Inhibiting Anti-angiogenic VEGF165b Activates a Novel miR-17-20a-Calcipressin-3 Pathway that Revascularizes Ischemic Muscle in Peripheral Artery Disease

Background

VEGF165a increases the expression of microRNA-17-92 cluster, promoting developmental, retinal, and tumor angiogenesis. We have previously shown that VEGF165b, an alternatively spliced VEGF-A isoform, inhibits the VEGFR-STAT3 pathway in ischemic endothelial cells (ECs) to decrease their angiogenic capacity. In ischemic macrophages (Møs), VEGF165b inhibits VEGFR1 to induce S100A8/A9 expression, which drives M1-like polarization. Our current study aims to determine whether VEGF165b inhibition promotes perfusion recovery by regulating the miR-17-92 cluster in preclinical PAD.

Methods

Hind limb ischemia (HLI) induced by femoral artery ligation and resection was used as a preclinical PAD model. Hypoxia serum starvation (HSS) was used as an in vitro PAD model. VEGF165b was inhibited/neutralized by an isoform-specific VEGF165b antibody.

Results

Systematic analysis of miR-17-92 cluster members (miR-17-18a-19a-19b-20a-92) in experimental-PAD models showed that VEGF165b-inhibition induces miRNA-17-20a (within miR-17-92 cluster) in HSS-ECs and HSS-bone marrow derived macrophages (BMDMs) vs. respective normal and/or isotype matched IgG controls to enhance perfusion-recovery. Consistent with the bioinformatics analysis that revealed RCAN3 as a common target of miR-17 and miR-20a, Argonaute-2 pull-down assays showed decreased miR-17-20a expression and higher RCAN3 expression in the RISC complex of HSS-ECs and HSS-BMDMs vs. the respective controls. Inhibiting miR-17-20a induced RCAN3 levels to decrease ischemic angiogenesis and promoted M1-like polarization to impair perfusion recovery. Finally, using STAT3 inhibitors, S100A8/A9 silencers and VEGFR1-deficient ECs and Møs, we show that VEGF165b inhibition activates the miR-17-20a-RCAN3 pathway independent of VEGFR1-STAT3 or VEGFR1-S100A8/A9 in ischemic ECs and ischemic Møs, respectively.

Conclusion

Our data revealed a hereunto unrecognized therapeutic 'miR-17-20a-RCAN3' pathway in the ischemic vasculature that is VEGFR1-STAT3/S100A8/A9 independent and is activated only upon VEGF165b inhibition in PAD.

Evaluating the presence of deregulated tumoral onco-microRNAs in serum-derived exosomes of gastric cancer patients as noninvasive diagnostic biomarkers

Introduction: Exosomal microRNAs (miRNAs) are emerging diagnostic biomarkers for different types of cancers. We aim to detect gastric cancer (GC)-specific miRNAs in serum exosomes with diagnostic potential.

Methods: A pair of 43 tumor and tumor-adjacent tissue biopsies obtained from GC patients, also 5 mL peripheral blood (following 12h fasting) were collected from the same patients and healthy controls (HCs). QIAGEN miRCURY LNA miRNA Focus PCR Panel applied to screen differentially expressed onco-miRNAs. The candidate miRNAs with the highest fold changes proceeded for validation by qRT-PCR in individuals.

Results: We identified that exosomal miR-10a-5p, miR-19b-3p, miR-215-5p, and miR-18a-5p were significantly upregulated in GC patient’s exosomes in contrast to HCs exosomes, Roc curve analysis indicated area under the ROC curve (AUC) of 0.801, 0.721, 0.780 and 0.736 respectively. The Roc curve analysis for the combined signature of four exosomal miRNAs indicated AUC of 0.813. Also, Spearman's correlation coefficients indicated that the miRNA expression is highly correlated between tumor and exosome.

