miR-124 suppresses proliferation and invasion of nasopharyngeal carcinoma cells through the Wnt/β-catenin signaling pathway by targeting Capn4

Regulatory role of miRNAs in nasopharyngeal cancer involving PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F signaling pathways: A review

MicroRNAs (miRNA) are small and conserved noncoding RNA molecules that regulate gene expression at the posttranscriptional level. These groups of RNAs are crucial in various cellular processes, especially in mediating disease pathogenesis, particularly cancer. The dysregulation of miRNAs was reported in many cancer types, including nasopharyngeal cancer (NPC), which is a malignant tumor of the nasopharynx. In this review, miRNAs involvement in crucial signaling pathways associated with NPC such as PTEN/PI3K/AKT, TGFβ/SMAD, RAS/MAPK, Wnt/β-catenin and pRB-E2F was investigated. miRNAs could function as tumor suppressor-miR or onco-miR in NPC profoundly influenced cell cycle, apoptosis, proliferation, migration, and metastasis. This comprehensive review of current literature provided a thorough profile of miRNAs and their interplay with the aforementioned signaling pathways in NPC. Understanding these molecular interactions could remarkably impact the diagnosis, prognosis, and therapeutic strategies for NPC.

Precision medicine in nasopharyngeal carcinoma: comprehensive review of past, present, and future prospect

Nasopharyngeal carcinoma (NPC) is an aggressive malignancy with high propensity for lymphatic spread and distant metastasis. It is prominent as an endemic malignancy in Southern China and Southeast Asia regions. Studies on NPC pathogenesis mechanism in the past decades such as through Epstein Barr Virus (EBV) infection and oncogenic molecular aberrations have explored several potential targets for therapy and diagnosis. The EBV infection introduces oncoviral proteins that consequently hyperactivate many promitotic pathways and block cell-death inducers. EBV infection is so prevalent in NPC patients such that EBV serological tests were used to diagnose and screen NPC patients. On the other hand, as the downstream effectors of oncogenic mechanisms, the promitotic pathways can potentially be exploited therapeutically. With the apparent heterogeneity and distinct molecular aberrations of NPC tumor, the focus has turned into a more personalized treatment in NPC. Herein in this comprehensive review, we depict the current status of screening, diagnosis, treatment, and prevention in NPC. Subsequently, based on the limitations on those aspects, we look at their potential improvements in moving towards the path of precision medicine. The importance of recent advances on the key molecular aberration involved in pathogenesis of NPC for precision medicine progression has also been reported in the present review. Besides, the challenge and future outlook of NPC management will also be highlighted.

Chlorpyrifos triggers epithelioma papulosum cyprini cell pyroptosis via miR-124-3p/CAPN1 axis

Chlorpyrifos (CPF), a widely used organophosphorus pesticide has caused water pollution, threatening aquatic organisms. MicroRNAs (miRNAs) highly conserved noncoding RNAs, that regulate various cell death processes, including pyroptosis. To investigate the effect of CPF exposure on epithelioma papulosum cyprini (EPC) cell pyroptosis and the role of the miR-124-3p/CAPN1 axis, we established miR-124 overexpression and inhibition EPC cell models of CPF exposure. The target of the miR-124-3p/CAPN1 axis was primarily confirmed by the double luciferase reporter assay. Pyroptosis was demonstrated to occur in CPF-exposed EPC cells and was accompanied by mitochondrial membrane potential depletion, ROS level elevation and pyroptotic indicator expression upregulation. PD150606 was supplied as a CAPN1 inhibitor, alleviating CPF-induced mitochondrial dysfunction, and alleviating the increased expression of NLRP3, CASP1, IL1β and GSDMD. In conclusion, CPF induces pyroptosis by regulating the miR-124-3p/CAPN1 axis. This study enriches the cytotoxicity study of CPF, and provides new theoretical fundamentals for exploration of miRNA and its target protein response to water contaminants.

