MiR-296-3p regulates cell growth and multi-drug resistance of human glioblastoma by targeting ether-à-go-go (EAG1)

Circ_0004851 regulates the molecular mechanism of miR-296-3p/FGF11 in the influence of high iodine on PTC

The prevalence of papillary thyroid cancer (PTC) has been rising in recent years. Despite its relatively low mortality, PTC frequently metastasizes to lymph nodes and often recurs, posing significant health and economic burdens. The role of iodine in the pathogenesis and advancement of thyroid cancer remains poorly understood. Circular RNAs (circRNAs) are recognized to function as competing endogenous RNAs (ceRNAs) that modulate gene expression and play a role in various cancer stages. Consequently, this research aimed to elucidate the mechanism by which circRNA influences the impact of iodine on PTC. Our research indicates that high iodine levels can exacerbate the malignancy of PTC via the circ_0004851/miR-296-3p/FGF11 axis. These insights into iodine's biological role in PTC and the association of circRNA with the disease could pave the way for novel biomarkers and potentially effective therapeutic strategies to mitigate PTC progression.

MicroRNAs in adult high-grade gliomas: Mechanisms of chemotherapeutic resistance and their clinical relevance

Notorious for its high mortality rate, the current standard treatment for high-grade gliomas remains a challenge. This is largely due to the complex heterogeneity of the tumour coupled with dysregulated molecular mechanisms leading to the development of drug resistance. In recent years, microRNAs (miRNAs) have been considered to provide important information about the pathogenesis and prognostication of gliomas. miRNAs have been shown to play a specific role in promoting oncogenesis and regulating resistance to anti-glioma therapeutic agents through diverse cellular mechanisms. These include regulation of apoptosis, alterations in drug efflux pathways, enhanced activation of oncogenic signalling pathways, Epithelial-Mesenchymal Transition-like process (EMT-like) and a few others. With this knowledge, upregulation or inhibition of selected miRNAs can be used to directly affect drug resistance in glioma cells. Moreover, the clinical use of miRNAs in glioma management is becoming increasingly valuable. This comprehensive review delves into the role of miRNAs in drug resistance in high-grade gliomas and underscores their clinical significance. Our analysis has identified a distinct cluster of oncogenic miRNAs (miR-9, miR-21, miR-26a, miR-125b, and miR-221/222) and tumour suppressive miRNAs (miR-29, miR-23, miR-34a-5p, miR 181b-5p, miR-16-5p, and miR-20a) that consistently emerge as key players in regulating drug resistance across various studies. These miRNAs have demonstrated significant clinical relevance in the context of resistance to anti-glioma therapies. Additionally, the clinical significance of miRNA analysis is emphasised, including their potential to serve as clinical biomarkers for diagnosing, staging, evaluating prognosis, and assessing treatment response in gliomas.

The role of CEMIP in cancers and its transcriptional and post-transcriptional regulation

CEMIP is a protein known for inducing cell migration and binding to hyaluronic acid. Functioning as a hyaluronidase, CEMIP primarily facilitates the breakdown of the extracellular matrix component, hyaluronic acid, thereby regulating various signaling pathways. Recent evidence has highlighted the significant role of CEMIP in different cancers, associating it with diverse pathological states. While identified as a biomarker for several diseases, CEMIP's mechanism in cancer seems distinct. Accumulating data suggests that CEMIP expression is triggered by chemical modifications to itself and other influencing factors. Transcriptionally, chemical alterations to the CEMIP promoter and involvement of transcription factors such as AP-1, HIF, and NF-κB regulate CEMIP levels. Similarly, specific miRNAs have been found to post-transcriptionally regulate CEMIP. This review provides a comprehensive summary of CEMIP's role in various cancers and explores how both transcriptional and post-transcriptional mechanisms control its expression.

Extracellular vesicle-encapsulated microRNA-296-3p from cancer-associated fibroblasts promotes ovarian cancer development through regulation of the PTEN/AKT and SOCS6/STAT3 pathways

Cancer-associated fibroblasts (CAFs), as important components of the tumor microenvironment, can regulate intercellular communication and tumor development by secreting extracellular vesicles (EVs). However, the role of CAF-derived EVs in ovarian cancer has not been fully elucidated. Here, using an EV-microRNA sequencing analysis, we reveal specific overexpression of microRNA (miR)-296-3p in activated CAF-derived EVs, which can be transferred to tumor cells to regulate the malignant phenotypes of ovarian cancer cells. Moreover, overexpression of miR-296-3p significantly promotes the proliferation, migration, invasion, and drug resistance of ovarian cancer cells in vitro, as well as tumor growth in vivo, while its inhibition has the opposite effects. Further mechanistic studies reveal that miR-296-3p promotes ovarian cancer progression by directly targeting PTEN and SOCS6 and activating AKT and STAT3 signaling pathways. Importantly, increased expression of miR-296-3p encapsulated in plasma EVs is closely correlated with tumorigenesis and chemoresistance in patients with ovarian cancer. Our results highlight the cancer-promoting role of CAF-derived EVs carrying miR-296-3p in ovarian cancer progression for the first time, and suggest that miR-296-3p encapsulated in CAF-derived EVs could be a diagnostic biomarker and therapeutic target for ovarian cancer.

SNHG25 promotes colorectal cancer metastasis by regulating MMP2

LncRNA has been shown to play an important role in tumors, but the functions of most lncRNAs in colorectal cancer is not clear. By analyzing the transcriptome data of tumor tissues and adjacent tissues, we identified the lncRNA profiles that were abnormally expressed in colorectal cancer and selected the abnormally highly expressed lncRNA SNHG25 for further study. The functional assays showed that after knocking down SNHG25, the metastatic ability of colorectal cancer cells was significantly reduced. Western blot and immunofluorescence assays showed that inhibiting SNHG25 would affect the expression of Vimentin and E-Cadherin. In terms of mechanism, the results of RNA pull down assays, RNA immunoprecipitation (RIP) assays and dual luciferase reporter assays showed that SNHG25 could promote MMP2 expression by adsorbing miR-296-3p. In addition, chromatin immunoprecipitation (ChIP) assays and promoter luciferase reporter assays revealed that PAX5 could activate the transcription of SNHG25 in colorectal cancer cells. Our study proved that SNHG25 acts a pro-metastasis role in colorectal cancer, enriching the theory of the functions of lncRNA in colorectal cancer.

Fluorescent membrane potential assay for drug screening on Kv10.1 channel: identification of BL-1249 as a channel activator

Resting membrane potential is a bioelectric property of all cells. Multiple players govern this property, the ion channels being the most important. Ion channel dysfunction can affect cells' resting membrane potential and could be associated with numerous diseases. Therefore, the drug discovery focus on ion channels has increased yearly. In addition to patch-clamp, cell-based fluorescent assays have shown a rapid and reliable method for searching new ion channel modulators. Here, we used a cell-based membrane potential assay to search for new blockers of the Kv10.1, a potassium channel strongly associated with cancer progression and a promising target in anticancer therapy. We found that fluoxetine and miconazole can inhibit the Kv10.1 channel in the micromolar range. In contrast, BL-1249 potentiates Kv10.1 currents in a dose-dependent manner, becoming the first molecule described as an activator of the channel. These results demonstrate that cell-based membrane potential assay can accelerate the discovery of new Kv10.1 modulators.

Potassium Ion Channels in Glioma: From Basic Knowledge into Therapeutic Applications

Ion channels, specifically those controlling the flux of potassium across cell membranes, have recently been shown to exhibit an important role in the pathophysiology of glioma, the most common primary central nervous system tumor with a poor prognosis. Potassium channels are grouped into four subfamilies differing by their domain structure, gating mechanisms, and functions. Pertinent literature indicates the vital functions of potassium channels in many aspects of glioma carcinogenesis, including proliferation, migration, and apoptosis. The dysfunction of potassium channels can result in pro-proliferative signals that are highly related to calcium signaling as well. Moreover, this dysfunction can feed into migration and metastasis, most likely by increasing the osmotic pressure of cells allowing the cells to initiate the "escape" and "invasion" of capillaries. Reducing the expression or channel blockage has shown efficacy in reducing the proliferation and infiltration of glioma cells as well as inducing apoptosis, priming several approaches to target potassium channels in gliomas pharmacologically. This review summarizes the current knowledge on potassium channels, their contribution to oncogenic transformations in glioma, and the existing perspectives on utilizing them as potential targets for therapy.