Conclusion: Herein, we specifically identified four miRNAs in serum exosomes of GC patients for a diagnostic purpose which are directly associated with tumoral miRNA expression profile.

Cervical cancer development, chemoresistance, and therapy: a snapshot of involvement of microRNA

Cervical cancer (CC) is one of the leading causes of death in women due to cancer and a major concern in the developing world. Persistent human papilloma virus (HPV) infection is the major causative agent for CC. Besides HPV infection, genetic and epigenetic factors including microRNA (miRNA) also contribute to the malignant transformation. Earlier studies have revealed that miRNAs participate in cell proliferation, invasion and metastasis, angiogenesis, and chemoresistance processes by binding and inversely regulating the target oncogenes or tumor suppressor genes. Based on functions and mechanistic insights, miRNAs have been identified as cellular modulators that have an enormous role in diagnosis, prognosis, and cancer therapy. Signatures of miRNA could be used as diagnostic markers which are necessary for early diagnosis and management of CC. The therapeutic potential of miRNAs has been shown in CC; however, more comprehensive clinical trials are required for the clinical translation of miRNA-based diagnostics and therapeutics. Understanding the molecular mechanism of miRNAs and their target genes has been useful to develop miRNA-based therapeutic strategies for CC and overcome chemoresistance. In this review, we summarize the role of miRNAs in the development, progression, and metastasis of CC as well as chemoresistance. Further, we discuss the diagnostic and therapeutic potential of miRNAs to overcome chemoresistance and treatment of CC.

Molecular Mechanisms of PD-1 and PD-L1 Activity on a Pan-Cancer Basis: A Bioinformatic Exploratory Study

Immune checkpoint blockade targeting PD-1 (PDCD1)/PD-L1 (CD274) is increasingly used for multiple cancers. However, efficacy and adverse-related events vary significantly. This bioinformatic study interrogated molecular differences pertaining to PDCD1/CD274 and their correlated genes on a pan-cancer basis to identify differences between cancer types. Patient RNA-seq data from fifteen cancer types were accessed on cBioPortal to determine the role of PDCD1/CD274 in patient survival and to identify positively and negatively correlated genes, which were also assessed for clinical relevance. Genes correlating with PDCD1/CD274 across multiple cancers were taken forward for drug repurposing via DRUGSURV and microRNA analysis using miRDB and miRabel. MicroRNAs were also screened for clinical relevance using OncomiR. Forty genes were consistently correlated with PDCD1/CD274 across multiple cancers, with the cancers themselves exhibiting a differential role for the correlated genes in terms of patient survival. Esophageal and renal cancers in particular stood out in this regard as having a unique survival profile. Forty-nine putative microRNAs were identified as being linked to the PDCD1/CD274 network, which were taken forward and further assessed for clinical relevance using OncomiR and previously published literature. One hundred and thirty significant survival associations for 46 microRNAs across fourteen groups of cancers were identified. Finally, a total of 23 putative repurposed drugs targeting multiple components of the PDCD1/CD274 network were identified, which may represent immunotherapeutic adjuvants. Taken together, these results shed light on the varying PDCD1/CD274 networks between individual cancers and signpost a need for more cancer-specific investigations and treatments.

MicroRNAs Involved in Inflammatory Breast Cancer: Oncogene and Tumor Suppressors with Possible Targets

Inflammatory breast cancer (IBC) as a rare and highly aggressive type of breast cancer displays phenotypic characteristics. To date, the IBC-associated molecular mechanisms are entirely unknown. In addition, there is an urgent need to identify the new biomarkers involved in the diagnosis and therapeutic purposes of IBC. MicroRNAs, a category of short noncoding RNAs, are capable of controlling the post-transcriptional expression of genes and thus can act as diagnostic predictive tools. In this review, we addressed the status of oncogenic and tumor suppressor miRNA-mediated IBC in current studies. Furthermore, based on their targets, their involvement in cancer progression, angiogenesis, metastasis, and apoptosis were determined.

