Association of microRNA-21 expression with its targets, PDCD4 and TIMP3, in pancreatic ductal adenocarcinoma

Current status and new directions for hepatocellular carcinoma diagnosis

Liver cancer ranks as the sixth most common cancer globally, with hepatocellular carcinoma (HCC) accounting for approximately 75%-85% of cases. Most patients present with moderately advanced disease, while those with advanced HCC face limited and ineffective treatment options. Despite diagnostic efforts, no ideal tumor marker exists to date, highlighting the urgent clinical need for improved early detection of HCC. A key research objective is the development of assays that target specific pathways involved in HCC progression. This review explores the pathological origin and development of HCC, providing insights into the mechanistic rationale, clinical statistics, and the advantages and limitations of commonly used diagnostic tumor markers. Additionally, it discusses the potential of emerging biomarkers for early diagnosis and offers a brief overview of relevant assay methodologies. This review aims to summarize existing markers and investigate new ones, providing a basis for subsequent research.

Molecular Targets for the Diagnosis and Treatment of Pancreatic Cancer

Pancreatic cancer is one of the most aggressive and lethal forms of cancer, with a five-year survival rate of less than 10%. Despite advances in treatment modalities, the prognosis for pancreatic cancer patients remains poor, highlighting the urgent need for innovative approaches for early diagnosis and targeted therapies. In recent years, there has been significant progress in understanding the molecular mechanisms underlying pancreatic cancer development and progression. This paper reviews the current knowledge of molecular targets for the diagnosis and treatment of pancreatic cancer.

Role of Angiogenesis and Its Biomarkers in Development of Targeted Tumor Therapies

Angiogenesis plays a significant role in the human body, from wound healing to tumor progression. "Angiogenic switch" indicates a time-restricted event where the imbalance between pro- and antiangiogenic factors results in the transition from prevascular hyperplasia to outgrowing vascularized tumor, which eventually leads to the malignant cancer progression. In the last decade, molecular players, i.e., angiogenic biomarkers and underlying molecular pathways involved in tumorigenesis, have been intensely investigated. Disrupting the initiation and halting the progression of angiogenesis by targeting these biomarkers and molecular pathways has been considered as a potential treatment approach for tumor angiogenesis. This review discusses the currently known biomarkers and available antiangiogenic therapies in cancer, i.e., monoclonal antibodies, aptamers, small molecular inhibitors, miRNAs, siRNAs, angiostatin, endostatin, and melatonin analogues, either approved by the U.S. Food and Drug Administration or currently under clinical and preclinical investigations.

Inflammation-Associated Cytotoxic Agents in Tumorigenesis

Chronic inflammatory processes are related to all stages of tumorigenesis. As inflammation is closely associated with the activation and release of different cytotoxic agents, the interplay between cytotoxic agents and antagonizing principles is highlighted in this review to address the question of how tumor cells overcome the enhanced values of cytotoxic agents in tumors. In tumor cells, the enhanced formation of mitochondrial-derived reactive species and elevated values of iron ions and free heme are antagonized by an overexpression of enzymes and proteins, contributing to the antioxidative defense and maintenance of redox homeostasis. Through these mechanisms, tumor cells can even survive additional stress caused by radio- and chemotherapy. Through the secretion of active agents from tumor cells, immune cells are suppressed in the tumor microenvironment and an enhanced formation of extracellular matrix components is induced. Different oxidant- and protease-based cytotoxic agents are involved in tumor-mediated immunosuppression, tumor growth, tumor cell invasion, and metastasis. Considering the special metabolic conditions in tumors, the main focus here was directed on the disturbed balance between the cytotoxic agents and protective mechanisms in late-stage tumors. This knowledge is mandatory for the implementation of novel anti-cancerous therapeutic approaches.

Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer

Cancer stem cells (CSCs), initially identified in leukemia in 1994, constitute a distinct subset of tumor cells characterized by surface markers such as CD133, CD44, and ALDH. Their behavior is regulated through a complex interplay of networks, including transcriptional, post-transcriptional, epigenetic, tumor microenvironment (TME), and epithelial-mesenchymal transition (EMT) factors. Numerous signaling pathways were found to be involved in the regulatory network of CSCs. The maintenance of CSC characteristics plays a pivotal role in driving CSC-associated tumor metastasis and conferring resistance to therapy. Consequently, CSCs have emerged as promising targets in cancer treatment. To date, researchers have developed several anticancer agents tailored to specifically target CSCs, with some of these treatment strategies currently undergoing preclinical or clinical trials. In this review, we outline the origin and biological characteristics of CSCs, explore the regulatory networks governing CSCs, discuss the signaling pathways implicated in these networks, and investigate the influential factors contributing to therapy resistance in CSCs. Finally, we offer insights into preclinical and clinical agents designed to eliminate CSCs.

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.

Microbiome and MicroRNA or Long Non-Coding RNA-Two Modern Approaches to Understanding Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of humans' most common and fatal neoplasms. Nowadays, a number of PDAC studies are being conducted in two different fields: non-coding RNA (especially microRNA and long non-coding RNA) and microbiota. It has been recently discovered that not only does miRNA affect particular bacteria in the gut microbiome that can promote carcinogenesis in the pancreas, but the microbiome also has a visible impact on the miRNA. This suggests that it is possible to use the combined impact of the microbiome and noncoding RNA to suppress the development of PDAC. Nevertheless, insufficient research has focused on bounding both approaches to the diagnosis, treatment, and prevention of pancreatic ductal adenocarcinoma. In this article, we summarize the recent literature on the molecular basis of carcinogenesis in the pancreas, the two-sided impact of particular types of non-coding RNA and the pancreatic cancer microbiome, and possible medical implications of the discovered phenomenon.

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.

The Roles of MicroRNA in Pancreatic Cancer Progression

Pancreatic Ductal Adenocarcinoma (PDAC) has a poor patient survival rate in comparison with other cancer types, even after targeted therapy, chemotherapy, and immunotherapy. Therefore, a great deal needs to be done to gain a better understanding of the biology and identification of prognostic and predictive markers for the development of superior therapies. The microRNAs (miRNAs) belong to small non-coding RNAs that regulate post-transcriptional gene expression. Several shreds of evidence indicate that miRNAs play an important role in the pathogenesis of pancreatic cancer. Here we review the recent developments in miRNAs and their target role in the development, metastasis, migration, and invasion.

