MicroRNA-448 suppresses metastasis of pancreatic ductal adenocarcinoma through targeting JAK1/STAT3 pathway

Potential clinical significance of ALDH3B1 in auxiliary diagnosis of gastric cancer

Objective: This research aimed to explore a diagnostic method based on serum ALDH3B1 and to evaluate the clinical diagnostic efficacy in gastric cancer (GC) by comparing it with the traditional GC diagnostic method, the carcinoembryonic protein (CEA) assay. Methods: Serum samples were collected from 70 healthy volunteers and various patients (GC: 76, benign gastric lesions: 20, postoperative: 37, recurrence: 56). The diagnostic efficacy of serum ALDH3B1, CEA and the co-diagnosis were evaluated by receiver operating characteristic curve. ALDH3B1 protein levels were evaluated by western blot. Results: The co-diagnosis of ALDH3B1 and CEA had the highest diagnostic efficacy (area under the curve = 0.841). Conclusion: Serum ALDH3B1 may be used as an auxiliary diagnostic biomarker for GC, and its co-diagnosis with CEA can improve diagnostic efficacy.

The NF-κB/miR-488/ERBB2 axis modulates pancreatic cancer cell malignancy and tumor growth through cell cycle signaling

Pancreatic cancer is one of the malignancies having the poorest prognosis due to late diagnoses and lack of efficient treatment regimens. The identification of potential miRNA-targeted gene axes could act as targets for developing novel treatment strategies. Herein, it was assessed that miR-488 expression was markedly downregulated within pancreatic carcinoma. Higher expression of miR-488 was shown to be linked to better prognosis rates of pancreatic carcinoma as per online data. Within two pancreatic tumor cells, MIA PaCa-2 and PANC-1, miR-488 overexpression significantly suppressed malignant cytological behavior by inhibiting cell viability, enhancing cell apoptosis, and inducing cell cycle G2/M-phase arrest. Moreover, miR-488 overexpression also decreased the protein levels of cell cycle regulators, including cyclin A, cyclin B, CDK1, and CDK2. miR-488 directly targets ERBB2 (receptor tyrosine-protein kinase2) to suppress the expression of ERBB2 by targeting its 3'UTR. ERBB2 knockdown in MIA PaCa-2 and PANC-1 cell lines suppressed, but miR-488 inhibition enhanced the cancer cell biological malignant behavior; the effects of miR-488 inhibition on pancreatic cancer cells were significantly reversed by ERBB2 knockdown. NF-κB suppressed the expression of miR-488 transcriptionally via targeting its promoter region, consequentially repressing the tumor-suppressive effects of miR-488 upon pancreatic tumor cells. Thus, an NF-κB/miR-488/ERBB2 axis modulating pancreatic cancer cell malignancy and tumor growth through cell cycle signaling was conclusively demonstrated.

Role of non-coding RNAs in tumor progression and metastasis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer with an overall 5-year survival rate of less than 10%. The 1-year survival rate of patients with locally advanced or metastatic disease is abysmal. The aggressive nature of cancer cells, hypovascularization, extensive desmoplastic stroma, and immunosuppressive tumor microenvironment (TME) endows PDAC tumors with multiple mechanisms of drug resistance. With no obvious genetic mutation(s) driving tumor progression or metastatic transition, the challenges for understanding the biological mechanism(s) of these processes are paramount. A better understanding of the molecular and cellular mechanisms of these processes could lead to new diagnostic tools for patient management and new targets for therapeutic intervention. microRNAs (miRNAs) are an evolutionarily conserved gene class of short non-coding regulatory RNAs. miRNAs are an extensive regulatory layer that controls gene expression at the posttranscriptional level. This review focuses on preclinical models that functionally dissect miRNA activity in tumor progression or metastatic processes in PDAC. Collectively, these studies suggest an influence of miRNAs and RNA-RNA networks in the processes of epithelial to mesenchymal cell transition and cancer cell stemness. At a cell-type level, some miRNAs mainly influence cancer cell–intrinsic processes and pathways, whereas other miRNAs predominantly act in distinct cellular compartments of the TME to regulate fibroblast and immune cell functions and/or influence other cell types’ function via cell-to-cell communications by transfer of extracellular vesicles. At a molecular level, the influence of miRNA-mediated regulation often converges in core signaling pathways, including TGF-β, JAK/STAT, PI3K/AKT, and NF-κB.

