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

PGCNMDA: Learning node representations along paths with graph convolutional network for predicting miRNA-disease associations

Identifying miRNA-disease associations (MDAs) is crucial for improving the diagnosis and treatment of various diseases. However, biological experiments can be time-consuming and expensive. To overcome these challenges, computational approaches have been developed, with Graph Convolutional Network (GCN) showing promising results in MDA prediction. The success of GCN-based methods relies on learning a meaningful spatial operator to extract effective node feature representations. To enhance the inference of MDAs, we propose a novel method called PGCNMDA, which employs graph convolutional networks with a learning graph spatial operator from paths. This approach enables the generation of meaningful spatial convolutions from paths in GCN, leading to improved prediction performance. On HMDD v2.0, PGCNMDA obtains a mean AUC of 0.9229 and an AUPRC of 0.9206 under 5-fold cross-validation (5-CV), and a mean AUC of 0.9235 and an AUPRC of 0.9212 under 10-fold cross-validation (10-CV), respectively. Additionally, the AUC of PGCNMDA also reaches 0.9238 under global leave-one-out cross-validation (GLOOCV). On HMDD v3.2, PGCNMDA obtains a mean AUC of 0.9413 and an AUPRC of 0.9417 under 5-CV, and a mean AUC of 0.9419 and an AUPRC of 0.9425 under 10-CV, respectively. Furthermore, the AUC of PGCNMDA also reaches 0.9415 under GLOOCV. The results show that PGCNMDA is superior to other compared methods. In addition, the case studies on pancreatic neoplasms, thyroid neoplasms and leukemia show that 50, 50 and 48 of the top 50 predicted miRNAs linked to these diseases are confirmed, respectively. It further validates the effectiveness and feasibility of PGCNMDA in practical applications.

Extracellular Vesicular miRNA in Pancreatic Cancer: From Lab to Therapy

Pancreatic cancer is a prevalent lethal gastrointestinal cancer that generally does not show any symptoms until it reaches advanced stages, resulting in a high mortality rate. People at high risk, such as those with a family history or chronic pancreatitis, do not have a universally accepted screening protocol. Chemotherapy and radiotherapy demonstrate limited effectiveness in the management of pancreatic cancer, emphasizing the urgent need for innovative therapeutic strategies. Recent studies indicated that the complex interaction among pancreatic cancer cells within the dynamic microenvironment, comprising the extracellular matrix, cancer-associated cells, and diverse immune cells, intricately regulates the biological characteristics of the disease. Additionally, mounting evidence suggests that EVs play a crucial role as mediators in intercellular communication by the transportation of different biomolecules, such as miRNA, proteins, DNA, mRNA, and lipids, between heterogeneous cell subpopulations. This communication mediated by EVs significantly impacts multiple aspects of pancreatic cancer pathogenesis, including proliferation, angiogenesis, metastasis, and resistance to therapy. In this review, we delve into the pivotal role of EV-associated miRNAs in the progression, metastasis, and development of drug resistance in pancreatic cancer as well as their therapeutic potential as biomarkers and drug-delivery mechanisms for the management of pancreatic cancer.

Circulating miRNAs as Noninvasive Biomarkers for PDAC Diagnosis and Prognosis in Mexico

Among malignant neoplasms, pancreatic ductal adenocarcinoma (PDAC) has one of the highest fatality rates due to its late detection. Therefore, it is essential to discover a noninvasive, early, specific, and sensitive diagnostic method. MicroRNAs (miRNAs) are attractive biomarkers because they are accessible, highly specific, and sensitive. It is crucial to find miRNAs that could be used as possible biomarkers because PDAC is the eighth most common cause of cancer death in Mexico. With the help of microRNA microarrays, differentially expressed miRNAs (DEmiRNAs) were found in PDAC tissues. The presence of these DEmiRNAs in the plasma of Mexican patients with PDAC was determined using RT-qPCR. Receiver operating characteristic curve analysis was performed to determine the diagnostic capacity of these DEmiRNAs. Gene Expression Omnibus datasets (GEO) were employed to verify our results. The Prisma V8 statistical analysis program was used. Four DEmiRNAs in plasma from PDAC patients and microarray tissues were found. Serum samples from patients with PDAC were used to validate their overexpression in GEO databases. We discovered a new panel of the two miRNAs miR-222-3p and miR-221-3p that could be used to diagnose PDAC, and when miR-221-3p and miR-222-3p were overexpressed, survival rates decreased. Therefore, miR-222-3p and miR-221-3p might be employed as noninvasive indicators for the diagnosis and survival of PDAC in Mexican patients.

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.

Diagnostic utility of quantitative analysis of microRNA in bile samples obtained during endoscopic retrograde cholangiopancreatography for malignant biliary strictures

BACKGROUND

The sensitivity of bile cytology for malignant biliary strictures is not adequate. To overcome this limitation, we evaluated whether quantitative analysis of microRNAs (miRNAs) in bile can provide a precise diagnosis of malignant biliary strictures due to pancreatic cancer (PC) and biliary tract cancer (BTC).

METHODS

This was a retrospective evaluation of miRNA levels in stored bile samples of patients with PC, BTC or benign biliary stricture obtained during biliary drainage from April 2019 to December 2021 at our institution. A total of 113 patients (PC; n = 40, BTC; n = 38, control; n = 35) were enrolled. The miRNA candidates to be quantified were determined with microarray analysis from each 3 patients with PC, BTC and controls.

RESULTS

Using microarray analysis, we confirmed four significantly up-regulated miRNAs (miR-1275, miR-6891-5p, miR-7107-5p, miR-3197) in patients with PC and BTC compared to control patients. Quantitative PCR was then performed in 113 bile samples for these miRNAs. miR-1275 was significantly upregulated in PC (p = 0.003) and BTC (p = 0.049) compared to controls, miR-6891-5p was significantly upregulated in PC compared to controls (p = 0.025). In particular, a combination of bile cytology and miR-1275 in bile showed a sensitivity of 77.5% (95% CI, 70.7-77.5%), specificity of 100% (95% CI, 92.2-100%) and an area under the curve (AUC) of 0.93, and provided a significantly greater additional diagnostic effect than bile cytology alone (p = 0.014).

CONCLUSIONS

This study suggest that bile miRNAs could be potential biomarkers for pancreato-biliary diseases, particularly miR-1275 and miR-6891-5p may be helpful in the diagnosis of PC and BTC.

Amplification-Free, High-Throughput Nanoplasmonic Quantification of Circulating MicroRNAs in Unprocessed Plasma Microsamples for Earlier Pancreatic Cancer Detection

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy that is often detected at an advanced stage. Earlier diagnosis of PDAC is key to reducing mortality. Circulating biomarkers such as microRNAs are gaining interest, but existing technologies require large sample volumes, amplification steps, extensive biofluid processing, lack sensitivity, and are low-throughput. Here, we present an advanced nanoplasmonic sensor for the highly sensitive, amplification-free detection and quantification of microRNAs (microRNA-10b, microRNA-let7a) from unprocessed plasma microsamples. The sensor construct utilizes uniquely designed -ssDNA receptors attached to gold triangular nanoprisms, which display unique localized surface plasmon resonance (LSPR) properties, in a multiwell plate format. The formation of -ssDNA/microRNA duplex controls the nanostructure-biomolecule interfacial electronic interactions to promote the charge transfer/exciton delocalization processes and enhance the LSPR responses to achieve attomolar (10^-18 M) limit of detection (LOD) in human plasma. This improve LOD allows the fabrication of a high-throughput assay in a 384-well plate format. The performance of nanoplasmonic sensors for microRNA detection was further assessed by comparing with the qRT-PCR assay of 15 PDAC patient plasma samples that shows a positive correlation between these two assays with the Pearson correlation coefficient value >0.86. Evaluation of >170 clinical samples reveals that oncogenic microRNA-10b and tumor suppressor microRNA-let7a levels can individually differentiate PDAC from chronic pancreatitis and normal controls with >94% sensitivity and >94% specificity at a 95% confidence interval (CI). Furthermore, combining both oncogenic and tumor suppressor microRNA levels significantly improves differentiation of PDAC stages I and II versus III and IV with >91% and 87% sensitivity and specificity, respectively, in comparison to the sensitivity and specificity values for individual microRNAs. Moreover, we show that the level of microRNAs varies substantially in pre- and post-surgery PDAC patients (n = 75). Taken together, this ultrasensitive nanoplasmonic sensor with excellent sensitivity and specificity is capable of assaying multiple biomarkers simultaneously and may facilitate early detection of PDAC to improve patient care.

