MicroRNA profiling of diagnostic needle aspirates from patients with pancreatic cancer

Decreased miR-451a in cerebrospinal fluid, a marker for both cognitive impairment and depressive symptoms in Alzheimer's disease

Background: Alzheimer's disease (AD) patients are often accompanied by depressive symptoms, but its underlying mechanism remains unclear. The present study aimed to explore the potential role of microRNAs in the comorbidity of AD and depression. Methods: The miRNAs associated with AD and depression were screened from databases and literature and then confirmed in the cerebrospinal fluid (CSF) of AD patients and different ages of transgenic APP/PS1 mice. AAV9-miR-451a-GFP was injected into the medial prefrontal cortex (mPFC) of APP/PS1 mice at seven months, and four weeks later, a series of behavioral and pathological analyses were performed. Results: AD patients had low CSF levels of miR-451a, which was positively correlated with the cognitive assessment score, but negatively with their depression scale. In the mPFC of APP/PS1 transgenic mice, the miR-451a levels also decreased significantly in the neurons and microglia. Specific virus vector-induced overexpression of miR-451a in the mPFC of APP/PS1 mice ameliorated AD-related behavior deficits and pathologies, including long-term memory defects, depression-like phenotype, β-amyloid load, and neuroinflammation. Mechanistically, miR-451a decreased the expression of neuronal β-secretase 1 of neurons through inhibiting Toll-like receptor 4/Inhibitor of kappa B Kinase β/ Nuclear factor kappa-B signaling pathway and microglial activation by inhibiting activation of NOD-like receptor protein 3, respectively. Conclusion: This finding highlighted miR-451a as a potential target for diagnosing and treating AD, especially for those with coexisting symptoms of depression.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Pancreatic Cancer: Genetic Conditions and Epigenetic Alterations

BACKGROUND

Pancreatic cancer is a lethal proliferative disease driven by multiple genetic and epigenetic alterations. Microarrays and omics-based sequencing techniques are potent tools that have facilitated a broader understanding of the complex biological processes that drive pancreatic ductal adenocarcinoma (PDAC). In turn, these tools have resulted in the identification of novel disease markers, prognostic factors, and therapeutic targets. Herein, we provide a review of the genetic and epigenetic drivers of PDAC relative to recent discoveries that impact patient management.

METHODS

A review of PubMed, Medline, Clinical Key, and Index Medicus was conducted to identify literature from January 1995 to July 2022 that is related to PDAC genetics and epigenetics. Articles in Spanish and English were considered during selection.

RESULTS

Molecular, genetic, and epigenetic diagnostic tools, novel biomarkers, and promising therapeutic targets have emerged in the treatment of pancreatic cancer. The implementation of microarray technology and application of large omics-based data repositories have facilitated recent discoveries in PDAC. Multiple molecular analyses based on RNA interference have been instrumental in the identification of novel therapeutic targets for patients with PDAC. Moreover, microarrays and next-generation omics-based discoveries have been instrumental in the characterization of subtypes of pancreatic cancer, thereby improving prognostication and refining patient selection for available targeted therapies.

CONCLUSION

Advances in molecular biology, genetics, and epigenetics have ushered in a new era of discovery in the pathobiology of PDAC. Current efforts are underway to translate these findings into clinical tools and therapies to improve outcomes in patients with PDAC.

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

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

Influence of Micro-RNA-423 Gene Variation on Risk and Characteristics of Breast Cancer

BACKGROUND

Micro-RNAs (miRNAs) are post-transcriptional regulators of gene expression that are abundantly expressed in a variety of cancers, including breast cancer. The mechanism of miRNAs in breast cancer oncogenesis is poorly understood. The goal of this study was to determine if there was a link between the miR-423 rs6505162 gene variation and breast cancer susceptibility among Egyptian patients.

METHODS

This was a case control study that included 120 female patients with pathologically confirmed breast cancer and 120 healthy controls. The patients and controls were genotyped for miR-423 rs6505162 polymorphism by real time PCR. The association of breast cancer patients' genotypic variant and clinicopathological characteristics was analyzed.

RESULTS

Breast cancer patients showed significantly higher AA and CA genotypes frequencies when compared to controls. This was translated as higher risk to develop breast cancer in patients harboring these genotypic variants (OR = 3.28, p= 0.002; OR = 2.11, p= 0.011, respectively). The frequencies of Her2 positive and advanced stage disease were significantly increased in the AA genotype variant (p<0.001).

CONCLUSION

Our data suggest that miR-423 rs6505162 polymorphism could be a potential risk factor in the pathogenesis of breast cancer among Egyptian population.

The role of miR-200 family in the regulation of hallmarks of cancer

MiRNAs are short non-coding RNAs that regulate gene expression post-transcriptionally contributing to the development of different diseases including cancer. The miR-200 family consists of five members, miR-200a, miR-200b, miR-200c, miR-141, and miR-429. Their expression is dysregulated in cancer tissue and their level is altered in the body fluids of cancer patients. Moreover, the levels of miR-200 family members correlate with clinical parameters such as cancer patients' survival which makes them potentially useful as diagnostic and prognostic biomarkers. MiRNAs can act as either oncomiRs or tumor suppressor miRNAs depending on the target genes and their role in the regulation of key oncogenic signaling pathways. In most types of cancer, the miR-200 family acts as tumor suppressor miRNA and regulates all features of cancer. In this review, we summarized the expression pattern of the miR-200 family in different types of cancer and their potential utility as biomarkers. Moreover, we comprehensively described the role of miR-200 family members in the regulation of all hallmarks of cancer proposed by Hanahan and Weinberg with the focus on the epithelial-mesenchymal transition, invasiveness, and metastasis of tumor cells.

Diagnostic and prognostic value of microRNA-486 in patients with lung cancer: A systematic review and meta-analysis

PURPOSE

There are conflicting opinions on whether miR-486 could be used for cancer diagnosis and prognosis. Therefore, this present study investigated the potential effect of miR-486 on lung cancer diagnosis and prognosis.

METHODS

We researched PubMed, Embase, Wanfang and Chinese National Knowledge Infrastructure databases to select relevant publications. Specificity and sensitivity were obtained for the pooled and subgroup diagnostic meta-analysis while the hazard ratio was for prognostic meta-analysis. Publication analyses and sensitivity analyses were conducted to investigate possible sources of heterogeneity.

RESULTS

The overall sensitivity and specificity with 95% confidence intervals were 0.8 (0.8-0.9) and 0.9 (0.9-0.9). Results of subgroup analysis showed that high diagnostic efficacy might be obtained by miR-486 combined with other microRNAs (area under the curve (AUC): 0.9 (0.9-1.0)) to distinguish lung cancer patients from healthy controls (AUC: 1.0 (0.9-1.0)), especially for lung adenocarcinoma (AUC: 1.0 (1.0-1.0)) in the Asian population (AUC: 0.9 (0.9-1.0)). For prognosis prediction of miR-486 in overall non-small cell lung cancer, the overall hazard ratio with 95% confidence interval was 1.15 (0.85-1.54) for high versus low expression of miR-486, which indicated that a high miR-486 level was not related to the high risk of poor outcome. However, for the subgroup of progression-free survival and patients with chemotherapy, the hazard ratio was 0.41 (0.21-0.77), indicating that the higher miR-486 level would decrease the risk of poor progression-free survival for lung cancer patients with chemotherapy.

CONCLUSION

This study suggested circulating miR-486 combined with other microRNAs could be used as ideal biomarkers in early diagnosis and prognosis prediction for lung cancer, especially for lung adenocarcinoma in the Asian population.