LncRNA SNHG16 promotes epithelial-mesenchymal transition by upregulating ITGA6 through miR-488 inhibition in osteosarcoma

BACKGROUND

Osteosarcoma is a primary cause of cancer-associated death in children and adolescents worldwide. Long non-coding RNAs SNHG16 (lncRNA SNHG16) and integrin subunit-a 6 (ITGA6) are recently reported to be involved in the tumorigenesis of osteosarcoma by multiple mechanisms. However, the correlation between SNHG16 and ITGA6 in osteosarcoma remains undetermined.

METHODS

Expression of miR-488, SNHG16 and ITGA6, as well as epithelial-mesenchymal transition (EMT) associated markers in osteosarcoma tissues and cell lines were examined by qRT-PCR or Western blotting. Effects of miR-488, SNHG16 and ITGA6 on cell migration, invasion were evaluated by wound-healing assay and transwell assay. Bioinformatics analysis and dual-luciferase reported assays were applied to assess the interaction among miR-488, SNHG16 and ITGA6. RNA immunoprecipitation (RIP) was also used to verify SNHG16 and miR-488 interaction. Finally, animal study was used to detect the effect of SNHG16 on osteosarcoma in vivo.

RESULTS

SNHG16 and ITGA6 were significantly increased while miR-488 was decreased in osteosarcoma. ITGA6 was screened as a target gene of miR-488, and SNHG16 was sponged by miR-488 in osteosarcoma cells. MiR-488 overexpression and SNHG16 knockdown suppressed migration, invasion and EMT of osteosarcoma cells. Moreover, rescue assays proved that the influences of SNHG16 on osteosarcoma cells migration, invasion and EMT were dependent on miR-488 and ITGA6. In addition, the promotive effects of SNHG16 on osteosarcoma tumor growth and metastasis were further supported by xenograft tumor growth assay.

CONCLUSION

SNHG16 promoted migration, invasion and EMT of osteosarcoma by sponging miR-488 to release ITGA6.

Crosstalk between miRNAs and signaling pathways involved in pancreatic cancer and pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer-related deaths worldwide with 5-year survival rates below 8%. Most patients with PC and pancreatic ductal adenocarcinoma (PDAC) die after relapse and cancer progression as well as resistance to treatment. Pancreatic tumors contain a high desmoplastic stroma that forms a rigid mass and has a potential role in tumor growth and metastasis. PC initiates from intraepithelial neoplasia lesions leading to invasive cancer through various pathways. These lesions harbor particular changes in signaling pathways involved in the tumorigenesis process. These events affect both the epithelial cells, including the tumor and the surrounding stroma, and eventually lead to the formation of complex signaling networks. Genetic studies of PC have revealed common molecular features such as the presence of mutations in KRAS gene in more than 90% of patients, as well as the inactivation or deletion mutations of some tumor suppressor genes including TP53, CDKN2A, and SMAD4. In recent years, studies have also identified different roles of microRNAs in PC pathogenesis as well as their importance in PC diagnosis and treatment, and their involvement in various signaling pathways. In this study, we discussed the most common pathways involved in PC and PDAC as well as their role in tumorigenesis and progression. Furthermore, the miRNAs participating in the regulation of these signaling pathways in PC progression are summarized in this study. Therefore, understanding more about pathways involved in PC can help with the development of new and effective therapies in the future.

Long Noncoding RNA DUXAP8 Promotes Pancreatic Carcinoma Cell Migration and Invasion Via Pathway by miR-448/WTAP/Fak Signaling Axis

OBJECTIVES

Pancreatic carcinoma (PC) has become the fourth leading cause of cancer deaths. Long noncoding RNA DUXAP8 has also been reported to play a regulatory role in PC progression. However, its molecular mechanism in PC is not fully elucidated.

