Identification of microRNA-21 as a biomarker for chemoresistance and clinical outcome following adjuvant therapy in resectable pancreatic cancer

Diagnostic and Prognostic Accuracy of MiRNAs in Pancreatic Cancer: A Systematic Review and Meta-Analysis

Pancreatic cancer (PC) remains a significant contributor to global cancer mortality, with limited effective diagnostic and prognostic tools. MicroRNAs (miRNAs) have emerged as promising biomarkers for PC diagnosis and prognosis. A comprehensive literature search was conducted in PubMed, Web of Science, and Scopus. Studies reporting sensitivity, specificity or area under the curve (AUC) for miRNAs in PC diagnosis, as well as hazard ratios (HRs) for survival evaluations, were included. Data extraction and quality assessment followed PRISMA guidelines. Meta-analyses were conducted using appropriate statistical methods. The protocol is registered in PROSPERO. Diagnostic analysis included 290 evaluations, revealing an overall AUC of 0.8226 for PC diagnosis. Subgroup analyses showed varying accuracies, with blood and tissue specimens yielding higher AUC values. Promising miRNAs with AUC values above 0.8 included miR-320, miR-1290, miR-93, miR-25, miR-451, miR-20, miR-21, miR-223 and miR-122. Prognostic analysis encompassed 46 studies, indicating significant associations between miRNA expression and overall survival (OS) and progression-free survival (PFS). The combined HR for studies reporting OS HRs higher than one was 1.7613 (95% CI: 1.5394-2.0152, p < 0.0001; I2 = 81.7%). Notable miRNAs with prognostic significance included miR-10, miR-21 and miR-221. Studies reporting OS HRs less than one had a pooled HR of 0.6805 (95% CI: 0.5862-0.7901, p < 0.0001; I2 = 65.4%). MiRNAs hold promise as diagnostic and prognostic biomarkers for PC. Blood and tissue specimens offer superior diagnostic accuracy, and several miRNAs show potential for predicting patient outcomes.

The oncogenic potential of salivary microRNA-93 and microRNA-412-3p in oral lichen planus: a case-control study

BACKGROUND

Oral Lichen Planus is one of the most popular chronic mucocutaneous diseases. It is classified as potentially malignant lesions. Many microRNAs can be used as biological markers for the disease and for its malignant transformation. The aim of the study to measure the expression of microRNA-93 and microRNA-412-3p in Oral Lichen Planus patients, patients diagnosed as Oral Squamous Cell Carcinoma and healthy controls.

METHODOLOGY

A total of 60 patients were divided into 3 groups; each group contains 20 patients. Group I for Oral Lichen Planus patients, group II for healthy controls and group III for Oral Squamous cell carcinoma patients. All of these patients were chosen from those attending Kasr Al-Einy hospital, Cairo University. After full diagnosis and matching of our eligibility criteria, saliva sample was taken from each patient to measure the concentration of microRNA-93 and microRNA-412-3p.

RESULTS

Both microRNA-93 and miceoRNA-412-3p were upregulated in Oral Squamous cell carcinoma patients than Oral Lichen patients than controls and both of them had great sensitivity, specificity and diagnostic accuracy for both Oral Lichen Planus and Oral Squamous cell carcinoma.

CONCLUSION

MicroRNA-93 and micriRNA-412-3p can be used as diagnostic markers and for the oncogenic potential of Oral Lichen Planus.

Personalized treatment using predictive biomarkers in solid organ malignancies: A review

In recent years, the influence of specific biomarkers in the diagnosis and prognosis of solid organ malignancies has been increasingly prominent. The relevance of the use of predictive biomarkers, which predict cancer response to specific forms of treatment provided, is playing a more significant role than ever before, as it affects diagnosis and initiation of treatment, monitoring for efficacy and side effects of treatment, and adjustment in treatment regimen in the long term. In the current review, we explored the use of predictive biomarkers in the treatment of solid organ malignancies, including common cancers such as colorectal cancer, breast cancer, lung cancer, prostate cancer, and cancers associated with high mortalities, such as pancreatic cancer, liver cancer, kidney cancer and cancers of the central nervous system. We additionally analyzed the goals and types of personalized treatment using predictive biomarkers, and the management of various types of solid organ malignancies using predictive biomarkers and their relative efficacies so far in the clinical settings.

miRNAs in pancreatic cancer progression and metastasis

Small non-coding RNA or microRNA (miRNA) are critical regulators of eukaryotic cells. Dysregulation of miRNA expression and function has been linked to a variety of diseases including cancer. They play a complex role in cancers, having both tumour suppressor and promoter properties. In addition, a single miRNA can be involved in regulating several mRNAs or many miRNAs can regulate a single mRNA, therefore assessing these roles is essential to a better understanding in cancer initiation and development. Pancreatic cancer is a leading cause of cancer death worldwide, in part due to the lack of diagnostic tools and limited treatment options. The most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), is characterised by major genetic mutations that drive cancer initiation and progression. The regulation or interaction of miRNAs with these cancer driving mutations suggests a strong link between the two. Understanding this link between miRNA and PDAC progression may give rise to novel treatments or diagnostic tools. This review summarises the role of miRNAs in PDAC, the downstream signalling pathways that they play a role in, how these are being used and studied as therapeutic targets as well as prognostic/diagnostic tools to improve the clinical outcome of PDAC.

The Multifaceted Role of miR-21 in Pancreatic Cancers

With the lack of specific signs and symptoms, pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at late metastatic stages, resulting in poor survival outcomes. Among various biomarkers, microRNA-21 (miR-21), a small non-coding RNA, is highly expressed in PDAC. By inhibiting regulatory proteins at the 3' untranslated regions (UTR), miR-21 holds significant roles in PDAC cell proliferation, epithelial-mesenchymal transition, angiogenesis, as well as cancer invasion, metastasis, and resistance therapy. We conducted a systematic search across major databases for articles on miR-21 and pancreatic cancer mainly published within the last decade, focusing on their diagnostic, prognostic, therapeutic, and biological roles. This rigorous approach ensured a comprehensive review of miR-21's multifaceted role in pancreatic cancers. In this review, we explore the current understandings and future directions regarding the regulation, diagnostic, prognostic, and therapeutic potential of targeting miR-21 in PDAC. This exhaustive review discusses the involvement of miR-21 in proliferation, epithelial-mesenchymal transition (EMT), apoptosis modulation, angiogenesis, and its role in therapy resistance. Also discussed in the review is the interplay between various molecular pathways that contribute to tumor progression, with specific reference to pancreatic ductal adenocarcinoma.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

Non-invasive biomarkers for early diagnosis of pancreatic cancer risk: metabolite genomewide association study based on the KCPS-II cohort

BACKGROUND

Pancreatic cancer is a lethal disease with a high mortality rate. The difficulty of early diagnosis is one of its primary causes. Therefore, we aimed to discover non-invasive biomarkers that facilitate the early diagnosis of pancreatic cancer risk.