Clinical Value of Circulating miRNA in Diagnosis, Prognosis, Screening and Monitoring Therapy of Pancreatic Ductal Adenocarcinoma-A Review of the Literature

Pancreatic cancer (PC) is considered to be the seventh most common cause of cancer-related deaths. The number of deaths caused by PC is estimated to increase in the future. An early diagnosis of PC is crucial for improving treatment outcomes. The most common histopathological subtype of PC is pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miRNAs)-which are endogenous non-coding RNAs involved in the posttranscriptional regulation of multiple gene expression-constitute useful diagnostic and prognostic biomarkers in various neoplasms, including PDAC. Circulating miRNAs detected in a patient's serum or plasma are drawing more and more attention. Hence, this review aims at evaluating the clinical value of circulating miRNA in the screening, diagnosis, prognosis and monitoring of pancreatic ductal adenocarcinoma therapy.

Cu2+@NMOFs-to-bimetallic CuFe PBA transformation: An instant catalyst with oxidase-mimicking activity for highly sensitive impedimetric biosensor

In this work, a facile impedance biosensor was constructed for sensitive assaying of miRNA-10b based on the Cu²⁺ modified NH₂-metal organic frameworks (NMOF@Cu²⁺) coupling with a three-dimensional (3D) DNA walker signal amplification strategy. Specifically, abundant Cu²⁺ can adhere to the MOF via the coordination reaction between NH₂ and Cu²⁺, which can be applied as a skeleton to produce CuFe Prussian blue analogue@NMOF (CuFe PBA@NMOF) just in time. Meanwhile, the carboxyl group, which is rich in the organic ligands of the NMOF, can be used to assemble DNA strands (complementary strand, CS) (CS-NMOF@Cu²⁺) for biorecognition reaction. With the introduction of the target, a 3D DNA walker was triggered to shear out large amounts of assistant strands (AS), which were then anchored on the surface of GCE. Afterward, CS-NMOF@Cu²⁺ can be assembled on the GCE by hybridization with AS. Eventually, abundant CuFe PBA@NMOF were generated in situ on the electrode with the help of K₃[Fe(CN)₆], which can catalyze the 4-chloro-1-naphthol (4-CN) precipitation without H₂O₂, thereby increasing the resistance of the platform. Under the optimal conditions, the EIS biosensor presents reliable analytical performance in a wide linear range from 0.8 pM to 250 pM with a low detection limit of 0.5 pM.

Selecting optimum miRNA panel for miRNA signature-based companion diagnostic model to predict the response of R-CHOP treatment in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma. Although the first-line treatment, R-CHOP treatment, shows efficacy in approximately 80% of patients with DLBCL, some patients have refractory disease or relapse after the initial response to therapy, resulting in a significantly poorer prognosis. In this study, we developed a microRNA (miRNA) signature-based companion diagnostic model to predict the response of patients with DLBCL to R-CHOP treatment by integrating two clinical study datasets. To select the optimum miRNA combination as a panel, we examined three feature selection methods (p-value-based ranking, stepwise method, and Boruta), together with 11 types of classifiers systematically. Boruta selection enabled a higher area under the curve (AUC) with a lower number of miRNAs compared with other feature selection methods, leading to an AUC of 0.751 via the random forest classifier using 36 miRNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that Boruta avoided multiple selection of miRNAs with similar functions, thereby preventing the decrease in diagnostic ability via collinearity. The AUC value first increased with an increasing number of miRNAs and then became almost constant at approximately 30 miRNAs, suggesting the existence of the optimum number of miRNAs as a panel for future clinical translation of multiple miRNA-based diagnostics.

Liquid biopsy leads to a paradigm shift in the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most cancers. Its 5-year survival rate is very low. The recent induction of neoadjuvant chemotherapy and improvements in chemotherapy for patients with pancreatic cancer have resulted in improved survival outcomes. However, the prognosis of pancreatic cancer is still poor. To dramatically improve the prognosis, we need to develop more tools for early diagnosis, treatment selection, disease monitoring, and response rate evaluation. Recently, liquid biopsy (circulating free DNA, circulating tumor DNA, circulating tumor cells, exosomes, and microRNAs) has caught the attention of many researchers as a new biomarker that is minimally invasive, confers low-risk, and displays an overall state of the tumor. Thus, liquid biopsy does not employ the traditional difficulties of obtaining tumor samples from patients with advanced PDAC to investigate their molecular biological status. In addition, it allows for long-term monitoring of the molecular profile of tumor progression. These could help in identifying tumor-specific alterations that use the target structure for tailor-made therapy. Through this review, we highlighted the latest discoveries and advances in liquid biopsy technology in pancreatic cancer research and showed how it can be applied in clinical practice.

Diagnosis of Pancreatic Cancer Using miRNA30e Biosensor

This work describes miRNA-based electrochemical biosensor for detection of miRNA30e, a pancreatic cancer biomarker. The screen-printed gold electrode was functionalized using cysteine hydrochloride followed by immobilization of synthesized colloidal gold nanorods (10-12 nm diameter and 25-65 nm length). The gold nanorods modified electrode surface was amino functionalized for covalent attachment of single-stranded DNA probe against miRNA30e (miR30e). This platform was utilized for electrochemical measurements and response analysis of target miRNA30e. Electrochemical impedance spectroscopic measurements showed very poor sensitivity (13.51 Ω/µg/mL/cm²) using charge transfer resistance calibration plots. Cyclic voltammetry and differential pulse voltammetry-based miR30e quantification showed decreasing current response with increasing concentration of miR30e with detection range of 0.1 fg/mL-0.1 µg/mL (14.9 aM-14.9 nM). The sensitivity of DPV sensing (104.4 µA/µg/mL/cm²) was found to be 1.3 times higher than that of CV-based quantification (79.6 µA/µg/mL/cm²). miRNA-based biosensors have the potential of replacing current invasive, time consuming and technically difficult diagnostic procedures. Furthermore, the lower limit of detection of 14.9 aM miRNA30e makes it a promising tool for detection of cancer at early stages and hence increasing survival rate.

Pathological and molecular diagnoses of early cancer with bile and pancreatic juice

The dismal prognosis of pancreaticobiliary malignancies is mainly attributed to the extremely difficult detection of early-stage lesions, including intraepithelial neoplasia. To improve prognosis, several studies on the early detection of cancer have been conducted using bile and pancreatic juices for pathological or molecular analyses. One approach is liquid biopsy that includes information about the tumor, such as circulating tumor cells, circulating tumor DNA, microRNAs, and exosomes released by the tumor. Another approach is proteomics/metabolomics that reflects specific conditions in the tumor. These two approaches lead to artificial intelligence-based multiomics analyses that comprises genomics, proteomics/metabolomics, and transcriptomics. Based on the findings of molecular analysis, pathological analysis using immunohistochemical staining/fluorescence in situ hybridization has also been developed. Moreover, there have been reports of new methods/ingenuities for obtaining appropriate samples for the diagnosis of early-stage cancer. Here we review the knowledge on cutting-edge pathological and molecular analyses of bile and pancreatic juices, introduce some ingenuities in sampling and sample processing to promote effective clinical practice, and provide a basis for future studies.