Disease progression role as well as the diagnostic and prognostic value of microRNA-21 in patients with cervical cancer: A systematic review and meta-analysis

Introduction

Cervical cancer is the fourth commonest and the fourth leading cause of cancer death in females globally. The upregulated expression of microRNA-21 in cervical cancer has been investigated in numerous studies, yet given the inconsistency on some of the findings, a systematic review and meta-analysis is needed. Therefore, the aim of this systematic review and meta-analysis is to investigate the role in disease progression as well as the diagnostic and prognostic value of microRNA-21 in patients with cervical cancer.

Methods

Literature search was carried out through visiting several electronic databases including PubMed/MEDLINE/ PubMed Central, Web of Science, Embase, WorldCat, DOAJ, ScienceDirect, and Google Scholar. After extraction, data analysis was carried out using Rev-Man 5.3, STATA 15.0 and Meta-disk 1.4. I2 and meta-bias statistics assessed heterogeneity and publication bias of the included studies, respectively. The area under summary receiver operating characteristic curve and other diagnostic indexes were used to estimate diagnostic accuracy.

Result

A total of 53 studies were included for this systematic review and meta-analysis. This study summarized that microRNA-21 targets the expression of numerous genes that regulate their subsequent downstream signaling pathways which promote cervical carcinogenesis. The targets addressed in this study included TNF-α, CCL20, PTEN RasA1, TIMP3, PDCD-4, TPM-1, FASL, BTG-2, GAS-5, and VHL. In addition, the meta-analysis of reports from 6 eligible studies has demonstrated that the overall area under the curve (AUC) of summary receiver operating characteristic (SROC) of microRNA-21 as a diagnostic accuracy index for cervical cancer was 0.80 (95% CI: 0.75, 0.86). In addition, evidence from studies revealed that upregulated microRNA-21 led to worsening progression and poor prognosis in cervical cancer patients.

Conclusion

microRNA-21 is an oncogenic microRNA molecule playing a key role in the development and progression of cervical malignancy. It has good diagnostic accuracy in the diagnosis of cervical cancer. In addition, the upregulation of microRNA-21 could predict a worse outcome in terms of prognosis in cervical cancer patients.

Muscarinic receptor activation in colon cancer selectively augments pro-proliferative microRNA-21, microRNA-221 and microRNA-222 expression

Overexpression of M3 subtype muscarinic receptors (M3R) hastens colon cancer progression. As microRNA (miRNA) expression is commonly dysregulated in cancer, we used microarrays to examine miRNA profiles in muscarinic receptor agonist-treated human colon cancer cells. We used quantitative RT-PCR (qPCR) to validate microarray results and examine miRNA expression in colon cancers and adjacent normal colon. These assays revealed that acetylcholine (ACh) treatment robustly induced miR-222 expression; miR-222 levels were three-fold higher in cancer compared to normal colon. In kinetic studies, ACh induced a 4.6-fold increase in pri-miR-222 levels within 1 h, while mature miR-222 increased gradually to 1.8-fold within 4 h. To identify post-M3R signaling mediating these actions, we used chemical inhibitors and agonists. ACh-induced increases in pri-miR-222 were attenuated by pre-incubating cells with atropine and inhibitors of protein kinase C (PKC) and p38 MAPK. Treatment with a PKC agonist, phorbol 12-myristate 13-acetate, increased pri-miR-222 levels, an effect blocked by PKC and p38 MAPK inhibitors, but not by atropine. Notably, treatment with ACh or transfection with miR-222 mimics increased cell proliferation; atropine blocked the effects of ACh but not miR-222. These findings identify a novel mechanism whereby post-M3R PKC/p38 MAPK signaling stimulates miR-222 expression and colon cancer cell proliferation.

Protective effect of MiR-146 on renal injury following cardiopulmonary bypass in rats through mediating NF-κB signaling pathway

The mechanism of renal injury after cardiopulmonary bypass is not clear, and the protective effect of microRNA-146 through mediating NF KB signaling pathway needs to be verified. The study intends to establish a rat model of cardiopulmonary bypass (CPB). MiR-146 is silenced or overexpressed by lentivirus transfection. It is divided into miR-146 inhibitors group (inhibitors), miR-146 mimics group (mimics) and sham group. It is found that the contents of Cr, bun and MDA in blood = , serum IL-1, IL-6 and TNF in mimics group are higher than those in the other two groups- α Content, apoptosis rate, ICAM-1, TNF- α, NF- κ B mRNA and NF- κ B protein decreased significantly (P < 0.05), while the content of SOD in kidney increased significantly (P < 0.05). In the inhibitors group, the above indicators showed the opposite results. Double luciferase assay showed that NF-kB was the target gene of miR-146. It can be seen that the expression of miR-146 inhibits inflammatory factors, apoptosis, oxidative stress and NF- κ the activation of B pathway promotes the repair of renal injury in CPB rats.

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.

Low PDCD4 Expression Is Associated With Poor Prognosis of Colorectal Carcinoma

Programmed cell death 4 (PDCD4) is a tumor suppressor gene that inhibits tumor progression, invasion, and metastasis. Decreased PDCD4 expression is associated with poor prognosis in various types of cancers. We evaluated PDCD4 expression and its clinicopathologic correlation, including patient survival, in 289 surgically resected colorectal cancers. Low nuclear PDCD4 expression was identified in 177 (61.2%) cases and was associated with large tumor size, high pT classification, and the presence of lymphovascular and perineural invasion. The 5-year survival rate of patients with low nuclear PDCD4 expression was significantly lower than that of patients with high expression (72.2% vs. 93.3%, P<0.001). American Joint Committee on Cancer stage II and III colorectal cancer patients with low nuclear PDCD4 expression (76.9% and 67.2%, respectively) showed significantly worse overall survival than those with high expression (100% and 92.9%, P=0.002 and 0.032, respectively). Low nuclear PDCD4 expression was an independent poor prognostic factor in colorectal cancer patients (hazard ratio=3.556; 95% confidence interval, 1.739-7.271; P=0.001). Our study suggests that low PDCD4 expression is associated with aggressive behavior and can be used as a prognostic indicator of colorectal cancer patients.

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.

