SRT1720 ameliorates sodium taurocholate-induced severe acute pancreatitis in rats by suppressing NF-κB signalling

Severe acute pancreatitis (SAP) is a medical emergency that is often associated with multiple organ failure and high mortality. Although an SAP diagnosis requires prompt treatment, therapeutic options remain limited. SRT1720 is a newly formulatedSIRT1 activator that exerts multiple pharmacological activities with beneficial health effects. However, its potential as an SAP treatment has not been explored. The current study assessed the effect of SRT1720 on a rat model of sodium taurocholate-induced SAP and explored the underlying mechanism. SAP was induced in rats by retrograde injection of a 3.5% sodium taurocholate solution (1 ml/kg) in the biliopancreatic duct. SRT1720 (5 mg/kg) was administered intraperitoneally after sodium taurocholate exposure. Serum samples were analysed for inflammatory cytokine levels and select enzymatic activities using the enzyme-linked immunosorbent assay and commercial enzyme activity assay kits, respectively; protein expression levels were evaluated by western blotting; mRNA levels of biomarkers were determined by quantitative real-time PCR; histopathological changes were analysed by haematoxylin and eosin staining and immunohistochemistry.SRT1720 treatment significantly reduced serum amylase, lipase, pancreatic histological scores, proinflammatory cytokine (TNF-α and IL-6) levels, and expression of NF-κB and p65 in sodium taurocholate-induced SAP rats. Importantly, the treatment stimulated SIRT1 and IκBα levels in pancreatic tissue. Our data suggest that SRT1720 protects rats from sodium taurocholate-induced SAP by suppressing the NF-κB signalling pathway.

BMP14 induces tenogenic differentiation of bone marrow mesenchymal stem cells in vitro

Bone marrow mesenchymal stem cells (BMSCs) are pluripotent cells, which have the capacity to differentiate into various types of mesenchymal cell phenotypes, including osteoblasts, chondroblasts, myoblasts and tendon fibroblasts (TFs). The molecular mechanism for tenogenic differentiation of BMSCs is still unknown. The present study investigated the effects of bone morphogenetic protein (BMP) 14 on BMSC differentiation in vitro. It was revealed that BMP14 significantly increased the expression of tendon markers (scleraxis and tenomodulin) at the mRNA and protein level, which led to the upregulation of sirtuin 1 (Sirt1) expression. The gain or loss of Sirt1 function may promote or inhibit tenogenic differentiation by deacetylating the peroxisome proliferator-activated receptor (PPAR)-γ. BMP14 also triggered the phosphorylation of c-Jun N-terminal kinase (JNK) and Smad1; overexpression of Sirt1 significantly increased the phosphorylation and knockdown of Sirt1 significantly decreased the phosphorylation. The inhibition of JNK and Smad significantly increased the acetylation of PPARγ and inhibited the expression of tenogenic differentiation markers. These results suggest that BMP14 may induce the tenogenic differentiation of BMSCs via the Sirt1-JNK/Smad1-PPARγ signaling pathway. The present study provided a cellular and molecular basis for the development of novel therapeutic strategies for tendon healing.

JNK pathway in osteoarthritis: pathological and therapeutic aspects

CONTEXT

Osteoarthritis (OA) is a common chronic degenerative joint disease resulting in physical disability and reduced quality of life. Different biochemical signaling pathways are involved in the progression of OA, including the c-Jun NH2-terminal kinase (JNK) signal transduction pathway.

OBJECTIVE

In this study, we have reviewed the recent updates on the association of JNK pathway with OA.

METHODS

In this review, we have explored the databases like PubMed, Google Scholar, Medline, Scopus, etc., and collected the most relevant papers of JNK signaling pathway involved in the pathogenesis and therapeutics of OA Results: JNK has been shown by scientific studies to be activated (phosphorylated) in OA that can play a key role in the cartilage destruction. Activation of JNK causes the phosphorylation of c-Jun that causes decreased proteoglycan synthesis and enhanced production of matrix metalloproteinase 13 (MMP-13). Overproduction of MMP-13 by chondrocytes plays a central role in cartilage degeneration in OA. Thus, targeting JNK pathway might be a promising therapeutic application for the prevention and treatment of OA. A number of JNK-inhibitors have been used in vitro and in vivo studies; however, not yet been translated into human use.