RNA-sequencing for transcriptional profiling of whole blood in early stage and metastatic pancreatic cancer patients

We investigated the transcriptional profile of whole blood in early and metastatic stages of pancreatic cancer (PaC) patients to identify potential diagnostic factors for early diagnosis. Blood samples from 18 participants (6 healthy individuals, 6 patients in early stage (I/II) PaC, and 6 patients in metastatic PaC) were analyzed by RNA-sequencing. The expression levels of identified genes were subsequently compared with their expression in pancreatic tumor tissues based on TCGA data reported in UALCAN and GEPIA2 databases. Overall, 331 and 724 genes were identified as differentially expressed genes in early and metastatic stages, respectively. Of these, 146 genes were shared by early and metastatic stages. Upregulation of PTCD3 and UBA52 genes and downregulation of A2M and ARID1B genes in PaC patients were observed from early stage to metastasis. TCGA database showed increasing trend in expression levels of these genes from stage I to IV in pancreatic tumor tissue. Finally, we found that low expression of PTCD3, A2M, and ARID1B genes and high expression of UBA52 gene were positively correlated with PaC patients survival. We identified a four-gene set (PTCD3, UBA52, A2M, and ARID1B) expressed in peripheral blood of early stage and metastatic PaC patients that may be useful for PaC early diagnosis.

MicroRNAs as Indicators of Malignancy in Pancreatic Ductal Adenocarcinoma (PDAC) and Cystic Pancreatic Lesions

The dysregulation of microRNAs has recently been associated with cancer development and progression in pancreatic ductal adenocarcinoma (PDAC) and cystic pancreatic lesions. In solid pancreatic tumor tissue, the dysregulation of miR-146, miR-196a/b, miR-198, miR-217, miR-409, and miR-490, as well as miR-1290 has been investigated in tumor biopsies of patients with PDAC and was reported to predict cancer presence. However, the value of the predictive biomarkers may further be increased during clinical conditions suggesting cancer development such as hyperinsulinemia or onset of diabetes. In this specific context, the dysregulation of miR-486 and miR-196 in tumors has been observed in the tumor tissue of PDAC patients with newly diagnosed diabetes mellitus. Moreover, miR-1256 is dysregulated in pancreatic cancer, possibly due to the interaction with long non-coding RNA molecules that seem to affect cell-cycle control and diabetes manifestation in PDAC patients, and, thus, these three markers may be of special or “sentinel value”. In blood samples, Next-generation sequencing (NGS) has also identified a set of microRNAs (miR-20a, miR-31-5p, miR-24, miR-25, miR-99a, miR-185, and miR-191) that seem to differentiate patients with pancreatic cancer remarkably from healthy controls, but limited data exist in this context regarding the prediction of cancer presences and outcomes. In contrast to solid pancreatic tumors, in cystic pancreatic cancer lesions, as well as premalignant lesions (such as intraductal papillary neoplasia (IPMN) or mucinous-cystic adenomatous cysts (MCAC)), the dysregulation of a completely different expression panel of miR-31-5p, miR-483-5p, miR-99a-5p, and miR-375 has been found to be of high clinical value in differentiating benign from malignant lesions. Interestingly, signal transduction pathways associated with miR-dysregulation seem to be entirely different in patients with pancreatic cysts when compared to PDAC. Overall, the determination of these different dysregulation “panels” in solid tumors, pancreatic cysts, obtained via fine-needle aspirate biopsies and/or in blood samples at the onset or during the treatment of pancreatic diseases, seems to be a reasonable candidate approach for predicting cancer presence, cancer development, and even therapy responses.

Apigenin Targets MicroRNA-155, Enhances SHIP-1 Expression, and Augments Anti-Tumor Responses in Pancreatic Cancer

Pancreatic cancer (PC) is a deadly disease with a grim prognosis. Pancreatic tumor derived factors (TDF) contribute to the induction of an immunosuppressive tumor microenvironment (TME) that impedes the effectiveness of immunotherapy. PC-induced microRNA-155 (miRNA-155) represses expression of Src homology 2 (SH2) domain-containing Inositol 5'-phosphatase-1 (SHIP-1), a regulator of myeloid cell development and function, thus impacting anti-tumor immunity. We recently reported that the bioflavonoid apigenin (API) increased SHIP-1 expression which correlated with the expansion of tumoricidal macrophages (TAM) and improved anti-tumor immune responses in the TME of mice with PC. We now show that API transcriptionally regulates SHIP-1 expression via the suppression of miRNA-155, impacting anti-tumor immune responses in the bone marrow (BM) and TME of mice with PC. We discovered that API reduced miRNA-155 in the PC milieu, which induced SHIP-1 expression. This promoted the restoration of myelopoiesis and increased anti-tumor immune responses in the TME of heterotopic, orthotopic and transgenic SHIP-1 knockout preclinical mouse models of PC. Our results suggest that manipulating SHIP-1 through miR-155 may assist in augmenting anti-tumor immune responses and aid in the therapeutic intervention of PC.

The Role, Significance, and Association of MicroRNA-10a/b in Physiology of Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that regulate the translation of mRNA and protein, mainly at the posttranscriptional level. Global expression profiling of miRNAs has demonstrated a broad spectrum of aberrations that correlated with several diseases, and miRNA- 10a and miRNA-10b were the first examined miRNAs to be involved in abnormal activities upon dysregulation, including many types of cancers and progressive diseases. It is expected that the same miRNAs behave inconsistently within different types of cancer. This review aims to provide a set of information about our updated understanding of miRNA-10a and miRNA-10b and their clinical significance, molecular targets, current research gaps, and possible future applications of such potent regulators.

Comprehensive Evaluation and Application of a Novel Method to Isolate Cell-Free DNA Derived From Bile of Biliary Tract Cancer Patients

Cell-free DNA (cfDNA) exists in various types of bodily fluids, including plasma, urine, bile, and others. Bile cfDNA could serve as a promising liquid biopsy for biliary tract cancer (BTC) patients, as bile directly contacts tumors in the biliary tract system. However, there is no commercial kit or widely acknowledged method for bile cfDNA extraction. In this study, we established a silica-membrane-based method, namely 3D-BCF, for bile cfDNA isolation, exhibiting effective recovery of DNA fragments in the spike-in assay. We then compared the 3D-BCF method with four other commercial kits: the BIOG cfDNA Easy Kit (BIOG), QIAamp DNA Mini Kit (Qiagen), MagMAX^TM Cell-Free DNA Isolation Kit (Thermo Fisher), and NORGEN Urine Cell-Free Circulating DNA Purification Mini Kit (Norgen Biotek). The proposed 3D-BCF method exhibited the highest cfDNA isolation efficiency (p < 0.0001) from patient bile samples, and bile cfDNA of short, medium or long fragments could all be extracted effectively. To test whether the extracted bile cfDNA from patients carries tumor-related genomic information, we performed next-generation sequencing on the cfDNA and verified the gene-mutation results by polymerase chain reaction (PCR)-Sanger chromatograms and copy-number-variation (CNV) detection by fluorescence in situ hybridization (FISH) of tumor tissues. The 3D-BCF method could efficiently extract cfDNA from bile samples, providing technical support for bile cfDNA as a promising liquid biopsy for BTC patient diagnosis and prognosis.

Extracellular vesicle biomarkers for pancreatic cancer diagnosis: a systematic review and meta-analysis

BACKGROUND

Extracellular vesicle (EV) biomarkers have promising diagnosis and screening capacity for several cancers, but the diagnostic value for pancreatic cancer (PC) is controversial. The aim of our study was to review the diagnostic performance of EV biomarkers for PC.

METHODS

We performed a systematic review of PubMed, Medline, and Web Of Science databases from inception to 18 Feb 2022. We identified studies reporting the diagnostic performance of EV biomarkers for PC and summarized the information of sensitivity, specificity, area under the curve (AUC), or receiver operator characteristic (ROC) curve) in according to a pre-designed data collection form. Pooled sensitivity and specificity was calculated using a random-effect model.

RESULTS

We identified 39 studies, including 2037 PC patients and 1632 noncancerous, seven of which were conducted independent validation tests. Seventeen studies emphasized on EV RNAs, sixteen on EV proteins, and sixteen on biomarker panels. MiR-10b, miR-21, and GPC1 were the most frequently reported RNA and protein for PC diagnosis. For individual RNAs and proteins, the pooled sensitivity and specificity were 79% (95% CI: 77-81%) and 87% (95% CI: 85-89%), 72% (95% CI: 69-74%) and 77% (95% CI: 74-80%), respectively. the pooled sensitivity and specificity of EV RNA combined with protein panels were 84% (95% CI: 81-86%) and 89% (95% CI: 86-91%), respectively. Surprisingly, for early stage (stage I and II) PC EV biomarkers showed excellent diagnostic performance with the sensitivity of 90% (95% CI: 87-93%) and the specificity of 94% (95% CI: 92-95%). Both in sensitivity and subgroup analyses, we did not observe notable difference in pooled sensitivity and specificity. Studies might be limited by the isolation and detection techniques of EVs to a certain extent.

