MicroRNA-340-5p modulates cisplatin resistance by targeting LPAATβ in osteosarcoma

Deciphering chemoresistance in osteosarcoma: Unveiling regulatory mechanisms and function through the lens of noncoding RNA

Osteosarcoma (OS) is a primary malignant bone tumor and is prevalent in children, adolescents, and elderly individuals. It has the characteristics of high invasion and metastasis. Neoadjuvant chemotherapy combined with surgical resection is the most commonly used treatment for OS. However, the efficacy of OS is considerably diminished by chemotherapy resistance. In recent years, noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, are hot topics in the field of chemotherapy resistance research. Several studies have demonstrated that ncRNAs are substantially associated with chemoresistance in OS. Thus, the present study overviews the abnormally expressed ncRNAs in OS and the molecular mechanisms involved in chemoresistance, with an emphasis on their function in promoting or inhibiting chemoresistance. ncRNAs are expected to become potential therapeutic targets for overcoming drug resistance and predictive biomarkers in OS, which are of great significance for enhancing the therapeutic effect and improving the prognosis.

MicroRNAs as the pivotal regulators of cisplatin resistance in osteosarcoma

Osteosarcoma (OS) is an aggressive bone tumor that originates from mesenchymal cells. It is considered as the eighth most frequent childhood cancer that mainly affects the tibia and femur among the teenagers and young adults. OS can be usually diagnosed by a combination of MRI and surgical biopsy. The intra-arterial cisplatin (CDDP) and Adriamycin is one of the methods of choices for the OS treatment. CDDP induces tumor cell death by disturbing the DNA replication. Although, CDDP has a critical role in improving the clinical complication in OS patients, a high ratio of CDDP resistance is observed among these patients. Prolonged CDDP administrations have also serious side effects in normal tissues and organs. Therefore, the molecular mechanisms of CDDP resistance should be clarified to define the novel therapeutic modalities in OS. Multidrug resistance (MDR) can be caused by various cellular and molecular processes such as drug efflux, detoxification, and signaling pathways. MicroRNAs (miRNAs) are the key regulators of CDDP response by the post transcriptional regulation of target genes involved in MDR. In the present review we have discussed all of the miRNAs associated with CDDP response in OS cells. It was observed that the majority of reported miRNAs increased CDDP sensitivity in OS cells through the regulation of signaling pathways, apoptosis, transporters, and autophagy. This review highlights the miRNAs as reliable non-invasive markers for the prediction of CDDP response in OS patients.

Lysophosphatidic Acid Signaling and microRNAs: New Roles in Various Cancers

A wide range of microRNAs (miRNAs) are coded for in the human genome and contribute to the regulation of gene expression. MiRNAs are able to degrade mRNAs and/or prevent the RNA transcript from being translated through complementary binding of the miRNA seed region (nucleotide 2-8) to the 3’-untranslated regions of many mRNAs. Although miRNAs are involved in almost all processes of normal human cells, they are also involved in the abnormal functions of cancer cells. MiRNAs can play dual regulatory roles in cancer, acting either as tumor suppressors or as tumor promoters, depending on the target, tumor type, and stage. In the current review, we discuss the present status of miRNA modulation in the setting of lysophosphatidic acid (LPA) signaling. LPA is produced from lysophosphatidylcholine by the enzyme autotaxin and signals via a range of G protein-coupled receptors to affect cellular processes, which ultimately causes changes in cell morphology, survival, proliferation, differentiation, migration, and adhesion. Several studies have identified miRNAs that are over-expressed in response to stimulation by LPA, but their functional roles have not yet been fully clarified. Since RNA-based treatments hold tremendous promise in the area of personalized medicne, many efforts have been made to bring miRNAs into clinical trials, and this field is evolving at an increasing pace.

Lipid Metabolism in Cancer: The Role of Acylglycerolphosphate Acyltransferases (AGPATs)

Simple Summary

Rapidly proliferating cancer cells reprogram lipid metabolism to keep the balance between fatty acid uptake, synthesis, consumption, and storage as triacylglycerides (TAG). Acylglycerolphosphate acyltransferases (AGPATs)/lysophosphatidic acid acyltransferases (LPAATs) are a family of enzymes that catalyze the synthesis of phosphatidic acid (PA), an intermediate in TAG synthesis, a signaling molecule, and a precursor of phospholipids. Importantly, the expression of AGPATs has been linked to diverse physiological and pathological phenotypes, including cancer. In this review, we present an overview of lipid metabolism reprogramming in cancer cells and give insight into the expression of AGPAT isoforms as well as their association with cancers, parameters of tumor biology, patient classification, and prognosis.

Abstract

Altered lipid metabolism is an emerging hallmark of aggressive tumors, as rapidly proliferating cancer cells reprogram fatty acid (FA) uptake, synthesis, storage, and usage to meet their increased energy demands. Central to these adaptive changes, is the conversion of excess FA to neutral triacylglycerides (TAG) and their storage in lipid droplets (LDs). Acylglycerolphosphate acyltransferases (AGPATs), also known as lysophosphatidic acid acyltransferases (LPAATs), are a family of five enzymes that catalyze the conversion of lysophosphatidic acid (LPA) to phosphatidic acid (PA), the second step of the TAG biosynthesis pathway. PA, apart from its role as an intermediate in TAG synthesis, is also a precursor of glycerophospholipids and a cell signaling molecule. Although the different AGPAT isoforms catalyze the same reaction, they appear to have unique non-overlapping roles possibly determined by their distinct tissue expression and substrate specificity. This is best exemplified by the role of AGPAT2 in the development of type 1 congenital generalized lipodystrophy (CGL) and is also manifested by recent studies highlighting the involvement of AGPATs in the physiology and pathology of various tissues and organs. Importantly, AGPAT isoform expression has been shown to enhance proliferation and chemoresistance of cancer cells and correlates with increased risk of tumor development or aggressive phenotypes of several types of tumors.