MicroRNA-124-3p inhibited progression of nasopharyngeal carcinoma by interaction with PCDH8 and the inactivation of PI3K/AKT/mTOR pathway

Nasopharyngeal carcinoma (NPC) is characterised by distinct geographical distribution and is particularly prevalent in Asian countries. But the mechanisms related to the progression of nasopharyngeal carcinoma (NPC) are not completely understood. MiR-124-3p functions as a tumor suppressor in many kinds of human cancers. Here, we explored the effects and mechanism of miR-124-3p on the proliferation and colony formation in NPC. In our study, we reported that miR-124-3p was significantly downregulated in NPC tissues and cell lines. Overexpression miR-124-3p decreased NPC cell proliferation and colony formation abilities. Meanwhile, knockdown miR-124-3p increased proliferation and colony formation abilities. Additionally, dual-luciferase assay showed that miR-124-3p could positively regulated PCDH8 by targeting its 3'-UTR. Overexpression of PCDH8 could partially rescue the proliferation and colony formation role of miR-124-3p inhibitor. Our study indicated that miR-124-3p played a tumor suppressor by directly interacting with PCDH8 and inhibiting the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway. Overall, we found that miR-124-3p inhibited the activation of the PI3K/AKT/mTOR signaling pathway in NPC by interacting with PCDH8. Thus, PCDH8 may be a potential molecular target that impeded NPC proliferation and colony formation.

MicroRNA-124-3p suppresses PD-L1 expression and inhibits tumorigenesis of colorectal cancer cells via modulating STAT3 signaling

Programmed death ligand 1 (PD-L1) plays a significant role in colorectal tumorigenesis through induction of regulatory T cells (Tregs) and suppression of antitumor immunity. Furthermore, microRNAs (miRNAs) as the posttranscriptional regulators of gene expression show considerable promise as a therapeutic target for colorectal cancer (CRC) treatment. Considering this, in vitro effects of miRNA-124 (miR-124-3p) on CRC cell tumorigenesis and Tregs differentiation via targeting PD-L1 were investigated in the current study. Functional analysis showed that miR-124 is significantly downregulated in CRC tissues as compared with marginal normal samples (p < .0001), and its downregulation was negatively correlated with PD-L1 expression. Moreover, a specific region in PD-L1 3'-untranslated region was predicted as the miR-124 target and validated using the luciferase assay. Further investigation showed that transfection of HT29 and SW480 cells with miR-124 mimics significantly reduced PD-L1 mRNA, protein, and cell surface expression, and inhibited Tregs in coculture models via modulating interleukin [IL]-10, IL-2, tumor necrosis factor α, transforming growth factor beta, and interferon gamma expression levels. Besides, miR-124 overexpression decreased CRC cell proliferation and arrested cell cycle at the G1 phase through downregulation of c-Myc and induced apoptosis in CRC cells via upregulation of both intrinsic and extrinsic pathways. Also, miR-124 exogenous overexpression could reduce colony and spheroid formation ability of CRC cells via downregulating CD44 mRNA expression. miR-124 also diminished MMP-9 expression and subsequently suppressed cell migration and invasion. We also illustrated that STAT3 signaling was repressed by miR-124 in CRC cells. Taken together, our findings imply that considering the involvement of miR-124 in the regulation of PD-L1 through colorectal tumorigenesis and its remarkable antitumor effects, this miRNA could be regarded as the promising target for the development of therapeutic approaches for colorectal cancer.

Advances in targeted therapy mainly based on signal pathways for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck region which mainly distributes in southern China and Southeast Asia and has a crucial association with the Epstein-Barr virus. Based on epidemiological data, both incidence and mortality of NPC have significantly declined in recent decades grounded on the improvement of living standard and medical level in an endemic region, in particular, with the clinical use of individualized chemotherapy and intensity-modulated radiotherapy (IMRT) which profoundly contributes to the cure rate of NPC patients. To tackle the challenges including local recurrence and distant metastasis in the current NPC treatment, we discussed the implication of using targeted therapy against critical molecules in various signal pathways, and how they synergize with chemoradiotherapy in the NPC treatment. Combination treatment including targeted therapy and IMRT or concurrent chemoradiotherapy is presumably to be future options, which may reduce radiation or chemotherapy toxicities and open new avenues for the improvement of the expected functional outcome for patients with advanced NPC.

