MicroRNA-7 inhibits cell proliferation, migration and invasion in human non-small cell lung cancer cells by targeting FAK through ERK/MAPK signaling pathway

Prospects of focal adhesion kinase inhibitors as a cancer therapy in preclinical and early phase study

INTRODUCTION

FAK, a nonreceptor cytoplasmic tyrosine kinase, plays a crucial role in tumor metastasis, drug resistance, tumor stem cell maintenance, and regulation of the tumor microenvironment. FAK has emerged as a promising target for tumor therapy based on both preclinical and clinical data.

AREAS COVERED

This paper aims to summarize the molecular mechanisms underlying FAK's involvement in tumorigenesis and progression. Encouraging results have emerged from ongoing clinical trials of FAK inhibitors. Additionally, we present an overview of clinical trials for FAK inhibitors, examining their potential as promising treatments. The pertinent studies gathered from databases including PubMed, ClinicalTrials.gov.

EXPERT OPINION

Since the first finding in 1990s, targeting FAK has became the focus of interests in many pharmaceutical companies. Through 30 years' discovery, the industry and academy gradually realized the features of FAK target which may not be a driver gene but a solid defense system for the cancer initiation and development. Currently, the ongoing clinical regimens involving FAK inhibition are all the combination strategies in which FAK inhibitors can further strengthen the cancer cell killing effects of other testing agents. The emerging positive signal in clinical trials foresee targeting FAK as class will be an effective mean to fight against cancers.

Non-coding RNAs as potential therapeutic targets for receptor tyrosine kinase signaling in solid tumors: current status and future directions

This review article presents an in-depth analysis of the current state of research on receptor tyrosine kinase regulatory non-coding RNAs (RTK-RNAs) in solid tumors. RTK-RNAs belong to a class of non-coding RNAs (nc-RNAs) responsible for regulating the expression and activity of receptor tyrosine kinases (RTKs), which play a critical role in cancer development and progression. The article explores the molecular mechanisms through which RTK-RNAs modulate RTK signaling pathways and highlights recent advancements in the field. This include the identification of potential new RTK-RNAs and development of therapeutic strategies targeting RTK-RNAs. While the review discusses promising results from a variety of studies, encompassing in vitro, in vivo, and clinical investigations, it is important to acknowledge the challenges and limitations associated with targeting RTK-RNAs for therapeutic applications. Further studies involving various cancer cell lines, animal models, and ultimately, patients are necessary to validate the efficacy of targeting RTK-RNAs. The specificity of ncRNAs in targeting cellular pathways grants them tremendous potential, but careful consideration is required to minimize off-target effects, the article additionally discusses the potential clinical applications of RTK-RNAs as biomarkers for cancer diagnosis, prognosis, and treatment. In essence, by providing a comprehensive overview of the current understanding of RTK-RNAs in solid tumors, this review emphasizes their potential as therapeutic targets for cancer while acknowledging the associated challenges and limitations.

Prospects of microRNAs as therapeutic biomarkers in non-small cell lung cancer

Lung Cancer, the second most common cancer worldwide, remains the leading cause of cancer-related deaths, contemporarily. More than 85% of identified lung cancer cases are comprised of non-small-cell lung carcinoma (NSCLC). Despite the best advancements in the realm of NSCLC therapy, the five-year survival period of NSCLC patients remains unchanged. Underlying complex molecular heterogeneity, delay in early detection resulting in progression of the disease to its advanced stage and acquired resistance of NSCLC cells during therapy have posed additional challenges for circumventing the discrepancies in treatment strategy. microRNAs (miRNAs) are a class of non-coding RNAs, identified as molecules playing an indispensable role in tumorigenesis & progression and metastasis of several cancers, including NSCLC, either by possessing tumor suppressor or by oncogenic functions. As observed across several studies, miRNA dysregulation has been recognised as a causative mechanism behind NSCLC tumorigenesis. In this review, we discuss the role of miRNAs in NSCLC tumor progression caused by their dysregulation, thereby stating their potential therapeutic application in NSCLC as therapeutic biomarkers. We have also highlighted the recent findings of some of the most widely studied tumor suppressor (miR-486, miR-7 miR-34), and oncogene miRNAs (miR-21, miR-224, miR-135b) that can be further explored for its therapeutic potentialities in the management of NSCLC.

miR-124 as a Liquid Biopsy Prognostic Biomarker in Small Extracellular Vesicles from NSCLC Patients

Despite advances in non-small cell lung cancer (NSCLC) research, this is still the most common cancer type that has been diagnosed up to date. microRNAs have emerged as useful clinical biomarkers in both tissue and liquid biopsy. However, there are no reliable predictive biomarkers for clinical use. We evaluated the preclinical use of seven candidate miRNAs previously identified by our group. We collected a total of 120 prospective samples from 88 NSCLC patients. miRNA levels were analyzed via qRT-PCR from tissue and blood samples. miR-124 gene target prediction was performed using RNA sequencing data from our group and interrogating data from 2952 NSCLC patients from two public databases. We found higher levels of all seven miRNAs in tissue compared to plasma samples, except for miR-124. Our findings indicate that levels of miR-124, both free-circulating and within exosomes, are increased throughout the progression of the disease, suggesting its potential as a marker of disease progression in both advanced and early stages. Our bioinformatics approach identified KPNA4 and SPOCK1 as potential miR-124 targets in NSCLC. miR-124 levels can be used to identify early-stage NSCLC patients at higher risk of relapse.

EIF4A3-induced circular RNA SCAP facilitates tumorigenesis and progression of non-small-cell lung cancer via miR-7/SMAD2 signaling

The eukaryotic translation initiation factor 4A (eIF4A) family determines transcription efficiency by directly binding to precursor RNAs. One member, EIF4A3, modulates the expression of circRNAs. Circular RNA SCAP (circSCAP), a newly found circRNA, has been implicated in atherosclerosis. Yet, how circSCAP regulates cancer development and progression remains understudied. Here, we investigated the function of circSCAP and the molecular mechanism in the tumorigenesis and progression of non-small-cell lung cancer (NSCLC). CircSCAP was upregulated in both NSCLC tissues and cell lines and was mainly located in the cytoplasm. CircSCAP expression was promoted by EIF4A3, which was associated with poor prognosis in patients with NSCLC. CircSCAP sponged miR-7 to upregulate small mothers against decapentaplegic 2 (SMAD2). CircSCAP knockdown undermined cell proliferation, migration, and invasion abilities in NSCLC cell lines (SPCA1 and A549), which was rescued by either inhibiting miR-7 or overexpressing SMAD2. Moreover, circSCAP knockdown upregulated E-cadherin, while downregulating N-cadherin, Vimentin, and MMP9 in SPCA1 and A549 cells, which were abolished by either inhibiting miR-7 or overexpressing SMAD2. Additionally, miR-7 was markedly downregulated, whereas SMAD2 was significantly upregulated in NSCLC tissues. MiR-7 expression was inversely correlated with circSCAP and SMAD2 expression in NSCLC tissues. In conclusion, this study demonstrates that circSCAP is significantly upregulated in NSCLC cell lines and tissues and elucidates that circSCAP facilitates NSCLC progression by sponging miR-7 and upregulating SMAD2. The study provides a novel molecular target for early diagnosis and treatment of NSCLC.