CONCLUSIONS

This review study indicates that JNK pathway plays an important role in development and progression of OA, and targeting the JNK pathway might be a potential approach for the treatment of OA in future.

Application of intraoperative transluminal core-biopsy for diagnosis of pancreatic head mass: A single center 15-year experience

BACKGROUND

Pathology is the gold standard for diagnosis of pancreatic cancer. Preoperative endoscopic ultrasound-guided biopsy is an expensive procedure that is not routine in developing countries, hence a cheap, reliable alternative is required.

AIM

To evaluate the effectiveness and safety of a new technique of intraoperative biopsy from pancreatic head mass.

METHODS

Patients undergoing intraoperative transluminal core-biopsy (TLCB) for pancreatic head mass from January 2000 to June 2015 were included in this study. Following Kocher's maneuver, a biopsy was taken from the mass through the duodenum transluminally, using a commercial 16G automatic core-biopsy needle. Multiple tissue specimens were obtained for intraoperative frozen section examination. Depending on the pathological results, a decision was taken to either perform pancreaticoduodenectomy, duodenum-preserving pancreatic head resection, bypass surgery, or to just terminate the operation. The malignancy status of the lesion was confirmed by postoperative pathological examination and/or long-term follow-up of the patients.

RESULTS

A total of 525 patients were included. Intraoperative pathological reports revealed 436 malignant cases and 89 cases without evidence of malignancy. The sensitivity, specificity, false positive rate, and false negative rate were 97.7%, 100%, 0%, and 2.3%, respectively. Complications occurred in 2 patients.

CONCLUSION

TLCB is a quick, safe, effective, and accurate method for intraoperative diagnosis method in patients with pancreatic head mass; it can provide reliable evidence for surgical decision-making.

Thymidine kinase 1 silencing retards proliferative activity of pancreatic cancer cell via E2F1-TK1-P21 axis

OBJECTIVES

Thymidine kinase 1 (TK1) is one of the salvage enzymes engaged in the synthesis of DNA. Although a pro-carcinogenetic role of TK1 has been reported in various types of cancers, its role in pancreatic ductal adenocarcinoma (PDAC) is still unknown. The study is aimed to elaborate the function of TK1 in PDAC and the potential mechanisms in the following study.

MATERIALS AND METHODS

TK1 expression was analysed by immunohistochemistry, real-time PCR and Western blot, and its relationship with clinicopathological characteristics of PDAC patients was further investigated. To verify the function of TK1 and potential mechanism, TK1 siRNA was used to transfect PDAC cells and performed a series of assays in cell and animal models.

RESULTS

The level of TK1 expression was higher in cancerous tissues compared with matched adjacent tissues. TK1 overexpression was associated with progression of PDAC and poor prognosis. Knockdown of TK1 could suppress cell proliferation via inducing S phase arrest mediated by upregulation of P21. Further mechanism investigation suggested that transcription factor E2F-1 could directly regulate the TK1 and promote tumour proliferation.

CONCLUSIONS

The results suggested that TK1 might be involved in the development and progression of PDAC by regulating cell proliferation and show that TK1 may work as a promising therapeutic target in patients with PDAC.

Black pleural effusion due to pancreatic pseudocyst: A case report

RATIONALE

Black pleural effusion (BPE) is an extremely uncommon type of pleural fluid, which can be due to infection, primary or metastatic malignancy, and hemorrhage. As reported in previous studies, BPE is also observed in some patients with pancreatic pseudocyst.

PATIENT CONCERNS

We herein reported a case of a 14-year-old female patient who was admitted to our center with a history of cough for 1 and a half months and right chest pain for 1 month. Before this, she was consecutively hospitalized in 3 different hospitals due to the same symptoms. However, the previous treatments were ineffective due to the lack of a definitive diagnosis. Laboratory examination of the pleural effusion showed BPE with a high amylase concentration. Chest x-ray and computed tomography (CT) showed massive pleural effusion, more prominent in the right chest. CT and MRCP of the abdomen showed a cystic lesion located in the tail of the pancreas, which entered the chest cavity via an esophageal hiatal hernia. DIAGNOSES:: pancreatic pseudocyst.

