hsa-miR-141 downregulates TM4SF1 to inhibit pancreatic cancer cell invasion and migration

MicroRNA-141 inhibits tumor growth and metastasis in gastric cancer by directly targeting transcriptional co-activator with PDZ-binding motif, TAZ

Gastric cancer (GC) is a biologically heterogeneous disease accompanying various genetic and epigenetic alterations, and the molecular mechanisms underlying this disease are complex and not completely understood. Increasing evidence shows that abnormal microRNA (miRNA) expression is involved in GC tumorigenesis, but the role of specific miRNAs involved in this disease remains elusive. MiR-141 was previously reported to act as tumor suppressors or oncogenes in diverse cancers. However, their accurate expression, function and mechanism in GC are largely unclear. Here we found that the expression of miR-141 was significantly reduced in GC compared with paired adjacent normal tissues and was significantly correlated with a more aggressive phenotype of GC in patients. Ectopic expression of miR-141 mimics in GC cell lines resulted in reduced proliferation, invasion and migration, and inhibition of miR-141 in GC cell lines promoted cell proliferation, invasion and migration in vitro. We further demonstrated that miR-141 acted as tumor suppressors through targeting transcriptional co-activator with PDZ-binding motif (TAZ) in GC. Moreover, the inverse relationship between miR-141 and its target was verified in patients and xenograft mice. Finally, overexpression of miR-141 suppressed tumor growth and pulmonary metastasis in nude mice. Take together, we identified that miR-141 is a potent tumor suppressor in the stomach, and its growth inhibitory effects are, in part, mediated through its downstream target gene, TAZ. These findings implied that miR-141 might be employed as novel prognostic markers and therapeutic targets of GC.

A pilot study to develop a diagnostic test for pancreatic ductal adenocarcinoma based on differential expression of select miRNA in plasma and bile

OBJECTIVES

Accurate peripheral markers for the diagnosis of pancreatic ductal adenocarcinoma (PDAC) are lacking. We measured the differential expression of select microRNAs (miRNAs) in plasma and bile among patients with PDAC, chronic pancreatitis (CP), and controls.

METHODS

We identified patients (n=215) with treatment-naive PDAC (n=77), CP with bile/pancreatic duct pathology (n=67), and controls (n=71) who had been prospectively enrolled in a Pancreatobiliary Biorepository at the time of endoscopic retrograde cholangiopancreatography or endoscopic ultrasound. Controls were patients with choledocholithiasis but normal pancreata. The sample was separated into training (n=95) and validation (n=120) cohorts to establish and then test the performance of PDAC Signature Panels in diagnosing PDAC. The training cohort (n=95) included age-matched patients with PDAC, CP, and controls. Panels were derived from the differential expression of 10 candidate miRNAs in plasma or bile. We selected miRNAs having excellent accuracy for inclusion in regression models.

RESULTS

Using the training cohort, we confirmed the differential expression of 9/10 miRNAs in plasma (miR-10b, -30c, -106b, -132, -155, -181a, -181b, -196a, and -212) and 7/10 in bile (excluding miR-21, -132, and -181b). Of these, five (miR-10b, -155, -106b, -30c, and -212) had excellent accuracy for distinguishing PDAC. In the training and validation cohorts, the sensitivity/specificity for a PDAC Panel derived from plasma was 95/100% and 100/100%, respectively; in bile, these were 96/100% and 100/100%.

CONCLUSIONS

Increased expression of miRNA-10b, -155, and -106b in plasma appears highly accurate in diagnosing PDAC. Additional studies are needed to confirm this Panel and explore its value as a prognostic test.

microRNA-141 inhibits cell proliferation and invasion and promotes apoptosis by targeting hepatocyte nuclear factor-3β in hepatocellular carcinoma cells

Background

Hepatocyte nuclear factor-3β (HNF-3β) plays a critical role in hepatocyte differentiation and controls liver-specific gene expression during the development of hepatocellular carcinoma (HCC), but the molecular basis of this process has not been fully elucidated. microRNAs (miRNAs) are powerful, post-transcriptional regulators of gene expression. Whether miRNAs can impact the effects of HNF-3β in HCC is still unknown.

Methods

HNF-3β and miR-141 expression levels were detected in HepG2 cells, using real-time quantitative RT-PCR (qRT-PCR). Luciferase reporter assays and Western blots were used to validate HNF-3β as a direct target gene of miR-141. Cell proliferation, invasion, and apoptosis were also examined to confirm whether miR-141 could impact on HNF-3β in HCC.

Results

In this study, we found that HNF-3β protein levels were consistently upregulated in HCC clinical tissues compared with matched normal adjacent tissues. However, the mRNA levels of HNF-3β varied in random tissues, suggesting that a post-transcriptional mechanism was involved in its regulation. We used bioinformatic analyses to search for miRNAs that could potentially target HNF-3β, and identified specific targeting sites for miR-141 in the 3′-untranslated region (3′-UTR) of the HNF-3β gene. By overexpressing miR-141 in HepG2 cells, we experimentally validated that miR-141 directly regulated HNF-3β expression. Furthermore, the biological consequences of targeting HNF-3β by miR-141 were examined using cell proliferation, invasion and apoptosis assays in vitro. We demonstrated that the repression of HNF-3β by miR-141 suppressed the proliferation and invasion and promoted the apoptosis of HepG2 cells.

