miR-144-5p and miR-451a Inhibit the Growth of Cholangiocarcinoma Cells Through Decreasing the Expression of ST8SIA4

Targeted gene therapy for cancer: the impact of microRNA multipotentiality

Cancer is a life-threatening disease and its management is difficult due to its complex nature. Cancer is characterized by genomic instability and tumor-associated inflammation of the supporting stoma. With the advances in omics science, a treatment strategy for cancer has emerged, which is based on targeting cancer-driving molecules, known as targeted therapy. Gene therapy, a form of targeted therapy, is the introduction of nucleic acids into living cells to replace a defective gene, promote or repress gene expression to treat a disease. MicroRNAs (miRNAs) are non-coding RNAs (ncRNAs) that regulate gene expression and thus are involved in physiological processes like cell proliferation, differentiation, and cell death. miRNAs control the actions of many genes. They are deregulated in cancer and their abnormal expression influences genetic and epigenetic alterations inducing carcinogenesis. In this review, we will explain the role of miRNAs in normal and abnormal gene expression and their usefulness in monitoring cancer patients. Besides, we will discuss miRNA-based therapy as a method of gene therapy and its impact on the success of cancer management.

The interplay of signaling pathways with miRNAs in cholangiocarcinoma pathogenicity and targeted therapy

Cholangiocarcinoma (CCA), the second most frequent liver cancer after hepatocellular carcinoma, has been rising worldwide in recent epidemiological research. This neoplasia's pathogenesis is poorly understood. Yet, recent advances have illuminated the molecular processes of cholangiocyte malignancy and growth. Late diagnosis, ineffective therapy, and resistance to standard treatments contribute to this malignancy's poor prognosis. So, to develop efficient preventative and therapy methods, the molecular pathways that cause this cancer must be better understood. MicroRNAs (miRNAs) are non-coding ribonucleic acids (ncRNAs) that influence gene expression. Biliary carcinogenesis involves abnormally expressed miRNAs that act as oncogenes or tumor suppressors (TSs). The miRNAs regulate multiple gene networks and are involved in cancer hallmarks like reprogramming of cellular metabolism, sustained proliferative signaling, evasion of growth suppressors, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, and avoidance of immune destruction. In addition, numerous ongoing clinical trials are demonstrating the efficacy of therapeutic strategies based on miRNAs as powerful anticancer agents. Here, we will update the research on CCA-related miRNAs and explain their regulation involved in the molecular pathophysiology of this malignancy. Eventually, we will disclose their potential as clinical biomarkers and therapeutic tools in CCA.

MiR-144/451a cluster synergistically modulates growth and metastasis of Oral Carcinoma

OBJECTIVES

MicroRNA (miRNA) clusters co-transcribe and function in a coordinated fashion mediating synergistic or antagonistic regulatory effects. MiR-144 and miR-451a are deregulated in various cancers but the combined regulatory role of miR-144/451a cluster in oral squamous cell carcinoma (OSCC) remains unexplored. In the present study, we studied the synergistic effect of miR-144/451a cluster on oral cancer progression.

MATERIALS AND METHODS

miR-144 and miR-451a expression was explored in OSCC cell lines by quantitative real-time PCR (qRT-PCR). Proliferation, wound healing, migration and invasion, spheroid formation, and colony formation assays were performed after transfection with miR-144-3p, miR-451a, miR-144-5p, and co-expressed miR-144/451a. Expression of putative target genes was analyzed using qRT-PCR and Western blotting.

RESULTS

miR-144 and miR-451a were downregulated in all cell lines. The cell viability and stemness of cancer cell lines were unaltered when treated with miRNA mimics. However, co-expressed miR-144/451a significantly reduced the migratory, invasive, and clonogenic potential of cells than individual miRNAs.

CONCLUSION

miR-144/451a cluster functions as a tumor suppressor in OSCC by inhibiting cancer cell invasion, migration, and clonogenic potential.