METHODS

The study subjects were randomly selected from the Korean Cancer Prevention Study-II and matched by age, sex, and blood collection point [pancreatic cancer incidence (n = 128) vs. control (n = 256)]. The baseline serum samples were analyzed by non-targeted metabolomics, and XGBoost was used to select significant metabolites related to pancreatic cancer incidence. Genomewide association study for the selected metabolites discovered valuable single nucleotide polymorphisms (SNPs). Moderation and mediation analysis were conducted to explore the variables related to pancreatic cancer risk.

RESULTS

Eleven discriminant metabolites were selected by applying a cut-off of 4.0 in XGBoost. Five SNP presented significance in metabolite-GWAS (p ≤ 5 × 10-6) and logistic regression analysis. Among them, the pair metabolite of rs2370981, rs55870181, and rs72805402 displayed a different network pattern with clinical/biochemical indicators on comparison with allelic carrier and non-carrier. In addition, we demonstrated the indirect effect of rs59519100 on pancreatic cancer risk mediated by γ-glutamyl tyrosine, which affects the smoking status. The predictive ability for pancreatic cancer on the model using five SNPs and four pair metabolites with the conventional risk factors was the highest (AUC: 0.738 [0.661-0.815]).

CONCLUSIONS

Signatures involving metabolites and SNPs discovered in the present research may be closely associated with the pathogenesis of pancreatic cancer and for use as predictive biomarkers allowing early pancreatic cancer diagnosis and therapy.

The role of diagnostic, prognostic, and predictive biomarkers in the management of early pancreatic cancer

Despite modern advances in cancer medicine, pancreatic cancer survival remains unchanged at just 12%. For the small proportion of patients diagnosed with 'early' (upfront or borderline resectable) disease, recurrences are common, and many recur soon after surgery. Whilst chemotherapy has been shown to increase survival in this cohort, the morbidity of surgery renders many candidates unsuitable for adjuvant treatment. Due to this, and the success of upfront chemotherapy in the advanced setting, use of neoadjuvant chemotherapy has been introduced in patients with upfront or borderline resectable disease. Randomized controlled trials have been conducted to compare upfront surgery to neoadjuvant chemotherapy in this patient cohort, opinions on the ideal upfront treatment approach are divided. This lack of consensus has highlighted the need for biomarkers to assist in clinical decision making. This review analyses the potential diagnostic, prognostic and predictive biomarkers that may assist in the diagnosis and management of early (upfront and borderline resectable) pancreatic cancer.

Targeting miRNA and using miRNA as potential therapeutic options to bypass resistance in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with poor prognosis due to early metastasis, low diagnostic rates at early stages, and resistance to current therapeutic regimens. Despite numerous studies and clinical trials, the mortality rate for PDAC has shown limited improvement. Therefore, there is a pressing need to attain. a more comprehensive molecular characterization to identify biomarkers enabling early detection and evaluation of treatment response. MicroRNA (miRNAs) are critical regulators of gene expression on the post-transcriptional level, and seem particularly interesting as biomarkers due to their relative stability, and the ability to detect them in fixed tissue specimens and biofluids. Deregulation of miRNAs is common and affects several hallmarks of cancer and contribute to the oncogenesis and metastasis of PDAC. Unique combinations of upregulated oncogenic miRNAs (oncomiRs) and downregulated tumor suppressor miRNAs (TsmiRs), promote metastasis, characterize the tumor and interfere with chemosensitivity of PDAC cells. Here, we review several oncomiRs and TsmiRs involved in chemoresistance to gemcitabine and FOLFIRINOX in PDAC and highlighted successful/effective miRNA-based therapy approaches in vivo. Integrating miRNAs in PDAC treatment represents a promising therapeutic avenue that can be used as guidance for personalized medicine for PDAC patients.

miRNAs orchestration of gallbladder cancer - Particular emphasis on diagnosis, progression and drug resistance

Gallbladder cancer (GBC) is characterized by a highly invasive nature and a poor prognosis, with adenocarcinoma being the main histological subtype. According to statistical data, patients diagnosed with advanced GBC have a survival rate of less than 5% for 5 years. Despite the novel therapeutic techniques, the unsatisfactory results could be related to the underlying biology of tumor cells and resistance to chemotherapy. Early diagnosis is more important than clinical therapy as it assists in determining the pathological stage of cancer and facilitates the selection of appropriate medication. Hence, it is very important to understand the precise pathogenesis of GBC and to discover potential novel biomarkers for early diagnosis of GBC. Non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, have been found to influence the transcriptional regulation of target genes associated with cancer, either directly or indirectly. microRNAs are a group of small, non-coding, single-stranded RNAs that are expressed endogenously. miRNAs play significant roles in various fundamental cellular processes. Therefore, miRNAs have the potential to serve as valuable biomarkers and therapeutic targets for GBC.

Noncoding RNAs: an emerging modulator of drug resistance in pancreatic cancer

Pancreatic cancer is the eighth leading cause of cancer-related deaths worldwide. Chemotherapy including gemcitabine, 5-fluorouracil, adriamycin and cisplatin, immunotherapy with immune checkpoint inhibitors and targeted therapy have been demonstrated to significantly improve prognosis of pancreatic cancer patients with advanced diseases. However, most patients developed drug resistance to these therapeutic agents, which leading to shortened patient survival. The detailed molecular mechanisms contributing to pancreatic cancer drug resistance remain largely unclear. The growing evidences have shown that noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), are involved in pancreatic cancer pathogenesis and development of drug resistance. In the present review, we systematically summarized the new insight on of various miRNAs, lncRNAs and circRNAs on drug resistance of pancreatic cancer. These results demonstrated that targeting the tumor-specific ncRNA may provide novel options for pancreatic cancer treatments.

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.

The Future of Biomarkers in Veterinary Medicine: Emerging Approaches and Associated Challenges

Simple Summary

In this review we seek to outline the role of new technologies in biomarker discovery, particularly within the veterinary field and with an emphasis on ‘omics’, as well as to examine why many biomarkers-despite much excitement-have not yet made it to clinical practice. Further we emphasise the critical need for close collaboration between clinicians, researchers and funding bodies and the need to set clear goals for biomarker requirements and realistic application in the clinical setting, ensuring that biomarker type, method of detection and clinical utility are compatible, and adequate funding, time and sample size are available for all phases of development.

Abstract

New biomarkers promise to transform veterinary practice through rapid diagnosis of diseases, effective monitoring of animal health and improved welfare and production efficiency. However, the road from biomarker discovery to translation is not always straightforward. This review focuses on molecular biomarkers under development in the veterinary field, introduces the emerging technological approaches transforming this space and the role of ‘omics platforms in novel biomarker discovery. The vast majority of veterinary biomarkers are at preliminary stages of development and not yet ready to be deployed into clinical translation. Hence, we examine the major challenges encountered in the process of biomarker development from discovery, through validation and translation to clinical practice, including the hurdles specific to veterinary practice and to each of the ‘omics platforms–transcriptomics, proteomics, lipidomics and metabolomics. Finally, recommendations are made for the planning and execution of biomarker studies with a view to assisting the success of novel biomarkers in reaching their full potential.

