliferation and osteogenesis-related genes expression, whereas FGFR3 overexpression exerted opposite effects upon the proliferation of osteoblasts and osteogenesis-related genes expression. By direct targeting, miR-99b-5p inhibited FGFR3 expression. Moreover, FGFR3 silencing significantly reversed the roles of miR-99b-5p inhibition in the proliferation of osteoblasts and osteogenesis-related genes expression. In conclusion, we identify a deregulated miRNA/mRNA axis in osteoporosis and osteogenic differentiation, namely the miR-99b-5p/FGFR3 axis; through targeting FGFR3, miR-99b-5p inhibits osteoblast proliferation and activity, which might subsequently affect the bone formation in osteoporosis progression.

Deep Sequencing Identified Dysregulated Circulating MicroRNAs in Late Onset Preeclampsia

BACKGROUND/AIM

To characterize global microRNA (miRNA) expression profile in the first trimester maternal plasma of women who subsequently develop late-onset preeclampsia (LOPE) compared to uncomplicated pregnancies.

MATERIALS AND METHODS

Five first trimester plasma samples from women who developed LOPE and 5 controls were analyzed using next generation sequencing technology (NGS) followed by target prediction, Gene Ontology analysis and pathway identification. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for confirmation in an independent cohort of 12 LOPE cases and 12 controls.

RESULTS

miR-23b-5p and miR-99b-5p were down-regulated by >1.5 fold in LOPE complicated pregnancies (p value <0.05) compared to controls. Target prediction showed that the major targets of these miRNAs are associated with glycometabolism and immune response.

CONCLUSION

miR-23b-5p and miR-99b-5p are possibly implicated in the pathogenic mechanisms leading to the induction of LOPE and may serve as candidate non-invasive biomarkers for early prediction and prevention.

MiR-99b-5p Attenuates Adipogenesis by Targeting SCD1 and Lpin1 in 3T3-L1 Cells

The number and distribution of adipocytes directly affect the quality of livestock meat products. The analysis of the adipogenesis mechanism is the basis for improving meat quality. The formation of adipocytes is regulated by many factors, including a class of endogenous small RNAs, named microRNA (miRNA). Previous studies have shown that miRNAs could affect adipogenesis by post-transcriptional regulation of target genes. In our study, a decreased miR-99b-5p expression level was found in the adipose tissue of obese mice. Overexpression of miR-99b-5p could increase cell proliferation by promoting the cell cycle while inhibiting cell differentiation. In addition, interference with miR-99b-5p obtained the opposite result. Furthermore, the proteomics sequencing analysis screened 1154 differentially expressed proteins, which are closely related to adipocyte differentiation and fatty acid metabolism. In addition, the results of the dual-luciferase test showed that miR-99b-5p can directly target the proteins SCD1 and Lpin1 with significantly different expression levels in proteomic sequencing. Then, this result was verified at the level of mRNA and protein in a further study. Collectively, these results suggested that miR-99b-5p may be a target for improving meat quality.

miR-10a-5p and miR-29b-3p as Extracellular Vesicle-Associated Prostate Cancer Detection Markers

Extracellular vesicles (EVs) are shed by many different cell types. Their nucleic acids content offers new opportunities for biomarker research in different solid tumors. The role of EV RNA in prostate cancer (PCa) is still largely unknown. EVs were isolated from different benign and malignant prostate cell lines and blood plasma from patients with PCa (n = 18) and controls with benign prostatic hyperplasia (BPH) (n = 7). Nanoparticle tracking analysis (NTA), Western blot, electron microscopy, and flow cytometry analysis were used for the characterization of EVs. Non-coding RNA expression profiling of PC3 metastatic PCa cells and their EVs was performed by next generation sequencing (NGS). miRNAs differentially expressed in PC3 EVs were validated with qRT-PCR in EVs derived from additional cell lines and patient plasma and from matched tissue samples. 92 miRNAs were enriched and 48 miRNAs were depleted in PC3 EVs compared to PC3 cells, which could be confirmed by qRT-PCR. miR-99b-5p was significantly higher expressed in malignant compared to benign EVs. Furthermore, expression profiling showed miR-10a-5p (p = 0.018) and miR-29b-3p (p = 0.002), but not miR-99b-5p, to be overexpressed in plasma-derived EVs from patients with PCa compared with controls. In the corresponding tissue samples, no significant differences in the miRNA expression could be observed. We thus propose that EV-associated miR-10a-5p and miR-29b-3p could serve as potential new PCa detection markers.