The Role of microRNA Let-7d in Female Malignancies and Diseases of the Female Reproductive Tract

microRNAs are small noncoding RNAs that regulate gene expression at the posttranscriptional level. Let-7d is a microRNA of the conserved let-7 family that is dysregulated in female malignancies including breast cancer, ovarian cancer, endometrial cancer, and cervical cancer. Moreover, a dysregulation is observed in endometriosis and pregnancy-associated diseases such as preeclampsia and fetal growth restriction. Let-7d expression is regulated by cytokines and steroids, involving transcriptional regulation by OCT4, MYC and p53, as well as posttranscriptional regulation via LIN28 and ADAR. By downregulating a wide range of relevant mRNA targets, let-7d affects cellular processes that drive disease progression such as cell proliferation, apoptosis (resistance), angiogenesis and immune cell function. In an oncological context, let-7d has a tumor-suppressive function, although some of its functions are context-dependent. Notably, its expression is associated with improved therapeutic responses to chemotherapy in breast and ovarian cancer. Studies in mouse models have furthermore revealed important roles in uterine development and function, with implications for obstetric diseases. Apart from a possible utility as a diagnostic blood-based biomarker, pharmacological modulation of let-7d emerges as a promising therapeutic concept in a variety of female disease conditions.

microRNA-873 inhibits self-renewal and proliferation of pancreatic cancer stem cells through pleckstrin-2-dependent PI3K/AKT pathway

Recent studies have emphasized microRNAs (miRs) as crucial regulators in the occurrence and development of pancreatic cancer that continues to be one of the deadliest malignancies with few effective therapies. The study aimed to investigate the functional role of miR-873 and its associated mechanism to unravel the biological characteristics of pancreatic cancer stem cells in tumor growth. The expression patterns of pleckstrin-2 (PLEK2) and miR-873 were detected in the pancreatic cancer tissues. Then to further investigate specific role of miR-873, the pancreatic cancer stem cells were treated with miR-873 mimic, PLEK2, small interfering RNA against PLEK2, LY294002 (inhibitor of phosphatidylinositol 3-kinase/protein kinase B [PI3K/AKT] pathway) to detect the relative gene expression as well as their effects on cell self-renewal, proliferation and apoptosis. Finally, the tumor formation in nude mice was measured to verify the preceding results in vivo. Pancreatic cancer tissues exhibited a decline of miR-873 expression and an enhancement of PLEK2 expression. miR-873 targeted PLEK2 and downregulated its expression, leading to inhibition of PI3K/AKT pathway. Overexpressed miR-873 or silenced PLEK2 inhibited the self-renewal and proliferation while promoting the apoptosis of pancreatic cancer stem cells. Tumor formation was inhibited by overexpressed miR-873 or silenced PLEK2 in nude mice. Overall, miR-873 can suppress the self-renewal and proliferation of pancreatic cancer stem cells by blocking PLEK2-dependent PI3K/AKT pathway. Hence, this study contributes to understanding the role of miR-873 in pancreatic cancer stem cells and its underlying molecular mechanisms to aid in the development of effective pancreatic cancer therapeutics.

Potential diagnostic and therapeutic roles of exosomes in pancreatic cancer

Pancreatic cancer (PaCa) is considered an aggressive but still asymptomatic malignancy. Due to the lack of effective diagnostic markers, PaCa is often diagnosed during late metastatic stages. Besides surgical resection, no other treatment appears to be effective during earlier stages of the disease. Exosomes are related to a class of nanovesicles coated by a bilayer lipid membrane and enriched in protein, nucleic acid, and lipid contents. They are widely present in human body fluids, including blood, saliva, and pancreatic duct fluid, with functions in signal transduction and material transport. A large number of studies have suggested for a crucial role for exosomes in PaCa, which may be utilized to improve its future diagnosis and treatment, but the underlying molecular mechanisms as well as their potential clinical applications are largely unknown. By collecting and analyzing the most up-to-date literature, here we summarize the current progress of the clinical applications related to exosomes in PaCa. Therefore, we presently provide some rationale for the potential value of exosomes in PaCa, thereby promoting putative applications in targeted PaCa treatment.

Long non-coding RNA small nucleolar RNA host gene 6 aggravates pancreatic cancer through upregulation of far upstream element binding protein 1 by sponging microRNA-26a-5p

BACKGROUND

Pancreatic cancer (PC) is a highly deadly malignancy with few effective therapies. We aimed to unmask the role that long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) plays in PC cells by targeting far upstream element binding protein 1 (FUBP1) via microRNA-26a-5p (miR-26a-5p).

METHODS

SNHG6 expression was predicted by bioinformatics, followed by verification via reverse transcription quantitative polymerase chain reaction. Then, the interactions among SNHG6, miR-26a-5p, and FUBP1 were detected through online software analysis, dual luciferase reporter assay and RNA pull-down. After that, cells were treated with different small interfering RNAs and/or mimic to determine the interactions among SNHG6, miR-26a-5p, and FUBP1 and their roles in PC cells. Finally, the role of SNHG6 in tumor growth in vivo was evaluated by measuring the growth and weight of transplanted tumors in nude mice. A t-test, one-way and two-way analysis of variance were used for data analysis.

RESULTS

Compared with that in normal tissues, SNHG6 was highly expressed in PC tissues (1.00 ± 0.05 vs. 1.56 ± 0.06, t = 16.03, P < 0.001). Compared with that in human pancreatic duct epithelial cells (HPDE6-C7), SNHG6 showed the highest expression in PANC-1 cells (1.00 ± 0.06 vs. 3.87 ± 0.13, t = 34.72, P < 0.001) and the lowest expression in human pancreatic cancer cells (MIAPaCa-2) (1.00 ± 0.06 vs. 1.41 ± 0.07, t = 7.70, P = 0.0015). Compared with the levels in the si-negative control group, SNHG6 (0.97 ± 0.05 vs. 0.21 ± 0.06, t = 16.85, P < 0.001), N-cadherin (0.74 ± 0.05 vs. 0.41 ± 0.04, t = 8.93, P < 0.001), Vimentin (0.55 ± 0.04 vs. 0.25 ± 0.03, t = 10.39, P < 0.001), and β-catenin (0.62 ± 0.05 vs. 0.32 ± 0.03, t = 8.91, P < 0.001) were decreased, while E-cadherin (0.65 ± 0.06 vs. 1.36 ± 0.07, t = 13.34, P < 0.001) was increased after SNHG6 knockdown or miR-26a-5p overexpression, accompanied by inhibited cell proliferation, migration, and invasion. SNHG6 overexpression exerted the opposite effects. SNHG6 upregulated FUBP1 expression by sponging miR-26a-5p. Silencing SNHG6 blocked the growth of PC in vivo.

CONCLUSION

Silencing SNHG6 might ameliorate PC through inhibition of FUBP1 by sponging miR-26a-5p, thus providing further supporting evidence for its use in PC treatment.

Methylation-mediated miR-214 regulates proliferation and drug sensitivity of renal cell carcinoma cells through targeting LIVIN

LIVIN, a member of the inhibitor of apoptosis proteins (IAPs), is reported playing important roles in the development and progression of multiple human cancers. However, its underlined mechanisms in human renal cell carcinoma (RCC) are still needed to be clarified. In the present study, we reported that inhibition of miR‐214 promoted the expression of LIVIN, then facilitated RCC cells growth and reduced the sensitivity of RCC cells to chemotherapeutic drugs. In constant, overexpression of miR‐214 had contradictory effects. Further investigation showed that miR‐214 was down‐regulated in RCC because of abnormal methylation. In addition, DNA methyltransferase DNMT1, miR‐214 and LIVIN are directly correlated in RCC patients. In conclusion, these results suggest that abnormal miR‐214 methylation negatively regulates LIVIN, which may promote RCC cells growth and reduced the sensitivity of RCC cells to chemotherapeutic drugs.

Downregulation of miR-486-5p Enhances the Anti-Tumor Effect of 5-Fluorouracil on Pancreatic Cancer Cells

Background

5-Fluorouracil (5-Fu) has been applied to treat pancreatic cancer, which is one of the most common types of digestive system tumors. Evidence has shown that miR-486-5p could promote the proliferation of pancreatic cancer cells. Therefore, this study aimed to investigate whether downregulation of miR-486-5p could enhance the anti-tumor effect of 5-Fu on pancreatic cancer cells.

