Research progress in effects of microRNA-15a and microRNA-16 on fibrotic diseases. / å¾®RNA-15a和微RNA-16åœ¨çº¤ç»´åŒ–ç–¾ç— ä¸­ä½œç”¨çš„ç ”ç©¶è¿›å±•.

MicroRNA (miR) is a class of highly conserved non-coding single-stranded RNA widely existing in mammals, which can negatively regulate the expression of targeting genes after transcription. As a key regulator, miR negatively regulates the expression of the targeting genes and disrupts important molecular signaling pathways, leading to the imbalance of multiple pathways such as tissue repair and inflammation involved in the fibrotic process. Among them, miR-15a/16 can participate in regulating and controlling the fibrotic process of various organs, including liver, lung, heart, kidney and other fibrotic diseases by acting on cell proliferation and transformation, extracellular matrix proteins production and degradation, inflammation and other important cell functions. It has potential diagnostic and therapeutic value. Clarifying the biological function of miR-15a/16 and its mechanism for action and therapeutic application prospects in various fibrotic lesions are of great significance for the molecular targeted treatment of fibrotic diseases.

Exosomal AFAP1-AS1 binds to microRNA-15a-5p to promote the proliferation, migration, and invasion of ectopic endometrial stromal cells in endometriosis.

BACKGROUND: Endometriosis (EMS) remains a major challenge to reproductive health due to multifactorial etiology, disease heterogeneity, and the lack of appropriate diagnostic markers and treatment. Eexosome (Exo) has become a major factor in progression of a variety of diseases. However, the mechanisms directing their role in the pathophysiology of EMS are ill-defined. Here, we aimed to investigate the clinical implications of actin filament associated protein 1-Antisense RNA 1 (AFAP1-AS1) in EMS. METHODS: Bioinformatics analysis was used to predict the expression and interaction of AFAP1-AS1, miR-15a-5p and BCL9 in EMS, and dual luciferase reporter assay was used to verify the targeted relationship of AFAP1-AS1, miR-15a-5p, and BCL9. The Exo from endometrial stromal cells (ESCs) was isolated and characterized by transmission electron microscopy (TEM) and Nanoparticle tracking analysis (NTA). Exosome uptake studies were performed. For in vitro assay, ectopic ESCs (EcESCs) proliferation, migration, and invasion were assessed by CCK-8 and Transwell assays. In vivo assay was performed by establishment of EMS mice to validate the result derived from in vitro assay. RESULTS: The Exo was successfully isolated from ESCs and we observed high expression of AFAP1-AS1 and BCL9 but low expression of miR-15a-5p in EMS. Moreover, Exo derived from EcESCs could deliver AFAP1-AS1 to EcESCs and thus promoting proliferation, migration, and invasion of ESCs. AFAP1-AS1 bound to BCL9, which was targeted by miR-15a-5p in EMS. In vivo experiments in nude mice revealed that inhibition of Exosomal AFAP1-AS1 suppressed migration and invasion of EcESCs through miR-15a-5p/BCL9. CONCLUSIONS: Collectively, these findings suggested that ESCs-derived Exo carrying AFAP1-AS1 contributed to EMS pathogenesis. This study might help us realize the etiology of EMS and improve the treatment of the related complications.

Bone marrow mesenchymal stem cell-derived exosomes carrying long noncoding RNA ZFAS1 alleviate oxidative stress and inflammation in ischemic stroke by inhibiting microRNA-15a-5p.