Circulating Exosomal miR-150-5p and miR-99b-5p as Diagnostic Biomarkers for Colorectal Cancer

Background: Circulating exosomal miRNAs are potential non-invasive biomarkers for colorectal cancer. The present study aimed to validate the novel sensitive and specific exosomal miRNA biomarkers for diagnosing colorectal cancer (CRC). Patients and Methods: Exosomes isolated from the serum of CRC patients and healthy donors by ultracentrifugation were characterized using TEM, qNano, and immunoblotting. The exosomes from 2 healthy donors and 4 CRC patients were subjected to RNA isolation and miRNA sequencing. The differently expressed miRNAs from 165 primary CRC patients and 153 healthy donors were substantiated by RT-qPCR. Results: The RNA-sequence data analysis revealed that 29 exosomal miRNAs (20 downregulated and 9 upregulated) with >1.5-fold difference between CRC patients and healthy donors were selected. The serum exosomal miR-99b-5p and miR-150-5p levels were significantly downregulated in CRC patients as compared to healthy donors (p < 0.0001 and p < 0.0001, respectively) and benign disease (p = 0.009 and p < 0.0001, respectively). The expression levels of exosomal miR-99b-5p and miR-150-5p were significantly decreased in early CRC patients as compared to healthy donors (p < 0.0001 and p < 0.0001, respectively). The expression levels of exosomal miR-99b-5p and miR-150-5p were significantly increased postoperatively (p = 0.0058 and p < 0.0001, respectively). Conclusions: The present study demonstrated that serum exosomal miRNAs are promising, sensitive, specific, and non-invasive diagnostic biomarkers for CRC. Impact: This is the first study to specifically identify exosomal miR-99b-5p and miR-150-5p associated with CRC. This study, therefore, might deepen the understanding of tumor-derived exosomes for CRC diagnosis.

Identification of PBMC-expressed miRNAs for rheumatoid arthritis

Post-transcriptional regulation by miRNAs plays an important role in the pathogenesis of rheumatoid arthritis (RA), however, the roles of specific miRNAs in RA pathogenesis remain largely unclear. This study performed dual-omics (miRNA and mRNA) integration analysis and in-depth cellular and molecular functional exploration to identify novel RA-associated miRNAs and to understand their underlying pathogenic mechanism. Based on the miRNA and mRNA expression profiles in peripheral blood mononuclear cells (PBMCs) from a discovery sample set (25 RA cases and 18 healthy controls), 18 differentially expressed miRNAs (DEMIRs) (|Fold-change|>2 and P < 0.05) were identified and corresponding interaction networks of DEMIRs and mRNA were constructed. After the expression validation of the DEMIRs in a validation sample set (35 RA cases and 35 healthy controls), miR-99b-5p was highlighted. The over-expression of newly discovered miR-99b-5p is able to suppress T cell apoptosis, promote cell proliferation and activation, increase expression of proinflammatory cytokines (IL-2, IL-6, TNF-α, and IFN-γ), and inhibit expression of its target genes mTOR and RASSF4. This study comprehensively identified PBMC-expressed miRNAs along with corresponding regulatory networks significant for RA and discovered miR-99b-5p as a novel post-transcriptional mediator involved in RA pathogenesis. The findings improved our understanding of RA pathogenesis and provided novel insights into the molecular mechanisms underlying RA pathogenesis.

miRNA-99b-5p targets FZD8 to inhibit non-small cell lung cancer proliferation, migration and invasion

Background

miRNAs were found to play crucial roles in regulating cellular behaviors. The aim of this study was to investigate the biological function of miRNA-99b-5p (miR-99b-5p) in non-small cell lung cancer (NSCLC).

Materials and methods

miR-99b-5p expression level in NSCLC cell lines was detected by quantitative real-time PCR (qRT-PCR). Cell proliferation, migration and invasion were examined by cell counting kit-8 (CCK-8) assay, wound-healing assay and Transwell invasion assay, respectively. Dual-luciferase activity reporter assay and Western blot assay were conducted to validate the target of miR-99b-5p.

Results

The expression of miR-99b-5p was decreased in NSCLC cell lines compared with normal cell line. Overexpression of miR-99b-5p inhibits cell proliferation, migration and invasion in vitro. FZD8 was validated as a direct target of miR-99b-5p. Overexpression of FZD8 partially abolished the effects of miR-99b-5p mimic on NSCLC cell behaviors.

Conclusion

Collectively, our results demonstrated that miR-99b-5p inhibits NSCLC cell proliferation, migration and invasion through targeting FZD8. This newly identified miR-99b-5p/FZD8 axis provided novel insights into the mechanisms underlying NSCLC progression.

miRNA-99b-5p suppresses liver metastasis of colorectal cancer by down-regulating mTOR

Liver metastasis is common in patients diagnosed with colorectal cancer (CRC), and is also correlated with poor outcome. In this study we screened the different expression profiles of microRNAs (miRNAs) on the development of liver metastasis in CRC patients. miR-99b-5p was found to be more than 6-fold higher in primary tumors than in matched liver metastases (P = 0.007). Expression of miR-99b-5p in primary tumors of patients with stage III CRC without liver metastases was higher than in CRC patients with liver metastases (P = 0.028). Up-regulated miR-99b-5p was associated with longer overall survival (P = 0.01). Besides, miR-99b-5p silencing in miR-99b-5p-positive CRC cell lines promoted cell migration and up-regulated mTOR, and vice versa. In addition, luciferase assays demonstrated that miR-99b-5p functioned as a tumor suppressor by targeting mTOR. Taken together, our results demonstrate thatmiR-99b-5p is differently expressed in primary CRC and liver metastasis and functions as a tumor-suppressive microRNA in metastatic CRC. The miR-99b-5p–mTOR axis may serve as a prognostic factor and therapeutic target for anti-metastatic therapy in CRC patients.