MicroRNA-328 is associated with (non-small) cell lung cancer (NSCLC) brain metastasis and mediates NSCLC migration

MiRNAs as new potential biomarkers and therapeutic targets in brain metastasis

Brain metastases represent a formidable challenge in cancer management, impacting a significant number of patients and contributing significantly to cancer-related mortality. Conventional diagnostic methods frequently fall short, underscoring the imperative for non-invasive alternatives. Non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), present promising avenues for exploration. These ncRNAs exert influence over the prognosis and treatment resistance of brain metastases, offering valuable insights into underlying mechanisms and potential therapeutic targets. Dysregulated ncRNAs have been identified in brain metastases originating from various primary cancers, unveiling opportunities for intervention and prevention. The analysis of ncRNA expression in bodily fluids, such as serum and cerebrospinal fluid, provides a noninvasive means to differentiate brain metastases from primary tumors. NcRNAs, particularly miRNAs, assume a pivotal role in orchestrating the immune response within the brain microenvironment. MiRNAs exhibit promise in diagnosing brain metastases, effectively distinguishing between normal and cancer cells, and pinpointing the tissue of origin for metastatic brain tumors. The manipulation of miRNAs holds substantial potential in cancer treatment, offering the prospect of reducing toxicity and enhancing efficacy. Given the limited treatment options and the formidable threat of brain metastases in cancer patients, non-coding RNAs, especially miRNAs, emerge as beacons of hope, serving as both diagnostic tools and therapeutic targets. Further clinical studies are imperative to validate the specificity and sensitivity of ncRNAs, potentially reshaping approaches to tackle this challenge and elevate treatment outcomes for affected patients.

A Review of Recent Advances in the Molecular Mechanisms Underlying Brain Metastasis in Lung Cancer

Brain metastasis from lung cancer is a prevalent mode of treatment failure associated with a poor prognosis. The incidence of brain metastasis has recently shown a dramatic increase. The early detection and risk stratification of lung cancer-related brain metastasis would be highly advantageous for patients. However, our current knowledge and comprehension of the underlying mechanisms driving brain metastasis in lung cancer pose significant challenges. This review summarizes the mechanisms underlying brain metastasis, focusing on the intricate interplay between lung cancer-derived tumor cells and the unique characteristics of the brain, recent advancements in the identification of driver genes, concomitant genes, epigenetic features, including miRNAs and long noncoding RNAs, as well as the molecular characterization of brain metastasis originating from other organs, which may further enhance risk stratification and facilitate precise treatment strategies.

The role of microRNAs in brain metastasis

Brain metastasis (BM) is the most common type of brain tumor and frequently foreshadows disease progression and poor overall survival with patients having a median survival of 6 months. 70,000 new cases of BM are diagnosed each year in the United States (US) and the incidence rate for BM is increasing with improved detection. MicroRNAs (miRNAs) are small non-coding RNAs that serve as critical regulators of gene expression and can act as powerful oncogenes and tumor suppressors. MiRNAs have been heavily implicated in cancer and proposed as biomarkers or therapeutic targets or agents. In this review, we summarize an extensive body of scientific work investigating the role of microRNAs in BM. We discuss miRNA dysregulation, functions, targets, and mechanisms of action in BM and present the current standing of miRNAs as biomarkers and potential therapeutics for BM. We conclude with future directions of miRNA basic and clinical research in BM.

Diverse functions of miR-328 in the carcinogenesis

MicroRNA-328 (miR-328) is an RNA gene that is primarily associated with lung cancer, and its encoding gene is located on 16q22.1. Expression of miR-328 has been observed in lung and esophagus tissues based on RNAseq data. Although several studies have aimed at the detection of miR-328 levels in tumor tissues, there is an obvious discrepancy between the results of these studies. Even in a certain type of cancer, some studies have reported up-regulation of miR-328 in cancerous tissues versus control tissues, while others have reported its down-regulation. This discrepancy might be attributed to different stages/grades of tumor tissues or other clinical characteristics. This review article focuses on the available literature to explore the functions of miR-328 in the development of human carcinogenesis.