Circular RNA circFBXO7 attenuates non-small cell lung cancer tumorigenesis by sponging miR-296-3p to facilitate KLF15-mediated transcriptional activation of CDKN1A

BACKGROUND

Accumulating evidence indicates that circular RNAs (circRNAs) play important roles in various cancers. Hsa_circ_0008832 (circFBXO7) is a circRNA generated from the second exon of the human F-box only protein 7 (FBXO7). Mouse circFbxo7 is a circRNA generated from the second exon of mouse F-box only protein 7 (Fbxo7). The role of human circFBXO7 and mouse circFbxo7 in non-small cell lung cancer (NSCLC) has not been reported.

METHODS

The expression of circFBXO7 was measured by quantitative real-time PCR. Survival analysis was performed to explore the association between the expression of circFBXO7 and the prognosis of patients with NSCLC. Lung cancer cell lines were transfected with plasmids. Cell proliferation, cell cycle, and tumorigenesis were evaluated to assess the effects of circFBXO7. Fluorescence in situ hybridization assay was used to identify the location of circFBXO7 and circFbxo7 in human and mouse lung cancer cells. Luciferase reporter assay was conducted to confirm the relationship between circFBXO7 and microRNA.

RESULTS

In this study, we found that circFBXO7 was downregulated in NSCLC tissues and cell lines. NSCLC patients with high circFBXO7 expression had prolonged overall survival. Overexpression of circFBXO7 inhibited cell proliferation both in vitro and in vivo. Mechanistically, we demonstrated that circFBXO7 upregulated the expression of miR-296-3p target gene Krüppel-like factor 15 (KLF15) and KLF15 transactivated the expression of CDKN1A.

CONCLUSIONS

CircFBXO7 acts as a tumor suppressor by a novel circFBXO7/miR-296-3p/KLF15/CDKN1A axis, which may serve as a potential biomarker and therapeutic target for NSCLC.

Ion Channels in Gliomas-From Molecular Basis to Treatment

Ion channels provide the basis for the nervous system's intrinsic electrical activity. Neuronal excitability is a characteristic property of neurons and is critical for all functions of the nervous system. Glia cells fulfill essential supportive roles, but unlike neurons, they also retain the ability to divide. This can lead to uncontrolled growth and the formation of gliomas. Ion channels are involved in the unique biology of gliomas pertaining to peritumoral pathology and seizures, diffuse invasion, and treatment resistance. The emerging picture shows ion channels in the brain at the crossroads of neurophysiology and fundamental pathophysiological processes of specific cancer behaviors as reflected by uncontrolled proliferation, infiltration, resistance to apoptosis, metabolism, and angiogenesis. Ion channels are highly druggable, making them an enticing therapeutic target. Targeting ion channels in difficult-to-treat brain tumors such as gliomas requires an understanding of their extremely heterogenous tumor microenvironment and highly diverse molecular profiles, both representing major causes of recurrence and treatment resistance. In this review, we survey the current knowledge on ion channels with oncogenic behavior within the heterogeneous group of gliomas, review ion channel gene expression as genomic biomarkers for glioma prognosis and provide an update on therapeutic perspectives for repurposed and novel ion channel inhibitors and electrotherapy.

Hsa_Circ_0005044 Promotes Osteo/Odontogenic Differentiation of Dental Pulp Stem Cell Via Modulating miR-296-3p/FOSL1

Circular RNAs (circRNAs) are a form of RNAs that lack coding potential. The role of such circRNAs in dental pulp stem cell (DPSC) osteo/odontogenic differentiation remains to be determined. In this study, circRNA expression profiles in DPSC osteo/odontogenic differentiation process were analyzed by RNA-seq. qRT-PCR was used to confirm the differential expression of circ_0005044, miR-296-3p, and FOSL1 in DPSC osteogenic differentiation process. Circ_0005044, miR-296-3p, and FOSL1 were knocked down or overexpressed. Osteoblastic activity and associated mineral activity were monitored via alkaline phosphatase (ALP) and alizarin red S (ARS) staining. Interactions between miR-296-3p, circ_0005044, and FOSL1 were assessed through luciferase reporter assays. Finally, an in vivo system was used to confirm the relevance of circ_0005044 to osteoblastic differentiation. As results, we detected significant circ_0005044 and FOSL1 upregulation in DPSC osteo/odontogenic differentiation process, as well as concomitant miR-296-3p downregulation. When knocking down circ_0005044 or overexpressed miR-296-3p, this significantly inhibited osteogenesis. Luciferase reporter assay confirmed that miR-296-3p was capable of binding to conserved sequences in the wild-type forms of both the circ_0005044 and FOSL1. Furthermore, knocking down circ_0005044 in vivo significantly attenuated bone formation. Therefore, the circ_0005044/miR-2964-3p/FOSL1 axis regulates DPSC osteo/odontogenic differentiation, which may provide potential molecular targets for dental-pulp complex regeneration.

New Diarylamine KV10.1 Inhibitors and Their Anticancer Potential

Expression of the voltage-gated potassium channel K_V10.1 (Eag1) has been detected in over 70% of human cancers, making the channel a promising new target for new anticancer drug discovery. A new structural class of K_V10.1 inhibitors was prepared by structural optimisation and exploration of the structure–activity relationship of the previously published hit compound ZVS-08 (1) and its optimised analogue 2. The potency and selectivity of the new inhibitors between K_V10.1 and hERG were investigated using whole-cell patch-clamp experiments. We obtained two new optimised K_V10.1 inhibitors, 17a and 18b, with improved nanomolar IC₅₀ values of 568 nM and 214 nM, respectively. Compound 17a exhibited better ratio between IC₅₀ values for hEAG1 and hERG than previously published diarylamine inhibitors. Compounds 17a and 18b moderately inhibited the growth of the K_V10.1-expressing cell line MCF-7 in two independent assays. In addition, 17a and 18b also inhibited the growth of hERG-expressing Panc-1 cells with higher potency compared with MCF-7 cells. The main obstacle for newly developed diarylamine K_V10.1 inhibitors remains the selectivity toward the hERG channel, which needs to be addressed with targeted drug design strategies in the future.

Recent insights into the microRNA-dependent modulation of gliomas from pathogenesis to diagnosis and treatment

Gliomas are the most lethal primary brain tumors in adults. These highly invasive tumors have poor 5-year survival for patients. Gliomas are principally characterized by rapid diffusion as well as high levels of cellular heterogeneity. However, to date, the exact pathogenic mechanisms, contributing to gliomas remain ambiguous. MicroRNAs (miRNAs), as small noncoding RNAs of about 20 nucleotides in length, are known as chief modulators of different biological processes at both transcriptional and posttranscriptional levels. More recently, it has been revealed that these noncoding RNA molecules have essential roles in tumorigenesis and progression of multiple cancers, including gliomas. Interestingly, miRNAs are able to modulate diverse cancer-related processes such as cell proliferation and apoptosis, invasion and migration, differentiation and stemness, angiogenesis, and drug resistance; thus, impaired miRNAs may result in deterioration of gliomas. Additionally, miRNAs can be secreted into cerebrospinal fluid (CSF), as well as the bloodstream, and transported between normal and tumor cells freely or by exosomes, converting them into potential diagnostic and/or prognostic biomarkers for gliomas. They would also be great therapeutic agents, especially if they could cross the blood–brain barrier (BBB). Accordingly, in the current review, the contribution of miRNAs to glioma pathogenesis is first discussed, then their glioma-related diagnostic/prognostic and therapeutic potential is highlighted briefly.

The Kv10.1 Channel: A Promising Target in Cancer

Carcinogenesis is a multistage process involving the dysregulation of multiple genes, proteins, and pathways that make any normal cell acquire a cancer cell phenotype. Therefore, it is no surprise that numerous ion channels could be involved in this process. Since their discovery and subsequent cloning, ion channels have been established as therapeutic targets in excitable cell pathologies (e.g., cardiac arrhythmias or epilepsy); however, their involvement in non-excitable cell pathologies is relatively recent. Among all ion channels, the voltage-gated potassium channels Kv10.1 have been established as a promising target in cancer treatment due to their high expression in tumoral tissues compared to low levels in healthy tissues.