Influence of miRNA-30a-5p on Pulmonary Fibrosis in Mice with Streptococcus pneumoniae Infection through Regulation of Autophagy by Beclin-1

The study is aimed at observing the influence of microribonucleic acid- (miRNA-) 30a-50p on the pulmonary fibrosis in mice with Streptococcus pneumoniae infection through the regulation of autophagy by Beclin-1. Specific pathogen-free mice were instilled with Streptococcus pneumoniae through the trachea to establish the pulmonary fibrosis model. Then, they were divided into the miRNA-30a-50p mimics group (mimics group, n = 10) and miRNA-30a-5p inhibitors group (inhibitors group, n = 10), with the control group (n = 10) also set. Pulmonary tissue wet weight/dry weight (W/D) was detected. The content of tumor necrosis factor-α (TNF-α), interleukin- (IL-) 6, and myeloperoxidase (MPO) was determined using enzyme-linked immunosorbent assay (ELISA). Besides, the changes in the pulmonary function index dynamic lung compliance (Cdyn), plateau pressure (Pplat), and peak airway pressure (Ppeak) were monitored, and the gene and protein expression levels were measured via quantitative PCR (qPCR) and Western blotting. The expression level of miRNA-30a-5p was substantially raised in the mimics group (p < 0.05), but extremely low in the inhibitors group (p < 0.05). The mimics group had obviously raised levels of serum aminotransferase (AST), glutamic-pyruvic transaminase (GPT), alkaline phosphatase (ALP), and pulmonary tissue W/D (p < 0.05). Additionally, the expression levels of TNF-α, IL-6, and MPO were notably elevated in the mimics group, while their expression levels showed the opposite conditions in the inhibitors group (p < 0.05). According to the HE staining results, the inhibitors group had arranged orderly cells, while the mimics group exhibited lung injury, pulmonary edema, severe inflammatory response, and alveolar congestion. In the inhibitors group, Cdyn was remarkably elevated, but Pplat and Ppeak declined considerably (p < 0.05). Besides, the inhibitors group exhibited elevated messenger RNA (mRNA) levels of Beclin-1 and LC3, lowered mRNA levels of α-SMA and p62, a raised protein level of Beclin-1, and a markedly decreased protein level of p62 (p < 0.05). Silencing miRNA-30a-5p expression can promote the expression of Beclin-1 to accelerate the occurrence of autophagy, thereby treating pulmonary fibrosis in mice with Streptococcus pneumoniae infection.

Clinical Significance of PDCD4 in Melanoma by Subcellular Expression and in Tumor-Associated Immune Cells

Simple Summary

While targeting programmed cell death (PDCD) 1 is a central treatment against melanoma, little is known about the related protein PDCD4. We defined differences in melanoma PDCD4 subcellular localization (either total cellular or nuclear-only) during oncogenesis, evaluated its presence on tumor-infiltrating immune cells, and determined its impact on survival. High PDCD4 expression resulted in improved survival in patients with primary and intracranial but not extracranial metastatic melanoma. High PDCD4 levels in surrounding tumor tissue were also associated with increased infiltrating immune cells. PDCD4 may be a potentially useful biomarker in melanoma to help guide our understanding of patient prognosis. Methods to increase PDCD4 in those with melanoma brain metastases may also help improve disease response.

Abstract

Little is known about the subcellular localization and function of programmed cell death 4 (PDCD4) in melanoma. Our past studies suggest PDCD4 interacts with Pleckstrin Homology Domain Containing A5 (PLEKHA5) to influence melanoma brain metastasis outcomes, as high intracranial PDCD4 expression leads to improved survival. We aimed to define the subcellular distribution of PDCD4 in melanoma and in the tumor microenvironment during neoplastic progression and its impact on clinical outcomes. We analyzed multiple tissue microarrays with well-annotated clinicopathological variables using quantitative immunofluorescence and evaluated single-cell RNA-sequencing on a brain metastasis sample to characterize PDCD4+ immune cell subsets. We demonstrate differences in PDCD4 expression during neoplastic progression, with high tumor and stromal PDCD4 levels associated with improved survival in primary melanomas and in intracranial metastases, but not in extracranial metastatic disease. While the expression of PDCD4 is well-documented on CD8+ T cells and natural killer cells, we show that it is also found on B cells and mast cells. PDCD4 expression in the tumor microenvironment is associated with increased immune cell infiltration. Further studies are needed to define the interaction of PDCD4 and PLEKHA5 and to evaluate the utility of this pathway as a therapeutic target in melanoma brain metastasis.

The Roles of Matrix Metalloproteinases and Their Inhibitors in Human Diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

Synthetic circular miR-21 RNA decoys enhance tumor suppressor expression and impair tumor growth in mice

Naturally occurring circular RNAs efficiently impair miRNA functions. Synthetic circular RNAs may thus serve as potent agents for miRNA inhibition. Their therapeutic effect critically relies on (i) the identification of optimal miRNA targets, (ii) the optimization of decoy structures and (iii) the development of efficient formulations for their use as drugs. In this study, we extensively explored the functional relevance of miR-21-5p in cancer cells. Analyses of cancer transcriptomes reveal that miR-21-5p is the by far most abundant miRNA in human cancers. Deletion of the MIR21 locus in cancer-derived cells identifies several direct and indirect miR-21-5p targets, including major tumor suppressors with prognostic value across cancers. To impair miR-21-5p activities, we evaluate synthetic, circular RNA decoys containing four repetitive binding elements. In cancer cells, these decoys efficiently elevate tumor suppressor expression and impair tumor cell vitality. For their in vivo delivery, we for the first time evaluate the formulation of decoys in polyethylenimine (PEI)-based nanoparticles. We demonstrate that PEI/decoy nanoparticles lead to a significant inhibition of tumor growth in a lung adenocarcinoma xenograft mouse model via the upregulation of tumor suppressor expression. These findings introduce nanoparticle-delivered circular miRNA decoys as a powerful potential therapeutic strategy in cancer treatment.

