MicroRNA in pancreatic adenocarcinoma: predictive/prognostic biomarkers or therapeutic targets?

Circulating MicroRNAs as Noninvasive Diagnostic and Prognostic Biomarkers in Pancreatic Cancer: A Review

Pancreatic cancer (PC) is one of the most lethal human cancers. Currently, most PC cases are diagnosed at an already advanced stage. Early detection of PC is critical to improving survival rates. Therefore, there is an urgent need to identify biomarkers for the early detection of PC. Recently, circulating miRNAs in whole blood and other body fluids have been reported as promising biomarkers for the early detection of various cancers, including PC. Furthermore, due to minimal invasiveness and technical availability, circulating miRNAs hold promise for further wide usage. As a potential novel molecular marker, circulating miRNAs not only represent promising noninvasive diagnostic and prognostic tools but could also improve the evaluation of tumor classification, metastasis, and curative effect. The purpose of this review is to outline the available information regarding circulating miRNAs as biomarkers for the early detection of PC.

MiR-30a-5p inhibits cell behaviors in esophageal cancer via modulating CBX2

BACKGROUND

This investigation studied the impacts of the miR-30a-5p/CBX2 axis on esophageal cancer (EC).

METHODS

Research objects were ascertained using The Cancer Genome Atlas database. Followed by qRT-PCR, western blot, dual-luciferase reporter, MTT, Transwell, and wound healing approaches, we tested gene expression and varying cell behaviors RESULTS: Conspicuously miR-30 family members (miR-30a-5p, miR-30b-5p, miR-30c-5p, miR-30d-5p, miR-30e-5p) downregulation and CBX2 upregulation were discovered in EC cells. miR-30 family members target CBX2 and inhibited CBX2 expression. EC cell behaviors were inhibited by miR-30a-5p/CBX2 axis.

CONCLUSION

MiR-30a-5p draws a new inspiration for EC treatment.

Prognostic implications of microRNA-21 overexpression in pancreatic ductal adenocarcinoma: an international multicenter study of 686 patients

Despite progress in genomic characterization, no single prognostic marker that can be evaluated using an easy-to-perform and relatively inexpensive method is available for pancreatic ductal adenocarcinoma (PDAC). MicroRNAs, which are stable, tumor- and tissue-specific molecules, are potentially ideal biomarkers, and we established an inter-laboratory validated method to investigate miR-21 as a prognostic biomarker in PDAC. The study samples of PDAC patients were recruited from a test cohort of Glasgow (n = 189) and three validation cohorts of Pisa (n = 69), Sydney (n = 249), and International Cancer Genome Consortium (ICGC) (n = 249). Tissue microarrays were used for miR-21 staining by chromogenic in situ hybridization (CISH). The patients were subdivided into no/low and high miR-21 staining groups using a specific histoscore. Furthermore, miR-21 staining was evaluated against clinicopathological variables and follow-up data by Fisher/log-rank test and Cox proportional models. The prognostic variables found to be significant in univariate analysis (P value < 0.10) were included in multivariate analysis in a backward-stepwise fashion. MiR-21 expression was cytoplasmic, with more consistent staining in the malignant ductal epithelium than in the stroma. The expression of miR-21 was significantly associated with tumor size and lymph node metastasis, whereas no association was observed with other clinicopathological variables. High miR-21 staining (histoscore ≥ 45 [median score]) was an independent predictor of survival in the Glasgow test cohort (HR 2.37, 95% CI: 1.42-3.96, P < 0.0001) and three validation cohorts (Pisa, HR 2.03, 95% CI: 1.21-3.39, P = 0.007; Sydney, HR 2.58, 95% CI (1.21-3.39), P < 0.0001; and ICGC, HR 3.34, 95% CI: 2.07-5.84, P = 0.002) when adjusted for clinical variables in a multivariate model. In comparison to the patients with low miR-21, the patients with high miR-21 expression had significant increase in OS as they benefit from gemcitabine-based adjuvant chemotherapy (Glasgow 16.5 months [with chemotherapy] vs 10.5 months [without chemotherapy]); Sydney 25.0 vs 10.6; ICGC 25.2 vs 11.9. These results indicated that miR-21 is a predictor of survival, prompting prospective trials. Evaluation of miR-21 offers new opportunities for the stratification of patients with PDAC and might facilitate the implementation of clinical management and therapeutic interventions for this devastating disease.

An Exosomal miRNA Biomarker for the Detection of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a difficult tumor to diagnose and treat. To date, PDAC lacks routine screening with no markers available for early detection. Exosomes are 40-150 nm-sized extracellular vesicles that contain DNA, RNA, and proteins. These exosomes are released by all cell types into circulation and thus can be harvested from patient body fluids, thereby facilitating a non-invasive method for PDAC detection. A bioinformatics analysis was conducted utilizing publicly available miRNA pancreatic cancer expression and genome databases. Through this analysis, we identified 18 miRNA with strong potential for PDAC detection. From this analysis, 10 (MIR31, MIR93, MIR133A1, MIR210, MIR330, MIR339, MIR425, MIR429, MIR1208, and MIR3620) were chosen due to high copy number variation as well as their potential to differentiate patients with chronic pancreatitis, neoplasms, and PDAC. These 10 were examined for their mature miRNA expression patterns, giving rise to 18 mature miRs for further analysis. Exosomal RNA from cell culture media was analyzed via RTqPCR and seven mature miRs exhibited statistical significance (miR-31-5p, miR-31-3p, miR-210-3p, miR-339-5p, miR-425-5p, miR-425-3p, and miR-429). These identified biomarkers can potentially be used for early detection of PDAC.

Inferring human miRNA–disease associations via multiple kernel fusion on GCNII

Increasing evidence shows that the occurrence of human complex diseases is closely related to the mutation and abnormal expression of microRNAs(miRNAs). MiRNAs have complex and fine regulatory mechanisms, which makes it a promising target for drug discovery and disease diagnosis. Therefore, predicting the potential miRNA-disease associations has practical significance. In this paper, we proposed an miRNA–disease association predicting method based on multiple kernel fusion on Graph Convolutional Network via Initial residual and Identity mapping (GCNII), called MKFGCNII. Firstly, we built a heterogeneous network of miRNAs and diseases to extract multi-layer features via GCNII. Secondly, multiple kernel fusion method was applied to weight fusion of embeddings at each layer. Finally, Dual Laplacian Regularized Least Squares was used to predict new miRNA–disease associations by the combined kernel in miRNA and disease spaces. Compared with the other methods, MKFGCNII obtained the highest AUC value of 0.9631. Code is available at https://github.com/cuntjx/bioInfo.

Evaluation of Serum microRNA Let-7c and Let-7d as Predictive Biomarkers for Metastatic Pancreatic Cancer

BACKGROUND

First-line treatments for metastatic pancreatic cancer are chemotherapy regimens consisting of 5-fluorouracil or gemcitabine; however, there are no biomarkers to help determine which patients might benefit from which treatment regimens. We aimed to show that microRNAs let-7c and 7d can be used as independent predictive biomarkers for metastatic pancreatic cancer.

METHODS

A total of 55 patients who had first-line chemotherapy with FOLFIRINOX or gemcitabine+capecitabine were included. Patients were divided into groups based on let-7c and let-7d levels and chemotherapy treatment as let-7c-7d high FOLFIRINOX, let7c-7d high gemcitabine+capecitabine, let-7c-7d low FOLFIRINOX, and let-7c-7d low gemcitabine+capecitabine. Blood samples were taken from patients before chemotherapy for microRNA let-7c and 7d analysis. MicroRNA isolation was performed using a miRNeasy Serum/Plasma Kit and identified using spectrophotometric measurements. After isolation, microRNA was converted to cDNA using a microRNA cDNA Synthesis Kit with poly (A) polymerase tailing. The expression of microRNA was examined using quantitative real-time polymerase chain reaction.