Integrative analysis of TCGA data identifies miRNAs as drug-specific survival biomarkers

Biomarkers predictive of drug-specific outcomes are important tools for personalized medicine. In this study, we present an integrative analysis to identify miRNAs that are predictive of drug-specific survival outcome in cancer. Using the clinical data from TCGA, we defined subsets of cancer patients who suffered from the same cancer and received the same drug treatment, which we call cancer-drug groups. We then used the miRNA expression data in TCGA to evaluate each miRNA’s ability to predict the survival outcome of patients in each cancer-drug group. As a result, the identified miRNAs are predictive of survival outcomes in a cancer-specific and drug-specific manner. Notably, most of the drug-specific miRNA survival markers and their target genes showed consistency in terms of correlations in their expression and their correlations with survival. Some of the identified miRNAs were supported by published literature in contexts of various cancers. We explored several additional breast cancer datasets that provided miRNA expression and survival data, and showed that our drug-specific miRNA survival markers for breast cancer were able to effectively stratify the prognosis of patients in those additional datasets. Together, this analysis revealed drug-specific miRNA markers for cancer survival, which can be promising tools toward personalized medicine.

Voltage-Gated Potassium Channels Beyond the Action Potential

Bioelectricity goes far beyond electrical signaling in the nervous system, but this was initially not obvious for me. This article describes the journey from studying the biophysics of ion channels in classical electrically excitable tissues to focusing on the pathogenic roles of the Kv10.1 potassium channel in cancers.

Hippo Pathway in Regulating Drug Resistance of Glioblastoma

Glioblastoma (GBM) represents the most common and malignant tumor of the Central Nervous System (CNS), affecting both children and adults. GBM is one of the deadliest tumor types and it shows a strong multidrug resistance (MDR) and an immunosuppressive microenvironment which remain a great challenge to therapy. Due to the high recurrence of GBM after treatment, the understanding of the chemoresistance phenomenon and how to stimulate the antitumor immune response in this pathology is crucial. The deregulation of the Hippo pathway is involved in tumor genesis, chemoresistance and immunosuppressive nature of GBM. This pathway is an evolutionarily conserved signaling pathway with a kinase cascade core, which controls the translocation of YAP (Yes-Associated Protein)/TAZ (Transcriptional Co-activator with PDZ-binding Motif) into the nucleus, leading to regulation of organ size and growth. With this review, we want to highlight how chemoresistance and tumor immunosuppression work in GBM and how the Hippo pathway has a key role in them. We linger on the role of the Hippo pathway evaluating the effect of its de-regulation among different human cancers. Moreover, we consider how different pathways are cross-linked with the Hippo signaling in GBM genesis and the hypothetical mechanisms responsible for the Hippo pathway activation in GBM. Furthermore, we describe various drugs targeting the Hippo pathway. In conclusion, all the evidence described largely support a strong involvement of the Hippo pathway in gliomas progression, in the activation of chemoresistance mechanisms and in the development of an immunosuppressive microenvironment. Therefore, this pathway is a promising target for the treatment of high grade gliomas and in particular of GBM.

Overcoming challenges of HERG potassium channel liability through rational design: Eag1 inhibitors for cancer treatment

Two decades of research have proven the relevance of ion channel expression for tumor progression in virtually every indication, and it has become clear that inhibition of specific ion channels will eventually become part of the oncology therapeutic arsenal. However, ion channels play relevant roles in all aspects of physiology, and specificity for the tumor tissue remains a challenge to avoid undesired effects. Eag1 (K_V 10.1) is a voltage-gated potassium channel whose expression is very restricted in healthy tissues outside of the brain, while it is overexpressed in 70% of human tumors. Inhibition of Eag1 reduces tumor growth, but the search for potent inhibitors for tumor therapy suffers from the structural similarities with the cardiac HERG channel, a major off-target. Existing inhibitors show low specificity between the two channels, and screenings for Eag1 binders are prone to enrichment in compounds that also bind HERG. Rational drug design requires knowledge of the structure of the target and the understanding of structure-function relationships. Recent studies have shown subtle structural differences between Eag1 and HERG channels with profound functional impact. Thus, although both targets' structure is likely too similar to identify leads that exclusively bind to one of the channels, the structural information combined with the new knowledge of the functional relevance of particular residues or areas suggests the possibility of selective targeting of Eag1 in cancer therapies. Further development of selective Eag1 inhibitors can lead to first-in-class compounds for the treatment of different cancers.

Meta-analysis of the clinicopathological significance of miRNA-145 in breast cancer

Low expression of tumor suppressor microRNA (miRNA) and high expression of carcinogenic miRNA promote the occurrence and progression of human cancer. Most studies show that miR-145 is a tumor suppressor miRNA, and is closely related to the clinicopathology of breast cancer. However, the results are still inconsistent. Therefore, we conducted a meta-analysis on the basis of eligible studies to summarize the possible correlation between miR-145 and the clinicopathology and prognosis of breast cancer. Using PubMed, Embase, Web of Science, Wanfang and CNKI, we searched all published papers written in either English or Chinese on miR-145 expression in breast cancer from 1990 to November 2019 for meta-analysis. We used standardized mean difference (SMD) to evaluate the differential expression of miR-145 in breast cancer tissues and adjacent normal tissues or normal breast tissues. We found that miR-145 expression was significantly lower in breast cancer tissues than that in adjacent normal tissues (SMD = −2.93, P<0.0001) and in healthy women (SMD = −0.52, P=0.009). miR-145 expression was lower in breast cancer patients with ER-positive (SMD = 0.65, P<0.001), HER-2-positive (SMD = −1.04, P<0.001), compared with their counterparts, respectively. In addition, breast cancer patients with low expression of miR-145 had larger tumor diameters (SMD = −1.97, P<0.001) and lymph node metastasis (SMD = −1.75, P<0.001) that are unfavorable prognostic factors. Conclusion: Low miR-145 is observed in breast cancer, which is closely related to molecular subtypes and unfavorable factors of breast cancer. These findings indicate that miR-145 is tumor suppressor miRNA, and may be a potential diagnostic and prognostic marker in breast cancer.

Modifications of Plasma Membrane Organization in Cancer Cells for Targeted Therapy

Modifications of the composition or organization of the cancer cell membrane seem to be a promising targeted therapy. This approach can significantly enhance drug uptake or intensify the response of cancer cells to chemotherapeutics. There are several methods enabling lipid bilayer modifications, e.g., pharmacological, physical, and mechanical. It is crucial to keep in mind the significance of drug resistance phenomenon, ion channel and specific receptor impact, and lipid bilayer organization in planning the cell membrane-targeted treatment. In this review, strategies based on cell membrane modulation or reorganization are presented as an alternative tool for future therapeutic protocols.

3D Pharmacophore-Based Discovery of Novel KV10.1 Inhibitors with Antiproliferative Activity

Simple Summary

A novel structural class of inhibitors of the voltage-gated potassium channel K_V10.1 was discovered by a ligand-based drug design method using a 3D pharmacophore model. The virtual screening hit compound ZVS-08 inhibited the channel in a voltage-dependent manner consistent with the action of a gating modifier. Structure–activity relationship studies revealed a nanomolar K_V10.1 inhibitor that is selective for some K_V and Na_V channels but exhibits significant inhibition of the hERG channel. K_V10.1 inhibitor 1 inhibited the growth of the MCF-7 cell line expressing high levels of K_V10.1 and low levels of hERG more potently than the Panc1 cell line (no K_V10.1 and high hERG expression). Moreover, the K_V10.1 inhibitor 1 induced significant apoptosis in tumour spheroids of Colo-357 cells. This study may provide a basis for the use of computational drug design methods for the discovery of novel K_V10.1 inhibitors as new promising anticancer drugs.