Hydrogel Nanoarchitectonics: An Evolving Paradigm for Ultrasensitive Biosensing

The integration of nanoarchitectonics and hydrogel into conventional biosensing platforms offers the opportunities to design physically and chemically controlled and optimized soft structures with superior biocompatibility, better immobilization of biomolecules, and specific and sensitive biosensor design. The physical and chemical properties of 3D hydrogel structures can be modified by integrating with nanostructures. Such modifications can enhance their responsiveness to mechanical, optical, thermal, magnetic, and electric stimuli, which in turn can enhance the practicality of biosensors in clinical settings. This review describes the synthesis and kinetics of gel networks and exploitation of nanostructure-integrated hydrogels in biosensing. With an emphasis on different integration strategies of hydrogel with nanostructures, this review highlights the importance of hydrogel nanostructures as one of the most favorable candidates for developing ultrasensitive biosensors. Moreover, hydrogel nanoarchitectonics are also portrayed as a promising candidate for fabricating next-generation robust biosensors.

Cancer-Associated Fibroblasts Confer Gemcitabine Resistance to Pancreatic Cancer Cells through PTEN-Targeting miRNAs in Exosomes

Simple Summary

Previous studies have shown that cancer associated fibroblasts exposed to chemotherapy release exosomes which promote chemoresistance in recipient cells. However, the molecular mechanism responsible for this has not been fully elucidated. In this study, we found that gemcitabine treatment caused fibroblasts to release exosome which contain PTEN-targeting miRNAs. These findings shed light on how fibroblasts exposed to chemotherapy promote tumor growth and drug resistance.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer-related death in the United States. Even though the poor prognosis of PDAC is often attributed to late diagnosis, patients with an early diagnosis who undergo tumor resection and adjuvant chemotherapy still show tumor recurrence, highlighting a need to develop therapies which can overcome chemoresistance. Chemoresistance has been linked to the high expression of microRNAs (miRs), such as miR-21, within tumor cells. Tumor cells can collect miRs through the uptake of miR-containing lipid extracellular vesicles called exosomes. These exosomes are secreted in high numbers from cancer-associated fibroblasts (CAFs) within the tumor microenvironment during gemcitabine treatment and can contribute to cell proliferation and chemoresistance. Here, we show a novel mechanism in which CAF-derived exosomes may promote proliferation and chemoresistance, in part, through suppression of the tumor suppressor PTEN. We identified five microRNAs: miR-21, miR-181a, miR-221, miR-222, and miR-92a, that significantly increased in number within the CAF exosomes secreted during gemcitabine treatment which target PTEN. Furthermore, we found that CAF exosomes suppressed PTEN expression in vitro and that treatment with the exosome inhibitor GW4869 blocked PTEN suppression in vivo. Collectively, these findings highlight a mechanism through which the PTEN expression loss, often seen in PDAC, may be attained and lend support to investigations into the use of exosome inhibitors as potential therapeutics to improve the effectiveness of chemotherapy.

MicroRNA-21 as a diagnostic and prognostic biomarker of lung cancer: a systematic review and meta-analysis

BACKGROUND

The relationship between microRNA-21 (miRNA-21) and pathogenesis of lung cancer is a considerable focus of research interest. However, to our knowledge, no in-depth meta-analyses based on existing evidence to ascertain the value of miRNA-21 in diagnosis and clinical prognosis of lung cancer have been documented.

METHODS

We comprehensively searched all the literature pertaining to 'miRNA-21' and 'lung cancer' from four databases from the period of inception of each database until May 2020. Using specific inclusion and exclusion criteria, the literature for inclusion was identified and the necessary data extracted.

RESULTS

In total, 46 articles were included in the meta-analysis, among which 31 focused on diagnostic value and 15 on prognostic value. Combined sensitivity (SEN) of miRNA-21 in diagnosis of lung cancer was 0.77 (95% confidence interval (CI): 0.72-0.81), specificity (SPE) was 0.86 (95% CI: 0.80-0.90), diagnostic odds ratio (DOR) was (95% CI: 12-33), and area under the SROC curve (AUC) was 0.87 (95% CI: 0.84-0.90). No significant correlations were observed between abnormal expression of miRNA-21 and gender, smoking habits, pathological type and clinical stage of lung cancer (P>0.05). In terms of overall survival (OS), univariate analysis (hazards ratio (HR) = 1.49, 95% CI: 1.22-1.82) revealed high expression of miRNA-21 as an influencing factor for lung cancer. MiRNA-21 was confirmed as an independent risk factor for poor prognosis in multivariate analysis (HR = 1.65, 95% CI: 1.24-2.19).

CONCLUSION

MiRNA-21 has potential clinical value in the diagnosis and prognosis of lung cancer and may serve as an effective diagnostic marker and therapeutic target in the future.

Predictive Biomarkers for a Personalized Approach in Resectable Pancreatic Cancer

The mainstay treatment for patients with immediate resectable pancreatic cancer remains upfront surgery, which represents the only potentially curative strategy. Nevertheless, the majority of patients surgically resected for pancreatic cancer experiences disease relapse, even when a combination adjuvant therapy is offered. Therefore, aiming at improving disease free survival and overall survival of these patients, there is an increasing interest in evaluating the activity and efficacy of neoadjuvant and perioperative treatments. In this view, it is of utmost importance to find biomarkers able to select patients who may benefit from a preoperative therapy rather than upfront surgical resection. Defined genomic alterations and a dynamic inflammatory microenvironment are the major culprits for disease recurrence and resistance to chemotherapeutic treatments in pancreatic cancer patients. Signal transduction pathways or tumor immune microenvironment could predict early recurrence and response to chemotherapy. In the last decade, distinct molecular subtypes of pancreatic cancer have been described, laying the bases to a tailored therapeutic approach, started firstly in the treatment of advanced disease. Patients with homologous repair deficiency, in particular with mutant germline BRCA genes, represent the first subgroup demonstrating to benefit from specific therapies. A fraction of patients with pancreatic cancer could take advantage of genome sequencing with the aim of identifying possible targetable mutations. These genomic driven strategies could be even more relevant in a potentially curative setting. In this review, we outline putative predictive markers that could help in the next future in tailoring the best therapeutic strategy for pancreatic cancer patients with a potentially curable disease.

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.

The Role of Circulating MicroRNAs in Patients with Early-Stage Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is increasing in incidence and is still associated with a high rate of mortality. Only a minority of patients are diagnosed in the early stage. Radical surgery is the only potential curative procedure. However, radicality is reached in 20% of patients operated on. Despite the multidisciplinary approach in resectable tumors, early tumor recurrences are common. Options on how to select optimal candidates for resection remain limited. Nevertheless, accumulating evidence shows an important role of circulating non-coding plasma and serum microRNAs (miRNAs), which physiologically regulate the function of a target protein. miRNAs also play a crucial role in carcinogenesis. In PDAC patients, the expression levels of certain miRNAs vary and may modulate the function of oncogenes or tumor suppressor genes. As they can be detected in a patient's blood, they have the potential to become promising non-invasive diagnostic and prognostic biomarkers. Moreover, they may also serve as markers of chemoresistance. Thus, miRNAs could be useful for early and accurate diagnosis, prognostic stratification, and individual treatment planning. In this review, we summarize the latest findings on miRNAs in PDAC patients, focusing on their potential use in the early stage of the disease.