CONCLUSIONS

EV biomarkers showed appealing diagnostic preference for PC, especially for early stage PC. Solving the deficiency of technologies of isolation and detection EVs has important implications for application these novel noninvasive biomarkers in clinical practice.

Methylation of Tumor Suppressive miRNAs in Plasma from Patients With Pancreaticobiliary Diseases

BACKGROUND/AIM

We previously reported the usefulness of aberrant methylation of tumor suppressive miRNAs in bile to discriminate pancreaticobiliary cancers (PBCs) from benign pancreaticobiliary diseases (BD). Here we performed a methylation analysis of plasma miRNAs to identify miRNAs specific for PBCs.

PATIENTS AND METHODS

Plasma was collected from 80 patients with pancreatic cancer (PC); 18 with biliary tract cancer (BTC) and 28 with BD. Sequences encoding 3 tumor suppressive miRNAs (miR-200a, -200b, and -1247) were PCR amplified and sequenced, and their methylation rates were determined.

RESULTS

The methylation rate of miR-1247 was significantly higher in patients with BTC than in those with BD, and tended to be higher in patients with PC than in those with BD. Furthermore, it was significantly higher in three patients with stages I/II BTC than in those with BD.

CONCLUSION

Methylation of miR-1247 in plasma may be useful to distinguish BTC from BD.

MiR-212 value in prognosis and diagnosis of cancer and its association with patient characteristics: a systematic review and meta-analysis

Background

Delayed cancer diagnosis and inefficient cancer prognosis determination are problems faced in cancer diagnosis and treatment. MicroRNAs (miRs), especially miR-212, have shown a promise in cancer diagnosis and prognosis. Herein, we performed a systematic review and meta-analysis to assess the prognostic and diagnostic value of miR-212 level in cancer and evaluated its association with patient characteristics.

Methods

A fully electronic literature search using related keywords was performed in PubMed, Scopus, Web of Science, Embase, and ScienceDirect databases by June 6, 2021, with no time or language restriction. Meta-analysis was performed to pool survival prognosis data using hazard ratio (HR), association using odds ratio (OR), and diagnostic data using sensitivity, specificity, and diagnostic odds ratio (DOR). Sub-group analysis and meta-regression were performed as appropriate.

Results

Results of 28 studies on 1880 patients showed a poor cancer prognosis with high levels of miR-212 in pancreatic ductal adenocarcinoma (PDAC, HR = 2.451 [1.447–4.149]), and a poor cancer prognosis with low levels of miR-212 in other cancers (HR = 2.514 [2.162–2.923]). Higher alpha-fetoprotein (AFP) level and Edmondson-Steiner grade were factors associated with miR-212 low level incidence. Diagnostic odds ratio 10.688 (3.644–31.348) and SROC AUC of 0.84 confirmed high diagnostic performance of miR-212.

Conclusion

Our systematic review and meta-analysis results confirm miR-212 high value in cancer prognosis and diagnosis. High level of miR-212 showed poor prognosis in PDAC and low level of miR-212 showed poor prognosis in other cancers. in conclusion, miR-212 could be a novel potential biomarker in cancer diagnosis and prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02584-0.

Circulating miRNA and cell-free DNA as a potential diagnostic tool in early detection of biliary tract cancer: A meta-analysis

AIM

To investigate the clinical efficacy of miRNA, cell-free DNA, and circulating tumor cells in biliary tract cancer diagnosis.

METHODS

A comprehensive literature search was conducted up to September 2021, using public databases. The quality of the screened articles was evaluated using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS 2) tool followed by statistical analysis. Revman 5.4, Meta-disc 1.4, and MetaEssential were used for the statistical estimation.

RESULTS

A total of 28 studies were retrieved that involved 3,333 participants (1,874 patients and 1,450 control). Overall performance in terms of pooled sensitivity and specificity was 0.84 and 0.91 individually. Moreover, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and area under the curve (AUC) were 10.29, 0.15, and 0.9567 respectively. Subgroup analysis based on the sample source revealed that plasma can be a prominent source in diagnosing BTC. Publication bias assessed using Begg's and Egger's test reported that no publication bias was present (p-value: 0.083, 0.162).

CONCLUSIONS

The miRNA and cell-free DNA exhibited a high diagnostic value in early diagnosis. While CTCs might be useful in the later stages.

Analysis of MicroRNA in Bile Cytologic Samples Is Useful for Detection and Diagnosis of Extrahepatic Cholangiocarcinoma

OBJECTIVES

This study aimed to develop reliable biomarkers that improve the ability of bile cytology to diagnose cholangiocarcinoma vs benign biliary lesions.

METHODS

Many studies indicate that microRNAs (miRNAs) are potential candidates for the early diagnosis of cancer. We analyzed the expression of five tumor-associated miRNAs (miR-31-5p, miR-122-5p, miR-378d, miR-182-5p, and miR-92a-3p) in cytology samples using quantitative reverse transcription polymerase chain reaction. We collected 52 surgically resected tissue samples, 84 cytologic specimens from smears (53 cases of cancer and 31 cases of noncancer), and 40 residual sediments after smearing for routine cytology at Hiroshima University Hospital.

RESULTS

The expression of miR-31-5p, miR-378d, and miR-122-5p was significantly higher in cancer tissues than those in normal tissues, while miR-182-5p expression was lower. The expression of miR-31-5p, miR-378d, miR-182-5p, and miR-92a-3p was significantly higher in detached cell samples from smears of cholangiocarcinoma cases than in those from noncancer cases.

CONCLUSIONS

These results suggest that the analysis of miRNAs in bile cytologic specimens is a promising auxiliary tool for distinguishing cholangiocarcinoma from benign biliary lesions.

Rational Utilization of Photoelectrochemistry of Photosystem II for Self-Powered Photocathodic Detection of MicroRNA in Cells

The photoanode, photosystem II (PSII)/hierarchical inverse opal (IO) TiO₂, is coupled to the complementary photocathode, PbS quantum dots (QDs)/DNA probes, which is then integrated into a two-compartment photoelectrochemical (PEC) cell to achieve a self-powered system to enable photocathodic detection of microRNA-10b from HeLa cells. In such a system, all of the PSII catalytic products, i.e., electrons, protons, and O₂, were rationally utilized and could overcome the general issue of varied O₂ levels in photocathodic detection. The correlation between the target-triggered formation of the DNA complexes and the catalytic reduction of the dissolved O₂ makes possible the steady microRNA-10b detection with good sensitivity and selectivity. This work has unveiled the ability of PSII to construct self-powered detecting devices and shed light on its application in new arenas.

Isolation of extra-cellular vesicles in the context of pancreatic adenocarcinomas: Addition of one stringent filtration step improves recovery of specific microRNAs

microRNAs (miRNA) in extracellular vesicles (EVs) have been investigated as potential biomarkers for pancreatic ductal adenocarcinoma (PDAC). However, a mixed population of EVs is often obtained using conventional exosome isolation methods for biomarker development. EVs are derived from different cellular processes and present in various sizes, therefore miRNA expression among them is undoubtedly different. We developed a simple protocol utilizing sequential filtration and ultracentrifugation to separate PDAC EVs into three groups, one with an average diameter of more than 220 nm, named operational 3 (OP3); one with average diameters between 100-220 nm, named operational 2 (OP2); and another with average diameters around 100 nm, named operational 1 (OP1)). EVs were isolated from conditioned cell culture media and plasma of human PDAC xenograft mice and early stage PDAC patients, and verified by nanoparticle tracking, western blot, and electronic microscopy. We demonstrate that exosome specific markers are only enriched in the OP1 group. qRT-PCR analysis of miRNA expression in EVs from PDAC cells revealed that expression of miR-196a and miR-1246, two previously identified miRNAs highly enriched in PDAC cell-derived exosomes, is significantly elevated in the OP1 group relative to the other EV groups. This was confirmed using plasma EVs from PDAC xenograft mice and patients with localized PDAC. Our results indicate that OP1 can be utilized for the identification of circulating EV miRNA signatures as potential biomarkers for PDAC.