METHODS

Quantitative real-time polymerase chain reaction was used to detect the levels of DUXAP8, microRNA (miR)-448, Wilms tumor 1-associating protein (WTAP), focal adhesion kinase (Fak), and matrix metallopeptidase 2/9. Western blotting was carried out to detect matrix metallopeptidase 2/9, WTAP, Fak, and p-Fak. The interaction between DUXAP8 and miR-448 as well as WTAP and miR-448 was validated by bioinformatics and dual-luciferase reporter assays. Transwell assay was used to analyze cell invasion and migration. 3-[4,5-Dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay was used to analyze cell proliferation.

RESULTS

DUXAP8 was upregulated, whereas miR-448 was downregulated in PC tissue and cells. Meanwhile, DUXAP8 knockdown or miR-448 overexpression inhibited migration, invasion, and proliferation of PC cells. DUXAP8 directly targeted miR-448, and miR-448 directly bound to WTAP. Downregulation of miR-448 reversed the inhibition of migration and invasion of PC cells by DUXAP8 knockdown.

CONCLUSIONS

DUXAP8 sponges miR-448 to modulate migration, invasion, and proliferation of PC cells, indicating a novel mechanistic role of DUXAP8 in the regulation of PC progression.

MiRNAs directly targeting the key intermediates of biological pathways in pancreatic cancer

Pancreatic Cancer (PC) is a severe form of malignancy all over the world. Delayed diagnosis and chemoresistance are the major factors contributing to its poor prognosis and high mortality rate. The genetic and epigenetic regulations of biological pathways further complicate the progression and chemotherapy response to this cancer. MicroRNAs (MiRNAs) involvement has been observed in all types of cancers including PC. The understanding and categorization of miRNAs according to their specific targets are very important to develop early diagnostic and therapeutic interventions. The current review, emphasizing recent research findings, has categorized miRNAs that directly target the potential onco-factors that act as central converging signal-nodes in five major cancer-related pathways i.e., MAPK/ERK, JAK/STAT, Wnt/β-catenin, AKT/mTOR, and TGFβ in PC. The therapeutic perspectives of miRNAs in PC have also been discussed. This will help to understand the interplay of various miRNAs within foremost signaling pathways and develop a multifactorial approach to treat difficult-to-treat PC.

The antitumor effect of miR-448 in epithelial ovarian cancer

BACKGROUND

Ovarian cancer (OC) is the seventh most commonly diagnosed cancer in the world and the tenth most common in China. Target agents such as bevacizumab and poly (ADP-ribose) polymerase (PARP) inhibitors show efficacy only in the early stages of some cases; therefore, more effective molecular targeting agents need to be developed. microRNAs (miRNA) have emerged as new biomarkers in the clinical diagnosis and treatment of OC. Among these, miRNA-448 has been shown to exert a tumor-suppressor role in numerous cancer types. However, the function of miR-448 in OC remains poorly understood.

METHODS

The miR-448 in cancer tissues and cell lines was tested by quantitative real-time polymerase chain (qRT-PCR). The miR-448 levels were altered by miR-448 mimics (UUGCAUAUGUAGGAUGUCCCAU) or miR-448 antisense oligonucleotide transfection (miR20001532-1-5). Cell growth was evaluated by MTT assay, and cell apoptosis was assayed by annexin V-FITC (detecting apoptotic cells by binding to phosphatidylserine) and propidium iodide (PI, detecting death cells by binding to DNA) (Cat. No. ab54775, Abacam). The target gene of miR-448 was confirmed by dual-luciferase reporter assays.

RESULTS

In this study, we found that miR-448 showed low expression in epithelial ovarian cancer (EOC) tissues and that the low expression of miR-448 was related to low survival rate. miR-448 may thus inhibit cellular proliferation and promote apoptosis by binding the 3'UTR of zinc finger E-box-binding homeobox 2 (ZEB2) and inhibiting the expression of ZEB2.

CONCLUSIONS

Our study suggests that miR-448 has an inhibitory role in OC.