Optimized thyroid transcription factor-1 core promoter-driven microRNA-7 expression effectively inhibits the growth of human non-small-cell lung cancer cells

Targeted gene therapy has become a promising approach for lung cancer treatment. In our previous work, we reported that the targeted expression of microRNA-7 (miR-7) operated by thyroid transcription factor-1 (TTF-1) promoter inhibited the growth of human lung cancer cells in vitro and in vivo; however, the intervention efficiency needed to be further improved. In this study, we identified the core promoter of TTF-1 (from -1299 bp to -871 bp) by 5' deletion assay and screened out the putative transcription factors nuclear factor-1 (NF-1) and activator protein-1 (AP-1). Further analysis revealed that the expression level of NF-1, but not AP-1, was positively connected with the activation of TTF-1 core promoter in human non-small-cell lung cancer (NSCLC) cells. Moreover, the silencing of NF-1 could reduce the expression level of miR-7 operated by TTF-1 core promoter. Of note, we optimized four distinct sequences to form additional NF-1-binding sites (TGGCA) in the sequence of TTF-1 core promoter (termed as ^optTTF-1 promoter), and verified the binding efficiency of NF-1 on the ^optTTF-1 promoter by electrophoretic mobility shift assay (EMSA). As expected, the ^optTTF-1 promoter could more effectively drive miR-7 expression and inhibit the growth of human NSCLC cells in vitro, accompanied by a reduced transduction of NADH dehydrogenase (ubiquinone) 1α subcomplex 4 (NDUFA4)/protein kinase B (Akt) pathway. Consistently, ^optTTF-1 promoter-driven miR-7 expression could also effectively abrogate the growth and metastasis of tumor cells in a murine xenograft model of human NSCLC. Finally, no significant changes were detected in the biological indicators or the histology of some important tissues and organs, including heart, liver, and spleen. On the whole, our study revealed that the optimized TTF-1 promoter could more effectively operate miR-7 to influence the growth of human NSCLC cells, providing a new basis for the development of microRNA-based targeting gene therapy against clinical lung cancer.

Role of MicroRNA-7 (MiR-7) in Cancer Physiopathology

miRNAs are non-coding RNA sequences of approximately 22 nucleotides that interact with genes by inhibiting their translation through binding to their 3′ or 5′ UTR regions. Following their discovery, the role they play in the development of various pathologies, particularly cancer, has been studied. In this context, miR-7 is described as an important factor in the development of cancer because of its role as a tumor suppressor, regulating a large number of genes involved in the development and progression of cancer. Recent data support the function of miR-7 as a prognostic biomarker in cancer, and miR-7 has been proposed as a strategy in cancer therapy. In this work, the role of miR-7 in various types of cancer is reviewed, illustrating its regulation, direct targets, and effects, as well as its possible relationship to the clinical outcome of cancer patients.

Chromobox Homologue 7 Acts as a Tumor Suppressor in Both Lung Adenocarcinoma and Lung Squamous Cell Carcinoma via Inhibiting ERK/MAPK Signaling Pathway

Chromobox homologue 7 (CBX7) is a member of the polycomb group family that plays a pivotal role in regulating cellular processes in human cancers. This study aims to explore the function and underlying molecular mechanisms of CBX7 in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). The expression of CBX7 in LUAD and LUSC tissues was analyzed by UALCAN and GEPIA based on the TCGA database. Cell viability and apoptosis were measured by CCK-8 and flow cytometry assays, respectively. Cell migration and invasion were detected by transwell assay. The functions of downregulated genes in LUAD were enriched via GO and KEGG pathway analyses. The mRNA expression of CBX7, ERK1/2, and p38 was determined by qRT-PCR, and the protein levels of CBX7, ERK1/2, p-ERK1/2, p38, and p-p38 were measured by Western blotting. Tumor xenograft model was established to validate the antitumor effect of CBX7. The expression of CBX7 and Ki-67 in tumor tissues was detected by immunohistochemistry. CBX7 was downregulated in the tissues and cells of both LUAD and LUSC. Low CBX7 expression was associated with a poor overall survival rate in LUAD patients. CBX7 overexpression inhibited the viability, migration, and invasion and promoted the apoptosis of LUAD and LUSC cells. In addition, the downregulated genes in LUAD were enriched in MAPK cascade (GO) and MAPK signaling pathway (KEGG). ERK/MAPK pathway was then determined as a downstream target of CBX7, which was inhibited by CBX7 overexpression in LUAD and LUSC cells. The overexpression of CBX7 inhibited the malignant progression of LUAD and LUSC cells probably via suppressing the ERK/MAPK signaling pathway in vitro and in vivo.

The molecular mechanism of baicalein repressing progression of gastric cancer mediating miR-7/FAK/AKT signaling pathway

BACKGROUND

Baicalein (BAI) has a significant anti-cancerous function in the treatment of gastric cancer (GC). Focal adhesion kinase (FAK) is a key regulatory molecule in integrin and growth factor receptor mediated signaling. MicroRNA-7 (miR-7), has been considered as a potential tumor suppressor in a variety of cancers. However, the possible mechanisms by which BAI inhibiting progression of gastric cancer mediating miR-7/FAK/AKT signaling pathway remain unclear.

PURPOSE

To investigate the molecular mechanism and effects of BAI inhibiting progression of gastric cancer mediating miR-7/FAK/AKT signaling pathway.

METHODS

Gastric cancer cell lines with FAK knockdown and overexpression were constructed by lentivirus transfection. After BAI treatment, the effects of FAK protein on proliferation, metastasis and angiogenesis of gastric cancer cells were detected by MTT, EdU, colony formation, wound healing, transwell and Matrigel tube formation assays. In vivo experiment was performed by xenograft model. Immunofluorescence and western blot assay were used to detect the effects of FAK protein on the expression levels of EMT markers and PI3K/AKT signaling pathway related proteins. qRT-PCR and luciferase reporter assay were used to clarify the targeting relationship between miR-7 and FAK.

RESULTS

BAI can regulate FAK to affect proliferation, metastasis and angiogenesis of gastric cancer cells through PI3K/AKT signaling pathway. qRT-PCR showed BAI can upregulated the expression of miR-7 and luciferase reporter assay showed the targeting relationship between miR-7 and FAK. Additionally, miR-7 mediates cell proliferation, metastasis and angiogenesis by directly targeting FAK 3'UTR to inhibit FAK expression.

CONCLUSION

BAI repressing progression of gastric cancer mediating miR-7/FAK/AKT signaling pathway.

Cell Behavior of Non-Small Cell Lung Cancer Is at EGFR and MicroRNAs Hands

Lung cancer is a complex disease associated with gene mutations, particularly mutations of Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) and epidermal growth factor receptor (EGFR). Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the two major types of lung cancer. The former includes most lung cancers (85%) and are commonly associated with EGFR mutations. Several EGFR-tyrosine kinase inhibitors (EGFR-TKIs), including erlotinib, gefitinib, and osimertinib, are effective therapeutic agents in EGFR-mutated NSCLC. However, their effectiveness is limited by the development (acquired) or presence of intrinsic drug resistance. MicroRNAs (miRNAs) are key gene regulators that play a profound role in the development and outcomes for NSCLC via their role as oncogenes or oncosuppressors. The regulatory role of miRNA-dependent EGFR crosstalk depends on EGFR signaling pathway, including Rat Sarcoma/Rapidly Accelerated Fibrosarcoma/Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase 1/2 (Ras/Raf/MEK/ERK1/2), Signal Transducer and Activator of Transcription (STAT), Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NF-kB), phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), Janus kinase 1 (JAK1), and growth factor receptor-bound protein 2 (GRB2). Dysregulated expression of miRNAs affects sensitivity to treatment with EGFR-TKIs. Thus, abnormalities in miRNA-dependent EGFR crosstalk can be used as diagnostic and prognostic markers, as well as therapeutic targets in NSCLC. In this review, we present an overview of miRNA-dependent EGFR expression regulation, which modulates the behavior and progression of NSCLC.