MicroRNA-99 family in cancer and immunity

The microRNA (miR)-99 family comprising miR-99a, miR-99b, and miR-100 is an evolutionarily conserved family with existence dating prior to the bilaterians. Members are typically oncogenic in leukemia while their functional roles in other cancers alternate between that of a tumor suppressor and a tumor promoter. Targets of the miR-99 family rank in the lists of oncogenes and tumor suppressors, thereby illustrating the dual role of this miR family as oncogenic miRs (oncomiRs) and tumor suppressing miRs (TSmiRs) in different cellular contexts. In addition to their functional roles in cancers, miR-99 family is implicated in the modulation of macrophage inflammatory responses and T-cell subsets biology, thereby exerting critical roles in the maintenance of tissue homeostasis, establishment of peripheral tolerance as well as resolution of an inflammatory reaction. Here, we review emerging knowledge of this miR family and discuss remaining concerns linked to their activities. A better dissection of the functional roles of miR-99 family members in cancer and immunity will help in the development of novel miR-99-based therapeutics for the treatment of human cancer and immune-related diseases. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Differential expression of miR-1297, miR-3191-5p, miR-4435, and miR-4465 in malignant and benign breast tumors

Objective(s):

MicroRNAs (miRs) are a class of small non-coding RNAs which are associated with tumor growth and progression. In the present study, we assessed the expression of selected miRs in malignant, benign, and adjacent normal breast tissues.

Materials and Methods:

The expression of miR-1297, miR-3191-5P, miR-4435, and miR-4465 were evaluated in malignant (n=50), benign (n=35), and adjacent normal breast tissues (n=20) using qRT-PCR. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were generated for evaluating the diagnostic values of miRs. To evaluate diagnostic efficacy, miRs-based score was obtained using the logistic regression model.

Results:

Among malignant tumors, the expression of miR-1297, miR-3191-5p, and miR-4435 was significantly lower (P=0.024, P<0.001 and P=0.031), respectively. The expression of miR-4465 was higher (P=0.023) than that of normal tissue. The expression of these miRs was lower than those of benign tumors (P<0.01, P<0.001, P<0.0001, and P<0.01, respectively). We observed a positive correlation between miR-4465 expression levels and tumor stage (P=0.042) and a negative correlation with grade and Ki-67 score (P<0.05). The AUCs for miR-1297, miR-3191-5p, miR-4435, and miR-4465 in malignant tumors versus normal tissues were 0.784, 0.700, 0.976, and 0.865 and versus benign tumors they were 0.938, 0.857, 0.981, and 0.785, respectively. The optimal logit(P) value of 0.262 distinguished malignant from normal subjects with a sensitivity of 0.91, specificity of 0.85, and an overall accuracy of 0.89.

Conclusion:

The panel of these miRs are suggested as possible onco-miRs(miR-4465) or tumor suppressor-miRs (miR-3191-5P, miR-1297, miR-4435). Overall, our results indicated that these miRs could be introduced as diagnostic biomarkers in breast cancer patients.

MicroRNAs and metastasis: small RNAs play big roles

MicroRNAs (miRNAs) are small non-coding RNAs regulating post-transcriptional gene expression. They play important roles in many biological processes under physiological or pathological conditions, including development, metabolism, tumorigenesis, metastasis, and immune response. Over the past 15 years, significant insights have been gained into the roles of miRNAs in cancer. Depending on the cancer type, miRNAs can act as oncogenes, tumor suppressors, or metastasis regulators. In this review, we focus on the role of miRNAs as components of molecular networks regulating metastasis. These miRNAs, termed metastamiRs, promote or inhibit metastasis through various mechanisms, including regulation of migration, invasion, colonization, cancer stem cell properties, epithelial-mesenchymal transition, and microenvironment. Some of these metastamiRs represent attractive therapeutic targets for cancer treatment.