BACKGROUND/AIM: Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can prevent oxidative stress and inflammation in cerebral ischemia-reperfusion injury. This study intended to assess influences of BMSC-released exosomes on oxidative stress and inflammation following ischemic stroke. METHODS: In vitro and in vivo models were developed using oxygen-glucose deprivation/reperfusion (OGD/R) and middle cerebral artery occlusion (MCAO), respectively. After exosome isolation, co-culture experiments of BMSCs or BMSC-derived exosomes and OGD/R-treated BV-2 cells were implemented to evaluate the impacts of BMSCs or BMSC-secreted exosomes on proliferation, inflammation, oxidative stress, and apoptosis. The gain-of-function experiments of ZFAS1 or microRNA (miR)-15a-5p were conducted to investigate the associated mechanisms. Besides, MCAO mice were injected with exosomes from BMSCs overexpressing ZFAS1 for in vivo verification. The binding of ZFAS1 to miR-15a-5p was assessed through dual-luciferase reporter gene assay. RESULTS: Co-culture with BMSCs accelerated proliferation and downregulated IL-1ß, IL-6, and TNF-α in OGD/R-exposed BV-2 cells, accompanied by increased SOD level and decreased MDA level and apoptosis, all of which were nullified by inhibiting exosome secretion. Mechanistically, ZFAS1 bound to miR-15a-5p to negatively orchestrate its expression. In addition, BMSC-released exosomes or BMSC-secreted exosomal ZFAS1 augmented proliferation but reduced oxidative stress, apoptosis, and inflammation in OGD/R-exposed BV-2 cells, whereas these impacts of BMSC-released exosomal ZFAS1 were nullified by overexpressing miR-15a-5p. Moreover, BMSC-derived exosomal ZFAS1 diminished MCAO-induced oxidative stress, cerebral infarction, and inflammation in mice. CONCLUSIONS: Conclusively, BMSC-released exosomes might carry long noncoding RNA ZFAS1 to curb oxidative stress and inflammation related to ischemic stroke, which was possibly realized through miR-15a-5p inhibition.

STAT3/miR-15a-5p/CX3CL1 Loop Regulates Proliferation and Migration of Vascular Endothelial Cells in Atherosclerosis.

Endothelial cell proliferation disorder caused by vascular injury seems to be one of the causes of atherosclerosis, which is the pathological basis of coronary heart disease. The role of STAT3 in the regulation of microRNAs and endothelial dysfunction in atherosclerosis is unclear. STAT3 can be activated by cytokine IL-6 and up regulate the expression of CX3CL1. In addition, microRNA-15a-5p (miR-15a-5p) inhibited the transcription of CX3CL1, the proliferation of vascular endothelial cells and the proliferation of STAT3 regulated vascular endothelial cells. STAT3 positively regulates the expression of CX3CL1, and then down-regulates the inhibition of CX3CL1 by over-expression of miR-15a-5p, thus forming an elimination feedback loop to control the proliferation of HUVECs and affect the progression of atherosclerosis. In conclusion, miR-15a-5p may be the therapeutic target of the pathological basis of coronary atherosclerosis.

Knockdown of long non-coding RNA TUG1 depresses apoptosis of hippocampal neurons in Alzheimer's disease by elevating microRNA-15a and repressing ROCK1 expression.

OBJECTIVE: Many studies have already suggested the role of long non-coding RNAs (lncRNAs) in Alzheimer's disease (AD), but the functions of lncRNA Taurine Upregulated Gene 1 (TUG1) in AD have been scarcely discussed. This study aims to verify how TUG1 affects hippocampal neurons in AD through modulation of microRNA-15a (miR-15a)/Rho-associated protein kinase 1 (ROCK1). METHOD: AD mice was modeled through injection of ß-amyloid 25-35 (Aß25-35) into the lateral ventricle. After modeling, the mice were injected with altered TUG1 and/or miR-15a agomir lentiviruses. The spatial learning ability and memory ability of mice were detected through Morris water maze test. Hippocampal neuronal apoptosis and oxidative stress indicators in AD mice were then detected. The hippocampal neuron AD model was induced by Aß25-35. Next, the neurons were, respectively, transfected with altered TUG1 vector and/or miR-15a mimics to determine the proliferation inhibition and apoptosis of hippocampal neurons. The interactions between TUG1 and miR-15a, and between miR-15a and ROCK1 were assessed using bioinformatic prediction, dual luciferase reporter gene assay and RNA-pull-down assay. RESULTS: In the animal models, Aß25-35-induced mice exhibited decreased spatial learning and memory ability, obvious pathological injury, promoted hippocampal neuronal apoptosis and decreased antioxidant ability. TUG1 silencing and miR-15a elevation improved spatial learning ability and memory ability, ameliorated pathological injury, depressed neuronal apoptosis, and strengthened antioxidant ability of hippocampal neurons in AD mice. In cellular models, Aß25-35-treated hippocampal neurons presented inhibited neuronal viability and promoted neuronal apoptosis. TUG1 silencing and miR-15a elevation increased viability and limited apoptosis of Aß25-35-treated hippocampal neurons. TUG1 specifically bound to miR-15a, and miR-15a targeted ROCK1. CONCLUSION: Collectively, this study reveals that TUG1 knockdown restricts apoptosis of hippocampal neurons in AD by elevating miR-15a and suppressing ROCK1 expression, and provides a new therapeutic target for AD treatment.