Nuclear PDCD4 Expression Defines a Subset of Luminal B-Like Breast Cancers with Good Prognosis

The hormone receptor-positive (estrogen and/or progesterone receptor (PR)-positive) and HER2-negative breast cancer (BC) subtype is a biologically heterogeneous entity that includes luminal A-like (LumA-like) and luminal B-like (LumB-like) subtypes. Decreased PR levels is a distinctive biological feature of LumB-like tumors. These tumors also show reduced sensitivity to endocrine therapies and poorer prognosis than LumA-like tumors. Identification of biomarkers to accurately predict disease relapse in these subtypes is crucial in order to select effective therapies. We identified the tumor suppressor PDCD4 (programmed cell death 4), located in the nucleus (NPDCD4), as an independent prognostic factor of good clinical outcome in LumA-like and LumB-like subtypes. NPDCD4-positive LumB-like tumors presented overall and disease-free survival rates comparable to those of NPDCD4-positive LumA-like tumors, indicating that NPDCD4 improves the outcome of LumB-like patients. In contrast, NPDCD4 loss increased the risk of disease recurrence and death in LumB-like compared with LumA-like tumors. This, along with our results showing that LumB-like tumors present lower NPDCD4 positivity than LumA-like tumors, suggests that NPDCD4 loss contributes to endocrine therapy resistance in LumB-like BCs. We also revealed that PR induces PDCD4 transcription in LumB-like BC, providing a mechanistic explanation to the low PDCD4 levels in LumB-like BCs lacking PR. Finally, PDCD4 silencing enhanced BC cell survival in a patient-derived explant model of LumB-like disease. Our discoveries highlight NPDCD4 as a novel biomarker in LumA- and LumB-like subtypes, which could be included in the panel of immunohistochemical markers used in the clinic to accurately predict the prognosis of LumB-like tumors.

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.

MiR-629-5p promotes the invasion of lung adenocarcinoma via increasing both tumor cell invasion and endothelial cell permeability

Tumor invasion underlies further metastasis, the leading cause for cancer-related deaths. Deregulation of microRNAs has been identified associated with the malignant behavior of various cancers, including lung adenocarcinoma (LUAD), the major subtype of lung cancer. Here, we showed the significantly positive correlation between miR-629-5p level and tumor invasion in LUAD specimens (n = 49). In a human LUAD metastasis mouse model, H1650 cells (high level of miR-629-5p) were more aggressive than A549 cells (low level of miR-629-5p) in vivo, including higher incidence of vascular invasion and pulmonary colonization. Ectopic expression of miR-629-5p in A549 cells also increased their invasive capability. Then we identified that miR-629-5p promotes LUAD invasion in a mode of dual regulation via tumor cells invasion and endothelial cells permeability, respectively. In tumor cells, miR-629-5p enhanced motility and invasiveness of tumor cells by directly targeting PPWD1 (a cyclophilin), which clinically related to tumor invasion in LUAD specimens. Restoring PPWD1 protein significantly attenuated the invasion-promoting effects of miR-629-5p. Besides, exosomal-miR-629-5p secreted from tumor cells could be transferred to endothelial cells and increased endothelial monolayers permeability by suppressing CELSR1 (a nonclassic-type cadherin), which had a low level in the endothelial cells of invasive LUAD specimens. Activating the expression of CELSR1 in endothelial cells markedly blocked the effect of miR-629-5p. Our study suggests the dual roles of miR-629-5p in tumor cells and endothelial cells for LUAD invasion, implying a therapeutic option to targeting miR-629-5p using the "one stone, two birds" strategy in LUAD.

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.

PLEKHA5 regulates tumor growth in metastatic melanoma

BACKGROUND

PLEKHA5 has previously been identified as a novel molecule implicated in melanoma brain metastasis, a disease that continues to portend a poor prognosis. The aim of this study was to further investigate the functional role of PLEKHA5 in disseminated melanoma.

METHODS

The impact of PLEKHA5 on proliferation and tumor growth was examined in vitro and in melanoma xenograft models, including brain-tropic melanomas (melanomas tending to disseminate to the brain). In vitro loss- and gain-of-function studies were used to explore the underlying mechanisms of PLEKHA5-mediated tumor growth and the crosstalk between PLEKHA5 and PI3K/AKT/mTOR or MAPK/ERK signaling. The clinical relevance of PLEKHA5 dysregulation was further investigated in a cohort of matched cranial and extracranial melanoma metastases.

RESULTS

PLEKHA5 stable knockdown negatively regulated cell proliferation by inhibiting the G₁ -to-S cell cycle transition, which coincided with upregulation of the cell cycle regulator PDCD4. Conversely, ectopic PLEKHA5 expression exhibited the inverse effect. PLEKHA5 knockdown significantly inhibited tumor growth, whereas its overexpression upregulated the growth of tumors, which was induced by cranial and subcutaneous inoculation of cells in nude mice. PLEKHA5 modulation affected PDCD4 protein stability and was coupled with changes in PI3K/AKT/mTOR pathway signaling. High PDCD4 expression in cerebral specimens was associated with better overall survival.

CONCLUSIONS

This study further supports the role of PLEKHA5 as a regulator of melanoma growth at distant sites, including the brain. Furthermore, the results highlight the significance of PDCD4 dysregulation in disseminated melanoma and implicate PDCD4 as a possible causal link between PLEKHA5 and cell proliferation and growth.

miRNA and Gene Expression in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging disease that is mostly diagnosed late in the course of the illness. Unlike other cancers in which measurable successes have been achieved with traditional chemotherapy, targeted therapy, and, recently, immunotherapy, PDAC has proved to be poorly responsive to these treatments, with only marginal to modest incremental benefits using conventional cytotoxic therapy. There is, therefore, a great unmet need to develop better therapies based on improved understanding of biology and identification of predictive and prognostic biomarkers that would guide therapy. miRNAs are small noncoding RNAs that regulate the expression of some key genes by targeting their 3'-untranslated mRNA region. Aberrant expression of miRNAs has been linked to the development of various malignancies, including PDAC. A series of miRNAs have been identified as potential tools for early diagnosis, prediction of treatment response, and prognosis of patients with PDAC. In this review, we present a summary of the miRNAs that have been studied in PDAC in the context of disease biology.

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

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

Novel Biomarkers for Personalized Cancer Immunotherapy

Cancer immunotherapy has emerged as a novel and effective treatment strategy for several types of cancer. Immune checkpoint inhibitors (ICIs) have recently demonstrated impressive clinical benefit in some advanced cancers. Nonetheless, in the majority of patients, the successful use of ICIs is limited by a low response rate, high treatment cost, and treatment-related toxicity. Therefore, it is necessary to identify predictive and prognostic biomarkers to select the patients who are most likely to benefit from, and respond well to, these therapies. In this review, we summarize the evidence for candidate biomarkers of response to cancer immunotherapy.