The Role of Exosome-Derived microRNA on Lung Cancer Metastasis Progression

The high mortality from lung cancer is mainly attributed to the presence of metastases at the time of diagnosis. Despite being the leading cause of lung cancer death, the underlying molecular mechanisms driving metastasis progression are still not fully understood. Recent studies suggest that tumor cell exosomes play a significant role in tumor progression through intercellular communication between tumor cells, the microenvironment, and distant organs. Furthermore, evidence shows that exosomes release biologically active components to distant sites and organs, which direct metastasis by preparing metastatic pre-niche and stimulating tumorigenesis. As a result, identifying the active components of exosome cargo has become a critical area of research in recent years. Among these components are microRNAs, which are associated with tumor progression and metastasis in lung cancer. Although research into exosome-derived microRNA (exosomal miRNAs) is still in its early stages, it holds promise as a potential target for lung cancer therapy. Understanding how exosomal microRNAs promote metastasis will provide evidence for developing new targeted treatments. This review summarizes current research on exosomal miRNAs' role in metastasis progression mechanisms, focusing on lung cancer.

Immunotherapy and brain metastasis in lung cancer: connecting bench side science to the clinic

Brain metastases (BMs) are the most common form of intracranial malignant neoplasms in adults, with a profound impact on quality of life and traditionally associated with a dismal prognosis. Lung cancer accounts for approximately 40%-50% of BM across different tumors. The process leading to BMs is complex and includes local invasion, intravasation, tumor cells circulation into the bloodstream, disruption of the blood-brain barrier, extravasation of tumor cells into the brain parenchyma, and interaction with cells of the brain microenvironment, among others. Once the tumor cells have seeded in the brain parenchyma, they encounter different glial cells of the brain, as well as immune cells. The interaction between these cells and tumor cells is complex and is associated with both antitumoral and protumoral effects. To overcome the lethal prognosis associated with BMs, different treatment strategies have been developed, such as immunotherapy with immune checkpoint inhibitors, particularly inhibitors of the PD-1/PD-L1 axis, which have demonstrated to be an effective treatment in both non-small cell lung cancer and small cell lung cancer. These antibodies have shown to be effective in the treatment of BM, alone or in combination with chemotherapy or radiotherapy. However, many unsolved questions remain to be answered, such as the sequencing of immunotherapy and radiotherapy, the optimal management in symptomatic BMs, the role of the addition of anti-CTLA-4 antibodies, and so forth. The complexity in the management of BMs in the era of immunotherapy requires a multidisciplinary approach to adequately treat this devastating event. The aim of this review is to summarize evidence regarding epidemiology of BM, its pathophysiology, current approach to treatment strategies, as well as future perspectives.

The origin of brain malignancies at the blood-brain barrier

Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.

Cell-Free miRNAs as Non-Invasive Biomarkers in Brain Tumors

Diagnosing brain tumors, especially malignant variants, such as glioblastoma, medulloblastoma, or brain metastasis, presents a considerable obstacle, while current treatment methods often yield unsatisfactory results. The monitoring of individuals with brain neoplasms becomes burdensome due to the intricate tumor nature and associated risks of tissue biopsies, compounded by the restricted accuracy and sensitivity of presently available non-invasive diagnostic techniques. The uncertainties surrounding diagnosis and the tumor's reaction to treatment can lead to delays in critical determinations that profoundly influence the prognosis of the disease. Consequently, there exists a pressing necessity to formulate and validate dependable, minimally invasive biomarkers that can effectively diagnose and predict brain tumors. Cell-free microRNAs (miRNAs), which remain stable and detectable in human bodily fluids, such as blood and cerebrospinal fluid (CSF), have emerged as potential indicators for a range of ailments, brain tumors included. Numerous investigations have showcased the viability of profiling cell-free miRNA expression in both CSF and blood samples obtained from patients with brain tumors. Distinct miRNAs demonstrate varying expression patterns within CSF and blood. While cell-free microRNAs in the blood exhibit potential in diagnosing, prognosticating, and monitoring treatment across diverse tumor types, they fall short in effectively diagnosing brain tumors. Conversely, the cell-free miRNA profile within CSF demonstrates high potential in delivering precise and specific evaluations of brain tumors.