FAK-targeting PROTAC demonstrates enhanced antitumor activity against KRAS mutant non-small cell lung cancer

Focal adhesion kinase (FAK) has been established as a promising therapeutic target for KRAS mutant non-small cell lung cancer (NSCLC). However, phase II clinical trials of a FAK inhibitor (Defactinib) have only shown modest antitumor activity. To address this challenge, here we report the use of a FAK-targeting proteolysis targeting chimera (D-PROTAC) to treat KRAS mutant NSCLC. We validated that D-PROTAC could efficiently eliminate FAK protein via the ubiquitin-proteasome pathway in KRAS mutant NSCLC A427 cells, causing over 90% degradation at 800 nM. After comparing both in vitro and in vivo therapeutic efficacies, we demonstrated that D-PRTOAC outperformed Defactinib in inhibiting tumor growth. Specifically, D-PROTAC at 800 nM reduced cell viability, migration, and invasion by ∼80%. Furthermore, a ∼85% suppression of tumor growth was elicited by D-PROTAC when intratumorally administrated at 10 mg/kg in subcutaneous A427-bearing mice. These results thus demonstrate for the first time that PROTACs may serve as promising therapeutic agents for the intractable NSCLC harboring KRAS mutations.

miR-491-5p inhibits the proliferation and migration of A549 cells by FOXP4

Aberrant expression of microRNAs (miRNAs/miRs) plays a key role in the development of non-small cell lung cancer (NSCLC). In the present study, lower miRNA (miR)-491-5p levels and a higher forkhead box P4 (FOXP4) mRNA level were observed in NSCLC tissues and cell lines, compared to adjacent tissues and the normal human lung epithelial cell line BEAS-2B, respectively. A549 cell proliferation and migration were inhibited upon transfection of miR-491-5p mimics compared to miR-negative control (NC) mimics. In addition, compared to miR-NC mimics, overexpression of miR-491-5p decreased FOXP4 expression, while downregulation of miR-491-5p increased FOXP4 expression in A549 cells. The dual luciferase assay confirmed that the 3'untranslated region of FOXP4 was a target for miR-491-5p in A549 cells. Moreover, compared with the control short hairpin (sh)RNA, there was lower expression levels of TGF-β and its downstream targets (MMP-2 and MMP-9) in the FOXP4 shRNA group. Similarly, compared to miR-NC mimics, overexpression of miR-491-5p decreased MMP-2 and MMP-9 expression levels. In FOXP4-knockdown A549 cells, overexpression of miR-491-5p showed little effect on cell proliferation/migration. In A549 cells, overexpression of FOXP4 partially reversed the miR-491-5p mimics-induced inhibition on the cell proliferation and migration. These results may provide new insights into the role of miR-491-5p in NSCLC.

MiR-7 in Cancer Development

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

Uncovering the Anti-Lung-Cancer Mechanisms of the Herbal Drug FDY2004 by Network Pharmacology

With growing evidence on the therapeutic efficacy and safety of herbal drugs, there has been a substantial increase in their application in the lung cancer treatment. Meanwhile, their action mechanisms at the system level have not been comprehensively uncovered. To this end, we employed a network pharmacology methodology to elucidate the systematic action mechanisms of FDY2004, an anticancer herbal drug composed of Moutan Radicis Cortex, Persicae Semen, and Rhei Radix et Rhizoma, in lung cancer treatment. By evaluating the pharmacokinetic properties of the chemical compounds present in FDY2004 using herbal medicine-associated databases, we identified its 29 active chemical components interacting with 141 lung cancer-associated therapeutic targets in humans. The functional enrichment analysis of the lung cancer-related targets of FDY2004 revealed the enriched Gene Ontology terms, involving the regulation of cell proliferation and growth, cell survival and death, and oxidative stress responses. Moreover, we identified key FDY2004-targeted oncogenic and tumor-suppressive pathways associated with lung cancer, including the phosphatidylinositol 3-kinase-Akt, mitogen-activated protein kinase, tumor necrosis factor, Ras, focal adhesion, and hypoxia-inducible factor-1 signaling pathways. Overall, our study provides novel evidence and basis for research on the comprehensive anticancer mechanisms of herbal medicines in lung cancer treatment.

Exosomes-transmitted miR-7 reverses gefitinib resistance by targeting YAP in non-small-cell lung cancer

Epidermal growth factor receptor (EGFR) T790M mutation act as the dominant resistance mechanism to first and second generations tyrosine kinase inhibitors (TKIs), the roles of miR-7 in the development of T790M mutation are largely unknown. Here, we confirmed that the level of miR-7 was significantly higher in the gefitinib sensitivity PC9 cells compared to gefitinib resistance H1975 cells, and miR-7 overexpression promoted the apoptosis of H1975 cells by gefitinib treatment. Furthermore, we found that exosomes could transfer miR-7 mimics from PC9 cells to H1975 cells, which reversed gefitinib resistance through binding to YAP, and altered H1975 cells resistance phenotype in vitro. In addition, we suppressed exosomal miR-7 by GW4869, increasing PC9 cells chemoresistance to gefitinib treatment in vivo. Of note, we detected that miR-7 was significantly higher in serum exosomes from healthy controls than from patients with lung carcinoma, and high miR-7 expression was associated with strong response to lung carcinoma patients receiving gefitinib treatment, as well as a longer survival. Therefore, exosomal miR-7 can act as a potential biomarker and therapeutic target for EGFR T79M resistance mutations.

Circular RNA 0001313 Knockdown Suppresses Non-Small Cell Lung Cancer Cell Proliferation and Invasion via the microRNA-452/HMGB3/ERK/MAPK Axis

Background

Non-small cell lung cancer (NSCLC) seriously endangers human health. Circular RNAs (circRNAs) regulate diverse types of cancers, including NSCLC. This study investigated the possible mechanism of circ0001313 in NSCLC.

Materials and Methods

Circ0001313 expression in NSCLC tissues was measured, and its correlation with clinicopathological features was analyzed. The binding relationships among circ0001313, microRNA (miR)-452 and HMGB3 were tested. The gain and loss of functions were performed to examine NSCLC cell malignant behaviors. After HMGB3 overexpression, ERK/MAPK pathway-related protein levels were detected. Subsequently, the rescue experiment was further performed using an ERK/MAPK pathway inhibitor PD98059.

Results

Abnormally elevated circ0001313 and decreased miR-452 in NSCLC cells were observed. Circ0001313 silencing or miR-452 overexpression significantly reduced NSCLC cell proliferation and invasion. Circ0001313 competitively bound to miR-452 to upregulate HMGB3, thus promoting NSCLC cell growth. HMGB3 overexpression activated the ERK/MAPK pathway to contribute to NSCLC development.

Conclusion

We highlighted that silencing of circ0001313 blunted the ERK/MAPK pathway via the miR-452/HMGB3 axis, thereby inhibiting NSCLC cell proliferation and invasion.

MicroRNAs as regulators of ERK/MAPK pathway: A comprehensive review

The ERK/MAPK cascade is one the four distinctive MAPK cascades which transmit extracellular signals to intracellular targets. This cascade has an important role in the regulation of several fundamental processes such as proliferation, differentiation and cell response to diverse extrinsic stresses. Moreover, several studies have shown participation of this cascade in the pathogenesis of cancer. Recent investigations have unraveled interaction between microRNAs (miRNAs) and ERK/MAPK cascade. These transcripts reside in both upstream and downstream of this cascade, regulating or being regulated by ERK/MAPK proteins. In the current review, we summarize the role of miRNAs in the regulation of ERK/MAPK and their contribution in the pathogenesis of human disorders with particular focus on cancers.

Down-Regulation of miR-7 in Gastric Cancer Is Associated With Elevated LDH-A Expression and Chemoresistance to Cisplatin

MicroRNAs (miRNAs) are dysregulated in the context of many cancer types, making them potentially ideal diagnostic or therapeutic targets in patients in which they are aberrantly expressed. In the present study, we found miR-7 to be downregulated in gastric cancer (GC), and we further determined its expression to be closely linked to GC sensitivity to the chemotherapeutic compound cisplatin. This effect appears to be at least partially attributable to the regulation of LDH-A, which is a miR-7 target gene and expression of LDH-A is negatively correlated with miR-7 expression in primary GC tumor samples. When upregulated, we also determined that miR-7 was able to inhibit the proliferation, colony formation, and glycolysis of GC cells owing to its regulation of LDH-A. Moreover, overexpression of miR-7 render cells more sensitive to cisplatin. Our results thus provide novel evidence that miR-7 is a key mediator of GC growth and chemosensitivity through its regulation of LDH-A, thus potentially highlighting this pathway as a therapeutic target for treating affected patients.