Upregulation of miR-124-3p by Liver X Receptor Inhibits the Growth of Hepatocellular Carcinoma Cells Via Suppressing Cyclin D1 and CDK6

MiR-124-3p has been identified as a novel tumor suppressor and a potential therapeutic target in hepatocellular carcinoma (HCC) through regulating its target genes. However, the upstream regulatory mechanisms of mir-124-3p in HCC has not been fully understood. The transcription factor liver X receptor (LXR) plays a critical role in suppressing the proliferation of HCC cells, but it is unclear whether LXR is involved in the regulation of mir-124-3p. In the present study, we demonstrated that the expression of mir-124-3p was positively correlated with that of LXR in HCC, and the cell growth of HCC was significantly inhibited by LXR agonists. Moreover, activation of LXR with the agonists up-regulated the expression of mir-124-3p, and in turn down-regulated cyclin D1 and cyclin-dependent kinase 6 (CDK6) expression, which are the target genes of mir-124-3p. Mechanistically, miR-124-3p mediates LXR induced inhibition of HCC cell growth and down-regulation of cyclin D1 and CDK6 expression. In vivo experiments also confirmed that LXR induced miR-124-3p expression inhibited the growth of HCC xenograft tumors, as well as cyclin D1 and CDK6 expression. Our findings revealed that miR-124-3p is a novel target gene of LXR, and regulation of the miR-124-3p-cyclin D1/CDK6 pathway by LXR plays a crucial role in the proliferation of HCC cells. LXR-miR-124-3p-cyclin D1/CDK6 pathway may be a novel potential therapeutic target for HCC treatment.

Capn4 contributes to tumor invasion and metastasis in gastric cancer via activation of the Wnt/β-catenin/MMP9 signalling pathways

Capn4, a small regulatory subunit of the calpain proteolytic system, functions as a potential tumor promoter in several cancers. However, the biological functions and molecular mechanisms of Capn4 in gastric cancer (GC) remain poorly understood. In the current study, we found that upregulation of Capn4 was detected frequently in GC tissues, and was associated with significantly worse survival among the GC patients. Multivariate analyses revealed that abundance of Capn4 was an independent predictive marker for the poor prognosis of GC. Further, Capn4 knockdown notably suppressed GC invasion and metastasis in vitro. Consistently, a xenograft assay showed that silencing of Capn4 in GC cells suppressed their dissemination to lung tissue in vivo. Moreover, our results indicated that Capn4 promotes gastric cancer metastasis by increasing MMP9 expression, and demonstrated that MMP9 is crucial for the pro-metastasis role of Capn4 in GC cells. Further investigation revealed that Capn4 regulated MMP9 expression via activation of Wnt/β-catenin signaling pathway. Mechanistically, we found that Capn4 can decreased β-catenin ubiquitination to enhance the protein stability of β-catenin in GC cells. Collectively, Capn4 has a central role in gastric cancer metastasis, which could be a potential diagnostic and therapeutic target for GC.

Lgr5 maintains stemness and regulates cell property in nasopharyngeal carcinoma through Wnt/β-catenin signaling pathway

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in Southern China and Southeast Asia. In this study, we found that Leucine rich repeat containing G protein-coupled receptor 5 (Lgr5) was highly expressed in NPC tissues and marked NPC stem cells. Lgr5high tumors showed differential transcriptional landscape compared to Lgr5not high tumors. Lgr5 expression was associated with the clinicopathologic features in NPC and was able to regulate the stemness and viability of NPC cell line CNE1 and HNE1. Meanwhile, the migration, invasion and epithelial-mesenchymal transition (EMT) was modulated by Lgr5 via Wnt/β-catenin signaling pathway. Furthermore, Lgr5 could regulate the sensitivity of NPC cells to chemotherapy drugs. Xenografted tumors from Lgr5-overexpressed CNE1 cells showed stronger tumor forming capacity and higher expression level of stem cell markers. Thus, we characterized previously unidentified role of Lgr5 in NPC cells, potential serving as a NPC stem cell biomarker and a therapeutic target against NPC.