The Role of microRNA in Pancreatic Cancer

MicroRNAs (miRNAs) are small ribonucleic acid molecules that play a key role in regulating gene expression. The increasing number of studies undertaken on the functioning of microRNAs in the tumor formation clearly indicates their important potential in oncological therapy. Pancreatic cancer is one of the deadliest cancers. The expression of miRNAs released into the bloodstream appears to be a good indicator of progression and evaluation of the aggressiveness of pancreatic cancer, as indicated by studies. The work reviewed the latest literature on the importance of miRNAs for pancreatic cancer development.

Biomarkers in the diagnosis of pancreatic cancer: Are we closer to finding the golden ticket?

Pancreatic cancer (PC) is a leading cause of cancer related mortality on a global scale. The disease itself is associated with a dismal prognosis, partly due to its silent nature resulting in patients presenting with advanced disease at the time of diagnosis. To combat this, there has been an explosion in the last decade of potential candidate biomarkers in the research setting in the hope that a diagnostic biomarker may provide a glimmer of hope in what is otherwise quite a substantial clinical dilemma. Currently, serum carbohydrate antigen 19-9 is utilized in the diagnostic work-up of patients diagnosed with PC however this biomarker lacks the sensitivity and specificity associated with a gold-standard marker. In the search for a biomarker that is both sensitive and specific for the diagnosis of PC, there has been a paradigm shift towards a focus on liquid biopsy and the use of diagnostic panels which has subsequently proved to have efficacy in the diagnosis of PC. Currently, promising developments in the field of early detection on PC using diagnostic biomarkers include the detection of microRNA (miRNA) in serum and circulating tumour cells. Both these modalities, although in their infancy and yet to be widely accepted into routine clinical practice, possess merit in the early detection of PC. We reviewed over 300 biomarkers with the aim to provide an in-depth summary of the current state-of-play regarding diagnostic biomarkers in PC (serum, urinary, salivary, faecal, pancreatic juice and biliary fluid).

Exosomal microRNA in Pancreatic Cancer Diagnosis, Prognosis, and Treatment: From Bench to Bedside

Simple Summary

Pancreatic cancer is the fourth leading cause of cancer death in the United States and over 90% of the patients suffer from pancreatic ductal adenocarcinoma (PDAC). PDAC is the most lethal gastrointestinal malignancies and only 10% of the people survive more than 5 years, therefore, novel diagnostic, prognostic, and therapeutic strategies are an immediate necessity. Studies have demonstrated microRNAs in bodily fluids that are bound with membranes (exosomes) can act as stable biomarkers both for disease development and metastasis. The diagnostic, prognostic, as well as therapeutic roles of exosomal microRNAs in pancreatic cancer have been discussed in this review.

Abstract

Pancreatic cancer is the fourth leading cause of cancer death among men and women in the United States, and pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of pancreatic cancer cases. PDAC is one of the most lethal gastrointestinal malignancies with an overall five-year survival rate of ~10%. Developing effective therapeutic strategies against pancreatic cancer is a great challenge. Novel diagnostic, prognostic, and therapeutic strategies are an immediate necessity to increase the survival of pancreatic cancer patients. So far, studies have demonstrated microRNAs (miRNAs) as sensitive biomarkers because of their significant correlation with disease development and metastasis. The miRNAs have been shown to be more stable inside membrane-bound vesicles in the extracellular environment called exosomes. Varieties of miRNAs are released into the body fluids via exosomes depending on the normal physiological or pathological conditions of the body. In this review, we discuss the recent findings on the diagnostic, prognostic, and therapeutic roles of exosomal miRNAs in pancreatic cancer.

Interrelationship between miRNA and splicing factors in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers because of diagnosis at late stage and inherent/acquired chemoresistance. Recent advances in genomic profiling and biology of this disease have not yet been translated to a relevant improvement in terms of disease management and patient’s survival. However, new possibilities for treatment may emerge from studies on key epigenetic factors. Deregulation of microRNA (miRNA) dependent gene expression and mRNA splicing are epigenetic processes that modulate the protein repertoire at the transcriptional level. These processes affect all aspects of PDAC pathogenesis and have great potential to unravel new therapeutic targets and/or biomarkers. Remarkably, several studies showed that they actually interact with each other in influencing PDAC progression. Some splicing factors directly interact with specific miRNAs and either facilitate or inhibit their expression, such as Rbfox2, which cleaves the well-known oncogenic miRNA miR-21. Conversely, miR-15a-5p and miR-25-3p significantly downregulate the splicing factor hnRNPA1 which acts also as a tumour suppressor gene and is involved in processing of miR-18a, which in turn, is a negative regulator of KRAS expression. Therefore, this review describes the interaction between splicing and miRNA, as well as bioinformatic tools to explore the effect of splicing modulation towards miRNA profiles, in order to exploit this interplay for the development of innovative treatments. Targeting aberrant splicing and deregulated miRNA, alone or in combination, may hopefully provide novel therapeutic approaches to fight the complex biology and the common treatment recalcitrance of PDAC.

Tailor-Made Nanomaterials for Diagnosis and Therapy of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide due to its aggressiveness and the challenge to early diagnosis and treatment. In recent decades, nanomaterials have received increasing attention for diagnosis and therapy of PDAC. However, these designs are mainly focused on the macroscopic tumor therapeutic effect, while the crucial nano-bio interactions in the heterogeneous microenvironment of PDAC remain poorly understood. As a result, the majority of potent nanomedicines show limited performance in ameliorating PDAC in clinical translation. Therefore, exploiting the unique nature of the PDAC by detecting potential biomarkers together with a deep understanding of nano-bio interactions that occur in the tumor microenvironment is pivotal to the design of PDAC-tailored effective nanomedicine. This review will introduce tailor-made nanomaterials-enabled laboratory tests and advanced noninvasive imaging technologies for early and accurate diagnosis of PDAC. Moreover, the fabrication of a myriad of tailor-made nanomaterials for various PDAC therapeutic modalities will be reviewed. Furthermore, much preferred theranostic multifunctional nanomaterials for imaging-guided therapies of PDAC will be elaborated. Lastly, the prospects of these nanomaterials in terms of clinical translation and potential breakthroughs will be briefly discussed.

Biomarkers of Chronic Pancreatitis: A systematic literature review

BACKGROUND

Chronic pancreatitis (CP) does not have diagnostic or prognostic biomarkers. CP is the end stage of a progressive inflammatory syndrome that is diagnosed at late stages by morphologic features. To diagnose earlier stages of the disease, a new mechanistic definition was established based on identifying underlying pathogenic processes and biomarker evidence of disease activity and stage. Although multiple risk factors are known, the corresponding biomarkers needed to make a highly accurate diagnosis of earlier disease stages have not been established. The goal of this study is to systematically analyze the literature to identify the most likely candidates for development into biomarkers of CP.

METHODS

We conducted a systematic review of candidate analytes from easily accessible biological fluids and identified 67 studies that compared CP to nonpancreatic-disease controls. We then ranked candidate biomarkers for sensitivity and specificity by area under the receiver operator curves (AUROCs).

RESULTS

Five biomarkers had a large effect size (an AUROC > 0.96), whereas 30 biomarkers had a moderate effect size (an AUROC between 0.96 and 0.83) for distinguishing CP cases from controls or other diseases. However, the studies reviewed had marked variability in design, enrollment criteria, and biospecimen sample handling and collection.

CONCLUSIONS

Several biomarkers have the potential for evaluation in prospective cohort studies and should be correlated with risk factors, clinical features, imaging studies and outcomes. The Consortium for the Study of Chronic Pancreatitis, Diabetes and Pancreas Cancer provides recommendations for avoiding design biases and heterogeneity in sample collection and handling in future studies.