Research Progress of MicroRNA in Chemotherapy Resistance of Osteosarcoma

Osteosarcoma (OS) is a malignant tumor prevalent in adolescents; however, a clinically effective treatment for this malignancy is lacking. The lack of effective treatment methods and factors, such as recurrence and drug resistance, further dampen the prospect of clinically treating OS. In recent years, small molecule microRNAs (miRNAs) with a length of approximately 20-24 nucleotides have gradually attracted the attention of the medical community. Studies have found that miRNAs can regulate the cell cycle, apoptosis, cell proliferation, and cell proliferation. The metabolic response of cancer cells, invasion and metastasis of cancer cells, and angiogenesis play an important role in the process of tumorigenesis. miRNAs regulate gene expression by regulating mRNA expression after transcription. A large amount of data from many studies indicate that they have diagnostic and prognostic biomarker effects in OS and are involved in regulating the metabolism of cancer cells and resistance or sensitivity to chemotherapy drugs. Chemotherapy resistance is one of the most critical problems in clinically treating OS. A large number of basic studies and systematic summaries are required to provide a theoretical basis for elucidating the mechanism and drug development of chemotherapeutic agents. Therefore, this article discusses the role of miRNAs in OS resistance. Herein, the related research progress of the studies is reviewed to provide more useful information for the development of effective therapy.

Circular RNA circ-CHI3L1.2 modulates cisplatin resistance of osteosarcoma cells via the miR-340-5p/LPAATβ axis

Resistance to chemotherapy drugs is a major factor affecting the surgical outcome and prognosis of osteosarcoma patients. Circular RNAs (circRNAs) play an important role in tumor resistance to chemotherapy. In the present study, we aimed to investigate the role and mechanism of circRNA circ-chitinase 3-like 1.2 (CHI3L1.2) in resistance to cisplatin chemotherapy in osteosarcoma. We found that circ-CHI3L1.2 levels were higher in cisplatin-resistant cells than in their parent cells. circ-CHI3L1.2 knockdown decreased the half-maximal inhibitory concentration (IC₅₀) of cisplatin and the expression levels of P-glycoprotein (P-gp), multidrug-resistance protein 1 (MRP1), and glutathione-S-transferase Pi1 (GSTP1), and promoted apoptosis of cisplatin-resistant osteosarcoma cells. In addition, circ-CHI3L1.2 knockdown induced mesenchymal to epithelial transition (MET) and suppressed cell migration and invasion. The competitive endogenous RNA (ceRNA) mechanism indicated that circ-CHI3L1.2 targets the micro-RNA (miR)-340-5p-lysophosphatidic acid acyltransferase β (LPAATβ) axis, and inhibition of miR-340-5p alleviates the effect of circ-CHI3L1.2 knockdown. In conclusion, circ-CHI3L1.2 levels were increased in cisplatin-resistant osteosarcoma cells and circ-CHI3L1.2 knockdown sensitized cisplatin-resistant osteosarcoma cells to cisplatin through the miR-340-5p-LPAATβ axis.

LncRNA RUSC1-AS1 promotes osteosarcoma progression through regulating the miR-340-5p and PI3K/AKT pathway

Dysregulation of long noncoding RNA (lncRNA) is frequently involved in the progression and development of osteosarcoma. LncRNA RUSC1-AS1 is reported to be upregulated and acts as an oncogene in hepatocellular carcinoma, cervical cancer and breast cancer. However, its role in osteosarcoma has not been studied yet. In the present study, we investigated the role of RUSC1-AS1 in osteosarcoma both in vitro and in vivo. The results showed that the expression of RUSC1-AS1 was significantly upregulated in osteosarcoma cell line U2OS and HOS compared to that in human osteoblast cell line hFOB1.19. Similar results were found in human samples. Silencing RUSC1-AS1 by siRNA significantly inhibited U2OS and HOS cell proliferation and invasion, measured by CCK-8 and transwell assay. Besides, knockdown of RUSC1-AS1 increased cell apoptosis in osteosarcoma cell lines. In addition, RUSC1-AS1 promoted the epithelial-mesenchymal transition (EMT) process of osteosarcoma cells. In vivo experiments confirmed that RUSC1-AS1 knockdown had an inhibitory effect on osteosarcoma tumor growth. Mechanically, we showed that RUSC1-AS1 directly binds to and inhibits miR-340-5p and activates the PI3K/AKT signaling pathway. In conclusion, our study demonstrated that RUSC1-AS1 promoted osteosarcoma development both in vitro and in vivo through sponging to miR-340-5p and activating the PI3K/AKT signaling pathway. Therefore, RUSC1-AS1 becomes a potential therapeutic target for osteosarcoma.