miRNA-223 at the crossroads of inflammation and cancer

miR-223 is an evolutionarily conserved anti-inflammatory microRNA primarily expressed in myeloid cells. miR-223 post-transcriptionally regulates many genes essential in inflammation, cell proliferation, and invasion. Recent studies show that miR-223 is either endogenously expressed or transferred in exosomes or extracellular vesicles to non-phagocytic cells including cancer cells, where it exerts biological functions. In cancerous cells, miR-223 acts either as an oncomiR promoting tumors or as a tumor suppressor in a context-dependent manner. Taken together, miR-223 can regulate tumorigenesis at multiple levels, including by suppressing the inflammatory tumor microenvironment and modulating malignancy of cancer cells.

OMCD: OncomiR Cancer Database

Background

microRNAs (miRNAs) are crucially important in the development of cancer. Their dysregulation, commonly observed in various types of cancer, is largely cancer-dependent. Thus, to understand the tumor biology and to develop accurate and sensitive biomarkers, we need to understand pan-cancer miRNA expression.

Constructions

At the University of Minnesota, we developed the OncomiR Cancer Database (OMCD), hosted on a web server, which allows easy and systematic comparative genomic analyses of miRNA sequencing data derived from more than 9500 cancer patients tissue samples available in the Cancer Genome Atlas (TCGA). OMCD includes associated clinical information and is searchable by organ-specific terms common to the TCGA.

Conclusions

Freely available to all users (www.oncomir.umn.edu/omcd/), OMCD enables (1) simple visualization of TCGA miRNA sequencing data, (2) statistical analysis of differentially expressed miRNAs for each cancer type, and (3) exploration of miRNA clusters across cancer types.

Database URL

www.oncomir.umn.edu/omcd

OncomiR or antioncomiR: Role of miRNAs in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a hematopoietic progenitor/stem cell disorder in which neoplastic myeloblasts are stopped at an immature stage of differentiation and lost the normal ability of proliferation and apoptosis. MicroRNAs (miRNAs) are small noncoding, single-stranded RNA molecules that can mediate the expression of target genes. While miRNAs mean to contribute the developments of normal functions, abnormal expression of miRNAs and regulations on their corresponding targets have often been found in the developments of AML and described in recent years. In leukemia, miRNAs may function as regulatory molecules, acting as oncogenes or tumor suppressors. Overexpression of miRNAs can down-regulate tumor suppressors or other genes involved in cell differentiation, thereby contributing to AML formation. Similarly, miRNAs can down-regulate different proteins with oncogenic activity as tumor suppressors. We herein review the current data on miRNAs, specifically their targets and their biological function based on apoptosis in the development of AML.

Antagonizing miR-455-3p inhibits chemoresistance and aggressiveness in esophageal squamous cell carcinoma

Background

The plasticity of cancer stem cells (CSCs)/tumor-initiating cells (T-ICs) suggests that multiple CSC/T-IC subpopulations exist within a tumor and that multiple oncogenic pathways collaborate to maintain the CSC/T-IC state. Here, we aimed to identify potential therapeutic targets that concomitantly regulate multiple T-IC subpopulations and CSC/T-IC-associated pathways.

Methods

A chemoresistant patient-derived xenograft (PDX) model of human esophageal squamous cell carcinoma (ESCC) was employed to identify microRNAs that contribute to ESCC aggressiveness. The oncogenic effects of microRNA-455-3p (miR-455-3p) on ESCC chemoresistance and tumorigenesis were examined by in vivo and in vitro chemoresistance, tumorsphere formation, side-population, and in vivo limiting dilution assays. The roles of miR-455-3p in activation of the Wnt/β-catenin and transforming growth factor-β (TGF-β)/Smad pathways were determined by luciferase and RNA immunoprecipitation assays.