INTERVENTIONS

After confirming that the tumor was a pancreatic pseudocyst by intraoperative biopsy, internal drainage to the jejunum was performed.

OUTCOMES

The postoperative recovery was rapid and without complications, and the final discharge diagnosis was idiopathic pancreatic pseudocyst (without history of pancreatitis or pancreatic injuries) with BPE of the right chest.

LESSONS

This case demonstrates that massive BPE could present as a rare complication of pancreatic pseudocyst, and surgery is a potential treatment for such patients.

Effect of Retrievable Stent Size on Endovascular Treatment of Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

In clinical practice, stent diameter is one of the variable properties important for endovascular treatment. A consensus guideline for stent retriever size selection has yet to be established. The aim of this study was to investigate the effects of different diameters of Solitaire retrievers on outcomes.

MATERIALS AND METHODS

Of 628 patients enrolled from the Endovascular Treatment for Acute Anterior Circulation Ischemic Stroke Registry, 256 were treated with the Solitaire 4-mm device and 372, with the 6-mm device. We matched patients treated with the 2 stent sizes using propensity score analysis. The successful outcome was reperfusion as measured by the modified Thrombolysis in Cerebral Infarction score immediately postprocedure and the dichotomized modified Rankin Scale score at 90 days. Symptomatic intracerebral hemorrhage and in-hospital mortality were also recorded.

RESULTS

After propensity score analysis, group outcomes did not differ. In addition, in patients with atherosclerosis-related occlusion, a higher reperfusion rate (P = .021) was observed in the Solitaire 4 group, as well as a shorter time interval (P = .002) and fewer passes (P = .025). Independent predictors of successful reperfusion in patients with atherosclerotic disease on logistic analysis were the small stent (OR, 3.217; 95% CI, 1.129-9.162; P = .029) and the propensity score acting as a covariate (OR, 52.84; 95% CI, 3.468-805.018; P = .004).

CONCLUSIONS

We found no evidence of a differential effect of intra-arterial therapy based on the size of Solitaire retrievers. In patients with atherosclerotic disease, favorable reperfusion was associated with deployment of a small stent.

MALAT1/miR-127-5p Regulates Osteopontin (OPN)-Mediated Proliferation of Human Chondrocytes Through PI3K/Akt Pathway

Osteoarthritis (OA) is characterized by progressive destruction of articular cartilage, resulting in significant disability. Chondrocytes present in various types of cartilage and are responsible for the growth and maintenance of the tissue. Over-proliferation of human chondrocytes may contributes to OA pathological process. Previously, we revealed that miR-127-5p could inhibit the proliferation of human chondrocytes through osteopontin (OPN). In the present study, we used online tools to figure out several candidates lncRNAs which were potentially correlated with miR-127-5p. Through assessing the expression levels of the candidates lncRNAs, metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was chosen as a further research subject. MALAT1 knockdown significantly repressed human OA chondrocyte proliferation, as well as the protein levels of OPN, p-PI3K, and p-Akt in OA chondrocytes. As verified by luciferase assays, MALAT1 directly bound to miR-127-5p to inhibit miR-127-5p expression. Then we achieved miR-127-5p inhibition through miR-127-5p inhibitor transfection; the miR-127-5p inhibition could promote chondrocyte proliferation, as well as the protein levels of OPN, p-PI3K, and p-Akt; in addition, the MALAT1 knockdown partially reversed the promotive effect of miR-127-5p inhibition on chondrocyte proliferation, OPN and PI3K/Akt signaling-related protein levels. Taken together, MALAT1 could directly bind to miR-127-5p to inhibit its expression, so as to rescue OPN expression and promote chondrocyte proliferation through PI3K/Akt pathway. Targeting MALAT1 so as to rescue miR-127-5p expression in OA might help to inhibit chondrocyte proliferation through miR-127-5p-mediated OPN regulation and downstream PI3K/Akt pathway. J. Cell. Biochem. 119: 431-439, 2018. © 2017 Wiley Periodicals, Inc.