Methods

Cell Counting Kit 8 assay, flow cytometry and wound healing assays were used to detect proliferation, apoptosis and migration in PANC-1 cells. The expressions of Bcl-2, Bax, cleaved caspase 3, PTEN, p-Akt and p-ERK in PANC-1 cells were detected with Western blot assay.

Results

In this study, the inhibitory effects of 5-Fu on the proliferation, migration and invasion of PANC-1 cells were significantly enhanced following transfection with miR-486-5p antagonist. In addition, downregulation of miR-486-5p markedly enhanced the pro-apoptosis effect of 5-Fu on PANC-1 cells. Moreover, bioinformatics analysis and luciferase reporter assay identified that PTEN was the directly binding target of miR-486-5p. Meanwhile, downregulation of miR-486-5p markedly enhanced the anti-tumor effect of 5-Fu in PANC-1 cells via upregulation of the level of PTEN, and downregulation of the expressions of p-ERK and p-Akt. In vivo experiments confirmed that knockdown of miR-486-5p could enhance the anti-tumor effect of 5-Fu in PANC-1 xenograft model.

Conclusion

We found that the downregulation of miR-486-5p could enhance the anti-tumor effect of 5-Fu on pancreatic cancer cells. Therefore, miR-486-5p antagonist plus 5-Fu might be considered as a potential therapeutic strategy for the treatment of pancreatic cancer.

Salivary MicroRNA for Diagnosis of Cancer and Systemic Diseases: A Systematic Review

: Background: The aberrant expression of microRNAs (miRNAs) has been associated with several diseases, including cancer, inflammatory, and autoimmune conditions. Interest in salivary miRNAs as non-invasive tools for the diagnosis of malignancies and systemic diseases is rapidly increasing. The present systematic review was developed for answering the question: "Are salivary microRNAs reliable biomarkers for diagnosis of cancer and systemic diseases?"

METHODS

The application of inclusion and exclusion criteria led to the selection of 11 papers. Critical appraisals and quality assessments of the selected studies were performed through the National Institute of Health "Study Quality Assessment Tool" and the classification of the Oxford Center for Evidence-Based Medicine.

RESULTS

Seven studies reported statistically significant correlations between one or more salivary miRNAs and the investigated disease. The critical analysis allowed us to classify only two studies (18.2%) as having "good" quality, the rest being scored as "intermediate" (8; 73%) and "poor" (1; 9%). Evidence exists that salivary miR-940 and miR-3679-5p are reliable markers for pancreatic cancer and that miR140-5p and miR301a are promising molecules for the salivary diagnosis of gastric cancer.

CONCLUSIONS

Further studies, possibly avoiding the risk of bias highlighted here, are necessary to consolidate these findings and to identify new reliable salivary biomarkers.

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.

GALE Promotes the Proliferation and Migration of Glioblastoma Cells and Is Regulated by miR-let-7i-5p

Purpose

Glioma is the most common and lethal type of brain tumor. While GALE (UDP-galactose-4-epimerase) has been shown to be overexpressed in some kinds of cancers, its expression in gliomas has not been reported. MicroRNAs (miRNAs) function as tumor suppressors in many cancers, and online datasets can be used to predict whether GALE is regulated by miR-let-7i-5p. In this investigation, we explored the effect and regulatory mechanisms of GALE on glioblastoma growth via miR-let-7i-5p.

Methods

We used a Cox proportional hazards model and publicly available datasets to examine the relationship between GALE and the survival rates of glioma patients. Bioinformatics predicted the targeting of GALE by miR-let-7i-5p. The proliferation, migration, cell cycle and apoptosis of human glioblastoma cells were assessed by relevant assays. We also demonstrated the effect of GALE on glioblastoma multiforme [GBM] tumor growth using an in vivo orthotopic xenograft model.

Results

GALE was upregulated in human gliomas, especially in high-grade gliomas (e.g., GBM). An obvious decline in GALE expression was observed in human glioblastoma cell lines (U87 and U251) following treatment with a small interfering RNA (siRNA) targeting GALE or miR-let-7i-5p mimics. Knockdown of GALE or overexpression of miR-let-7i-5p (with miR-let-7i-5p mimics) inhibited U87 and U251 cell growth. miR-let-7i-5p significantly restrained the migration ability of human glioblastoma cells in vascular mimic (VM), wound healing and transwell assays, and GALE promoted glioblastoma growth in vivo.

Conclusion

Our findings confirm that GALE plays an important role in promoting the development of human glioma and that GALE can be regulated by miR-let-7i-5p to inhibit human glioblastoma growth.

Implications for cancer survivors

Our data show that cancer survivors have low GALE expression, which indicates that GALE may be a diagnostic biomarker and a promising therapeutic target in glioblastoma.

miR-451: A Novel Biomarker and Potential Therapeutic Target for Cancer

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded small RNAs involved in a variety of cellular processes, including ontogeny, cell proliferation, differentiation, and apoptosis. They can also function as oncogenes or tumor suppressor genes. Recent studies have revealed that miRNA-451 (miR-451) is involved in the regulation of various human physiological and pathological processes. Furthermore, it has been shown that miR-451 not only directly affects the biological functions of tumor cells but also indirectly affects tumor cell invasion and metastasis upon secretion into the tumor microenvironment via exosomes. Thus, miR-451 also influences the progression of tumorigenesis and drug resistance. This review summarizes the expression of miR-451 in various cancer types and the relationship between miR-451 and the diagnosis, treatment, and drug resistance of solid tumors. In addition, we address possible mechanisms of action of miR-451 and its potential application as a biomarker in the diagnosis and treatment of human cancers.

Comparison of tumour and serum specific microRNA changes dissecting their role in pancreatic ductal adenocarcinoma: a meta-analysis

Background

Pancreatic ductal adenocarcinoma (PDAC) is considered as one of the most aggressive cancers lacking efficient early detection biomarkers. Circulating miRNAs are now being considered to have potency to be used as diagnostic and prognostic biomarkers in different diseases as well as cancers. In case of cancer, a fraction of the circulating miRNAs is actually derived from the tumour tissue. This fraction would function as stable biomarker for the disease and also would contribute to the understanding of the disease development. There are not many studies exploring this aspect in pancreatic cancer and even there is not much overlap of results between existing studies.

Methods

In order to address that gap, we performed a miRNA microarray analysis to identify differentially expressed circulating miRNAs between PDAC patients and normal healthy individuals and also found two more similar datasets to perform a meta-analysis using a total of 182 PDAC patients and 170 normal, identifying a set of miRNAs significantly altered in patient serum. Next, we found five datasets studying miRNA expression profile in tumour tissues of PDAC patients as compared to normal pancreas and performed a second meta-analysis using data from a total of 183 pancreatic tumour and 47 normal pancreas to detect significantly deregulated miRNAs in pancreatic carcinoma. Comparison of these two lists and subsequent search for their target genes which were also deregulated in PDAC in inverse direction to miRNAs was done followed by investigation of their role in disease development.

Results

We identified 21 miRNAs altered in both pancreatic tumour tissue and serum. While deciphering the functions of their target genes, we characterized key miR-Gene interactions perturbing the biological pathways. We identified important cancer related pathways, pancreas specific pathways, AGE-RAGE signaling, prolactin signaling and insulin resistance signaling pathways among the most affected ones. We also reported the possible involvement of crucial transcription factors in the process.

Conclusions

Our study identified a unique meta-signature of 21 miRNAs capable of explaining pancreatic carcinogenesis and possibly holding the potential to act as biomarker for the disease detection which could be explored further.