RESULTS

The overall survival of patients who received FOLFIRINOX treatment with a high let-7c-7d level was statistically significantly longer than those who received gemcitabine+capecitabine with a high let-7c-7d level. In addition, patients with low let-7c expression receiving FOLFIRINOX progressed significantly 2.104 times earlier than patients with high let-7c expression receiving FOLFIRINOX.

CONCLUSION

The serum MicroRNA let-7c level was found to be an independent predictive biomarker in the FOLFIRINOX treatment group.

Targeting of Mcl-1 Expression by MiRNA-3614-5p Promotes Cell Apoptosis of Human Prostate Cancer Cells

MicroRNA (miRNA) acts as a critical regulator of growth in various human malignancies. However, the role of miRNA-3614 in the progression of human prostate cancer remains unknown. In this study, our results demonstrated that miRNA-3614-5p exerts a significant inhibitory effect on cell viability and colony formation and induces sub-G1 cell cycle arrest and apoptosis in human prostate cancer cells. Myeloid cell leukemia-1 (Mcl-1) acts as a master regulator of cell survival. Using the miRNA databases, miRNA-3614-5p was found to regulate Mcl-1 expression by targeting positions of the Mcl-1-3′ UTR. The reduction of Mcl-1 expression by miRNA-3614-5p was further confirmed using an immunoblotting assay. Pro-apoptotic caspase-3 and poly (ADP-ribose) polymerase (PARP) were significantly activated by miRNA-3614-5p to generate cleaved caspase-3 (active caspase-3) and cleaved PARP (active PARP), accompanied by the inhibited Mcl-1 expression. These findings were the first to demonstrate the anti-growth effects of miRNA-3614-5p through downregulating Mcl-1 expression in human prostate cancer cells.

MiRNA-disease association prediction based on meta-paths

Since miRNAs can participate in the posttranscriptional regulation of gene expression, they may provide ideas for the development of new drugs or become new biomarkers for drug targets or disease diagnosis. In this work, we propose an miRNA-disease association prediction method based on meta-paths (MDPBMP). First, an miRNA-disease-gene heterogeneous information network was constructed, and seven symmetrical meta-paths were defined according to different semantics. After constructing the initial feature vector for the node, the vector information carried by all nodes on the meta-path instance is extracted and aggregated to update the feature vector of the starting node. Then, the vector information obtained by the nodes on different meta-paths is aggregated. Finally, miRNA and disease embedding feature vectors are used to calculate their associated scores. Compared with the other methods, MDPBMP obtained the highest AUC value of 0.9214. Among the top 50 predicted miRNAs for lung neoplasms, esophageal neoplasms, colon neoplasms and breast neoplasms, 49, 48, 49 and 50 have been verified. Furthermore, for breast neoplasms, we deleted all the known associations between breast neoplasms and miRNAs from the training set. These results also show that for new diseases without known related miRNA information, our model can predict their potential miRNAs. Code and data are available at https://github.com/LiangYu-Xidian/MDPBMP.

Translating complexity and heterogeneity of pancreatic tumor: 3D in vitro to in vivo models

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive type of cancer with an overall survival rate of less than 7-8%, emphasizing the need for novel effective therapeutics against PDAC. However only a fraction of therapeutics which seemed promising in the laboratory environment will eventually reach the clinic. One of the main reasons behind this low success rate is the complex tumor microenvironment (TME) of PDAC, a highly fibrotic and dense stroma surrounding tumor cells, which supports tumor progression as well as increases the resistance against the treatment. In particular, the growing understanding of the PDAC TME points out a different challenge in the development of efficient therapeutics - a lack of biologically relevant in vitro and in vivo models that resemble the complexity and heterogeneity of PDAC observed in patients. The purpose and scope of this review is to provide an overview of the recent developments in different in vitro and in vivo models, which aim to recapitulate the complexity of PDAC in a laboratory environment, as well to describe how 3D in vitro models can be integrated into drug development pipelines that are already including sophisticated in vivo models. Hereby a special focus will be given on the complexity of in vivo models and the challenges in vitro models face to reach the same levels of complexity in a controllable manner. First, a brief introduction of novel developments in two dimensional (2D) models and ex vivo models is provided. Next, recent developments in three dimensional (3D) in vitro models are described ranging from spheroids, organoids, scaffold models, bioprinted models to organ-on-chip models including a discussion on advantages and limitations for each model. Furthermore, we will provide a detailed overview on the current PDAC in vivo models including chemically-induced models, syngeneic and xenogeneic models, highlighting hetero- and orthotopic, patient-derived tissues (PDX) models, and genetically engineered mouse models. Finally, we will provide a discussion on overall limitations of both, in vitro and in vivo models, and discuss necessary steps to overcome these limitations to reach an efficient drug development pipeline, as well as discuss possibilities to include novel in silico models in the process.

Tumor Suppressive Effects of miR-124 and Its Function in Neuronal Development

MicroRNA-124 (miR-124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR-124 promoter region and adsorption of miR-124 by non-coding RNAs, miR-124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR-124 due to its promising tumor-suppressive effects; however, the overview of their results is unclear. We surveyed the tumor-suppressive effect of miR-124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR-124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR-124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR-124 exerts its anti-tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR-124 in neuronal development, we found that the miR-124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial-mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR-124.

MicroRNA-202 suppresses glycolysis of pancreatic cancer by targeting hexokinase 2

Purpose: Various studies have identified miR-202 critically participated in the development of different cancers. However, the potential mechanisms underlying the carcinogenesis of pancreatic cancer (PC) still remains elusive. Methods: In the study, cell proliferation assay, colony formation assay, EdU incorporation assay, Luciferase reporter assay, lactate production, glucose consumption assay, real-time PCR and western blot were used to investigate the mechanism of hexokinase 2 (HK2) regulated by miR-202 in pancreatic cancer in vitro and in vivo. Results: Here we found that miR-202 was decreased in the PC tissues, and its low expression was correlated with a poor prognosis of PC patients. Overexpression of miR-202 in PC cells reduced cell proliferation and tumorigenesis by impairing glycolysis, while downregulation of miR-202 promoted the cells proliferative capacity. Mechanically, we demonstrated that HK2, an enzyme that catalyzes the irreversible rate-limiting step of glycolysis, as the direct target of miR-202. Overexpression of miR-202 suppressed both the mRNA and protein levels of HK2, whereas re-introduction of HK2 abrogated miR-202-mediated glycolytic inhibition. In addition, the expression of miR-202 was negatively associated with HK2 level in a cohort of PC tissues. Conclusion: Our findings validate the mechanism that miR-202 reprograms the metabolic process to promote PC progression, thus providing potential prognostic predictors for PC patients.

Tumor-Derived Exosomal miR-620 as a Diagnostic Biomarker in Non-Small-Cell Lung Cancer

Background

Evidence has suggested the functional role of exosomal miRNAs in cancer diagnosis. This study aimed to determine whether the serum exosomal biomarkers can improve the diagnosis of patients with non-small-cell lung cancer (NSCLC).

Materials and Methods

The exosomes were extracted from the serum of NSCLC patients (n = 235) and healthy donors (n = 231) using ultracentrifugation and then were evaluated by using transmission electron microscopy, qNano, and western blotting. The serum exosomal miRNA expression was validated using qPCR.

Results

Exosomal miR-620 was significantly reduced in NSCLC and early-stage NSCLC patients (P < 0.0001) when compared to that of healthy controls, with an area under the curve (AUC) of 0.728 and 0.707, respectively. Exosomal miR-620 expression showed an association with drinking (P=0.008) and distant metastasis (P=0.037). Additionally, the downregulated exosomal miR-620 showed association with chemotherapeutic effect (P=0.044).

Conclusion

These findings suggest the serum exosomal miR-620 as a promising diagnostic and prognostic noninvasive biomarker in NSCLC patients.