Recent Advances in Pancreatic Cancer: Novel Prognostic Biomarkers and Targeted Therapy-A Review of the Literature

Pancreatic adenocarcinoma carries a devastating prognosis. For locally advanced and metastatic disease, several chemotherapeutic regimens are currently being used. Over the past years, novel approaches have included targeting EGFR, NTRK, PARP, K-Ras as well as stroma and fibrosis, leading to approval of NTRK and PARP inhibitors. Moreover, immune check point inhibitors and different combinational approaches involving immunotherapeutic agents are being investigated in many clinical trials. MiRNAs represent a novel tool and are thought to greatly improve management by allowing for earlier diagnosis and for more precise guidance of treatment.

miR-155, miR-21, and let-7a Expressions in MCF-10A and MCF-7 Cell Lines after Low to High Dose Irradiation

OBJECTIVE

Ionizing radiation is a tremendous risk factor for cancer development. MicroRNAs (miRNAs) are regulators that utilize cell pathways, which are implicated in human cancer prognosis. In addition, miRNAs respond to anti-cancer therapy and proliferation after irradiation. However, the changes in miRNA expression profiles in response to irradiation have not been comprehensively analysed. The present study was designed to assess potential changes that occur in miRNA expression following irradiation.

MATERIALS AND METHODS

In this experimental study, we used quantitative real-time polymerase chain reaction (qRTPCR) to measure the expressions of miR-155, miR-21, and let-7a in MCF-10A (normal breast cells) and MCF-7 (breast cancer cells) six hours after the cells were exposed to five different irradiation doses (50, 100, 400, 2000, and 4000 mGY).

RESULTS

After irradiation from the low to high doses, we observed an upsurge in miR-155 (more than 100%) expression and reduction in let-7a (more than 87%) expression. However, there was an increase and a reduction in miR-21 expression (more than 100%).

CONCLUSION

Irradiation can play an important role in cancer development in normal breast cells (MCF-10A) at low dose irradiation. However, the results showed little difference at high doses of radiation.

The Role of microRNA in Pancreatic Cancer

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

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.

Precision Oncology, Signaling and Anticancer Agents in Cancer Therapeutics

BACKGROUND

The global alliance for genomics and healthcare facilities provides innovational solutions to expedite research and clinical practices for complex and incurable health conditions. Precision oncology is an emerging field explicitly tailored to facilitate cancer diagnosis, prevention and treatment based on patients' genetic profile. Advancements in "omics" techniques, next-generation sequencing, artificial intelligence and clinical trial designs provide a platform for assessing the efficacy and safety of combination therapies and diagnostic procedures.

METHOD

Data were collected from Pubmed and Google scholar using keywords: "Precision medicine", "precision medicine and cancer", "anticancer agents in precision medicine" and reviewed comprehensively.

RESULTS

Personalized therapeutics including immunotherapy, cancer vaccines, serve as a groundbreaking solution for cancer treatment. Herein, we take a measurable view of precision therapies and novel diagnostic approaches targeting cancer treatment. The contemporary applications of precision medicine have also been described along with various hurdles identified in the successful establishment of precision therapeutics.

CONCLUSION

This review highlights the key breakthroughs related to immunotherapies, targeted anticancer agents, and target interventions related to cancer signaling mechanisms. The success story of this field in context to drug resistance, safety, patient survival and in improving quality of life is yet to be elucidated. We conclude that, in the near future, the field of individualized treatments may truly revolutionize the nature of cancer patient care.

The clinical significance of Notch1 immunoexpression in Caucasian patients with colorectal adenocarcinoma

Introduction

Colorectal cancer (CRC) is traditionally regarded as the most commonly diagnosed gastrointestinal malignant disease. Nevertheless, despite advances in diagnosis and novel therapeutic options, the clinical outcomes of patients are still not satisfactory.

Aim

To investigate the clinicopathological and prognostic roles of Notch1 expression, the immunohistochemical investigation was performed in samples of CRC tumour tissues, adjacent non-pathological mucosa, and metastatic foci in regional lymph nodes in Caucasian patients.

Material and methods

Paraffin-embedded adenocarcinoma samples were assessed immunohistochemically for Notch1 protein and scored according to the percentage of cells with a positive reaction combined with staining intensity. Connections between Notch1 immunoexpression and clinicopathological factors including the 5-year overall survival (OS) were evaluated.

Results

The level of the Notch1 immunohistochemical reactivity was correlated with the grade of the histological differentiation, size of the primary tumour, regional lymph node involvement, and perineural invasion (all p < 0.001). Kaplan-Meier survival analysis showed that the survival time for patients with a low expression of Notch1 was significantly longer than that for patients with moderate or strong level of Notch1 immunoreactivity (p < 0.001).

Conclusions

The enhanced level of Notch1 immunoexpression was significantly associated with malignancy-related clinicopathological factors and reduced the 5-year overall survival in CRC patients.

Overcoming negative predictions of microRNA expressions to gemcitabine response with FOLFIRINOX in advanced pancreatic cancer patients

FOLFIRINOX is superior to gemcitabine in patients with pancreatic cancer, but this regimen is associated with toxicity and biomarkers for response are warranted. MicroRNAs can mediate drug resistance and could provide predictive information. Altered expressions of several microRNAs including miR-21-5p, miR-10b-5p and miR-34a-5p have been previously linked to a worse response to gemcitabine. We investigated the influence of expression levels in tumor tissue of those three microRNAs on outcome to FOLFIRINOX. Twenty-nine patients with sufficient formalin-fixed paraffin-embedded tumor tissue were identified. There was no significant association between high and low expression groups for these three microRNA. We conclude that polychemotherapy combination can overcome intrinsic negative prognostic factors.

Non-coding RNA biomarkers in pancreatic ductal adenocarcinoma

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

Could Protons and Carbon Ions Be the Silver Bullets Against Pancreatic Cancer?

Pancreatic cancer is a very aggressive cancer type associated with one of the poorest prognostics. Despite several clinical trials to combine different types of therapies, none of them resulted in significant improvements for patient survival. Pancreatic cancers demonstrate a very broad panel of resistance mechanisms due to their biological properties but also their ability to remodel the tumour microenvironment. Radiotherapy is one of the most widely used treatments against cancer but, up to now, its impact remains limited in the context of pancreatic cancer. The modern era of radiotherapy proposes new approaches with increasing conformation but also more efficient effects on tumours in the case of charged particles. In this review, we highlight the interest in using charged particles in the context of pancreatic cancer therapy and the impact of this alternative to counteract resistance mechanisms.