MicroRNAs 15A and 16-1 Activate Signaling Pathways That Mediate Chemotaxis of Immune Regulatory B cells to Colorectal Tumors.

BACKGROUND & AIMS: B cells infiltrate tumors, but little is known about how they affect tumor growth and progression. microRNA15A (MIR15A or miRNA15A) and microRNA16-1 (MIR16-1 or miRNA16-1) regulate cell proliferation, apoptosis, and drug resistance. We investigated their involvement in B-cell-mediated immune suppression by colorectal tumors. METHODS: Mice with disruptions of the gene cluster that encodes MIR15A and MIR16-1 (knockout mice), and control (C57BL/B6) mice were given azoxymethane with dextran sodium sulfate (AD) to induce formation of colorectal tumors. Mice were given anti-CD20 to delete B cells, or injections of agomir to increase MIR15A and MIR16-1. Proliferation of CD8+T cells was measured by carboxyfluorescein-succinimidyl-ester analysis. Colon tissues were collected from mice and analyzed by flow cytometry, microRNA (miRNA) sequencing, and for cytokine production. Intestinal epithelial cells (IECs) were isolated and transfected with miRNA mimics, to identify their targets. We analyzed miRNA expression patterns and quantified B cells in colorectal cancer tissue microarrays derived from 90 patients who underwent surgical resection, from July 2006 through April 2008, in Shanghai, China; expression data were compared with clinical outcomes. RESULTS: Tumors that developed in knockout mice following administration of AD were larger and contained greater numbers of B cells than tumors that grew in control mice. Most of the B cells in the tumors were positive for immunoglobulin A (IgA+). IgA+ B cells expressed high levels of immune regulatory molecules (programmed death ligand 1, interleukin 10, and transforming growth factor beta), and repressed the proliferation and activation of CD8+ T cells. Levels of MIR15A and MIR16-1 were reduced in colon tumors from mice, compared with nontumor colon tissue. Incubation of IECs with IL17A reduced expression of MIR15A and MIR16-1. Transgenic expression of MIR15A and MIR16-1 in IECs decreased activation of NF-κB and STAT1 by reducing expression of I-kappaB kinases; this resulted in reduced production of chemokine (C-X-C motif) ligands 9 and 10 and decreased chemotaxis of IgA+ B cells. Tumors in mice injected with AD and agomir grew more slowly than tumors in mice not given in agomir and contained fewer IgA+ B cells. We found a negative correlation between levels of MIR15A and MIR16-1 and numbers of IgA+B cells in human colorectal tumor tissues; high levels of MIR15A and MIR16-1 and low numbers of IgA+B cells were associated with longer survival times of patients. CONCLUSIONS: We found increased levels of MIR15A and MIR16-1 to reduce numbers of IgA+ B cells in colorectal tumor tissues and correlate with increased survival time of patients. In mice that lack MIR15A and MIR16-1, colon tumors grow more rapidly and contain increased numbers of IgA+ B cells. MIR15A and MIR16-1 appear to activate signaling pathways required for B-cell-mediated immune suppression.

Tripterine inhibits proliferation, migration and invasion of breast cancer MDA-MB-231 cells by up-regulating microRNA-15a.

Breast cancer is the most commonly diagnosed cancer in women worldwide. Tripterine is an important active component isolated from Triperygium wilfordii Hook F. This study investigated the effects of tripterine on breast cancer cell proliferation, migration, invasion and apoptosis, as well as microRNA-15a (miR-15a) expression. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to measure the expression of miR-15a. Cell transfection was conducted to change the expression of miR-15a. Viability, proliferation, migration, invasion and apoptosis of MDA-MB-231 cells were assessed using the cell counting kit-8 (CCK-8) assay, BrdU incorporation assay, Annexin V-FITC/PI apoptosis detection kit and two-chamber Transwell assay, respectively. Expression of key factors involving in cell proliferation, migration, invasion and apoptosis, as well as the PI3K/AKT and JNK pathways, were evaluated using Western blotting. We found that tripterine inhibited MDA-MB-231 cell viability, proliferation, migration and invasion, but induced cell apoptosis. Moreover, tripterine up-regulated the expression of miR-15a in a concentration-dependent manner and miR-15a participated in the effects of tripterine on MDA-MB-231 cell proliferation, migration, invasion and apoptosis. In addition, tripterine inactivated PI3K/AKT and JNK pathways in MDA-MB-231 cells by up-regulating miR-15a. In conclusion, tripterine inhibited proliferation, migration and invasion of breast cancer MDA-MB-231 cells by up-regulating miR-15a and inactivating PI3K/AKT and JNK pathways.