Tumor penetrating nanomedicine targeting both an oncomiR and an oncogene in pancreatic cancer

Developing new targeted therapy for pancreatic cancer is one of the major current challenges in cancer research. KRAS mutations and miRNA dysregulation (e.g. miR-21-5p oncomiR) play key roles in Pancreatic Ductal Adenocarcinoma (PDAC), leading to rapid progression of the disease. As the KRAS mutation is a main driver of PDAC, anti-KRAS strategies remain a major therapeutic approach for PDAC treatment. Previously, utilization of either siKRAS or small chemically modified single-stranded RNA molecules that specifically disable miR-21 (anti-miR-21) were effective in slowing PDAC tumor growth in various tumor models when packaged in an innovative delivery system (TPN) required for efficient drug delivery to the PDAC tumor site. Here we have tested the utility of targeting the KRAS pathway through multiple mechanisms and via dual targeting of a PDAC oncomiR and oncogene. Initially we found that miR-217, which has been shown to directly regulate KRAS expression, is downregulated in our PDAC samples, thus we tested the benefits of anti-miR-21, miR-217 mimic or siKRAS loaded into the tumor-penetrating nanoparticles (TPN) that we had previously shown to potently target the largely impenetrable PDAC tumors, and found an enhanced anti-tumoral response upon dual treatments in KRAS-mutated PDAC models.

MicroRNAs hsa-miR-495-3p and hsa-miR-486-5p suppress basal and rifampicin-induced expression of human sulfotransferase 2A1 (SULT2A1) by facilitating mRNA degradation

Drug metabolizing enzymes mediate biotransformation of drugs and play an essential role in drug efficacy and toxicity. Human sulfotransferases are a superfamily of Phase II detoxification enzymes that metabolize a wide spectrum of endogenous compounds and xenobiotics. SULT2A1 is one of the most abundant hepatic sulfotransferases and it catalyzes the sulfate conjugation of many endogenous substrates, such as bile acids and steroids. In the current study, we utilized a systematic approach by combining a series of computational analyses and in vitro methods to identify miRNAs that repress SULT2A1 expression post-transcriptionally. Our in silico analyses predicted miRNA response elements for hsa-miR-495-3p and hsa-miR-486-5p within the 3'-UTR of SULT2A1 mRNA and the levels of these miRNAs were inversely correlated with that of SULT2A1 mRNA in human liver. Using fluorescence-based RNA electrophoretic mobility shift assays, we found that hsa-miR-495-3p and hsa-miR-486-5p interacted directly with the SULT2A1 3'-UTR. The activity of a luciferase reporter gene construct containing sequences from the SULT2A1 3-UTR was suppressed by hsa-miR-486-5p and hsa-miR-495-3p. Furthermore, gain- and loss-of-function assays demonstrated that hsa-miR-486-5p and hsa-miR-495-3p negatively modulate basal and rifampicin-induced expression of SULT2A1 in HepG2 cells by decreasing mRNA stability.

Ancillary Techniques in Cytologic Specimens Obtained from Solid Lesions of the Pancreas: A Review

Advanced methods of molecular characterization have elucidated the genetic, epigenetic, and proteomic alterations associated with the broad spectrum of pancreatic disease, particularly neoplasia. Next-generation sequencing, in particular, has revealed the genomic diversity among pancreatic ductal adenocarcinoma, neuroendocrine and acinar tumors, solid pseudopapillary neoplasm, and other pancreatico-biliary neoplasms. Differentiating these entities from one another by morphologic analysis alone may be challenging, especially when examining the small quantities of diagnostic material inherent to cytologic specimens. In order to enhance the sensitivity and specificity of pancreatic cytomorphology, multiple diagnostic, prognostic, and predictive ancillary tests have been and continue to be developed. Although a great number of such tests have been developed for evaluation of specimens collected from cystic lesions and strictures, ancillary techniques also play a significant role in the evaluation of cytologic specimens obtained from solid lesions of the pancreas. Furthermore, while some tests have been developed to differentiate diagnostic entities from one another, others have been developed to simply identify dysplasia and malignancy. Ancillary studies are particularly important in the subset of cases for which cytomorphologic analysis provides a result that is equivocal or insufficient to guide clinical management. Selection of appropriate ancillary testing modalities requires familiarity with both their methodology and the molecular basis of the pancreatic diseases for which testing is being performed.

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.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomal MicroRNA-126-3p Inhibits Pancreatic Cancer Development by Targeting ADAM9

Pancreatic cancer is a lethal malignancy with relatively few effective therapies. Recent investigations have highlighted the role of microRNAs (miRNAs) as crucial regulators in various tumor processes including tumor progression. Hence the current study aimed to investigate the role of bone marrow mesenchymal stem cell (BMSC)-derived exosomal microRNA-126-3p (miR-126-3p) in pancreatic cancer. Initially, miRNA candidates and related genes associated with pancreatic cancer were screened. PANC-1 cells were transfected with miR-126-3p or silenced a disintegrin and a metalloproteinase-9 (ADAM9) to examine their regulatory roles in pancreatic cancer cells. Additionally, exosomes derived from BMSCs were isolated and co-cultured with pancreatic cancer cells to elucidate the effects of exosomes in pancreatic cancer. Furthermore, the effects of overexpressed miR-126-3p derived from BMSCs exosomes on proliferation, migration, invasion, apoptosis, tumor growth, and metastasis of pancreatic cancer cells were analyzed in connection with lentiviral packaged miR-126-3p in vivo. Restored miR-126-3p was observed to suppress pancreatic cancer through downregulating ADAM9. Notably, overexpressed miR-126-3p derived from BMSCs exosomes inhibited the proliferation, invasion, and metastasis of pancreatic cancer cells, and promoted their apoptosis both in vitro and in vivo. Taken together, the key findings of the study indicated that overexpressed miR-126-3p derived from BMSCs exosomes inhibited the development of pancreatic cancer through the downregulation of ADAM9, highlighting the potential of miR-126-3p as a novel biomarker for pancreatic cancer treatment.

MiR-29b suppresses proliferation and mobility by targeting SOX12 and DNMT3b in pancreatic cancer

Pancreatic cancer is one of the leading causes of solid carcinoma with the worst survival rate. The reasons for the worst survival rate include the lack of biomarkers for early detection, diagnosis at a late stage, and the limitation of the current therapy. Further study to investigate the underlying molecular mechanism in pancreatic cancer patients is necessary. A previous study showed that the miR-29b expression level is dysregulated, suggesting that it may serve an important function in pancreatic cancer. The CCK8 assay and the colony formation assay were used to detect the proliferation ability of the treated pancreatic cancer cells; a wound-healing assay and a transwell assay were used to test the migration and invasion ability and the interactive action of miR-29b and SOX12 or DNMT3b was examined by a luciferase assay. Cell proliferation, migration, and invasion were attenuated by miR-29b, whereas knockdown of SOX12 and DNMT3b could block SW1990 malignant activity. Further, the double luciferase assay showed that miR-29b can target SOX12 and DNMT3b directly by binding to their 3'-untranslated region. Finally, a rescue experiment was conducted by transfecting miR-29b and SOX12 overexpressed plasmid into cells. Cell proliferation, migration, and invasion inhibition induced by miR-29b were reversed by SOX12 overexpression, and revail of the expression of DNMT3b. MiR-29b suppressed proliferation, migration, and invasion by directly targeting SOX12 and DNMT3b in pancreatic cancer cells, and DNMT3b might be a target gene of SOX12.

Clinical Implication of MicroRNAs in Molecular Pathology: An Update for 2018

MicroRNAs (miRNAs) are poised to provide diagnostic, prognostic, and therapeutic targets for several diseases including malignancies for precision medicine applications. The miRNAs have immense potential in the clinical arena because they can be detected in the blood, serum, tissues (fresh and formalin-fixed paraffin-embedded), and fine-needle aspirate specimens. The most attractive feature of miRNA-based therapy is that a single miRNA could be useful for targeting multiple genes that are deregulated in cancers, which can be further investigated through systems biology and network analysis that may provide cancer-specific personalized therapy.

Can we predict long-term survival in resectable pancreatic ductal adenocarcinoma?

Objective

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive tumour associated with poor 5-year survival. We aimed to determine factors which differentiate short and long-term survivors and identify a prognostic biomarker.