A review on the role of ncRNAs in the pathogenesis of cholangiocarcinoma

Cholangiocarcinoma is a rare tumor but a challenging cancer in terms of pathological changes, clinical manifestations and therapeutic options. Recent studies have provided evidence for participation of non-coding RNAs in the carcinogenic process of cholangiocarcinoma. We demonstrate the role of long non-coding RNAs, microRNAs and circular RNAs in the pathogenesis of cholangiocarcinoma and highlight their significant position as therapeutic targets and biomarkers for this type of cancer. We also list a number of molecular axes comprising these non-coding RNAs that represent potential targets for therapeutic options in cholangiocarcinoma, based on their significant roles in the regulation of cell proliferation, differentiation and apoptosis of these cells.

miR-29c Suppresses the Malignant Phenotype of Hepatocellular Carcinoma Cells In Vitro by Mediating TPX2 Associated with Immune Infiltration

BACKGROUND

miR-29-3p, an important tumor suppressor, with inhibitory effects in multiple cancers that have been studied. Its exact molecular function is in HCC, however, still not been explored clearly. The purpose of our study is to make certain how miR-29c-3p affects HCC through TPX2.

MATERIALS AND METHODS

Expression profile data of miR-29c-3p and TPX2 were acquired and downloaded from the TCGA database, and the respective differential expression was verified by qPCR and immunohistochemistry. The StarBase and dual luciferase reporter confirmed TPX2 targeting miR-29c-3p. Their effects on the biological functions of Hep3B and HepG2 were investigated by cellular assays.

RESULTS

miR-29-3p was found to be significantly down-regulated in HCC, and the miR-29-3p low expression group had a poor prognosis. Overexpression of miR-29-3p was detrimental to invasion and migration ability of HCC cells and promoted their apoptosis. We identified miR-29c-3p targeting TPX2 by predictive analysis. TPX2 was significantly upregulated in HCC, and patients with high TPX2 expression had a poor prognosis. TPX2 knockdown partially counteracted the promoting effect of miR-29-3p inhibition on hepatocellular carcinoma cells, and its effect on hepatocellular carcinoma cell biology was similar to miR-29c-3p overexpression.

CONCLUSION

miR-29c, a key gene regulating HCC, is lowly expressed in HCC, its overexpression can remarkably inhibit the biological function of tumor cells. miR-29c can perform this function by regulating the expression of TPX2.

The Mutual Relationship between Glycosylation and Non-Coding RNAs in Cancer and Other Physio-Pathological Conditions

Glycosylation, which consists of the enzymatic addition of sugars to proteins and lipids, is one of the most important post-co-synthetic modifications of these molecules, profoundly affecting their activity. Although the presence of carbohydrate chains is crucial for fine-tuning the interactions between cells and molecules, glycosylation is an intrinsically stochastic process regulated by the relative abundance of biosynthetic (glycosyltransferases) and catabolic (glycosidases) enzymes, as well as sugar carriers and other molecules. Non-coding RNAs, which include microRNAs, long non-coding RNAs and circRNAs, establish a complex network of reciprocally interacting molecules whose final goal is the regulation of mRNA expression. Likewise, these interactions are stochastically regulated by ncRNA abundance. Thus, while protein sequence is deterministically dictated by the DNA/RNA/protein axis, protein abundance and activity are regulated by two stochastic processes acting, respectively, before and after the biosynthesis of the protein axis. Consequently, the worlds of glycosylation and ncRNA are closely interconnected and mutually interacting. In this paper, we will extensively review the many faces of the ncRNA-glycosylation interplay in cancer and other physio-pathological conditions.

Identification of Novel m6A-Related Long Non-Coding RNA Signatures for Cholangiocarcinoma Using Integrated Bioinformatics Analyses

Traditional methods used to treat cholangiocarcinoma are less effective, and the identification of new CHOL signature genes can help in the early clinical diagnosis and intervention of cholangiocarcinoma. In this work, we used integrated bioinformatics analysis to find new m6a-associated lncRNA signatures in cholangiocarcinoma. Pearson correlation test was used to identify m6A-lncRNAs by co-expression analysis of m6A-mrna and lncRNAs. we then selected m6A-lncRNAs co-expressed with METTL3 and METTL14 genes and screened for DEm6A-lncRNAs by comparing expression differences. we then used R package of Spearman coefficient correlation analysis to investigate the relevance of m6A-lncrna expression in CHOL. To determine the relative levels of immune cell infiltration, we performed ssGSEA analysis on all samples using the R package, and then we used graphs to illustrate the differences in immune cell infiltration between the CHOL and NC groups. The results of this study will help to identify new CHOL-causing biosignatures, which are important for the early clinical detection and management of CHOL.

