Search

MicroRNAs (miRNAs) are responsible for post-transcriptional gene regulation, and may function as valuable biomarkers for diseases diagnosis. Accurate and sensitive analysis of miRNAs is in great demand. Quantum dots (QDs) are semiconductor nanomaterials with superior optoelectronic features, such as high quantum yield and brightness, broad absorption and narrow emission, long fluorescence lifetime, and good photostability. Herein, we give a comprehensive review about QD-based biosensors for miRNA assay. Different QD-based biosensors for miRNA assay are classified by the signal types including fluorescent, electrochemical, electrochemiluminescent, and photoelectrochemical outputs. We highlight the features, principles, and performances of the emerging miRNA biosensors, and emphasize the challenges and perspectives in this field., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Hepatic ischemia-reperfusion injury (HIRI) is the major complication of liver surgery and liver transplantation, that may increase the postoperative morbidity, mortality, tumor progression, and metastasis. The underlying mechanisms have been extensively investigated in recent years. Among these, oxidative stress, inflammatory responses, immunoreactions, and cell death are the most studied. Non-coding RNAs (ncRNAs) are defined as the RNAs that do not encode proteins, but can regulate gene expressions. In recent years, ncRNAs have emerged as research hotspots for various diseases. During the progression of HIRI, ncRNAs are differentially expressed, while these dysregulations of ncRNAs, in turn, have been verified to be related to the above pathological processes involved in HIRI. ncRNAs mainly contain microRNAs, long ncRNAs, and circular RNAs, some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity, and as therapeutic targets to attenuate HIRI. Here, we briefly summarize the common pathophysiology of HIRI, describe the current knowledge of ncRNAs involved in HIRI in animal and human studies, and discuss the potential of ncRNA-targeted therapeutic strategies. Given the scarcity of clinical trials, there is still a long way to go from pre-clinical to clinical application, and further studies are needed to uncover their potential as therapeutic targets., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

DNA nanomachines have shown potential application in the construction of various biosensors. Here, an electrochemiluminescence biosensor for the sensitive detection of miRNA-21 were reported based on three-dimensional (3D) DNA nanomachine and duplex-specific nuclease (DSN)-mediated target recycle amplification strategy. First, the bipedal DNA walkers were obtained by DSN-mediated digestion reaction initiated by target miRNA-21.3D DNA tracks were prepared by modifying Fe 3 O 4 magnetic beads (MBs) with ferrocene-labeled DNA (Fc-DNA). The produced DNA walkers autonomously moved along 3D DNA tracks powered by nicking endonuclease. During the movement, ferrocene-labeled DNA was cleaved, resulting in large amounts of Fc-labeled DNA fragments away from the MBs surface. Finally, the liberated Fc-labeled DNA fragments were dropped on the C-g-C 3 N 4 modified electrode surface, leading to the quenching of C-g-C 3 N 4 electrochemiluminescence (ECL). Benefiting from the dual amplification strategy of 3D DNA nanomachine and DSN-mediated target recycling, the developed ECL biosensor exhibited an excellent performance for miRNA-21 detection with a wide linear range of 10 fM to 10 nM and a low detection limit of 1.0 fM. This work offers a new thought for the application of DNA walkers in the construction of various biosensors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

MicroRNA (miRNA)-related single-nucleotide polymorphisms (miR-SNPs) are a novel class of genetic variations involved in multiple cellular functions, and they have emerged as promising biomarkers for cancer diagnostics and prognostics. Herein, we demonstrate for the first time the structure-switchable hairpin-powered exponential replications for sensing attomolar miR-SNPs in human cancer tissues with zero background. In the presence of target miR-196a2T, hairpin probes (i.e., HP1 and HP2) are splinted together to construct the dumbbell-shaped probe (DSP) with SplintR ligase catalysis. Once the DSP is formed, the self-primed polymerization extension and linear FIP/BIP-primed strand displacement DNA synthesis (SDS) are automatically repeated to activate self-circulated exponential amplification, producing large amounts of double-stranded DNAs (dsDNAs) which can be real-time monitored using SYBR Green I. This nanodevice can detect miR-196a2T with an ultralow detection limit of 2.46 aM; distinguish rare miR-196a2 SNP with a selectivity factor of 0.001%; and even profile miR-196a2T in human tissues for nonsmall cell lung cancer (NSCLC) diagnosis, risk assessment, and cancer type prediction. Notably, this nanodevice can be rapidly and homogeneously used in one tube in a real-time and label-free manner, providing a powerful point-of-care platform for noninvasive diagnostics and prognostics of miR-SNPs-related human cancers.

