Tissue MicroRNA profiles as diagnostic and prognostic biomarkers in patients with resectable pancreatic ductal adenocarcinoma and periampullary cancers

Using microRNAs Networks to Understand Pancreatic Cancer-A Literature Review

Pancreatic cancer is a severe disease, challenging to diagnose and treat, and thereby characterized by a poor prognosis and a high mortality rate. Pancreatic ductal adenocarcinoma (PDAC) represents approximately 90% of pancreatic cancer cases, while other cases include neuroendocrine carcinoma. Despite the growing knowledge of the pathophysiology of this cancer, the mortality rate caused by it has not been effectively reduced. Recently, microRNAs have aroused great interest among scientists and clinicians, as they are negative regulators of gene expression, which participate in many processes, including those related to the development of pancreatic cancer. The aim of this review is to show how microRNAs (miRNAs) affect key signaling pathways and related cellular processes in pancreatic cancer development, progression, diagnosis and treatment. We included the results of in vitro studies, animal model of pancreatic cancer and those performed on blood, saliva and tumor tissue isolated from patients suffering from PDAC. Our investigation identified numerous dysregulated miRNAs involved in KRAS, JAK/STAT, PI3/AKT, Wnt/β-catenin and TGF-β signaling pathways participating in cell cycle control, proliferation, differentiation, apoptosis and metastasis. Moreover, some miRNAs (miRNA-23a, miRNA-24, miRNA-29c, miRNA-216a) seem to be engaged in a crosstalk between signaling pathways. Evidence concerning the utility of microRNAs in the diagnosis and therapy of this cancer is poor. Therefore, despite growing knowledge of the involvement of miRNAs in several processes associated with pancreatic cancer, we are beginning to recognize and understand their role and usefulness in clinical practice.

Acrylamide-targeting renal miR-21a-5p/Fibrotic and miR122-5p/ inflammatory signaling pathways and the role of a green approach for nano-zinc detected via in silico and in vivo approaches

Introduction: Any disruption in renal function can have cascading effects on overall health. Understanding how a heat-born toxicant like acrylamide (ACR) affects kidney tissue is vital for realizing its broader implications for systemic health. Methods: This study investigated the ACR-induced renal damage mechanisms, particularly focusing on the regulating role of miR-21a-5p/fibrotic and miR-122-5p/inflammatory signaling pathways via targeting Timp-3 and TP53 proteins in an In silico preliminary study. Besides, renal function assessment, oxidative status, protein profile, and the expression of renal biomarkers (Timp-1, Keap-1, Kim-1, P53, TNF-α, Bax, and Caspase3) were assessed in a 60-day experiment. The examination was additionally extended to explore the potential protective effects of green-synthesized zinc oxide nanoparticles (ZNO-MONPs). A four-group experiment including control, ZNO-MONPs (10 mg/kg b.wt.), ACR (20 mg/kg b.wt.), and ZNO-MONPs + ACR was established encompassing biochemical, histological, and molecular levels. The study further investigated the protein-binding ability of ZNO and MONPs to inactivate caspase-3, Keap-1, Kim-1, and TNFRS-1A. Results: ZNO-MONPs significantly reduced ACR-induced renal tissue damage as evidenced by increased serum creatinine, uric acid, albumin, and oxidative stress markers. ACR-induced oxidative stress, apoptosis, and inflammationare revealed by biochemical tests, gene expression, and the presence of apoptotic nuclei microscopically. Also, molecular docking revealed binding affinity between ACR-BCL-2 and glutathione-synthetase, elucidating the potential mechanisms through which ACR induces renal damage. Notably, ZNO-MONPs revealed a protective potential against ACR-induced damage. Zn levels in the renal tissues of ACR-exposed rats were significantly restored in those treated with ACR + ZNO-MONPs. In conclusion, this study establishes the efficacy of ZNO-MONPs in mitigating ACR-induced disturbances in renal tissue functions, oxidative stress, inflammation, and apoptosis. The findings shed light on the potential renoprotective activity of green-synthesized nanomaterials, offering insights into novel therapeutic approaches for countering ACR-induced renal damage.

MicroRNAs in Pancreatic Cancer: Advances in Biomarker Discovery and Therapeutic Implications

Pancreatic cancer remains a formidable malignancy characterized by high mortality rates, primarily attributable to late-stage diagnosis and a dearth of effective therapeutic interventions. The identification of reliable biomarkers holds paramount importance in enhancing early detection, prognostic evaluation, and targeted treatment modalities. Small non-coding RNAs, particularly microRNAs, have emerged as promising candidates for pancreatic cancer biomarkers in recent years. In this review, we delve into the evolving role of cellular and circulating miRNAs, including exosomal miRNAs, in the diagnosis, prognosis, and therapeutic targeting of pancreatic cancer. Drawing upon the latest research advancements in omics data-driven biomarker discovery, we also perform a case study using public datasets and address commonly identified research discrepancies, challenges, and limitations. Lastly, we discuss analytical approaches that integrate multimodal analyses incorporating clinical and molecular features, presenting new insights into identifying robust miRNA-centric biomarkers.

microRNA-622 upregulates cell cycle process by targeting FOLR2 to promote CRC proliferation

BACKGROUND

Epigenetic alterations contribute greatly to the development and progression of colorectal cancer, and effect of aberrant miR-622 expression is still controversial. This study aimed to discover miR-622 regulation in CRC proliferation.

METHODS

miR-622 expression and prognosis were analyzed in clinical CRC samples from Nanfang Hospital. miR-622 regulation on cell cycle and tumor proliferation was discovered, and FOLR2 was screened as functional target of miR-622 using bioinformatics analysis, which was validated via dual luciferase assay and gain-of-function and loss-of-function experiments both in vitro and in vivo.

RESULTS

miR-622 overexpression in CRC indicated unfavorable prognosis and it regulated cell cycle to promote tumor growth both in vitro and in vivo. FOLR2 is a specific, functional target of miR-622, which negatively correlates with signature genes in cell cycle process to promote CRC proliferation.

CONCLUSIONS

miR-622 upregulates cell cycle process by targeting FOLR2 to promote CRC proliferation, proposing a novel mechanism and treatment target in CRC epigenetic regulation of miR-622.

Research Progress of Aging-related MicroRNAs

Senescence refers to the irreversible state in which cells enter cell cycle arrest due to internal or external stimuli. The accumulation of senescent cells can lead to many age-related diseases, such as neurodegenerative diseases, cardiovascular diseases, and cancers. MicroRNAs are short non-coding RNAs that bind to target mRNA to regulate gene expression after transcription and play an important regulatory role in the aging process. From nematodes to humans, a variety of miRNAs have been confirmed to alter and affect the aging process. Studying the regulatory mechanisms of miRNAs in aging can further deepen our understanding of cell and body aging and provide a new perspective for the diagnosis and treatment of aging-related diseases. In this review, we illustrate the current research status of miRNAs in aging and discuss the possible prospects for clinical applications of targeting miRNAs in senile diseases.

The Impact of miR-122 on Cancer

MiRNAs are confirmed to be a kind of short and eminently conserved noncoding RNAs, which regulate gene expression at the post-transcriptional level via binding to the 3'- untranslated region (3'-UTR) of targeting multiple target messenger RNAs. Recently, growing evidence stresses the point that they play a crucial role in a variety of pathological processes, including human cancers. Dysregulated miRNAs act as oncogenes or tumor suppressor genes in many cancer types. Among them, we noticed that miR-122 has been widely reported to significantly influence carcinogenicity in a variety of tumors by regulating target genes and signaling pathways. Here, we focused on the expression of miR-122 in regulatory mechanisms and tumor biological processes. We also discussed the effects of miR-122 dysregulation in various types of human malignancies and the potential to develop new molecular miR-122-targeted therapies. The present review suggests that miR-122 may be a potentially useful cancer diagnosis and treatment biomarker. More clinical diagnoses need to be further launched in the future. A promising direction to improve the outcomes for cancer patients will likely combine miR-122 with other traditional tumor biomarkers.