MiR-448 targets BLC2 and inhibits the growth of pituitary adenoma cells

There is an increasing body of evidence indicating the important roles of miRNAs in the progression of pituitary adenoma. Recent studies have shown decreased expression and tumor suppressive function of miR-448 in cancers; however, the clinical significance of miR-448 in pituitary adenoma has remained largely unknown. In our study, we found that miR-448 was down-regulated in pituitary adenoma tissues and cell lines. Overexpression of miR-448 significantly inhibited the proliferation and migration of pituitary adenoma cells. Increased cell apoptosis was also observed with overexpression of miR-448. To further understand the mechanisms behind the regulation of pituitary adenoma by miR-448 in, the targets of miR-448 were predicted using the bioinformatics tools. B cell lymphoma 2 (BCL2) was identified as a target of miR-448. MiR-448 bound the 3'-untranslated region (UTR) of BCL2 and inhibited the expression of BCL2 in pituitary adenoma cells. There was a consistent and significantly negative correlation between the level of miR-448 and BCL2 in pituitary adenoma tissues. When BCL2 was highly expressed, the inhibitory impact of miR-448 on the proliferation and apoptosis of pituitary adenoma cells was significantly inhibited. Collectively, our findings emphasize the significance of the miR-448-BCL2 axis in the development of pituitary adenoma, highlighting the potential therapeutic significance of miR-448 in pituitary adenoma.

Differential Expression of MicroRNAs in Silent and Functioning Corticotroph Tumors

The potential role of miRNAs in the silencing mechanisms of pituitary neuroendocrine tumors (PitNETs) has not been addressed. The aim of the present study was to evaluate the expression levels and the potential associated role of some miRNAs, pathways, and transcription factors in the silencing mechanisms of corticotroph tumors (CTs). Accordingly, the expression of miR-375, miR-383, miR-488, miR-200a and miR-103; of PKA, MAP3K8, MEK, MAPK3, NGFIB, NURR1, PITX1, and STAT3 were analyzed via qRT-PCR in 23 silent and 24 functioning CTs. miR-200a and miR-103 showed significantly higher expression in silent than in functioning CTs, even after eliminating the bias of tumor size, therefore enabling the differentiation between the two variants. Additionally, miR-383 correlated negatively with TBX19 in silent CTs, a transcription factor related with the processing of POMC that can participate in the silencing mechanisms of CTs. Finally, the gene expression levels of miR-488, miR-200a, and miR-103 were significantly higher in macroadenomas (functioning and silent) than in microadenomas. The evidence from this study indicates that miRNAs could be involved in the pathophysiology of CTs. The translational implications of these findings suggest that pharmacological treatments specifically targeting these miRNAs could become a promising therapeutic option for these patients.

Prognostic value of microRNAs in pancreatic cancer: a meta-analysis

BACKGROUND

The prognostic impact of microRNA (miRNA) expression levels in pancreatic cancer (PC) has been estimated for years, but the outcomes are controversial and heterogeneous. Therefore, we comprehensively reviewed the evidence collected on miRNA expression in PC to determine this effect.

RESULTS

PC patients with high miR-21 (HR=2.61, 95%CI=1.68-4.04), miR-451a (HR=2.23, 95%CI=1.23-4.04) or miR-1290 (HR=1.43, 95%CI=1.04-1.95) levels in blood had significantly poorer OS (P<0.05). Furthermore, PC patients with high miR-10b (HR=1.73, 95%CI=1.09-2.76), miR-17-5p (HR=1.91, 95%CI=1.30-2.80), miR-21 (HR=1.90, 95%CI=1.61-2.25), miR-23a (HR=2.18, 95%CI=1.52-3.13), miR-155 (HR=2.22, 95%CI=1.27-3.88), miR-203 (HR=1.65, 95%CI=1.14-2.40), miR-221 (HR=1.72, 95%CI=1.08-2.74), miR-222 levels (HR=1.72, 95%CI=1.02-2.91) or low miR-29c (HR=1.39, 95%CI=1.08-1.79), miR-126 (HR=1.55, 95%CI=1.23-1.95), miR-218 (HR=2.62, 95%CI=1.41-4.88) levels in tissues had significantly shorter OS (P<0.05).