Conclusions

miR-141 functions as a tumor suppressor in HCC cells through the inhibition of HNF-3β translation.

miR-141 suppresses the growth and metastasis of HCC cells by targeting E2F3

MicroRNAs (miRNAs) function as essential post-transcriptional modulators of gene expression involved in a wide range of physiologic and pathologic states, including cancer. Numerous miRNAs have been deregulated in hepatocellular carcinoma (HCC). Here, we investigated the role of miR-141 in HCC. Decreased expression of miR-141 was observed in both HCC tissues and cell lines. Ectopic overexpression of miR-141 reduced proliferation, migration, and invasion of HCC cells. E2F transcription factor 3 (E2F3) was confirmed to be a target of miR-141 in HCC cells. Moreover, restoration of E2F3 significantly reversed the tumor suppressive effects of miR-141. Our results suggest a critical role of miR-141 in suppressing metastasis of HCC cells by targeting E2F3.

Paeonol suppresses chondrosarcoma metastasis through up-regulation of miR-141 by modulating PKCδ and c-Src signaling pathway

Chondrosarcoma, a primary malignant bone cancer, has potential for local invasion and distant metastasis, especially to the lungs. Patients diagnosed with it show poor prognosis. Paeonol (2'-hydroxy-4'-methoxyacetophenone), the main active compound of traditional Chinese remedy Paeonia lactiflora Pallas, exhibits anti-inflammatory and anti-tumor activity; whether paeonol regulates metastatic chondrosarcoma is largely unknown. Here, we find paeonol do not increase apoptosis. By contrast, at non-cytotoxic concentrations, paeonol suppresses migration and invasion of chondrosarcoma cells. We also demonstrate paeonol enhancing miR-141 expression and miR-141 inhibitor reversing paeonol-inhibited cell motility; paeonol also reduces protein kinase C (PKC)d and c-Src kinase activity. Since paeonol inhibits migration and invasion of human chondrosarcoma via up-regulation of miR-141 via PKCd and c-Src pathways, it thus might be a novel anti-metastasis agent for treatment of metastatic chondrosarcoma.

Helicobacter pylori modulates cisplatin sensitivity in gastric cancer by down-regulating miR-141 expression

BACKGROUND

Recent studies found that gastric cancer patients with Helicobacter pylori infection had a better response to chemotherapy and had an improved overall prognosis compared with those without. However, the underlying mechanism remains unknown.

METHODS

Quantitative real-time PCR (qRT-PCR) was utilized to determine the expression profile of miR-141 in H. pylori infected cells and tissues and their respective controls. qRT-PCR and Western blot were used to determine the expression level of KEAP-1. Luciferase reporter assays were used to determine whether KEAP-1 was a direct target of miR-141 in the gastric cancer cells. MTT and apoptosis assay were performed to detect the survival of cells under cisplatin treatment.

RESULT

We found that H. pylori infection can significantly down-regulate miR-141 expression. Knockdown miR-141 expression in 7901/DDP and 7901 cells could significantly improve cisplatin sensitivity. Over-expression of miR-141 resulted in enhanced resistance to cisplatin in both gastric cancer cells. We also demonstrated that miR-141 directly targets KEAP1 by luciferase reporter assay, and that down-regulation of KEAP1 induces cisplatin resistance. Conversely, over-expression of KEAP1 significantly enhanced cisplatin sensitivity. Our 75 pairs of tissues also showed that KEAP1 was significantly up-regulated in H. pylori-positive tissues.

CONCLUSION

Altogether, these findings demonstrated that the H. pylori infection could modulate cisplatin sensitivity through miR-141-mediated regulation of KEAP1.

Studying the system-level involvement of microRNAs in Parkinson's disease

Background

Parkinson's Disease (PD) is a progressive neurologic disorder that affects movement and balance. Recent studies have revealed the importance of microRNA (miR) in PD. However, the detailed role of miR and its regulation by Transcription Factor (TF) remain unexplored. In this work for the first time we have studied TF-miR-mRNA regulatory network as well as miR co-expression network in PD.

Result

We compared the 204 differentially expressed miRs from microarray data with 73 PD related miRs obtained from literature, Human MicroRNA Disease Database and found a significant overlap of 47 PD related miRs (p-value<0.05). Functional enrichment analyses of these 47 common (Group1) miRs and the remaining 157 (Group2) miRs revealed similar kinds of over-representative GO Biological Processes and KEGG pathways. This strengthens the possibility that some of the Group 2 miRs can have functional roles in PD progression, hitherto unidentified in any study. In order to explore the cross talk between TF, miR and target mRNA, regulatory networks were constructed. Study of these networks resulted in 14 Inter-Regulatory hub miRs whereas miR co-expression network revealed 18 co-expressed hub miRs. Of these 32 hub miRs, 23 miRs were previously unidentified with respect to their association with PD. Hierarchical clustering analysis further strengthens the roles of these novel miRs in different PD pathways. Furthermore hsa-miR-92a appeared as novel hub miR in both regulatory and co-expression network indicating its strong functional role in PD. High conservation patterns were observed for most of these 23 novel hub miRs across different species including human. Thus these 23 novel hub miRs can be considered as potential biomarkers for PD.

Conclusion

Our study identified 23 novel miR markers which can open up new avenues for future studies and shed lights on potential therapeutic targets for PD.