Introduction: Dysregulation of spinal cord development can lead to serious neuronal damage and dysfunction, causing significant health problems in newborns. MiRNA-138 appears to be crucial for proliferation, differentiation, and apoptosis of cells. However, the regulation of miRNA-138 and downstream molecules in embryonic spinal cord development remain elusive. The aim of this experiment is to determine whether overexpression of miRNA-138 or RNA interference (RNAi) can regulate the development of spinal cord in fetal rats., Methods: Two plasmid vectors including pLenti-III-mico-GFP (miRNA-138 open reading frame [ORF]) and pLenti-III-miR-Off (miRNA-138 short hairpin) were constructed and injected into the tail vein of rats on the 14th day of pregnancy. Hematoxylin-eosin (HE) staining was used to observe the cell morphology. QRT-PCR, Western blot, and immunostaining confirmed the regulatory relationship between miRNA-138 and downstream molecules sonic hedgehog (Shh)., Results: Overexpression of miRNA-138 increased neuron regeneration significantly and decreased neuronal apoptosis when compared with the control. Silencing of miRNA-138 increased neuronal apoptosis and spinal cord atrophy significantly. Furthermore, miRNA-138 ORF treatment effectively increased the expression level of miRNA-138 and also upregulated the level of Shh. Comparatively, knockdown of miRNA-138 downregulated Shh levels in myelodysplastic regions., Conclusion: These findings indicated that miRNA-138 overexpression could protect the spinal cord development of fetal rats, and the underlying mechanisms were associated with Shh expression. The present study provides a novel strategy to promote the molecular mechanism of embryonic spinal cord development., (© 2022 The Author(s). Published by S. Karger AG, Basel.)

The aim of this study was to reveal the effect of let-7b on osteoporosis (OP). Synthetic let-7b mimics or inhibitors were transfected into MC3T3-E1 cells. The expression of let-7b in MC3T3-E1 and its effect on cell viability, apoptosis, and the apoptosis-related proteins (Bcl-2, Bax, and cleaved caspase-9) were tested by CCK-8 assay, flow cytometry and Western blot, severally. The osteogenic differentiation markers (Runx2 and Osterix) and Wnt/β-catenin pathway related markers (β-catenin and C-myc) were detected by qRT-PCR and Western blot. The relationships between let-7b and cyclin D1 (CCND1) were confirmed by luciferase reporter assay. The differentiation and mineralization of MC3T3-E1 cells were analyzed by alkaline phosphatase (ALP) activity assay and alizarin red staining. The outcomes indicated that overexpression/ablation of let-7b repressed/facilitated MC3T3-E1 cell viability and accelerated/suppressed MC3T3-E1 cell apoptosis. Besides, a remarkable decrease/augment of Bcl-2 protein expression and the distinct fortify/reduction of Bax and cleaved caspase-9 expression levels were observed in let-7b mimics/inhibitors group in MC3T3-E1 cells. Moreover, we discovered that let-7b overexpression/ablation retrained/facilitated the mRNA and protein expression of Runx2 and Osterix. It was confirmed that CCND1 was a downstream target of let-7b and was negatively modulated by let-7b. In addition, high-expression/deficiency of let-7b inhibited/increased the expression levels of β-catenin and C-myc in MC3T3-E1 cells. Taken together, our study revealed that let-7b overexpression/depletion repressed/accelerated MC3T3-E1 cell proliferation, differentiation, and mineralization while promoted/suppressed MC3T3-E1 cell apoptosis through targeting CCND1, which might be adjusted by Wnt/β-catenin pathway. Our findings might offer a basis for developing novel targets for OP treatment., (© 2020 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia on behalf of Kaohsiung Medical University.)