MicroRNAs and lncRNAs-A New Layer of Myeloid-Derived Suppressor Cells Regulation

Myeloid-derived suppressor cells (MDSCs) constitute an important component in regulating immune responses in several abnormal physiological conditions such as cancer. Recently, novel regulatory tumor MDSC biology modulating mechanisms, including differentiation, expansion and function, were defined. There is growing evidence that miRNAs and long non-coding RNAs (lncRNA) are involved in modulating transcriptional factors to become complex regulatory networks that regulate the MDSCs in the tumor microenvironment. It is possible that aberrant expression of miRNAs and lncRNA contributes to MDSC biological characteristics under pathophysiological conditions. This review provides an overview on miRNAs and lncRNAs epiregulation of MDSCs development and immunosuppressive functions in cancer.

Paper-based electrochemical peptide nucleic acid (PNA) biosensor for detection of miRNA-492: a pancreatic ductal adenocarcinoma biomarker

Pancreatic ductal adenocarcinoma is the predominant neoplastic disease of the pancreas and it represents the fourth most frequent cause of death in cancer-related disease, with only 8% of survivors after 5-year to the diagnosis. The main issues of this type of cancer rely on fast progress (i.e. 14 months from T1 to a T4 stage), nonspecific symptoms with delay in diagnosis, and the absence of effective screening strategies. To address the lack of early diagnosis, we report a cost-effective paper-based biosensor for the detection of miRNA-492, which is recognised as a biomarker for pancreatic ductal adenocarcinoma. To design a miniaturised, sensitive, and robust paper-based platform, an electrochemical sensor was screen-printed on office paper previously wax-patterned via wax-printing technique. The paper-based sensor was then engineered with a novel and highly specific peptide nucleic acid (PNA) as the recognition element. The formation of PNA/miRNA-492 adduct was evaluated by monitoring the interaction between the positively charged ruthenium (III) hexamine with uncharged PNA and/or negatively charged PNA/miRNA-492 duplex by differential pulse voltammetry. The paper-based biosensor provided a linear range up to 100 nM, with a LOD of 6 nM. Excellent selectivity towards one- and two-base mismatches (1MM, 2MM) or scrambled (SCR) sequences was highlighted and the applicability for biomedical analyses was demonstrated, measuring miRNA-492 in undiluted serum samples.

Bioinformatics-Based Identification of a circRNA-miRNA-mRNA Axis in Esophageal Squamous Cell Carcinomas

Background

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis due to the lack of early disease symptoms. Using bioinformatics tools, this study aimed to discover differentially expressed nonprotein-coding RNAs and genes with potential prognostic relevance in ESCC.

Methods

Two microRNAs (miRNAs) and one circular RNA (circRNA) microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differential expression of miRNAs (DEMs) and circRNAs (DECs) was, respectively, identified in ESCC tissue and compared to adjacent healthy tissue. Further analysis was performed using the miRNA microarray datasets, where miRTarBase was used to predict which messenger RNAs (mRNAs) was present. This was followed by protein-protein interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Ontology (GO) analyses. Moreover, cytoHubba and UALCAN were used to predict the important nodes and perform patient survival analysis, respectively. The miRNA-associated circRNAs were predicted using the ENCORI website. The interaction between DECs and the predicted circRNAs was also determined. A circRNA-miRNA-mRNA axis was constructed.

Results

Associated with RAP1B and circ_0052867, two miRNAs (miR-133b and miR-139-5p) were identified as being differentially expressed and downregulated across the two datasets. Finally, the circ_0052867/miR-139-5p/RAP1B regulatory axis was established.

Conclusion

This study provides support for the possible mechanisms of disease progression in ESCC.

MiR-331-3p Links to Drug Resistance of Pancreatic Cancer Cells by Activating WNT/β-Catenin Signal via ST7L

Background:

Pancreatic cancer is an aggressive type of cancer with poor prognosis, short survival rate, and high mortality. Drug resistance is a major cause of treatment failure in the disease. MiR-331-3p has been reported to play an important role in several cancers. We previously showed that miR-331-3p is upregulated in pancreatic cancer and promotes pancreatic cancer cell proliferation and epithelial-to-mesenchymal transition–mediated metastasis by targeting ST7L. However, it is uncertain whether miR-331-3p is involved in drug resistance.

Methods:

We investigated the relationship between miR-331-3p and pancreatic cancer drug resistance. As part of this, microRNA mimics or inhibitors were transfected into pancreatic cancer cells. Quantitative polymerase chain reaction was used to detect miR-331-3p expression, and flow cytometry was used to detect cell apoptosis. The Cell Counting Kit-8 assay was used to measure the IC50 values of gemcitabine in pancreatic cancer cells. The expression of multidrug resistance protein 1, multidrug resistance-related protein 1, breast cancer resistance protein, β-Catenin, c-Myc, Cyclin D1, Bcl-2, and Caspase-3 was evaluated by Western blotting.

Results:

We confirmed that miR-331-3p is upregulated in gemcitabine-treated pancreatic cancer cells and plasma from chemotherapy patients. We also confirmed that miR-331-3p inhibition decreased drug resistance by regulating cell apoptosis and multidrug resistance protein 1, multidrug resistance-related protein 1, and breast cancer resistance protein expression in pancreatic cancer cells, whereas miR-331-3p overexpression had the opposite effect. We further demonstrated that miR-331-3p effects in drug resistance were partially reversed by ST7L overexpression. In addition, overexpression of miR-331-3p activated Wnt/β-catenin signaling in pancreatic cancer cells, and ST7L overexpression restored activation of Wnt/β-catenin signaling.

Conclusions:

Taken together, our data demonstrate that miR-331-3p contributes to drug resistance by activating Wnt/β-catenin signaling via ST7L in pancreatic cancer cells. These data provide a theoretical basis for new targeted therapies in the future.

miR-3609 Decelerates the Clearance of Sorafenib in Hepatocellular Carcinoma Cells by Targeting EPAS-1 and Reducing the Activation of the Pregnane X Receptor Pathway

Background

The pregnane X receptor (PXR) not only plays an important role in cellular metabolism processes but also induces the resistance of hepatocellular carcinoma (HCC) cells to molecularly targeted drugs by mediating their metabolism and clearance by these cells. Endothelial PAS domain-containing protein 1 (EPAS-1) acts as a coactivator to regulate the transcription factor activity of PXR. In the present study, a microRNA that potentially targets EPAS-1, namely miR-3609, was identified using the miRDB tool.

Methods

The expression of miR-3609 and EPAS-1 was examined by qPCR. Lentiviral particles containing the full-length sequences of miR-3609 (pri-miR-3609) were prepared. The antitumor effect of antitumor agents was examined by the in vitro and in vivo assays.

Results

The expression of miR-3609 was negatively correlated with that of EPAS-1 in both HCC clinical specimens and paired non-tumor specimens, and the effect of miR-3609 on the expression of EPAS-1 was confirmed by Western blot experiments. Overexpression of miR-3609 decreased the expression of EPAS-1 and, in turn, repressed the activation of the PXR pathway. miR-3609 decreased the transcription factor activation of PXR, repressed its recruitment to its target gene promoter regions, and decreased the expression of its target genes CYP3A4 and P-GP. In addition, miR-3609 decelerated the metabolism and clearance of sorafenib in HCC cells and enhanced the antitumor effect of sorafenib in HCC cells.

Conclusion

Therefore, the results indicate that miR-3609 decreases the expression of EPAS-1 and enhances the sensitivity of HCC cells to sorafenib.