Knockdown of microRNA-203 reduces cisplatin chemo-sensitivity to osteosarcoma cell lines MG63 and U2OS in vitro by targeting RUNX2

Clinical studies have reported that miRNAs abnormal expression are associated with the generation of cisplatin-resistant to osteosarcoma. Our previous research found that miR-203 is downregulated in osteosarcoma cells and overexpressed miR-203 exerts antitumor properties on osteosarcoma cells. However, the role and mechanism of miR-203 in regulating the sensitivity of cisplatin in osteosarcoma cells remains unclear. This study aimed to investigate the effects of miR-203 in cisplatin therapy for osteosarcoma cells in vitro and determined the underlying mechanism. In this study, we found that miR-203 was significantly upregulated in osteosarcoma cells after exposure to cisplatin. miR-203 knockdown reduced the sensitivity of osteosarcoma cells to cisplatin by suppressing cell apoptosis, cell cycle arrest, and inducing invasion. Meanwhile, we found that miR-203 knockdown reduces the therapeutic sensitivity of osteosarcoma cells by upregulating RUNX2. Moreover, we found that RUNX2 silencing sensitizes osteosarcoma cells to chemotherapy treatment of cisplatin. In summary, our findings demonstrated that miR-203 knockdown reduces cisplatin chemo-sensitivity to osteosarcoma cells in vitro by targeting RUNX2, and speculated that miR-203 may be a target for drug resistance of osteosarcoma to cisplatin.

Fertility preservation in women with ovarian cancer: Finding new pathways: A case-control study

Background

Surgery and chemotherapy are the two most common treatments for cancers, including ovarian cancer. Although most ovarian cancers occur over the age of 45 yr, it may involve younger women and affect their reproductive ability.

Objective

To assess the expression of Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), Forkhead Box O1 (FOXO1), and miR-340 genes in the ovarian cancer tissues as well as ovarian cancer cell lines.

Materials and Methods

In this case-control study, 30 ovarian cancer samples (with the average age of 37 ± 2.5 years) coupled with their non-tumor marginal tissue (as a control) were collected. Proliferated cell lines were treated with several concentrations of cisplatin, and the half maximal inhibitory concentration (IC50) of cisplatin was quantified by MTT-assay. After RNA extraction, cDNA synthesis and qRT-PCR were done. Finally, the results were analyzed.

Results

While the expression levels of miR-340 and FOXO1 genes in tumor samples displayed a significant reduction (p ≤ 0.001), the LGR5 gene presented a significant increase in expression (p ≤ 0.0001). However, conversely, the expression levels of miR-340 and FOXO1 genes in cisplatin-sensitive cell lines, after 24, 48, and 72 hr of cisplatin treatment, indicated a significant increase (p ≤ 0.001) while the expression of LGR5 gene showed a significant decrease in the cisplatin-sensitive cell line (p < 0.05).

Conclusion

The LGR5, FOXO1, and miR-340 genes can be targeted for early diagnosis and more accurate treatment of ovarian cancer and may prevent some of the ovarian cancer complications such as infertility.

Noncoding RNAs in osteosarcoma: Implications for drug resistance

Osteosarcoma is the most frequent bone malignancy in children and adolescents. Despite advances of surgery and chemotherapy in osteosarcoma over the past decades, overall survival rates of osteosarcoma have reached a plateau. The development of multi-drug resistance (MDR) has become the main obstacle in improving chemotherapeutic effects in osteosarcoma treatment. Therefore, understanding detailed mechanisms of chemoresistance and developing novel therapeutic targets to overcome chemoresistance are crucial to improve the prognosis of osteosarcoma patients. Accumulating evidence has proved that multiple noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) play pivotal roles in osteosarcoma progression. Notably, a great number of ncRNAs are abnormally expressed and can regulate chemosensitivity through various mechanisms in osteosarcoma. In this review, we systematically summarize the roles of ncRNAs as well as the molecular mechanisms in modulating drug resistance of osteosarcoma and discuss the potential roles of ncRNAs as biomarkers and novel therapeutic targets for osteosarcoma.

miR-340: A multifunctional role in human malignant diseases

MicroRNAs (miRNAs) are a class of short non-coding RNAs of approximately 22 nucleotides in length, which function by binding to the 3' UTR sequences of their target mRNAs. It has been reported that dysregulated miRNAs play pivotal roles in numerous diseases, including cancers, such as gastric, breast, colorectal, ovarian, and other cancers. Recent research efforts have been devoted to translating these basic discoveries into clinical applications that could improve the therapeutic outcome in patients with cancer. Early studies have shown that miR-340 may act either as an oncogene or a tumor suppressor by targeting genes related to proliferation, apoptosis, and metastasis, as well as those associated with diagnosis, treatment, chemoresistance, and prognosis. miR-340 has been shown to have a role in other diseases, such as autoimmune diseases, acute stroke, and alcoholic steatohepatitis. Nevertheless, the roles of miR-340 in human malignancies are still unclear, and the associated mechanisms are complex, involving a variety of signaling pathways, such as Wnt/β-catenin and the JAK-STAT pathways. Herein, we review the crucial roles of miR-340 in human cancers through the analysis of the latest research studies, with the aim of clarifying miR-340 function in malignant disease diagnosis, treatment, and prognosis, and to propose further investigations.