Circulating miRNAs are a newly emerging class of noninvasive biomarkers, and the accurate quantification of their expression is essential to the biological research and early clinic diagnosis. Herein, we demonstrate the construction of a quencher-free cascade amplification system for highly sensitive detection of serum circulating miRNAs. The target miRNA can hybridize with the linear probe to induce the cyclic strand displacement amplification (SDA) (cycle I) for the production of the binding probes. The binding probe can subsequently react with the 2-aminopurine (2-AP)-hairpin probe to induce the recycling exonuclease cleavage of 2-AP-hairpin probes (cycle II), releasing the triggers and 2-AP molecules simultaneously. The released trigger can hybridize with the free linear probe to start new cycles I and II amplifications. Through multiple rounds of cascade amplifications, a large number of 2-AP molecules are released, generating an enhanced fluorescence signal. This method exhibits a large dynamic range of 8 orders of magnitude and a detection limit of 0.16 aM. It can differentiate a single-base mismatch in miR-486-5p, quantify miR-486-5p in lung cancer cells at various stages, and even discriminate the expressions of serum circulating miR-486-5p in healthy persons from that in nonsmall-cell lung carcinoma (NSCLC) patients. Moreover, this assay can be rapidly carried out in one step under isothermal condition in a label-free manner, holding promising applications in point-of-care diagnosis and prognosis of lung cancers.

Background: MicroRNA-1258 (miR-1258) has been shown to play an anti-cancer role in a variety of cancers, but its relationship with papillary thyroid cancer (PTC) has not been reported. The emphasis of this research was to reveal the biological function of miR-1258 in PTC and its potential mechanisms., Material and Methods: We measured miR-1258 expression in PTC cells and the transfection efficiency of miR-1258 mimic and miR-1258 inhibitor by quantitative real-time PCR (qRT-PCR) assay. Cell Counting Kit-8 assay (CCK8) and Transwell experiments were conducted to examine the influences of altering miR-1258 expression on the viability, migration, and invasion of PTC cells. Bioinformatics prediction and dual-luciferase experiment were performed to verify the target gene of miR-1258. Finally, we carried out a rescue assay to verify whether the regulation of miR-1258 on the biological behaviour of PTC cells needs to be achieved by regulating TMPRSS4., Results: The outcomes revealed that miR-1258 was lowly expressed in PTC cell lines and miR-1258 showed the lowest expression in KTC-1 and the highest expression in B-CPAP among all tested PTC cell lines. Overexpression of miR-1258 inhibited KTC-1 cell viability and ability to migrate and invade, whereas inhibition of miR-1258 in B-CPAP cells has the opposite effect. Furthermore, we affirmed that miR-1258 can directly target TMPRSS4, and miR-1258 can reduce the biological malignant behaviour of PTC cells via regulation of TMPRSS4., Conclusion: Taken together, our research raised the possibility that miR-1258 was an anti-oncogene, which exerts its anti-cancer function by targeting TMPRSS4. Hence, it may be possible to treat PTC by targeting the miR-1258/TMPRSS4 axis in the future.

MicroRNAs (miRNAs or miRs) play an important role in pathological processes in diabetic nephropathy (DN). This study aimed to explore whether miR‑379‑5p is associated with renal fibrosis in DN and to elucidate the underlying mechanisms. In vitro experiments indicated that miR‑379‑5p expression was downregulated by high glucose (HG) treatment in mouse mesangial cells (MMCs). Transfection with miR‑379‑5p mimics suppressed the proliferation and the accumulation of extracellular matrix (ECM) components, which were promoted by HG treatment. LIN28B was proven to be a direct target of miR‑379‑5p by luciferase report assay. In addition, the loss of expression of LIN28B, as well as the decrease in cell proliferation and in the accumulation of ECM components, which were induced by the knockdown of LIN28B, were attenuated in the MMCs following transfection with miR‑379‑5p inhibitors. Furthermore, type 2 diabetic db/db mice were used to examine the efficiency of miR‑379‑5p agomir in the alleviation of renal fibrosis. Consistent with the results of the in vitro experiments, miR‑379‑5p agomir suppressed mesangial cell proliferation and the accumulation of ECM components by regulating the LIN28B/let‑7 pathway. Taken together, the findings of this study suggest that miR‑379‑5p is highly involved in renal fibrosis in DN, and that it may be a potential effective therapeutic target for DN.