[Laparoscopic pancreaticoduodenectomy with a novel artery first and uncinate process first approach through Treitz ligament]

Objective: To explore the clinical effect of a novel artery first and uncinate process first approach for laparoscopic pancreaticoduodenectomy(LPD), emphasizing the left lateral and posterior dissection of uncinate process (UP) via Treitz ligament approach. Methods: From April to November 2016, 18 patients received LPD with a novel approach in Pancreas Center of the First Affiliated Hospital with Nanjing Medical University. All patients were diagnosed as pancreatic head or peri-ampulla tumor, without major vessel invasion nor distant metastasis. For resection, routine caudal view was used in the first step, to dissect the anterior medial border between uncinate process and superior mesenteric vein(SMV). Lymphatic tissues were completely dissected form anterior surface of hepatoduodenal ligament. In the second step, left lateral view with camera from left para-umbilical trocar was used, Treitz ligament was incised, SMA root was exposed. After anticlockwise rotation and retraction of mesentery, the anatomic relationship between SMA trunk, inferior pancreaticoduodenal artery(IPDA), jejunal branch of SMV, and distal part of UP, could be perfectly exposed from left lateral view. SMA was dissected from its root until the position above the uncinate process and duodenum, IPDA was transected, distal part of UP was freed from SMA. In the third step, right lateral view and caudal view were alternatively used; proximal UP mesentery was completely dissected out from SMA root, CA root and posterior surface of hepatoduodenal ligament. Pancreaticoduodenectomy was completed in the forth step after transection of pancreatic neck and common hepatic duct. Results: The SMA root and distal UP were successfully dissected out via Treitz ligament approach in all 18 patients, among them, distal UP was completely excised in 8 patients from left view. Postoperative pathology showed R0 resection rate in 69%. Postoperative complication included intra-abdominal hemorrhage in 1 patient, pancreatic fistula in 7 patients(6 cases with grade A and 1 case with grade B), delayed gastric emptying in 4 patients (2 cases with grade A, 2 cases with grade B). Average postoperative hospital stay was (15.5±6.8)days. Conclusion: The novel artery first and uncinate process first approach through Treitz ligament could help surgeons to completely dissect the full length of meso-pancreas along celiac axis-SMA axis in LPD.

PRSS1 and SPINK1 Mutations in Alcoholic and Idiopathic Chronic Pancreatitis

Several recent studies have reported associations between gene mutations and chronic pancreatitis (CP); however, little is known about their association with risk of CP in the Chinese Han population. The aim of this study was to describe mutations in the cationic trypsinogen (PRSS1) and serine protease inhibitor Kazal type 1 (SPINK1) genes in patients with alcoholic chronic pancreatitis (ACP) and idiopathic chronic pancreatitis (ICP) and to investigate their influence on the clinical course of the disease. One hundred patients (24 with ACP, 76 with ICP) and 100 healthy volunteers (control group) were enrolled in the study. PRSS1 (R122H) mutations were detected in one (1.3%) patient with ICP and SPINK1 (N34S) mutations were present in one (4.1%) patient with ACP. PRSS1 and SPINK1 mutations were not detected in the control populations. There were no statistically significant differences between the CP patients and the control group. Those preliminary data suggest low prevalence of SPINK1 and PRSS1 mutations in the Chinese population, generally, as well as in CP patients, indicating that these mutations do not contribute to the development of CP.

Vasohibin 2 reduces chemosensitivity to gemcitabine in pancreatic cancer cells via Jun proto-oncogene dependent transactivation of ribonucleotide reductase regulatory subunit M2

Background

Vasohibin 2 (VASH2) has previously been identified as an agiogenenic factor and a cancer related protein. Here we investigated the association of VASH2 expression and chemoresistance in pancreatic cancer.