Exosome-transmitted LINC00461 promotes multiple myeloma cell proliferation and suppresses apoptosis by modulating microRNA/BCL-2 expression.

BACKGROUND: Multiple myeloma (MM) is a hematologic cancer caused by the abnormal expansion of plasma cells, but the exact mechanism underlying MM development is not completely known. Recently, multiple long noncoding RNAs (lncRNAs) were implicated in the regulation of MM development. METHODS: Samples from patients with MM were collected and detected for LINC00461 expression using real-time polymerase chain reaction (PCR). LINC00461 was knocked down in MM cell lines by short hairpin RNAs (shRNAs) to measure its effect on MM cell proliferation and apoptosis. The function of mesenchymal stromal cell (MSC)-derived exosomes was analyzed using chamber assays. RESULTS: LINC00461 was highly expressed in MM. Knockdown of LINC00461 dramatically reduced MM cell proliferation and induced cell apoptosis. Further study showed that LINC00461 relieved the inhibitory effect of microRNA (miR)-15a/miR-16 on BCL-2. In addition, we observed that MSC-derived exosomes promoted MM cell proliferation through LINC00461. CONCLUSION: Our findings demonstrate that LINC00461, a sponge for miR-15a/16, is highly expressed in MSC-derived exosomes, and enhances MM cell proliferation, which may become an excellent candidate for therapeutic applications.

Evaluation of the expression level of microRNA-21, microRNA-15a, microRNA-372 in human follicular fluid stem cells-derived oocyte-like cells (OLCs).

OBJECTIVE: Today, researchers have succeeded in achieving oocyte-like cells through the in vitro differentiation of stem cells. MicroRNAs are key regulators of oocyte development. In this study we decided to evaluate the expression pattern of microRNA-21, microRNA-15a, and microRNA-372 in oocyte-like cells, to determine the maturation stage of oocyte-like cells. METHODS: Human follicular fluid samples were collected and centrifuged, and their cells were divided into 3 groups; day 7 as control group, days 14 and 21. During this period, the cells were evaluated for their morphological appearance and viability by inverted microscopy. RNA isolation was performed and cDNA was reversely transcribed by specific stem-loop RT primers. Real-time RT-PCR was used to detect microRNA expression. RESULTS: The relative expression of microRNA-21 and microRNA-15a on day 21 was significantly down-regulated compared to the control group (day 7), but microRNA-372 did not show a significant difference. Also, on day 14 compared to the control group (day 7), microRNA-21 did not show a significant difference; but microRNA-15a and microRNA-372 were significantly down-regulated. MicroRNA-21 and microRNA-15a on day 21 compared to day 14 revealed down-regulated levels, but microRNA-372 revealed up-regulated levels. CONCLUSIONS: Our results showed significant decreases in the expression of microRNA-21 and microRNA-15a in oocyte-like cells, as well as in oocytes, which may lead to cytoplasmic maturation, germinal vesicle break down and the completion of meiosis І. In addition, down-regulation expression of microRNA-372 maybe a confirmation that mesenchymal stem cells have differentiated into germ cells, and these cells were differentiated into oocyte-like cells.

[Retracted] MicroRNA­15a­5p­targeting oncogene YAP1 inhibits cell viability and induces cell apoptosis in cervical cancer cells.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that certain of the Transwell invasion assay data shown in Fig. 3A and B on p. 1306 were strikingly similar to data appearing in different form in a paper by different authors at a different research institute that had already been submitted for publication. Owing to the fact that the contentious data in the above article had already been submitted for publication prior to its submission to International Journal of Molecular Medicine, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they accepted the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Molecular Medicine 46: 1301­1310, 2020; DOI: 10.3892/ijmm.2020.4704].