The N-terminal polypeptide derived from vMIP-II exerts its antitumor activity in human breast cancer through CXCR4/miR-7-5p/Skp2 pathway

Breast cancer is a malignant tumor with the highest incidence in women of the world. CXCR4 and Skp2 are highly expressed in breast cancer cells and CXCR4 was positively correlated with Skp2 by interference or overexpression. The microRNA array was used to detect the differentially expressed spectrum of micro RNAs in breast cancer cells the changes of miR-7-5p after CXCR4 inhibitor (NT21MP) treatment to block the CXCR4/SDF-1 pathway was founded. MiR-7-5p has been found to be correlated with Skp2 in various tumors in the literature, and Skp2 expression can be regulated by transfection with miR-7-5p mimics or inhibitors. The expression level of miR-7-5p was upregulated or downregulated after CXCR4 interference or overexpression. Combined with the correlation between CXCR4 and miR-7-5p in the chip results, CXCR4 may regulate Skp2 through miR-7-5p. Epithelial cells have the morphological characteristics of mesenchymal cells for some reason called epithelial-mesenchymal transformation (EMT). Transfection of miR-7-5p mimics into drug-resistant cells reduced Skp2 levels, decreased the expression of Vimentin, Snail, and slug, and increased the expression of E-cadherin. CXCR4 inhibitor (NT21MP) can reverse the EMT changes caused by miR-7-5p inhibitor. Similarly, in vivo results suggesting that CXCR4 inhibitors can reverse the EMT phenotype of drug-resistant breast cancer cells through the CXCR4/miR-7-5p/Skp2 pathway. In summary, the CXCR4/miR-7-5p/Skp2 signaling pathway plays an important role in the progression of breast cancer. This study provides a theoretical basis for the treatment of breast cancer by targeting the CXCR4 pathway.

CDR1as/miRNAs-related regulatory mechanisms in muscle development and diseases

Muscles are critical tissues for mammals due to their close association with movement and physiology. Myogenesis involves proliferation, differentiation, and fusion of myoblast, in which many well-known protein-coding genes, as well as linear non-coding RNAs such as microRNAs (miRNAs), are involved. Recently, circular RNAs (circRNAs) have attracted much attention since several circRNAs are known to play significant roles in muscle development and diseases through limited mechanisms, particularly through sponging miRNAs. Through advanced researches, increasing evidence suggests that Cerebellar Degeneration-Related protein 1 antisense (CDR1as) is an important circRNA that regulates the levels of mRNAs expression via competitively sponged miRNAs. Here, we reviewed the robust expression and base pairing relationships of CDR1as and several myogenic miRNAs, as well as these miRNAs and their targeted genes in muscles or some muscle-related diseases. These potential CDR1as/miRNAs/mRNA pathways will provide the basis for further research on the function of CDR1as in muscle development, and eventually extend the versatile roles of CDR1as in mammals.

Golgi reassembly and stacking protein 65 downregulation is required for the anti-cancer effect of dihydromyricetin on human ovarian cancer cells

Golgi reassembly and stacking protein 65 (GRASP65), which has been involved in cancer progression, is associated with tumor growth and cell apoptosis. Dihydromyricetin (DHM) has demonstrated antitumor activity in different types of human cancers. However, the pharmacological effects of DHM on ovarian cancer (OC) and the molecular mechanisms that underlie these effects are largely unknown. The present study showed that DHM reduced cell migration and invasion in a concentration- and time-dependent manner and induced cell apoptosis primarily through upregulation of Cleaved-caspase-3 and the Bax/Bcl-2 ratio in OCs. To further clarify the cancer therapeutic target, we assessed the effect of DHM on the expression of GRASP65, which is overexpressed in human ovarian cancer tissues. DHM activated caspase-3 and decreased GRASP65 expression to promote cell apoptosis, implying that downregulation of GRASP65 was related to DHM-induced cell apoptosis. Additionally, the knockdown of GRASP65 by siRNA resulted in increased apoptosis after DHM treatment, while western blot and flow cytometry analysis demonstrated that overexpression of GRASP65 attenuated DHM-mediated apoptosis. In addition, the JNK/ERK pathway may be involved in DHM-mediated caspase-3 activation and GRASP65 downregulation. Taken together, these findings provide novel evidence of the anti-cancer properties of DHM in OCs, indicating that DHM is a potential therapeutic agent for ovarian cancer through the inhibition of GRASP65 expression and the regulation of JNK/ERK pathway.

Hypermethylation of Anti-oncogenic MicroRNA 7 is Increased in Emphysema Patients

INTRODUCTION

MicroRNA-7 (miR-7) has a suppressive role in lung cancer and alterations in its DNA methylation may contribute to tumorigenesis. As COPD patients with emphysema have a higher risk of lung cancer than other COPD phenotypes, we compared the miR-7 methylation status among smoker subjects and patients with various COPD phenotypes to identify its main determinants.

METHODS

30 smoker subjects without airflow limitation and 136 COPD patients without evidence of cancer were recruited in a prospective study. Clinical and functional characteristics were assessed and patients were classified into: frequent exacerbator, emphysema, chronic bronchitis and asthma COPD overlap (ACO). DNA collected from buccal epithelial samples was isolated and bisulfite modified. miR-7 methylation status was evaluated by quantitative methylation-specific polymerase chain reaction (qMSP).

RESULTS

miR-7 Methylated levels were higher in COPD patients than in smokers without airflow limitation (23.7±12.4 vs. 18.5±8.8%, p=0.018). Among COPD patients, those with emphysema had higher values of methylated miR-7 (27.1±10.2%) than those with exacerbator (19.4±9.9%, p=0.004), chronic bronchitis (17.3±9.0%, p=0.002) or ACO phenotypes (16.0±7.2%, p=0.010). After adjusting for clinical parameters, differences between emphysematous patients and those with other phenotypes were retained. In COPD patients, advanced age, mild-moderate airflow limitation, reduced diffusing capacity and increased functional residual capacity were identified as independent predictors of methylated miR-7 levels.

CONCLUSION

The increase of miR-7 methylation levels experienced by COPD patients occurs mainly at the expense of the emphysema phenotype, which might contribute to explain the higher incidence of lung cancer in these patients.

Triple negative breast cancer: microRNA expression profile and novel discriminators according to BRCA1 status

Triple-negative breast cancer (TNBC) represents 15% of breast carcinomas. More than 80% of women with a breast cancer associated with a breast cancer type 1 (BRCA1) mutation develop a TNBC. microRNAs (miRNAs) play critical roles in diverse biological processes and are aberrantly expressed in several human neoplasms including breast cancer, where they function as actors of tumor onset, behavior, and progression. However, an extensive microRNA profile has not yet been determined for TNBC. Taqman low-density arrays (TLDAs) were used to screen the expression level of 667 miRNAs in TNBC versus normal breast tissues. Our TLDA results revealed 20 differentially expressed miRNAs among which 14 (10 upregulated and four downregulated) were confirmed by an individual quantitative real-time polymerase chain reaction. Interestingly, a novel link between BRCA1 status and miRNA expression level was identified through miR-96 and miR-10b that were very important discriminators between TNBC with mutated BRCA1 and TNBC with wild type BRCA1. This study promises discoveries of new pathological pathways at work in this dreadful disease and clearly warrants validation in large prospective studies with the aim of identifying novel biomarkers for diagnosis and targets for clinical interventions.

Runt-related transcription factor 1 contributes to lung cancer development by binding to tartrate-resistant acid phosphatase 5

Lung cancer (LC) is one of the malignant tumors with growing morbidity and mortality. The involvement of runt-related transcription factor 1 (RUNX1) in LC patients has been elucidated. We intended to research mechanisms of RUNX1 and tartrate-resistant acid phosphatase 5 (ACP5) in LC. Firstly, ACP5 levels in LC tissues, paracancerous tissues, LC cells and tracheal epithelial cells were detected. RUNX1 overexpression plasmid and interference plasmid were constructed and transfected into 95C cells and A549 cells, respectively. The binding of RUNX1 to ACP5 promoter was tested. Additionally, the gain- and loss-of-function were performed to explore the effects of ACP5 and RUNX1 on LC biological process. The xenograft tumor in nude mice was constructed in vivo to verify in vitro results. Functional rescue experiment was performed by adding MAPK-specific activator P79350 to A549 cells with si-ACP5 to measure the effects of ERK/MAPK axis on LC progression. Consequently, we found ACP5 expression was higher in LC tissues and cells, and ACP5 silencing suppressed LC cell growth. Overexpression of ACP5 promoted malignant biological behavior of LC cells. RUNX1 could bind to ACP5 promoter, and overexpressed RUNX1 promoted ACP5 expression and LC cell growth. Moreover, ACP5 upregulated the ERK/MAPK axis and thus promoted LC progression. The results of xenograft tumor in nude mice showed that silencing ACP5 could inhibit the growth of LC cells in vivo. To conclude, silenced RUNX1 inhibits LC progression through the ERK/MAPK axis by binding to ACP5. This study may provide new approaches for LC treatment.