Bisphenol A triggers the malignancy of nasopharyngeal carcinoma cells via activation of Wnt/β-catenin pathway

It is critical to understand the risk factors responsible for the tumorigenesis and progression of nasopharyngeal carcinoma (NPC). Bisphenol A (BPA) can regulate the estrogenic signals to modulate cancer progression, while its roles in NC were not investigated. Our present study revealed that the BPA can increase proliferation and migration of NPC cells while decrease the chemosensitivity to doxorubicin (Dox). The inhibitor of GSK-3β/β-catenin (LiCl) can restore BPA-induced cell proliferation of NPC cells, which is due to that BPA can decrease phosphorylation while increase expression and nucleus localization of β-catenin. Mechanistically, BPA can increase the mRNA stability of β-catenin (encoded by CTNNB1) via suppressing the expression of miR-214-3p, which can direct target the 3'UTR of β-catenin mRNA. Further, BPA can decrease phosphorylation of β-catenin via repressing the expression of CK1α. Collectively, our data showed that BPA can trigger the proliferation and malignancy of NPC cells via activation of Wnt/β-catenin pathway. It indicated that body accumulation and inhalation exposure of BPA might be a risk factor for NPC development.

miR-124 Intensified Oxaliplatin-Based Chemotherapy by Targeting CAPN2 in Colorectal Cancer

Our previous study demonstrated that miR-124 was downregulated in colorectal cancer (CRC) compared with normal mucosa, and the downregulated expression of miR-124 was an independent prognostic factor in CRC patients. However, the function of miR-124 in CRC patients treated with chemotherapy is currently unclear. The aim of this study was to determine the miR-124 expression and its regulative role in oxaliplatin (L-OHP)-based chemotherapy of CRC patients. We observed that low miR-124 expression was correlated with worse overall survival (OS) in the 220 patients who received postoperative chemotherapy of 5-fluorouracil [5-FU]+leucovorin+L-OHP (FOLFOX) or capecitabine+L-OHP (XELOX). miR-124 overexpression promoted L-OHP-induced, but not 5-FU-induced, cytotoxicity and apoptosis in HT29 and SW480 cells. CAPN2 was a direct target of miR-124, and its protein expression was reduced by forced expression of miR-124. miR-124 inhibited tumorigenesis and promoted OS of mice bearing xenograft tumors, especially upon L-OHP treatment. miR-124 also promoted L-OHP-induced apoptosis and restrained CAPN2 protein expression in xenograft tumors. Our results suggest that miR-124 could be considered as both a predictor of L-OHP-based chemotherapy for personalized treatment and a therapeutic target for CRC.

Calpain Small Subunit 1 Protein in the Prognosis of Cancer Survivors and Its Clinicopathological Correlation

Background/Aims. Calpain small subunit 1 (Capn4) is implicated in tumorigenesis and plays a key role in multiple tumors. This study aimed to fully illustrate the prognostic value of Capn4 protein in cancer patients.

FOXO3a knockdown promotes radioresistance in nasopharyngeal carcinoma by inducing epithelial-mesenchymal transition and the Wnt/β-catenin signaling pathway

Mutations in the forkhead box O 3a (FOXO3a) gene are closely related to the progression of several types of cancers. However, few studies explore the relationship between FOXO3a and nasopharyngeal carcinoma (NPC). Our findings demonstrate that silencing FOXO3a promotes tumor radioresistance of NPC in vitro and in vivo through inducing EMT and activating Wnt/β-catenin signal pathway. These data establish that FOXO3a can be a novel and reliable NPC marker and a potential therapeutic target against NPC.