Methods

Immunohistochemical staining for VASH2 was performed on 102 human pancreatic cancer samples. Pancreatic cancer cell line models exhibiting overexpression or knockdown of VASH2 were generated. Gene expression analyses were carried out to determine genes differentially regulated by VASH2. Putative transcription factors that are downstream mediators of gene expression regulated by VASH2 were queried bioinformatically. Dual-luciferase reporter assays and ChIP assays were performed to confirm transactivation of target genes following VASH2 overexpression or knockdown.

Results

VASH2 protein expression was higher in human pancreatic cancer than in paired adjacent tissues and elevated VASH2 levels were associated with gemcitabine chemoresistance. In cell line models of pancreatic cancer, VASH2 expression induced gemcitabine chemoresistance in vitro and in vivo. It was discovered that expression of ribonucleotide reductase regulatory subunit M2 (RRM2) is regulated by VASH2; immunohistochemical analysis demonstrated a positive association of VASH2 expression and RRM2 expression in human pancreatic cancer tissues. Bioinformatics analyses revealed that induction of the Jun proto-oncogene (JUN) by VASH2 is responsible for upregulation of RRM2 expression; this JUN-dependent regulation of RRM2 by VASH2 was confirmed by chromatin immunoprecipitation and dual luciferase reporter assays, which demonstrated that JUN directly binds with the RRM2 promoter to activate transcription.

Conclusions

These data suggest that VASH2 reduces the chemosensitivity to gemcitabine in pancreatic cancer cells via JUN-dependent transactivation of RRM2.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0619-6) contains supplementary material, which is available to authorized users.

Pathological and Therapeutic Aspects of Long noncoding RNAs in osteosarcoma

BACKGROUND

Osteosarcoma (OS) is a common bone malignant tumor, which is the eighth leading form of pediatric cancer. Despite the modern chemotherapeutic development of OS, a number of patients with OS have a high risk of lung metastasis and local relapse after chemotherapy.

OBJECTIVE

This review study focused on the role of long non coding RNAs (lncRNAs) in OS progression, and presented update reports on OS treatment by targeting specific lncRNAs.

METHOD

We have acquired information on OS and lncRNAs from scientific databases like google scholar, pubmed and scopus, and reviewed for this study.

RESULTS

The lncRNAs regulate a number of biological processes, and abnormal expression of lncRNAs could play role in many cancers and other human diseases. Interestingly, some lncRNAs can act as oncogenes, while some act as tumor suppressor genes. A number of studies revealed that targeting the specific lncRNAs by RNA interferance technology may provide a novel therapeutic strategy in the treatment of OS.

CONCLUSION

LncRNAs could be a promising biomarker and might be a potential therapeutic target in OS patients.

[A Classification Algorithm for Epileptic Electroencephalogram Based on Wavelet Multiscale Analysis and Extreme Learning Machine]

The automatic classification of epileptic electroencephalogram(EEG)is significant in the diagnosis and therapy of epilepsy.A classification algorithm for epileptic EEG based on wavelet multiscale analysis and extreme learning machine(ELM)is proposed in this paper.Firstly,wavelet multiscale analysis is applied to the original EEG to extract its sub-bands.Then,two nonlinear methods,i.e.Hurst exponent(Hurst)and sample entropy(SamEn)are used to the feature extraction of EEG and its sub-bands.Finally,ELM algorithm is employed in epileptic EEG classification with the nonlinear features.The proposed method in this paper achieved 99.5% classification accuracy for the discrimination between epileptic ictal and interictal EEG.The result implies that this method has good prospects in the diagnosis and therapy of epilepsy.