TIMP-3 as a therapeutic target for cancer

Tissue inhibitor of metalloproteinase-3 (TIMP-3), a secreted glycoprotein, plays an important role in carcinogenesis. It can bind to many proteinases to suppress their activity and thus protect the extracellular matrix from degradation. TIMP-3 may have many anticancer properties, including apoptosis induction and antiproliferative, antiangiogenic, and antimetastatic activities. This review summarizes the structure, proteinase inhibition ability, genetic and epigenetic regulation, cancer therapy potential, and contribution to cancer development of TIMP-3. Furthermore, in this review we discuss its potential as a biomarker for predicting cancer progression and the current state of drugs that target TIMP-3, either alone or in combination with clinical treatment. In conclusion, TIMP-3 can be a biomarker of cancer and a potential target for cancer therapy. This review article can serve as a basis to understand how to modulate TIMP-3 levels as a drug target of cancers.

MicroRNA-21 and its impact on signaling pathways in cervical cancer

Oncogenic microRNA-21 (miR-21/miRNA-21) is a stable inhibitor of gene expression that is often upregulated in cervical cancer, a disease that affects the health of women and tends to transform and spread. Previous studies investigating miR-21 in biopsies and cells from cervical cancer patients have identified that miR-21 binds target mRNAs in signaling pathways or long non-coding RNAs (lncRNA). Furthermore, studies have elucidated the molecular mechanisms of two tumor necrosis factor α (TNF-α) signaling pathways that promote cell proliferation and inhibit cell apoptosis. miR-21 inhibits the TNF receptor 1 (TNFR1) signaling pathway and activates the TNFR2 signaling pathway. Moreover, miR-21 enhances cervical cancer cell proliferation by influencing the protein kinase B/mammalian target of rapamycin and RAS p21 protein activator 1 signaling pathways. The present review discusses the evidence that miR-21 may impact cervical cancer through inhibiting apoptosis and enhancing proliferation, and may therefore be a target for clinical intervention.

AngiomiRs: MicroRNAs driving angiogenesis in cancer (Review)

Angiogenesis is an important hallmark of cancer serving a key role in tumor growth and metastasis. Therefore, tumor angiogenesis has become an attractive target for development of novel drug therapies. An increased amount of anti‑angiogenic compounds is currently in preclinical and clinical development for personalized therapies. However, resistance to current angiogenesis inhibitors is emerging, indicating that there is a need to identify novel anti‑angiogenic agents. In the last decade, the field of microRNA biology has exploded revealing unsuspected functions in tumor angiogenesis. These small non‑coding RNAs, which have been dubbed as angiomiRs, may target regulatory molecules driving angiogenesis, such as cytokines, metalloproteinases and growth factors, including vascular endothelial growth factor, platelet‑derived growth factor, fibroblast growth factor, epidermal growth factor, hypoxia inducible factor‑1, as well as mitogen‑activated protein kinase, phosphoinositide 3‑kinase and transforming growth factor signaling pathways. The present review discusses the current progress towards understanding the functions of miRNAs in tumor angiogenesis regulation in diverse types of human cancer. Furthermore, the potential clinical application of angiomiRs towards anti‑angiogenic tumor therapy was explored.

Genetic variant in miR-21 binding sites is associated with colorectal cancer risk

Single nucleotide polymorphisms (SNPs) within binding sites of microRNAs (miRNAs) could modify cancer susceptibility by changing the binding affinity of miRNAs on their target mRNA 3'-untranslated regions (UTRs). MicroRNA-21 (miR-21) is involved in the development of colorectal cancer. However, the relationship between SNPs within the binding sites of miR-21 and colorectal cancer risk has not been widely investigated. A case-control study including 1147 patients and 1203 controls was performed to evaluate the association of SNPs in miR-21 binding sites and colorectal cancer risk. Dual-luciferase reporter assays and functional assays were performed to evaluate the effects of miR-21. The SNP rs6504593 C allele conferred an increased risk of colorectal cancer compared with the T allele in an additive model (odds ratio [OR] = 1.19, 95% confidence interval [CI] = 1.04-1.36, P = 0.011). Dual-luciferase reporter assays demonstrated that the rs6504593 T allele negatively post-transcriptionally regulated IGF2BP1 by altering the binding affinity of miR-21. Additionally, colorectal cancer cells transiently transfected with miR-21 mimics promoted cell proliferation and suppressed apoptosis, whereas inhibition of miR-21 decreased cell growth. These data suggest that the miR-21 binding site SNP rs6504593 in the IGF2BP1 3'-UTR may alter IGF2BP1 expression and contribute to colorectal cancer risk.

miR-222-3p promotes osteosarcoma cell migration and invasion through targeting TIMP3

BACKGROUND

Abnormal expression of miRNAs has been reported in osteosarcoma (OS), and miR-222-3p levels have been found to be increased in the serum of OS patients. However, the exact role of miR-222-3p in OS remains unclear. In the present study, we aimed to identify the molecular mechanism underlying the role of miR-222-3p in the development of OS.

METHODS

We examined the expression level of miR-222-3p in OS tissues and OS cells using reverse-transcription quantitative PCR (RT-qPCR) analysis. MTT, colony formation, and transwell invasion assays were used to analyze the effects of miR-222-3p on the proliferation and invasion ability of OS cells. Luciferase reporter gene assays were used to confirm the target gene of miR-222-3p in OS cells. Tumor xenografts were then used to investigate the role of miR-222-3p in OS growth in vivo.

RESULTS

The data of the present study demonstrated that miR-222-3p levels were increased in OS tissues and OS cells. Downregulation of miR-222-3p significantly inhibited the proliferation, migration, and invasion of OS cells in vitro. Further analysis revealed that tissue inhibitors of metalloproteinases 3 (TIMP3) is one of the functional target genes of miR-222-3p, and inhibition of TIMP3 efficiently rescues the blocking of cell proliferation and invasion mediated by miR-222-3p inhibitor in OS cells.

CONCLUSION

Our findings constitute evidence that miR-222-3p promotes OS cell proliferation and invasion through targeting TIMP3 mRNA and provide novel insight into the mechanism underlying the development of OS.

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.