MicroRNA's - The vibrant performers in the oral cancer scenario

MicroRNAs (miRNAs) are a family of small non-coding (18–22 nucleotide) RNA molecules. These molecules regulate gene expression by either inhibiting mRNA translation or by degrading mRNA. A single miRNA can control the expression of target genes, and the expression of a target gene can be regulated by multiple miRNAs. They are key regulators of various biological and pathological processes. These include cell proliferation, development and tumorigenesis. Novel studies have discovered definite signature miRNAs in the initiation and progression of cancers. Interestingly, miRNAs have also been found in fragile genomic sites that are associated with increased cancer risk.

These micro RNAs regulate the expression of several genes that play a crucial role in the transition of normal oral mucosa through dysplasia to malignancy. The aim of this review is to recapitulate the current understanding of the many miRNAs that have been identified, the genes that they target and the role that they play in the carcinogenic pathway. The review also highlights the prospective role of miRNAs in the diagnosis, prognosis and treatment of oral cancers.

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.

Clinical Theragnostic Potential of Diverse miRNA Expressions in Prostate Cancer: A Systematic Review and Meta-Analysis

Background: Prostate cancer (PrC) is the second-most frequent cancer in men, its incidence is emerging globally and is the fifth leading cause of death worldwide. While diagnosis and prognosis of PrC have been studied well, the associated therapeutic biomarkers have not yet been investigated comprehensively. This systematic review and meta-analysis aim to evaluate the theragnostic effects of microRNA expressions on chemoresistance in prostate cancer and to analyse the utility of miRNAs as clinical theragnostic biomarkers. Methods: A systematic literature search for studies reporting miRNA expressions and their role in chemoresistance in PrC published until 2018 was collected from bibliographic databases. The evaluation of data was performed as per PRISMA guidelines for systematic review and meta-analysis. Meta-analysis was performed using a random-effects model using Comprehensive Meta-Analysis (CMA) software. Heterogeneity between studies was analysed using Cochran’s Q test, I² and the Tau statistic. Quality assessment of the studies was performed using the Newcastle–Ottawa Scale (NOS) for the methodological assessment of cohort studies. Publication bias was assessed using Egger’s bias indicator test, Orwin and classic fail-safe N test, Begg and Mazumdar rank collection test, and Duval and Tweedie’s trim and fill methods. Findings: Out of 2909 studies retrieved, 79 studies were shortlisted and reviewed. A total of 17 studies met our eligibility criteria, from which 779 PrC patients and 17 chemotherapy drugs were examined, including docetaxel and paclitaxel. The majority of the drug regulatory genes reported were involved in cell survival, angiogenesis and cell proliferation pathways. We studied 42 miRNAs across all studies, out of which two miRNAs were found to be influencing chemosensitivity, while 21 were involved in chemoresistance. However, the remaining 19 miRNAs did not appear to have any theragnostic effects. Besides, the prognostic impact of the miRNAs was evaluated and had a pooled HR value of 1.960 with 95% CI (1.377–2.791). Interpretation: The observation of the current study depicts the significance of miRNA expression as a theragnostic biomarker in medical oncology. This review suggests the involvement of specific miRNAs as predictors of chemoresistance and sensitivity in PrC. Hence, the current systematic review and meta-analysis provide insight on the use of miRNA as PrC biomarkers, which can be harnessed as molecular candidates for therapeutic targeting.

MicroRNA-375-3p enhances chemosensitivity to 5-fluorouracil by targeting thymidylate synthase in colorectal cancer

Resistance to chemotherapy is a major challenge for the treatment of patients with colorectal cancer (CRC). Previous studies have found that microRNAs (miRNAs) play key roles in drug resistance; however, the role of miRNA‐373‐3p (miR‐375‐3p) in CRC remains unclear. The current study aimed to explore the potential function of miR‐375‐3p in 5‐fluorouracil (5‐FU) resistance. MicroRNA‐375‐3p was found to be widely downregulated in human CRC cell lines and tissues and to promote the sensitivity of CRC cells to 5‐FU by inducing colon cancer cell apoptosis and cycle arrest and by inhibiting cell growth, migration, and invasion in vitro. Thymidylate synthase (TYMS) was found to be a direct target of miR‐375‐3p, and TYMS knockdown exerted similar effects as miR‐375‐3p overexpression on the CRC cellular response to 5‐FU. Lipid‐coated calcium carbonate nanoparticles (NPs) were designed to cotransport 5‐FU and miR‐375‐3p into cells efficiently and rapidly and to release the drugs in a weakly acidic tumor microenvironment. The therapeutic effect of combined miR‐375 + 5‐FU/NPs was significantly higher than that of the individual treatments in mouse s.c. xenografts derived from HCT116 cells. Our results suggest that restoring miR‐375‐3p levels could be a future novel therapeutic strategy to enhance chemosensitivity to 5‐FU.

Comparison of Native Aspirates and Cytological Smears Obtained by EUS-Guided Biopsies for Effective DNA/RNA Marker Testing in Pancreatic Cancer

We compare two types of pancreatic carcinoma samples obtained by EUS-guided fine needle biopsy (EUS-FNB) in terms of the success rates and clinical validity of analysis of two most commonly investigated DNA/RNA pancreatic cancer markers, KRAS mutations and miR-21 expression. 118 patients with pancreatic ductal adenocarcinoma underwent EUS-FNB. The collected sample was divided, one part was stored in a stabilizing solution as native aspirate (EUS-FNA) and second part was processed into the cytological smear (EUS-FNC). DNA/RNA extraction was followed by analysis of KRAS mutations and miR-21 expression. For both sample types, the yields of DNA/RNA extraction and success rates of KRAS mutation and miRNA expression were evaluated. Finally, the resulting KRAS mutation frequency and miR-21 prognostic role were compared to literature data from tissue resections. The overall amount of isolated DNA/RNA from EUS-FNC was lower compared to the EUS-FNA, average yield 10 ng vs 147 ng for DNA and average yield 164 vs. 642 ng for RNA, but the success rates for KRAS and miR-21 analysis was 100% for both sample types. The KRAS-mutant detection frequency in EUS-FNC was 12% higher than in EUS-FNA (90 vs 78%). The prognostic role of miR-21 was confirmed in EUS-FNC (p = 0.02), but did not reach statistical significance in EUS-FNA (p = 0.06). Although both types of EUS-FNB samples are suitable for DNA/RNA extraction and subsequent DNA mutation and miRNA expression analysis, reliable results with clinical validity were only obtained for EUS-FNC.

Markers of pancreatic cancer stem cells and their clinical and therapeutic implications

Pancreatic cancer (PC) is the fourth most common cause of death among all cancers. Poor prognosis of PC may be caused by a prevalence of cancer stem cells (CSCs). CSCs are a population of cancer cells showing stem cell-like characteristics. CSCs have the ability to self-renew and may initiate tumorigenesis. PC CSCs express markers such as CD133, CD24, CD44, DCLK1, CXCR4, ESA, Oct4 and ABCB1. There is a wide complexity of interaction and relationships between CSC markers in PC. These markers are negative prognostic factors and are connected with tumor recurrence and clinical progression. Additionally, PC CSCs are resistant to treatment with gemcitabine. Thus, most current therapies for PC are ineffective. Numerous studies have shown, that targeting of these proteins may increase both disease-free and overall survival in PC.