The role and mechanism of action of microRNA-122 in cancer: Focusing on the liver

microRNA-122 (miR-122) is a highly conserved microRNA that is predominantly expressed in the liver and plays a critical role in the regulation of liver metabolism. Recent studies have shown that miR-122 is involved in the pathogenesis of various types of cancer, particularly liver cancer. In this sense, The current findings highlighted the potential role of miR-122 in regulating many vital processes in cancer pathophysiology, including apoptosis, signaling pathway, cell metabolism, immune system response, migration, and invasion. These results imply that miR-122, which has been extensively studied for its biological functions and potential therapeutic applications, acts as a tumor suppressor or oncogene in cancer development. We first provide an overview and summary of the physiological function and mode of action of miR-122 in liver cancer. We will examine the various signaling pathways and molecular mechanisms through which miR-122 exerts its effects on cancer cells, including the regulation of oncogenic and tumor suppressor genes, the modulation of cell proliferation and apoptosis, and the regulation of metastasis. Most importantly, we will also discuss the potential diagnostic and therapeutic applications of miR-122 in cancer, including the development of miRNA-based biomarkers for cancer diagnosis and prognosis, and the potential use of miR-122 as a therapeutic target for cancer treatment.

miR-122-5p is involved in posttranscriptional regulation of the mitochondrial thiamin pyrophosphate transporter (SLC25A19) in pancreatic acinar cells

Thiamin (vitamin B1) plays a vital role in cellular energy metabolism/ATP production. Pancreatic acinar cells (PACs) obtain thiamin from circulation and convert it to thiamin pyrophosphate (TPP) in the cytoplasm. TPP is then taken up by the mitochondria via a carrier-mediated process that involves the mitochondrial TPP transporter (MTPPT; encoded by the gene SLC25A19). We have previously characterized different aspects of the mitochondrial carrier-mediated TPP uptake process, but nothing is known about its possible regulation at the posttranscriptional level. We address this issue in the current investigations focusing on the role of miRNAs in this regulation. First, we subjected the human (and rat) 3'-untranslated region (3'-UTR) of the SLC25A19 to three in-silico programs, and all have identified putative binding sites for miR-122-5p. Transfecting pmirGLO-hSLC25A19 3'-UTR into rat PAC AR42J resulted in a significant reduction in luciferase activity compared with cells transfected with pmirGLO-empty vector. Mutating as well as truncating the putative miR-122-5p binding sites in the hSLC25A19 3'-UTR led to abrogation of inhibition in luciferase activity in PAC AR42J. Furthermore, transfecting/transducing PAC AR42J and human primary PACs with mimic of miR-122-5p led to a significant inhibition in the level of expression of the MTPPT mRNA and protein as well as in mitochondrial carrier-mediated TPP uptake. Conversely, transfecting PAC AR42J with an inhibitor of miR-122-5p increased MTPPT expression and function. These findings show, for the first time, that expression and function of the MTPPT in PACs are subject to posttranscriptional regulation by miR-122-5p.NEW & NOTEWORTHY This study shows that the expression and function of mitochondrial TPP transporter (MTPPT) are subject to posttranscriptional regulation by miRNA-122-5p in pancreatic acinar cells.

Identification of key microRNAs in exosomes derived from patients with the severe acute pancreatitis

OBJECTIVE

Exosomes have been identified as important carriers of various genetic materials, including microRNAs (miRNAs). Increasing evidence indicates that the course of severe acute pancreatitis (SAP) is associated with miRNAs transported by exosomes. We aimed to identify the signature miRNAs as biomarkers of SAP.

METHODS

We obtained exosomes from the SAP patients' blood. After separation, purification, and identification, we performed high-throughput sequencing and screened the differentially expressed(DE) miRNAs in the exosomes. Bioinformatics analysis was performed to identified the target genes of the miRNAs and the pathways enriched based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, and selected the key miRNAs related to SAP. Total RNA was extracted from patient serum exosomes to detect the expression levels of the selected miRNAs in exosomes of three experimental groups (mild -, moderately severe -, and severe AP) and a control group, using Real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

272 DE miRNAs were identified between SAP and control group. Using bioinformatics analysis, we determined that the functions of the target genes were enriched in six signaling pathways including focal adhesion. Based on this, seven candidate signature miRNAs were selected: miR-603, miR-548ad-5p, miR-122-5p, miR-4477a, miR-192-5p, miR-215-5p, and miR-583. The RT-qPCR results of the seven miRNAs in the SAP group were consistent with the sequencing results.

CONCLUSION

Exosome-derived miR-603, miR-548ad-5p, miR-122-5p, miR-4477a, miR-192-5p, miR-215-5p, miR-583 are positively correlated with SAP, which might provide new insights into the pathogenesis of SAP and serve as the biomarkers of SAP.

Molecular pathways in periampullary cancer: An overview

Molecular alterations in oncogenes and tumor suppressors in various signaling pathways are basis for personalized therapy in cancer. Periampullary carcinoma behaves differently from pancreatic carcinoma both in prognosis and outcome, therefore it needs special attention. Pancreatic cancer have higher incidence of nodal spread and perineural &lymphovascular invasion suggesting it biologically more aggressive tumor compared to periampullary cancer. Since PAC tumors consist of heterogenous tissue of origin, they might contain different mutations in tumor associated genes and other changes in tissue composition among different subgroups clubbed together. Significant progress has been made in understanding the molecular nature of PAC in the previous two decades, and a large number of mutations and other genetic changes have been identified as being responsible for the disease. This review article targets to collate and discuss the molecular evolution of PAC and their implication in its outcome. As per literature, mitogen-activated protein kinase (MAPK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), and Wnt signaling are the most common pathways involved in PAC. Mutations in KRAS, TP53, CTNNB1, SMAD4 and APC genes were the most frequently reported. I-subtype resembles colorectal cancer while the morphology of PB-type shows close resemblance to pancreatic tumors. The frequency of driver gene mutations is higher in I-type compared to PB-type of PAC indicating I-type to be genetically more unstable. The genetic landscape of PAC obtained from WES data highlighted PI3/AKT pathway to be a primary target in I-type and RAS/RAF in PB-type.

Review of the endocrine organ-like tumor hypothesis of cancer cachexia in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal types of solid tumors, associated with a high prevalence of cachexia (~80%). PDAC-derived cachexia (PDAC-CC) is a systemic disease involving the complex interplay between the tumor and multiple organs. The endocrine organ-like tumor (EOLT) hypothesis may explain the systemic crosstalk underlying the deleterious homeostatic shifts that occur in PDAC-CC. Several studies have reported a markedly heterogeneous collection of cachectic mediators, signaling mechanisms, and metabolic pathways, including exocrine pancreatic insufficiency, hormonal disturbance, pro-inflammatory cytokine storm, digestive and tumor-derived factors, and PDAC progression. The complexities of PDAC-CC necessitate a careful review of recent literature summarizing cachectic mediators, corresponding metabolic functions, and the collateral impacts on wasting organs. The EOLT hypothesis suggests that metabolites, genetic instability, and epigenetic changes (microRNAs) are involved in cachexia development. Both tumors and host tissues can secrete multiple cachectic factors (beyond only inflammatory mediators). Some regulatory molecules, metabolites, and microRNAs are tissue-specific, resulting in insufficient energy production to support tumor/cachexia development. Due to these complexities, changes in a single factor can trigger bi-directional feedback circuits that exacerbate PDAC and result in the development of irreversible cachexia. We provide an integrated review based on 267 papers and 20 clinical trials from PubMed and ClinicalTrials.gov database proposed under the EOLT hypothesis that may provide a fundamental understanding of cachexia development and response to current treatments.

STAM binding protein regulated by hsa_circ_0007334 exerts oncogenic potential in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a highly aggressive and metastatic malignancy. The molecular events related to PC have not yet been fully elucidated. The STAM binding protein (STAMBP), a deubiquitinase, contributes to carcinogenesis in several types of cancer. Our study aims to investigate the function of STAMBP in the progression of PC.

METHODS

Fifteen pairs of tumor and tumor-adjacent tissues were obtained from PC patients. Human pancreatic cancer cell lines, SW 1990 and BxPC-3, were transfected with short hairpin RNA targeting STAMBP or/and vectors overexpressing wild-type STAMBP or STAMBP D348A mutants (inactive mutants of STAMBP). SW 1990 cells were co-transfected with vectors overexpressing STAMBP and small interfering RNA targeting hsa_circ_0007334.