circRNA CDR1as Regulated the Proliferation of Human Periodontal Ligament Stem Cells under a Lipopolysaccharide-Induced Inflammatory Condition

circRNA CDR1as (CDR1as) has been demonstrated to play important roles in a variety of inflammation-related diseases by acting as miRNA sponges. The present study is aimed at investigating the potential roles of CDR1as in the proliferation of human periodontal ligament stem cells (PDLSCs) under an inflammatory condition induced by Porphyromonas gingivalis-derived lipopolysaccharide (LPS). Human periodontal ligament cells (PDLCs) were isolated from periodontal ligament tissue, and PDLSCs were sorted from PDLCs based on the STRO-1 expression through fluorescence-activated cell sorting. We further found that CDR1as was significantly downregulated in LPS-treated PDLSCs compared to untreated cells, as well as in normal periodontal ligament tissues compared to periodontitis tissues. Knockdown of CDR1as promoted LPS-induced proliferative inhibition of PDLSCs, whereas overexpression of CDR1as alleviated the LPS-induced proliferative ability of PDLSCs. Mechanistically, CDR1as functioned as an miR-7 sponge to activate the ERK signal pathway to mediate the inhibition effect of LPS on cell proliferation. Taken together, our findings revealed the effects of the interacting pair of CDR1as/miR-7 on the proliferation ability of PDLSCs within their surrounding inflammatory microenvironment of periodontitis.

MicroRNA‑208a directly targets Src kinase signaling inhibitor 1 to facilitate cell proliferation and invasion in non‑small cell lung cancer

The abnormal expression of microRNAs (miRNAs/miRs) has a critical function in the formation and progression of non-small cell lung cancer (NSCLC). Therefore, understanding the association between NSCLC and dysregulated miRNAs may allow for the identification of novel diagnostic and therapeutic biomarkers for patients with this malignancy. Previous studies have validated miR-208a as a cancer-associated miRNA in multiple different types of human cancer, however, its expression pattern and precise function in NSCLC remains yet to be elucidated. Therefore, the aims of the present study were to measure miR-208a expression in NSCLC, investigate its specific functions in NSCLC and determine its exact regulatory mechanisms. Herein, the results demonstrated that miR-208a was significantly upregulated in NSCLC tissues and cell lines compared with that in adjacent non-cancerous tissues and a non-tumorigenic bronchial epithelium BEAS-2B cell line (P<0.05, respectively). The high expression level of miR-208a exhibited an obvious association with Tumor-Node-Metastasis stage and lymph node metastasis. miR-208a silencing decreased the proliferative and invasive capacities of NSCLC cells. Notably, Src kinase signaling inhibitor 1 (SRCIN1) was verified as a potential direct target gene of miR-208a in NSCLC cells. Furthermore, SRCIN1 knockdown was able to rescue the miR-208a-mediated effects on NSCLC cells. In addition to this, silencing miR-208a expression inhibited the extracellular regulated kinase (ERK) signaling pathway in NSCLC. Overall, to the best of our knowledge, the present study is the first to provide evidence that miR-208a exerts oncogenic functions in the carcinogenesis and progression of NSCLC by directly targeting SRCIN1 and regulating the ERK pathway. Therefore, miR-208a may be developed as a potential target for treating patients with NSCLC.

SKA3 Up-regulation Promotes Lung Adenocarcinoma Growth and is a Predictor of Poor Prognosis

Objective

The objective of this research is to investigate the expression and function of SKA3 in lung adenocarcinoma.

Methods

The mRNA expression level of SKA3 in lung adenocarcinoma and its association with clinic-pathological factors were analyzed using data obtained from the TCGA database. Small interfering RNA (siRNA) for SKA3 (si-SKA3) was used to down-regulate SKA3 in A549 cells. pcDNA3.1- SKA3 was used to overexpress SKA3 in A549 cells. The proliferation ability of A549 cells was determined via MTT assay and colony formation assay. A wound healing assay was performed to examine the migration ability of A549 cells. The protein expression of p-MEK, MEK, p-ERK and ERK were determined by western blot.

Results

We found that SKA3 is up-regulated in lung adenocarcinoma compared to the normal lung tissues. Kaplan-Meier analysis showed that high SKA3 expression is markedly associated with poor prognosis in lung adenocarcinoma patients. SKA3 expression is significantly correlated with age, gender, pathologic-stage, pathologic-N and pathologic-M. Moreover, depleting SKA3 obviously inhibited A549 cell proliferation and migration in vitro, while overexpression of SKA3 notably increased A549 cell proliferation and migration. Western blot analysis showed that the protein expression ratio of p-MEK/MEK and p-ERK/ERK decreased noticeably after depleting SKA3.

Conclusion

SKA3 expression was enhanced and associated with poor prognosis in lung adenocarcinoma patients, and it might play a facilitating role in cell growth and motility by regulating the MAPK signaling pathway.

Hydroxysafflor yellow A inhibited lipopolysaccharide-induced non-small cell lung cancer cell proliferation, migration, and invasion by suppressing the PI3K/AKT/mTOR and ERK/MAPK signaling pathways

BACKGROUND

Chronic inflammation plays a significant role in the occurrence and development of non-small cell lung cancer (NSCLC). Hydroxysafflor yellow A (HSYA), a chemical compound of the yellow color pigments extracted from the safflower, has been widely used in clinical treatment with positive antioxidation, anti-inflammation, and antitumor effects. However, the role and underlying mechanisms of HYSA on development and progress in inflammation-mediated NSCLC are unknown.

METHODS

Cell counting kit-8, colony formation, EdU, cell apoptosis, wound healing, Transwell migration and invasion, and enzyme-linked immunosorbent assays; flow cytometry; and Western blotting were conducted using human NSCLC cell lines A549 and H1299.

RESULTS

Lipopolysaccharide (LPS) significantly promoted the proliferation and enhanced colony formation of A549 and H1299 cells, while HYSA notably reversed the effects of LPS. HYSA induced apoptosis of LPS-mediated A549 and H1299 cells in a dose dependent manner; and remarkably suppressed migration, invasion, and epithelial-mesenchymal transition (EMT), significantly regulated production of LPS-induced inflammation cytokines, and downregulated protein expression of PI3K/Akt/mTOR and ERK/MAPK signaling pathways in LPS-induced A549 and H1299 cells. Furthermore, PI3K (LY294002) and ERK (SCH772984) inhibitors remarkably inhibited proliferation, migration, invasion, and EMT, and induced apoptosis in LPS-mediated A549 and H1299 cells. These effects were even more obvious in the presence of HYSA and LY294002 or SCH772984 compared to those of either agent alone.

CONCLUSION

HYSA suppressed LPS-mediated proliferation, migration, invasion, and EMT in A549 and H1299 cells by inhibiting the PI3K/Akt/mTOR and ERK/MAPK signaling pathways, indicating that HYSA may be a potential candidate to treat inflammation-mediated NSCLC.

A panel of noncoding RNAs in non-small-cell lung cancer

Non-small-lung cancer (NSCLC) is the leading cause of cancer death. Early detection of NSCLC could pave the way for effective therapies. Analysis of molecular genetic biomarkers in biological fluids has been proposed as a useful tool for cancer diagnosis. Here, we aimed to develop a panel of noncoding RNAs (ncRNAs) in sputum for NSCLC early detection. Expression of 11 ncRNAs were analyzed by real-time polymerase chain reaction in sputum samples of 30 NSCLC patients and 30 sex- and age-matched cancer-free controls. Stability of endogenous microRNAs (miRNAs) in sputum was evaluated after 3 and 6 days at 4°C, 6 months, and 1 year at -80°C. Nine ncRNAs showed significant differences of their expression in sputum between NSCLC patients and controls. A logistic regression model with the best prediction was built based on miR-145, miR-126, and miR-7. The composite of the three miRNAs produced 90% sensitivity and specificity in distinguishing NSCLC patients from the controls. Results indicate that miRNAs could be useful biomarkers based on their stability under various storage conditions and maintain differential changes between cancer and control groups. Moreover, measurement of miRNAs in sputum could be a noninvasive approach for detection of lung cancer.