Vasohibin 2 promotes epithelial-mesenchymal transition in human breast cancer via activation of transforming growth factor β 1 and hypoxia dependent repression of GATA-binding factor 3

Vasohibin 2 (VASH2) is identified as an angiogenic factor, and has been implicated in tumor angiogenesis, proliferation and epithelial-mesenchymal transition (EMT). To investigate the EMT role of VASH2 in breast cancer, we overexpressed or knocked down expression of VASH2 in human breast cancer cell lines. We observed that VASH2 induced EMT in vitro and in vivo. The transforming growth factor β1 (TGFβ1) pathway was activated by VASH2, and expression of a dominant negative TGFβ type II receptor could block VASH2-mediated EMT. In clinical breast cancer tissues VASH2 positively correlated with TGFβ1 expression, but negatively correlated with E-cadherin (a marker of EMT) expression. Under hypoxic conditions in vitro or in vivo, we found that down-regulation of estrogen receptor 1 (ESR1) in VASH2 overexpressing ESR1 positive cells suppressed E-cadherin. Correlation coefficient analysis indicated that VASH2 and ESR1 expression were negatively correlated in clinical human breast cancer tissues. Further study revealed that a transcription factor of ESR1, GATA-binding factor 3 (GATA3), was down-regulated by VASH2 under hypoxia or in vivo. These findings suggest that VASH2 drives breast cancer cells to undergo EMT by activation of the TGFβ1 pathway and hypoxia dependent repression GATA3-ESR1 pathway, leading to cancer metastasis.

MicroRNA-199a-5p inhibits cisplatin-induced drug resistance via inhibition of autophagy in osteosarcoma cells

Osteosarcoma (OS) is the most common cancer of the bone. Chemotherapy is commonly used for the clinical treatment of OS. However, chemoresistance to cisplatin [also known as diamminedichloridoplatinum (II) (DDP)] is a major obstacle for OS therapy, the underlying mechanism of which is not fully understood. The present study aimed to investigate the role of microRNA (miR)-199a-5p in the regulation of chemoresistance to DDP in OS cells. Reverse transcription-quantitative polymerase chain reaction demonstrated that the expression level of miR-199a-5p was significantly reduced in human OS MG63 cells. In addition, DDP treatment also upregulated the protein levels of light chain 3 (LC3)-II and Beclin1 as well as the ratio of LC3-II vs. LC3-I in MG63 cells, indicating that autophagy was activated. Restoration of miR-199a-5p expression promoted DDP-induced inhibition of MG63 cell proliferation and inhibited DDP-induced autophagy, as indicated by the reduced protein levels of LC3-II and Beclin1 and the ratio of LC3-II vs. LC3-I. Finally, luciferase reporter assay data revealed that miR-199a-5p directly targeted Beclin1 and negatively mediated Beclin1 expression at a post-transcriptional level in MG63 cells. In conclusion, our study suggests that miR-199a-5p promotes the cytotoxicity of DDP in OS cells via inhibition of autophagy. Therefore, miR-199a-5p/autophagy signaling is involved in chemoresistance and may become a potential target for the treatment of DDP-resistant OS.

Comparison of patency rates and clinical impact of different reconstruction methods following portal/superior mesenteric vein resection during pancreatectomy

INTRODUCTION

Few studies have compared patency rates of the different methods of venous reconstruction (VR) during a pancreatectomy. This study aimed to evaluate the patency rates and the clinical impact of various reconstruction methods.

METHODS

For the meta-analysis, databases were systematically searched to identify studies reporting the outcomes of patients who underwent PVR/SMVR. For the retrospective study, clinical data were retrospectively analyzed from patients who underwent a pancreatectomy and VR between Feb. 2009 and Oct. 2015. Patency was assessed by CT and/or ultrasound.

RESULTS

For the meta-analysis, the long-term patency rates of the primary repair group and the autologous graft group were significantly higher than that of the synthetic graft group. For the retrospective study, the reconstruction consisted of primary repair in 62 cases (89.8%) and synthetic grafting in 7 cases (10.1%). Synthetic grafting was more likely to cause acute thrombosis compared with primary repair for PVR/SMVR (85.7% versus 16.7%). Acute thrombosis was associated with decreased median survival (12 versus 6 months) and increased hazard of death. Late thrombosis and stenosis were not associated with survival or serious clinical impact. Median survival for the primary repair group and the synthetic grafting group was 12 and 7 months, respectively.

CONCLUSION

Primary repair following PVR/SMVR is preferred and can be achieved in most situations. Stenosis should be noted when with risk factors (long segmental and tension), but it produced little clinical impact. Synthetic grafting was associated with a higher thrombosis rate. Acute thrombosis is associated with increased mortality and decreased survival.