Abstract

(1) Background: The voltage-gated potassium channel K_V10.1 (Eag1) is considered a near- universal tumour marker and represents a promising new target for the discovery of novel anticancer drugs. (2) Methods: We utilized the ligand-based drug discovery methodology using 3D pharmacophore modelling and medicinal chemistry approaches to prepare a novel structural class of K_V10.1 inhibitors. Whole-cell patch clamp experiments were used to investigate potency, selectivity, kinetics and mode of inhibition. Anticancer activity was determined using 2D and 3D cell-based models. (3) Results: The virtual screening hit compound ZVS-08 discovered by 3D pharmacophore modelling exhibited an IC₅₀ value of 3.70 µM against K_V10.1 and inhibited the channel in a voltage-dependent manner consistent with the action of a gating modifier. Structural optimization resulted in the most potent K_V10.1 inhibitor of the series with an IC₅₀ value of 740 nM, which was potent on the MCF-7 cell line expressing high K_V10.1 levels and low hERG levels, induced significant apoptosis in tumour spheroids of Colo-357 cells and was not mutagenic. (4) Conclusions: Computational ligand-based drug design methods can be successful in the discovery of new potent K_V10.1 inhibitors. The main problem in the field of K_V10.1 inhibitors remains selectivity against the hERG channel, which needs to be addressed in the future also with target-based drug design methods.

Circular RNA circRUNX1 promotes papillary thyroid cancer progression and metastasis by sponging MiR-296-3p and regulating DDHD2 expression

Papillary thyroid cancer (PTC) has a continuously increasing incidence and imposes a heavy medical burden to individuals and society due to its high proportion of lymph node metastasis and recurrence in recent years. Circular RNAs, a class of noncoding RNAs, participate in the progression of many cancers, but the role of circRNAs in PTC is still rarely reported. In this study, circRNA deep sequencing was performed to identify differentially expressed circRNAs in PTC. CircRUNX1 was selected for its high expression in PTC, and circRUNX1 silencing was directly associated with the week potential for migration, invasion and proliferation of PTC in vivo and in vitro. Fluorescence in situ hybridization (FISH) was further used to confirm the cytoplasmic localization of circRUNX1, indicating the possible function of circRUNX1 as a ceRNAs in PTC progression through miRNA binding. MiR-296-3p was then confirmed to be regulated by circRUNX1 and to target DDHD domain containing 2 (DDHD2) by luciferase reporter assays. The strong antitumor effect of miR-296-3p and the tumor-promoting effect of DDHD2 were further investigated in PTC, indicating that circRUNX1 modulates PTC progression through the miR-296-3p/DDHD2 pathway. Overall, circRUNX1 plays an oncogenic role in PTC and provides a potentially effective therapeutic strategy for PTC progression.

HDAC3 deteriorates colorectal cancer progression via microRNA-296-3p/TGIF1/TGFβ axis

Background

The mechanism of histone deacetylase 3 (HDAC3) in colorectal cancer (CRC) has already been discussed. However, the feedback loop of HDAC3/microRNA (miR)-296-3p and transforming growth factor β-induced factor 1 (TGIF1) in CRC has not been explained clearly. Thus, the mainstay of this study is to delve out the mechanism of this axis in CRC.

Methods

To demonstrate that HDAC3 regulates the miR-296-3p/TGIF1/TGFβ axis and is involved in CRC progression, a series of cell biological, molecular and biochemical approaches were conducted from the clinical research level, in vitro experiments and in vivo experiments. These methods included RT-qPCR, Western blot assay, cell transfection, MTT assay, EdU assay, flow cytometry, scratch test, Transwell assay, dual luciferase reporter gene assay, chromatin immunoprecipitation, nude mouse xenograft, H&E staining and TUNEL staining.

Results

Higher HDAC3 and TGIF1 and lower miR-296-3p expression levels were found in CRC tissues. HDAC3 was negatively connected with miR-296-3p while positively correlated with TGIF1, and miR-296-3p was negatively connected with TGIF1. Depleted HDAC3 elevated miR-296-3p expression and reduced TGIF1 expression, decreased TGFβ pathway-related proteins, inhibited CRC proliferation, invasion, and migration in vitro and slowed down tumor growth and induction of apoptosis in vivo, which were reversed by miR-296-3p knockdown. Restored miR-296-3p suppressed TGIF1 and reduced TGFβ pathway-related proteins, inhibited CRC proliferation, invasion, and migration in vitro and slowed down tumor growth and induction of apoptosis in vivo, which were reversed by TGIF1 overexpression.

Conclusion

This study illustrates that down-regulation of HDAC3 or TGIF1 or up-regulation of miR-296-3p discourages CRC cell progression and slows down tumor growth, which guides towards a novel direction of CRC treatment.

Ion Channels and Their Role in the Pathophysiology of Gliomas

Malignant gliomas are the most common primary central nervous system tumors and their prognosis is very poor. In recent years, ion channels have been demonstrated to play important roles in tumor pathophysiology such as regulation of gene expression, cell migration, and cell proliferation. In this review, we summarize the current knowledge on the role of ion channels on the development and progression of gliomas. Cell volume changes through the regulation of ion flux, accompanied by water flux, are essential for migration and invasion. Signaling pathways affected by ion channel activity play roles in cell survival and cell proliferation. Moreover, ion channels are involved in glioma-related seizures, sensitivity to chemotherapy, and tumor metabolism. Ion channels are potential targets for the treatment of these lethal tumors. Despite our increased understanding of the contributions of ion channels to glioma biology, this field remains poorly studied. This review summarizes the current literature on this important topic.

miR-181a-5p inhibits the proliferation and invasion of drug-resistant glioblastoma cells by targeting F-box protein 11 expression

Glioblastoma (GBM) is the most common malignant primary tumor in the human central nervous system. The present study aimed to explore the molecular mechanism by which microRNA (miR)-181a-5p targets the F-box protein 11 (FBXO11) in glioma cells to inhibit cell proliferation and invasion. Reverse transcription-quantitative (RT-q)PCR was performed to detect the expression levels of miR-181a-5p in U251TR cells, U251 cells, primary GBM tissues and relapsed GBM tissues in order to determine the association between miR-181a-5p and the chemoresistance of GBM cells. The expression levels of miR-181a-5p in GBM cells were modulated via transfecting miR-181a-5p mimics and inhibitors. Cell Counting Kit-8 assays were undertaken to assess the effects of miR-181a-5p on drug sensitivity and proliferation of GBM cells. Wound healing assays were performed to examine the effects of miR-181a-5p on the migratory ability of GBM cells. Furthermore, the effects of miR-181a-5p on the invasive ability of GBM cells were analyzed using an in vitro invasion assay. Flow cytometry analysis was carried out to determine whether overexpression of miR-181a-5p can promote the apoptotic rate of GBM cells. RT-qPCR and western blotting were employed to detect the effects of miR-181a-5p on mRNA and protein expression of FBX011. miR-181a-5p exhibited low expression in resistant GBM cell lines and recurrent tumor tissues. Dual-luciferase reporter assays were utilized to detect luciferase activity to verify the targeted regulatory association between miR-181a-5p and FBXO11. Upregulation of miR-181a-5p promoted the sensitivity of GBM cells to temozolomide (TMZ), increased the apoptotic rate of GBM cells and significantly inhibited the invasive and migratory capacities of GBM cells. In drug-resistant glioma cells, compared with the miR-negative control group and the blank group, the expression of miR-181a-5p was significantly upregulated (P<0.01), while the expression of FBXO11 protein was downregulated. miR-181a-5p increased the sensitivity of GBM cells to TMZ. miR-181a-5p significantly inhibited the migratory and invasive capacities of GBM cells. miR-181a-5p may become a novel effective target for the treatment of GBM. The results of dual-luciferase reporter assays indicated that miR-181a-5p could target the 3′-untranslated region of FBXO11. The underlying mechanism may be targeted inhibition of FBXO11 gene expression, or may be associated with apoptosis.