Berberine Promotes A549 Cell Apoptosis and Autophagy via miR-144

Objective: To explore the effects of berberine on A549 lung cancer cells and corresponding changes in miR-144 expression, and the apoptosis and autophagy pathways. Methods: Cell proliferation was detected by cell counting Kit-8. The expression of miR-144 by quantitative PCR, caspase-3, caspase-3 cleaved, Bcl-2, Bax, beclin-1, LC3I, and LC3II were assessed using Western blot. Results: A549 proliferation was reduced with increasing berberine concentration. Berberine appeared to suppress A549 proliferation through apoptosis and autophagy, and, additionally, enhanced miR-144 expression. Berberine promoted A549 cell apoptosis by inhibiting caspase-3 cleavage and Bcl-2 expression and promoting Bax expression. Berberine also promoted A549 autophagy by raising the expression of beclin-1, LC3I, and LC3II. Conclusions: Berberine promotes A549 apoptosis and autophagy via miR-144.

An area of greatest vulnerability - recent advances in kidney injury

In this issue of the Biomedical Journal the reader is provided with an insight into the latest observations and advances in acute kidney injury as well as chronic kidney disease. The current SARS-CoV-2 variants are reviewed, and the role of long non-coding RNA in HIV therapy is explored. Furthermore, the potential of metabolomics as means to diagnose multiple sclerosis as well as tuberculosis is presented. Other topics of this issue include the restoration of the spermatogonial stem cell niche; atherosclerosis and the use of improved ultrasound images; and the effect of transcranial magnetic stimulation in patients with autism spectrum disorder. Finally, it is shown how continuous passive motion can be used as supportive therapeutic approach in children with cerebral palsy, and minimally invasive surgery is presented as valid alternative in cases of spine metastasis.

miR-532-3p suppresses proliferation and invasion of ovarian cancer cells via GPNMB/HIF-1α/HK2 axis

OBJECTIVE

Identifying a new target of miR-532-3p and studying its functional mechanism to explore the detailed anti-tumor mechanism of miR-532-3p in ovarian cancer.

METHODS

Biological and molecular methods including real-time quantitative PCR (RT-qPCR), Western blotting, colony formation, in vitro migration and invasion assays, glucose consumption and lactate production assays, RNA interference and tumor xenograft mouse models were used to study the role of miR-532-3p and its target in ovarian cancer. mRNA sequencing, dual-luciferase reporter assay and immunohistochemistry (IHC) were used to identify miR-532-3p target. STRING dataset analysis, qPCR and Western blotting were used to investigate the downstream pathway of the target of miR-532-3p.

RESULTS

Forced expression of miR-532-3p inhibited the proliferation, migration and invasion of ovarian cancer cells in vitro and the tumor growth in nude mice. RNA sequencing found 299 mRNAs were downregulated in miR-532-3p-overexpressed ovarian cancer cells, and bioinformatic analysis indicated Glycoprotein Nonmetastatic Melanoma Protein B (GPNMB), a type I membrane glycoprotein, was the potential target of miR-532-3p. GPNMB was reduced at both RNA and protein levels in miR-532-3p-overexpressed ovarian cancer cells. Dual-luciferase reporter assay determined GPNMB as the target of miR-532-3p. Interference of GPNMB inhibited the proliferation, migration, invasion, glucose consumption and lactate production of ovarian cancer cells. Knocking down of GPNMB reduced the protein level of HIF-1α without affecting HIF-1α mRNA level. Overexpression of GPNMB reversed the antitumor effect of miR-532-3p.

CONCLUSION

miR-532-3p exerted the anti-cancer effect by targeting GPNMB/ HIF-1α/ HK2 pathway to inhibit aerobic glycolysis in ovarian cancer.

Analysis of miRNA Expression Profiling of RIP2 Knockdown in Chicken HD11 Cells When Infected with Avian Pathogenic E. coli (APEC)

Colibacillosis is an acute and chronic avian disease caused by avian pathogenic E. coli (APEC). Previous studies have demonstrated that RIP2 plays a significant role in APEC infection. Moreover, increasing evidence indicates that microRNAs (miRNAs) are involved in host–pathogen interactions and the immune response. However, the role of miRNAs in the host against APEC infection remains unclear. Herein, we attempted to reveal new miRNAs potentially involved in the regulation of the immune and inflammatory response against APEC infection, with a particular focus on those possibly correlated with RIP2 expression, via miRNA-seq, RT-qPCR, Western blotting, dual-luciferase reporter assay, and CCK-8. The results showed that a total of 93 and 148 differentially expressed (DE) miRNAs were identified in the knockdown of RIP2 cells following APEC infection (shRIP2+APEC) vs. knockdown of RIP2 cells (shRIP2) and shRIP2 vs. wild-type cells (WT), respectively. Among those identified DE miRNAs, the biological function of gga-miR-455-5p was investigated. It was found that gga-miR-455-5p regulated by RIP2 was involved in the immune and inflammatory response against APEC infection via targeting of IRF2 to modulate the expression of type I interferons. Additionally, RIP2 could directly regulate the production of the type I interferons. Altogether, these findings highlighted the crucial role of miRNAs, especially gga-miR-455-5p, in host defense against APEC infection.