Redox Regulation of Calpains: Consequences on Vascular Function

SIGNIFICANCE

Calpains (CAPNs) are a family of calcium-activated cysteine proteases. The ubiquitous isoforms CAPN1 and CAPN2 have been involved in the maintenance of vascular integrity, but uncontrolled CAPN activation plays a role in the pathogenesis of vascular diseases. Recent Advances: It is well accepted that chronic and acute overproduction of reactive oxygen species (ROS) is associated with the development of vascular diseases. There is increasing evidence that ROS can also affect the CAPN activity, suggesting CAPN as a potential link between oxidative stress and vascular disease.

CRITICAL ISSUES

The physiopathological relevance of ROS in regulating the CAPN activity is not fully understood but seems to involve direct effects on CAPNs, redox modifications of CAPN substrates, as well as indirect effect on CAPNs via changes in Ca²⁺ levels. Finally, CAPNs can also stimulate ROS production; however, data showing in which context ROS are the causes or the consequences of CAPN activation are missing.

FUTURE DIRECTIONS

Detailed characterization of the molecular mechanisms underlying the regulation of the different members of the CAPN system by specific ROS would help understanding the pathophysiological role of CAPN in the modulation of the vascular function. Moreover, given that CAPNs have been found in different cellular compartments such as mitochondria and nucleus as well as in the extracellular space, identification of new CAPN targets as well as their functional consequences would add new insights in the function of these enigmatic proteases.

MicroRNA-506 inhibits tumor growth and metastasis in nasopharyngeal carcinoma through the inactivation of the Wnt/β-catenin signaling pathway by down-regulating LHX2

Background

Epithelial-mesenchymal transition (EMT)-associated proteins play key roles in cancer progression and metastasis with the involvement of microRNAs (miRNAs). This study aims to assess the role of miR-506 working in tandem with LIM Homeobox 2 (LHX2) in EMT and metastasis through the Wnt/β-catenin signaling pathway in nasopharyngeal carcinoma (NPC).

Methods

Differentially expressed genes associated with NPC were screened using microarray analyses, from which LHX2 was identified. Next, the potential relationship between miR-506 and LHX2 was analyzed. In order to explore the effect of miR-506 or LHX2 on NPC cell proliferation, migration, invasion and apoptosis, serials of mimics, inhibitors or siRNA against LHX2 were transfected into NPC cells. Then, the expression patterns of LHX2, Wnt1, β-catenin, E-cadherin, Vimentin, TCF4 and Twist were determined to assess the influence of miR-506 or LHX2 on EMT as well as the relationship between the Wnt/β-catenin signaling pathway and TCF4. The tumorigenicity and lymph node metastasis (LNM) in xenograft tumors of nude mice were observed.

Results

The has-miR-506-3p was identified as the down-regulated gene in NPC based on the microarray data while LHX2 was negatively regulated by miR-506. Over-expression of miR-506 or silencing of LHK2 inhibited NPC cell proliferation, migration, invasion, tumorigenicity and LNM but promoted apoptosis indicated by decreased Wnt1, β-catenin, Vimentin, TCF4 and Twist expressions along with increased E-cadherin expressions.

Conclusions

miR-506 inhibits tumor growth and metastasis in NPC via inhibition of Wnt/β-catenin signaling by down-regulating LHX2, accompanied by decreased TCF4. Taken together, miR-506 targeted-inhibition LHX2 presents a promising therapeutic strategy for the treatment of NPC.

Trial registration

ChiCTR1800018889. Registered 15 October 2018.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1023-4) contains supplementary material, which is available to authorized users.

Capn4 promotes esophageal squamous cell carcinoma metastasis by regulating ZEB1 through the Wnt/β-catenin signaling pathway

BACKGROUND

Capn4 and ZEB1 play important roles in the metastasis of several types of cancer. However, the roles and relationship of Capn4 and ZEB1 in esophageal squamous cell carcinoma (ESCC) remain unclear.

METHODS

ESCC tumor tissues and corresponding normal esophageal epithelial tissues were obtained from 86 patients undergoing resection surgery at the Department of General Surgery, First Affiliated Hospital of Chinese PLA General Hospital from 2012 to 2017. Cell migration and invasion were examined via quantitative real-time PCR and Western blot assay.