MicroRNA-340-5p suppressed rheumatoid arthritis synovial fibroblast proliferation and induces apoptotic cell number by targeting signal transducers and activators of transcription 3

Rheumatoid arthritis is a chronic systemic autoimmune disease. In this study, the role of microRNA-340-5p in rheumatoid arthritis was investigated. qRT-PCR was used to detect the expression of microRNA-340-5p in serums, synovial tissues, and fibroblast-like synoviocytes from patients and healthy participants. Cell proliferation rate, cell cycle and apoptotic cell numbers were measured by CCK-8 and flow cytometry assays. The expression of pro-inflammation factors was determined by ELISA. Our data showed that the expression of microRNA-340-5p was greatly suppressed in rheumatoid arthritis serums, synovial tissues and rheumatoid arthritis-fibroblast-like synoviocytes compared to that in healthy controls. Over-expression of microRNA-340-5p greatly suppressed cell proliferation, promoted cell apoptosis, and suppressed the expression of inflammation factors in rheumatoid arthritis fibroblast-like synoviocytes. Additionally, STAT3 was a target of microRNA-340-5. Overexpression of STAT3 could reverse the outcome of microRNA-340-5p on cell proliferation and apoptosis in rheumatoid arthritis fibroblast-like synoviocytes. The findings in our study demonstrated that microRNA-340-5p may serve as a potential target for therapeutic direction for patients with rheumatoid arthritis.

Effect of miR-26b-5p on cis-diamine dichloroplatinum-induced ovarian granulosa cell injury by targeting MAP3K9

The proliferation and differentiation of granulosa cells are very important for follicular development. The dysfunction of granulosa cells leading to follicular development is an important cause of ovarian endocrine abnormalities. More and more evidence shows that microRNAs are involved in the regulation of ovarian granulosa cell function. It has been found that MiR-26b may be involved in CDDP resistance. Studies have shown that miR-26b can promote apoptosis of ovarian granulosa cells, but there are few studies on its mechanism, and no studies have been found on the damage of miR-26b-5p to rat ovarian granulosa cells induced by CDDP. Identification of ovarian granulosa cells was conducted by immunochemical staining. Cell counting kit 8 (CCK-8) was used to detect cell viability, flow cytometry was used to detect cell apoptosis, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot (WB) were used to analyze the expression of miR-26b-5p, MAP3K9, cleaved Caspase-3, Bax, and Bcl-2; dual-luciferase reporter assay results further verify the targeting relation between miR-26b-5p and MAP3K9. CDDP remarkably inhibited ovarian granulosa cell viability and induced ovarian granulosa cell apoptosis; miR-26b-5p inhibitor enhanced viability and inhibited apoptosis of ovarian granulosa cells, which treated with CDDP, but had little effect on normal cells. MAP3K9 partially reversed the effect of miR-26b-5p on ovarian granulosa cells induced by CDDP. miR-26b-5p has a protective effect on CDDP-induced ovarian granulosa cells via targeting MAP3K9.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

LncRNA HAND2-AS1 exerts anti-oncogenic effects on ovarian cancer via restoration of BCL2L11 as a sponge of microRNA-340-5p

In the early stage of ovarian cancer (OC), molecular biomarkers are critical for its diagnosis and treatment. Nevertheless, there is little research on the mechanism underlying tumorigenesis in OC. Herein, we aimed to explore whether long noncoding RNA (lncRNA) HAND2-AS1 participated in the regulation of the cell proliferation, migration, and apoptosis of OC by regulating B-cell lymphoma 2 like 11 (BCL2L11) and microRNA-340-5p (miR-340-5p). Differentially expressed lncRNAs in OC were screened by microarray-based analysis. HAND2-AS1, BCL2L11, and miR-340-5p expression was assessed in normal ovarian and OC tissues and human OC cell lines. Then, the relationships among HAND2-AS1, BCL2L11, and miR-340-5p were explored. Ectopic expression and depletion experiments were applied to analyze the effects of HAND2-AS1, miR-340-5p and BCL2L11 on migration, invasion, and proliferation of OC cells, as well as apoptosis. Lastly, the tumor xenograft in nude mice was conducted to test the tumorigenesis in vivo. In silico analysis displayed poor expression of HAND2-AS1 in OC. HAND2-AS1 specifically sponged with miR-340-5p which was found to directly target BCL2L11. Importantly, HAND2-AS1 or BCL2L11 overexpression or miR-340-5p downregulation resulted in reduction of cell invasion and migration, together with decrease of cell proliferation and increase of cell apoptosis in OC. Besides, high-expressed HAND2-AS1 inhibited the tumorigenesis in nude mice. To sum up, these data suggests HAND2-AS1 as an anti-oncogene in OC through upregulation of BCL2L11 by competitively binding to miR-340-5p, which demonstrates that there are potential diagnosis and therapy values of HAND2-AS1 in OC.

MicroRNA-340-5p suppresses non-small cell lung cancer cell growth and metastasis by targeting ZNF503

Background

MicroRNAs (miRNAs) have been reported to play crucial roles in cancer cell processes, including proliferation, metastasis and cell cycle progression. We aimed to identify miRNAs that could act as suppressors of cell growth and invasion in non-small cell lung cancer (NSCLC).