New avenues in pancreatic cancer: exploiting microRNAs as predictive biomarkers and new approaches to target aberrant metabolism

Introduction: Most pancreatic cancer patients are diagnosed at advanced-stages and first-line regimens (FOLFIRINOX and gemcitabine/nab-paclitaxel) provide limited survival advantage and are associated with considerable toxicities. In this grim scenario, novel treatments and biomarkers are warranted.Areas covered: MicroRNAs (miRNAs) emerged as biomarkers for cancer prognosis and chemoresistance and blood-based miRNAs are being evaluated as indicators of therapeutic activity. Moreover, aberrant metabolism, such as aerobic glycolysis, has been correlated to tumor aggressiveness and poor prognosis. Against this background, innovative approaches to tackle metabolic aberrations are being implemented and glycolytic inhibitors targeting lactate dehydrogenase-A (LDH-A) showed promising effects in preclinical models. A PubMed search was used to compile relevant publications until February 2019.Expert opinion: Analysis of tissue/circulating miRNA might improve selection for optimal treatment regimens. For instance, miR-181a modulation seems to predict response to FOLFIRINOX. However, we need further studies to validate predictive miRNA profiles, as well as to exploit miRNAs for treatment-tailoring. Several miRNAs have also a key role in regulating metabolic aberrations. Since preliminary evidence supports the development of new agents targeting these aberrations, such as LDH-A inhibitors, the identification of biomarkers for these treatments, including the above-mentioned miRNAs, should shorten the gap between preclinical studies and personalized therapies.

Development of microRNA-based therapy for pancreatic cancer

Despite extensive research efforts on diagnosis and treatment, pancreatic ductal adenocarcinoma (PDAC) remains a devastating disease and the third leading cause of cancer-related death in the United States. Resistance to current therapeutic approaches is a major reason for the poor survival of pancreatic patients. In order to overcome this major challenge and improve patient outcomes, we are in desperate need of novel therapeutic approaches. PDAC chemoresistance mechanisms are complex and multifaceted. Novel therapeutics must be equipped to deal with this challenge. microRNAs (miRNAs) have emerged as strong candidates to fill this role due to their multitargeted function. miRNAs have been shown to have important roles in pancreatic cancer resistance. In this review, we summarize the recent advancement in miRNA research related to PDAC therapeutic resistance mechanisms and the potential of miRNAs as therapeutic agents for future clinical management of PDAC.

Epithelial-mesenchymal plasticity-engaging stemness in an interplay of phenotypes

Cancer is a genetic disease which results in a functional imbalance between tumour-repressive and oncogenic signals. The WHO highlights the burden of this indomitable disease, listing it as the second leading cause of death globally. The major cause of cancer-related death is rarely the effect of the primary tumour itself, but rather, the devastating spread of cancer cells in metastases. Epithelial-mesenchymal plasticity (EMP)-termed as the ability of cells to maintain its plasticity and transit between epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) states-plays a fundamental role in cancer metastasis. These cell transitions allow them migrate from the primary tumour and invade the secondary site. EMP is associated with migration, invasion, colonisation, self-renewal and drug resistance. This review briefly elucidates the mechanism of EMP and the association between cancer stem cells (CSCs) and circulating tumour cells (CTCs), biomarkers and signalling pathways involved in EMP as well as drug resistance and therapeutic targeting.

Therapeutic Perspectives of Molecules from Urtica dioica Extracts for Cancer Treatment

A large range of chronic and degenerative diseases can be prevented through the use of food products and food bioactives. This study reports the health benefits and biological activities of the Urtica dioica (U. dioica) edible plant, with particular focus on its cancer chemopreventive potential. Numerous studies have attempted to investigate the most efficient anti-cancer therapy with few side effects and high toxicity on cancer cells to overcome the chemoresistance of cancer cells and the adverse effects of current therapies. In this regard, natural products from edible plants have been assessed as sources of anti-cancer agents. In this article, we review current knowledge from studies that have examined the cytotoxic, anti-tumor and anti-metastatic effects of U. dioica plant on several human cancers. Special attention has been dedicated to the treatment of breast cancer, the most prevalent cancer among women and one of the main causes of death worldwide. The anti-proliferative and apoptotic effects of U. dioica have been demonstrated on different human cancers, investigating the properties of U. dioica at cellular and molecular levels. The potent cytotoxicity and anti-cancer activity of the U. dioica extracts are due to its bioactive natural products content, including polyphenols which reportedly possess anti-oxidant, anti-mutagenic and anti-proliferative properties. The efficacy of this edible plant to prevent or mitigate human cancers has been demonstrated in laboratory conditions as well as in experimental animal models, paving the way to the development of nutraceuticals for new anti-cancer therapies.

miRNA Predictors of Pancreatic Cancer Chemotherapeutic Response: A Systematic Review and Meta-Analysis

BACKGROUND

pancreatic cancer (PC) has increasing incidence and mortality in developing countries, and drug resistance is a significant hindrance to the efficacy of successful treatment. The objective of this systematic review and meta-analysis was to evaluate the association between miRNAs and response to chemotherapy in pancreatic cancer patients.

METHODS

the systematic review and meta-analysis was based on articles collected from a thorough search of PubMed and Science Direct databases for publications spanning from January 2008 to December 2018. The articles were screened via a set of inclusion and exclusion criteria based on the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. Data was extracted, collated and tabulated in MS Excel for further synthesis. Hazard ratio (HR) was selected as the effect size metric to be pooled across studies for the meta-analysis, with the random effects model being applied. Subgroup analysis was also conducted, and the presence of publication bias in the selected studies was assessed. Publication bias of the included studies was quantified.

FINDINGS

of the 169 articles screened, 43 studies were included in our systematic review and 13 articles were included in the meta-analysis. Gemcitabine was observed to be the principal drug used in a majority of the studies. A total of 48 miRNAs have been studied, and 18 were observed to have possible contributions to chemoresistance, while 15 were observed to have possible contributions to chemosensitivity. 41 drug-related genetic pathways have been identified, through which the highlighted miRNA may be affecting chemosensitivity/resistance. The pooled HR value for overall survival was 1.603; (95% Confidence Interval (CI) 1.2-2.143; p-value: 0.01), with the subgroup analysis for miR-21 showing HR for resistance of 2.061; 95% CI 1.195-3.556; p-value: 0.09.

INTERPRETATION

our results highlight multiple miRNAs that have possible associations with modulation of chemotherapy response in pancreatic cancer patients. Further studies are needed to discover the molecular mechanisms underlying these associations before they can be suggested for use as biomarkers of response to chemotherapeutic interventions in pancreatic cancer.