RESULTS

STAMBP was overexpressed in the tumor tissues as compared with the tumor-adjacent tissues from PC patients. Higher STAMBP expression in the tumor tissues showed worse prognosis. Loss/gain-of-function experiments revealed that STAMBP promoted the malignant behaviors of PC cells in vitro and xenograft tumor growth in vivo. Activation of NF-κB in PC cells was triggered by STAMBP. However, inactive mutants of STAMBP lost these biological functions in PC. hsa_circ_0007334, an oncogene in PC progression, was found to up-regulate STAMBP expression in PC cells. STAMBP up-regulation reversed the effects of hsa_circ_0007334 silencing on cell mobility.

CONCLUSIONS

These results indicated that STAMBP depended on its deubiquitinase activities to induce the malignant behaviors of PC cells and was involved in the regulatory mechanism of hsa_circ_0007334 on PC cell mobility. Our findings provide a novel insight into the molecular mechanism of PC.

Tumor-targeted miRNA nanomedicine for overcoming challenges in immunity and therapeutic resistance

miRNA are critical messengers in the tumor microenvironment (TME) that influence various processes leading to immune suppression, tumor progression, metastasis and resistance. Strategies to modulate miRNAs in the TME have important implications in overcoming these challenges. However, miR delivery to specific cells in the TME has been challenging. This review discusses nanomedicine strategies to achieve cell-specific delivery of miRNAs. The key goal of delivery is to activate the tumor immune landscape as well as to prevent chemotherapy resistance. Specifically, the use of hyaluronic acid-based nanoparticle miRNA delivery to the TME is discussed. The discussion is focused on miRNA-125b for reprogramming tumor-associated macrophages to overcome immunosuppression and miRNA-let-7b to overcome resistance to anticancer chemotherapeutics because both these miRNAs have been extensively evaluated for delivery with hyaluronic acid-based delivery systems.

Curcumol inhibits the growth of xenograft-tumors in mice and the biological activities of pancreatic cancer cells by regulating the miR-21-5p/SMAD7 axis

Anti-cancer effects of curcumol on various cancers have been reported previously. This study focused on investigating the role of curcumol in pancreatic cancer from the molecular perspective. The survival of pancreatic cancer patients with high or low expression of miR-21-5pand the target gene of miR-21-5pwere analyzed by bioinformatics. MiR-21-5p expression in cancer tissues was analyzed by RT-qPCR. Anxenograft-tumor BALB/c nude mice model was established and pancreatic cancer cells were cultured. Later, the mice and cells were further treated with curcumol. The tumor size and weightas well as mice body weight were recorded. The viability, proliferation, migration, and invasion of the cells were evaluated by MTT, colony formation, and transwell assays, respectively. The expressions of molecules in the xenograft-tumor tissues or cells were detected by immunohistochemical assay, Western blot, or RT-qPCR. MiR-21-5p was high-expressed in pancreatic cancer tissues and patients with high expression of miR-21-5p had poor survival. Curcumol inhibited the xenograft-tumor size, tumor weight, and PCNA and miR-21-5p expressions while promoting Cleaved caspase-3 expression in xenograft-tumor tissues. Curcumol inhibited the viability, proliferation, migration, invasion, and miR-21-5p expression, but increased SMAD7 expression in cancer cells. MiR-21-5p overexpression reversed the effect of curcumol on cancer cells, and decreased the E-cadherin expression while elevating the expressions of PCNA, N-cadherin, Vimentin, p-SMAD2, and p-SMAD3 in curcumol-treated cells. The overexpression of SMAD7, a target gene of miR-21-5p, reversed the effect of miR-21-5p on curcumol-treated cells. Curcumol inhibited growth of xenograft-tumors and the biological activities of pancreatic cancer cells by regulating the miR-21-5p/SMAD7 axis.

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18-24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl2) in vitro. Lethal concentration (LC50) values for CdCl2 resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl2, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial-mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

The Metabolism Reprogramming of microRNA Let-7-Mediated Glycolysis Contributes to Autophagy and Tumor Progression

Cancer is usually a result of abnormal glucose uptake and imbalanced nutrient metabolization. The dysregulation of glucose metabolism, which controls the processes of glycolysis, gives rise to various physiological defects. Autophagy is one of the metabolic-related cellular functions and involves not only energy regeneration but also tumorigenesis. The dysregulation of autophagy impacts on the imbalance of metabolic homeostasis and leads to a variety of disorders. In particular, the microRNA (miRNA) Let-7 has been identified as related to glycolysis procedures such as tissue repair, stem cell-derived cardiomyocytes, and tumoral metastasis. In many cancers, the expression of glycolysis-related enzymes is correlated with Let-7, in which multiple enzymes are related to the regulation of the autophagy process. However, much recent research has not comprehensively investigated how Let-7 participates in glycolytic reprogramming or its links to autophagic regulations, mainly in tumor progression. Through an integrated literature review and omics-related profiling correlation, this review provides the possible linkage of the Let-7 network between glycolysis and autophagy, and its role in tumor progression.

Non-coding RNAs in pancreatic ductal adenocarcinoma: New approaches for better diagnosis and therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with a 5-year survival rate less than 8%, which has remained unchanged over the last 50 years. Early detection is particularly difficult due to the lack of disease-specific symptoms and a reliable biomarker. Multimodality treatment including chemotherapy, radiotherapy (used sparingly) and surgery has become the standard of care for patients with PDAC. Carbohydrate antigen 19-9 (CA 19-9) is the most common diagnostic biomarker; however, it is not specific enough especially for asymptomatic patients. Non-coding RNAs are often deregulated in human malignancies and shown to be involved in cancer-related mechanisms such as cell growth, differentiation, and cell death. Several micro, long non-coding and circular RNAs have been reported to date which are involved in PDAC. Aim of this review is to discuss the roles and functions of non-coding RNAs in diagnosis and treatments of PDAC.

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.

Pancreatic Cancer and Therapy: Role and Regulation of Cancer Stem Cells

Despite significant improvements in clinical management, pancreatic cancer (PC) remains one of the deadliest cancer types, as it is prone to late detection with extreme metastatic properties. The recent findings that pancreatic cancer stem cells (PaCSCs) contribute to the tumorigenesis, progression, and chemoresistance have offered significant insight into the cancer malignancy and development of precise therapies. However, the heterogeneity of cancer and signaling pathways that regulate PC have posed limitations in the effective targeting of the PaCSCs. In this regard, the role for K-RAS, TP53, Transforming Growth Factor-β, hedgehog, Wnt and Notch and other signaling pathways in PC progression is well documented. In this review, we discuss the role of PaCSCs, the underlying molecular and signaling pathways that help promote pancreatic cancer development and metastasis with a specific focus on the regulation of PaCSCs. We also discuss the therapeutic approaches that target different PaCSCs, intricate mechanisms, and therapeutic opportunities to eliminate heterogeneous PaCSCs populations in pancreatic cancer.

Panel of serum miRNAs as potential non-invasive biomarkers for pancreatic ductal adenocarcinoma

Early-stage diagnosis of pancreatic ductal adenocarcinoma (PDAC) is difficult due to non-specific symptoms. Circulating miRNAs in body fluids have been emerging as potential non-invasive biomarkers for diagnosis of many cancers. Thus, this study aimed to assess a panel of miRNAs for their ability to differentiate PDAC from chronic pancreatitis (CP), a benign inflammatory condition of the pancreas. Next-generation sequencing was performed to identify miRNAs present in 60 FFPE tissue samples (27 PDAC, 23 CP and 10 normal pancreatic tissues). Four up-regulated miRNAs (miR-215-5p, miR-122-5p, miR-192-5p, and miR-181a-2-3p) and four down-regulated miRNAs (miR-30b-5p, miR-216b-5p, miR-320b, and miR-214-5p) in PDAC compared to CP were selected based on next-generation sequencing results. The levels of these 8 differentially expressed miRNAs were measured by qRT-PCR in 125 serum samples (50 PDAC, 50 CP, and 25 healthy controls (HC)). The results showed significant upregulation of miR-215-5p, miR-122-5p, and miR-192-5p in PDAC serum samples. In contrast, levels of miR-30b-5p and miR-320b were significantly lower in PDAC as compared to CP and HC. ROC analysis showed that these 5 miRNAs can distinguish PDAC from both CP and HC. Hence, this panel can serve as a non-invasive biomarker for the early detection of PDAC.

