Cancer-associated fibroblasts-derived exosomes upregulate microRNA-135b-5p to promote colorectal cancer cell growth and angiogenesis by inhibiting thioredoxin-interacting protein

ObjectiveThe role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP).MethodsCRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed.ResultsMiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p,ConclusionCAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.     

Circ_0005615 promotes cervical cancer cell growth and metastasis by modulating the miR-138-5p/KDM2A axis

Cervical cancer (CC) is a highly fatal gynecological malignancy due to its high metastasis and recurrence rate. Circular RNA (circRNA) has been regarded as a regulator of CC. However, the underlying molecular mechanism of circ_0005615 in CC remains unclear. The levels of circ_0005615, miR-138-5p, and lysine demethylase 2A (KDM2A) were measured using qRT-PCR or western blot. Cell proliferation was assessed by Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, and colony formation experiments. Cell invasion and migration were tested by transwell assay and wound healing assay. Flow cytometry and Caspase-Glo 3/7 Assay kit were used to analyze cell apoptosis. The expression of proliferation-related and apoptosis-related markers was detected by western blot. The binding relationships among circ_0005615, miR-138-5p, and KDM2A were verified by dual-luciferase reporter assay or RNA immunoprecipitation assay. Xenograft assay was applied to detect the effect of circ_0005615 in vivo. Circ_0005615 and KDM2A were upregulated, while miR-138-5p was downregulated in CC tissues and cells. Circ_0005615 knockdown retarded cell proliferation, migration, and invasion, while promoting apoptosis. Besides, circ_0005615 sponged miR-138-5p, and miR-138-5p could target KDM2A. miR-138-5p inhibitor reversed the regulation of circ_0005615 knockdown on CC cell growth and metastasis, and KDM2A overexpression also abolished the inhibitory effect of miR-138-5p on CC cell growth and metastasis. In addition, we also discovered that circ_0005615 silencing inhibited CC tumor growth in vivo. Circ_0005615 acted as a tumor promoter in CC by regulating the miR-138-5p/KDM2A pathway.     

Suppression of lncRNA NLRP3 inhibits NLRP3-triggered inflammatory responses in early acute lung injury

Acute lung injury (ALI) is a common lung pathology that is accompanied by alveolar macrophage (AM) activation and inflammatory response. This study investigated the role of the long non-coding RNA NONRATT004344 (hereafter named lncRNA NLRP3) in regulating the Nod-like receptor protein 3 (NLRP3)-triggered inflammatory response in early ALI and the underlying mechanism as well. We established LPS-induced ALI models to explore their interactive mechanisms in vitro and in vivo. Luciferase reporter assays were performed to determine that miR-138-5p could bind to lncRNA NLRP3 and NLRP3. We observed increased lncRNA NLRP3 expression, decreased miR-138-5p expression, NLRP3 inflammasome activation, and upregulated caspase-1, IL-1β, and IL-18 expression in the LPS-induced ALI model. Furthermore, lncRNA NLRP3 overexpression activated the NLRP3 inflammasome and promoted IL-1β and IL-18 secretion; the miR-138-5p mimic abolished these effects in vivo and in vitro. Consistently, miR-138-5p inhibition reversed the effects of lncRNA NLRP3 silencing on the expression of NLRP3-related molecules and inhibition of the NLRP3/caspase-1/IL-1β signalling pathway. Mechanistically, lncRNA NLRP3 sponging miR-138-5p facilitated NLRP3 activation through a competitive endogenous RNA (ceRNA) mechanism. In summary, our results suggested that lncRNA NLRP3 binding miR-138-5p promotes NLRP3-triggered inflammatory response via lncRNA NLRP3/miR-138-5p/NLRP3 ceRNA network (ceRNET) and provides insights into the treatment of early ALI.Subject terms: Bacterial infection, Inflammasome     

HOXC13-AS promotes breast cancer cell growth through regulating miR-497-5p/PTEN axis