MicroRNA-7 Exerts Antiangiogenic Effect on Colorectal Cancer via ERK Signaling

BACKGROUND

Recent studies have suggested that microRNA-7 (miR-7) family members may play important roles in human cancer by regulating cell proliferation, apoptosis, migration, and invasion. Therefore, the present study aimed to investigate the clinical significance and biological function of miR-7 in colorectal cancer (CRC).

METHODS

Initially, cancer and adjacent tissues were collected from 76 patients with CRC. Then, microvascular density was detected using the Weidner counting method. The functional role of miR-7 in CRC was determined using ectopic expression, knockdown, and reporter assay experiments. The vasculogenic mimicry density was determined. Expression of miR-7, epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK1/2), vascular endothelial growth factor, and thrombospondin-1 was determined. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays, scratch tests, and Transwell assays were conducted to examine cell proliferation, migration, and invasion, respectively. Finally, flow cytometry was applied to evaluate cell apoptosis.

RESULTS

CRC tissues showed increased microvascular density and EGFR expression, activated ERK signaling, and miR-7 downregulation. EGFR was a target gene of miR-7. miR-7 overexpression and EGFR silencing decreased vasculogenic mimicry density, cell migration, and cell invasion, but increased cell apoptosis. In addition, miR-7 overexpression and EGFR silencing upregulated thrombospondin-1 and downregulated EGFR, ERK1/2, and vascular endothelial growth factor. Furthermore, we observed that the effect of miR-7 inhibition was abolished after EGFR silencing.

CONCLUSIONS

Overexpressed miR-7 suppresses angiogenesis of CRC cells through ERK signaling by downregulating EGFR. It may identify new targets for CRC treatment.

Integrated analysis of miRNA and mRNA expression profiles in 2-, 6-, and 12-month-old Small Tail Han Sheep ovaries reveals that oar-miR-432 downregulates RPS6KA1 expression

Small Tail Han Sheep are an excellent local sheep breed in China, and their outstanding reproductive performance is one of their very important biological characteristics. Clarifying the ovary development process of these ewes should provide a theoretical basis for improving their reproductive efficiency. In this study, we identified the differentially expressed (DE) microRNAs (miRNAs) in 2-, 6-, and 12-month-old small-tail Han sheep ovaries by constructing and analyzing the miRNA expression profiles. These findings clarify the molecular mechanisms regulating the excellent reproductive performance of small-tail Han ewes. We used RNA-Seq technology and bioinformatic to analyze these profiles. Eleven, 13, and 19 DE miRNAs were identified in the 2- vs 6-, 6- vs 12-, and 2- vs 12-month-old ovaries, respectively. In total, 54, 37, and 198 predicted target genes of these DE miRNAs were identified in these three groups, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that in the 2- vs 6-month-old ovaries, the target genes of DE known sheep miRNAs were involved in 102 GO terms and seven signaling pathways; in the 6- vs 12-month-old ovaries, the target genes of DE known sheep miRNAs were involved in 52 GO terms and three signaling pathways; and in the 2- vs 12-month-old ovaries, the target genes of DE known sheep miRNAs were involved in 88 GO terms and six signaling pathways. Three miRNA-target regulatory networks were constructed based on these DE miRNA-target interactions. Nine miRNAs were selected to confirm to the accuracy of the miRNA sequencing data with qRT-PCR. The site at which oar-miR-432 binds RPS6KA1 was determined with a dual-luciferase system. This is the first integrated analysis the expression profiles of miRNAs and their targets during ovarian development in small-tail Han sheep. These data clarify the molecular regulatory mechanisms underlying sheep ovarian development and identify biomarkers that influence the reproductive performance of small-tail Han ewes.

Overexpression of miR-758 inhibited proliferation, migration, invasion, and promoted apoptosis of non-small cell lung cancer cells by negatively regulating HMGB

Non-small cell lung cancer (NSCLC) is one of the most fatal types of cancer with significant mortality and morbidity worldwide. MicroRNAs (miRs) have been confirmed to have positive functions in NSCLC. In the present study, we try to explore the role of miR-758 in proliferation, migration, invasion, and apoptosis of NSCLC cells by regulating high-mobility group box (HMGB) 3 (HMGB3.) NSCLC and adjacent tissues were collected. Reverse transcription quantitative PCR (RT-qPCR) was employed to detect expression of miR-758 and HMGB3 in NSCLC and adjacent tissues, in BEAS-2B cells and NSCLC cell lines. The targetted relationship between miR-758 and HMGB3 was identified by dual luciferase reporter gene assay. The effects of miR-758 on proliferation, migration, invasion, cell cycle, and apoptosis of A549 cells. MiR-758 expression was lower in NSCLC tissues, which was opposite to HMGB3 expression. The results also demonstrated that miR-758 can target HMGB3. The cells transfected with miR-758 mimic had decreased HMGB3 expression, proliferation, migration, and invasion, with more arrested cells in G₁ phase and increased apoptosis. Our results supported that the overexpression of miR-758 inhibits proliferation, migration, and invasion, and promotes apoptosis of NSCLC cells by negative regulating HMGB2. The present study may provide a novel target for NSCLC treatment.

miR-7-5p inhibits cell migration and invasion in glioblastoma through targeting SATB1

MicroRNAs (miRNAs/miRs) have been revealed to influence the development and progression of glioblastoma. Although a number of miRNAs are abnormally expressed in glioblastoma it is not clear whether they are a factor associated with glioblastoma pathogenesis. In the present study, miR-7-5p was identified as being aberrantly downregulated in glioblastoma tissues and cell lines. miR-7-5p overexpression significantly decreased the migratory and invasive capacity of the cells, while miR-7-5p silencing had the opposite effect. In addition, a luciferase assay confirmed that special AT rich sequence binding protein 1 (SATB1) was a direct target gene of miR-7-5p in glioblastoma. The overexpression of SATB1 in glioblastoma was revealed to promote cell migration and invasion. In addition, SATB1 overexpression may weaken the inhibitory effect of miR-7-5p on cell migration and invasion. miR-7-5p overexpression reversed the effects of SATB1 on cell migration and invasion in glioblastoma cells. In conclusion, miR-7-5p may be a useful therapeutic target for the diagnosis and treatment of patients with glioblastoma.

Circ-U2AF1 promotes human glioma via derepressing neuro-oncological ventral antigen 2 by sponging hsa-miR-7-5p

The prognosis for human glioma, a malignant tumor of the central nervous system, is poor due to its rapid growth, genetic heterogeneity, and inadequate understanding of its underlying molecular mechanisms. Circular RNAs composed of exonic sequences, represent an understudied form of noncoding RNAs (ncRNAs) that was discovered more than a decade ago, function as microRNA sponges. We aimed to assess the relationship between circ-U2AF1 (CircRNA ID: hsa_circ_0061868) and hsa-mir-7-5p and examine their effects on proliferation, apoptosis, and the metastatic phenotype of glioma cells regulated by neuro-oncological ventral antigen 2 (NOVA2). We found that the expression levels of circ-U2AF1 and NOVA2 were upregulated, while hsa-miR-7-5p was downregulated in human glioma tissues and glioma cell lines. Our data and bioinformatic analysis indicated the association of these molecules with glioma grade, a positive correlation between circ-U2AF1 and NOVA2 expression levels and a negative correlation of hsa-miR-7-5p with both circ-U2AF1 and NOVA2, respectively. In addition, silencing of circ-U2AF1 expression resulted in increased hsa-miR-7-5p expression and decreased NOVA2 expression both in vitro and in vivo. Luciferase assay confirmed hsa-miR-7-5p as a direct target of circ-U2AF1 and NOVA2 as a direct target of hsa-miR-7-5p. Functionally, silencing of circ-U2AF1 inhibits glioma development by repressing NOVA2 via upregulating hsa-miR-7-5p both in vitro and in vivo. Thus, we assumed that circ-U2AF1 promotes glioma malignancy via derepressing NOVA2 by sponging hsa-miR-7-5p. Taken together, we suggest that circ-U2AF1 can be a prognostic biomarker and the circ-U2AF1/hsa-miR-7-5p/NOVA2 regulatory pathway may be a novel therapeutic target for treating gliomas.

miR-497 may enhance the sensitivity of non-small cell lung cancer cells to gefitinib through targeting the insulin-like growth factor-1 receptor

Background

Recently, studies have demonstrated that microRNA-497 (miR-497) plays an important role in modulating tumor cell sensitivity to chemotherapeutic drugs; however, its role in cellular resistance to the effects of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in treatment of non-small cell lung cancer (NSCLC) is not fully understood. In this study, we explored the potential of miR-497 in targeting the insulin-like growth factor-1 receptor (IGF-1R) signaling pathways to overcome gefitinib resistance.