Preclinical mouse models for immunotherapeutic and non-immunotherapeutic drug development for pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is in urgent need of better diagnostic and therapeutic methods due to its late diagnosis, limited treatment options and poor prognosis. Finding the right animal models to recapitulate the tumor molecular pathogenesis and tumor microenvironment (TME) complexity is critical for preclinical immunotherapeutic and non-immunotherapeutic treatment developments. In this review, we summarize and evaluate popular preclinical animal models including patient-derived xenograft models, humanized mouse models, genetically engineered mouse models, and syngeneic mouse models. Through comparisons between these models in different research settings, we hope to provide guidance in finding the most relevant preclinical models to suit various research purposes.

A Functional Variant of the miR-15 Family Is Associated with a Decreased Risk of Esophageal Squamous Cell Carcinoma

MicroRNAs (miRNAs)-related single-nucleotide polymorphisms (SNPs) have been shown to be implicated in the susceptibility to different types of cancer, including esophageal squamous cell carcinoma (ESCC). Identification of miRNA-related SNPs may provide candidate biomarkers for early diagnosis of ESCC. We performed a genome-wide microarray assay to identify differentially expressed miRNAs, which indicated that the miR-15 family may play an important role in ESCC biology. We then investigated the association of miR-15 family-related SNPs with ESCC. Five miR-15 family-related SNPs were genotyped in 300 patients and 418 controls. Unconditional logistic regression was used to evaluate the relationships of these SNPs with ESCC. Generalized multifactor dimensionality reduction was employed to analyze the SNP-SNP and SNP-smoking interactions. The expression quantitative trait loci (eQTL) databases were queried for in silico functional validation. We found that miR-15b SNP rs1451761T>G was associated with a significantly decreased risk of ESCC and there was a significant SNP-SNP interaction between rs1451761 and rs2740545. SNP-smoking interaction analysis also indicated that the association between rs1451761 and ESCC risk could be changed by smoking status. Additionally, the eQTL analysis revealed that rs1451761 was significantly correlated with structural maintenance of chromosomes 4 and karyopherin subunit alpha 4 mRNA expression. Our results suggest that miR-15b SNP rs1451761 may affect an individual's susceptibility to ESCC, alone and in SNP-SNP and SNP-smoking interaction manners.

MiR-144: A New Possible Therapeutic Target and Diagnostic/Prognostic Tool in Cancers

MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers.

miR-455-3p Functions as a Tumor Suppressor by Restraining Wnt/β-Catenin Signaling via TAZ in Pancreatic Cancer

Background

Pancreatic cancer (PC) is a highly invasive tumor with a poor prognosis, short overall survival rate and few chemotherapeutic choices. Despite the importance of finding ways to treat pancreatic cancer, the mechanisms of tumor progression have not been fully elucidated. microRNA-455-3p (miR-455-3p) has been reported to play an important role in several cancers, but its function in pancreatic cancer remains unclear.

Methods

To investigate the biological functions, miRNAs mimics or inhibitors were transfected into pancreatic cancer cells. Flow cytometry was used to detect cell apoptosis. Wound healing and Transwell assays were employed to observe cell invasion and migration abilities. The expression of Bcl-2, Bax, caspase-3, E-cadherin, N-cadherin, Snail, β-Catenin, c-Myc and Cyclin D1 were evaluated by qPCR and Western blot.

Results

We confirmed that inhibition of miR-455-3p decreases cell apoptosis and increases cell migration, invasion and EMT of pancreatic cancer, whereas forced overexpression of miR-455-3p has the opposite effect. Furthermore, we demonstrated that the tumor suppression effects of miR-455-3p were partially reversed by TAZ overexpression. In addition, miR-455-3p led to inactivation of Wnt/β-catenin signaling in pancreatic cancer cells, and TAZ overexpression restored the inhibition of Wnt/β-catenin signaling.

Conclusion

Taken together, our data demonstrated that miR-455-3p functions as an important tumor suppressor that suppresses the Wnt/β-catenin signaling pathway via TAZ to inhibit tumor progression in pancreatic cancer. We conclude that the miR-455-3p/TAZ/Wnt axis may be a potential therapeutic target for pancreatic cancer.

Are ENT1/ENT1, NOTCH3, and miR-21 Reliable Prognostic Biomarkers in Patients with Resected Pancreatic Adenocarcinoma Treated with Adjuvant Gemcitabine Monotherapy?

Evidence on equilibrative nucleoside transporter 1 (ENT1) and microRNA-21 (miR‑21) is not yet sufficiently convincing to consider them as prognostic biomarkers for patients with pancreatic ductal adenocarcinoma (PDAC). Here, we investigated the prognostic value of ENT1/ENT1, miR-21, and neurogenic locus homolog protein 3 gene (NOTCH3) in a well-defined cohort of resected patients treated with adjuvant gemcitabine chemotherapy (n = 69). Using a combination of gene expression quantification in microdissected tissue, immunohistochemistry, and univariate/multivariate statistical analyses we did not confirm association of ENT1/ENT1 and NOTCH3 with improved disease-specific survival (DSS). Low miR-21 was associated with longer DSS in patients with negative regional lymph nodes or primary tumor at stage 1 and 2. In addition, downregulation of ENT1 was observed in PDAC of patients with high ENT1 expression in normal pancreas, whereas NOTCH3 was upregulated in PDAC of patients with low NOTCH3 levels in normal pancreas. Tumor miR‑21 was upregulated irrespective of its expression in normal pancreas. Our data confirmed that patient stratification based on expression of ENT1/ENT1 or miR‑21 is not ready to be implemented into clinical decision-making processes. We also conclude that occurrence of ENT1 and NOTCH3 deregulation in PDAC is dependent on their expression in normal pancreas.

Predictive and Prognostic Factors in HCC Patients Treated with Sorafenib

Sorafenib is an oral kinase inhibitor that enhances survival in patients affected by advanced hepatocellular carcinoma (HCC). According to the results of two registrative trials, this drug represents a gold quality standard in the first line treatment of advanced HCC. Recently, lenvatinib showed similar results in terms of survival in a non-inferiority randomized trial study considering the same subset of patients. Unlike other targeted therapies, predictive and prognostic markers in HCC patients treated with sorafenib are lacking. Their identification could help clinicians in the daily management of these patients, mostly in light of the new therapeutic options available in the first.

Targeting Rho GTPase effector p21 activated kinase 4 (PAK4) suppresses p-Bad-microRNA drug resistance axis leading to inhibition of pancreatic ductal adenocarcinoma proliferation

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and therapy resistant malignancy. Mutant K-Ras, found in >90% of refractory PDAC, acts as a molecular switch activating Rho GTPase signaling that in turn promotes a plethora of pro-survival molecules and oncogenic microRNAs. We investigated the impact of Rho GTPase effector protein p21 activated kinase 4 (PAK4) inhibition on pro-survival p-Bad and oncogenic miRNA signaling. We demonstrate that the dual NAMPT and PAK4 modulators (KPT-9274 and KPT-9307) inhibit PDAC cell proliferation through downregulation of Bad phosphorylation and upregulation of tumor suppressive miRNAs (miR-145, let-7c, let-7d, miR-34c, miR320 and miR-100). These results suggest that targeting PAK4 could become a promising approach to restore pro-apoptotic function of Bad and simultaneously activate tumor suppressive miRNAs in therapy resistant PDAC.

Differential MicroRNA Expression Profiles as Potential Biomarkers for Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a clinical challenge due to its poor prognosis. Therefore, the early diagnosis of PDAC is extremely important for achieving a cure. MicroRNAs (miRNAs) could serve as a potential biomarker for the early detection and prognosis of PDAC. In this work we analyzed plasma samples from healthy persons and PDAC patients to assess differential miRNA expression profiles by next generation sequencing technology and bioinformatics analysis. In this way, 165 mature miRNAs were found to be significantly deregulated in the patient group, of which 75 and 90 mature miRNAs were up- and down-regulated compared with healthy individuals, respectively. Furthermore, 1029 novel miRNAs were identified. In conclusion, plasma miRNA expression profiles are different between healthy individuals and patients with PDAC. These data provide a possibility for use of miRNA as diagnostic and prognostic biomarkers of PDAC.