The emerging role of liquid biopsy in diagnosis, prognosis and treatment monitoring of pancreatic cancer

Circulating tumor DNA, circulating tumor cells and tumor-related exosomes may offer new opportunities to provide insights into the biological and clinical characteristics of a neoplastic disease. They represent alternative routes for diagnostic and prognostic purposes, and for predicting and longitudinally monitoring response to treatment and disease progression. Hence, circulating biomarkers represent promising noninvasive tools in the scenario of pancreatic cancer, where neither molecular nor clinical predictors of treatment benefit have been identified yet. This review aims to provide an overview of the current status of circulating biomarker research in pancreatic cancer, and discusses their potential clinical utility to facilitate clinical decision-making.

Potential four‑miRNA signature associated with T stage and prognosis of patients with pancreatic ductal adenocarcinoma identified by co‑expression analysis

With a 5‑year survival rate of only 8%, pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer‑associated mortality worldwide. Unfortunately, even following radical surgery, patient outcomes remain poor. Emerging as a new class of biomarkers in human cancer, microRNAs (miRNAs/miRs) have been reported to have various tumor suppressor and oncogenic functions. In the present study, miRNA expression profiles of patients with PDAC and corresponding clinical data with survival profiles were obtained from The Cancer Genome Atlas database. A co‑expression network was constructed to detect the modules significantly associated with clinical features by weighted gene co‑expression network analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on the hub miRNAs in the module of interest for functional annotation. A prognosis model consisting of hub miRNAs was generated using the R package 'rbsurv' and validated in survival analysis. The expression data of 523 miRNAs in 124 patients with PDAC were analyzed in a co‑expression network. The turquoise module containing 131 miRNAs was identified to be associated with pathological T stage (cor=‑0.21; P=0.02). The 39 hub miRNAs of the turquoise module were then detected using the 'networkScreening' function in R. These miRNAs were predominantly involved in biological processes including 'regulation of transcription', 'apoptotic process', 'TGF‑β receptor signaling pathway', 'Ras protein signal transduction' and significantly enriched in 'cell cycle', 'adherens junction', 'FoxO', 'Hippo' and 'PI3K‑Akt signaling' pathways. A prognostic signature consisting of four hub miRNAs (miR‑1197, miR‑218‑2, miR‑889 and miR‑487a) associated with pathological T stage was identified to stratify the patients with early‑stage PDAC into high and low risk groups. The signature may serve as a potential prognostic biomarker for patients with early‑stage PDAC who undergo radical resection.

Prognostic significance of circulating microRNA-21 expression in esophageal, pancreatic and colorectal cancers; a systematic review and meta-analysis

BACKGROUND

Literature has shown that aberrantly expressed microRNAs may have implications in certain cancers. A wealth of studies signal potential prognostic role of microRNA-21 in GIT cancers. This meta-analysis quantitatively determines prognostic significance of circulating microRNA-21 in esophageal squamous cell carcinoma (ESCC), pancreatic ductal adenocarcinoma (PDAC) and colorectal carcinoma (CRC).

METHODS

Databases of Medline, Wiley online library, Cochrane library, Taylor and Francis Online, CINAHL, Springer, Proquest, ISI Web of knowledge, ScienceDirect, and Emerald were searched using MeSH terms serum/tissue microRNA-21, prognosis, esophagus squamous cell carcinoma, pancreatic ductal adenocarcinoma, colorectal cancer. A systematic algorithm was used that selected 15 relevant studies. Meta-analysis was conducted using forest plot and a summary effect model was employed.

RESULTS

This meta-analysis reports significant prognostic value of miR-21 in predicting worse overall survival (OS) in ESCC, PDAC, and CRC with pooled hazard ratio (HR) of 3.49 (95% CI 2.58-4.71, p-value < 0.01). Subgroup analysis for ESCC showed a pooled HR of 3.46 (95% CI 1.88-635, p value of <0.01), worse overall survival (OS) with the pooled HR of 3.14 (95% CI 2.22-4.43, p value < 0.01) for CRC and a pooled HR of 3.77 (95% CI 1.63-8.73, p value < 0.01) for PDAC.

CONCLUSION

This research infers that microRNA-21 expression is a powerful prognostic tool. Expression of micro-RNA-21 is associated with poor OS and poorer disease-free survival in ESCC, PDAC and CRC.

Securidaca-saponins are natural inhibitors of AKT, MCL-1, and BCL2L1 in cervical cancer cells

Introduction

Scientific research is beginning to prove the connection between claims by African traditional medicine and the natural chemical specifics contained in medicinal plant Securidaca longipedunculata. Our previous studies showed that two natural saponin fractions (4A3 and 4A4) identified in the plant as triterpenoid glycosides are capable of activating apoptosis on cervical tumor cell lines. Considering this and some critical roles of human papillomavirus (HPV) E6 oncogene on cervical cells, by promoting carcinogenesis and cell survival, it became necessary to investigate the possible pathways for apoptosis transmission.

Methods

Tests conducted on relevant cervical tumor cell lines such as Caski and Bu25TK included the following: MTT assay; scratch assay (to determine cell migration/invasion); fluorescence microscopy with Annexin V–fluorescein isothiocyanate, muscle progenitor cell) and propidium iodide staining; and finally reverse transcriptase quantitative PCR (RT-qPCR) for gene analysis.

Results

Reduced cell proliferation was observed due to activities of 4A3 and 4A4 fractions, with half-maximal inhibitory concentration (IC₅₀) of 7.03 and 16.39 μg/mL, respectively, on Caski cell line. A significant reduction in cell migration occurred within 48 and 72 hours, respectively, for Caski and Bu25TK cell lines. Late apoptosis was activated by 4A3, staining both Annexin V and PI, in contrast to 4A4’s early apoptosis. RT-qPCR data revealed a fold change (FC) inhibition of antiapoptotic proteins such as MCL-1 and BCL2L1, with diminished level of AKT-3, VEGFA, MALAT1, etc. The expression of p53, proapoptotic BAD, and caspase-8 was nonsignificant.

Conclusion

The low expression of AKT-3 and antiapoptotic proteins (MCL-1 and BCL2L1), as well as VEGFA, could simply be an indication for possible suppression of cell survival mechanisms via multiple channels. We therefore conclude that 4A3 and 4A4 fractions mediate activity via the inhibition of phosphatidylinositol-3-OH kinase (PI3K)-AKT/mTOR/NF-kB-dependent antiapoptotic stimuli. Further studies are ongoing to reveal the chemical structures and compositions of these two fractions.