Methods

A gefitinib resistant human lung adenocarcinoma A549 cell line (A549/GR) was established by the method of gefitinib mutagenesis culture. Next, the A549/GR cells were transfected with miR-497 mimics to establish an miR-497 overexpression model, designated A549/GR-miR497-mimic. MTT assay was used to assess cell resistance to gefitinib, and western blot assay was employed to evaluate alterations of IGF-1R and the AKT1 signaling pathway.

Results

We found that A549/GR-miR497-mimic cells (IC50 =33.76±0.97 µmol/L) were more sensitive to gefitinib than the control group (P<0.01). In addition, the expression levels of IGF-1R and phosphorylated AKT1 (p-AKT1) in A549/GR-miR497-mimic cells were reduced.

Conclusions

We demonstrated that miR-497 may have the effect of reversing gefitinib resistance and increasing the sensitivity of NSCLC cells to EGFR-TKIs by inhibiting the expression of IGF-1R and reducing activation of the downstream AKT signaling pathway. Thus, miR-497 plays a vital role in the acquired resistance to EGFR-TKIs, and it may represent a potential therapeutic strategy to treat NSCLC exhibiting resistance to EGFR-TKIs.

A negative feedback loop between nuclear factor 90 (NF90) and an anti-oncogenic microRNA, miR-7

Alterations in microRNAs (miRNAs) levels deeply correlate with tumorigenesis. However, the molecular mechanism for the regulation of the miRNA production in tumors is not fully understood. We previously reported that downregulation of miR-7, which is an anti-oncogenic miRNA, was caused by overexpression of the nuclear factor 90 (NF90)-nuclear factor 45 (NF45) complex through the binding of double-stranded (ds) RNA-binding proteins to primary miR-7, resulting in promotion of tumorigenesis (Higuchi et al 2016). During this study, we found that the level of NF90 protein was dramatically decreased by overexpression of miR-7. Interestingly, the miR-7-mediated reduction in NF90 family proteins was only observed in NF90 protein, but not in NF110 protein, which is a longer form of the NF90 gene. Luciferase reporter analysis indicated that the overexpression of miR-7 significantly repressed the luciferase activity in the coding region of NF90 mRNA harboring a predicted target sequence of miR-7. The luciferase activity of the reporter vector, which has a mutated miR-7 target site in the coding region, was the same in the control and miR-7 overexpressed cells. Furthermore, the translation of TARGET-tagged NF90 mRNA without the 3'UTR of the NF90 mRNA was inhibited by the overexpression of miR-7. These results imply that miR-7 suppresses NF90 at the protein level through the binding of miR-7 to the complementary site of the seed sequence in the coding region of the NF90 mRNA. We further confirmed increased endogenous NF90 protein levels in SK-N-SH cells transfected with antisense oligonucleotides targeting miR-7, indicating that miR-7-mediated translational repression of NF90 is a physiological event. Taken together with our previous findings (Higuchi et al 2016), it suggests that the level of NF90 is increased by a negative feedback loop between NF90 and miR-7 in tumor tissues under physiological conditions.

miR-214-3p promotes the proliferation, migration and invasion of osteosarcoma cells by targeting CADM1

Although osteosarcoma (OS) is the most common type of primary bone tumor in adolescents and young adults, its mechanism remains unclear. A previous study by the authors demonstrated that miR-214-3p was upregulated in OS patients. Therefore, the present study aimed to investigate the effect and molecular mechanism of miR-214-3p in OS cells. OS cell lines, U2OS and MNNG/HOS Cl#5, were transiently transfected with miR-214-3p mimics, a control mimic, miR-214-3p inhibitors and a control inhibitor. Subsequent assays revealed that elevated miR-214-3p promoted the proliferative, migratory and invasive abilities of OS cells, while the opposite effects were observed in cells that were transfected with miR-214-3p inhibitors. The interaction between miR-214-3p and cell adhesion molecule 1 (CADM1) 3'untranslated region (UTR) was verified by a dual luciferase assay, which indicated that the relative luciferase activity was decreased in 293T cells that were co-transfected with miR-214-3p mimic and psiCHECK2-CADM1-3'UTR compared with cells that were co-transfected with psiCHECK2-CADM1-3'UTR and control mimic. The knockdown of CADM1 using small-interfering RNA enhanced the proliferative, migratory and invasive abilities of OS cells. Furthermore, downregulated CADM1 expression increased the expression of phosphorylated P44/42 mitogen activated kinase (MAPK). In conclusion, miR-214-3p was able to directly target CADM1 and decrease its expression. This resulted in the activation of the P44/42 MAPK signaling pathway, and thereby promoted the proliferation, migration and invasion of OS cells.

Study on the mechanism behind lncRNA MEG3 affecting clear cell renal cell carcinoma by regulating miR-7/RASL11B signaling

The goal of this research was to study the relationships between maternally expressed gene 3 (MEG3), microRNA-7 (miR-7), and RASL11B, and explore their influence on the progression of clear cell renal cell carcinoma (CCRCC). Microarray analysis was conducted using the data provided by The Cancer Genome Atlas. The expression levels of MEG3 and miR-7 in CCRCC and adjacent tissue samples were ascertained by quantitative real-time polymerase chain reaction (qRT-PCR). The cell proliferation activity was unmasked by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell apoptosis and cell cycle were investigated by flow cytometry. A dual luciferase reporter assay was used to verify target relationships. Wound healing assay and transwell assay were used to detect cell migration and invasion ability. Decreased MEG3 expression was observed in CCRCC tissues and cells. Overexpression of MEG3 accelerated apoptosis; inhibited cell proliferation, migration and invasion; and induced G0/G1 phase cell cycle arrest in CCRCC. MiR-7, directly binding to MEG3, was overexpressed in the CCRCC tissues and could inhibit the apoptosis and promote the migration and invasion of CCRCC cells. RASL11B, lowly expressed in CCRCC, was a target of miR-7. After the overexpression of RASL11B, G0/G1 phase cell cycle arrest was induced; cell apoptosis was promoted; and the proliferation, invasion, and migration of CCRCC cells were inhibited. MEG3 could up-regulate RASL11B to inhibit the cell proliferation, invasion, and migration; induce G0/G1 cell cycle arrest; and promote cell apoptosis by suppressing miR-7 in CCRCC.

Endogenous Control Mechanisms of FAK and PYK2 and Their Relevance to Cancer Development

Focal adhesion kinase (FAK) and its close paralogue, proline-rich tyrosine kinase 2 (PYK2), are key regulators of aggressive spreading and metastasis of cancer cells. While targeted small-molecule inhibitors of FAK and PYK2 have been found to have promising antitumor activity, their clinical long-term efficacy may be undermined by the strong capacity of cancer cells to evade anti-kinase drugs. In healthy cells, the expression and/or function of FAK and PYK2 is tightly controlled via modulation of gene expression, competing alternatively spliced forms, non-coding RNAs, and proteins that directly or indirectly affect kinase activation or protein stability. The molecular factors involved in this control are frequently deregulated in cancer cells. Here, we review the endogenous mechanisms controlling FAK and PYK2, and with particular focus on how these mechanisms could inspire or improve anticancer therapies.

Up-regulation of ceRNA TINCR by SP1 contributes to tumorigenesis in breast cancer

Background

Assembling evidences suggested that aberrant expression of tissue differentiation-inducing non-protein coding RNA (TINCR) intimately associated with variety of human cancer. However, the expression pattern and involvement of TINCR in breast cancer has not been fully investigated. Here we set out to analyze expression of TINCR in breast cancer and elucidate its mechanistic involvement in tumor incidence and progression.