RESULTS

Our results indicate that both Capn4 and ZEB1 are significantly upregulated in ESCC tissues compared to corresponding adjacent tissues, and a positive correlation between expression and associated malignant characteristics was found. Silencing of Capn4 expression markedly inhibited ESCC invasion and metastasis in vitro and in vivo, and was accompanied by decreased ZEB1 expression. Furthermore, the anti-metastasis role of Capn4 silencing was reversed by ZEB1 overexpression, whereas knockdown of ZEB1 decreased ESCC metastasis driven by the upregulation of Capn4. Mechanistically, Capn4 regulated ZEB1 expression via activation of the Wnt/β-catenin signaling pathway in ESCC cells.

CONCLUSION

Overall, our results show that enhanced Capn4 expression activates the Wnt/β-catenin signaling pathway, resulting in increased ZEB1 expression and the promotion of ESCC cell metastasis.

Upregulation of circRNA_0000285 serves as a prognostic biomarker for nasopharyngeal carcinoma and is involved in radiosensitivity

Despite significant medical advancement, nasopharyngeal carcinoma (NPC) remains one of the most difficult types of cancer to detect and treat. Circular RNA (circRNA) signatures may be used as prognostic and predictive factors for cancer. Previous studies indicated that the biological role of circular homeodomain interacting protein kinase 3 (HIPK3) has cancer type-specificity. The HIPK3 gene locus formats three circRNA isoforms: circRNA_100783, circRNA_0000285 and circRNA_100782. However, their roles in NPC remain unknown. In the present study, whether these circRNAs could be used as a biomarker for NPC diagnosis and predicting treatment response was investigated. Reverse transcription-quantitative polymerase chain reaction was performed to measure the levels of circRNA_100783, circRNA_0000285 and circRNA_100782 in NPC and adjacent tissues. In addition, the circRNA_0000285 levels were further confirmed in serum samples from patients with NPC and healthy controls. The results demonstrated that circRNA_0000285, but not circRNA_100782 and circRNA_100783, was significantly increased in NPC tissues and serum samples from patients with NPC, compared with adjacent tissues and serum samples from healthy controls, respectively. Furthermore, circRNA_0000285 expression was increased in patients with radioresistant NPC, compared with patients with radiosensitive NPC. Further analysis demonstrated that circRNA_0000285 was significantly associated with tumor size (P<0.001), differentiation (P=0.022), lymph node metastasis (P=0.035), distant metastasis (P=0.022) and Tumor-Node-Metastasis stage (P<0.001). Additionally, univariate and multivariate analyses indicated that circRNA_0000285 may be an independent prognostic factor for the outcome of patients with NPC. The present data indicated that circRNA_0000285 may be a novel biomarker for NPC and is involved in NPC radiosensitivity.

Downregulation of ribophorin II suppresses tumor growth, migration, and invasion of nasopharyngeal carcinoma

Background

It has been reported that ribophorin II (RPN2) expression is increased in many cancers, but the role of RPN2 in nasopharyngeal carcinoma (NPC) remains unclear.

Patients and methods

This study found that the expression of RPN2 is increased dramatically in NPC tissues of patients compared with that in the adjacent normal tissues. This study attempted at understanding the effect of siRNA-RPN2 treatment on the migration and invasion of NPC cell lines CNE2 and HNE1.

Results

RT-PCR and Western blotting showed that RPN2 was highly expressed in CNE2 and HNE1 cells. siRNA-RPN2 treatment significantly inhibited cell viability at 24 and 48 h compared with the control group. Results of the transwell assay showed that, compared to the control groups, migration and invasion of the cells treated with siRNA-RPN2 decreased markedly. In addition, compared to the control groups, caspase-3, caspase-9, and E-cadherin expression levels increased and MMP 2 expression decreased significantly in the siRNA-RPN2-treated group. Phosphorylation of AKT and PI3K was also inhibited after siRNA-RPN2 treatment.

Conclusion

siRNA-RPN2 can effectively inhibit the invasion and migration of human NPC cells via AKT/PI3K signaling. This can serve as a novel strategy for NPC treatment.