CONCLUSIONS

In summary, blood miR-21, miR-451a, miR-1290 and tissue miR-10b, miR-17-5p, miR-21, miR-23a, miR-29c, miR-126, miR-155, miR-203, miR-218, miR-221, miR-222 had significant prognostic value.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews to recognize eligible studies, and 57 studies comprising 5445 PC patients and 15 miRNAs were included to evaluate the associations between miRNA expression levels and overall survival (OS) up to June 1, 2019. Summary hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the effect.

Long noncoding RNA LINC00657 enhances the malignancy of pancreatic ductal adenocarcinoma by acting as a competing endogenous RNA on microRNA-433 to increase PAK4 expression

A long noncoding RNAs (lncRNA) called LINC00657 is dysregulated and contributes to tumor progression in a number of human cancer types. However, there is limited information on the expression profile and functions of LINC00657 in pancreatic ductal adenocarcinoma (PDAC). The expression profile of LINC00657 in PDAC was estimated by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). The effects of LINC00657 upregulation on PDAC cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo were explored using CCK-8, flow cytometry, Transwell migration and invasion assays, and a xenograft tumor formation experiment, respectively. The results revealed that LINC00657 was evidently upregulated in the PDAC tumors and cell lines. High LINC00657 expression significantly correlated with the pathological T stage, lymph node metastasis, and shorter overall survival. Functional analysis demonstrated that LINC00657 knockdown inhibited the proliferation, migration, and invasion while promoted the apoptosis of PDAC cells. In addition, LINC00657 knockdown markedly suppressed tumor growth of these cells in vivo. In terms of the mechanism, LINC00657 could directly interact with microRNA-433 (miR-433) and effectively worked as an miR-433 sponge, thus decreasing the competitive binding of miR-433 to PAK4 mRNA and ultimately increasing PAK4 expression. The actions of LINC00657 knockdown on malignant phenotype of PDAC cells were strongly attenuated by miR-433 inhibition and PAK4 restoration. These results indicate that LINC00657 promotes PDAC progression by increasing the output of the miR-433-PAK4 regulatory loop, thus highlighting the importance of the LINC00657-miR-433-PAK4 network in PDAC pathogenesis.

Upregulated miR-27a-3p Indicates a Poor Prognosis in Pancreatic Carcinoma Patients and Promotes the Angiogenesis and Migration by Epigenetic Silencing of GATA6 and Activating VEGFA/VEGFR2 Signaling Pathway

Background

Abnormal miR-27a-3p expression has been frequently reported in several types of human cancer and contributes to tumor progression. However, the role and potential molecular mechanism of miR-27a-3p in the progression of pancreatic carcinoma have not been clarified.

Materials and methods

The expression of miR-27a-3p and GATA binding protein 6 (GATA6) in pancreatic carcinoma tissues and cell lines was evaluated by quantitative real-time PCR and Western blotting analysis. The relationship between clinical pathologic features and miR-27a-3p expression was analyzed with Chi-square test. The regulatory mechanism of miR-27a-3p on GATA6 was confirmed by luciferase reporter assay and bioinformatics analysis. The effects of miR-27a-3p by targeting GATA6 on cell angiogenesis and migration were assessed by capillary tube formation and wound healing assays.

Results

MiR-27a-3p expression was significantly upregulated in pancreatic carcinoma tissues and cell lines. Highly expressed miR-27a-3p was closely related to more lymph node metastasis, present peritoneal metastasis, and poor prognosis in patients with pancreatic carcinoma. MiR-27a-3p promoted migration and angiogenesis of pancreatic carcinoma cells by activating vascular endothelial growth factor A (VEGFA) and vascular endothelial growth factor receptor 2 (VEGFR2) expression. A significantly negative correlation between GATA6 mRNA and miR-27a-3 expression was found in pancreatic carcinoma samples. Modulation of miR-27a-3p could alter GATA6 expression in pancreatic carcinoma cells. GATA6 was identified as a functional target gene of miR-27a-3p, and GATA6 knockdown partially reversed the effects of miR-27a-3p siliencing on the migration and angiogenesis of pancreatic carcinoma cells by regulation of VEGFA/VEGFR2 pathway.