Methods

Over a ten-year period, patients with resected PDAC who developed disease recurrence within 12 months (Group I) and those who had no disease recurrence for 24 months (Group II) were identified. Clinicopathological data was analysed. Ion Torrent high-throughput sequencing on DNA extracted from FFPE tumour samples was used to identify mutations. Additionally, peripheral blood samples were analysed for variants in cell-free DNA, circulating tumour cells (CTCs), and microRNAs.

Results

Multivariable analysis of clinicopathological factors showed that a positive medial resection margin was significantly associated with short disease-free survival (p = 0.007). Group I patients (n = 21) had a higher frequency of the KRAS mutant mean variant allele (16.93% ± 11.04) compared to those in Group II (n = 13; 7.55% ± 5.76, p = 0.0078). Group I patients also trended towards having a KRAS c.35G>A p.Gly12Asp mutation in addition to variants in other genes, such as TP53, CDKN2A, and SMAD4. Mutational status of cell-free DNA, and number of CTCs, was not found to be useful in this study. A circulating miRNA (hsa-miR-548ah-5p) was found to be significantly differentially expressed.

Conclusions

Medial resection margin status and the frequency of KRAS mutation in the tumour tissue are independent prognostic indicators for resectable PDAC. Circulating miRNA hsa-miR-548ah-5p has the potential to be used as a prognostic biomarker.

Involvement of microRNA-423 Gene Variability in Breast Cancer Progression in Saudi Arabia

Aim:

microRNA-423 is an oncogenic factor which is frequently upregulated in cancer. However, associations with breast cancer risk remain inconsistent. Therefore, we investigated the prevalence of microRNA-423 rs6505162C>T gene variation with breast cancer susceptibility in Saudi women.

Methodology:

This study was conducted on 100 breast cancer patients and 124 matched healthy individuals. Genotyping of the microRNA-423 rs6505162C/T gene variation was performed by using the amplification refractory mutation system PCR method (ARMS-PCR).

Results:

A significant difference was observed in the genotype distribution between the breast cancer cases and controls (p=0.0001), the frequencies of the genotypes CC,CT and TT being 25%, 52% and 23% in patients and 65%,20% and 15% respectively, in controls. The microRNA-423 C>T variant was associated with an increased risk of breast cancer in codominant models for (OR = 6.73, 95 % CI, 3.50-12.97; RR 2.35(1.67-3.30, p=0.0001) the microRNA-423TT genotype and (OR = 4.14, 95 % CI, 1.93-8.87; p=0.0003) microRNA-423CT (OR= 6.73, 95% CI, 3.50-12.97; p=0.0001) and also with the dominant model (OR 5.6(3.14-1.01), p=0.0001) CT+TT vs CC) with a non-significant association for the recessive model (OR=1.75, 95%CI=0.08-3.44, P=0.139, TT vs CC+CT). The T allele significantly increased the risk of breast cancer (OR =2.63, 95 % CI, 1.77-3.91; p=0.001) compared to the C allele. Some 6.73 ,4.14 and 2.63 fold increased risk of developing breast cancer was associated with TT and CT genotypes and the T allele of microRNA-423 in the northwestern region of Saudi Arabia.

Conclusion:

Our findings indicate that the microRNA-423 TT genotype and the T allele are associated with an increased susceptibility, metastasis and advanced stage of breast cancer in Saudi Arabian patients. Further studies with larger sample sizes are necessary to confirm our findings.

The association between miR-423 rs6505162 polymorphism and cancer susceptibility: a systematic review and meta-analysis

The association between miR-423 polymorphism (C > A) and the risk of different cancers are still controversial. We performed a meta-analysis to clarify its association with multiple cancer risks. PubMed and Embase (as of 10th September, 2016) were searched. A total of 17 studies from 16 articles, consisting of 8,582 cases and 10,291 controls, were finally qualified and enrolled in this meta-analysis. The pooled results showed that the miR-423 AA genotype was associated with decreased cancer risk under the recessive model (odds ratio [OR] = 0.87, 95% confidence interval [CI]: 0.78~0.98, P = 0.020). However, this association became non-significant after excluding the study with the smallest odds ratio. Subgroup analyses revealed a significant decrease in risk of lung cancer (dominant model: OR = 0.73, 95 % CI: 0.60~0.89, P = 0.002; recessive model: OR = 0.59, 95 % CI: 0.37~0.95, P = 0.031). Our study indicates that miR-423 rs6505162 might be associated with a reduced risk of cancers, however, this finding need to be evaluated further in larger samples, especially subgroup analyses. In addition, cancer-specific functional studies are especially needed to reveal the underlying mechanisms between miR-423 and the etiology of cancer.

Highly expressed placental miRNAs control key biological processes in human cancer cell lines

Despite being a healthy tissue, the constituent cells of the placenta, share similar characteristics with tumor cells, such as increased cell growth, migration, and invasion. However, while these processes are stochastic and uncontrolled in cancer cells, in placenta they are precisely controlled. Since miRNAs have been reported to regulate genes that control the molecular mechanisms necessary for the development of both human placenta and cancer, we addressed for miRNAs highly expressed in the placenta that could be involved in tumorigenesis. Here, we assessed the miRNA profile in placenta samples using microarray analysis. The results showed that miR-451 and miR-720, highly expressed placental miRNAs, presented very low or undetectable expression in cancer cell lines compared to the normal placenta and healthy tissues. Additionally, transfection of miR-451 or miR-720 mimics in choriocarcinoma cell line (JEG3) and colorectal adenocarcinoma cell line (HT-29) resulted in impaired cell proliferation, decreased cell migration and invasion and reduced ability of colony formation. These findings provide evidence that placenta may work as an alternative model to identify novel miRNAs involved in pathways controlling tumorigenesis.

Next-generation sequencing reveals microRNA markers of adrenocortical tumors malignancy

Background

Adrenocortical carcinoma is a rare finding among common adrenocortical tumors, but it is highly aggressive and requires early detection and treatment. Still, the differential diagnosis between benign and malignant lesions is difficult even for experienced pathologists and there is a significant need for novel diagnostic methods. In this study we aimed to reveal a complete set of microRNAs expressed in the adrenal gland and to identify easily detectable, stable and objective biomarkers of adrenocortical malignancy.

Methods

We employed next-generation sequencing to analyze microRNA profiles in a unique set of 51 samples, assigned to either a learning dataset including 7 adrenocortical carcinomas (ACCs), 8 adrenocortical adenomas (AAs) and 8 control samples (NAs), or a validation dataset including 8 ACCs, 10 AAs and 10 NAs. The results were validated in real-time Q-PCR.

Results

We detected 411 miRNAs expressed in 1763 length isoforms in the examined samples. Fifteen miRNAs differentiate between malignant (ACC) and non-malignant (AA + NA) tissue in the test set of independent samples. Expression levels of 6 microRNAs, miR-503-5p, miR-483-3p, miR-450a-5p, miR-210, miR-483-5p, miR-421, predict sample status (malignancy/non-malignancy) with at least 95% accuracy in both datasets. The best single-gene malignancy marker, miR-483-3p, has been validated by real-time RT PCR.