BACKGROUND Worldwide, mortality from cervical cancer in women remains high. This study aimed to investigate the expression of long noncoding RNA (lncRNA) TP73-AS1, microRNA-329-3p (miRNA-329-3p), and the SMAD2 gene and their regulatory relationships in human cervical cancer tissue and cervical cancer cell lines. MATERIAL AND METHODS Cervical cancer tissue samples (n=30) and normal control cervical tissues were studied. Cell proliferation and migration were investigated in HeLa and SiHa human cervical cancer cells using the MTT assay, crystal violet staining, wound healing assay, and the transwell assay. Expression of lncRNA TP73-AS1 and the SMAD2 gene were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Enrichment of miR-329-3p was measured using the RNA immunoprecipitation assay (RIPA). Targeting relationships between TP73-AS1, miR-329-3p, and SMAD2 were identified using the dual-luciferase reporter assay. A subcutaneous xenograft model was established, tumor size was measured, and SMAD2 expression was detected using immunohistochemistry. RESULTS LncRNA TP73-AS1 was overexpressed in cervical cancer tissues and cells and was associated with reduced expression of miR-329-3p. Down-regulation of lncRNA TP73-AS1 inhibited cell proliferation, migration and invasion and increased miR-329-3p expression. Expression of SMAD2 down-regulated miR-329-3p and was associated with increased expression of TP73-AS1. LncRNA TP73-AS1 knockdown resulted in miR-329-3p silencing. In tumor xenografts, expression of TP73-AS1 reduced the tumor volume and down-regulated the expression levels of the SMAD2 gene. CONCLUSIONS LncRNA TP73-AS1 promoted proliferation of cervical cancer cell lines by targeting miR-329-3p to regulate the expression of the SMAD2 gene. A regulatory network was formed between lncRNA TP73-AS1, miR-329-3p, and SMAD2.

Long intergenic noncoding RNA 00961 (Linc00961) has been identified as a tumor suppressor in various types of cancer. However, the critical roles of Linc00961 in the carcinogenesis and progression of skin melanoma (SM) are yet to be fully elucidated. The present study revealed via reverse transcription‑quantitative PCR analysis that Linc00961 was downregulated in the tissues of patients with SM compared with benign nevi, and in A375, A2058 and SK‑MEL‑28 cell lines compared with human melanocytes. Furthermore, overexpression of Linc00961 inhibited cell proliferation, and promoted the apoptosis of A375 and SK‑MEL‑28 cells in vitro and in vivo, as determined by Cell Counting Kit‑8 and flow cytometry assays, and tumor xenograft studies, respectively. Overexpression of Linc00961 also led to an attenuation of the migration and invasive capabilities of A375 and SK‑MEL‑28 cells, measured using Transwell assays. Functionally, it was demonstrated that Linc00961 acted as a competing endogenous RNA (ceRNA) by competitively sponging microRNA‑367 (miR‑367) in A375 and SK‑MEL‑28 cells; restoration of miR‑367 rescued the inhibitory effects of Linc00961 on A375 and SK‑MEL‑28 cells. Finally, it was observed that phosphate and tension homology deleted on chromosome 10 (PTEN), an established target of miR‑367 in A375 and SK‑MEL‑28 cells, was positively regulated by Linc00961, and its inhibition reversed the inhibitory effects of Linc00961 on the proliferation and invasion of A375 and SK‑MEL‑28 cells. Collectively, the present study revealed that Linc00961 was downregulated in SM, and furthermore, Linc00961 was identified as a ceRNA that inhibits the proliferation and invasion of A375 and SK‑MEL‑28 cells by modulating the miR‑367/PTEN axis.