Methods

Fifteen paired NSCLC tissue samples and pericarcinomatous normal tissues were collected and preserved in liquid nitrogen. The expression levels of miR-340-5p and ZNF503 mRNA were detected using a qPCR assay. The transfection of plasmids was conducted using Lipofectamine 3000 according to the manufacturer’s protocol. Cell proliferation was determined using a CCK-8 assay. The protein levels of endothelial–mesenchymal transition markers were measured using a western blot assay. Cell invasive ability was evaluated using a transwell assay. TargetScan was used to predict targets of miR-340. A dual luciferase reporter assay was performed to confirm a potential direct interaction between miR-340-5p and ZNF503.

Results

The expression level of miR-340-5p was frequently found to be lower in NSCLC tissues than in matched pericarcinomatous normal tissues. Overexpression of miR-340-5p significantly inhibited the proliferation and invasion NCI-H1650 (a NSCLC cell line), while inhibition of miR-340-5p stimulated cell growth. Using TargetScan, we predicted that ZNF503 could be a target of miR-340-5p. Further mechanistic studies demonstrated that the forced expression of ZNF503 could partially abrogate the miR-340-5p-mediated decrease in NCI-H1650 cell viability and invasion, suggesting that miR-340-5p suppressed cell growth and invasion in a ZNF503-dependent manner.

Conclusion

Our findings indicate that miR-340-5p inhibits NCI-H1650 cell proliferation and invasion by directly targeting ZNF503 and that miR-340-5p can serve as a potential therapeutic target for treating NSCLC.

Electronic supplementary material

The online version of this article (10.1186/s11658-019-0161-1) contains supplementary material, which is available to authorized users.

miR-340 alleviates chemoresistance of osteosarcoma cells by targeting ZEB1

Chemoresistance during treatment of osteosarcoma (OS) is attracting more and more attention as the main clinical obstacle. The purpose of this study was to elucidate the role of miR-340 in chemoresistance of OS. Plasmid construction and transfection, miRNA arrays, PCR analyses, and western blot analysis, as well as MTT, apoptosis, and luciferase assays were carried out in MG-63 cells and MG-63/cisplatin (DDP)-resistant cells. The results showed that miR-340 was downregulated in OS tissues and drug-resistant OS cells. Moreover, a negative correlation was observed between miR-340 and ZEB1 expression in OS tissues. Forced expression of miR-340 in drug-resistant OS cells significantly reduced multidrug resistance-1 and P-gp expression. Overexpression of miR-340 enhanced sensitivity to DDP by inhibiting viability and promoting apoptosis. The luciferase assay and western blot analysis identified ZEB1 as a direct target of miR-340, and miR-340 negatively regulated ZEB1 expression. Ectopic expression of ZEB1 reversed the effects of miR-340 on P-gp expression, cell viability, and apoptosis. miR-340 alleviated chemoresistance of OS cells by targeting ZEB1. Our results indicate that targeting miR-340 may be a potential therapeutic approach to treat drug-resistant OS.

High serum CRP influences myocardial miRNA profiles in ischemia-reperfusion injury of rat heart

Objective

Prognosis of myocardial infarction tends to be worse when serum C-reactive protein (CRP) level is high. miRNAs are also known to be involved in different pathogeneses of heart diseases such as myocardial infarction. However, how CRP is involved in myocardial infarction has not been fully elucidated. We hypothesized that serum CRP changes the miRNA profile during ischemia-reperfusion injury (IRI) of the myocardium. To confirm this hypothesis, we performed global miRNA expression profiling of myocardium using IRI and CRP infusion rat model.

Methods

After ligation of the coronary artery of rat hearts, human serum CRP was intravenously injected, and reperfusion was performed (I/R+CRP group, n = 6). Control group consisted of the sham group (n = 3), IV CRP infusion group (CRP only, n = 3), and the I/R-only group (I/R only, n = 5). We evaluated 423 miRNA expression in non-ischemic areas and areas at risk (AAR) of each group using NanoString nCounter miRNA expression assay.

Results

MiR-124 was downregulated in non-ischemic myocardium in CRP-only group. In AAR, 7 miRNAs were commonly upregulated in both I/R-only and I/R+CRP groups. And additional 6 miRNAs were upregulated in the I/R+CRP group (miR-33, miR-409-3p, miR-384-3p, miR-3562, miR-101a, and miR-340-5p). Similarly, in the non-ischemic areas, 6 miRNAs were commonly upregulated in both I/R-only and I/R+CRP groups, and additional 5 miRNAs changed in the I/R+CRP group (upregulation of miR-3559-5p, miR-499, and miR-21 and downregulation of miR-500 and miR-532-3p).

Conclusion

We showed that when serum CRP level is high, IRI results in multiple miRNA profile changes not only in ischemic areas but also in non-ischemic myocardium. Our results may provide a strong basis for studying the role of CRP and miRNAs in ischemic heart disease.

miR‑210‑3p regulates cell growth and affects cisplatin sensitivity in human ovarian cancer cells via targeting E2F3