Scutellarin inhibits glioma cell proliferation by up-regulating miR-15a expression.

OBJECTIVE: To investigate the effect of scutellarin on the proliferation of glioma cells through microRNA (miR)-15a. METHODS: Human glioma cell line T98G was cultured in vitro and divided into control group (without treatment), scutellarin group (with 10, 20, 40, 80, 160 µg/mL scutellarin, respectively), miR-15a negative control group (transfected with negative control-miR-15a + 80 µg/mL scutellarin) and miR-15a inhibitor group (transfected with miR-15a siRNA + 80 µg/mL scutellarin). The proliferation of T98G cells was detected by cell counting kit-8 (CCK-8), and the expression of miR-15a in T98G cells was detected by real-time fluorescence quantitative PCR (qRT-PCR). The apoptosis of T98G cells was assessed by flow cytometry, and the invasion of T98G cells was compared by Transwell method. The levels of proliferating cell nuclear antigen (PCNA), Bcl-2 related X protein (Bax) and matrix metalloproteinase 9 (MMP-9) in T98G cells were detected by Western blot (WB). RESULTS: Compared with that in the control group, the OD value of T98G cells in scutellarin group was significantly lower (P<0.05), with the increase of scutellarin concentration, the OD value of T98G cells decreased in turn, and 80 µg/mL was used as the optimal concentration of scutellarin to treat T98G cells for subsequent experiments. Compared with those in the control group, the miR-15a expression, apoptosis rate and Bax protein expression in T98G cells of scutellarin group were higher (P<0.05), and the OD value, number of invasive cells, PCNA and MMP-9 protein levels were lower (P<0.05). Compared with scutellarin group and miR-15a negative control group, the miR-15a expression, apoptosis rate and Bax protein expression in T98G cells of miR-15a inhibitor group were lower (P<0.05), and the OD value, number of invasive cells, PCNA and MMP-9 protein levels were higher (P<0.05). CONCLUSIONS: Scutellarin can inhibit the proliferation, invasion and induce the apoptosis of glioma cells, which may be mediated by up-regulating the expression of miR-15a.

Generation of miR-15a/16-1 cluster-deficient human induced pluripotent stem cell line (DMBi001-A-2) using CRISPR/Cas9 gene editing.

miR-15a/16-1 cluster, composed of MIR15A and MIR16-1 genes located in close proximity on chromosome 13 was described to regulate post-natal cell cycle withdrawal of cardiomyocytes in mice. In humans, on the other hand, the level of miR-15a-5p and miR-16-p was negatively associated with the severity of cardiac hypertrophy. Therefore, to better understand the role of these microRNAs in human cardiomyocytes in regard to their proliferative potential and hypertrophic growth, we generated hiPSC line with complete deletion of miR-15a/16-1 cluster using CRISPR/Cas9 gene editing. Obtained cells demonstrate expression of pluripotency markers, differentiation capacity into all three germ layers and normal karyotype.

MicroRNA-15a/ß1,4-GalT-I axis contributes to cartilage degeneration via NF-κB signaling in osteoarthritis.

OBJECTIVE: Osteoarthritis is a condition characterized by articular cartilage degradation. The increased expression of ß1,4-Galactosyltransferase-I (ß1,4-GalT-I) in the articular cartilage of osteoarthritis patients was related to an inflammatory response. The aim of this study was to elucidate the role of ß1,4-GalT-I in osteoarthritis. This study aimed to determine the function of 1,4-GalT-I in osteoarthritis. METHODS: The osteoarthritis mouse model with the destabilization of the medial meniscus was established by microsurgical technique. Pathological changes in articular cartilage were observed by hematoxylin and eosin staining and safranin O-fast green staining. Quantitative real-time polymerase chain reaction, western blot, and enzyme-linked immunosorbent assays were used to observe mRNA and protein expression, respectively. RNA interactions were verified by a luciferase reporter assay. SA-ß-Gal staining was used to assess chondrocyte senescence. Immunofluorescence staining was conducted to observe the localization of Nuclear Factor-kappaB (NF-κB). RESULTS: ß1,4-GalT-I and microRNA-15a (miR-15a) show high and low expression in the articular cartilage of osteoarthritis, respectively. MiR-15a inhibits the mRNA translation of ß1,4-GalT-I. ß1,4-GalT-I promotes extracellular matrix degradation, senescence, and NF-κB activation in IL-1ß-stimulated chondrocytes, which can be reversed by overexpression of miR-15a. Intra-articular injection of microRNA-15a ameliorates cartilage degeneration by inhibiting ß1,4-GalT-I and phosphorylation of NF-κB in vivo. CONCLUSION: The authors clarified that the miR-15a/ß1,4-GalT-I axis inhibits the phosphorylation of NF-κB thereby inhibiting extracellular matrix degradation and senescence in chondrocytes to alleviate cartilage degeneration in osteoarthritis. MiR-15a and ß1,4-GalT-I may serve as potentially effective targets for the future treatment of osteoarthritis.