Conclusions

As a result of the study we propose clinically valid and easily detectable biomarkers of adrenocortical malignancy that may significantly facilitate morphological examination. Since microRNAs can be detected in blood, the study brings tools for development of non-invasive diagnostics of adrenocortical carcinomas.

miR-128 induces pancreas cancer cell apoptosis by targeting MDM4

MicroRNAs (miRNA/miRs) are small, non-coding RNA molecules (19-25 nucleotides in length), which function to regulate gene expression. It has been reported that miR-128 serves an important role in regulating cancer cell growth; increasing evidence has indicated that the expression of miR-128 is decreased in pancreatic cancer (PC) cells. However, the specific mechanisms of miR-128 in regulating PC cell growth are unclear. In the present study, it was confirmed that the expression of miR-128 was significantly decreased within PC tissues compared with adjacent normal tissues via reverse transcription-quantitative polymerase chain reaction analysis. In addition, miR-128 mimics inhibited PC MIA-PaCa2 cell growth by enhancing cell apoptosis in a caspase-dependent manner. Furthermore, the results of the present study demonstrated that double minute 4 (MDM4) may be a direct target for miR-128 via a dual luciferase report assay; miR-128 may inhibit MDM4 expression, and increase p53 and cleaved caspase-3 protein expression levels. In summary, the present study indicated that miR-128 is downregulated in PC, and it may be a promising target for future PC diagnosis and treatment.

miR-423-5p serves as a diagnostic indicator and inhibits the proliferation and invasion of ovarian cancer

MicroRNA (miR)-423-5p is a potential target for the diagnosis and therapy of heart failure and cancer. The present study aimed to investigate the expression and role of miR-423-5p in ovarian cancer. miR-423-5p expression in ovarian tissues and plasma collected from ovarian cancer patients and healthy volunteers was analyzed by polymerase chain reaction analysis. In addition, a cell proliferation assay, clonogenic assay and Matrigel-based assay were performed to evaluate the role of miR-423-5p in ovarian cancer cells. The results demonstrated that miR-423-5p was downregulated in ovarian cancer tissues and plasma from ovarian cancer patients, compared with healthy individuals. Of note, miR-423-5p expression in ovarian tissues and plasma was demonstrated to be inversely correlated with ovarian cancer progression. Transfection with miR-423-5p efficiently increased miR-423-5p expression in A2780-s and A2780-cp cells, which had low miR-423-5p expression. Ectopic overexpression of miR-423-5p reduced cell proliferation, colony formation and invasion of ovarian cancer cells. In conclusion, the present study indicated that miR-423-5p may serve as a diagnostic indicator and functions as a tumor suppressor in ovarian cancer.

Plasma microRNA panels to diagnose pancreatic cancer: Results from a multicenter study

Biomarkers for the early diagnosis of pancreatic cancer (PC) are urgent needed. Plasma microRNAs (miRNAs) might be used as biomarkers for the diagnosis of cancer. We analyzed 361 plasma samples from 6 surgical centers in China and performed machine learning approach. We gain insight of the association between the aberrant plasma miRNA expression and pancreatic disease. 671 microRNAs were screened in the discovery phase and 33 microRNAs in the training phase and 13 microRNAs in the validation phase. After the discovery phase and training phase, 2 diagnostic panels were constructed comprising 3 microRNAs in panel I (miR-486-5p, miR-126-3p, miR-106b-3p) and 6 microRNAs in panel II (miR-486-5p, miR-126-3p, miR-106b-3p, miR-938, miR-26b-3p, miR-1285). Panel I and panel II had high accuracy for distinguishing pancreatic cancer from chronic pancreatitis (CP) with area under the curve (AUC) values of 0.891 (Standard Error (SE): 0.097) and 0.889 (SE: 0.097) respectively, in the validation phase. Additionally, we demonstrated that the diagnostic value of the panels in discriminating PC from CP were comparable to that of carbohydrate antigen 19–9 (CA 19–9) 0.775 (SE: 0.053) (P = 0.1 for both). This study identified 2 diagnostic panels based on microRNA expression in plasma with the potential to distinguish PC from CP. These patterns might be developed as biomarkers for pancreatic cancer.

Usefulness of exosome-encapsulated microRNA-451a as a minimally invasive biomarker for prediction of recurrence and prognosis in pancreatic ductal adenocarcinoma

BACKGROUND

MicroRNAs (miRNAs) encapsulated in the exosomes of plasma is of interest as stable and minimally invasive biomarkers for recurrence and prognosis in cancer patients. The aim of this study was to clarify the predictive and prognostic value of plasma exosomal microRNA-451a (miR-451a) in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Microarray-based expression profiling of miRNAs derived from exosomes in the plasma of six PDAC patients with UICC stage II was employed to identify a biomarker to distinguish between patients with and without recurrence. For validation analysis, plasma exosome samples of other 50 PDAC patients were measured by TaqMan MicroRNA assays.

RESULTS

In the miRNA microarray analyses, miR-451a showed the highest upregulation in the stage II patients who showed recurrence after surgery. In the relationship to pathological factors, exosomal miR-451a showed a significant association with tumor size and stage. The overall survival (OS) and disease-free survival rates (DFS) of the high exosomal miR-451a patients were significantly worse than those of the low miR-451a patients. In Cox proportional hazards model analysis, exsomal miR-451a showed significance to OS and DFS.

CONCLUSIONS

Plasma exosomal miR-451a levels may be a useful minimally invasive biomarker for the prediction of recurrence and prognosis in PDAC patients.

MiR-486 as an effective biomarker in cancer diagnosis and prognosis: a systematic review and meta-analysis

Purpose

MiR-486 was found to be associated with cancer’s diagnosis and prognosis. This meta-analysis aimed to investigate the potential effect of miR-486 on cancer detection and prognosis.

Materials and Methods

We searched PubMed, Cochrane library, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases to find all correlated articles. The STATA 11.0 was applied to estimate the pooled effects, heterogeneity and publication bias.

Results

The pooled sensitivity (SEN), specificity (SPE) and Area under the curve (AUC) were 82% (95% CI: 78–85%), 88% (95% CI: 83–92%) and 0.91 (95% CI: 0.88–0.93). Subgroup analysis indicated miR-486 from circulating samples exhibited higher diagnostic accuracy with the AUC was 0.90 (95% CI: 0.87–0.92) than miR-486 from other specimen with the AUC of 0.78 (95% CI: 0.75–0.82) and miR-486 obtained a better diagnostic value in the Asian population with the AUC of 0.94 (95% CI: 0.91–0.95) than the Caucasian and Caucasian/African population with the AUC of 0.80 (95% CI: 0.76–0.83) and 0.89 (95% CI: 0.86–0.91) respectively. MiR-486 obtained high value for the diagnosis of non-small cell lung cancer with SEN, SPE and AUC were 0.82 (95% CI: 0.0.77–0.87), 0.90 (95% CI: 0.84–0.94) as well as 0.92 (95% CI: 0.89–0.94) respectively. For the 7 prognostic tests, the pooled hazard ratio (HR) was 0.48 (95% CI: –0.13–1.08) for low versus high miR-486 expression.

Conclusions

This meta-analysis indicated that miR-486 can be used as ideal biomarkers in the cancer’s diagnosis. However, Low miR-486 expression did not increase the risk of poor outcome.

Direct repression of the oncogene CDK4 by the tumor suppressor miR-486-5p in non-small cell lung cancer

MicroRNAs are a class of non-coding single-stranded RNA, 20-23 nucleotide in length, which can be involved in the regulation of gene expression. Through binding with 3′-untranslated regions (3′-UTR), microRNAs can cause degradation of target mRNAs or inhibition of translation, and thus regulating the expression of genes at the post-transcriptional level. In this study, we found that miR-486-5p was significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, suggesting that miR-486-5p might function as a tumor suppressor in lung cancer. Additionally, we showed that CDK4, an oncogene that plays an important role in cell cycle G1/S phase progression, was directly targeted by miR-486-5p. Furthermore, our data reveals that knockdown of CDK4 by siRNA can inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression. In epigenetics, the upstream promoter of miR-486-5p was strongly regulated by methylation in NSCLC. Collectively, our results suggest that miR-486-5p could not only inhibit NSCLC by downregulating the expression of CDK4, but also be as a promising and potent therapy in the near future.