Pre-operative Plasma miR-21-5p Is a Sensitive Biomarker and Independent Prognostic Factor in Patients with Pancreatic Ductal Adenocarcinoma Undergoing Surgical Resection

Blood plasma microRNAs (miRNAs) are emerging as a clinically useful tool for non-invasive detection and prognosis estimation in various cancer types including pancreatic ductal adenocarcinoma (PDAC). The aim of the present study was to provide an independent validation of circulating miRNAs identified in previous studies as diagnostic and/or prognostic biomarkers in PDAC. Based on the literature search, 6 miRNAs were chosen as candidates for independent validation; miR-21-5p, miR-375, miR-155, miR-17-5p, miR-126-5p and miR-1290. Validation of these miRNAs was performed in a cohort of 25 patients with PDAC undergoing surgical resection and 24 healthy donors. Plasma levels of miRNAs were determined using quantitative real-time PCR. We confirmed significantly higher levels of all tested miRNA in blood plasma of PDAC patients in comparison to healthy controls with miR-21-5p showing the highest analytical performance (p<0.001; AUC>0.99). Increased levels of miR-21-5p (p=0.045) and miR-375 (p=0.013) were significantly associated with overall survival. Multivariate analysis demonstrated that miR-21-5p is a significant unfavorable prognostic factor independent on other clinical variables including adjuvant chemotherapy (hazard ratio 2.95; 95% CI 1.06-8.18; p=0.038). Our preliminary data indicate promising diagnostic and prognostic utility of plasma miR-21-5p in PDAC patients.

miR-185 suppresses progression of Ewing's sarcoma via inhibiting the PI3K/AKT and Wnt/β-catenin pathways

Background

miRNAs are confirmed to play essential roles in tumorigenesis and progression of cancers, including Ewing's sarcoma. miR-185 has been reported to be downregulated in some tumors, whereas the role of miR-185 in Ewing's sarcoma remains unclear.

Purpose

The objective of this study was to investigate the role of miR-185 in the progression and metastasis of Ewing's sarcoma and explore the associated mechanism.

Materials and methods

Ewing's sarcoma cell line RD-ES was transfected with pCMV-MIR-miR185 vector to upregulate the expression of miR-185. Cell Counting Kit 8 and colony formation assays were used to assess the effect of miR-185 on cell proliferation. The effect of miR-185 on cell migration and invasion was detected by transwell assay. Flow cytometry assay was performed to detect apoptosis rate of RD-ES cells. The protein levels of apoptosis-related proteins was determined using Western blot assay or immunohistochemistry assay. Dual-luciferase reporter assay was used to validate the regulation between miR-185 and its target gene.

Results

Upregulation of miR-185 caused significant inhibition on cell growth capacity, migration and invasion of Ewing's sarcoma cell RD-ES. Besides, upregulation of miR-185 was observed to accelerate cell apoptosis in a mitochondrial pathway through regulating Bcl-2/Bax, Caspase 3, and Caspase 9 in Ewing's sarcoma in vitro. Moreover, upregulation of miR-185 was found to suppress the PI3K/Akt/mTOR and Wnt/β-catenin pathways in RD-ES cells. Furthermore, we identified that E2F6 was a target gene for miR-185, and the suppression on cell proliferation caused by overexpression of miR-185 was significantly rescued by the upregulation of E2F6 in RD-ES cells.

Conclusion

miR-185 is involved in cell growth, motility and survival of Ewing's sarcoma as a tumor suppressor via suppressing PI3K/Akt/mTOR and Wnt/β-catenin pathways and targeting E2F6.

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.

MicroRNAs in pancreatic cancer diagnosis and therapy

Pancreatic cancer remains a disease with very poor prognosis (only 5-6% of patients are still alive after five years). Attempts to improve the results of treatment of pancreatic cancer focus on a better understanding of the pathogenesis, and non-invasive diagnostic methods (genetic testing from peripheral blood), which would create the possibility of early diagnosis and early surgical treatment before the onset of metastasis. New hopes for the improvement of early diagnosis and treatment of pancreatic ductal adenocarcinoma (PDAC) are associated with genetic testing of microRNA expression changes. A large body of evidence has revealed that microRNAs are aberrantly expressed in the serum and in cancer tissues and elicit oncogenic or tumour-suppressive functions. Selected microRNAs can distinguish pancreatic ductal adenocarcinoma from non-cancerous lesions of the pancreas. This review focuses on the involvement of microRNAs in the early diagnosis of pancreatic cancer. Research results related to the development of a novel therapeutic strategy based on the modulation of microRNA expressions for a better outcome in patients with pancreatic cancer are also presented.

ATP-binding cassette transporters in progression and clinical outcome of pancreatic cancer: What is the way forward?

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive diseases and is characterized by high chemoresistance, leading to the lack of effective therapeutic approaches and grim prognosis. Despite increasing understanding of the mechanisms of chemoresistance in cancer and the role of ATP-binding cassette (ABC) transporters in this resistance, the therapeutic potential of their pharmacological inhibition has not been successfully exploited yet. In spite of the discovery of potent pharmacological modulators of ABC transporters, the results obtained in clinical trials have been so far disappointing, with high toxicity levels impairing their successful administration to the patients. Critically, although ABC transporters have been mostly studied for their involvement in development of multidrug resistance (MDR), in recent years the contribution of ABC transporters to cancer initiation and progression has emerged as an important area of research, the understanding of which could significantly influence the development of more specific and efficient therapies. In this review, we explore the role of ABC transporters in the development and progression of malignancies, with focus on PDAC. Their established involvement in development of MDR will be also presented. Moreover, an emerging role for ABC transporters as prognostic tools for patients' survival will be discussed, demonstrating the therapeutic potential of ABC transporters in cancer therapy.

MiR-21 up-regulation in ampullary adenocarcinoma and its pre-invasive lesions

Poor information is available on the molecular landscape characterizing the carcinogenetic process leading to ampullary carcinoma. MiR-21 is one of the most frequently up-regulated miRNAs in pancreatic adenocarcinoma, a tumor sharing similar molecular features with ampullary adenocarcinomas (AVCs), above all with the pancreatic-biliary type. We profiled, by in situ hybridization (ISH), miR-21 expression in a series of 26 AVCs, 50 ampullary dysplastic lesions (35 low-grade [LG-IEN] and 15 high-grade [HG-IEN]) and 10 normal duodenal mucosa samples. The same series was investigated by immunohistochemistry for β-catenin, p53 and HER2 expression. HER2 gene amplification was evaluated by chromogenic in situ hybridization. To validate miR-21 ISH results we performed miR-21 qRT-PCR analysis in a series of 10 AVCs and their matched normal samples. All the normal control samples showed a negative or faint miR-21 expression, whereas a significant miR-21 up-regulation was observed during the carcinogenetic cascade (p < 0.001), with 21/26 (80.8%) of cancer samples showing a miR-21 overexpression. In comparison to control samples, a significant overexpression was found in samples of LG-IEN (p = .0003), HG-IEN (p = .0001), and AVCs (p < 0.0001). No significant difference in miR-21 overexpression was observed between LG-IEN, HG-IEN and AVCs. By qRT-PCR analysis, AVCs showed a 1.7-fold increase over the controls (p = .003). P53 was frequently dysregulated in both dysplastic and carcinoma samples (44 out of 76; 57.9%). A 20% (10/50) of dysplastic lesions and 11% (3/26) of carcinomas were characterized by a nuclear localization of β-catenin. Only 2 AVCs (7.7%; both intestinal-type) showed a HER2 overexpression (both 2+), which corresponded to a HER2 gene amplification at CISH analysis. This is the first study demonstrating a miRNA dysregulation in the whole spectrum of ampullary carcinogenesis. MiR-21 overexpression is an early molecular event during ampullary carcinogenesis and its levels increase with the neoplastic progression.