Human umbilical cord-mesenchymal stem cells-derived exosomes carrying microRNA-15a-5p possess therapeutic effects on Wilms tumor via regulating septin 2.

The exact mechanism of miR-15a-5p shuttled by human umbilical cord-mesenchymal stem cell-derived exosomes (hUC-MSCs-Exo) in Wilms tumor (WT) was estimated. WT tissues were collected clinically. miR-15a-5p and septin 2 (SEPT2) expression levels were examined in tissues . hUC-MSCs-Exo were transfected with miR-15a-5p-related oligonucleotides and co-cultured with WT cells (G-401). In addition, SEPT2 loss-of-function was performed in G-401 cells. The biological functions of G-401 cells after treatments were evaluated. Moreover, tumor formation tests further assessed the role of exosomal miR-15a-5p in WT. The miR-15a-5p level was lower and the SEPT2 level was higher in WT. hUC-MSCs-Exo impaired the biological functions of G-401 cells. hUC-MSCs-Exo carried upregulated miR-15a-5p into G-401 cells, thereby lessening the tumorigenic properties of G-401 cells. Inhibition of SEPT2 suppressed the biological function of WT cells and upregulated SEPT2 reversed hUC-MSCs-Exo-mediated inhibition of G-401 cell growth. The tumorigenicity of G-401 cells in mice was impaired by hUC-MSCs-Exo overexpressing miR-15a-5p. The data prove that miR-15a-5p shuttled by hUC-MSCs-Exo negatively regulates SEPT2 expression, and disrupts WT cell growth in vivo and in vitro.

Assessment of MicroRNA-15a and MicroRNA-16-1 Salivary Level in Oral Squamous Cell Carcinoma Patients.

BACKGROUND: Squamous Cell Carcinoma (SCC) includes more than 90% of malignancies of the oral cavity. Early diagnosis could effectively improve patients' quality of life and treatment outcomes of oral cancers. MicroRNAs as non-encoding genes have great potential to initiate or suppress cancer progression. Recent studies have shown that disruption of micro-RNA regulation is a common occurrence in cancers. OBJECTIVE: This study set out to evaluate the expression of microRNA-15a (miR-15a) and microRNA- 16-1 (miR-16-1) in the saliva of Oral Squamous Cell Carcinoma (OSCC) patients in comparison with a healthy control group. METHODS: This case-control study was performed on fifteen patients with OSCC and fifteen healthy volunteers as the control group. A 5 ml of non-stimulating whole saliva was collected by spitting method from patients and controls and stored at -70°C. The expression of miR-15a and miR-16-1 was investigated using quantitative Reverse-Transcription Polymerase Chain Reaction (RT-qPCR). RESULTS: MiR-15a and miR-16-1 were downregulated in OSCC patients compared with the control group (p<0.001). The sensitivity of miR-15a and miR-16-1 in differentiating OSCC patients from healthy individuals was 93.3% and 86.67%, respectively, and their specificity was 86.67% and 92.33%, respectively. The diagnostic accuracy of miR-15a was 90%, and miR-16-1 was 93.3%. CONCLUSION: The present study showed a decrease in the relative expression of miR-15a and miR-16-1 in OSCC patients compared with healthy individuals. It is probable to introduce salivary values of miR-15a and miR-16-1 as a non-invasive tool for early detection of OSCC. Decreased expression of miR-15a and miR-16-1 in OSCC indicates the possible effective role of these genes in OSCC etiopathogenesis.