Methods

The expression of TINCR was determined by q-PCR. SP1 binding sites were analyzed by ChIP-qPCR. The relative transcription activity was measured with luciferase reporter assay. Cell viability was measured with CCK-8 method. Clonogenic capacity was evaluated by soft agar assay. Cell apoptosis was analyzed by Annexin V/7-AAD staining. The migration and invasion were determined by trans-well assay and wound healing. The tumor growth in vivo was evaluated in xenograft mice model. Protein expression was quantified by immunoblotting.

Results

TINCR was aberrantly up-regulated by SP1, which in turn stimulated cell proliferation, anchorage-independent growth and suppressed cell apoptosis in breast cancer. TINCR silencing significantly suppressed migration and invasion in vitro and xenograft tumor growth in vivo. Mechanistically, TINCR modulated KLF4 expression via competing with miR-7, which consequently contributed to its oncogenic potential. MiR-7 inhibition severely compromised TINCR silencing-elicited tumor repressive effects.

Conclusion

Our data uncovered a crucial role of TINCR-miR-7-KLF4 axis in human breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4255-3) contains supplementary material, which is available to authorized users.

CiRS-7 targeting miR-7 modulates the progression of non-small cell lung cancer in a manner dependent on NF-κB signalling

The purpose of this study was to figure out the effect of ciRS‐7/miR‐7/NF‐κB axis on the development of non‐small cell lung cancer (NSCLC). In response, the expressions of ciRS‐7, miR‐7 and NF‐κB subunit (ie RELA) within NSCLC tissues and cell lines were determined with real‐time polymerase chain reaction (RT‐PCR) and Western blot. Moreover, the NSCLC cells were transfected with pcDNA3‐ciRS‐7‐ir, pcDNA3‐ciRS‐7, miR‐NC and miR‐7 mimic. Furthermore, the targeted relationships between ciRS‐7 and miR‐7, as well as between miR‐7 and RELA, were confirmed by luciferase reporter assay. The proliferation, migration and apoptosis of NSCLC cells were, successively, measured using CCK‐8 assay, wound‐healing assay and flow cytometry test. Consequently, ciRS‐7, miR‐7, histopathological grade, lymph node metastasis and histopathological stage could independently predict the prognosis of patients with NSCLC (all P < .05). Moreover, remarkably up‐regulated ciRS‐7 and RELA expressions, as along with down‐regulated miR‐7 expressions, were found within NSCLC tissues and cells in comparison with normal ones (P < .05). Besides, overexpressed ciRS‐7 and underexpressed miR‐7 were correlated with increased proliferation, migration and invasion, yet reduced apoptosis rate of NSCLC cells (P < .05). More than that, ciRS‐7 specifically targeted miR‐7 to reduce its expressions (P < .05). Ultimately, the NSCLC cells within miR‐7 + RELA group were observed with superior proliferative, migratory and invasive capabilities than those within miR‐7 group (P < .05), and RELA expression was also significantly modified by both ciRS‐7 and miR‐7 (P < .05). In conclusion, the ciRS‐7/miR‐7/NF‐kB axis could exert pronounced impacts on the proliferation, migration, invasion and apoptosis of NSCLC cells.

Enhanced Chemotherapeutic Efficacy of Paclitaxel Nanoparticles Co-delivered with MicroRNA-7 by Inhibiting Paclitaxel-Induced EGFR/ERK pathway Activation for Ovarian Cancer Therapy

Chemotherapy-induced activation of cell survival pathways leads to drug resistance. MicroRNAs (miRNAs) post-transcriptionally regulate gene expression in many biological pathways. Paclitaxel (PTX) is one of the first-line chemotherapy drugs for ovarian cancer, and it induces the activation of the epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinase (ERK) pathway that leads to tumor cell proliferation, survival, invasion, and drug resistance. MicroRNA-7 (miR-7) has the ability to suppress the EGFR/ERK pathway. To sensitize chemotherapy, we developed monomethoxy(poly(ethylene glycol))-poly(d,l-lactide- co-glycolide)-poly(l-lysine) nanoparticles for the simultaneous co-delivery of PTX and miR-7. The resulting PTX/miR-7 nanoparticles (P/MNPs) protect miRNA from degradation, possess a sequential and controlled release of drugs, improve the transfection efficiency of miRNA, decrease the half-maximal inhibitory concentration of PTX, and increase the apoptosis of ovarian cancer cells. The chemotherapeutic efficacy of PTX is prominently enhanced in vitro and in vivo via the inhibition of PTX-induced EGFR/ERK pathway activation by miR-7. Our studies in P/MNPs reveal a novel paradigm for a dual-drug-delivery system of chemotherapeutics and gene therapy in treating cancers.

Silencing of miR-193a-5p increases the chemosensitivity of prostate cancer cells to docetaxel

BACKGROUND

Docetaxel-based chemotherapy failure in advanced prostate carcinoma has partly been attributed to the resistance of prostate cancer (PC) cells to docetaxel-induced apoptosis. Hence, there is an urgent need to identify mechanisms of docetaxel chemoresistance and to develop new combination therapies.

METHODS

miR-193a-5p level was evaluated by qPCR in prostate tissues and cell lines, and its expression in the tissues was also examined by in situ hybridization. PC cell line (PC3 cell) was transfected with miR-193a-5p mimic or its inhibitor, and then cell apoptosis and the expression of its downstream genes Bach2 and HO-1 were detected by TUNEL staining and Western blotting. Luciferase reporter assay was used to detect the effect of miR-193a-5p and Bach2 on HO-1 expression. Xenograft animal model was used to test the effect of miR-193a-5p and docetaxel on PC3 xenograft growth.

RESULTS

miR-193a-5p was upregulated in PC tissues and PC cell lines, with significant suppression of PC3 cell apoptosis induced by oxidative stress. Mechanistically, miR-193a-5p suppressed the expression of Bach2, a repressor of the HO-1 gene, by directly targeting the Bach2 mRNA 3'-UTR. Docetaxel treatment modestly decreased Bach2 expression and increased HO-1 level in PC3 cells, whereas a modest increase of HO-1 facilitated docetaxel-induced apoptosis. Notably, docetaxel-induced miR-193a-5p upregulation, which in turn inhibits Bach2 expression and thus relieves Bach2 repression of HO-1 expression, partly counteracted docetaxel-induced apoptosis, as evidenced by the increased Bcl-2 and decreased Bax expression. Accordingly, silencing of miR-193a-5p enhanced sensitization of PC3 cells to docetaxel-induced apoptosis. Finally, depletion of miR-193a-5p significantly reduced PC xenograft growth in vivo.

CONCLUSIONS

Silencing of miR-193a-5p or blockade of the miR-193a-5p-Bach2-HO-1 pathway may be a novel therapeutic approach for castration-resistant PC.

Clinical values of circular RNA 0000181 in the screening of gastric cancer

BACKGROUND

Circular RNAs (circRNAs) are recently found involved in cancer occurrence and development. However, their values in the diagnosis of gastric cancers are largely unknown. In this study, we analyzed the values of hsa_circ_0000181 in the diagnosis of gastric cancer.

METHODS

Using divergent primers, hsa_circ_0000181 expression levels in fresh gastric cancer tissues and paired adjacent non-tumorous tissues, and plasmas from patient with gastric cancer and health people were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The association between hsa_circ_0000181 levels and the clinicopathologic features of patients with gastric cancer was further analyzed. Finally, to evaluate the diagnostic value, receiver operating characteristic (ROC) curve was established.

RESULTS

Hsa_circ_0000181 levels in gastric cancer tissues and plasma from gastric cancer patients were significantly decreased than those in paired adjacent non-tumorous tissues (P < .001) and healthy people (P < .001), respectively. Furthermore, hsa_circ_0000181 expression in gastric cancer tissues was significantly correlated with tumor diameter (P = .027), lymphatic metastasis (P = .044), distal metastasis (P = .023), and carbohydrate antigen 19-9 (P = .031). Its decreased levels in patients' plasma were significantly associated with differentiation (P = .038) and carcinoembryonic antigen (P = .037). The areas under ROC curve were 0.756. The specificity of tissue hsa_circ_0000181 and sensitivity of plasma hsa_circ_0000181 were 85.2% and 99.0%, respectively.

CONCLUSIONS

Thanks to the high stability, tissue and plasma hsa_circ_0000181 may be a novel biomarker for the diagnosis of gastric cancer.