High Levels of Prebiotic Resistant Starch in Diet Modulate a Specific Pattern of miRNAs Expression Profile Associated to a Better Overall Survival in Pancreatic Cancer

Dietary patterns are well known risk factors involved in cancer initiation, progression, and in cancer protection. Previous in vitro and in vivo studies underline the link between a diet rich in resistant starch (RS) and slowing of tumor growth and gene expression in pancreatic cancer xenograft mice. The aim of this study was to investigate the impact of a diet rich in resistant starch on miRNAs and miRNAs-target genes expression profile and on biological processes and pathways, that play a critical role in pancreatic tumors of xenografted mice. miRNA expression profiles on tumor tissues displayed 19 miRNAs as dysregulated in mice fed with RS diet as compared to those fed with control diet and differentially expressed miRNA-target genes were predicted by integrating (our data) with a public human pancreatic cancer gene expression dataset (GSE16515). Functional and pathway enrichment analyses unveiled that miRNAs involved in RS diet are critical regulators of genes that control tumor growth and cell migration and metastasis, inflammatory response, and, as expected, synthesis of carbohydrate and glucose metabolism disorder. Mostly, overall survival analysis with clinical data from TCGA (n = 175) displayed that almost four miRNAs (miRNA-375, miRNA-148a-3p, miRNA-125a-5p, and miRNA-200a-3p) upregulated in tumors from mice fed with RS were a predictor of good prognosis for pancreatic cancer patients. These findings contribute to the understanding of the potential mechanisms through which resistant starch may affect cancer progression, suggesting also a possible integrative approach for enhancing the efficacy of existing cancer treatments.

Serum miR-210-3p can be used to differentiate between patients with pancreatic ductal adenocarcinoma and chronic pancreatitis

Patients with chronic pancreatitis (CP) are at risk of developing pancreatic ductal adenocarcinoma (PDAC). To the best of our knowledge, there are no suitable non-invasive biomarkers for differentiation between CP and PDAC; however, potential molecular candidates include circulating miRNAs due to ease of extraction, their stability and tissue specificity. Therefore, the aim of the present study was to identify potential serum marker(s) that may be used for differentiating between CP and PDAC. In total, 77 patients were enrolled in the present study; 34 patients with CP, 26 patients with PDAC and a control group of 17 healthy individuals. Expression of miR-10b-5p, miR-106b-5p, miR-210-3p and miR-216a-5p in serum was determined by reverse transcription-quantitative PCR. Serum miRNA expression levels in patients with CP, PDAC and in the control group were compared. Routine biochemical blood parameters were determined and correlation analysis of these parameters with miRNA expression was performed. Expression of miR-210-3p was increased in the sera of patients with PDAC compared with the CP patients (P=0.015) and with the control group (P<0.001). MiR-106b-5p (P=0.056) and miR-10b-5p (P=0.080) were not significantly upregulated in patients with PDAC compared with those with CP. Analysis of miRNA expression in relation to laboratory blood parameters showed positive correlations between miR-210-3p with alkaline phosphatase (r=0.605; P=0.022) and with γ-glutamyltranspeptidase (r=0.529; P=0.029) in PDAC. The novel finding of the present study was that miR-10b-5p was positively correlated with C-reactive protein (r=0.429; P=0.047) in patients with PDAC and with carbohydrate antigen 19-9 (r=0.483; P=0.005) in CP. Based on the preliminary data obtained in the present study, it was concluded that miR-210-3p may be used as a non-invasive biomarker that can be used to distinguish between patients with PDAC and CP.

Prognostic Impact of let-7e MicroRNA and Its Target Genes in Localized High-Risk Intestinal GIST: A Spanish Group for Research on Sarcoma (GEIS) Study

MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level, and they have been described as being associated with tumor prognosis. Here, miRNA profiling was planned to explore new molecular prognostic biomarkers in localized intestinal high-risk GIST. Paraffin tumor blocks of 14 and 86 patients were used in the discovery and expansion sets, respectively. GeneChip miRNA v3.0 was employed to identify the miRNAs differentially expressed between relapsed and non-relapsed patient samples, which were validated in the expansion set, by qRT-PCR. RT2 Profiler PCR Array was used for the screening of let-7e targets. Expression levels were correlated with relapse-free survival and overall survival. In the discovery set, 39 miRNAs were significantly deregulated, let-7e and miR-550 being the most underexpressed and overexpressed miRNAs in the relapsed group, respectively. In the expansion set, the underexpression of let-7e or the overexpression of 4 of its target genes (ACVR1B, CASP3, COL3A1, and COL5A2) were statistically associated with worse relapse-free survival. The expression of let-7e and 4 of its target genes are potential prognostic biomarkers in high-risk localized intestinal GIST. The expression of these genes is a potential molecular tool useful for a more accurate prognosis in this subset of GIST patients.

Exosomal non‑coding RNAs: Novel biomarkers with emerging clinical applications in gastric cancer (Review)

Gastric cancer (GC) is one of the most common types of malignant tumor and it demonstrates high mortality rates. The majority of cases of GC are diagnosed at an advanced stage, which seriously endangers the health of the patient. Therefore, discovering a novel diagnostic method for GC is a current priority. Exosomes are 40 to 150-nm-diameter vesicles consisting of a lipid bilayer secreted by a variety of cells that exist in multiple different types of body fluids. Exosomes contain diverse types of active substances, including RNAs, proteins and lipids, and play important roles in tumor cell communication, metastasis and neovascularization, as well as tumor growth. Non-coding RNAs (ncRNAs) do not code proteins, and instead have roles in a variety of genetic mechanisms, such as regulating the structure, expression and stability of RNAs, and modulating the translation and function of proteins. In recent years, exosomal ncRNAs have become a novel focus in research. An increasing number of studies have demonstrated that exosomal ncRNAs can be used in the prediction and treatment of GC. The present review briefly discusses the role of exosomal ncRNAs as a potential biomarker, and summarizes important regulatory genes involved in the development and progression of GC.

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

METHODS

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

MicroRNA-122-5p inhibits cell proliferation, migration and invasion by targeting CCNG1 in pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is a lethal human malignancy, and previous researches support the contribution of microRNA (miRNA) to cancer progression. MiR-122-5p is reported to participate in the regulation of various cancers, while the function of miR-122-5p in PDAC remains unclear. In this study, we investigated the precise mechanism of miR-122-5p involved in PDAC pathogenesis.

Methods

The expression levels of miR-122-5p were detected in human PDAC tissues and cell lines by miRNA RT-PCR. The effects of miR-122-5p on cell proliferation were explored by MTT assays, colony formation assays and flow cytometry assays. The ability of migration and invasion was determined by transwell assays. Dual Luciferase reporter assay was performed to validate the direct interaction between miR-122-5p and its target gene. The related molecules of cell cycle, apoptosis and epithelial–mesenchymal transition (EMT) were examined with qRT-PCR and western blot. In addition, xenograft mouse models were applied to explore the effects of miR-122-5p in vivo.

Results

MiR-122-5p was underexpressed, while CCNG1 was highly expressed in PDAC tissues and cells. MiR-122-5p was negatively correlated with TNM stage, tumor size and lymph node metastasis in PDAC patients. Overexpression of miR-122-5p suppressed the proliferation, migration and invasion in vitro and inhibited tumorigenesis in vivo. Furthermore, CCNG1 was a direct target of miR-122-5p. Upregulated CCNG1 could partially reverse the effects caused by miR-122-5p. Moreover, miR-122-5p inhibited EMT through downregulation of CCNG1.

Conclusion

Overexpression of miR-122-5p could inhibit cell proliferation, migration, invasion, and EMT by downregulating CCNG1 in PDAC, suggesting a potential therapeutic target for PDAC.