Dinitrosopiperazine-decreased PKP3 through upregulating miR-149 participates in nasopharyngeal carcinoma metastasis

Nasopharyngeal carcinoma (NPC) has a high metastatic clinicopathological feature. As a carcinogen factor, N,N'-dinitrosopiperazine (DNP) is involved in NPC metastasis, but its precise mechanism has not been fully elucidated. Herein, we showed that DNP promotes NPC metastasis through upregulating miR-149. DNP was found to decrease Plakophilin3 (PKP3) expression, further DNP-decreased PKP3 was verified to be through upregulating miR-149. We also found that DNP induced proliferation, adhesion, migration and invasion of NPC cell, which was inhibited by miR-149-inhibitor. DNP may promote NPC metastasis through miR-149-decreased PKP3 expression. Therefore, DNP-increased miR-149 expression may be an important factor of NPC high metastasis, and miR-149 may serve as a molecular target for anti-metastasis therapy of NPC.

K-ras mutation analysis of residual liquid-based cytology specimens from endoscopic ultrasound-guided fine needle aspiration improves cell block diagnosis of pancreatic ductal adenocarcinoma

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) technology is widely used for the diagnosis of pancreatic masses. However, in some cases, inadequate tissue volume or difficulty of morphological diagnosis are constraining factors for adequate cytopathological evaluation. K-ras mutation is the most frequently acquired genetic abnormality, occurring in approximately 90% of all patients with pancreatic ductal adenocarcinoma (PDAC). In the present study, the clinical utility of residual liquid-based cytology (LBC) specimens obtained using EUS-FNA for K-ras mutation analysis was evaluated.

Methods

In this study, 81 patients with pancreatic lesions were examined. The cell block (CB) specimens separated from EUS-FNA samples were morphologically evaluated by hematoxylin–eosin (HE) staining. Final diagnoses were confirmed by CB specimens, surgical resection specimens, diagnostic imaging, and clinical follow-up. Genomic DNA of residual LBC specimens stored at 4°C for several months were extracted and assessed for K-ras mutations using a fluorescence resonance energy transfer-based preferential homoduplex formation assay.

Results

K-ras mutation analysis using residual LBC samples was successful in all cases. The sensitivity, specificity, and accuracy of CB examination alone were 77.4%, 100%, and 81.3%, respectively, and those of the combination of CB examination and K-ras mutation analysis were 90.3%, 92.3%, and 90.7%, respectively. Furthermore, K-ras mutations were detected in 8 (57.1%) of 14 PDAC samples for which the CB results were inconclusive.

Conclusion

These findings suggest that K-ras mutation analysis using residual LBC specimens improves the diagnostic accuracy of EUS-FNA.

Computational identification of microRNAs associated to both epithelial to mesenchymal transition and NGAL/MMP-9 pathways in bladder cancer

Bladder cancer is one of the leading cancer of the urinary tract. It is often diagnosed at advanced stage of the disease. To date, no specific and effective early detection biomarkers are available. Cancer development and progression are associated with the involvement of both epithelial-mesenchymal transition (EMT) and tumor microenvironment of which NGAL/MMP-9 complex represents the main player in bladder cancer. It is known that change in microRNAs (miRNAs) expression may result in gene modulation. Therefore, the identification of specific miRNAs associated with EMT pathway and NGAL/MMP-9 complex may be useful to detect the development of bladder cancer at early stages.

On this ground, the expression levels of miRNAs in public available datasets of bladder cancer containing data of non-coding RNA profiling was evaluated. This analysis revealed a group of 16 miRNAs differentially expressed between bladder cancer patients and related healthy controls. By miRNA prediction tool (mirDIP), the relationship between the identified miRNAs and the EMT genes was established. Using the DIANA-mirPath (v.2) software, miRNAs, able to modulate the expression of NGAL and MMP-9 genes, were recognized.

The results of this study provide evidence that the downregulated hsa-miR-145-5p and hsa-miR-214-3p may modulate the expression of both EMT and NGAL/MMP-9 pathways. Therefore, further validation analyses may confirm the usefulness of these selected miRNAs for predicting the development of bladder cancer at the early stage of the disease.

MicroRNA-1291 targets the FOXA2-AGR2 pathway to suppress pancreatic cancer cell proliferation and tumorigenesis

Pancreatic cancer is the fourth leading cause of cancer death in the United States. Better understanding of pancreatic cancer biology may help identify new oncotargets towards more effective therapies. This study investigated the mechanistic actions of microRNA-1291 (miR-1291) in the suppression of pancreatic tumorigenesis. Our data showed that miR-1291 was downregulated in a set of clinical pancreatic carcinoma specimens and human pancreatic cancer cell lines. Restoration of miR-1291 expression inhibited pancreatic cancer cell proliferation, which was associated with cell cycle arrest and enhanced apoptosis. Furthermore, miR-1291 sharply suppressed the tumorigenicity of PANC-1 cells in mouse models. A proteomic profiling study revealed 32 proteins altered over 2-fold in miR-1291-expressing PANC-1 cells that could be assembled into multiple critical pathways for cancer. Among them anterior gradient 2 (AGR2) was reduced to the greatest degree. Through computational and experimental studies we further identified that forkhead box protein A2 (FOXA2), a transcription factor governing AGR2 expression, was a direct target of miR-1291. These results connect miR-1291 to the FOXA2-AGR2 regulatory pathway in the suppression of pancreatic cancer cell proliferation and tumorigenesis, providing new insight into the development of miRNA-based therapy to combat pancreatic cancer.

The role of miRNAs in the diagnosis, chemoresistance, and prognosis of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a very challenging malignancy with late presentation, metastatic potential, chemoresistance, and poor prognosis. Therefore, there is an urgent need for novel diagnostic and prognostic biomarkers. miRNAs are small noncoding RNAs that regulate the expression of multitude number of genes. Aberrant expression of miRNAs has been linked to the development of various malignancies, including PDAC. A series of miRNAs have been defined as holding promise for early diagnostics, as indicators of therapy resistance, and even as markers for prognosis in PDAC patients. In this review, we summarize the current knowledge on the role of miRNAs in diagnosis, chemoresistance, and prognosis in PDAC patients.

Combined microRNA and mRNA microfluidic TaqMan array cards for the diagnosis of malignancy of multiple types of pancreatico-biliary tumors in fine-needle aspiration material

Pancreatic ductal adenocarcinoma (PDAC) continues to carry the lowest survival rates among all solid tumors. A marked resistance against available therapies, late clinical presentation and insufficient means for early diagnosis contribute to the dismal prognosis. Novel biomarkers are thus required to aid treatment decisions and improve patient outcomes.

We describe here a multi-omics molecular platform that allows for the first time to simultaneously analyze miRNA and mRNA expression patterns from minimal amounts of biopsy material on a single microfluidic TaqMan Array card. Expression profiles were generated from 113 prospectively collected fine needle aspiration biopsies (FNAB) from patients undergoing surgery for suspect masses in the pancreas. Molecular classifiers were constructed using support vector machines, and rigorously evaluated for diagnostic performance using 10×10fold cross validation. The final combined miRNA/mRNA classifier demonstrated a sensitivity of 91.7%, a specificity of 94.5%, and an overall diagnostic accuracy of 93.0% for the differentiation between PDAC and benign pancreatic masses, clearly outperfoming miRNA-only classifiers. The classification algorithm also performed very well in the diagnosis of other types of solid tumors (acinar cell carcinomas, ampullary cancer and distal bile duct carcinomas), but was less suited for the diagnostic analysis of cystic lesions.

We thus demonstrate that simultaneous analysis of miRNA and mRNA biomarkers from FNAB samples using multi-omics TaqMan Array cards is suitable to differentiate suspect solid pancreatic masses with high precision.