The potential role of microRNA (miR)‑210‑3p in carcinogenesis and the cisplatin sensitivity of ovarian cancer were evaluated in the present study. The relative expression levels of miR‑210‑3p in cisplatin‑sensitive SKOV‑3 cells and cisplatin‑resistant SKOV‑3/DDP cells were determined using reverse transcription‑quantitative polymerase chain reaction analysis. miR‑210‑3p mimics and inhibitors were transfected into SKOV‑3/DDP cells. Cell Counting Kit‑8, scratch and Transwell invasion assays and flow cytometry were conducted to evaluate the role of miR‑210‑3p in ovarian cancer cells. A luciferase reporter assay was used to verify the association between miR‑210‑3p and E2F transcription factor 3 (E2F3). Drug sensitivity was evaluated by treating the cells with cisplatin. The expression level of miR‑210‑3p was lower in SKOV‑3/DDP cells than in SKOV‑3 cells. Compared with the untransfected control, SKOV‑3 cells transfected with miR‑210‑3p exhibited a significantly higher survival rate. The overexpression of miR‑210‑3p inhibited SKOV‑3/DDP cell proliferation, migration and invasion, and promoted cell apoptosis. By contrast, the inhibition of miR‑210‑3p promoted cell migration and invasion. The luciferase reporter assay confirmed that E2F3 was a direct target gene of miR‑210‑3p. Cisplatin treatment resulted in a sharp decrease in the survival rate of SKOV‑3/DDP cells transfected with the miR‑210‑3p mimics. The decrease in cell survival rate caused by the overexpression of miR‑210‑3p was rescued by the overexpression of E2F3 in SKOV‑3/DDP cells. Taken together, these results suggest that miR‑210‑3p may act as a tumor suppressor in ovarian cancer cells and affect the sensitivity of cells to cisplatin by directly targeting E2F3. This indicates its potential use as a therapeutic target for improving drug resistance in ovarian cancer.

MicroRNA-340-5p relieved chronic constriction injury-induced neuropathic pain by targeting Rap1A in rat model

OBJECTIVES

Neuropathic pain (NP) is one of the main challenges towards NP syndrome treatment. miR-340-5p exhibit different expression levels in NP models. Its effects on NP remained unclear. The objective of this study was to explore the potential regulation mechanisms of miR-340-5p in NP.

METHODS

Rat model of chronic constriction injury (CCI) was established to induce NP in vivo. NP levels were assessed using mechanical withdrawal threshold (MWT). The inflammation response in CCI rats were determined by HE staining and ELISA assay. The target genes of miR-340-5p were verified by luciferase report assays.

RESULTS

In CCI rats, level of miR-340-5p was down-regulated both in spinal cord tissues and isolated microglial cells. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were decreased in CCI rats, which were restored upon miR-340-5p overexpression. miR-340-5p overexpression also decreased inflammation as well as expression levels of COX-2, IL-1β, TNF-α and IL-6 in CCI rats. Luciferase report assays revealed Rap1A was a target gene of miR-340-5p in the experimental model. Elevated miR-340-5p decreased Rap1A expression level in vitro and in vivo. Overexpression of Rap1A protein restored expression levels of COX-2, IL-1β, TNF-α and IL-6, reduced the PWT and PWL and increased inflammation response in CCI rats.

CONCLUSION

miR-340-5p alleviated CCI-induced NP by targeting Rap1A. miR-340-5p and Rap1A may be the potential treatment targets for NP therapeutics.

Long noncoding RNA OIP5-AS1 causes cisplatin resistance in osteosarcoma through inducing the LPAATβ/PI3K/AKT/mTOR signaling pathway by sponging the miR-340-5p

The abnormal expression of long noncoding RNAs (lncRNAs) plays an important role in the regulation of human cancer progression and drug resistance. The lncRNA OPI5-AS1 is a crucial regulator in some cancers; however, its role in cisplatin resistance of osteosarcoma remains unclear. We found that OIP5-AS1 was significantly upregulated in cisplatin-resistant (CR) osteosarcoma cells MG63-CR and SaOS2-CR compared with the corresponding parental cells. OIP5-AS1 silencing suppressed cell growth in vitro and in vivo, and promoted apoptosis of MG63-CR and SaOS2-CR cells, indicating that knockdown of OIP5-AS1 significantly decreased cisplatin resistance in MG63-CR and SaOS2-CR cells. This conclusion was supported by the decreased expression of the drug resistance-related factors multidrug resistance-associated protein 1 (MRP1) and P-glycoprotein (P-gp) upon OIP5-AS1 silencing. In addition, OIP5-AS1 downregulation suppressed the PI3K/AKT/mTOR signaling pathway. Importantly, we demonstrated that OIP5-AS1 functions as a competing endogenous RNA of miR-340-5p and regulates the expression of lysophosphatidic acid acyltransferase (LPAATβ), which is a target of miR-340-5p. Moreover, downregulation of miR-340-5p partly reversed the inhibitory effect of OIP5-AS1 knockdown on the PI3K/AKT/mTOR pathway and therefore counteracted cisplatin resistance in MG63-CR and SaOS2-CR cells. In conclusion, OIP5-AS1 causes cisplatin resistance in osteosarcoma through inducing the LPAATβ/PI3K/AKT/mTOR signaling pathway by sponging the miR-340-5p. Our results contribute to a better understanding of the function and mechanism of OIP5-AS1 in osteosarcoma cisplatin resistance.