Insight into the effects of microRNA-23a-3p on pancreatic cancer and its underlying molecular mechanism

Previous studies have demonstrated that microRNA (miR)-23a-3p plays a role as an oncogene that is involved in several different types of carcinoma. However, few studies investigated the association between miR-23a-3p and pancreatic cancer (PC). The aim of the present study was to elucidate the biological functions of miR-23a-3p in PC and to investigate its underlying molecular mechanisms. The expression of miR-23a-3p in PC and adjacent normal tissues was investigated using microarrays. In order to validate the outcomes of the microarray results, reverse transcription-quantitative (RT-q)PCR was used to determine the expression levels of miR-23a-3p in PC tissues and cell lines. Furthermore, functional analyses were conducted following miR-23a-3p inhibition and overexpression, in order to assess the proliferation, invasion and migration of PC cells. Bioinformatics analysis indicated transforming growth factor-β receptor type II (TGFBR2) as a potential direct target of miR-23a-3p. Western blotting was performed in order to determine the protein expression of TGFBR2 in PC cell lines. The findings from the microarray demonstrated upregulation of miR-23a-3p in PC compared with normal tissues. RT-qPCR revealed significantly higher levels of miR-23a-3p expression in PC compared with normal control tissues or cells. Furthermore, miR-23a-3p was demonstrated to promote the proliferation, invasion and migration of PC cells, which was suppressed by the inhibition of miR-23a-3p. In addition, the miR-23a-3p expression level was negatively associated with TGFBR2 expression. Overall, the present study demonstrated the tumor-promoting effects of miR-23a-3p in PC cells. Furthermore, miR-23a-3p is a potential oncogenic regulator of PC, by targeting TGFBR2, and a biomarker or target for molecular therapy.

Assessment of a Urinary Kidney MicroRNA Panel as Potential Nephron Segment-Specific Biomarkers of Subacute Renal Toxicity in Preclinical Rat Models

Drug-induced kidney injury (DIKI) remains a significant concern during drug development. Whereas FDA-endorsed urinary protein biomarkers encounter limitations including the lack of translatability, there is a considerable interest surrounding the application of microRNAs (miRNAs) in the renal biomarker space. Current knowledge about the value of these novel biomarkers for subacute preclinical rodent studies is still sparse. In this work, Wistar rats were treated with three nephrotoxic compounds-cisplatin (CIS, proximal tubule, 2.5 mg/kg, intraperitoneal [i.p.]), puromycin (PUR, glomerulus, 20/10 mg/kg, i.p.) and N-phenylanthranylic acid (NPAA, collecting ducts, 500 mg/kg, per os)-for up to 28 days to evaluate the performance of a panel of 68 urinary miRNAs as potential nephron segment-specific biomarkers. Out of these 68 kidney injury associated-miRNAs, our selection strategy ultimately revealed rno-miR-34c-5p significantly dysregulated after CIS single administration, and rno-miR-335 and rno-miR-155-5p significantly dysregulated after PUR treatment. In contrast, NPAA daily administration strongly altered the expression profile of 28 miRNAs, with rno-miR-210-3p displaying the most robust changes. A thorough evaluation showed that these miRNA candidates could complement urinary protein biomarkers to detect CIS- or PUR-induced kidney injury in a subacute setting, with a mechanistic (based on rno-miR-34c-5p) and/or a kidney injury detection potential. Our results also provide the first evidence that urinary miRNAs could enhance the detection of collecting duct damage. Overall, these data improve our understanding of the utility of urinary miRNAs as DIKI biomarkers in a subacute DIKI preclinical setting and support the value of using urinary biomarker panels comprising proteins and miRNAs.

MicroRNA in Pancreatic Cancer: From Biology to Therapeutic Potential

Pancreatic cancer is one of the most aggressive malignancies, accounting for more than 45,750 deaths annually in the U.S. alone. The aggressive nature and late diagnosis of pancreatic cancer, coupled with the limitations of existing chemotherapy, present the pressing need for the development of novel therapeutic strategies. Recent reports have demonstrated a critical role of microRNAs (miRNAs) in the initiation, progression, and metastasis of cancer. Furthermore, aberrant expressions of miRNAs have often been associated with the cause and consequence of pancreatic cancer, emphasizing the possible use of miRNAs in the effective management of pancreatic cancer patients. In this review, we provide a brief overview of miRNA biogenesis and its role in fundamental cellular process and miRNA studies in pancreatic cancer patients and animal models. Subsequent sections narrate the role of miRNA in, (i) cell cycle and proliferation; (ii) apoptosis; (iii) invasions and metastasis; and (iv) various cellular signaling pathways. We also describe the role of miRNA's in pancreatic cancer; (i) diagnosis; (ii) prognosis and (iii) therapeutic intervention. Conclusion section describes the gist of review with future directions.

Downregulation of miR-21 inhibits the malignant phenotype of pancreatic cancer cells by targeting VHL

Background

MicroRNA (miR)-21 is overexpressed in numerous types of malignancy and participates in the development of cancer. However, the basic mechanism of the influence of miR-21 on the malignant phenotype of pancreatic cancer remains unclear.

Purpose

The present study aimed to investigate the role of miR-21 in pancreatic cancer development and explore its molecular mechanism.

Patients and methods

The tissue samples were collected at the Second Hospital of Tianjin Medical University (Tianjin, China) between January 2013 and December 2015. The expression of VHL in tissue samples was evaluated by IHC staining. The expression of miR-21 was measured by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-21 target gene was detected by real-time PCR, Western blot and the luciferase reporter assay. Cell viability, cell proliferation, cell migration and invasion were evaluated by the MTT assays, the colony formation assays and the transwell assays. The nude mouse tumor xenograft model was performed to detect the effect of miR-21 on tumor growth in vivo.

Results

Von Hippel-Lindau tumor suppressor (VHL) was downregulated in pancreatic cancer tissues compared with pancreatic non-tumor tissues. VHL was identified as a novel direct target of miR-21, by which it is negatively regulated. In PANC-1 cells, inhibition of miR-21 and upregulation of VHL significantly suppressed cell proliferation, migration and invasion. Knockdown of miR-21 inhibited the hypoxia-inducible factor (HIF)-1α/vascular endothelial growth factor (VEGF) pathway, while inhibiting the expression of matrix metallopeptidase (MMP)-2 and MMP-9. Silencing of miR-21 inhibited tumor growth in vivo.

Conclusion

Knockdown miR-21 increased the expression of VHL, and thus modulated the HIF-1α/VEGF pathway and the expression of MMP-2 and MMP-9, which led to the inhibition of the proliferation, migration and invasion of pancreatic cancer cells. All of these results suggest that the miR-21/VHL interaction may be a novel potential target for pancreatic cancer prevention and therapy.

Clinical and Molecular Analysis of Pathologic Fracture-associated Osteosarcoma: MicroRNA profile Is Different and Correlates with Prognosis

BACKGROUND

MicroRNAs are small, noncoding RNAs that regulate the expression of posttranslational genes. The presence of some specific microRNAs has been associated with increased risk of both local recurrence and metastasis and worse survival in patients with osteosarcoma. Pathologic fractures in osteosarcoma are considered to be more the manifestation of a neoplasm with a more aggressive biological behavior than the cause itself of worse prognosis. However, this has not been proved at the biological or molecular level. Currently, there has not been a microRNA profiling study of patients who have osteosarcoma with and without pathologic fractures that has described differences in terms of microRNA profiling between these two groups and their correlation with biologic behavior.

QUESTIONS/PURPOSES

(1) In patients with osteosarcoma of the extremities, how do the microRNA profiles of those with and without pathologic fractures compare? (2) What relationship do microRNAs have with local recurrence, risk of metastasis, disease-specific survival, and overall survival in osteosarcoma patients with pathologic fractures?