Prognostic microRNAs and their potential molecular mechanism in pancreatic cancer: A study based on The Cancer Genome Atlas and bioinformatics investigation

Although certain biomarkers that are directly associated with the overall survival (OS) of patients with pancreatic adenocarcinoma (PAAD) have been identified, the efficacy of a single factor is limited to predicting the prognosis. The aim of the present study was to identify a combination micro (mi)RNA signature that enhanced the prognostic prediction for PAAD. Following analysis of the data available from The Cancer Genome Atlas (TCGA), 175 PAAD samples were selected for the present study, and the associations between 494 miRNAs and OS were investigated. The prognostic value of all miRNAs was analyzed by multivariate Cox regression, and the miRNAs were ranked according to the hazard ratio (HR) and P-values. The top 5 miRNAs (miR-1301, miR-125a, miR-376c, miR-328 and miR-376b) were significantly associated with OS (HR=0.139; 95% confidence interval, 0.043–0.443; P<0.001), thus demonstrating that this panel was able to serve as an independent prognostic factor for PAAD. In addition, the present study also predicted the target genes of the top 10 miRNAs with the highest prognostic values using 12 different prediction software, and enrichment signaling pathway analyses elucidated that several pathways may be markedly associated with these miRNAs, including ‘Pathways in cancer’, ‘Chronic myeloid leukemia’, ‘Glioma’ and ‘MicroRNAs in cancer’. Lastly, ubiquitin C, epidermal growth factor receptor, estrogen receptor 1, mitogen-activated protein kinase 1, mothers against decapentaplegic homolog 4 and androgen receptor may be the hub genes revealed by STRING analysis. The present study identified several miRNAs, particularly a five-miRNA-pool, that may be reliable, independent factors for predicting survival in patients with PAAD. However, the underlying molecular mechanisms require further investigation in the future.

Role of miR-27a, miR-181a and miR-20b in gastric cancer hypoxia-induced chemoresistance

Despite the search for new therapeutic strategies for gastric cancer (GC), there is much evidence of progression due to resistance to chemotherapy. Multidrug resistance (MDR) is the ability of cancer cells to survive after exposure to chemotherapeutic agents. The involvement of miRNAs in the development of MDR has been well described but miRNAs able to modulate the sensitivity to chemotherapy by regulating hypoxia signaling pathways have not yet been fully addressed in GC. Our aim was to analyze miR-20b, miR-27a and miR-181a expression with respect to (epirubicin/oxaliplatin/capecitabine (EOX)) chemotherapy regimen in a set of GC patients, in order to investigate whether miRNAs deregulation may influence GC MDR also via hypoxia signaling modulation. Cancer biopsy were obtained from 21 untreated HER2 negative advanced GC patients, retrospectively analyzed. All patients received a first-line chemotherapy (EOX) regimen. MirWalk database was used to identify miR-27a, miR-181a and miR-20b target genes. The expression of miRNAs and of HIPK2, HIF1A and MDR1 genes were detected by real-time PCR. HIPK2 localization was assessed by immunohistochemistry. Our data showed the down-regulation of miR-20b, miR-27a, miR-181a concomitantly to higher levels of MDR1, HIF1A and HIPK2 genes in GC patients with a progressive disease respect to those with a disease control rate. Moreover, immunohistochemistry assay highlighted a higher cytoplasmic HIPK2 staining, suggesting a different role for it. We showed that aberrant expression of miR-20b, miR27a and miR-181a was associated with chemotherapeutic response in GC through HIF1A, MDR1 and HIPK2 genes modulation, suggesting a possible novel therapeutic strategy.

Angiogenesis in adenosquamous cancer of pancreas

Adenosquamous carcinoma of the pancreas (ASCP) is an uncommon variant of exocrine pancreatic malignancies, characterized by a histological admixture of adenomatous and squamous cell elements. This cancer is characterized by a poorly differentiated histology and a poorer clinical outcome compared to pancreatic ductal adenocarcinoma (PDAC). Unlike PDAC, that is characterized by a low microvascular density (MVD) and collapsed vasculature, no data are available about angiogenesis in ASPC. Immunohistochemical evaluation of MVD and trypatse-positive mast cells (MCs) were performed on a single case of ASCP compared to PDAC. Moreover, the levels of angiopoietin-1 and -2 (Ang-1, Ang-2), receptor tyrosine kinase with immunoglobulin and epidermal growth factor homology domain-2 (Tie-2), vascular endothelial growth factor A (VEGFA), hypoxia-inducible factor 1 alpha (HIF1A), miR-21-5p, miR-181a-5p, miR-122-5p, and miR-27a-3p were evaluated by real-time PCR. Higher number of tryptase-positive MCs and MVD are observed in the ASCP case compared to PDAC one. Lower levels of miR-122-5p and higher expression of VEGFA, HIF1A and Ang-2 genes were observed in ASCP. Furthermore, lower Ang-1 and Tie-2 transcript levels and higher increases of miR-21-5p, miR27a-3p and miR-181a-5p levels were found in the rarest form of pancreatic carcinoma. Our data demonstrate an important angiogenic activity in ASCP with a putative role of miR-21-5p, miR-181a-5p, miR-122-5p and miR-27a-3p in the regulation of this process.

Plasma microRNAs as biomarkers of pancreatic cancer risk in a prospective cohort study

Noninvasive biomarkers for early pancreatic ductal adenocarcinoma (PDAC) diagnosis and disease risk stratification are greatly needed. We conducted a nested case-control study within the Prospective Investigation into Cancer and Nutrition (EPIC) cohort to evaluate prediagnostic microRNAs (miRs) as biomarkers of subsequent PDAC risk. A panel of eight miRs (miR-10a, -10b, -21-3p, -21-5p, -30c, -106b, -155 and -212) based on previous evidence from our group was evaluated in 225 microscopically confirmed PDAC cases and 225 controls matched on center, sex, fasting status and age/date/time of blood collection. MiR levels in prediagnostic plasma samples were determined by quantitative RT-PCR. Logistic regression was used to model levels and PDAC risk, adjusting for covariates and to estimate area under the receiver operating characteristic curves (AUC). Plasma miR-10b, -21-5p, -30c and -106b levels were significantly higher in cases diagnosed within 2 years of blood collection compared to matched controls (all p-values <0.04). Based on adjusted logistic regression models, levels for six miRs (miR-10a, -10b, -21-5p, -30c, -155 and -212) overall, and for four miRs (-10a, -10b, -21-5p and -30c) at shorter follow-up time between blood collection and diagnosis (≤5 yr, ≤2 yr), were statistically significantly associated with risk. A score based on the panel showed a linear dose-response trend with risk (p-value = 0.0006). For shorter follow-up (≤5 yr), AUC for the score was 0.73, and for individual miRs ranged from 0.73 (miR-212) to 0.79 (miR-21-5p).

MicroRNA-216b-5p Functions as a Tumor-suppressive RNA by Targeting TPT1 in Pancreatic Cancer Cells

MicroRNAs (miRNAs) are increasingly recognized as being involved in pancreatic cancer progression by directly regulating the expression of their targets. In this study, we showed that miR-216b-5p expression was significantly decreased in pancreatic cancer tissues and cell lines. In addition, low miR-216b-5p expression was significantly associated with large tumor size and advanced TNM stage. Meanwhile, both Kaplan-Meier and multivariate survival analysis showed that decreased miR-216b-5p expression was associated with overall survival. miR-216b-5p over-expression repressed pancreatic cancer cell proliferation and induced cell cycle arrest and cell apoptosis in vitro and inhibited tumorigenesis in vivo. The translationally controlled tumor protein (TPT1) was identified as a novel direct target of miR-216b-5p. miR-216b-5p up-regulation suppressed TPT1 expression. Moreover, TPT1 mRNA expression levels were increased in pancreatic cancer tissues, and were inversely correlated with miR-216b-5p expression. TPT1 down-regulation had similar effects as miR-216b-5p up-regulation on pancreatic cancer cell progression. The restoration of TPT1 reversed the effect of miR-216b-5p on pancreatic cancer cell progression. Furthermore, we found that miR-216b-5p up-regulation suppressed Pim-3, Cyclin B1, p-Bad and Bcl-xL protein expression. However, the effect of miR-216b-5p up-regulation was partly reversed by TPT1 up-regulation in vitro. Taken together, our findings suggested that miR-216b-5p functions as a potential tumor suppressor by regulating TPT1 in pancreatic cancer cells, and it may represent a potential therapeutic target for patients with pancreatic cancer.