LGR5 acts as a target of miR-340-5p in the suppression of cell progression and drug resistance in breast cancer via Wnt/β-catenin pathway

Breast cancer is one of the most common malignant tumors among females. Recent studies demonstrated that microRNAs (miRNAs) played an important role in the regulation of tumor progression. In our present study, we firstly detected miR-340-5p expression in breast cancer cell lines and found lower expression of miR-340-5p in breast cancer cell lines (MCF-7, MDA-MB-231, BT-549, ZR-75-1) through qRT-PCR. Overexpressed miR-340-5p inhibited cell proliferation and drug resistance to docetaxel with enhanced cell apoptosis of breast cancer cells. Through bioinformatic prediction, we found that LGR5 was a potential target of miR-340-5p. LGR5 was highly expressed in breast cancer cells. Relative expression of LGR5 was negatively regulated by miR-340-5p. Knockdown of LGR5 also inhibited cell proliferation and drug resistance to docetaxel with enhanced cell apoptosis of breast cancer cells. Moreover, knockdown of LGR5 decreased the expression of β-catenin, c-myc, Survivin. The activation of Wnt/β-catenin pathway contracted the effects of LGR5 siRNA, indicating that LGR5 siRNA inhibited cell proliferation and drug resistance with induced apoptosis via suppressing Wnt/β-catenin signaling pathway in breast cancer. Taken together, our study demonstrated that overexpressed miR-340-5p inhibited cell proliferation and drug resistance with increased apoptosis of breast cancer cells through down-regulating LGR5 expression via Wnt/β-catenin pathway. The miR-340-5p/LGR5 axis may provide a new perspective for treatment for breast cancer.

Up-regulation of miR-340-5p promotes progression of thyroid cancer by inhibiting BMP4

PURPOSE

The incidence of thyroid cancer is increasing and the proliferation of thyroid cancer cells is incompletely understood. microRNAs may play key roles in thyroid cancer progression.

METHODS

We analyzed miR-340-5p in thyroid cancer tissue and normal tissue, and using informatics to predict its target. Cell lines and a mouse model were used to study the role of miR-340-5p in cancer proliferation.

RESULTS

Overexpression of miR-340-5p was found in thyroid cancer specimens. Tumors with higher pathological grade had higher levels of miR-340-5p. Overexpression of miR-340-5p significantly enhanced cell viability and colony formation. Treatment of anti-miR-340-5p, however, showed opposite alterations. We predicted that bone morphogenetic protein 4 (BMP4) is a possible target, and found a negative correlation between miR-340-5p and BMP4 levels in thyroid cancer tissue. miR-340-5p reduced BMP4 expression. BMP4 overexpression attenuated the effects of miR-340-5p in cell viability and colony formation. In addition, using a xenograft mouse model we proved that anti-miR-340-5p was able to inhibit tumor growth.

CONCLUSIONS

miR-340-5p promotes thyroid cancer proliferation by inhibiting BMP4. Anti-miR-340-5p can be a promising strategy to control thyroid cancer.

LncRNA CASC11 promoted gastric cancer cell proliferation, migration and invasion in vitro by regulating cell cycle pathway

In this study, we aimed to investigate the effects of lncRNA CASC11 on gastric cancer (GC) cell progression through regulating miR-340-5p and cell cycle pathway. Expressions of lncRNA CASC11 in gastric cancer tissues and cell lines were determined by qRT-PCR. Differentially expressed lncRNAs, mRNAs and miRNAs were screened through microarray analysis. The relationship among CASC11, CDK1 and miR-340-5p was predicted by TargetScan and validated through dual luciferase reporter assay. Western blot assay examined the protein level of CDK1 and several cell cycle regulatory proteins. GO functional analysis and KEGG pathway analysis were used to predict the association between functions and related pathways. Cell proliferation was determined by CCK-8 assays. Cell apoptosis and cell cycle were detected by flow cytometry assay. CASC11 was highly expressed in GC tissues and cell lines. Knockdown of CASC11 inhibited GC cell proliferation, promoted cell apoptosis and blocked cell cycle. KEGG further indicated an enriched cell cycle pathway involving CDK1. QRT-PCR showed that miR-340-5p was down-regulated in GC cells tissues, while CDK1 was up-regulated. Furthermore, CASC11 acted as a sponge of miR-340-5p which directly targeted CDK1. Meanwhile, miR-340-5p overexpression promoted GC cell apoptosis and induced cell cycle arrest, while CDK1 overexpression inhibited cell apoptosis and accelerated cell cycle. Our study revealed the mechanism of CASC11/miR-340-5p/CDK1 network in GC cell line, and suggested that CASC11 was a novel facilitator that exerted a biological effect by activating the cell cycle signaling pathway. This finding provides a potential therapeutic target for GC.

Up-regulation of microRNA-340 promotes osteosarcoma cell apoptosis while suppressing proliferation, migration, and invasion by inactivating the CTNNB1-mediated Notch signaling pathway

Osteosarcoma (OS) is the most common histological form of primary bone cancer. It is most prevalent in teenagers and young adults. The present study aims at exploring the regulatory effect of microRNA-340 (miR-340) on OS cell proliferation, invasion, migration, and apoptosis via regulating the Notch signaling pathway by targeting β-catenin (cadherin-associated protein) 1 (CTNNB1). OS tissues belonging to 45 patients and normal femoral head tissues of 45 amputees were selected. Cells were allocated to different groups. In situ hybridization was performed to determine the positive rate of miR-340 expression while immunohistochemistry was used to determine that of CTNNB1 and B-cell lymphoma 2 (Bcl-2). We used a series of experiments to measure the expressions of related factors and assess rates of cell proliferation, migration, invasion, cycle, and apoptosis respectively. Our results show that miR-340 was expressed a higher level in normal tissue than OS tissue. Expression of Notch, CTNNB1, hairy and enhancer of split 1 (Hes1), Bcl-2, Runt-related transcription factor 2 (Runx2), and osteocalcin increased and that of miR-340, Bcl-2 interacting mediator of cell death (BIM), and Bcl-2 associated protein X (Bax) decreased in OS tissues. U-2OS cell line had the highest miR-340 expression. We also found that the up-regulation of miR-340 had increased expression of miR-340, BIM, and Bax but decreased expression of Notch, CTNNB1, Hes1, Bcl-2, Runx2, and osteocalcin. Up-regulation of miR-340p lead to increased cell apoptosis, suppressed cell proliferation, migration, and invasion. Our study demonstrates that overexpression of miR-340 could suppress OS cell proliferation, migration, and invasion as well as promoting OS cell apoptosis by inactivating the Notch signaling pathway via down-regulating CTNNB1. Functional miR-340 overexpression might be a future therapeutic strategy for OS.