Dynamic Changes in Plasma MicroRNAs Have Potential Predictive Values in Monitoring Recurrence and Metastasis of Nasopharyngeal Carcinoma

Although circulating microRNAs (miRNAs) have already proven to be useful as diagnostic and prognostic biomarkers in nasopharyngeal carcinoma (NPC), the potential of these molecules to monitor patients over time has been less explored. This study aimed to analyze dynamic changes in plasma miRNAs before and after treatment and explore their clinical significance in monitoring recurrence and metastasis of NPC. Candidate miRNAs were screened by microarray analysis and validated by real-time quantitative polymerase chain reaction (RT-qPCR). In the follow-up cohort including 102 patients, blood samples (plasma) were collected before the treatment initiation, 3 months, 6 months, and 12 months after treatments, and at the time of any recurrence or metastasis. Among these plasma miRNAs, miR-9-3p, miR-124-3p, miR-892b, and miR-3676-3p were significantly upregulated (P = 0.018, P = 0.039, P = 0.001, and P = 0.01, resp.) after treatment compared with pretreatment, and the four plasma miRNAs were downregulated again at recurrence or metastasis (P < 0.001, P = 0.015, P = 0.003, and P = 0.026, resp.). The dynamic changes in plasma miRNAs after treatment reflect the outcome of the disease and have the potential to monitor recurrence and metastasis in patients with NPC.

Suppression of Capn4 by microRNA-1271 impedes the proliferation and invasion of colorectal cancer cells

Accumulating evidence has suggested that calpain small subunit 1 (Capn4) plays an important role in the development and progression of malignant tumors. However, little is known about the role of Capn4 in colorectal cancer (CRC). In this study, we aimed to investigate the potential role of Capn4 in CRC and the regulation of Capn4 by microRNAs (miRNAs). Here, we found that Capn4 expression was highly up-regulated in CRC cell lines. Knockdown of Capn4 by siRNA significantly inhibited the proliferation and invasion of CRC cell lines. Furthermore, knockdown of Capn4 suppressed Wnt signaling in CRC cells. Interestingly, Capn4 was found to be a target gene of miR-1271, a tumor suppressive miRNA. The results showed that miR-1271 negatively regulated Capn4 expression in CRC cells. An inverse correlation between miR-1271 and Capn4 was also shown in CRC clinical tissues. Moreover, the overexpression of miR-1271 suppressed the proliferation, invasion and Wnt signaling of CRC cells. Importantly, we found that the restoration of Capn4 expression significantly reversed the antitumor effects of miR-1271 in CRC cells. Overall, these results suggest that miR-1271 inhibits the proliferation and invasion of CRC cells by down-regulating Capn4. Our study suggests that Capn4 and miR-1271 may serve as potential therapeutic targets for the treatment of CRC.

Long noncoding RNA NEAT1 promotes nasopharyngeal carcinoma progression through regulation of miR-124/NF-κB pathway

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies and seriously endangers people's health. Recently, long noncoding RNA (lncRNA) NEAT1 has been determined as an oncogenic gene in a variety of cancers. However, the effect of NEAT1 in NPC and its underlying mechanism have not been well elaborated. In this study, the data showed that NEAT1 was upregulated and miR-124 was downregulated in NPC tissues and cells. Loss-of-function revealed that NEAT1 knockdown inhibited proliferation and promoted apoptosis of NPC cells while gain-of-function revealed that upregulated NEAT1 showed an opposite effect. Moreover, NEAT1 was demonstrated to suppress miR-124 expression by direct interaction in NPC cells. Additionally, miR-124 reversed NEAT1-mediated pro-proliferation and anti-apoptosis effect. Furthermore, miR-124 regulated NPC cell proliferation and apoptosis via NF-κB signal pathway. Mouse models of NPC confirmed that NEAT1 overexpression facilitated tumor growth by modulating miR-124 in vivo. Taken together, this study indicated that upregulated NEAT1 promoted the tumorigenesis and progression of NPC through regulating miR-124/NF-κB signaling pathway, suggesting an attractive therapy target for NPC patients.