The pancreatic tumor microenvironment drives changes in miRNA expression that promote cytokine production and inhibit migration by the tumor associated stroma

The pancreatic adenocarcinoma (PDAC) microenvironment is largely comprised of fibrotic tumor associated stroma (TAS) that contributes to the lethal biology of PDAC. microRNA (miRNA) are small non-coding RNAs that regulate gene expression. We hypothesized that interactions between PDAC cells and TAS cells within the microenvironment modulate miRNA expression and thus, tumor biology. We observed that miR-205 and members of the miR-200 family (miR-200a, -200b, -200c, -141 and miR-429) were exclusively expressed in PDAC cells, consistent with an epithelial miRNA signature, while miR-145 and miR-199 family members (miR-199a and -199b) were solely expressed in TAS cells, consistent with a stromal miRNA signature. This finding was confirmed by qRT-PCR of RNA obtained by laser-capture microdissection of surgical specimens. Using an in vitro co-culture model, we further demonstrated regulation of miRNA expression by cell-cell contact. Forced expression in TAS cells of miR-200b/-200c and miR-205 to mimic these observed changes in miRNA concentrations induced secretion of GM-CSF and IP10, and notably inhibited migration. These data suggest interactions within the tumor microenvironment alter miRNA expression, which in turn have a functional impact on TAS.

The density of mast cells c-Kit+ and tryptase+ correlates with each other and with angiogenesis in pancreatic cancer patients

Literature data suggest that inflammatory cells such as mast cells (MCs) are involved in angiogenesis. MCs can stimulate angiogenesis by releasing of well identified pro-angiogenic cytokines stored in their cytoplasm. In particular, MCs can release tryptase, a potent in vivo and in vitro pro-angiogenic factor. Nevertheless, few data are available concerning the role of MCs positive to tryptase in primary pancreatic cancer angiogenesis. This study analyzed the correlation between mast cells positive to c-Kit receptor (c-Kit⁺ MCs), the density of MCs expressing tryptase (MCD-T) and microvascular density (MVD) in primary tumor tissue from patients affected by pancreatic ductal adenocarcinoma (PDAC). A series of 35 PDAC patients with stage T_2-3N_0-1M₀ (by AJCC for Pancreas Cancer Staging 7^th Edition) were selected and then undergone to surgery. Tumor tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of number of c-Kit⁺ MCs, MCD-T and MVD. The above parameters were related each other and with the most important main clinico-pathological features. A significant correlation between c-Kit⁺ MCs, MCD-T and MVD groups each other was found by Pearson t-test analysis (r ranged from 0.75 to 0.87; p-value ranged from 0.01 to 0.04). No other significant correlation was found. Our in vivo preliminary data, suggest that tumor microenvironmental MCs evaluated in terms of c-Kit⁺ MCs and MCD-T may play a role in PDAC angiogenesis and they could be further evaluated as a novel tumor biomarker and as a target of anti-angiogenic therapy.

Norcantharidin induces mitochondrial-dependent apoptosis through Mcl-1 inhibition in human prostate cancer cells

Norcantharidin (NCTD) is the demethylated form of cantharidin that exhibits anticancer potential in many cancer cell types. Recent reports suggest that NCTD targeting ROS/AMPK and DNA replication signaling pathway could be an effective strategy for the treatment of PCa cells. However, supportive evidence is limited to the effect of NCTD that induction of apoptosis through suppression of the Mcl-1. Here, we show that NCTD induced PCa cell apoptosis and triggered caspase activation, which was associated with mitochondria dysfunction. Mechanistic investigations suggested that NCTD modulated the Akt signaling via increased nuclear translocation and interaction with the myeloid cell leukemia-1 (Mcl-1) promoter by FOXO4, resulting in an apoptotic effect. Moreover, miR-320d, which targets Mcl-1, was significantly upregulated after NCTD treatment. Overexpression of miR-320d by NCTD induced mitochondria dysfunction and apoptosis, which was notably attenuated with a miR-320d inhibitor. In vivo xenograft analysis revealed that NCTD significantly reduced tumor growth in mice with PC3 tumor xenografts. Taken together, our results provide new insights into the critical role of NCTD in suppressing Mcl-1 via epigenetic upregulation of miR-320d, resulting in PCa cell apoptosis.

The microRNA expression signature of pancreatic ductal adenocarcinoma by RNA sequencing: anti-tumour functions of the microRNA-216 cluster

We analysed the RNA sequence-based microRNA (miRNA) signature of pancreatic ductal adenocarcinoma (PDAC). Aberrantly expressed miRNAs were successfully identified in this signature. Using the PDAC signature, we focused on 4 clustered miRNAs, miR-216a-5p, miR-216a-3p, miR-216b-5p and miR-216b-3p on human chromosome 2p16.1. All members of the miR-216 cluster were significantly reduced in PDAC specimens. Ectopic expression of these miRNAs suppressed cancer cell aggressiveness, suggesting miR-216 cluster as anti-tumour miRNAs in PDAC cells. The impact of miR-216b-3p (passenger strand of pre-miR-216b) on cancer cells is still ambiguous. Forkhead box Q1 (FOXQ1) was directly regulated by miR-216b-3p and overexpression of FOXQ1 was confirmed in clinical specimens. High expression of FOXQ1 predicted a shorter survival of patients with PDAC by Kaplan–Meier analysis. Loss-of-function assays showed that cancer cell migration and invasion activities were significantly reduced by siFOXQ1 transfectants. We investigated pathways downstream from FOXQ1 by using genome-wide gene expression analysis. Identification of the miR-216-3p/FOXQ1-mediated network in PDAC should enhance understanding of PDAC aggressiveness at the molecular level.

A comprehensive insight into the clinicopathologic significance of miR-144-3p in hepatocellular carcinoma

BACKGROUND

Studies which focused on the character of miR-144-3p in hepatocellular carcinoma (HCC) are limited. This study aimed to explore the expression, clinical significance and the potential targets of miR-144-3p in HCC.

METHODS

The Cancer Genome Atlas (TCGA) and a cohort of 95 cases of HCC were applied to investigate aberrant miR-144-3p expression in HCC. A meta-analysis was performed to accumulate data on miR-144-3p expression in HCC based on TCGA, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Gene Expression Omnibus (GEO). Additionally, the potential regulatory mechanisms of miR-144-3p in HCC were explored by bioinformatics.

RESULTS

MiR-144-3p expression was downregulated distinctly in HCC compared to para-HCC tissue both in TCGA data (8.9139±1.5986 vs 10.7721±0.9156, P<0.001) and in our qRT-PCR validation (1.3208±0.7594 vs 2.6200±0.9263, P<0.001). The meta-analysis based on TCGA, qRT-PCR and GEO data confirmed a consistent result (standard mean difference =-0.854, 95% CI: -1.224 to -0.484, P<0.001). The receiver operating characteristic curve of miR-144-3p gained a significant diagnostic value both in TCGA data (area under the curve [AUC] =0.852, 95% CI: 0.810 to 0.894, P<0.001) and in qRT-PCR validation (AUC =0.867, 95% CI: 0.817 to 0.916, P<0.001), especially in alpha-fetoprotein-negative HCC patients (AUC =0.900, 95% CI: 0.839 to 0.960, P<0.001). Furthermore, we identified 119 potential targets of miR-144-3p in HCC by bioinformatics. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that several significant biologic functions and pathways correlated with the pathogenesis of HCC, including the p53 signaling pathway.