Dysregulated long noncoding RNAs (lncRNAs) remains to be explored in tumorigenesis. LncRNA HOXC13 antisense RNA (HOXC13-AS) has been found as an oncogene in many cancers; however, the role of HOXC13-AS in breast cancer still elusive. In this study, the HOXC13-AS levels and its role in cell proliferation was first measured by real-time quantitative polymerase chain reaction, Cell Counting Kit-8 assay, and colony formation assay. It showed that HOXC13-AS was increased in breast cancer tissues compared with the adjacent normal tissues and upregulated HOXC13-AS promoted the growth of breast cancer cells. Then, we found that the miR-497-5p levels were downregulated in cancer tissues compared with the adjacent tissues and miR-497-5p suppressed breast cancer cell proliferation. Further study showed that HOXC13-AS could function as a “sponge” for miR-497-5p then suppress miR-497-5p expression. Moreover, we next identified that Phosphatase and Tensin homolog (PTEN) is the target of miR-497-5p. Overexpression of miR-497-5p by chemical mimics decreased the expression of PTEN, while downregulation of miR-497-5p by HOXC13-AS rescued the expression of PTEN. Finally, we showed that HOXC13-AS promoted the proliferation of breast cancer cells and tumor growth through miR-497-5p/PTEN axis in vitro and in vivo. Hence, we conclude that HOXC13-AS, which is significantly upregulated in breast cancers, promoted cell proliferation through the suppressed miR-497-5p and further upregulated PTEN.     

LIN28B/IRS1 axis is targeted by miR-30a-5p and promotes tumor growth in colorectal cancer

Insulin receptor substrate 1 (IRS1) is a potential oncogene that has been implicated in several malignant tumors. However, the regulatory mechanism of IRS1 remains to be investigated. The aim of our current study is to unveil the mechanism by which IRS1 exerts functions in tumorigenesis of colorectal cancer (CRC). The expression level of IRS1 was found to be higher in CRC cells in comparison with the normal cell. To determine the role of IRS1 in regulating CRC cellular processes, loss-of-function assays were designed and carried out in two CRC cell lines. Both in vitro and in vivo functional assays indicated that silencing of IRS1 suppressed CRC cell survival. Based on bioinformatics prediction and mechanism experiments, IRS1 was identified as a downstream target of miR-30a-5p. Furthermore, RNA-binding protein lin-28 homolog B (LIN28B) was determined to be a stabilizer of IRS1 messenger RNA. More importantly, LIN28B also acted as a target of miR-30a-5p.Through rescue assays, we proved that LIN28B-stablized IRS1 mediated miR-30a-5p-mediated CRC cell growth. In conclusion, this study revealed that LIN28B and LIN28B-stablized IRS1 promoted CRC cell growth by cooperating with miR-30a-5p.     

Long non-coding RNA FENDRR restrains the aggressiveness of CRC via regulating miR-18a-5p/ING4 axis

There is increasing evidence has indicated that long non-coding RNAs (lncRNAs) are implicated in the tumorigenesis and development of colorectal cancer (CRC). Nevertheless, the clinical significances and functions of FENDRR in CRC remain unknown. In this study, we reveal that lncRNA FENDRR is downregulated in CRC and negatively correlated with advanced stage and poor clinical outcomes of patient with CRC. Overexpression of FENDRR represses the proliferation, migrate and invasive capacities of CRC cell in vitro, and upregulation of FENDRR inhibits the growth and distant metastatic capacity of CRC cell in vivo. Mechanistically, FENDRR interacts with miRNA-18a-5p (miR-18a-5p) and subsequently regulates the expression of inhibitor of growth 4 (ING4) in CRC cell. Interestingly, ING4 repression or miR-18a-5p rescues FENDRR induced proliferation and aggressive phenotypes inhibition of CRC cell. Altogether, our findings suggest that FENDRR exerts an inhibitory role in CRC by interacting with miR-18a-5p and future increases ING4 expression.     