Necuparanib, A Multitargeting Heparan Sulfate Mimetic, Targets Tumor and Stromal Compartments in Pancreatic Cancer

Pancreatic cancer has an abysmal 5-year survival rate of 8%, making it a deadly disease with a need for novel therapies. Here we describe a multitargeting heparin-based mimetic, necuparanib, and its antitumor activity in both in vitro and in vivo models of pancreatic cancer. Necuparanib reduced tumor cell proliferation and invasion in a three-dimensional (3D) culture model; in vivo, it extended survival and reduced metastasis. Furthermore, proteomic analysis demonstrated that necuparanib altered the expression levels of multiple proteins involved in cancer-driving pathways including organ development, angiogenesis, proliferation, genomic stability, cellular energetics, and invasion and metastasis. One protein family known to be involved in invasion and metastasis and altered by necuparanib treatment was the matrix metalloprotease (MMP) family. Necuparanib reduced metalloproteinase 1 (MMP1) and increased tissue inhibitor of metalloproteinase 3 (TIMP3) protein levels and was found to increase RNA expression of TIMP3. MMP enzymatic activity was also found to be reduced in the 3D model. Finally, we confirmed necuparanib's in vivo activity by analyzing plasma samples of patients enrolled in a phase I/II study in patients with metastatic pancreatic cancer; treatment with necuparanib plus standard of care significantly increased TIMP3 plasma protein levels. Together, these results demonstrate necuparanib acts as a broad multitargeting therapeutic with in vitro and in vivo anti-invasive and antimetastatic activity.

Combined inhibition of the PI3K/mTOR/MEK pathway induces Bim/Mcl-1-regulated apoptosis in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) progression and chemotherapy insensitivity have been associated with aberrant PI3K/mTOR/MEK signalling. However, cell death responses activated by inhibitors of these pathways can differ – contextually varying with tumour genetic background. Here, we demonstrate that combining the dual PI3K/mTOR inhibitor PF5212384 (PF384) and MEK inhibitor PD325901 (PD901) more effectively induces apoptosis compared with either agent alone, independent of KRAS mutational status in PDAC cell lines. Additionally, a non-caspase dependent decrease in cell viability upon PF384 treatment was observed, and may be attributed to autophagy and G0/G1 cell cycle arrest. Using reverse phase protein arrays, we identify key molecular events associated with the conversion of cytostatic responses (elicited by single inhibitor treatments) into a complete cell death response when PF384 and PD901 are combined. This response was also independent of KRAS mutation, occurring in both BxPC3 (KRAS wildtype) and MIA-PaCa-2 (KRAS^G12C mutated) cells. In both cell lines, Bim expression increased in response to PF384/PD901 treatment (by 60% and 48%, respectively), while siRNA-mediated silencing of Bim attenuated the apoptosis induced by combination treatment. In parallel, Mcl-1 levels decreased by 36% in BxPC3, and 30% in MIA-PaCa-2 cells. This is consistent with a functional role for Mcl-1, and siRNA-mediated silencing enhanced apoptosis in PF384/PD901-treated MIA-PaCa-2 cells, whilst Mcl-1 overexpression decreased apoptosis induction by 24%. Moreover, a novel role was identified for PDCD4 loss in driving the apoptotic response to PF384/PD901 in BxPC3 and MIA-PaCa-2 cell lines. Overall, our data indicates PF384/PD901 co-treatment activates the same apoptotic mechanism in wild-type or KRAS mutant PDAC cells.

Role of microRNA-21 in uveal melanoma cell invasion and metastasis by regulating p53 and its downstream protein

AIM

To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets.

METHODS

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 (LASP1) and glutathione S transferase pi (GST-Pi) were determined by qRT-PCR in mRNA level and Western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice.

RESULTS

Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.

CONCLUSION

These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Inhibition of miR-21 ameliorates excessive astrocyte activation and promotes axon regeneration following optic nerve crush

Optic nerve injury is a leading cause of irreversible visual impairment worldwide and can even cause blindness. Excessive activation of astrocytes has negative effects on the repair and recovery of retinal ganglion cells following optic nerve injury. However, the molecular and cellular mechanisms underlying astrocyte activation after optic nerve injury remain largely unknown. In the present study, we explored the effects of microRNA-21 (miR-21) on axon regeneration and flash visual evoked potential (F-VEP) and the underlying mechanisms of these effects based on astrocyte activation in the rat model of optic nerve crush (ONC). To the best of our knowledge, this article is the first to report that inhibition of miR-21 enhances axonal regeneration and promotes functional recovery in F-VEP in the rat model of ONC. Furthermore, inhibition of miR-21 attenuates excessive astrocyte activation and glial scar formation, thereby promoting axonal regeneration by regulating the epidermal growth factor receptor (EGFR) pathway. In addition, we observed that the expression of tissue inhibitor of metalloproteinase-3, a target gene of miR-21, was inhibited during this process. Taken together, these findings demonstrate that inhibition of miR-21 regulates the EGFR pathway, ameliorating excessive astrocyte activation and glial scar progression and promoting axonal regeneration and alleviating impairment in F-VEP function in a model of ONC. This study's results suggest that miR-21 may represent a therapeutic target for optic nerve injury.

Immunoexpression of programmed cell death 4 protein in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma

Background:

Oral squamous cell carcinoma (OSCC) is the frequently reported cancer of the head and neck. Recent studies are being conducted to evaluate the role of potential markers for diagnosing the stages of development of OSCC from normal cells.

Aim:

The aim of this study is to evaluate and compare the immunoexpression of programmed cell death 4 (PDCD4) protein in normal oral mucosa, oral epithelial dysplasia (OED) and OSCC.

Materials and Methods:

Histologically diagnosed, formalin-fixed paraffin-embedded archived cases (n = 100) of normal mucosa (n = 10), OED (n = 60) and OSCC (n = 30) were analyzed immunohistochemically in the present retrospective study using monoclonal rabbit antihuman PDCD4. OED and squamous cell carcinoma were graded according to the World Health Organization and Broder's histological grading criteria, respectively. Clinical parameters and immunohistochemical results were analyzed by Fisher exact test using SPSS software. P <0.05 was indicative of significant differences.

Results:

PDCD4 expression was observed in the normal oral mucosa, OED and OSCC. The maximum expression was observed in the normal oral mucosa, which reduced significantly in OED and OSCC (P = 0.017). With the increase in the transformation from normal cells to cancer cells, a shift from nuclear to cytoplasmic staining was observed indicating predominant cytoplasmic localization of stain as a feature of altered cells.