Circular RNA SLC26A4 regulates the maturation of microRNA-15a in non-small cell lung cancer cells.

To the best of our knowledge, the oncogenic role of circular RNA solute carrier family 26 member 4 (circSLC26A4) has only been reported in cervical cancer, while its role in non-small cell lung cancer (NSCLC) is unknown. The present study explored the involvement of circSLC26A4 in NSCLC. NSCLC tissues and paired adjacent non-tumor tissues were collected from 64 patients with NSCLC. The expression levels of circSLC26A4, mature microRNA-15a (miR-15a) and miR-15a precursor in these tissues were determined by reverse transcription-quantitative PCR (RT-qPCR). NSCLC cells were transfected with pcDNA3.1-circSLC26A4 vector to overexpress circSLC26A4, followed by the measurement of the expression levels of mature miR-15a and miR-15a precursor using RT-qPCR. Cell proliferation was analyzed using a Cell Counting Kit-8 assay. circSLC26A4 expression was upregulated in NSCLC tissues, and its high expression was significantly associated with poor survival of patients with NSCLC. The expression levels of circSLC26A4 were correlated with the expression levels of mature miR-15a, but not the expression levels of miR-15a precursor in NSCLC tissues. In NSCLC cells, overexpression of circSLC26A4 was associated with downregulation of mature miR-15a expression, but not miR-15a precursor expression. A cell proliferation assay revealed that overexpression of circSLC26A4 reduced the inhibitory effects of overexpression of miR-15a on cell proliferation. Therefore, circSLC26A4 may suppress the maturation of miR-15a in NSCLC to inhibit cancer cell proliferation.

Exosomal microRNA-15a from ACHN cells aggravates clear cell renal cell carcinoma via the BTG2/PI3K/AKT axis.

Accumulating studies have indicated that exosomal microRNAs (miRNAs/miRs) can mediate clear cell renal cell carcinoma (ccRCC) at the early stage, but the mechanisms remain to be specified. Here, we investigated the mechanism of exosomal miR-15a in ccRCC. After successful isolation of exosomes from RCC cells, we found that miR-15a was upregulated in ccRCC cells. Moreover, upregulation of miR-15a by pre-miR-15a promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition of ccRCC cells. A luciferase assay revealed that B-cell translocation gene 2 (BTG2) was a target gene of miR-15a and negatively correlated with miR-15a expression. BTG2 was poorly expressed in ccRCC, which reduced the proliferation of ccRCC cells. In addition, overexpression of BTG2 could reverse the promotive effects of miR-15a on ccRCC. Furthermore, BTG2 reduced PI3K/AKT pathway activity. Our results collectively indicated that exosomal miR-15a from RCC cells accelerated cell viability by downregulating BTG2 and promoting the activity of the PI3K/AKT signaling pathway. We demonstrated a novel mechanism by which exosomal miR-15a exerted pro-proliferatory effects on ccRCC, highlighting the potential of exosomal miR-15a as a target for ccRCC prognosis.

MicroRNA-15a Carried by Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibits the Immune Evasion of Colorectal Cancer Cells by Regulating the KDM4B/HOXC4/PD-L1 Axis.

The relevance of microRNA-15a (miR-15a) to autoimmunity has been reported. Herein, we intended to probe the potential roles of miR-15a shuttled by adipose-derived mesenchymal stem cells (adMSCs)-derived extracellular vesicles (Evs) in colorectal cancer (CRC). Initially, CRC cells were treated with interferon gamma (IFN-γ) to screen out differentially expressed genes by transcriptome sequencing. Following a 24-h co-culture with 20 µM adMSCs-derived Evs, CRC cell viability, migration, invasion, and apoptosis were assessed. After the determination of histone lysine demethylase 4B (KDM4B) as our target, its regulatory miRNA was predicted by the bioinformatics websites and verified by dual-luciferase and RNA pull-down assays. Intriguingly, KDM4B downregulated homeobox C4 (HOXC4) expression, while HOXC4 bound to the promoter sequence of programmed death-ligand 1 (PD-L1). Thus, we conducted rescue experiments to study the role of KDM4B and HOXC4. Finally, we evaluated the effects of adMSCs on CRC cell growth and immune evasion through in vivo tumorigenesis experiments. AdMSCs-derived Evs overexpressing miR-15a repressed proliferation, migration, and invasion, while it promoted the apoptosis of CRC cells via downregulation of KDM4B. These in vivo findings were reproduced in vitro on CRC immune evasion. Collectively, adMSCs-derived Evs overexpressing miR-15a restricted the immune evasion of CRC via the KDM4B/HOXC4/PD-L1 axis.