ANK1 Methylation regulates expression of MicroRNA-486-5p and discriminates lung tumors by histology and smoking status

The intragenic tumor-suppressor microRNA miR-486-5p is often down-regulated in non-small cell lung cancer (NSCLC) but the mechanism is unclear. This study investigated epigenetic co-regulation of miR-486-5p and its host gene ANK1. MiR-486-5p expression in lung tumors and cell lines was significantly reduced compared to normal lung (p < 0.001) and is strongly correlated with ANK1 expression. In vitro, siRNA-mediated ANK1 knockdown in NSCLC cells also reduced miR-486-5p while the DNA methylation inhibitor 5-aza-2'-deoxycytidine induced expression of both. ANK1 promoter CpG island was unmethylated in normal lung but methylated in 45% (118/262) lung tumors and 55% (17/31) NSCLC cell lines. After adjustment for tumor histology and smoking, methylation was significantly more prevalent in adenocarcinoma (101/200, 51%) compared to squamous cell carcinoma (17/62, 27%), p < 0.001; HR = 3.513 (CI: 1.818-6.788); and in smokers (73/128, 57%) than never-smokers (28/72, 39%), p = 0.014; HR = 2.086 (CI: 1.157-3.759). These results were independently validated using quantitative methylation data for 809 NSCLC cases from The Cancer Genome Atlas project. Together, our data indicate that aberrant ANK1 methylation is highly prevalent in lung cancer, discriminate tumors by histology and patients' smoking history, and contributes to miR-486-5p repression.

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

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

NO• and Pancreatic Cancer: A Complex Interaction with Therapeutic Potential

SIGNIFICANCE

Pancreatic tumors express high level of nitric oxide synthases (NOSs) in particular inducible (iNOS/NOS2) and endothelial (eNOS/NOS3) forms. However, the role of nitric oxide (NO^•) in the development and progression of pancreatic cancer is not clearly defined. Delineating the NO^•-induced signaling in pancreatic cancer and its potential contribution in disease aggressiveness may provide therapeutic targets to improve survival in this lethal malignancy. Recent Advances: An increased expression of NOS2/iNOS in tumors is associated with poorer survival in early stage resected patients with pancreatic ductal adenocarcinoma (PDAC). Furthermore, genetic deletion of NOS2 enhanced survival in mice with autochthonous PDAC. Additionally, targeting NOS3/eNOS reduced the abundance of precursor lesions in mice, which trended toward improved survival.

CRITICAL ISSUES

The extremely poor prognosis in pancreatic cancer is due to the late diagnosis and lack of effective therapy in advanced disease. One of the most critical issues is to decipher the underlying mechanism of disease aggressiveness and therapeutic resistance for identifying potential therapeutic target and effective treatment. Given the evidence of a strong association between inflammation and pancreatic cancer and clinical evidence, which suggests an association between NOS2 and disease aggressiveness, it is critical to define the role of NO^• signaling in this lethal malignancy.

FUTURE DIRECTIONS

Recent preclinical and clinical evidences indicate a potential therapeutic significance of targeting NO^• signaling in pancreatic cancer. With the emergence of new preclinical models, including the patient-derived organoids, further preclinical evaluation using clinically tested NOS inhibitors is needed for designing future clinical investigation. Antioxid. Redox Signal. 26, 1000-1008.

Circulating miRNA-21-5p as a diagnostic biomarker for pancreatic cancer: evidence from comprehensive miRNA expression profiling analysis and clinical validation

Pancreatic cancer (PC) is a highly fatal disease worldwide and is often misdiagnosed in its early stages. The exploration of novel non-invasive biomarkers will definitely benefit PC patients. Recently, circulating miRNAs in body fluids are emerging as non-invasive biomarkers for PC diagnosis. In this study, we first conducted comprehensive robust rank aggregation (RRA) analysis based on 21 published miRome profiling studies. We statistically identified and clinically validated a miRNA expression pattern in PC patients. These miRNAs consisted of four up-regulated (hsa-miR-21-5p, hsa-miR-31-5p, hsa-miR-210-3p and hsa-miR-155-5p) and three down-regulated miRNAs (hsa-miR-217, hsa-miR-148a-3p and hsa-miR-375). Among them, hsa-miR-21-5p was one of the most highly expressed miRNAs in the serum of PC patients. Our validation test further suggested a relatively high accuracy of serum hsa-miR-21-5p levels in the diagnosis of PC, with a sensitivity of 0.77 and a specificity of 0.80. Finally, a diagnostic meta-analysis based on 9 studies also revealed favorable sensitivity and specificity of circulating hsa-miR-21-5p for the diagnosis of PC (pooled sensitivity and specificity were 0.76 and 0.74, respectively), which was consistent with our findings. Taken together, as one of the most aberrantly expressed miRNAs in PC, circulating hsa-miR-21-5p might be a promising serum biomarker in patients with PC.

The Evolving Role of Pathology in New Developments, Classification, Terminology, and Diagnosis of Pancreatobiliary Neoplasms

Pancreatobiliary tract lesions are increasingly being discovered because of more sensitive imaging modalities. Magnetic resonance imaging has identified incidental pancreatic cysts in 13.5% of patients of progressively increasing age. Pancreatobiliary tissue is more accessible through endoscopic ultrasound and magnetic resonance imaging-guided biopsy procedures, and is now an integral part of pathologists' routine practice. Accordingly, several new tumor categories have been recently recognized, including intraductal tubulopapillary neoplasm, a new addition to tumoral intraepithelial neoplasms. Other entities have been reclassified, including the recent transition to 2-tiered grading of preinvasive neoplasms, as well as new perspectives on the distinctive biologic behavior of oncocytic intraductal papillary mucinous neoplasms (IPMNs) compared with other IPMN subtypes. This has led to proposals for revised staging of virtually every segment of the pancreatobiliary tree, with theranostic markers becoming an integral part of workup. Ki-67 is now an integral part of the classification of neuroendocrine tumors, with new definitions of "high-grade neuroendocrine carcinoma." Although bile duct brushings have opened new avenues for diagnosis, their sensitivity remains low and often requires concomitant fluorescent in situ hybridization to better define ambiguous cases. Various molecular pathways have been elucidated for pancreatic cysts, including KRAS for ductal neoplasia, GNAS for intestinal IPMNs, RNF3 for mucinous cysts, and VHL for serous cystic neoplasms, all key players in diagnostic workup. Integration of these updates into our understanding of pancreatobiliary disease requires active engagement of pathologists for appropriate specimen triage, judicious interpretation of results, and incorporation into reporting and staging. They also provide exciting opportunities for targeted therapy.

Pancreatic Cancer, A Mis-interpreter of the Epigenetic Language

Pancreatic cancer is the third leading cause of cancer mortality in the U.S. with close to 40,000 deaths per year. Pancreatic ductal adenocarcinoma (PDAC) represents approximately 90 percent of all pancreatic cancer cases and is the most lethal form of the disease. Current therapies for PDAC are ineffective and most patients cannot be treated by surgical resection. Most research efforts have primarily focused on how genetic alterations cause, alter progression, contribute to diagnosis, and influence PDAC management. Over the past two decades, a model has been advanced of PDAC initiation and progression as a multi-step process driven by the acquisition of mutations leading to loss of tumor suppressors and activation of oncogenes. The recognition of the essential roles of these genetic alterations in the development of PDAC has revolutionized our knowledge of this disease. However, none of these findings have turned into effective treatment for this dismal malignancy. In recent years, studies in the areas of chromatin modifications, and non-coding RNAs have uncovered mechanisms for regulating gene expression which occur independently of genetic alterations. Chromatin-based mechanisms are interwoven with microRNA-driven regulation of protein translation to create an integrated epigenetic language, which is grossly dysregulated in PDAC. Thus in PDAC, key tumor suppressors that are well established to play a role in PDAC may be repressed, and oncogenes can be upregulated secondary to epigenetic alterations. Unlike mutations, epigenetic changes are potentially reversible. Given this feature of epigenetic mechanisms, it is conceivable that targeting epigenetic-based events promoting and maintaining PDAC could serve as foundation for the development of new therapeutic and diagnostic approaches for this disease.

miR‑1246 and miR‑4644 in salivary exosome as potential biomarkers for pancreatobiliary tract cancer