Results

We found that miR-455-3p played essential roles in ESCC chemoresistance and tumorigenesis. Treatment with a miR-455-3p antagomir dramatically chemosensitized ESCC cells and reduced the subpopulations of CD90⁺ and CD271⁺ T-ICs via deactivation of multiple stemness-associated pathways, including Wnt/β-catenin and TGF-β signaling. Importantly, miR-455-3p exhibited aberrant upregulation in various human cancer types, and was significantly associated with decreased overall survival of cancer patients.

Conclusions

Our results demonstrate that miR-455-3p functions as an oncomiR in ESCC progression and may provide a potential therapeutic target to achieve better clinical outcomes in cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0669-9) contains supplementary material, which is available to authorized users.

Role of microRNAs in translation regulation and cancer

MicroRNAs (miRNAs) are pervasively expressed and regulate most biological functions. They function by modulating transcriptional and translational programs and therefore they orchestrate both physiological and pathological processes, such as development, cell differentiation, proliferation, apoptosis and tumor growth. miRNAs work as small guide molecules in RNA silencing, by negatively regulating the expression of several genes both at mRNA and protein level, by degrading their mRNA target and/or by silencing translation. One of the most recent advances in the field is the comprehension of their role in oncogenesis. The number of miRNA genes is increasing and an alteration in the level of miRNAs is involved in the initiation, progression and metastases formation of several tumors. Some tumor types show a distinct miRNA signature that distinguishes them from normal tissues and from other cancer types. Genetic and biochemical evidence supports the essential role of miRNAs in tumor development. Although the abnormal expression of miRNAs in cancer cells is a widely accepted phenomenon, the cause of this dysregulation is still unknown. Here, we discuss the biogenesis of miRNAs, focusing on the mechanisms by which they regulate protein synthesis. In addition we debate on their role in cancer, highlighting their potential to become therapeutic targets.

Targeting miRNAs by polyphenols: Novel therapeutic strategy for cancer

In the recent years, polyphenols have gained significant attention in scientific community owing to their potential anticancer effects against a wide range of human malignancies. Epidemiological, clinical and preclinical studies have supported that daily intake of polyphenol-rich dietary fruits have a strong co-relationship in the prevention of different types of cancer. In addition to direct antioxidant mechanisms, they also regulate several therapeutically important oncogenic signaling and transcription factors. However, after the discovery of microRNA (miRNA), numerous studies have identified that polyphenols, including epigallocatechin-3-gallate, genistein, resveratrol and curcumin exert their anticancer effects by regulating different miRNAs which are implicated in all the stages of cancer. MiRNAs are short, non-coding endogenous RNA, which silence the gene functions by targeting messenger RNA (mRNA) through degradation or translation repression. However, cancer associated miRNAs has emerged only in recent years to support its applications in cancer therapy. Preclinical experiments have suggested that deregulation of single miRNA is sufficient for neoplastic transformation of cells. Indeed, the widespread deregulation of several miRNA profiles of tumor and healthy tissue samples revealed the involvement of many types of miRNA in the development of numerous cancers. Hence, targeting the miRNAs using polyphenols will be a novel and promising strategy in anticancer chemotherapy. Herein, we have critically reviewed the potential applications of polyphenols on various human miRNAs, especially which are involved in oncogenic and tumor suppressor pathways.

The miRacle in Pancreatic Cancer by miRNAs: Tiny Angels or Devils in Disease Progression

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with increasing incidence and high mortality. Surgical resection is the only potentially curative treatment of patients with PDAC. Because of the late presentation of the disease, about 20 percent of patients are candidates for this treatment. The average survival of resected patients is between 12 and 20 months, with a high probability of relapse. Standard chemo and radiation therapies do not offer significant improvement of the survival of these patients. Furthermore, novel treatment options aimed at targeting oncogenes or growth factors in pancreatic cancer have proved unsuccessful. Thereby, identifying new biomarkers that can detect early stages of this disease is of critical importance. Among these biomarkers, microRNAs (miRNAs) have supplied a profitable recourse and become an attractive focus of research in PDAC. MiRNAs regulate many genes involved in the development of PDAC through mRNA degradation or translation inhibition. The possibility of intervention in the molecular mechanisms of miRNAs regulation could begin a new generation of PDAC therapies. This review summarizes the reports describing miRNAs involvement in cellular processes involving pancreatic carcinogenesis and their utility in diagnosis, survival and therapeutic potential in pancreatic cancer.