CircMTO1 suppresses hepatocellular carcinoma progression via the miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling pathway and epithelial-to-mesenchymal transition

CircRNA mitochondrial tRNA translation optimization 1 (circMTO1) functions as a tumor suppressor usually and is related to the progression of many tumors, including hepatocellular carcinoma (HCC). CircMTO1 is downregulated in HCC as compared to adjacent nontumor tissue, which may suppress the HCC progression by certain signal pathways. However, the underlying signal pathway remains largely unknown. The interactions between circMTO1 and miR-541-5p were predicted through bioinformatics analysis and verified using pull-down and dual-luciferase reporter assays. CCK-8, transwell, and apoptosis assays were performed to determine the effect of miR-541-5p on HCC progression. Using bioinformatic analysis, dual-luciferase reporter assay, RT-qPCR, and western blot, ZIC1 was found to be the downstream target gene of miR-541-5p. The regulatory mechanisms of circMTO1, miR-541-5p, and ZIC1 were investigated using in vitro and in vivo rescue experiments. The results depicted that silencing circMTO1 or upregulating miR-541-5p expression facilitated HCC cell proliferation, migration, and invasion and inhibited apoptosis. CircMTO1 silencing upregulated the expression of downstream ZIC1 regulators of the Wnt/β-catenin pathway markers, β-catenin, cyclin D1, c-myc, and the mesenchymal markers N-cadherin, Vimentin, and MMP2, while the epithelial marker E-cadherin was downregulated. MiR-541-5p knockdown had the opposite effect and reversed the effect of circMTO1 silencing on the regulation of downstream ZIC1 regulators. Intratumoral injection of miR-541-5p inhibitor suppressed tumor growth and reversed the effect of circMTO1 silencing on the promotion of tumor growth in HCC. These findings indicated that circMTO1 suppressed HCC progression via the circMTO1/ miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling and epithelial-to-mesenchymal transition, making it a novel therapeutic target. Subject terms: Cancer therapy, Liver cancer, Tumour-suppressor proteins     

microRNA-16-5p-containing exosomes derived from bone marrow-derived mesenchymal stem cells inhibit proliferation,migration, and invasion,while promoting apoptosis of colorectal cancer cells by downregulating ITGA2

Colorectal cancer (CRC) is a form of cancer developing from either the colon or rectum. Nowadays, research supports the functionality of exosome expressing microRNAs (miRNAs) as potential biomarker for various cancers including CRC. This study was performed with the intent of investigating the roles of both bone marrow-derived mesenchymal stem cells (BMSCs) and exosomal miR-16-5p in CRC by regulating integrin α2 (ITGA2). A microarray-based analysis was conducted to screen the CRC-associated differentially expressed genes (DEGs) as well as potential regulatory miRNAs. Next, the role of miR-16-5p in terms of its progression in association with CRC was determined. Subsequently, CRC cells were exposed to exosomes secreted by BMSCs transfected with miR-16-5p, isolated and cocultured with CRC cells in an attempt to identify the role of exosomes. Effects of BMSCs-derived exosomes overexpressing miR-16-5p on biological functions of CRC cells and tumorigenicity were all subsequently detected. Effects of miR-16-5p treated with CRC cells in regard to CRC in vivo were also measured. ITGA2 was overexpressed, while miR-16-5p was poorly expressed in CRC cells and miR-16-5p targeted ITGA2. The in vitro experiments revealed that the BMSCs-derived exosomes overexpressing miR-16-5p inhibited proliferation, migration, and invasion, while simultaneously stimulating the apoptosis of the CRC cells via downregulation of ITGA2. Furthermore, the results of in vivo experiments confirmed that the BMSCs-derived exosomes overexpressing miR-16-5p repressed the tumor growth of CRC. Collectively, BMSCs-derived exosomes overexpressing miR-16-5p restricted the progression of CRC by downregulating ITGA2.     