METHODS

Between 1994 and 2013, 217 patients were diagnosed and treated at our institution for osteosarcoma of the extremities. Patients were excluded if (1) they underwent oncologic resection of the osteosarcoma at an outside institution (two patients) or (2) they were diagnosed with an extraskeletal osteosarcoma (29 patients) or (3) they had less than 1 year of clinical follow-up and no oncologic outcome (local recurrence, metastasis, or death) (four patients). A total of 182 patients were eligible. Of those, 143 were high-grade osteosarcomas. After evaluation of tumor samples before chemotherapy treatment, a total of 80 consecutive samples were selected for sequencing. Demographic and clinical comparison between the sequenced and non-sequenced patients did not demonstrate any differences, confirming that both groups were comparable. Diagnostic samples from the extremities of 80 patients with high-grade extremity osteosarcomas who had not yet received chemotherapy underwent microRNA sequencing for an ongoing large-scale osteosarcoma genome profiling project at our institution. Six samples were removed after a second look by a musculoskeletal pathologist who verified cellularity and quality of samples to be sequenced, leaving a total of 74 patients. Of these, two samples were removed as they were confirmed to be pelvic tumors in a second check after sequencing. The final study sample was 72 patients (11 patients with pathologic fractures and 61 without). Sequencing data were correlated with fractures and local recurrence, risk of metastasis, disease-specific survival, and overall survival through Kaplan-Meier analyses.

RESULTS

Several microRNAs were expressed differently between the two groups. Among the markers with the highest differential expression (edgeR and DESeq algorithms), Hsa-mIR 656-3p, hsa-miR 493-5p, and hsa-miR 381-3p were upregulated in patients with pathologic fractures, whereas hsa-miR 363, hsa-miR 885-5p, and has-miR 20b-5p were downregulated. The highest differential expression fracture and nonfracture-associated microRNA markers also distinguished groups of patients with different metastasis risk, a well as different disease-specific and overall survival. Furthermore, the profile of pathologic fractures demonstrated a higher differential expression for microRNA markers that were previously associated with a higher risk of metastasis and lower survival rates in patients with osteosarcoma.

CONCLUSIONS

In patients who have osteosarcoma, the microRNA profiles of those with pathologic fractures are different than of patients without pathologic fractures. The highest differential expression mircroRNA molecules in patients with pathologic fractures predict also higher risk of metastatic disease as well as worse disease-specific survival and overall survival. Furthermore, we found higher differential expression of microRNAs in the pathologic fracture group previously associated with poor prognosis. The higher risk of metastasis and poorer overall survival in patients with pathologic fractures is inherent to tumor aggressive biologic behavior. It is plausible that the fracture itself is not the direct cause of worse prognosis but another manifestation of tumor biologic aggressiveness. Identification of these molecules through liquid biopsies may help to determine which patients may benefit from surgery before fractures occur. The same technology can be applied to identify patterns of response to conventional chemotherapy, assisting in more specific and accurate systemic therapy.

LEVEL OF EVIDENCE LEVEL

III, prognostic study.

Let-7 as biomarker, prognostic indicator, and therapy for precision medicine in cancer

Abnormal regulation and expression of microRNAs (miRNAs) has been documented in various diseases including cancer. The miRNA let-7 (MIRLET7) family controls developmental timing and differentiation. Let-7 loss contributes to carcinogenesis via an increase in its target oncogenes and stemness factors. Let-7 targets include genes regulating the cell cycle, cell signaling, and maintenance of differentiation. It is categorized as a tumor suppressor because it reduces cancer aggressiveness, chemoresistance, and radioresistance. However, in rare situations let-7 acts as an oncogene, increasing cancer migration, invasion, chemoresistance, and expression of genes associated with progression and metastasis. Here, we review let-7 function as tumor suppressor and oncogene, considering let-7 as a potential diagnostic and prognostic marker, and a therapeutic target for cancer treatment. We explain the complex regulation and function of different let-7 family members, pointing to abnormal processes involved in carcinogenesis. Let-7 is a promising option to complement conventional cancer therapy, but requires a tumor specific delivery method to avoid toxicity. While let-7 therapy is not yet established, we make the case that assessing its tumor presence is crucial when choosing therapy. Clinical data demonstrate that let-7 can be used as a biomarker for rational precision medicine decisions, resulting in improved patient survival.

Long noncoding RNA DIO3OS interacts with miR-122 to promote proliferation and invasion of pancreatic cancer cells through upregulating ALDOA

Background

Long noncoding RNA (lncRNA) has been implicated in numerous tumors, including pancreatic cancer (PC). However, the precise cellular roles and molecular mechanisms of lncRNA DIO3OS on PC development remains to be fully clarified.

Methods

We performed the meta-analysis on PC samples and non-tumor samples retrieved from the TCGA database, and measured the levels of DIO3OS in PC cell lines and a normal pancreatic duct epithelial cell line HPDE6-C7. Cell proliferation was evaluated via CCK-8 assay. Cell invasion in vitro was investigated by transwell assay. The RNA immunoprecipitation assay and luciferase reporter assay was utilized to confirm the putative miR-122-binding site in DIO3OS. The effects of DIO3OS on PC progression were tested using in vivo subcutaneous xenografts.

Results

Our results showed that DIO3OS was highly expressed in human PC tissues and PC cell lines. DIO3OS exhibited oncogenic properties in stimulating PC cell proliferation and invasion in vitro and promoting cancer growth in vivo. Through online predictive tools and functional experiments, we found that DIO3OS could bind directly to microRNA-122 (miR-122) and inhibited its expression, which functioned as a tumor suppressor in PC cells. We also verified that ALDOA was the direct target of miR-122, and the tumor suppressive effects caused by DIO3OS knockdown or miR-122 overexpression could be rescued by re-expression of ALDOA in PC cells.

Conclusions

Overall, our study suggested that lncRNA DIO3OS promotes PC cell growth and invasion by competing for miR-122 to modulate the expression of ALDOA. These findings yield a better understanding of the potential mechanisms by which gain of DIO3OS expression accelerates PC progression.

MicroRNAs as Potential Biomarkers for Chemoresistance in Adenocarcinomas of the Esophagogastric Junction

Concerning adenocarcinomas of the esophagogastric junction, neoadjuvant chemotherapy is regularly implemented, but patients' response varies greatly, with some cases showing no therapeutic effect, being deemed as chemoresistant. Small, noncoding RNAs (miRNAs) have evolved as key players in biological processes, including malignant diseases, often promoting tumor growth and expansion. In addition, specific miRNAs have been implicated in the development of chemoresistance through evasion of apoptosis, cell cycle alterations, and drug target modification. We performed a retrospective study of 33 patients receiving neoadjuvant chemotherapy by measuring their miRNA expression profiles. Histologic tumor regression was evaluated using resection specimens, while miRNA profiles were prepared using preoperative biopsies without prior therapy. A preselected panel of 96 miRNAs, known to be of importance in various malignancies, was used to test for significant differences between responsive (chemosensitive) and nonresponsive (chemoresistant) cases. The cohort consisted of 12 nonresponsive and 21 responsive cases with the following 4 miRNAs differentially expressed between both the groups: hsa-let-7f-5p, hsa-miRNA-221-3p, hsa-miRNA-31-5p, and hsa-miRNA-191-5p. The former 3 showed upregulation in chemoresistant cases, while the latter showed upregulation in chemosensitive cases. In addition, significant correlation between high expression of hsa-miRNA-194-5p and prolonged survival could be demonstrated (p value <0.0001). In conclusion, we identified a panel of 3 miRNAs predicting chemoresistance and a single miRNA contributing to chemosensitivity. These miRNAs might function as prognostic biomarkers and enable clinicians to better predict the effect of one or more reliably select patients benefitting from (neoadjuvant) chemotherapy.

Noncoding RNAs in cancer therapy resistance and targeted drug development

Noncoding RNAs (ncRNAs) represent a large segment of the human transcriptome and have been shown to play important roles in cellular physiology and disease pathogenesis. Increasing evidence on the functional roles of ncRNAs in cancer progression emphasizes the potential of ncRNAs for cancer treatment. Here, we summarize the roles of ncRNAs in disease relapse and resistance to current standard chemotherapy and radiotherapy; the current research progress on ncRNAs for clinical and/or potential translational applications, including the identification of ncRNAs as therapeutic targets; therapeutic approaches for ncRNA targeting; and ncRNA delivery strategies in potential clinical translation. Several ongoing clinical trials of novel RNA-based therapeutics were also emphasized. Finally, we discussed the perspectives and obstacles to different target combinations, delivery strategies, and system designs for ncRNA application. The next approved nucleic acid drug to treat cancer patients may realistically be on the horizon.