Molecular Approaches Using Body Fluid for the Early Detection of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the most malignant form of gastrointestinal tumor and is the fourth leading cause of deaths due to cancer in Japan. This cancer shows a poor outcome due to the difficulty of its early diagnosis and its rapid growth. Once this disease becomes clinically evident, it is frequently accompanied by distant metastasis at the time of diagnosis. A recent multicenter study in Japan revealed that patients with the early stage of this disease (stage 0 and I) showed favorable prognosis after surgical resection, indicating the importance of early detection for improvement of PDAC prognosis. PDAC develops through a stepwise progression from the precursor lesion, and over the last few decades molecular analyses have shown the detailed genetic alterations that occur in this process. Since advances in molecular technologies have enabled the detection of genetic changes from a very small quantity of samples, a large number of non-invasive molecular approaches have been utilized in an attempt to find precursor or non-invasive carcinoma lesions. In this review, the current efforts in terms of the molecular approaches applied for the early detection of PDAC-especially using body fluids such as pancreatic juice, blood, and saliva-are summarized.

Identification of Circulating Serum miRNAs as Novel Biomarkers in Pancreatic Cancer Using a Penalized Algorithm

Pancreatic cancer (PC) is difficult to detect in the early stages; thus, identifying specific and sensitive biomarkers for PC diagnosis is crucial, especially in the case of early-stage tumors. Circulating microRNAs are promising non-invasive biomarkers. Therefore, we aimed to identify non-invasive miRNA biomarkers and build a model for PC diagnosis. For the training model, blood serum samples from 63 PC patients and 63 control subjects were used. We selected 39 miRNA markers using a smoothly clipped absolute deviation-based penalized support vector machine and built a PC diagnosis model. From the double cross-validation, the average test AUC was 0.98. We validated the diagnosis model using independent samples from 25 PC patients and 81 patients with intrahepatic cholangiocarcinoma (ICC) and compared the results with those obtained from the diagnosis using carbohydrate antigen 19-9. For the markers miR-155-5p, miR-4284, miR-346, miR-7145-5p, miR-5100, miR-661, miR-22-3p, miR-4486, let-7b-5p, and miR-4703-5p, we conducted quantitative reverse transcription PCR using samples from 17 independent PC patients, 8 ICC patients, and 8 healthy individuals. Differential expression was observed in samples from PC patients. The diagnosis model based on the identified markers showed high sensitivity and specificity for PC detection and is potentially useful for early PC diagnosis.

Meta-analysis of the Diagnostic Performance of Circulating MicroRNAs for Pancreatic Cancer

Background: Numerous studies have suggested that differentially expressed miRNAs may be promising diagnostic markers for pancreatic cancer (PC), but the results are inconsistent. We aimed to summarize the diagnostic accuracy of circulating miRNAs, carbohydrate antigen 19-9 (CA19-9), and the combination of miRNAs and CA19-9. Material and Methods: A literature search of online databases including PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI) and WanFang was conducted. Relative data were extracted from eligible included studies, and a meta-analysis was performed. Results: A total of 46 studies involving 4,326 PC patients and 4,277 non-PC controls were included. The pooled sensitivity (SEN), specificity (SPE) and AUC of the circulating miRNAs for differentiating PC patients from non-PC controls were 0.79 (0.77-0.81), 0.77 (0.75-0.79), and 0.85 (0.81-0.87), respectively. The combination of miRNAs and CA19-9 greatly improved the SEN, SPE and AUC to 0.84 (0.80-0.87), 0.91 (0.89-0.93) and 0.94 (0.92-0.96), respectively. Moreover, circulating miRNAs also yielded an acceptable diagnostic accuracy for early-stage PC with a SEN of 0.79 (0.76-0.82), a SPE of 0.74 (0.68-0.79) and an AUC of 0.81 (0.77-0.84). Conclusion: Circulating miRNAs exhibited satisfactory diagnostic performance for PC and even early-stage PC. The combination of circulating miRNAs and CA19-9 can further improve the diagnostic accuracy, providing a novel strategy for PC diagnosis.

Non-coding RNA biomarkers in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, which is usually diagnosed at an advanced stage. The late disease diagnosis, the limited availability of effective therapeutic interventions and lack of robust diagnostic biomarkers, are some of the primary reasons for the dismal 5-year survival rates (∼8%) in patients with PDAC. The pancreatic cancer develops through accumulation of a series of genomic and epigenomic alterations which lead to the transformation of normal pancreatic epithelium into an invasive carcinoma - a process that can take up to 15-20 years to develop, from the occurrence of first initiating mutational event. These facts highlight a unique window of opportunity for the earlier detection of PDAC, which could allow timely disease interception and improvement in the overall survival outcomes in patients suffering from this fatal malignancy. Non-coding RNAs (ncRNAs) have been recognized to play a central role in PDAC pathogenesis and are emerging as attractive candidates for biomarker development in various cancers, including PDAC. More specifically, the ncRNAs play a pivotal role in PDAC biology as they affect tumor growth, migration, and invasion by regulating cellular processes including cell cycle, apoptosis, and epithelial-mesenchymal transition. In this review, we focus on three types of well-established ncRNAs - microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) - and discuss their potential as diagnostic, prognostic and predictive biomarkers in PDAC.

Cell-free microRNAs as Non-invasive Diagnostic and Prognostic Bio- markers in Pancreatic Cancer

Pancreatic cancer (PaC) is one of the most lethal cancers, with an increasing global incidence rate. Unfavorable prognosis largely results from associated difficulties in early diagnosis and the absence of prognostic and predictive biomarkers that would enable an individualized therapeutic approach. In fact, PaC prognosis has not improved for years, even though much efforts and resources have been devoted to PaC research, and the multimodal management of PaC patients has been used in clinical practice. It is thus imperative to develop optimal biomarkers, which would increase diagnostic precision and improve the post-diagnostic management of PaC patients. Current trends in biomarker research envisage the unique opportunity of cell-free microRNAs (miRNAs) present in circulation to become a convenient, non-invasive tool for accurate diagnosis, prognosis and prediction of response to treatment. This review analyzes studies focused on cell-free miRNAs in PaC. The studies provide solid evidence that miRNAs are detectable in serum, blood plasma, saliva, urine, and stool, and that they present easy-to-acquire biomarkers with strong diagnostic, prognostic and predictive potential.

Plasma miR-181a-5p Downregulation Predicts Response and Improved Survival After FOLFIRINOX in Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of the study was to identify plasma microRNA (miRNA) biomarkers for stratifying and monitoring patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) treated with FOLFIRINOX, and to investigate their functional roles.

SUMMARY BACKGROUND DATA

FOLFIRINOX has become a standard therapy for patients with advanced PDAC and can be used to potentially downstage disease. However, only a subset of patients respond, and biomarkers to guide decision-making are urgently needed.

METHODS

We used microarray-based profiling to discover deregulated miRNAs in pre- and postchemotherapy plasma samples from patients based on their progression-free survival (PFS) after FOLFIRINOX. Nine candidate plasma miRNAs were validated in an independent cohort (n = 43). The most discriminative plasma miRNA was correlated with clinicopathological factors and survival, and also investigated in an additional cohort treated with gemcitabine plus nab-paclitaxel. Expression patterns were further evaluated in matched tumor tissues. In vitro studies explored its function, key downstream gene-targets, and interaction with 5-fluorouracil, irinotecan, and oxaliplatin.

RESULTS

Plasma miR-181a-5p was significantly downregulated in non-progressive patients after FOLFIRINOX. In multivariate analysis, this decline correlated with improved PFS and overall survival, especially when combined with CA19-9 decline [hazard ratio (HR) = 0.153, 95% confidence interval (CI), 0.067-0.347 and HR = 0.201, 95% CI, 0.070-0.576, respectively]. This combination did not correlate with survival in patients treated with gemcitabine plus nab-paclitaxel. Tissue expression of miR-181a-5p reflected plasma levels. Inhibition of miR-181a-5p coupled with oxaliplatin exposure in pancreatic cell lines decreased cell viability.

CONCLUSIONS

Plasma miR-181a-5p is a specific biomarker for monitoring FOLFIRINOX response. Decline in plasma miR-181a-5p and CA19-9 levels is associated with better prognosis after FOLFIRINOX and may be useful for guiding therapeutic choices and surgical exploration.