CircPSMC3 alleviates the symptoms of PCOS by sponging miR-296-3p and regulating PTEN expression

Polycystic ovary syndrome (PCOS), the most common female endocrine disease that causes anovulatory infertility, still lacks promising strategy for the accurate diagnosis and effective therapeutics of PCOS attributed to its unclear aetiology. In this study, we determined the abnormal reduction in circPSMC3 expression by comparing the ovarian tissue samples of PCOS patients and normal individuals. The symptom relief caused by up-regulation of circPSMC3 in PCOS model mice suggested the potential for further study. In vitro functional experiments confirmed that circPSMC3 can inhibit cell proliferation and promote apoptosis by blocking the cell cycle in human-like granular tumour cell lines. Mechanism study revealed that circPSMC3 may play its role through sponging miR-296-3p to regulate PTEN expression. Collectively, we preliminarily characterized the role and possible insights of circPSMC3/miR-296-3p/PTEN axis in the proliferation and apoptosis of KGN cells. We hope that this work provides some original and valuable information for the research of circRNAs in PCOS, not only to better understand the pathogenesis but also to help provide new clues for seeking for the future therapeutic target of PCOS.

Potassium channels and their role in glioma: A mini review

K⁺ channels regulate a multitude of biological processes and play important roles in a variety of diseases by controlling potassium flow across cell membranes. They are widely expressed in the central and peripheral nervous system. As a malignant tumor derived from nerve epithelium, glioma has the characteristics of high incidence, high recurrence rate, high mortality rate, and low cure rate. Since glioma cells show invasive growth, current surgical methods cannot completely remove tumors. Adjuvant chemotherapy is still needed after surgery. Because the blood-brain barrier and other factors lead to a lower effective concentration of chemotherapeutic drugs in the tumor, the recurrence rate of residual lesions is extremely high. Therefore, new therapeutic methods are needed. Numerous studies have shown that different K⁺ channel subtypes are differentially expressed in glioma cells and are involved in the regulation of the cell cycle of glioma cells to arrest them at different stages of the cell cycle. Increasing evidence suggests that K⁺ channels express in glioma cells and regulate glioma cell behaviors such as cell cycle, proliferation and apoptosis. This review article aims to summarize the current knowledge on the function of K⁺ channels in glioma, suggests K⁺ channels participating in the development of glioma.

A Novel Anti-Kv10.1 Nanobody Fused to Single-Chain TRAIL Enhances Apoptosis Induction in Cancer Cells

Antibody-based therapies hold promise for a safe and efficient treatment of cancer. The identification of target tumor cells through a specific antigen enriched on their surface and the subsequent delivery of the therapeutic agent only to those cells requires, besides the efficacy of the therapeutic agent itself, the identification of an antigen enriched on the surface of tumor cells, the generation of high affinity antibodies against that antigen. We have generated single-domain antibodies (nanobodies) against the voltage-gated potassium channel Kv10.1, which outside of the brain is detectable almost exclusively in tumor cells. The nanobody with highest affinity was fused to an improved form of the tumor necrosis factor-related apoptosis inducing ligand TRAIL, to target this cytokine to the surface of tumor cells. The resulting construct, VHH-D9-scTRAIL, shows rapid and strong apoptosis induction in different tumor models in cell culture. The construct combines two sources of specificity, the expression of the antigen restricted to tumor cells and the tumor selectivity of TRAIL. Such specificity combined with the high affinity obtained through nanobodies make the novel agent a promising concept for cancer therapy.

miR‑296‑3p promotes the proliferation of glioblastoma cells by targeting ICAT

MicroRNAs (miRNA/miRs) serve an important function in the regulation of gene expression, and have been indicated to mediate a number of cellular biological processes, including cell proliferation, the cell cycle, cell apoptosis and cell differentiation. The altered expression of miRNAs has been revealed to result in a variety of human diseases, including glioblastoma multiforme (GBM). The present study indicated an increase in miR‑296‑3p in glioma tumor types compared with normal brain, particularly in the samples from patients with high grade GBM. Antagonizing miR‑296‑3p was demonstrated to induce cell growth arrest and cell cycle redistribution in U251 cells. The miR‑296‑3p antagonist altered the expression of a number of key genes that are involved in cell cycle control, including cyclin D1 and p21. Additionally, the decrease of miR‑296‑3p increased inhibitor of β‑catenin and T cell factor (ICAT) expression, and increased miR‑296‑3p‑inhibited ICAT expression in U251 cells. Bioinformatics analysis indicated that ICAT is a target gene of miR‑296‑3p, which was further validated using a dual‑luciferase reporter assay. Through the regulation of ICAT, the miR‑296‑3p antagonist decreased β‑catenin protein expression and increased the expression of its target genes. Silencing ICAT was indicated to reverse the miR‑296‑3p downregulation‑induced inactivation of Wnt signaling and cell growth arrest in glioma cells. The present study also indicated a negative correlation between ICAT mRNA levels and miR‑296‑3p levels in glioma tumor types. In conclusion, the present study identified an oncogenic function of miR‑296‑3p in glioblastoma via the direct regulation of ICAT.

miR-152-3p Sensitizes Glioblastoma Cells Towards Cisplatin Via Regulation Of SOS1

Background

Accumulating evidences suggest that microRNAs (miRNAs) play key roles in mediating glioblastoma progression. Decreased expression of miR-152-3p was reported in several cancer types including glioblastoma.

Methods

The sensitivity of glioblastoma cells to cisplatin was assessed by the cell counting kit-8 assay and flow cytometry analysis. The expression of miR-152-3p was determined by RT-qPCR method. Bioinformatic analysis, dual luciferase reporter assay and Western blot were used to explore the target gene of miR-152-3p. The association between miR-152-3p and SOS1 was confirmed in glioblastoma tissues by Pearson correlation analysis.

Results

In the current study, we discovered that overexpression of miR-152-3p increased cisplatin sensitivity while inhibition of miR-152-3p decreased cisplatin sensitivity in glioblastoma cells (T98G and U87). In addition, miR-152-3p augmented cell apoptosis induced by cisplatin treatment. It was further predicted and validated that SOS1, a protein involved in regulating chemotherapy sensitivity, was a direct target gene of miR-152-3p. SOS1 was proven to suppress the cytotoxic effect of cisplatin in glioblastoma. Transfection of recombinant SOS1 could effectively reverse the increased cisplatin sensitivity induced by miR-152-3p overexpression in T98G. Furthermore, overexpression of SOS1 reduced the percentage of apoptotic cells increased by miR-152-3p mimic in the presence of cisplatin in T98G. More importantly, a significant negative correlation between miR-152-3p levels and SOS1 levels was observed in glioblastoma tissues collected from 40 patients.

Conclusion

Our study identified miR-152-3p as a chemotherapy sensitizer in glioblastoma.

miR-802 inhibits the proliferation, invasion, and epithelial-mesenchymal transition of glioblastoma multiforme cells by directly targeting SIX4

It is well known that the sine oculis homeobox 4 (SIX4) expression is very relevant to the progression of multiple cancers. Moreover, we found that miR-802 could directly target the SIX4. However, the precise mechanism of miR-802 in glioblastoma multiforme (GBM) is still unknown. The aim of this study is to investigate the roles of miR-802/SIX4 axis in GBM. Here, our results showed that the SIX4 expression was obviously increased in GBM tissues and cell lines, and the miR-802 level was distinctly decreased. What is more, the SIX4 expression was negatively related to the miR-802 level in GBM tissues. Furthermore, increased miR-802 level evidently restrained the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of GBM cells. Next, we confirmed that miR-802 could directly target SIX4 by using luciferase reporter assay. Besides, the knockdown of SIX4 had the similar effects with miR-802 overexpression on GBM cells. The inhibitory effects of miR-802 mimic were partially blocked by SIX4 overexpression. Altogether, the overexpression of miR-802 restrained cell proliferation, invasion, and EMT of GBM cells via the regulation of SIX4. SIGNIFICANCE OF THE STUDY: An elevated expression of SIX4 has been observed in colorectal cancer and nonsmall cell lung cancer. However, the precise roles of SIX4 in GBM have not been elucidated. Our study for the first time demonstrated that SIX4 level was significantly upregulated in GBM. Additionally, the knockdown of SIX4 inhibited cell growth, invasion, and the EMT of GBM. Moreover, our data suggested a significant negative correlation between miR-802 and SIX4 expression in GBM. MiR-802 suppressed GBM cell proliferation, invasion, and EMT by directly targeting SIX4, which suggested important roles for miR-802/SIX4 axis in the GBM pathogenesis and its potential application in cancer therapy.