Clinical value of miRNA-122 in the diagnosis and prognosis of various types of cancer

The present study aimed to systematically analyze the value of microRNA-122 (miRNA-122) in the diagnosis and prognosis of hepatocellular carcinoma (HCC) and other types of cancer. First, the reverse transcription-quantitative polymerase chain reaction method was used to detect the expression levels of miRNA-122 in the serum samples of patients with HCC, benign lesions and healthy volunteers. Next, miRNA-seq data of miRNA-122 from The Cancer Genome Atlas database were used to analyze the differential expression and overall survival rate associated with a variety of types of cancer. Meanwhile, the target gene prediction of miRNA-122 was performed using four different software programs. Finally, 353 significant target genes were identified for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis. Finally, it was demonstrated that the expression levels of miRNA-122 in the HCC group were increased compared with the healthy group (P<0.001), but decreased with respect to the benign group (P<0.001). In addition, the combination of the miRNA-122 and a fetoprotein may further improve the diagnostic accuracy between the HCC and healthy groups (area under the curve, 0.980; 95% confidence interval, 0.958–1.000). It was also demonstrated that miRNA-122 exhibited significantly differential expression and the overall survival rate was predicted for various other types of cancer, including colorectal cancer, renal carcinoma, cholangiocarcinoma, prostate cancer and thyroid carcinoma. Functional enrichment analysis demonstrated that the target genes of miRNA-122 may contribute to the composition of the nucleus and cytoplasm, and regulate a variety of biological processes, including cardiac muscle cell differentiation and glucose metabolic processes via protein biosynthesis, estrogen and glucagon associated signaling pathways. These results revealed that miRNA-122 may be an indispensable biomarker for the diagnosis, prognostic evaluation and targeted therapy in pan-cancer.

Dysregulation of key microRNAs in pancreatic cancer development

Pancreatic cancer (PC) is mentioned as one of the fourth major cause of cancer-related deaths and also is considered as one of the most malignancies worldwide. Sadly, widely metastasis is frequently observed at the time of PC detection and there are, thereby, almost poor prognosis and ineffective treatment in PC patients. microRNAs (miRNAs), a group of short non-coding RNAs, regulate various cellular and developmental mechanisms, such as cell growth, proliferation, apoptosis, differentiation and angiogenesis. Also, they have essential roles even on the progression of different human and animal diseases. In recent years, extensive studies confirmed the important role of miRNAs in various steps of PC developments, including; tumor initiation, invasion and metastasis, which can use valuably for cancer detection, prognosis and therapy. Therefore, the present study reviewed the new recent investigations in miRNAs involvement in the biology of PC associated with their clinical implications.

The Combination of MiRNA-196b, LCN2, and TIMP1 is a Potential Set of Circulating Biomarkers for Screening Individuals at Risk for Familial Pancreatic Cancer

Individuals at risk (IAR) of familial pancreatic cancer (FPC) are good candidates for screening. Unfortunately, neither reliable imaging modalities nor biomarkers are available to detect high-grade precursor lesions or early cancer. Circulating levels of candidate biomarkers LCN2, TIMP1, Glypican-1, RNU2-1f, and miRNA-196b were analyzed in 218 individuals with sporadic pancreatic ductal adenocarcinoma (PDAC, n = 50), FPC (n = 20), chronic pancreatitis (n = 10), IAR with relevant precursor lesions (n = 11) or non-relevant lesions (n = 5), 20 controls, and IAR with (n = 51) or without (n = 51) lesions on pancreatic imaging. In addition, corresponding duodenal juice samples were analyzed for Glypican-1 (n = 144) enrichment and KRAS mutations (n = 123). The panel miR-196b/LCN2/TIMP1 could distinguish high-grade lesions and stage I PDAC from controls with absolute specificity and sensitivity. In contrast, Glypican-1 enrichment in serum exosomes and duodenal juice was not diagnostic. KRAS mutations in duodenal juice were detected in 9 of 12 patients with PDAC and only 4 of 9 IAR with relevant precursor lesions. IAR with lesions on imaging had elevated miR-196b/LCN2/TIMP1 levels (p = 0.0007) and KRAS mutations in duodenal juice (p = 0.0004) significantly more often than IAR without imaging lesions. The combination miR-196b/LCN2/TIMP1 might be a promising biomarker set for the detection of high-grade PDAC precursor lesions in IAR of FPC families.

Clinical Impact of Epithelial-to-Mesenchymal Transition Regulating MicroRNAs in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive carcinoma entities worldwide with early and rapid dissemination. Recently, we discussed the role of microRNAs as epigenetic regulators of Epithelial-to-Mesenchymal Transition (EMT) in PDAC. In this study, we investigated their value as diagnostic and prognostic markers in tissue and blood samples of 185 patients including PDAC, non-malignant pancreatic disorders, and age-matched healthy controls. Expression of the microRNA-200-family (microRNAs -141, -200a, -200b, -200c, -429) and microRNA-148a was significantly downregulated in tissue of PDAC Union internationale contre le cancer (UICC) Stage II. Correspondingly, stromal PDAC tissue showed strong expression of Fibronectin, Vimentin, and ZEB-1 (Zinc finger E-box-binding homeobox) versus low expression of E-cadherin. Transient transfection of microRNA-200b and microRNA-200c mimics resulted in the downregulation of their key target ZEB-1. Inversely, blood serum analyses of patients with PDAC UICC Stages II, III, and IV showed a significant over-expression of microRNA-200-family members, microRNA-148a, microRNA-10b, and microRNA-34a. Correspondingly, Enzyme-linked Immunosorbent Assay (ELISA) analyses revealed a significant over-expression of soluble E-cadherin in serum samples of PDAC patients versus healthy controls. The best diagnostic accuracy to distinguish between PDAC and non-PDAC in this patient collective could be achieved in tissue by microRNA-148a with an area under the receiver-operating-characteristic (ROC) curve (AUC) of 0.885 and in blood serum by a panel of microRNA-141, -200b, -200c, and CA.19-9 with an AUC of 0.890. Both diagnostic tools outreach the diagnostic performance of the currently most common diagnostic biomarker CA.19-9 (AUC of 0.834). Kaplan Meier survival analysis of this patient collective revealed an improved overall survival in PDAC patients with high expression of tissue-related microRNA-34a, -141, -200b, -200c, and -429. In conclusion, EMT-regulating microRNAs have great potential as liquid and solid biopsy markers in PDAC patients. Their prognostic and therapeutic benefits remain important tasks for future studies.

Plasma miRNAs in diagnosis and prognosis of pancreatic cancer: A miRNA expression analysis

The differential expression of microRNAs (miRNAs) in plasma of pancreatic cancer (PC) patients may act as a diagnostic biomarker. A four-stage study was performed to identify plasma miRNAs with potential in detecting PC. Exiqon panels (20 PC vs. 10 normal controls (NCs)) were applied in the screening phase to obtain miRNA profiling. The identified miRNAs were further assessed in the training (40 PC vs. 40 NCs) and testing stages (112 PC vs. 116 NCs) with qRT-PCR assays. A six-miRNA signature including up-regulated miR-122-5p, miR-125b-5p, miR-192-5p, miR-193b-3p, miR-221-3p and miR-27b-3p was identified. The signature could accurately discriminate PC patients from NCs with areas under the receiver operating characteristic curve of 0.848, 0.833 and 0.937 for the training, testing and the external validation stage (41 PC vs. 50 NCs), respectively. The multivariate Cox regression analyses showed that down-regulated plasma miR-125b-5p could predict worse OS independent from late tumor stage and high CA19-9. All the six miRNAs except miR-122-5p showed high expression levels in PC tissues than those in matched normal tissues. MiR-122-5p and miR-193b-3p were up-regulated, while miR-221-3p was down-regulated in plasma exosomes from PC patients. Bioinformatics analysis demonstrated that the miRNAs might involve in several molecular pathways closely related with PC such as p53 signaling pathway, pancreatic cancer, TGF-beta signaling pathway and so on. In conclusion, we identified a six-miRNA signature in plasma which could act as a non-invasive biomarker in diagnosis and prognosis of PC. Plasma miR-125b-5p might act as an independent biomarker in predicting OS of PC patients.