Pancreatobiliary tract cancer is a highly fatal cancer. Detection of pancreatobiliary tract cancer is difficult because it lacks typical clinical symptoms and because of its anatomical location. Biomarker discovery is therefore important to detect pancreatobiliary tract cancer in its early stage. A study demonstrated that expression levels of miR‑1246, miR‑3976, miR‑4306, and miR‑4644 in serum exosomes were higher in pancreatic cancer patients than these levels in healthy control participants. Supposing that microRNA (miRNA) expression profiles in saliva are similar to those in serum, four miRNAs (miR‑1246, miR‑3976, miR‑4306, and miR‑4644) in salivary exosomes may also be useful for detection of pancreatobiliary tract cancer. In this study, it was examined whether these miRNAs could be used as biomarkers for pancreatobiliary tract cancer. Twelve pancreatobiliary tract cancer patients and 13 healthy control participants were analyzed as a cancer and a control group, respectively. Unstimulated whole saliva was collected, salivary exosomes were isolated, and total RNA was extracted. Using quantitative real‑time PCR (RT‑qPCR), the relative expression ratios of miR‑1246 and miR‑4644 were significantly higher in the cancer group than these ratios in the control group. Receiver operating characteristic (ROC) curves were constructed to analyze the discrimination power of these miRNAs. For miR‑1246, the results yielded an area under the curve (AUC) of 0.814 (P=0.008). For miR‑4644, the results yielded an AUC of 0.763 (P=0.026). For the combination of miR‑1246 and miR‑4644, the results yielded an increased AUC of 0.833 (P=0.005). This pilot study suggests that miR‑1246 and miR‑4644 in salivary exosomes could be candidate biomarkers for pancreatobiliary tract cancer.

MicroRNA-486-5p enhances hepatocellular carcinoma tumor suppression through repression of IGF-1R and its downstream mTOR, STAT3 and c-Myc

The insulin-like growth factor (IGF)-axis has been paradigmatically involved in hepatocellular carcinoma (HCC) tumor initiation, progression and drug resistance. Consequently, members of the IGF-axis and most importantly, IGF-1 receptor (IGF-1R) have been considered as intriguing targets for HCC therapy. Few miRNAs have been recently reported to be associated with IGF-1R regulation. The present study aimed to investigate the role of microRNA (miRNA/miR)-486-5p in the regulation of IGF-1R and its downstream signaling cascades. miR-486-5p was markedly downregulated in hepatitis C virus-induced HCC tissues and Huh-7 cells. Forcing the expression of miR-486-5p in Huh-7 cells resulted in the repression of IGF-1R, mammalian target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3) and c-Myc mRNA levels. Ectopic expression of miR-486-5p in Huh-7 cells markedly repressed cellular viability, proliferation, migration and clonogenicity in a similar pattern to IGF-1R small interfering RNAs, and were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, BrdU incorporation, wound healing and colony forming assays, respectively. Overall, the study findings demonstrated that miR-486-5p acts as a tumor suppressor in HCC through the repression of essential members of the IGF-axis, including IGF-1R and its downstream mediators mTOR, STAT3 and c-Myc.

miR-486-5p inhibits cell growth of papillary thyroid carcinoma by targeting fibrillin-1

Previous studies have demonstrated that miR-486-5p functions as a tumor suppressor or oncogene in various types of cancer. In the present study, we showed that miR-486-5p was significantly down-regulated in papillary thyroid carcinoma (PTC) tissues and cell lines, whereas miR-486-5p down-regulation inhibited PTC cell proliferation and increased apoptosis. Conversely, under-expression of miR-486-5p enhanced PTC cell proliferation and decreased apoptosis. Fibrillin-1 (FBN1) was shown to be a direct target of miR-486-5p and inversely regulated by miR-486-5p. FBN1 silencing led to decreased PTC cell proliferation and enhanced apoptosis in vitro, similar to that mediated by miR-486-5p. Furthermore, miR-486-5p over-expression or FBN1 knock-down inhibited, while up-regulation of FBN1 boosted xenograft tumor formation in vivo. Our data suggest that miR-486-5p induces PTC cell growth inhibition and apoptosis by targeting and suppressing FBN1. Thus, miR-486-5p/FBN1 might provide a promising therapeutic target for PTC treatment.

Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells

Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 and p27 CDK-inhibitors. Let-7d also decreased sarcosphere-and-colony forming ability, two features associated with self-renewing, and it reduced the expression of stemness genes, including Oct3/4, Sox2, Nanog, Lin28B, and HMGA2. Moreover, let-7d induced mesenchymal-to-epithelial-transition, as shown by both N-Cadherin-E-cadherin-switch and decrease in vimentin. Surprisingly, such switch was accompanied by enhanced migratory/invasive capacities, with a strong increase in MMP9, CXCR4 and VersicanV1. Let-7d- overexpression also reduced cell sensitivity to apoptosis induced by both serum-starvation and various chemotherapy drugs, concomitant with decrease in caspase-3 and increase in BCL2 expression. Our data suggest that let-7d in 3AB-OS-CSCs could induce plastic-transitions from CSCs-to-non-CSCs and vice-versa. To our knowledge this is the first study to comprehensively examine the expression and functions of let-7d in OS-CSCs. By showing that let-7d has both tumor suppressor and oncogenic functions in this context, our findings suggest that, before prospecting new therapeutic strategies based on let-7d modulation, it is urgent to better define its multiple functions. J. Cell. Physiol. 231: 1832-1841, 2016. © 2015 Wiley Periodicals, Inc.

MicroRNA in pancreatic ductal adenocarcinoma and its precursor lesions

Pancreatic ductal adenocarcinoma (PDAC) is the 4^th deadliest cancer in the United States, due to its aggressive nature, late detection, and resistance to chemotherapy. The majority of PDAC develops from 3 precursor lesions, pancreatic intraepithelial lesions (PanIN), intraductual papillary mucinous neoplasm (IPMN), and mucinous cystic neoplasm. Early detection and surgical resection can increase PDAC 5-year survival rate from 6% for Stage IV to 50% for Stage I. To date, there are no reliable biomarkers that can detect PDAC. MicroRNAs (miRNA) are small noncoding RNAs (18-25 nucleotides) that regulate gene expression by affecting translation of messenger RNA (mRNA). A large body of evidence suggests that miRNAs are dysregulated in various types of cancers. MiRNA has been profiled as a potential biomarker in pancreatic tumor tissue, blood, cyst fluid, stool, and saliva. Four miRNA biomarkers (miR-21, miR-155, miR-196, and miR-210) have been consistently dysregulated in PDAC. MiR-21, miR-155, and miR-196 have also been dysregulated in IPMN and PanIN lesions suggesting their use as early biomarkers of this disease. In this review, we explore current knowledge of miRNA sampling, miRNA dysregulation in PDAC and its precursor lesions, and advances that have been made in using miRNA as a biomarker for PDAC and its precursor lesions.

A transcriptional miRNA-gene network associated with lung adenocarcinoma metastasis based on the TCGA database

Lung adenocarcinoma is the most common subtype of non-small cell lung cancer (NSCLC), leading to the largest number of cancer-related deaths worldwide. The high mortality rate may be attributed to the delay of detection. Therefore, it is of great importance to explore the mechanism of lung adenocarcinoma metastasis and the strategy to block metastasis of the disease. We searched and downloaded mRNA and miRNA expression data and clinical data from The Cancer Genome Atlas (TCGA) database to identify differences in mRNA and miRNA expression of primary tumor tissues from lung adenocarcinoma that did and did not metastasize. In addition, combined with bioinformatic prediction, we constructed an miRNA-target gene regulatory network. Finally, we employed RT-qPCR to validate the bioinformatic approach by determining the expression of 10 significantly differentially expressed genes which were also putative targets of several dysregulated miRNAs. RT-qPCR results indicated that the bioinformatic approach in our study was acceptable. Our data suggested that some of the genes including PKM2, STRAP and FLT3, may participate in the pathology of lung adenocarcinoma metastasis and could be applied as potential markers or therapeutic targets for lung adenocarcinoma.