CONCLUSION

MiR-144-3p may function as a cancer suppressor microRNA, which is essential for HCC progression through the regulation of various signaling pathways. Thus, interactions with miR-144-3p may provide a novel treatment strategy for HCC in the future.

Cell-free circulating DNA integrity is an independent predictor of impending breast cancer recurrence

Non-invasive blood-based molecule markers are evaluated as promising biomarkers these days. Here we investigated the potential of cell-free circulating DNA Integrity (cfDI) as blood-based marker for the prediction of recurrence during the follow-up of breast cancer patients within a prospective study cohort. cfDI was determined in plasma of 212 individuals, by measuring ALU and LINE1 repetitive DNA elements using quantitative PCR. A significant decrease of cfDI in recurrent breast cancer patients was observed. The group of patients who had impending recurrence during the follow-up had significant lower cfDI compared to the group of non-recurrent patients (P < 0.001 for ALU and LINE1 cfDI). cfDI could differentiate recurrent breast cancer patients from non-recurrent breast cancer subjects (area under the curve, AUC = 0.710 for ALU and 0.704 for LINE1). Univariate and multivariate analysis confirmed a significant association of recurrence and cfDI. Breast cancer patients with a lower cfDI had a much higher risk to develop recurrence than the patients with a higher cfDI (P = 0.020 for ALU cfDI and P = 0.019 for LINE1 cfDI, respectively). Further we show that cfDI is an independent predictor of breast cancer recurrence. In combination with other molecular markers, cfDI might be a useful biomarker for the prediction for breast cancer recurrence in clinic utility. We propose that cfDI might also be useful for the prediction of recurrence during the follow-up of other cancers.

Multimodal treatment of resectable pancreatic ductal adenocarcinoma

After a timing preoperative staging, treatment of resectable pancreatic adenocarcinoma (PDAC) includes surgery and adjuvant therapies, the former representing the initial therapeutic option and the latter aiming to reduce the incidence of both distant metastases (chemotherapy) and locoregional failures (chemoradiotherapy). Herein, we provide a critical overview on the role of multimodal treatment in PDAC and on new opportunities related to current more active poli-chemotherapy regimens, targeted therapies, and the more recent immunotherapy approaches. Moreover, an analysis of pathological markers and clinical features able to help clinicians in the selection of the best therapeutic strategy will be discussed. Lastly, the role of neoadjuvant treatment of initially resectable disease will be considered mostly in patients whose malignancy shows morphological but not clinical or biological criteria of resectability. Depending on the results of these investigational studies, today a multidisciplinary approach can offer the best address therapy for these patients.

The cornerstone K-RAS mutation in pancreatic adenocarcinoma: From cell signaling network, target genes, biological processes to therapeutic targeting

RAS belongs to the super family of small G proteins and plays crucial roles in signal transduction from membrane receptors in the cell. Mutations of K-RAS oncogene lead to an accumulation of GTP-bound proteins that maintains an active conformation. In the pancreatic ductal adenocarcinoma (PDAC), one of the most deadly cancers in occidental countries, mutations of the K-RAS oncogene are nearly systematic (>90%). Moreover, K-RAS mutation is the earliest genetic alteration occurring during pancreatic carcinogenetic sequence. In this review, we discuss the central role of K-RAS mutations and their tremendous diversity of biological properties by the interconnected regulation of signaling pathways (MAPKs, NF-κB, PI3K, Ral…). In pancreatic ductal adenocarcinoma, transcriptome analysis and preclinical animal models showed that K-RAS mutation alters biological behavior of PDAC cells (promoting proliferation, migration and invasion, evading growth suppressors, regulating mucin pattern, and miRNA expression). K-RAS also impacts tumor microenvironment and PDAC metabolism reprogramming. Finally we discuss therapeutic targeting strategies of K-RAS that have been developed without significant clinical success so far. As K-RAS is considered as the undruggable target, targeting its multiple effectors and target genes should be considered as potential alternatives.

Role of precision medicine in pancreatic cancer

Pancreatic cancer is one of the most challenging problems in modern oncology. Due to difficultly in early diagnosis and early distant metastasis of pancreatic cancer, surgical resection rate is less than 20% and patients' prognosis is very poor. Despite long-term efforts taken to develop treatments for pancreatic cancer, the survival rate did not significantly improve. Therefore, early diagnosis and treatment are the key to improve the survival rate of patients with pancreatic cancer. The advent of big-data genomic era and the rapid development of biotechnology have led to the recent proposal of a new concept of precise medicine, which has quickly become the focus of world medical conferences. Here, we describe the new progress and challenges of precision medicine in pancreatic cancer, with an aim to provide new ideas for improving the survival rate of patients with pancreatic cancer.

MiRNA-145 increases therapeutic sensibility to gemcitabine treatment of pancreatic adenocarcinoma cells

Pancreatic adenocarcinoma is one of the most leading causes of cancer-related deaths worldwide. Although recent advances provide various treatment options, pancreatic adenocarcinoma has poor prognosis due to its late diagnosis and ineffective therapeutic multimodality. Gemcitabine is the effective first-line drug in pancreatic adenocarcinoma treatment. However, gemcitabine chemoresistance of pancreatic adenocarcinoma cells has been a major obstacle for limiting its treatment effect. Our study found that p70S6K1 plays an important role in gemcitabine chemoresistence. MiR-145 is a tumor suppressor which directly targets p70S6K1 for inhibiting its expression in pancreatic adenocarcinoma, providing new therapeutic scheme. Our findings revealed a new mechanism underlying gemcitabine chemoresistance in pancreatic adenocarcinoma cells.

Advance in microRNA as a potential biomarker for early detection of pancreatic cancer

Pancreatic cancer is characterized as a disease with low survival and high mortality because of no effective diagnostic and therapeutic strategies available in clinic. Conventional clinical diagnostic methods including serum markers and radiological imaging (CT, MRI, EUS, etc.) often fail to detect precancerous or early stage lesions. Development of effective biomarkers is unmet for reduction of mortality of pancreatic cancer. MicroRNAs (miRNAs) are a group of small non-protein-coding RNAs playing roles in regulation of cell physiology including tumorigenesis, apoptotic escape, proliferation, invasion, epithelial-mesenchymal transition (EMT), metastasis and chemoresistance. Various altered signaling pathways involving in molecular pathogenesis of pancreatic cancer are mediated by miRNAs as a role of either oncogenes or tumor suppressors. Among biomarkers developed including protein, metabolites, DNA, RNA, epigenetic mutation, miRNAs are superior because of its unique chemical property. Recent study suggests that miRNAs may be promising biomarkers used for early detection of pancreatic cancer. This review will update the progression made in early detection of pancreatic cancer.

Angiogenesis in pancreatic ductal adenocarcinoma: A controversial issue

Pancreatic ductal adenocarcinoma (PDAC) occurs in the majority of cases with early loco-regional spread and distant metastases at diagnosis, leading to dismal prognosis with a 5-year overall survival rate moderately over than 5%. This malignancy is largely resistant to chemotherapy and radiation, but the reasons of the refractoriness to the therapies is still unknown. Evidence is accumulating to indicate that the PDAC microenvironment and vascularity strongly contribute to the clinical features of this disease. In particular, PDAC is characterized by excessive dense extracellular matrix deposition associated to vasculature collapse and hypoxia with low drug delivery, explaining at least partly the low efficacy of antiangiogenic drugs in this cancer. Strategies aimed to modulate tumor stroma favoring vasculature perfusion and chemotherapeutics delivery are under investigation.