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

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

Hsa-miR-202-3p, up-regulated in type 1 gastric neuroendocrine neoplasms, may target DUSP1

AIM

To detect abnormal microRNA (miRNA) expression in type 1 gastric neuroendocrine neoplasms (g-NENs) and find potential target genes.

METHODS

Tumour tissues from patients with type 1 g-NENs were used as experimental samples, and gastric mucosal tissues from the same patients obtained during gastroscopy review after several months were used as control samples. miRNA expression was examined with Agilent human miRNA chips and validated via RT-PCR. Three types of target gene prediction software (TargetScan, PITA, and microRNAorg) were used to predict potential target genes of the differentially expressed miRNAs, and a dual-luciferase reporter assay system was used for verification.

RESULTS

Six miRNAs were significantly upregulated or downregulated in the tumours compared to the control samples. Among them, miR-202-3p was extraordinarily upregulated. RT-PCR of seven sample sets confirmed that miR-202-3p was upregulated in tumour tissues. In total, 215 target genes were predicted to be associated with miR-202-3p. Among them, dual-specificity phosphatase 1 (DUSP1) was reported to be closely related to tumour occurrence and development. The dual-luciferase reporter assay showed that miR-202-3p directly regulated DUSP1 in 293T cells.

CONCLUSION

miR-202-3p is upregulated in type 1 g-NEN lesions and might play important roles in the pathogenesis of type 1 g-NENs by targeting DUSP1.

Overexpression of the Long Noncoding RNA HomeoboxA Transcript at the Distal Tip Predicts Poor Prognosis in a KRAS-Independent Manner in Periampullary Region Tumors

OBJECTIVES

Periampullary region tumors (PRTs) are the fifth highest cause of cancer-related deaths worldwide. Although recent studies have highlighted the prognostic value of the long noncoding RNA HomeoboxA transcript at the distal tip (HOTTIP) in patients with pancreatic ductal adenocarcinoma, the relationship between HOTTIP and clinical outcome of all PRTs remains obscure. The aim of this study was to clarify the prognostic significance of HOTTIP in patients with all PRTs related to KRAS mutational status.

METHODS

HomeoboxA transcript at the distal tip expression was detected in 100 PRT samples using quantitative real-time polymerase chain reaction. The associations between HOTTIP levels, clinicopathological factors, and patient prognosis were also analyzed.

RESULTS

The expression of HOTTIP was found to be significantly upregulated by 32-fold (P = 0.031) in tumor tissues compared with normal tissues. The over expression of HOTTIP was related with presence of invasion and metastasis (P = 0.0467, P = 0.0256). In addition, increased HOTTIP expression was associated with poor prognosis independent of KRAS mutation (P < 0.001; n = 72). Moreover, multivariate analysis showed that high HOTTIP expression was an unfavorable prognostic factor for overall survival.

CONCLUSIONS

Our findings indicate that high levels of HOTTIP expression have the potential to be an independent, unfavorable prognostic factor for patients with PRT.

Trehalose significantly enhances the recovery of serum and serum exosomal miRNA from a paper-based matrix

The preservation of nucleic acids from clinical samples is critical to facilitate accurate molecular diagnosis. The use of a paper matrix, Flinders Technology Associates (FTA) Elute cards, to archive DNA and viral RNA is well-documented. However, the feasibility of FTA Elute cards for archiving serum and serum exosomal microRNAs (miRNAs) remains unclear. Here, we performed a comprehensive evaluation of FTA Elute cards for miRNA storage and recovery in different pre-analytical conditions. The recovery of serum miRNA dry-spotted on FTA Elute cards by direct elution with water at high temperature was poor. However, serum miRNAs dry-spotted on the cards were isolated with about 40% yield when using QIAzol lysis reagent and recovery was improved remarkably (>80%) upon extraction from cards pre-treated with trehalose. miRNAs stored on the cards remained stable at room temperature and can be kept for prolonged periods. Furthermore, miRNAs could be similarly recovered from serum exosomes dry-spotted on the cards. Importantly, when using sera from gastric cancer (GC) patients, the miRNAs were efficiently recovered from trehalose pre-treated cards without affecting their representation. Collectively, we have demonstrated the potential of FTA Elute cards to archive serum and serum exosomal miRNAs, making it useful for biomarker discovery and diagnostics.

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.

microRNAs Make the Call in Cancer Personalized Medicine

Since their discovery and the advent of RNA interference, microRNAs have drawn enormous attention because of their ubiquitous involvement in cellular pathways from life to death, from metabolism to communication. It is also widely accepted that they possess an undeniable role in cancer both as tumor suppressors and tumor promoters modulating cell proliferation and migration, epithelial-mesenchymal transition and tumor cell invasion and metastasis. Moreover, microRNAs can even affect the tumor surrounding environment influencing angiogenesis and immune system activation and recruitment. The tight association of microRNAs with several cancer-related processes makes them undoubtedly connected to the effect of specific cancer drugs inducing either resistance or sensitization. In this context, personalized medicine through microRNAs arose recently with the discovery of single nucleotide polymorphisms in the target binding sites, in the sequence of the microRNA itself or in microRNA biogenesis related genes, increasing risk, susceptibility and progression of multiple types of cancer in different sets of the population. The depicted scenario implies that the overall variation displayed by these small non-coding RNAs have an impact on patient-specific pharmacokinetics and pharmacodynamics of cancer drugs, pushing on a rising need of personalized treatment. Indeed, microRNAs from either tissues or liquid biopsies are also extensively studied as valuable biomarkers for disease early recognition, progression and prognosis. Despite microRNAs being intensively studied in recent years, a comprehensive review describing these topics all in one is missing. Here we report an up-to-date and critical summary of microRNAs as tools for better understanding personalized cancer biogenesis, evolution, diagnosis and treatment.

EMT and Treatment Resistance in Pancreatic Cancer

Pancreatic cancer (PC) is the third leading cause of adult cancer mortality in the United States. The poor prognosis for patients with PC is mainly due to its aggressive course, the limited efficacy of active systemic treatments, and a metastatic behavior, demonstrated throughout the evolution of the disease. On average, 80% of patients with PC are diagnosed with metastatic disease, and the half of those who undergo surgery and adjuvant therapy develop liver metastasis within two years. Metastatic dissemination is an early event in PC and is mainly attributed to an evolutionary biological process called epithelial-to-mesenchymal transition (EMT). This innate mechanism could have a dual role during embryonic growth and organ differentiation, and in cancer progression, cancer stem cell intravasation, and metastasis settlement. Many of the molecular pathways decisive in EMT progression have been already unraveled, but little is known about the causes behind the induction of this mechanism. EMT is one of the most distinctive and critical features of PC, occurring even in the very first stages of tumor development. This is known as pancreatic intraepithelial neoplasia (PanIN) and leads to early dissemination, drug resistance, and unfavorable prognosis and survival. The intention of this review is to shed new light on the critical role assumed by EMT during PC progression, with a particular focus on its role in PC resistance.

MicroRNA-21 as a prognostic biomarker in patients with pancreatic cancer - A systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to summarize the current knowledge regarding microRNA-21 and to evaluate its prognostic impact in patients with pancreatic cancer.

METHODS

We conducted an electronic literature search to identify all published studies in PubMed/MEDLINE, Scopus and Google Scholar databases from 2000 until August 2016.

RESULTS

A total of 17 studies involving 1471 patients met the inclusion criteria for the quantitative synthesis. The microRNA-21 upregulation was significantly associated with poorer overall survival, disease-free survival, and progression-free survival. The subgroup analysis revealed that microRNA-21 overexpression has a significant higher prognostic value for patients who receive adjuvant chemotherapy. Increased microRNA-21 was associated with a statistically significant higher rate of metastatic lymph nodes and poorly differentiated tumors.

CONCLUSIONS

MicroRNA-21 upregulation in pancreatic cancer is associated with a significantly poorer overall survival, disease-free survival, and progression-free survival. MicroRNA-21 may be a useful prognostic biomarker, allowing stratification for chemotherapy administration, and being a component of precision medicine in patients with pancreatic cancer.