Micro-RNA in Cholangiocarcinoma: Implications for Diagnosis, Prognosis, and Therapy

Bile-duct cancers (BDC) are a group of solid tumors arising from the biliary tree. Despite their classification as rare cancers, the incidence of BDC is increasing worldwide. Poor prognosis is a common feature of this type of cancer and is mainly determined by the following factors: late diagnosis, lack of effective therapeutic approaches, and resistance to conventional treatments. In the past few years, next-generation sequencing technologies has allowed us to study the genome, exome, and transcriptome of BDC deeper, revealing a previously underestimated class of RNA: the noncoding RNA (ncRNA). MicroRNAs (miRNAs) are small ncRNAs that play an important regulatory role in gene expression. The aberrant expression of miRNAs and their pivotal role as oncogenes or tumor suppressors in biliary carcinogenesis has been widely described in BDC. Due to their ability to regulate multiple gene networks, miRNAs are involved in all cancer hallmarks, including sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing/accessing vasculature, activating invasion and metastasis, reprogramming cellular metabolism, and avoiding immune destruction. Their use as diagnostic, prognostic, and predictive biomarkers has been widely explored in several human cancers, including BDC. Furthermore, miRNA-based therapeutic strategies are currently the subject of numerous clinical trials that are providing evidence of their efficacy as potent anticancer agents. In this review, we will provide a detailed update of miRNAs affecting BDC, discussing their regulatory function in processes underlying the molecular pathology of BDC. Finally, an overview of their potential use as biomarkers or therapeutic tools in BDC will be further addressed.

Dysregulation of miR-144-5p/RNF187 axis contributes to the progression of colorectal cancer

Background and Objectives

RING finger protein 187 (RNF187) belongs to RING domain-containing E3 ligases family, which was recently reported to be involved in oncogenesis and development of several cancers. This research aims to clarify the role of RNF187 in colorectal cancer (CRC) development.

Methods

The expression of RNF187 and miR-144-4p were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of RNF187 protein were assessed by western blot analysis. Cell Counting Kit-8 (CCK8) assay, clonogenic assay, cell scratch test and transwell assay were used to determine the proliferation, migration and invasion of CRC cells in vitro. The binding of miR-144-5p and RNF197 mRNA was validated by luciferase reporter assays. Tumor-bearing nude mice were used to determine CRC cells growth in vivo.

Results

RNF187 expression significantly increased in CRC specimens and cell lines compared to normal colon tissues and normal colonic mucosa cell line, respectively. Upregulation of RNF187 expression was inversely correlated to poor prognosis in CRC patients. In addition, knockdown of RNF187 expression inhibited the proliferation, migration, and invasion but promoted the apoptosis of CRC lines Caco-2 and SW480 cells. Further studies validated that RNF187 was the direct target of miR-144-5p. The expression of miR-144-5p was downregulated in CRC tissues, which was negatively correlated to the expression of RNF187. Restoration of miR-144-5p significantly inhibited the progression of CRC cells and its anti-tumor effects could be abrogated by overexpression of RNF187.

Conclusion

Our findings demonstrate the deregulation of miR-144-5p/ RNF187 axis in CRC, as well as its role in regulation of the tumor progression, thus providing a novel therapeutic strategy for CRC treatment.

LncRNA LINC00461 exacerbates myocardial ischemia-reperfusion injury via microRNA-185-3p/Myd88

OBJECTIVE

Long non-coding RNAs (lncRNAs) play critically in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury. Thus, it was proposed to investigate the mechanism of LINC00461 in the disease through mediating microRNA-185-3p (miR-185-3p)/myeloid differentiation primary response gene 88 (Myd88) axis.