Aberrantly reduced expression of miR-342-5p contributes to CCND1-associated chronic myeloid leukemia progression and imatinib resistance

Chronic myeloid leukemia (CML) is a myeloproliferative disorder associated with the Philadelphia chromosome, and the current standard of care is the use of tyrosine kinase inhibitors (TKI). However, some patients will not achieve a molecular response and may progress to blast crisis, and the underlying mechanisms remain to be clarified. In this study, next-generation sequencing was used to explore endogenous miRNAs in CML patients versus healthy volunteers, and miR-342-5p was identified as the primary target. We found that miR-342-5p was downregulated in CML patients and had a significant inhibitory effect on cell proliferation in CML. Through a luciferase reporter system, miR-342-5p was reported to target the 3’-UTR domain of CCND1 and downregulated its expression. Furthermore, overexpression of miR-342-5p enhanced imatinib-induced DNA double-strand breaks and apoptosis. Finally, by analyzing clinical databases, we further confirmed that miR-342-5p was associated with predicted molecular responses in CML patients. In conclusion, we found that both in vivo and in vitro experiments and database cohorts showed that miR-342-5p plays a key role in CML patients, indicating that miR-342-5p may be a potential target for future CML treatment or prognostic evaluation.Subject terms: Chronic myeloid leukaemia, Oncogenes     

microRNA-16-5p suppresses cell proliferation and angiogenesis in colorectal cancer by negatively regulating forkhead box K1 to block the PI3K/Akt/mTOR pathway

MicroRNAs (miRNAs/miRs) have aroused increasing attention in colorectal cancer (CRC) therapy. This study is designed for a detailed analysis of the roles of miR-16-5p and forkhead box K1 (FOXK1) in cell angiogenesis and proliferation during CRC in addition to their underlying mechanisms. CRC tissues and colon cancer cell lines (SW620 and HCT8) were investigated. qRT-PCR and Western blot were utilized to evaluate miR-16-5p and FOXK1 expression. Following gain- and loss-of-function assays on miR-16-5p or FOXK1, the effects of miR-16-5p and FOXK1 were assessed on cell angiogenesis and proliferation in CRC cells. A dual-luciferase reporter assay was employed to evaluate the binding relationship of miR-16-5p and FOXK1. Western blot was used to determine the effects of miR-16-5p and FOXK1 on key molecules of the PI3K/Akt/mTOR pathway. Highly expressed FOXK1 and lowly expressed miR-16-5p were observed in CRC cells and tissues. miR-16-5p overexpression or FOXK1 knockdown reduced CRC cell proliferation and angiogenesis of human umbilical vein endothelial cells co-cultured with the supernatant of CRC cells, whereas miR-16-5p silencing or FOXK1 upregulation caused opposite trends. Additionally, miR-16-5p negatively modulated FOXK1 expression. The blockade of the PI3K/Akt/mTOR pathway was triggered by miR-16-5p overexpression or FOXK1 silencing. In conclusion, miR-16-5p hampers cell angiogenesis and proliferation during CRC by targeting FOXK1 to block the PI3K/Akt/mTOR pathway.Key words: microRNA-16-5p, forkhead box K1, PI3K/Akt/mTOR pathway, colorectal cancer, proliferation, angiogenesis     

RBP-J promotes cell growth and metastasis through regulating miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis in colorectal cancer