Circ-AKT3 inhibits clear cell renal cell carcinoma metastasis via altering miR-296-3p/E-cadherin signals

BACKGROUND

Circular RNA (circRNA) is a type of circular endogenous RNA produced by special selective splicing and participates in progression of diverse diseases. However, the role of circRNA in clear cell renal cell carcinoma (ccRCC) is still rarely reported.

METHODS

We detected lower circ-AKT3 expression in ccRCC using the circular RNA microarray. Then, qPCR array was applied to verify the expression of circ-AKT3 in between 60 ccRCC tissues and adjacent normal tissues, as well as ccRCC cell lines and human normal kidney cell (HK-2). We investigated the function of circ-AKT3 in ccRCC in vitro and in vivo and detected underlying mechanisms by Western blotting, bioinformatic analysis, RNA pull-down assay and luciferase reporter assay.

RESULTS

Circ-AKT3 was verified significantly downregulated in ccRCC. Knockdown of circ-AKT3 promoted ccRCC migration and invasion, while overexpression of circ-AKT3 suppressed ccRCC metastasis. Further, circ-AKT3/miR-296-3p/E-cadherin axis was shown responsible for circ-AKT3 inhibiting ccRCC metastasis.

CONCLUSION

Circ-AKT3 suppresses ccRCC metastasis by enforcing E-cadherin expression through competitively binding miR-296-3p. Circ-AKT3 may therefore serve as a novel therapeutic to better suppress ccRCC metastasis.

Serum microRNA-based prediction of responsiveness to eribulin in metastatic breast cancer

The identification of biomarkers for predicting the responsiveness to eribulin in patients with metastatic breast cancer pretreated with an anthracycline and a taxane remains an unmet need. Here, we established a serum microRNA (miRNA)-based prediction model for the emergence of new distant metastases after eribulin treatment. Serum samples were collected from metastatic breast cancer patients prior to eribulin treatment and comprehensively evaluated by miRNA microarray. The prediction model for estimating eribulin efficacy was established using the logistic LASSO regression model. Serum samples were collected from 147 patients, of which 52 developed at least one new distant metastasis after eribulin monotherapy and 95 did not develop new distant metastases. A combination of eight serum miRNAs (miR-4483, miR-8089, miR-4755-3p, miR-296-3p, miR-575, miR-4710, miR-5698 and miR-3160-5p) predicted the appearance of new distant metastases with an area under the curve of 0.79, sensitivity of 0.69 and specificity of 0.82. The serum levels of miR-8089 and miR-5698 were significantly associated with overall survival after the initiation of eribulin treatment. The present study provides evidence that serum miRNA profiling may serve as a biomarker for the responsiveness to eribulin and for predicting the development of new distant metastases in metastatic breast cancer.

miR-296-3p targets APEX1 to suppress cell migration and invasion of non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is the most common cause of cancer-associated mortality worldwide. MicroRNAs (miRs) are a class of small non-coding RNAs that are commonly dysregulated in human cancer. The aim of the current study was to evaluate the effect of miR-296-3p on the cell migration and invasion of NSCLC. Pairs of tumor tissues and para-cancerous tissues (n=50) were collected from patients with NSCLC, and the expression of miR-296-3p was analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, tumor cell viability, migration and invasion were examined in vitro using Cell Counting Kit-8, wound healing and Matrigel assays, respectively. Furthermore, potential targets of miR-296-3p were screened for using TargetScan and validated using a dual-luciferase reporter assay. The expression levels of phosphoinositide-3-kinase (PI3K), AKT serine/threonine kinase (AKT), mammalian target of rapamycin (mTOR), matrix metallopeptidase 2 (MMP2) and SRY-box 4 (SOX4) were detected by RT-qPCR and western blot analysis. The data indicated that miR-296-3p was downregulated in tumor tissues compared with adjacent normal tissues. Overexpression of miR-296-3p inhibited NSCLC cell viability, migration and invasion in vitro. Furthermore, apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1) was identified as a direct target of miR-296-3p. APEX1 expression was upregulated in tumor tissues compared with para-cancerous tissues, and the mRNA and protein expression levels of APEX1 were decreased following transfection of NSCLC cells with miR-296-3p mimics compared with control cells. Additional investigations revealed that miR-296-3p was involved in regulating the PI3K/AKT/mTOR signaling pathway, and miR-296-3p mimics decreased the mRNA and protein expression levels of MMP2 and SOX4. In summary, the findings demonstrated that miR-296-3p may function as a tumor suppressor, and inhibits the migration and invasion of NSCLC cells by targeting APEX1. miR-296-3p is therefore a potential therapeutic molecular modulator of NSCLC.

Ion Channels: New Actors Playing in Chemotherapeutic Resistance

In the battle against cancer cells, therapeutic modalities are drastically limited by intrinsic or acquired drug resistance. Resistance to therapy is not only common, but expected: if systemic agents used for cancer treatment are usually active at the beginning of therapy (i.e., 90% of primary breast cancers and 50% of metastases), about 30% of patients with early-stage breast cancer will have recurrent disease. Altered expression of ion channels is now considered as one of the hallmarks of cancer, and several ion channels have been linked to cancer cell resistance. While ion channels have been associated with cell death, apoptosis and even chemoresistance since the late 80s, the molecular mechanisms linking ion channel expression and/or function with chemotherapy have mostly emerged in the last ten years. In this review, we will highlight the relationships between ion channels and resistance to chemotherapy, with a special emphasis on the underlying molecular mechanisms.

Potential Epigenetic-Based Therapeutic Targets for Glioma

Glioma is characterized by a high recurrence rate, short survival times, high rates of mortality and treatment difficulties. Surgery, chemotherapy and radiation (RT) are the standard treatments, but outcomes rarely improve even after treatment. With the advancement of molecular pathology, recent studies have found that the development of glioma is closely related to various epigenetic phenomena, including DNA methylation, abnormal microRNA (miRNA), chromatin remodeling and histone modifications. Owing to the reversibility of epigenetic modifications, the proteins and genes that regulate these changes have become new targets in the treatment of glioma. In this review, we present a summary of the potential therapeutic targets of glioma and related effective treating drugs from the four aspects mentioned above. We further illustrate how epigenetic mechanisms dynamically regulate the pathogenesis and discuss the challenges of glioma treatment. Currently, among the epigenetic treatments, DNA methyltransferase (DNMT) inhibitors and histone deacetylase inhibitors (HDACIs) can be used for the treatment of tumors, either individually or in combination. In the treatment of glioma, only HDACIs remain a good option and they provide new directions for the treatment. Due to the complicated pathogenesis of glioma, epigenetic applications to glioma clinical treatment are still limited.

Long noncoding RNA AC003092.1 promotes temozolomide chemosensitivity through miR-195/TFPI-2 signaling modulation in glioblastoma

Temozolomide (TMZ) and radiation therapy combination for glioblastoma (GB) patients has been considered as the most effective therapy after surgical procedure. However, the overall clinical prognosis remains unsatisfactory due to intrinsic or developing resistance to TMZ. Recently, increasing evidence suggested that long noncoding RNAs (lncRNAs) play a critical role in various biological processes of tumors, and have been implicated in resistance to various drugs. However, the role of lncRNAs in TMZ resistance is poorly understood. Here, we found that the expression of lncRNA AC003092.1 was markedly decreased in TMZ resistance (TR) of GB cells (U87TR and U251TR) compared with their parental cells (U87 and U251). In patients with glioma, low levels of lncRNA AC003092.1 were correlated with increased TMZ resistance, higher risk of relapse, and poor prognosis. Overexpression of lncRNA AC003092.1 enhances TMZ sensitivity, facilitates cell apoptosis, and inhibits cell proliferation in TMZ-resistant GB cells. In addition, we identified that lncRNA AC003092.1 regulates TMZ chemosensitivity through TFPI-2-mediated cell apoptosis in vitro and in vivo. Mechanistically, further investigation revealed that lncRNA AC003092.1 regulates TFPI-2 expression through miR-195 in GB. Taken together, these data suggest that lncRNA AC003092.1 could inhibit the function of miR-195 by acting as an endogenous CeRNA, leading to increased expression of TFPI-2; this promotes TMZ-induced apoptosis, thereby making GB cells more sensitive to TMZ. Our findings indicate that overexpression of lncRNA AC003092.1 may be a potential therapy to overcome TMZ resistance in GB patients.