The specific functions and clinical significance of miR-940 in endometrial carcinoma (EC) have not been studied. First, we assessed the expression of miR-940 and MRVI1 in EC tissues collected from The Cancer Genome Atlas (TCGA) database and EC cell lines. miR-940 was significantly overexpressed in EC tissues and cell lines, particularly in RL95-2 cells. Correlation analysis showed that miR-940 expression level was remarkably associated with age, grade, and death. Moreover, the overall survival (OS) rate in the miR-940 low expression group was higher, compared with miR-940 high expression group. Univariate and multivariate models demonstrated that miR-940 expression, stage, and age were predictive indicators of OS. Moreover, there was no significance of the proliferation ability among the three EC cell lines (RL95-2, ISK, and KLE). To reveal the biological roles of miR-940, we respectively transfected RL95-2 cells with miR-940 mimics, miR-940 inhibitors, and control to further investigate the cell proliferation ability, and migration as well as invasion potential of RL95-2 cells. The transfection of miR-940 mimics significantly increased the proliferation and migration/invasion ability of RL95-2 cells. MRVI1 was predicted to be a potential target of miR-940 by means of in silico analysis followed by validation using luciferase reporter assays. MRVI1 was correlated with good prognosis. Moreover, forced expression of MRVI1 in miR-940 mimic transfected cells abolished the facilitation of miR-940 on cell proliferation, migration, and invasion of RL95-2 and KLE cells. In conclusion, our study demonstrates that miR-940 might function as a reliable diagnostic and prognostic signature in EC., (© 2019 The Author(s).)

Background: Numerous studies have evaluated the significance of the microRNA-10b (miR-10b) in the development and progression of many cancers. Their findings revealed that increased expression of miR-10b is associated with unfavorable prognosis in patients with cancer., Results: A total of 1,834 patients from 19 studies were included in this study. A significantly shorter overall survival was observed in patients with increased expression of miR-10b (hazard ratio [HR] = 1.99, 95% confidence interval [CI]: 1.51-2.61). Statistical significance was also observed in subgroup meta-analysis stratified by the cancer type, cutoff value, analysis type, and sample size. Also, patients with a high expression level of miR-10b had a poorer disease-free survival rate (HR = 1.18, 95% CI: 1.05-1.33). In addition, the pooled odds ratios (ORs) showed that increased miR-10b was also associated with positive lymph node metastasis (OR = 2.09, 95% CI: 1.45-3.03), distant metastasis (OR = 2.40, 95% CI: 1.57-3.67), tumor size (OR = 3.86, 95% CI: 2.25-6.64), and poor clinical stage (OR = 5.02, 95% CI: 3.37-7.47)., Materials and Methods: A systematic literature search was conducted on a number of electronic databases, including PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Springer, Google Scholar, and Gene expression omnibus. We retrieved the relevant articles to examine the association between the miR-10b expression levels and patients' prognosis. The meta-analysis was conducted using the RevMan 5.2 software and Stata SE12.0 software., Conclusions: High miR-10b expression was correlated with poor clinical outcome, which indicated the potential clinical use of miR-10b as a molecular biomarker for cancer, particularly in assessing prognosis for patients with cancers. Further studies should be performed to verify the clinical utility of miR-10b in human solid tumors., (© 2018 Wiley Periodicals, Inc.)

The critical long non‑coding RNAs (lncRNAs) involved in the carcinogenesis and progression of malignant melanoma (MM) have not been fully investigated. In the present study, it was identified that lncRNA activated by transforming growth factor‑β (lncRNA‑ATB) was upregulated in MM tissues and cells compared with benign nevus cells and human melanocytes, via comparative lncRNA screening from Gene Expression Omnibus datasets and reverse transcription‑quantitative polymerase chain reaction analysis. Furthermore, lncRNA‑ATB promoted the cell proliferation, cell migration, and cell invasion of MM cells in vitro, and tumor growth in vivo. It was additionally identified that lncRNA‑ATB attenuated cell cycle arrest and inhibited cellular apoptosis in MM cells. Finally, it was demonstrated that lncRNA‑ATB functions as a competing endogenous RNA (ceRNA) to enhance Yes associated protein 1 expression by competitively sponging microRNA miR‑590‑5p in MM cells. In conclusion, the present study revealed the expression and roles of lncRNA‑ATB in MM, and indicated that lncRNA‑ATB functions as a ceRNA to promote MM proliferation and invasion by sponging miR‑590‑5p.