The power of microRNAs as diagnostic and prognostic biomarkers in liquid biopsies

In the last decades, progresses in medical oncology have ameliorated the treatment of patients and their outcome. However, further improvements are still necessary, in particular for certain types of tumors such as pancreatic, gastric, and lung cancer as well as acute myeloid leukemia where early detection and monitoring of the disease are crucial for final patient outcome. Liquid biopsy represents a great advance in the field because it is less invasive, less time-consuming, and safer compared to classical biopsies and it can be useful to monitor the evolution of the disease as well as the response of patients to therapy. Liquid biopsy allows the detection of circulating tumor cells, nucleic acids, and exosomes not only in blood but also in different biological fluids: urine, saliva, pleural effusions, cerebrospinal fluid, and stool. Among the potential biomarkers detectable in liquid biopsies, microRNAs (miRNAs) are gaining more and more attention, since they are easily detectable, quite stable in biological fluids, and show high sensitivity. Many data demonstrate that miRNAs alone or in combination with other biomarkers could improve the diagnostic and prognostic power for many different tumors. Despite this, standardization of methods, sample preparation, and analysis remain challenging and a huge effort should be made to address these issues before miRNA biomarkers can enter the clinic. This review summarizes the main findings in the field of circulating miRNAs in both solid and hematological tumors.

Serum miR-1290 and miR-1246 as Potential Diagnostic Biomarkers of Human Pancreatic Cancer

Background: Pancreatic cancer (PC) is a highly malignant tumor with no effective early diagnostic biomarkers. This study was performed to screen and identify serum microRNAs (miRNAs) as noninvasive biomarkers for PC diagnosis.

Methods: Two upregulated miRNAs were selected by integrated analysis of three independent GEO datasets. Then, the expressions of two miRNAs in serum were determined by quantitative reverse-transcription PCR among 120 PC patients, 40 benign disease controls and 40 healthy controls. The correlation between serum miRNAs and clinical characteristics was analyzed. The diagnostic utility of miRNAs was compared to CA19-9 using receiver operating characteristic curve analysis.

Results: We discovered miR-1290 and miR-1246 were upregulated in PC patients through GEO datasets analysis. Serum miR-1290 and miR-1246 expression levels were elevated in PC patients compared to all controls and dramatically decreased after tumor resection (all P<0.001). The area under the curve (AUC) for miR-1290 was larger than miR-1246 and CA19-9 (miR-1290: 0.91; miR-1246: 0.81; CA19-9: 0.82). The combined diagnosis of individual or both miRNAs with CA19-9 was more effective for discriminating PC from all controls than the single CA19-9 assay (miR-1290+CA19-9: 0.96, miR-1246+CA19-9: 0.93, miR-1290+miR-1246+CA19-9: 0.97). The abundance of serum miR-1290 and miR-1246 was associated with tumor stage and size respectively and logistic modeling proved that both of them were independent risk factors for PC.

Conclusion: Serum miR-1290 and miR-1246 might be promising biomarkers for PC diagnosis and the combined detection of CA19-9, together with miR-1290 or miR-1246, could improve the diagnostic accuracy of PC.

The State of the Art on Blood MicroRNAs in Pancreatic Ductal Adenocarcinoma

Despite enormous advances being made in diagnosis and therapeutic interventions, pancreatic ductal adenocarcinoma (PDAC) is still recognized as one of the most lethal malignancies. Early diagnosis and timely curative surgery can markedly improve the prognosis; hence, there is an unmet necessity to explore efficient biomarkers for patients' benefit. Recently, blood miRNAs (miRNAs) have been reported to be a novel biomarker in human cancers. Part of it is selectively packaged by plasma exosomes released from cells via exocytosis and is highly sensitive to changes in the tumor microenvironment. Furthermore, due to less invasiveness and technical availability, miRNA-based liquid biopsy holds promise for further wide usage. Therefore, this review is aimed at presenting an update on the association between blood miRNAs and the biology of PDAC, then discussing its clinical utilization further.

Noncoding RNAs in Extracellular Fluids as Cancer Biomarkers: The New Frontier of Liquid Biopsies

The last two decades of cancer research have been devoted in two directions: (1) understanding the mechanism of carcinogenesis for an effective treatment, and (2) improving cancer prevention and screening for early detection of the disease. This last aspect has been developed, especially for certain types of cancers, thanks also to the introduction of new concepts such as liquid biopsies and precision medicine. In this context, there is a growing interest in the application of alternative and noninvasive methodologies to search for cancer biomarkers. The new frontiers of the research lead to a search for RNA molecules circulating in body fluids. Searching for biomarkers in extracellular body fluids represents a better option for patients because they are easier to access, less painful, and potentially more economical. Moreover, the possibility for these types of samples to be taken repeatedly, allows a better monitoring of the disease progression or treatment efficacy for a better intervention and dynamic treatment of the patient, which is the fundamental basis of personalized medicine. RNA molecules, freely circulating in body fluids or packed in microvesicles, have all the characteristics of the ideal biomarkers owing to their high stability under storage and handling conditions and being able to be sampled several times for monitoring. Moreover, as demonstrated for many cancers, their plasma/serum levels mirror those in the primary tumor. There are a large variety of RNA species noncoding for proteins that could be used as cancer biomarkers in liquid biopsies. Among them, the most studied are microRNAs, but recently the attention of the researcher has been also directed towards Piwi-interacting RNAs, circular RNAs, and other small noncoding RNAs. Another class of RNA species, the long noncoding RNAs, is larger than microRNAs and represents a very versatile and promising group of molecules which, apart from their use as biomarkers, have also a possible therapeutic role. In this review, we will give an overview of the most common noncoding RNA species detectable in extracellular fluids and will provide an update concerning the situation of the research on these molecules as cancer biomarkers.

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.

Unraveling altered RNA metabolism in pancreatic cancer cells by liquid-chromatography coupling to ion mobility mass spectrometry

Ion mobility coupling to mass spectrometry facilitates enhanced identification certitude. Further coupling to liquid chromatography results in multi-dimensional analytical methods, especially suitable for complex matrices with structurally similar compounds. Modified nucleosides represent a large group of very similar members linked to aberrant proliferation. Besides basal production under physiological conditions, they are increasingly excreted by transformed cells and subsequently discussed as putative biomarkers for various cancer types. Here, we report a method for modified nucleosides covering 37 species. We determined collisional cross-sections with high reproducibility from pure analytical standards. For sample purification, we applied an optimized phenylboronic acid solid-phase extraction on media obtained from four different pancreatic cancer cell lines. Our analysis could discriminate different subtypes of pancreatic cancer cell lines. Importantly, they could clearly be separated from a pancreatic control cell line as well as blank medium. m1A, m27G, and Asm were the most important features discriminating cancer cell lines derived from well-differentiated and poorly differentiated cancers. Eventually, we suggest the analytical method reported here for future tumor-marker identification studies. Graphical abstract.

Plasma Micro-RNA Alterations Appear Late in Pancreatic Cancer

Objectives:

The aim of this research was to study whether plasma microRNAs (miRNA) can be used for early detection of pancreatic cancer (PC) by analyzing prediagnostic plasma samples collected before a PC diagnosis.

Background:

PC has a poor prognosis due to late presenting symptoms and early metastasis. Circulating miRNAs are altered in PC at diagnosis but have not been evaluated in a prediagnostic setting.

Methods:

We first performed an initial screen using a panel of 372 miRNAs in a retrospective case-control cohort that included early-stage PC patients and healthy controls. Significantly altered miRNAs at diagnosis were then measured in an early detection case-control cohort wherein plasma samples in the cases are collected before a PC diagnosis. Carbohydrate antigen 19–9 (Ca 19–9) levels were measured in all samples for comparison.

Results:

Our initial screen, including 23 stage I-II PC cases and 22 controls, revealed 15 candidate miRNAs that were differentially expressed in plasma samples at PC diagnosis. We combined all 15 miRNAs into a multivariate statistical model, which outperformed Ca 19–9 in receiver-operating characteristics analysis. However, none of the candidate miRNAs, individually or in combination, were significantly altered in prediagnostic plasma samples from 67 future PC patients compared with 132 matched controls. In comparison, Ca 19–9 levels were significantly higher in the cases at <5 years before diagnosis.