Conclusion

Upregulated miR-27a-3p indicates a poor prognosis in pancreatic carcinoma patients and promotes the angiogenesis and migration by epigenetic silencing of GATA6 and activating VEGFA/VEGFR2 signaling pathway, and indicating miR-27a-3p may be a promising therapeutic target for pancreatic carcinoma treatment.

miRNA-448 inhibits cell growth by targeting BCL-2 in hepatocellular carcinoma

BACKGROUND

Increasing evidence indicates that aberrant micro (mi)RNA-448 expression plays a critical role in the progression of several human cancers. However, the function of miRNA-448 in hepatocellular carcinoma (HCC) has not been fully investigated.

METHODS

miRNA-448 expression levels in HCC tissues, adjacent non-cancerous tissues (ANTs), and HCC cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR). HCC cells were treated with a miRNA-448 mimic or inhibitor, followed by cell viability measurements with the CCK-8 assay. Venn diagram analysis predicted, and dual luciferase reporter assays verified, the target gene of miRNA-448. Expression of the target gene was detected by qRT-PCR and immunohistochemistry. Growth of miRNA-448- or target gene-expressing HCC xenograft tumors in nude mice was measured.

RESULTS

miRNA-448 was expressed at a lower level in HCC tissues than ANTs, and correlated with a larger tumor size, incomplete tumor encapsulation, and advanced Barcelona Clinic Liver Cancer stage. miRNA-448 inhibited HCC cell growth. The downstream target of miRNA-448 was BCL-2, which was highly expressed in HCC tissues and its mRNA level was negatively correlated with miRNA-448 expression. In vivo, BCL-2 attenuated the tumor inhibiting effect of miRNA-448.

CONCLUSION

miRNA-448 functions as a tumor suppressor by targeting BCL-2 in HCC.

Modulation of the IL-6-Signaling Pathway in Liver Cells by miRNAs Targeting gp130, JAK1, and/or STAT3

Interleukin-6 (IL-6)-type cytokines share the common receptor glycoprotein 130 (gp130), which activates a signaling cascade involving Janus kinases (JAKs) and signal transducer and activator of transcription (STAT) transcription factors. IL-6 and/or its signaling pathway is often deregulated in diseases, such as chronic liver diseases and cancer. Thus, the identification of compounds inhibiting this pathway is of interest for future targeted therapies. We established novel cellular screening systems based on a STAT-responsive reporter gene (Cypridina luciferase). Of a library containing 538 microRNA (miRNA) mimics, several miRNAs affected hyper-IL-6-induced luciferase activities. When focusing on candidate miRNAs specifically targeting 3′ UTRs of signaling molecules of this pathway, we identified, e.g., miR-3677-5p as a novel miRNA affecting protein expression of both STAT3 and JAK1, whereas miR-16-1-3p, miR-4473, and miR-520f-3p reduced gp130 surface expression. Interestingly, combination treatment with 2 or 3 miRNAs targeting gp130 or different signaling molecules of the pathway did not increase the inhibitory effects on phospho-STAT3 levels and STAT3 target gene expression compared to treatment with single mimics. Taken together, we identified a set of miRNAs of potential therapeutic value for cancer and inflammatory diseases, which directly target the expression of molecules within the IL-6-signaling pathway and can dampen inflammatory signal transduction.

Emerging Roles of Circular RNAs in Osteosarcoma

Osteosarcoma (OS) is a primary malignant bone tumor in early adolescence with high metastasis and death rates. Although the combination of polychemotherapy and surgical excision increased the survival rates up to 60%, the prognosis remains poor for most patients with metastatic or recurrent osteosarcoma. However, the exact pathogenic mechanism and pivotal elements regulating tumor invasion and metastasis are largely unknown. Circular RNAs (circRNAs) are novel endogenous non-coding RNA (ncRNA) molecules that generate the cyclic structure from back splicing. An increasing number of studies show that circRNAs can regulate transcriptional or posttranscriptional gene expression by acting as microRNA (miRNA) sponges and are involved in regulation of many important biological processes. The deregulation of some circRNAs was demonstrated in osteosarcoma. Furthermore, some circRNAs were identified to play essential roles in osteosarcoma occurrence, invasion, and metastasis. This review summarizes the regulatory effect of circRNAs in the occurrence and development of osteosarcoma, concentrating on deregulation, regulatory mechanisms, and functions of circRNAs and their potential value as biomarkers and therapy.