It was found that the expression level of miR-147a was significantly increased and the pathway of PI3K/AKT was dramatically inhibited after radiation. In view of the relationship between miRNA and target genes, we put forward the question, what is the relationship between PI3K/AKT and miR-147a? In order to find the answer to the question, we used bioinformatics techniques to analyze the relationship between miR-147 (a or b) and PI3K/AKT signaling pathway. miR-147a overexpression plasmid and PDPK1 3'UTR luciferase reporter gene plasmid were constructed. Dual luciferase reporter gene system validation experiments were carried out on miR-147a and PDPK1 relationship. The verification experiments were also carried out. Bioinformatics analysis showed that there is a miR-147a binding site in the non-coding region (3'UTR) of PDPK1. In the experimental groups transfected with wild type PDPK1 gene of 3'UTR plasmid, the luciferase activity decreased (or increased) significantly in miR-147a (or inhibitor) group compared with miR-NC (or anti-miR-NC); There was no significant difference between the miR-147a group (or inhibitor) and the miR-NC group (or anti-miR-NC) in the transfection of PDPK1-3'UTR-Mut gene vector. PDPK1 was a target gene for direct regulation of miR-147a downstream. Verifying test results showed that the expression of PDPK1 mRNA and protein was reduced after overexpression of miR-147a, which was up-regulated after silencing miR-147a in TC, and V79 cells. These results suggest that miR-147a could be involved in the regulation of PDPK1 transcription by binding to the target site in PDPK1 mRNA 3'UTR, and then regulated AKT., (© 2017 Wiley Periodicals, Inc.)

In order to determine the diagnostic and prognostic value of miR-26a in Cholangiocarcinoma (CCA), we compared miR-26a levels in serum from 66 CCA patients and 66 healthy controls, which was followed by serum analysis between the pre-operative serum and post-operative serum of these CCA patients. We found the concentration levels of miR-26a in serum of CCA patients were significantly higher than that from healthy controls (P < 0.01). Furthermore, the concentration levels of miR-26a in the post-operative serum were significantly reduced when compared to the pre-operative serum (P < 0.001). High miR-26a in serum was correlated significantly with clinical stage, distant metastasis, differentiation status, and poor survival of CCA patients. More importantly, serum miR-26a was an independent prognostic marker for CCA. In conclusion, our results suggested that miR-26a in serum might be a potential and useful noninvasive biomarker for the early detection of CCA.

Accumulating evidence has demonstrated that microRNAs (miRNAs) are involved in multiple processes in cancer development and progression. miR-326 has been identified as a tumor suppressor miRNA in several types of human cancer. However, the specific function of miR-326 and its target the nin one binding protein (NOB1) in colorectal carcinoma (CRC) remains unclear. In the present study, we found that miR-326 inhibited cell proliferation, migration and invasion, and induced cell apoptosis and cell cycle arrest of CRC cells by directly targeting NOB1. Furthermore, the upregulation of miR-326 in CRC cells was revealed to be associated with a feedback loop involving downregulation of the NOB1, which mimics the phenotype induced by miR-326. Importantly, we found that the CRC patients with high expression of miR-326 or low expression of NOB1 tend to obtain a better prognosis. Thus, for the first time, we provide convincing evidence that downregulation of miR-326 inhibited tumor proliferation and tumor metastasis by directly targeting NOB1 in CRC. NOB1 and miR-326 could be potential therapeutic targets for CRC.

Intrahepatic cholangiocarcinoma (ICC) constitutes the second-most common primary hepatic malignancy. MicroRNAs (miRNAs) play important roles in the pathogenesis of ICC. However, the clinical significance of miR-21 levels in ICC remains unclear. Here, we investigated the role of miR-21 in ICC and found that its expression was significantly upregulated in serum of ICC patients. Serum miR-21 levels robustly distinguished ICC patients from control subjects. Further experiments showed that inhibition of miR-21 suppressed ICC cell proliferation in vitro and tumor growth in vivo. Specifically, inhibition of miR-21 induced cell cycle arrest and apoptosis. Moreover, PTPN14 and PTEN were identified as direct and functional targets of miR-21. Finally, we showed high expression levels of miR-21 were closely related to adverse clinical features, diminished survival, and poor prognosis in ICC patients. This study revealed functional and mechanistic links between miR-21 and tumor suppressor genes, PTPN14 and PTEN, in the pathogenesis of ICC. MiR-21 not only plays important roles in the regulation of cell proliferation and tumor growth in ICC, but is also a diagnostic and prognostic marker, and a potential therapeutic target for ICC.