Glioblastoma Chemoresistance: The Double Play by Microenvironment and Blood-Brain Barrier

For glioblastoma, the tumor microenvironment (TME) is pivotal to support tumor progression and therapeutic resistance. TME consists of several types of stromal, endothelial and immune cells, which are recruited by cancer stem cells (CSCs) to influence CSC phenotype and behavior. TME also promotes the establishment of specific conditions such as hypoxia and acidosis, which play a critical role in glioblastoma chemoresistance, interfering with angiogenesis, apoptosis, DNA repair, oxidative stress, immune escape, expression and activity of multi-drug resistance (MDR)-related genes. Finally, the blood brain barrier (BBB), which insulates the brain microenvironment from the blood, is strongly linked to the drug-resistant phenotype of glioblastoma, being a major physical and physiological hurdle for the delivery of chemotherapy agents into the brain. Here, we review the features of the glioblastoma microenvironment, focusing on their involvement in the phenomenon of chemoresistance; we also summarize recent advances in generating systems to modulate or bypass the BBB for drug delivery into the brain. Genetic aspects associated with glioblastoma chemoresistance and current immune-based strategies, such as checkpoint inhibitor therapy, are described too.

MiRNA-221 from tissue may predict the prognosis of patients with osteosarcoma

This study was aimed to investigate the relationship between miR-221 expression and prognosis in patients with osteosarcoma.miR-221 expression in 69 osteosarcoma specimens and corresponding noncancer tissues were characterized by quantitative reverse transcription polymerase chain reaction. The associations of miR-221 expression with clinicopathologic factors and prognosis in patients with osteosarcoma were statistically analyzed.miR-221 expression in patients with osteosarcoma was significantly higher than in the corresponding noncancer tissues (P < .01). miR-221 overexpression was significantly associated with tumor stage, metastatic status, and response to chemotherapy pretreatment. Cox regression analysis revealed that miR-221expression, metastasis, and response to chemotherapy were independent prognostic indicators for osteosarcoma.miR-221 upregulation may predict clinical outcomes in patients with osteosarcoma.

Glioblastoma quo vadis: Will migration and invasiveness reemerge as therapeutic targets?

PURPOSE

The purpose of the current review is to highlight, on one hand, the fact that the migratory pattern of glioma cells is the major obstacle to combat them with chemotherapy, and on the other one, the new treatment strategies to overcome this obstacle.

METHODS

This review surveys several membrane and extracellular molecules involved in glioma cell migration, invasiveness and resistance to apoptosis.

RESULTS

This review focuses on signaling pathways implicated in the positive regulation of glioblastoma cell migration, including glutamate and ion channel networks, microtubes and membrane-derived extracellular vesicles (EV) containing microRNAs. Glioma cells release glutamate to the extracellular matrix, inducing neuronal cell death, which may facilitate glioma growth and invasion. Glioma cell migration and invasion are further facilitated through ion channels and transporters that modify cellular volume. Microtubes and EV promote connections and communication among glioma cells and with the microenvironment and are associated with progression and resistance to therapy. Potential therapies linked to these pathways for glioblastoma are being developed.

CONCLUSION

Our view is evolving from an intracellular view of the complex intracellular signaling pathways to one of orchestral machinery, including connections between heterogeneous tumoral and nontumoral cells and with the microenvironment through channels, microtubes, and extracellular miRNA, generating different signals at different times. All of these elements give rise to a new perspective for the treatment of glioblastoma.

Comparative transcriptome analysis to investigate the potential role of miRNAs in milk protein/fat quality

miRNAs play an important role in the processes of cell differentiation, biological development, and physiology. Here we investigated the molecular mechanisms regulating milk secretion and quality in dairy cows via transcriptome analyses of mammary gland tissues from dairy cows during the high-protein/high-fat, low-protein/low-fat or dry periods. To characterize the important roles of miRNAs and mRNAs in milk quality and to elucidate their regulatory networks in relation to milk secretion and quality, an integrated analysis was performed. A total of 25 core miRNAs were found to be differentially expressed (DE) during lactation compared to non-lactation, and these miRNAs were involved in epithelial cell terminal differentiation and mammary gland development. In addition, comprehensive analysis of mRNA and miRNA expression between high-protein/high-fat group and low-protein/low-fat groups indicated that, 38 miRNAs and 944 mRNAs were differentially expressed between them. Furthermore, 38 DE miRNAs putatively negatively regulated 253 DE mRNAs. The putative genes (253 DE mRNAs) were enriched in lipid biosynthetic process and amino acid transmembrane transporter activity. Moreover, putative DE genes were significantly enriched in fatty acid (FA) metabolism, biosynthesis of amino acids, synthesis and degradation of ketone bodies and biosynthesis of unsaturated FAs. Our results suggest that DE miRNAs might play roles as regulators of milk quality and milk secretion during mammary gland differentiation.

Novel circular RNA expression profiles reflect progression of patients with hypopharyngeal squamous cell carcinoma

Circular RNAs (circRNAs), a novel class of endogenous noncoding RNAs, have been shown to have important roles in a number of diseases, including several types of cancers. We hypothesized that circRNAs are involved in the pathogenesis of hypopharyngeal squamous cell carcinoma (HSCC). To test our hypothesis, we initially compared the expression profiles of circRNAs in 4 paired HSCC and adjacent normal tissue samples by using a circRNA microarray. The microarray data showed that 2392 circRNAs, including 1304 upregulated and 1088 downregulated circRNA transcripts, were significantly dysregulated in the HSCC tissues. The 10 most dysregulated circRNAs from the microarray analysis were further validated in another 32 pairs of specimens using quantitative real-time polymerase chain reaction assays. These circRNAs might sponge microRNAs (miRNAs) in predicted circRNA-miRNA-mRNA networks. Bioinformatics analysis was also performed to predict possible pathways in which these networks might be involved. Finally, we analyzed the interaction between validated circRNAs and their potential cancer-related miRNA targets. We are the first to comprehensively delineate the expression profiles of circRNAs in HSCC and to provide potential candidates for future mechanism studies. Our study is potentially of critical significance in uncovering the roles of circRNAs in HSCC.

miR-296-3p Negatively Regulated by Nicotine Stimulates Cytoplasmic Translocation of c-Myc via MK2 to Suppress Chemotherapy Resistance

This study aimed to identify mechanisms by which microRNA 296-3p (miR-296-3p) functions as a tumor suppressor to restrain nasopharyngeal carcinoma (NPC) cell growth, metastasis, and chemoresistance. Mechanistic studies revealed that miR-296-3p negatively regulated by nicotine directly targets the oncogenic protein mitogen-activated protein kinase-activated protein kinase-2 (Mapkapk2) (MK2). Suppression of MK2 downregulated Ras/Braf/Erk/Mek/c-Myc and phosphoinositide-3-kinase (PI3K)/Akt/c-Myc signaling and promoted cytoplasmic translocation of c-Myc, which activated miR-296-3p expression by a feedback loop. This ultimately inhibited cell cycle progression, epithelial-to-mesenchymal transition (EMT), and chemoresistance of NPC. In addition, nicotine as a key component of tobacco was observed to suppress miR-296-3p and thus elevate MK2 expression by inducing PI3K/Akt/c-Myc signaling. In clinical samples, reduced miR-296-3p as an unfavorable factor was inversely correlated with MK2 and c-Myc expression. These results reveal a novel mechanism by which miR-296-3p negatively regulated by nicotine directly targets MK2-induced Ras/Braf/Erk/Mek/c-Myc or PI3K/AKT/c-Myc signaling to stimulate its own expression and suppress NPC cell proliferation and metastasis. miR-296-3p may thus serve as a therapeutic target to reverse chemotherapy resistance of NPC.