Conclusion:

The present study delineates the molecular difference between the normal, dysplastic and carcinomatous cells; and points toward the role of PDCD4 localization in the proliferation of cells. This study thus highlights the need for further research with inclusion of long follow-up period and other pathological criteria such as inflammation and microenvironment, immune status of patient and tumor stage, which could aid in the development of prospective diagnostic options.

An elevated expression of serum exosomal microRNA-191, - 21, -451a of pancreatic neoplasm is considered to be efficient diagnostic marker

BACKGROUND

Pancreatic cancer is associated with an extremely poor prognosis, so new biomarkers that can detect the initial stages are urgently needed. The significance of serum microRNA (miR) levels in pancreatic neoplasm such as pancreatic cancer and intraductal papillary mucinous neoplasm (IPMN) diagnosis remains unclear. We herein evaluated the usefulness of miRs enclosed in serum exosomes (ExmiRs) as diagnostic markers.

METHODS

The ExmiRs from patients with pancreatic cancer (n = 32) or IPMN (n = 29), and patients without neoplasms (controls; n = 22) were enriched using ExoQuick-TC™. The expression of ExmiRs was evaluated using a next-generation sequencing analysis, and the selected three miRs through this analysis were confirmed by a quantitative real-time polymerase chain reaction.

RESULTS

The expression of ExmiR-191, ExmiR-21 and ExmiR-451a was significantly up-regulated in patients with pancreatic cancer and IPMN compared to the controls (p < 0.05). A receiver operating characteristic curve analysis showed that the area under the curve and the diagnostic accuracy of ExmiRs were 5-20% superior to those of three serum bulky circulating miRs (e.g.; ExmiR-21: AUC 0.826, accuracy 80.8%. Circulating miR-21: AUC 0.653, accuracy 62.3%). In addition, high ExmiR-451a was associated with mural nodules in IPMN (p = 0.010), and high ExmiR-21 was identified as a candidate prognostic factor for the overall survival (p = 0.011, HR 4.071, median OS of high-ExmiR-21: 344 days, median OS of low-ExmiR-21: 846 days) and chemo-resistant markers (p = 0.022).

CONCLUSIONS

The level of three ExmiRs can thus serve as early diagnostic and progression markers of pancreatic cancer and IPMN, and considered more useful markers than the circulating miRs (limited to these three miRs).

Deciphering microRNA targets in pancreatic cancer using miRComb R package

MiRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression. They play important roles in cancer but little is known about the specific functions that each miRNA exerts in each type of cancer. More knowledge about their specific targets is needed to better understand the complexity of molecular networks taking part in cancer. In this study we report the miRNA-mRNA interactome occurring in pancreatic cancer by using a bioinformatic approach called miRComb, which combines tissue expression data with miRNA-target prediction databases (TargetScan, miRSVR and miRDB). MiRNome and transcriptome of 12 human pancreatic tissues (9 pancreatic ductal adenocarcinomas and 3 controls) were analyzed by next-generation sequencing and microarray, respectively. Analysis confirmed differential expression of both miRNAs and mRNAs in cancerous tissue versus control, and unveiled 17401 relevant miRNA-mRNA interactions likely to occur in pancreatic cancer. They were sorted according to the degree of negative correlation between miRNA and mRNA expression. Results highlighted the importance of miR-148a and miR-21 interactions among others. Two components of the Notch signaling pathway, ADAM17 and EP300, were confirmed as miR-148a targets in MiaPaca-2 pancreatic cancer cells overexpressing miR-148a. Moreover, a CRISPR-Cas9 cellular model was generated to knock-out the expression of miR-21 in PANC-1 cells. As expected, the expression of two miRComb miR-21 predicted targets, PDCD4 and BTG2, was significantly upregulated in these cells in comparison to control PANC-1.

MicroRNA-196a-5p is a potential prognostic marker of delayed lymph node metastasis in early-stage tongue squamous cell carcinoma

MicroRNAs (miRs) are expected to serve as prognostic tools for cancer. However, many miRs have been reported as prognostic markers of recurrence or metastasis in oral squamous cell carcinoma patients. We aimed to determine the prognostic markers in early-stage tongue squamous cell carcinoma (TSCC). Based on previous studies, we hypothesized that miR-10a, 10b, 196a-5p, 196a-3p, and 196b were prognostic markers and we retrospectively performed miR expression analyses using formalin-fixed paraffin-embedded sections of surgical specimens. Total RNA was isolated from cancer tissues and adjacent normal tissue as control, and samples were collected by laser-capture microdissection. After cDNA synthesis, reverse transcription-quantitative polymerase chain reaction was performed. Statistical analyses for patient clinicopathological characteristics, recurrence/metastasis, and survival rates were performed to discern their relationships with miR expression levels, and the 2^−ΔΔCq method was used. miR-196a-5p levels were significantly upregulated in early-stage TSCC, particularly in the lymph node metastasis (LNM) group. The LNM-free survival rate in the low miR-196a-5p ΔΔCq value regulation group was found to be lower than that in the high ΔΔCq value regulation group (P=0.0079). Receiver operating characteristic analysis of ΔΔCq values revealed that miR-196a-5p had a P-value=0.0025, area under the curve=0.740, and a cut-off value=−0.875 for distinguishing LNM. To our knowledge, this is the first study to examine LNM-related miRs in early-stage TSCC as well as miRs and ‘delayed LNM’ in head and neck cancer. miR-196a-5p upregulation may predict delayed LNM. Our data serve as a foundation for future studies to evaluate miR levels and facilitate the prediction of delayed LNM during early-stage TSCC, which prevent metastasis when combined with close follow-up and aggressive adjuvant therapy or elective neck dissection. Moreover, our data will serve as a foundation for future studies to evaluate whether miR-196a-5p can serve as a therapeutic marker for preventing metastasis.

Serum metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in lung carcinoma patients

Background

Assessment of serum extracellular matrix (ECM) metalloproteinase MMP-2 and tissue inhibitor of matrix metalloproteinase TIMP-2 concentrations in non-small cell lung carcinoma (NSCLC) patients considering TNM staging. Assessment of the prognostic value of MMP-2 and TIMP-2 concentrations in NSCLC patients.