METHODS

miR-185-3p, LINC00461 and Myd88 expression in mice with I/R injury was measured. Mice with I/R injury were injected with the gene expression-modified vectors, after which cardiac function, hemodynamics, myocardial enzyme, oxidative stress, and cardiomyocyte apoptosis were analyzed.

RESULTS

I/R mice showed LINC00461 and Myd88 up-regulation and miR-185-3p down-regulation. Down-regulating LINC00461 or up-regulating miR-185-3p recovered cardiac function, reduced myocardial enzyme levels, and attenuated oxidative stress and cardiomyocyte apoptosis in mice with I/R. miR-185-3p overexpression rescued the promoting effect of LINC00461 upregulation on myocardial injury in I/R mice.

CONCLUSION

LINC00461 knockdown attenuates myocardial I/R injury via elevating miR-185-3p expression to suppress Myd88 expression.

Cholangiopathies and the noncoding revolution

PURPOSE OF REVIEW

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) among others, have attracted a great deal of attention for their potential role as master regulators of gene expression and as therapeutic targets. This review focuses on recent advances on the role of ncRNAs in the pathogenesis, diagnosis and treatment of diseases of the cholangiocytes (i.e. cholangiopathies).

RECENT FINDINGS

In the recent years, there has been an exponential growth in the knowledge on ncRNAs and their role in cholangiopathies, particularly cholangiocarcinoma.

SUMMARY

Although several studies focused on miRNAs as noninvasive biomarkers for diagnosis and staging, several studies also highlighted their functions and provided new insights into disease mechanisms.

MiR-10b-3p alleviates cerebral ischemia/reperfusion injury by targeting Krüppel-like factor 5 (KLF5)

Although miR-10b-3p has been identified to be involved in cerebral ischemia injury, its impact and specific mechanism in cerebral ischemia injury remain unclear. The effects of Mir-10b-3p were investigated by establishing rat and cell models of ischemia/reperfusion (I/R) injury. Oxygen-glucose deprivation/reperfusion (OGD/R) was performed on pheochromocytoma-12 (PC12) cells. MiR-10b-3p expression levels in brain tissues and PC12 cells were detected by qRT-PCR. The impacts of miR-10b-3p on neurological deficits, infarct volume, inflammatory factor expression, in vivo brain water content, cell viability, and cell apoptosis were assessed. The relationship between miR-10b-3p and KLF5 was determined by TargetScan and luciferase reporter assay. The rescue experiments were performed to confirm the role of this axis in cerebral ischemia injury. Mir-10b-3p levels in rat brain tissue and PC12 cells were significantly decreased after I/R injury. MiR-10b-3p overexpression obviously reduced neurological deficits, infarct volume, brain water content, inflammatory factors expression, and neuronal apoptosis in the brain of ischemia-stroked rats. Meanwhile, miR-10b-3p upregulation also inhibited cell viability and apoptosis of OGD/R-induced PC12 cells. Besides, KLF5 was identified as a target of miR-10b-3p, and rescue experiments revealed that KLF5 was involved in the regulation of miR-10b-3p in ischemic injury. Our results demonstrated that miR-10b-3p had the neuroprotective effects against ischemia injury by targeting KLF5 and provided a potential underlying target for ischemic stroke treatment.

Inhibition of Long non-coding RNA zinc finger antisense 1 improves functional recovery and angiogenesis after focal cerebral ischemia via microRNA-144-5p/fibroblast growth factor 7 axis

Long non-coding RNA zinc finger antisense 1 (ZFAS1) has been probed in cerebral ischemia, while the regulatory mechanism of ZFAS1 in focal cerebral ischemia (FCI) via binding to microRNA (miR)-144-5p remains rarely explored. This study aims to decipher the function of ZFAS1 on FCI via sponging miR-144-5p to modulate fibroblast growth factor 7 (FGF7). The focal cerebral ischemia rat model was established by occlusion of the middle cerebral artery (MCAO) Lentivirus vectors altering ZFAS1, miR-144-5p or FGF7 expression were injected into rats before MCAO. Then, ZFAS1, miR-144-5p, and FGF7 levels were detected, the inflammatory factor level, oxidative stress level, angiogenesis, neurological function injury and neuronal apoptosis were assessed. The binding relations among ZFAS1, miR-144-5p and FGF7 were validated. ZFAS1 and FGF7 expression was elevated, while miR-144-5p expression was reduced in FCI rats. Decreased ZFAS1 or FGF7 or enriched miR-144-5p repressed the inflammatory response, oxidative stress, neuronal apoptosis, while it improved angiogenesis, and neurological function recovery; while up-regulated ZFAS1 exerted opposite effects. The augmented miR-144-5p or silenced FGF7 reversed the effects of enriched ZFAS1. ZFAS1 sponged miR-144-5p that targeted FGF7. Inhibition of lncRNA ZFAS1 improves functional recovery and angiogenesis after FCI via miR-144-5p/FGF7 axis. This study provides novel therapeutic targets for FCI treatment.