Reactive Astrocytes in Glioblastoma Multiforme

Despite the multidisciplinary integration in the therapeutic management of glioblastoma multiforme (GBM), the prognosis of GBM patients is poor. There is growing recognition that the cells in the tumor microenvironment play a vital role in regulating the progression of glioma. Astrocytes are an important component of the blood-brain barrier (BBB) as well as the tripartite synapse neural network to promote bidirectional communication with neurons under physiological conditions. Emerging evidence shows that tumor-associated reactive astrocytes interact with glioma cells and facilitate the progression, aggression, and survival of tumors by releasing different cytokines. Communication between reactive astrocytes and glioma cells is further promoted through ion channels and ion transporters, which augment the migratory capacity and invasiveness of tumor cells by modifying H⁺ and Ca²⁺ concentrations and stimulating volume changes in the cell. This in part contributes to the loss of epithelial polarization, initiating epithelial-mesenchymal transition. Therefore, this review will summarize the recent findings on the role of reactive astrocytes in the progression of GBM and in the development of treatment-resistant glioma. In addition, the involvement of ion channels and transporters in bridging the interactions between tumor cells and astrocytes and their potential as new therapeutic anti-tumor targets will be discussed.

Kv10.1 potassium channel: from the brain to the tumors

The KCNH1 gene encodes the Kv10.1 (Eag1) ion channel, a member of the EAG (ether-à-go-go) family of voltage-gated potassium channels. Recent studies have demonstrated that KCHN1 mutations are implicated in Temple–Baraitser and Zimmermann–Laband syndromes and other forms of developmental deficits that all present with mental retardation and epilepsy, suggesting that Kv10.1 might be important for cognitive development in humans. Although the Kv10.1 channel is mainly expressed in the mammalian brain, its ectopic expression occurs in 70% of human cancers. Cancer cells and tumors expressing Kv10.1 acquire selective advantages that favor cancer progression through molecular mechanisms that involve several cellular pathways, indicating that protein–protein interactions may be important for Kv10.1 influence in cell proliferation and tumorigenesis. Several studies on transcriptional and post-transcriptional regulation of Kv10.1 expression have shown interesting mechanistic insights about Kv10.1 role in oncogenesis, increasing the importance of identifying the cellular factors that regulate Kv10.1 expression in tumors.

MicroRNA‑518b functions as a tumor suppressor in glioblastoma by targeting PDGFRB

Glioblastoma (GBM) is the most common and aggressive type of primary human brain tumor in China. Dysregulated microRNA (miRNA/miR) expression has been hypothesized to serve a role in the tumorigenesis and progression of human GBM. To explore the potential mechanisms affecting GBM tumorigenesis, the function of miR-518b in regulating GBM cell proliferation and angiogenesis was examined in vitro by CCK-8 and tube formation assay and in vivo by xenograft assay. The present study demonstrated that the expression of miR-518b was downregulated in GBM tissues and in GBM cell lines (U87 and U251). In addition, the expression levels of miR-518b were highly associated with tumor size, World Health Organization grade and prognosis. Furthermore, overexpression of miR-518b suppressed GBM cell proliferation and angiogenesis, and induced GBM cell apoptosis in vitro and in vivo. Overexpression of miR-518b also inhibited the expression of platelet-derived growth factor receptor β (PDGFRB), and the present study confirmed that the 3′ untranslated region (3′UTR) of PDGFRB was a direct target of miR-518b. In conclusion, to the best of our knowledge, the present study is the first to present evidence suggesting that miR-518b may serve as a potential marker and target in GBM treatment.

miRomics and Proteomics Reveal a miR-296-3p/PRKCA/FAK/Ras/c-Myc Feedback Loop Modulated by HDGF/DDX5/β-catenin Complex in Lung Adenocarcinoma

Purpose: This study was performed to identify the detailed mechanisms by which miR-296-3p functions as a tumor suppressor to prevent lung adenocarcinoma (LADC) cell growth, metastasis, and chemoresistance.Experimental Design: The miR-296-3p expression was examined by real-time PCR and in situ hybridization. MTT, EdU incorporation, Transwell assays, and MTT cytotoxicity were respectively performed for cell proliferation, metastasis, and chemoresistance; Western blotting was performed to analyze the pathways by miR-296-3p and HDGF/DDX5 complex. The miRNA microarray and luciferase reporter assays were respectively used for the HDGF-mediated miRNAs and target genes of miR-296-3p. The ChIP, EMSA assays, and coimmunoprecipitation combined with mass spectrometry and GST pull-down were respectively designed to analyze the DNA-protein complex and HDGF/DDX5/β-catenin complex.Results: We observed that miR-296-3p not only controls cell proliferation and metastasis, but also sensitizes LADC cells to cisplatin (DDP) in vitro and in vivo Mechanistic studies demonstrated that miR-296-3p directly targets PRKCA to suppress FAK-Ras-c-Myc signaling, thus stimulating its own expression in a feedback loop that blocks cell cycle and epithelial-mesenchymal transition (EMT) signal. Furthermore, we observed that suppression of HDGF-β-catenin-c-Myc signaling activates miR-296-3p, ultimately inhibiting the PRKCA-FAK-Ras pathway. Finally, we found that DDX5 directly interacts with HDGF and induces β-catenin-c-Myc, which suppresses miR-296-3p and further activates PRKCA-FAK-Ras, cell cycle, and EMT signaling. In clinical samples, reduced miR-296-3p is an unfavorable factor that inversely correlates with HDGF/DDX5, but not PRKCA.Conclusions: Our study provides a novel mechanism that the miR-296-3p-PRKCA-FAK-Ras-c-Myc feedback loop modulated by HDGF/DDX5/β-catenin complex attenuates cell growth, metastasis, and chemoresistance in LADC. Clin Cancer Res; 23(20); 6336-50. ©2017 AACR.

Integrative microRNA and gene profiling data analysis reveals novel biomarkers and mechanisms for lung cancer

BACKGROUND

Studies on the accuracy of microRNAs (miRNAs) in diagnosing non-small cell lung cancer (NSCLC) have still controversial. Therefore, we conduct to systematically identify miRNAs related to NSCLC, and their target genes expression changes using microarray data sets.

METHODS

We screened out five miRNAs and six genes microarray data sets that contained miRNAs and genes expression in NSCLC from Gene Expression Omnibus.

RESULTS

Our analysis results indicated that fourteen miRNAs were significantly dysregulated in NSCLC. Five of them were up-regulated (miR-9, miR-708, miR-296-3p, miR-892b, miR-140-5P) while nine were down-regulated (miR-584, miR-218, miR-30b, miR-522, miR486-5P, miR-34c-3p, miR-34b, miR-516b, miR-592). The integrating diagnosis sensitivity (SE) and specificity (SP) were 82.6% and 89.9%, respectively. We also found that 4 target genes (p < 0.05, fold change > 2.0) were significant correlation with the 14 discovered miRNAs, and the classifiers we built from one training set predicted the validation set with higher accuracy (SE = 0.987, SP = 0.824).

CONCLUSIONS

Our results demonstrate that integrating miRNAs and target genes are valuable for identifying promising biomarkers, and provided a new insight on underlying mechanism of NSCLC. Further, our well-designed validation studies surely warrant the investigation of the role of target genes related to these 14 miRNAs in the prediction and development of NSCLC.

Potential mechanisms of microRNA-129-5p in inhibiting cell processes including viability, proliferation, migration and invasiveness of glioblastoma cells U87 through targeting FNDC3B

The purpose of our study is to clarify the effects of microRNA-129-5p (miR-129-5p) in cellular processes correlated with cancer development and progression of Glioblastoma (GBM) cell by regulating FNDC3B. MiR-129-5p and FNDC3B expression in GBM tissues and tumor adjacent tissues were tested by quantitative real-time PCR. We validated the target relationship between miR-129-5p and FNDC3B by dual luciferase reporter gene system. MTT, colony formation, flow cytometry, Transwell and wound healing assays were used to analyze cell viability, proliferation, apoptosis, invasiveness and migration. The level of FNDC3B protein expression was detected by Western Blot. MiR-129-5p was downregulated in GBM tissues and cell lines, while FNDC3B was upregulated in GBM tissues. The result of luciferase reporter gene assay demonstrated that miR-129-5p could target FNDC3B by binding to the 3' UTR. The overexpression of miR-129-5p or the inhibition of FNDC3B can both inhibit U87 cell viability, proliferation, migration and invasion, while promote cell apoptosis. Our results suggested that miR-129-5p could directly suppress FNDC3B, which might be one of potential mechanisms in inhibiting cell processes including viability, proliferation, migration and invasiveness of U87 cells.