The expression level and prognostic value of microRNA-15a-5p in endometrial carcinoma.

BACKGROUND: Recent studies have shown that the microRNA-15a-5p (miR-15a-5p) plays varying roles in different malignancies. However, to date, the role and prognostic value of miR-15a-5p in patients with endometrial cancer has not been explored. This study investigated the expression level of miR-15a-5p in endometrial carcinoma and its prognostic value. METHODS: A total of 108 patients with endometrial cancer treated in our hospital from January 2015 to January 2016 were enrolled in this study. The patients were followed up for 5 years. Patients who experienced recurrence or metastasis after surgery were assigned into the recurrence and metastasis group (n=45) and the remaining patients were assigned into the control group (n=63). The expression level of microRNA-15a-5p in endometrial cancer was analyzed. Furthermore, the correlation between the expression of miR-15a-5p and the pathological features and prognosis was examined. RESULTS: The expression of miR-15a-5p in endometrial carcinoma was significantly lower than that in adjacent healthy tissues (2.22±0.75 vs. 2.59±0.91, P=0.000). Furthermore, the expression of miR-15a-5p in the endometrial cancer tissues of patients in the recurrence and metastasis group was significantly lower than that observed in patients in the control group (1.91±0.62 vs. 2.45±0.75, P=0.000). The receiver operating characteristic curve was used to analyze the predictive value of miR-15a-5p in endometrial cancer tissue for postoperative recurrence or metastasis in endometrial cancer patients. The area under the curve was 0.690 [95% confidence interval (CI): 0.601 to 0.798, P=0.000], the best cut-off value of diagnosis was 2.325, the sensitivity was 0.619, and the specificity was 0.733. Multivariate logistic regression analysis showed that miR-15a-5p expression <2.325 was a risk factor for postoperative recurrence or metastasis of endometrial cancer [odds ratio (OR) =3.544 (95% CI: 1.489 to 8.436), P=0.004]. Furthermore, the expression of miR-15a-5p in endometrial carcinoma was correlated with lymph node metastasis, TNM stage, and patient mortality. CONCLUSIONS: The expression of miR-15a-5p in endometrial carcinoma is related to lymph node metastasis, TNM stage, and mortality. Furthermore, the expression of miR-15a-5p was significantly decreased in endometrial cancer patients with recurrence or metastasis and thus, miR-15a-5p may have certain value in predicting postoperative recurrence or metastasis in such patients.

hsa­miR­15a­5p inhibits colon cell carcinoma via targeting CCND1.

Colon carcinoma is one of the most common cancers worldwide. Epidemiological studies have revealed that colon cancer is the third leading cause of cancer­related deaths, which is due to the increased incidence and mortality rates. However, the treatment strategies for colon cancer remain unsatisfactory for patients, especially for those with advanced or recurrent colon cancer. Dysregulated microRNAs (miRNAs) are considered to influence tumor development and metastasis. However, the molecular mechanism through which miRNAs affect cancer progression is not yet completely understood. The aim of the present study was to investigate the expression levels of has­miR­15a­5p and its molecular mechanism in colon cell carcinoma. In the present study, the expression levels of hsa­miR­15a­5p were found to be decreased in colon tumor tissues and cancer cell lines. Hsa­miR­15a­5p overexpression inhibited colon cell proliferation and migration. Mechanistically, the G1/S­specific cyclin­D1 (CCND1) gene was predicted as a target of hsa­miR­15a­5p, as evidenced by bioinformatics and dual­luciferase reporter assay analyses. CCND1 overexpression significantly increased the progression of colon cancer. Furthermore, CCND1 was demonstrated to mediate the effects of hsa­miR­15a­5p on colon cancer cells. The present study demonstrated that hsa­miR­15a­5p alleviated the proliferation, migration and invasion of colon cancer by targeting the CCND1 gene, which represents a potential molecular target for the diagnosis and treatment of colon cancer.