[Progress on the Rule of Clavicle Epiphyseal Closure Using Multi-Imaging Technology]

People aged 18 years could be punished lightly or diminished criminal responsibility, even be spared the death sentence, which has important meaning in Chinese judicatory adjudication. The epiphysis of long bones from human limbs and the secondary sexual characteristics almost have developed completely before 18 years old. Clavicle epiphysis is one of the articular metaphysis which has a late epiphyseal closure. The recent studies in exploring the rule of clavicle epiphyseal by multi-imaging technology shows that the development of clavicle epiphysis has some value in age estimation of 18 years old. CT, especially thin-section CT, is widely used at present. However, thin-section CT scanning has great net radiation, which is not ethically acceptable if it is not for diagnosis and treatment. MRI is nonradioactive tomographic imaging and easy to evaluate, which is one of the future research directions in forensic age estimation using the medial clavicle. This paper summarizes the progress on the rule of clavicle epiphyseal closure, and analyzes and summarizes the feasibility of rule of clavicle epiphyseal closure applies on age estimation.

MicroRNA-200b acts as a tumor suppressor in osteosarcoma via targeting ZEB1

Osteosarcoma is the most common type of cancer that develops in bone, mainly arising from the metaphysis of the long bones. MicroRNA (miR)-200b has been found to generally act as a tumor suppressor in multiple types of human cancers. However, the detailed role of miR-200b in osteosarcoma still remains to be fully understood. This study aimed to investigate the exact role of miR-200b in the progression of osteosarcoma and the underlying mechanism. Real-time reverse transcription-polymerase chain reaction data showed that miR-200b was significantly downregulated in osteosarcoma tissues compared to their matched adjacent nontumor tissues. Low miR-200b level was associated with the advanced clinical stage and positive distant metastasis. Besides, it was also downregulated in osteosarcoma cell lines (U2OS, Saos2, HOS, and MG63) compared to normal osteoblast cell line NHOst. In vitro study showed that restoration of miR-200b led to a significant decrease in proliferation, migration, and invasion of osteosarcoma cells. Moreover, ZEB1 was identified as a target gene of miR-200b, and its expression levels were negatively mediated by miR-200b in osteosarcoma cells. In addition, ZEB1 was significantly upregulated in osteosarcoma cells compared to the normal osteoblast cell line NHOst, and inhibition of ZEB1 expression also suppressed the proliferation, migration, and invasion in osteosarcoma cells. Finally, we showed that ZEB1 was frequently upregulated in osteosarcoma tissues compared to their matched adjacent normal tissues, and its expression was reversely correlated to the miR-200b levels in osteosarcoma tissues. Based on these findings, our study suggests that miR-200b inhibits the proliferation, migration, and invasion of osteosarcoma cells, probably via the inhibition of ZEB1 expression. Therefore, miR-200b/ZEB1 may become a potential target for the treatment of osteosarcoma.

MicroRNA-127-5p regulates osteopontin expression and osteopontin-mediated proliferation of human chondrocytes

The aim of this study was to determine the specific microRNA (miRNA) that regulates expression of osteopontin (OPN) in osteoarthritis (OA). The potential regulatory miRNAs for OPN messenger RNA (mRNA) were predicted by miRNA prediction programs. Among eight potential regulatory miRNAs, miR-220b, miR-513a-3p and miR-548n increased, while miR-181a, miR-181b, miR-181c, miR-181d and miR-127-5p decreased in OA patients. miRNA-127-5p mimics suppressed OPN production as well as the activity of a reporter construct containing the 3'-UTR of human OPN mRNA. In addition, mutation of miR-127-5p binding site in the 3'-UTR of OPN mRNA abolished miR-127-5p-mediated repression of reporter activity. Conversely, treatment with miR-127-5p inhibitor increased reporter activity and OPN production. Interestingly, miR-127-5p inhibited proliferation of chondrocytes through OPN. In conclusion, miRNA-127-5p is an important regulator of OPN in human chondrocytes and may contribute to the development of OA.