Expression of AGPAT2, an enzyme involved in the glycerophospholipid/triacylglycerol biosynthesis pathway, is directly regulated by HIF-1 and promotes survival and etoposide resistance of cancer cells under hypoxia

Hypoxia inducible factor-1 (HIF-1) supports survival of normal cells under low oxygen concentration and cancer cells in the hypoxic tumor microenvironment. This involves metabolic reprogramming via upregulation of glycolysis, downregulation of oxidative phosphorylation and, less well documented, effects on lipid metabolism. To investigate the latter, we examined expression of relevant enzymes in cancer cells grown under hypoxia. We show that expression of acylglycerol-3-phosphate acyltransferase 2 (AGPAT2), also known as lysophosphatidic acid acyltransferase β (LPAATβ), was upregulated under hypoxia and this was impaired by siRNA-mediated knockdown of HIF-1α. Moreover, a sequence of the AGPAT2 gene promoter region, containing 6 putative Hypoxia Response Elements (HREs), activated transcription of a reporter gene under hypoxic conditions or in normoxic cells over-expressing HIF-1α. Chromatin immunoprecipitation experiments confirmed binding of HIF-1α to one of these HREs, mutation of which abolished hypoxic activation of the AGPAT2 promoter. Knockdown of AGPAT2 by siRNA reduced lipid droplet accumulation and cell viability under hypoxia and increased cancer cell sensitivity to the chemotherapeutic etoposide. In conclusion, our findings demonstrate that AGPAT2, which is mutated in patients with congenital generalized lipodystrophy and over-expressed in different types of cancer, is a direct transcriptional target of HIF-1, suggesting that upregulation of lipid storage by HIF-1 plays an important role in adaptation and survival of cancer cells under low oxygen conditions.

MicroRNAs miR-19, miR-340, miR-374 and miR-542 regulate MID1 protein expression

The MID1 ubiquitin ligase activates mTOR signaling and regulates mRNA translation. Misregulation of MID1 expression is associated with various diseases including midline malformation syndromes, cancer and neurodegenerative diseases. While this indicates that MID1 expression must be tightly regulated to prevent disease states specific mechanisms involved have not been identified. We examined miRNAs to determine mechanisms that regulate MID1 expression. MicroRNAs (miRNA) are small non-coding RNAs that recognize specific sequences in their target mRNAs. Upon binding, miRNAs typically downregulate expression of these targets. Here, we identified four miRNAs, miR-19, miR-340, miR-374 and miR-542 that bind to the 3'-UTR of the MID1 mRNA. These miRNAs not only regulate MID1 expression but also mTOR signaling and translation of disease associated mRNAs and could therefore serve as potential drugs for future therapy development.

Effect of microRNA-128 on cisplatin resistance of glioma SHG-44 cells by targeting JAG1

This current study intends to investigate the effect of microRNA-128 (miR-128) on cisplatin (DDP) resistance in glioma SHG-44 cells. SHG-44/DDP cells were transfected with miR-128 antisense oligonucleotide (ASO) and assigned into blank, resistance, NC, anti-miR-128, miR-128 mimic, si-JAG1, and anti-miR-128 + si-JAG1 groups. qRT-PCR and Western blotting were employed for determining expression of miR-128, JAG1, Bax and Bcl-2. MTT assay, Giemsa staining, and flow cytometry were applied to detect DDP resistance, cellular morphology, and cell cycle, respectively. JAG1 is targeted and negatively regulated by miR-128. In in vitro experiments, compared with the blank group, the rest groups exhibited declined miR-28 and Bax expression, lowered cell inhibition rate and apoptosis rate, but elevated JAG1 and Bcl-2 expression with cells arrested in the S phase. Compared with the resistance group, the anti-miR-128 group showed decreasedBax expression along with a lowered cell inhibition rate and apoptosis rate, but increased JAG1 and Bcl-2 expression with reduced cells arrested in the S phase; while the miR-128 mimic group showed an opposite trend; the si-JAG1 group showed decreased Bcl-2 expression and reduced cells in the S phase. In in vivo experiments, compared with the resistance group, the tumor growth rate, tumor volume, and weight as well as JAG1 expression accelerated in the anti-miR-128 group; whereas the miR-128 mimic and si-JAG1 groups exhibited an opposite trend. Our findings demonstrated that miR-128 ASO transfection might down-regulate the expression of miR-128 in SHG-44/DDP and up-regulate the DDP resistance in SHG-44/DDP cells, providing a potential treatment target for glioma.