Conclusion:

Plasma miRNAs are altered in PC patients at diagnosis, but the candidate miRNAs found in this study appear late in the course of the disease and cannot be used for early detection of the disease.

Clinical utilization of serum- or plasma-based miRNAs as early detection biomarkers for pancreatic cancer: A meta-analysis up to now

BACKGROUND

Pancreatic cancer (PC) is a lethal disease, however current screening methods unable to achieve early diagnosis. Blood-based microRNAs (miRNAs) are promising molecular biomarkers for detecting PC. This meta-analysis summaries studies identifying serum- or plasma-based miRNAs dysregulated in PC patients compared to non-PC cases to evaluate their diagnostic accuracy for characterizing PC.

METHODS

A systematically reviews and meta-analysis of published studies was conducted to compare the serum or plasma miRNAs expressions between PC patients and non-PC cases. Summary estimates for sensitivity, specificity, along with other measures of accuracy of miRNAs in the diagnosis of PC were pooled using the random-effects model. I and Q tests were used to assess the heterogeneity of included studies. The Spearman test was used to analyze the threshold effect.

RESULTS

Twenty-seven eligible studies were identified after electronic search and literature selection. For single miRNA dysregulation, 32 miRNAs were found to be upregulated in PC patients, and 5 miRNAs were downregulated. Four studies identified a 2-miRNA panel, and 10 studies identified a panel consisting of 3 or more miRNAs which were used to detect PC patients. Additionally, 8 studies combined miRNA panels and carbohydrate antigen 19-9 (CA 19-9) to diagnose PC. The pooled sensitivities for these 4 groups were 0.77 to 0.85, and specificities were 0.70 to 0.87. The highest area under the curve (AUC), 0.9308, was identified using 2 miRNA panels with sensitivity and specificity of 0.79 (0.74-0.83) and 0.85 (0.81-0.89), respectively. There was great heterogeneity of these 4 miRNA groups. Results of Spearman test revealed that there existed a threshold effect on single miRNA group (r=-0.437, P=.001), and none of the other groups (P all>.05).

CONCLUSIONS

Serum- or plasma-based miRNAs are capable of distinguishing PC from non-PC with relatively high sensitivity and specificity. In future, miRNAs may be used as promising diagnostic biomarkers for detection of PC.

Analysis of miR-148b expression differences in stage-I and II parosteal osteosarcoma

Expression of human serum albumin-micro RNA miR-148b in patients with stage-I and II parosteal osteosarcoma and its effect on prognosis were investigated. A total of 47 cases of fresh tissues of stage-I and II parosteal osteosarcoma and the corresponding para-carcinoma normal bone tissues resected by operation were collected; the expression of miR-148b in parosteal osteosarcoma tissues and normal bone tissues was detected, and the correlations of miR-148b expression in parosteal osteosarcoma tissues with clinicopathological parameters and prognosis were analyzed. The expression level of miR-148b in parosteal osteosarcoma tissues was significantly lower than that in para-carcinoma normal tissues (P<0.05). It was found that the low expression of miR-148b was correlated with the lung metastasis (P<0.05). Moreover, Kaplan-Meier survival curve analysis showed that the overall survival rate of patients in the low-expression miR-148b group was lower than that in the high-expression group (P<0.05). Multivariate Cox regression analysis revealed that the miR-148b level (P=0.003) was an independent prognostic factor affecting the prognosis. The results of this study showed that the expression of miR-148b in stage-I and II parosteal osteosarcoma tissues declines, which is related to the poor clinical prognosis of parosteal osteosarcoma.

Blood-Derived microRNAs for Pancreatic Cancer Diagnosis: A Narrative Review and Meta-Analysis

microRNAs (miRNAs) have been reported to be aberrantly expressed in patients with pancreatic cancer. In present review we explored the biological roles of miRNAs in pancreatic cancer and their clinical value in diagnosis. In the systematic review, the potential value of miRNAs as biomarkers was investigated by reviewing the altered miRNA profiles reported in pancreatic cancer patients in 356 included studies. In the subsequent meta-analysis, we included 17 studies in early diagnosis of pancreatic cancer with a panel of altered miRNAs. The following results were obtained: pooled sensitivity of 0.88 (95% confidence interval [CI] 0.83–0.92), pooled specificity of 0.83 (95%CI 0.77–0.88), diagnostic odds ratio of 27 (95%CI 14–53), and area under the receiver operating characteristic curve of 0.90 (95%CI 0.88–0.93). To further explore the value of a single miRNA, the diagnostic value of miR-21 in PA was also demonstrated by the pooled sensitivity (0.90, 95% CI: 0.82–0.94), specificity (0.72, 95% CI: 0.57-0.83) as well as AUC (0.91 (95%CI 0.88–0.93). In conclusion, our findings suggest that aberrant miRNA expression in blood play an essential role in pancreatic cancer, and meta-analysis revealed blood-derived miRNAs as probable biomarkers for early diagnosis of pancreatic cancer.

Systematic Review and Meta-Analysis of Diagnostic Accuracy of miRNAs in Patients with Pancreatic Cancer

Background

It is reported that miRNAs are aberrantly expressed in patients with pancreatic cancer. However, the diagnostic value of miRNAs in pancreatic cancer remains controversial. The meta-analysis was to access diagnostic accuracy of miRNAs in pancreatic cancer.

Methods

PubMed, Scopus, Web of Science, Chinese National Knowledge Infrastructure (CNKI), WANFANG Data, China Biomedical Literature Database (CBM), and VIP databases were retrieved up to June 30, 2016, to collect articles concerning the diagnosis of miRNAs in pancreatic cancer. The methodological quality of each study was assessed by the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). This meta-analysis was conducted using RevMan5.0, MetaDiSc 1.4, and Stata 12.0 software.

Results

There are 40 articles including 109 studies. The pooled SEN was 0.81 (95% CI, 0.80–0.82), the pooled SPE was 0.78 (95% CI, 0.77–0.79), the pooled +LR was 3.32 (95% CI, 2.92–3.80), the pooled −LR was 0.27 (95% CI, 0.24–0.31), the pooled DOR was 14.56 (95% CI, 11.55–18.34), and pooled AUC was 0.86 (95% CI, 0.84–0.88).

Discussion

This meta-analysis demonstrated that miRNA makes a significant impact in the pancreatic cancer diagnosis with a high SEN and SPE, particularly using multiple miRNAs.

Diagnostic value of microRNAs in asbestos exposure and malignant mesothelioma: systematic review and qualitative meta-analysis

Background

Asbestos is a harmful and exceptionally persistent natural material. Malignant mesothelioma (MM), an asbestos-related disease, is an insidious, lethal cancer that is poorly responsive to current treatments. Minimally invasive, specific, and sensitive biomarkers providing early and effective diagnosis in high-risk patients are urgently needed. MicroRNAs (miRNAs, miRs) are endogenous, non-coding, small RNAs with established diagnostic value in cancer and pollution exposure. A systematic review and a qualitative meta-analysis were conducted to identify high-confidence miRNAs that can serve as biomarkers of asbestos exposure and MM.

Methods

The major biomedical databases were systematically searched for miRNA expression signatures related to asbestos exposure and MM. The qualitative meta-analysis applied a novel vote-counting method that takes into account multiple parameters. The most significant miRNAs thus identified were then subjected to functional and bioinformatic analysis to assess their biomarker potential.

Results

A pool of deregulated circulating and tissue miRNAs with biomarker potential for MM was identified and designated as “mesomiRs” (MM-associated miRNAs). Comparison of data from asbestos-exposed and MM subjects found that the most promising candidates for a multimarker signature were circulating miR-126-3p, miR-103a-3p, and miR-625-3p in combination with mesothelin. The most consistently described tissue miRNAs, miR-16-5p, miR-126-3p, miR-143-3p, miR-145-5p, miR-192-5p, miR-193a-3p, miR-200b-3p, miR-203a-3p, and miR-652-3p, were also found to provide a diagnostic signature and should be further investigated as possible therapeutic targets.

Conclusion

The qualitative meta-analysis and functional investigation confirmed the early diagnostic value of two miRNA signatures for MM. Large-scale, standardized validation studies are needed to assess their clinical relevance, so as to move from the workbench to the clinic.

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.