Methods

The study group consisted of 81 NSCLC patients (24 females and 57 males) aged 46 to 86 years (mean age of 67±8.2 years). The control group comprised 39 randomly selected patients (20 females and 19 males) aged 27 to 73 years (mean age of 47±15.0 years) in whom primary lung cancer was excluded and who were operated on for a calculus of the gallbladder without cholecystitis. Blood serum MMP-2 and TIMP-2 concentrations were determined using an enzyme-linked immunosorbent assay (ELISA)-based test.

Results

Statistically significantly higher mean MMP-2 and TIMP-2 concentrations were found in NSCLC patients compared to those in the control group (P<0.001). Statistically significant differences in MMP-2 and TIMP-2 concentrations between patients with T1 and T2 tumour and patients with T3 and T4 tumour, as well as between the group without metastases (N0) and the group with metastases to lymph nodes were demonstrated. Moreover, a significant fall in mean MMP-2 and TIMP-2 concentrations was observed in the postoperative compared to preoperative period (P<0.001).

Conclusions

Serum MMP-2 and TIMP-2 concentrations in NSCLC patients correlated with the tumour size and presence of metastases to lymph nodes and thus may serve as an auxiliary parameter indicating probability of a more advanced stage of lung cancer.

Prognostic value of microRNA expression levels in pancreatic adenocarcinoma: a review of the literature

Background

Clinical and pathologic markers of prognosis and patterns of failure help guide clinicians in selecting patients for adjuvant therapy after surgical resection for pancreatic adenocarcinoma (PDAC). Recent studies have reported the prognostic utility of microRNA profiling in numerous malignancies. Here, we review and summarize the current literature regarding associations between microRNA expression and overall survival in PDAC patients.

Materials and Methods

We conducted a systematic search in the PubMed database to identify all primary research studies reporting prognostic associations between tumor and/or serum microRNA expression and overall survival in PDAC patients. Eligible articles were reviewed by the authors and relevant findings are summarized below.

Results

We found 53 publications that fit our search criteria. In total, 23 up-regulated and 49 down-regulated miRNAs have been associated with worse overall survival. MiR-21 is the most commonly reported miRNA, appearing in 19 publications, all of which report aberrant over-expression and association with shorter survival in PDAC. Other miRNAs that appear in multiple publications include miR-10b, −21, −34a, −155, −196a, −198, −200c, −203, −210, −218, −222, and −328. We summarize the preclinical and clinical data implicating these miRNAs in various molecular signaling pathways and cellular functions.

Conclusions

There is growing evidence that miRNA expression profiles have the potential to provide tumor-specific prognostic information to assist clinicians in more appropriately selecting patients for adjuvant therapy. These molecules are often aberrantly expressed and exhibit oncogenic and/or tumor suppressor functions in PDAC. Additional efforts to develop prognostic and predictive molecular signatures, and further elucidate miRNA mechanisms of action, are warranted.

MicroRNA-21 Inhibits the Apoptosis of Osteosarcoma Cell Line SAOS-2 via Targeting Caspase 8

Currently, multiple microRNAs (miRNAs) have been found to play vital roles in the pathogenesis of osteosarcoma. This study aimed to investigate the role of miR-21 in osteosarcoma. The level of miR-21 in 20 pairs of osteosarcoma and corresponding adjacent tissues was monitored by qPCR. Human osteosarcoma cell line SAOS-2 was transfected with either miR-21 mimic or miR-21 inhibitor, and then cell viability, survival, and apoptosis were measured by MTT, colony formation assay, and flow cytometry. A target of miR-21 was predicted by the microRNA.org database and verified in vitro by using luciferase reporter, qPCR, and Western blot analyses. Finally, cells were cotransfected with siRNA against caspase 8 and miR-21 inhibitor, and the apoptotic cell rate was determined again. Results showed that the mRNA level of miR-21 was highly expressed in osteosarcoma tissues compared with adjacent tissues. Overexpression of miR-21 improved cell viability and survival but suppressed apoptosis. Caspase 8 was a direct target of miR-21, and it was negatively regulated by miR-21. Moreover, miR-21 suppression attenuated caspase 8 silencing and induced the decrease in apoptosis. In conclusion, overexpression of miR-21 suppressed SAOS-2 cell apoptosis via directly targeting caspase 8.

miR-144 may regulate the proliferation, migration and invasion of trophoblastic cells through targeting PTEN in preeclampsia

Previous studies indicated that microRNAs (miRNAs) were aberrantly expressed in the placentas of patients with Preeclampsia (PE); however, the underlying mechanism still requires further investigation. The aim of this study is to investigate the roles of miR-144 in preeclampsia and the related mechanism. The expression of miR-144 and PTEN in 30 placentas of patients with PE and 30 normal placentas was compared; next, HTR8/SVneo cells were transfected with miR-144 mimics and miR-144 inhibitors and cultured for 48h, and the proliferation and apoptosis, cell migration and invasion of the cells were examined; furthermore, the expression PTEN, Caspase-3 and Bcl-2 was examined; next, dual luciferase reporter assay has been performed to confirm that PTEN is a direct target of miR-144; finally, HTR-8/SVneo cells were transfected with either PTEN overexpression plasmid or PTEN RNAi to determine whether knockdown or overexpression of PTEN can mimic the effect of miR-144 We have observed that the expression of miR-144 was significantly decreased and the expression of PTEN was markedly increased in placentas of patients with PE compared with normal placentas; moreover, transfection of miR-144 mimics in trophoblastic cells induced significant increase in cell proliferation, migration, invasion, and decrease in cell apoptosis, and also affected the cell cycles; on the other hand, transfection of miR-144 inhibitors has shown the opposite effects; furthermore, transient overexpression of miR-144 induced marked decrease in the expression of PTEN, Caspase-3 and increase in expression of Bcl-2 (P<0.01), while transfection of miR-144 inhibitors showed the opposite effects; finally, PTEN has been confirmed as a direct target of miR-144; finally, transfection of PTEN overexpression plasmid or PTEN RNAi can mimic the results of miR-144 inhibitor or miR-144 mimics, respectively. In conclusion, miR-144 was down-regulated in PE, and miR-144 may play important roles in the pathogenesis of PE through targeting PTEN in trophoblastic cells. These results suggested that miR-144 has the potential to become a therapeutic target for the treatment of PE.

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.