Small molecules targeting microRNA for cancer therapy: Promises and obstacles

Aberrant expression of miRNAs is critically implicated in cancer initiation and progression. Therapeutic approaches focused on regulating miRNAs are therefore a promising approach for treating cancer. Antisense oligonucleotides, miRNA sponges, and CRISPR/Cas9 genome editing systems are being investigated as tools for regulating miRNAs. Despite the accruing insights in the use of these tools, delivery concerns have mitigated clinical application of such systems. In contrast, little attention has been given to the potential of small molecules to modulate miRNA expression for cancer therapy. In these years, many researches proved that small molecules targeting cancer-related miRNAs might have greater potential for cancer treatment. Small molecules targeting cancer related miRNAs showed significantly promising results in different cancer models. However, there are still several obstacles hindering the progress and clinical application in this area. This review discusses the development, mechanisms and application of small molecules for modulating oncogenic miRNAs (oncomiRs). Attention has also been given to screening technologies and perspectives aimed to facilitate clinical translation for small molecule-based miRNA therapeutics.

Therapeutic Opportunities for Targeting microRNAs in Cancer

MicroRNAs (miRNAs) are small noncoding RNAs that can function as either powerful tumor promoters or suppressors in numerous types of cancer. The ability of miRs to target multiple genes and biological signaling pathways has created intense interest in their potential clinical utility as predictive and diagnostic biomarkers, and as innovative therapeutic agents. Recently, accumulating preclinical studies have illustrated the feasibility of slowing tumor progression by either overexpressing tumor suppressive miRNAs, or by neutralizing the activities of oncogenic miRNAs in cell- and animal-based models of cancer. Here we highlight prominent miRNAs that may represent potential therapeutic targets in human malignancies, as well as review current technologies available for inactivating or restoring miRNA activity in clinical settings.

MicroRNAS in endometrial cancer: recent advances and potential clinical applications

Endometrial cancer is a common malignant gynecological tumor, but there are few biomarkers that are useful for early and accurate diagnosis and few treatments other than surgery. However, use of microRNAs (miRNAs) that induces gene downregulation in cells may permit effective and minimally invasive diagnosis and treatment. In endometrial cancer cells, expression levels of miRNAs including miR-185, miR-210 and miR-423 are upregulated and those of miR-let7e, miR-30c and miR-221 are downregulated compared to normal tissues, and these miRNAs are involved in carcinogenesis, invasion and metastasis. miRNAs with expression changes such as miR-181b, miR-324-3p and miR-518b may be used as prognostic biomarkers and transfection of miR-152 may inhibit cancer growth. However, most current studies of miRNAs are at a basic level and further work is needed to establish clinical applications targeting miRNAs.

Therapeutic Opportunities for Targeting microRNAs in Cancer

MicroRNAs (miRNAs) are small noncoding RNAs that can function as either powerful tumor promoters or suppressors in numerous types of cancer. The ability of miRs to target multiple genes and biological signaling pathways has created intense interest in their potential clinical utility as predictive and diagnostic biomarkers, and as innovative therapeutic agents. Recently, accumulating preclinical studies have illustrated the feasibility of slowing tumor progression by either overexpressing tumor suppressive miRNAs, or by neutralizing the activities of oncogenic miRNAs in cell- and animal-based models of cancer. Here we highlight prominent miRNAs that may represent potential therapeutic targets in human malignancies, as well as review current technologies available for inactivating or restoring miRNA activity in clinical settings.