BackgroundRBP-J is involved in number of cellular processes. However, the potential mechanisms of RBP-J on colorectal cancer (CRC) development have not been clearly defined. In this study, we aimed to investigate the role and molecular mechanism of RBP-J in CRC.MethodsThe expression levels of RBP-J and Tiam1 in CRC tissues and cells were evaluated by RT-qPCR or western blot. RBP-J was knocked down with sh-RBP-J or overexpressed by pcDNA3.1-RBP-J in CRC cells. Cell proliferation, migration and invasion abilities were analyzed by MTT, wound healing, and transwell assay, respectively. CHIP-qPCR, RIP and dual luciferase reporter assays were performed to confirm the interaction between miR-182-5p and RBP-J or Tiam1. Expression levels of p-p38 MAPK, p38 MAPK, Slug-1, Twist1 and MMP-9 were analyzed by western blot. G-LISA test was used to detect Rac1 activity.ResultsOur results showed that the expression of RBP-J and Tiam1 was significantly up-regulated in CRC tissues and cells. RBP-J overexpression promoted proliferation, migration and invasion of CRC cells. Moreover, RBP-J was found to directly target miR-182-5p promoter and positively regulate the Tiam1/Rac1/p38 MAPK signaling pathway in CRC cells. It was also proved that miR-182-5p can bind Tiam1 directly. Furthermore, experiments revealed that RBP-J could promote CRC cell proliferation, migration and invasion via miR-182-5p-mediated Tiam1/Rac1/p38 MAPK axis. In addition, knockdown of RBP-J reduced tumor growth and metastasis in CRC mice.ConclusionRBP-J regulates CRC cell growth and metastasis through miR-182-5p mediated Tiam1/Rac1/p38 MAPK signaling pathway, implying potential novel therapeutic targets for CRC patients.     

MiR-330-3p suppresses phosphoglycerate mutase family member 5 -inducted mitophagy to alleviate hepatic ischemia-reperfusion injury

Mitochondrial dysfunction plays a central role in hepatic ischemia-reperfusion injury (IRI). The significance of mitophagy in hepatic IRI remains poorly understood. The mechanisms that cause IRI are complex, and many factors are involved in the injury formation process. The miR-330-3p mediates cell proliferation, cell death, and metabolism in various organisms. In this study, the levels of miR-330-3p were significantly downregulated in hepatic IRI, and the number of autophagosomes was increased in response to IRI as obtained under both in vivo and in vitro conditions. These results demonstrate that a reduction in miR-330-3p expression represents an important factor involved with promoting hepatic IRI. Moreover, we found that miR-330-3p interacted with phosphoglycerate mutase family member 5 (PGAM5) to regulate mitophagy. In specific, an overexpression of miR-330-3p diminished PGAM5 levels, which promoted mitophagy in response to IRI. In contrast, a downregulation of miR-330-3p was associated with increased PGAM5 levels leading to increased mitophagy. In conclusion, miR-330-3p suppresses PGAM5-induced mitophagy to alleviate hepatic IRI. Such findings not only reveal some of the mechanistic basis for this microRNA in liver injury, but also provide a foundation for new therapeutic approaches in the treatment of this condition.     

circEVI5 acts as a miR-4793-3p sponge to suppress the proliferation of gastric cancer

Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs (ncRNAs) with a covalently closed loop structure. Accumulating evidence shows that circRNAs play vital roles in the growth, metastasis, treatment and prognosis of various cancers. However, the detailed functions and underlying mechanisms of circEVI5 (hsa_circ_0013162) in gastric cancer (GC) remain undocumented. In this study, the expression levels and prognostic value of circEVI5 were validated in GC tissue samples by using qRT-PCR. circEVI5 was significantly downregulated in GC tissues and cells, and low circEVI5 expression was correlated with poor prognosis. Next, in vitro CCK-8 assay, EdU incorporation assay, PI staining cell cycle assay, and in vivo xenograft mouse models were conducted to assess the functions of circEVI5. Gain of function experiments indicated that circEVI5 could inhibit GC cell proliferation and retard the cell cycle. Moreover, bioinformatics prediction showed that circEVI5 binds to miR-4793-3p, while FOXO1 may be a target of miR-4793-3p. Pull-down assays, RNA immunoprecipitation (RIP) assays, luciferase assays, and western blot were used to confirm the interactions between circEVI5, miR-4793-3p, and FOXO1. Functional assays demonstrated that circEVI5 suppressed the proliferation of GC by sponging miR-4793-3p and increasing FOXO1 expression levels. In conclusion, our study demonstrated that circEVI5 can bind miR-4793-3p as a ceRNA to eliminate the negative regulation of FOXO1, therefore suppressing GC proliferation.Subject terms: Gastric cancer, Oncogenesis