The Role of microRNAs in Cholangiocarcinoma

Cholangiocarcinoma (CCA), an aggressive malignancy, is typically diagnosed at an advanced stage. It is associated with dismal 5-year postoperative survival rates, generating an urgent need for prognostic and diagnostic biomarkers. MicroRNAs (miRNAs) are a class of non-coding RNAs that are associated with cancer regulation, including modulation of cell cycle progression, apoptosis, metastasis, angiogenesis, autophagy, therapy resistance, and epithelial–mesenchymal transition. Several miRNAs have been found to be dysregulated in CCA and are associated with CCA-related risk factors. Accumulating studies have indicated that the expression of altered miRNAs could act as oncogenic or suppressor miRNAs in the development and progression of CCA and contribute to clinical diagnosis and prognosis prediction as potential biomarkers. Furthermore, miRNAs and their target genes also contribute to targeted therapy development and aid in the determination of drug resistance mechanisms. This review aims to summarize the roles of miRNAs in the pathogenesis of CCA, their potential use as biomarkers of diagnosis and prognosis, and their utilization as novel therapeutic targets in CCA.

Current Advances in Basic and Translational Research of Cholangiocarcinoma

Simple Summary

Cholangiocarcinoma (CCA) is highly malignant biliary tract cancer, which is characterized by limited treatment options and poor prognosis. Basic science studies to seek therapies for CCA are also limited due to lack of gold-standard experimental models and heterogeneity of CCA resulting in various genetic alterations and origins of tumor cells. Recent studies have developed new experimental models and techniques that may facilitate CCA studies leading to the development of novel treatments. This review summarizes the update in current basic studies of CCA.

Abstract

Cholangiocarcinoma (CCA) is a type of biliary tract cancer emerging from the biliary tree. CCA is the second most common primary liver cancer after hepatocellular carcinoma and is highly aggressive resulting in poor prognosis and patient survival. Treatment options for CCA patients are limited since early diagnosis is challenging, and the efficacy of chemotherapy or radiotherapy is also limited because CCA is a heterogeneous malignancy. Basic research is important for CCA to establish novel diagnostic testing and more effective therapies. Previous studies have introduced new techniques and methodologies for animal models, in vitro models, and biomarkers. Recent experimental strategies include patient-derived xenograft, syngeneic mouse models, and CCA organoids to mimic heterogeneous CCA characteristics of each patient or three-dimensional cellular architecture in vitro. Recent studies have identified various novel CCA biomarkers, especially non-coding RNAs that were associated with poor prognosis or metastases in CCA patients. This review summarizes current advances and limitations in basic and translational studies of CCA.

miR-let-7c-5p and miR-149-5p inhibit proinflammatory cytokine production in osteoarthritis and rheumatoid arthritis synovial fibroblasts

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two of the most common types of arthritis. Both are characterized by the infiltration of a number of proinflammatory cytokines into the joint microenvironment. miRNAs play critical roles in the disease processes of arthritic disorders. However, little is known about the effects of miRNAs on critical inflammatory cytokine production with OA and RA progression. Here, we found higher levels of proinflammatory cytokines including interleukin 1 beta (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in human OA and RA synovial fibroblasts (SFs) compared with normal SFs. Searches of open-source microRNA (miRNA) software determined that miR-let-7c-5p and miR-149-5p interfere with IL-1β, IL-6 and TNF-α transcription; levels of all three proinflammatory cytokines were lower in human OA and RA patients compared with normal controls. Anti-inflammatory agents dexamethasone, celecoxib and indomethacin reduced proinflammatory cytokine production by promoting the expression of miR-let-7c-5p and miR-149-5p. Similarly, ibuprofen and methotrexate also enhanced miR-let-7c-5p and miR-149-5p expression in human SFs. The evidence suggests that increasing miR-let-7c-5p and miR-149-5p expression is a novel strategy for OA and RA.