Five key lncRNAs considered as prognostic targets for predicting pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and the 5‐year survival rate was only 7.7%. To improve prognosis, a screening biomarker for early diagnosis of pancreatic cancer is in urgent need. Long non‐coding RNA (lncRNA) expression profiles as potential cancer prognostic biomarkers play critical roles in development of tumorigenesis and metastasis of cancer. However, lncRNA signatures in predicting the survival of a patient with PDAC remain unknown. In the current study, we try to identify potential lncRNA biomarkers and their prognostic values in PDAC. LncRNAs expression profiles and corresponding clinical information for 182 cases with PDAC were acquired from The Cancer Genome Atlas (TCGA). A total of 14 470 lncRNA were identified in the cohort, and 175 PDAC patients had clinical variables. We obtained 108 differential expressed lncRNA via R packages. Univariate and multivariate Cox proportional hazards regression, lasso regression was performed to screen the potential prognostic lncRNA. Five lncRNAs have been recognized to significantly correlate with OS. We established a linear prognostic model of five lncRNA (C9orf139, MIR600HG, RP5‐965G21.4, RP11‐436K8.1, and CTC‐327F10.4) and divided patients into high‐ and low‐risk group according to the prognostic index. The five lncRNAs played independent prognostic biomarkers of OS of PDAC patients and the AUC of the ROC curve for the five lncRNAs signatures prediction 5‐year survival was 0.742. In addition, targeted genes of MIR600HG, C9orf139, and CTC‐327F10.4 were explored and functional enrichment was also conducted. These results suggested that this five‐lncRNAs signature could act as potential prognostic biomarkers in the prediction of PDAC patient's survival.

Downregulation of microRNA-448 inhibits IL-1β-induced cartilage degradation in human chondrocytes via upregulation of matrilin-3

Background

Osteoarthritis is characterized by the continuous degradation of the articular cartilage. The microRNA miR-448 has been found to be broadly involved in cellular processes, including proliferation, apoptosis, invasion and EMT. While aberrant expression of miR-448 has been found in multiple cancers, its level in osteoarthritis cartilage and its role in the progression of this disease are still unknown. Here, we examined the functional roles of miR-448 and its expression in osteoarthritis tissues, including IL-1β-stimulated osteoarthritis chondrocytes.

Methods

Chondrocytes were isolated from human articular cartilage and stimulated with IL-1β. The expression levels of miR-448 in the cartilage and chondrocytes were both determined. After transfection with an miR-448 mimic or inhibitor, the mRNA levels of aggrecan, type II collagen and MMP-13 were determined. Luciferase reporter assay, qRT-PCR and western blot were performed to explore whether matrilin-3 was a target of miR-448. Furthermore, we co-transfected chondrocytes with miR-448 inhibitor and siRNA for matrilin-3 and then stimulated them with IL-1β to determine whether miR-448-mediated IL-1β-induced cartilage matrix degradation resulted from directly targeting matrilin-3.

Results

The level of miR-448 was significantly higher and matrilin-3 expression was significantly lower in osteoarthritis cartilage and IL-1β-induced chondrocytes than in normal tissues and cells. Furthermore, matrilin-3 expression was reduced by miR-448 overexpression. MiR-448 downregulation significantly alleviated the IL-1β-induced downregulation of aggrecan and type II collagen expression, and upregulation of MMP-13 expression. MiR-448 overexpression had the opposite effects. Knockdown of matrilin-3 reversed the effects of the miR-448 inhibitor on the expressions of aggrecan, type II collagen and MMP-13.

Conclusion

The findings showed that miR-448 contributed to the progression of osteoarthritis by directly targeting matrilin-3. This indicates that it has potential as a therapeutic target for the treatment of osteoarthritis.