Haplotype-GGGT in long non-coding RNA MALAT1 inhibits brain metastatic lung cancer and lymph nodes of lung cancer via the MALAT1/miR-328/KATNB1

The up-regulation of Katanin P8 has been reported to be correlated with a larger tumor size and lymph node metastasis in non-small-cell lung cancer (NSCLC) patients. And lncRNA MALAT1 was demonstrated to promote the proliferation of chronic myeloid leukemia cells via modulating miR-328. 135 lung cancer patients were divided into 6 groups according to their genotypes of MALAT1. The expression of KATNB1 was negatively correlated with the GGGT genotype of MALAT1. Decreased lymph node size and tumor size of brain metastatic lung were observed in patients with GGGT genotype of MALAT1. The luciferase activities of MALAT1 and KATNB1 were remarkably suppressed by miR-328 in A549 and H460. And the down-regulation of MALAT1 or up-regulation of miR-328 significantly repressed the KATNB1 expression in A549 and H460 cells. MALAT1 expression was reduced in patients carrying haplotype GGGT. A signaling pathway of MALAT1/miR-328/KATNB1 was established to explain the down-regulation of KATNB1 mRNA in patients carrying haplotype GGGT and reduced lymph node size in lung cancer and tumor size in brain metastatic lung cancer.

Advances in the Molecular Landscape of Lung Cancer Brain Metastasis

Lung cancer is one of the most frequent tumors that metastasize to the brain. Brain metastasis (BM) is common in advanced cases, being the major cause of patient morbidity and mortality. BMs are thought to arise via the seeding of circulating tumor cells into the brain microvasculature. In brain tissue, the interaction with immune cells promotes a microenvironment favorable to the growth of cancer cells. Despite multimodal treatments and advances in systemic therapies, lung cancer patients still have poor prognoses. Therefore, there is an urgent need to identify the molecular drivers of BM and clinically applicable biomarkers in order to improve disease outcomes and patient survival. The goal of this review is to summarize the current state of knowledge on the mechanisms of the metastatic spread of lung cancer to the brain and how the metastatic spread is influenced by the brain microenvironment, and to elucidate the molecular determinants of brain metastasis regarding the role of genomic and transcriptomic changes, including coding and non-coding RNAs. We also present an overview of the current therapeutics and novel treatment strategies for patients diagnosed with BM from NSCLC.

Micro-ribonucleic acids (miRNAs) and a proteomic profile in lung adenocarcinoma cases with brain metastasis

Background

Brain metastasis (BM) is the main cause of death of individuals with lung adenocarcinoma (LAC). Biomarkers with high sensitivity and specificity for the early detection and treatment of BM of LAC urgently need to be identified. In this study, we analyzed the pathogenesis of LAC-induced BM by detecting micro-ribonucleic acid (miRNA) and proteome expression differences between primary LAC lesion and BM tissue specimens to identify biomarkers of LAC-associated BM and develop potential therapeutic targets.

Methods

The miRNA and protein profiles of non-metastatic primary LAC and BM cases were examined to further explore the mechanism of BM. The roles and interactions of differential miRNAs and proteins were subject to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The interactions of differential miRNAs and proteins were analyzed by R software and depicted using Cytoscape.

Results

Compared to the LAC tissue specimens, 16 and 4 miRNAs showed increased and reduced levels, respectively, in the BM tissue specimens, and 53 proteins were upregulated, and 35 proteins were downregulated. The enrichment pathway analysis showed the nuclear factor kappa B (NF-κB) signaling and the primary immunodeficiency pathways played important roles in the pathogenetic mechanisms of BM in LAC.

Conclusions

This study extended understandings of the regulatory network of miRNAs and proteins and provided novel insights into the pathogenic mechanisms of BM in LAC at the miRNA and protein levels.

miRSCAPE - inferring miRNA expression from scRNA-seq data

Our understanding of miRNA activity at cellular resolution is thwarted by the inability of standard scRNA-seq protocols to capture miRNAs. We introduce a novel tool, miRSCAPE, to infer miRNA expression in a sample from its RNA-seq profile. We establish miRSCAPE’s accuracy in 10 tumor and normal cohorts demonstrating its superiority over alternatives. miRSCAPE accurately infers cell type-specific miRNA activities (predicted versus observed fold-difference correlation ∼0.81) in two independent scRNA-seq datasets. We apply miRSCAPE to infer miRNA activities in scRNA clusters in pancreatic and lung adenocarcinomas, as well as in 56 cell types in the human cell landscape (HCL). In pancreatic and breast cancer scRNA-seq data, miRSCAPE recapitulates miRNAs associated with stemness and epithelial-mesenchymal transition (EMT) cell states, respectively. Overall, miRSCAPE recapitulates and refines miRNA biology at cellular resolution. miRSCAPE is freely available and is easily applicable to scRNA-seq data to infer miRNA activities at cellular resolution.

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Novel machine learning-based tool to infer miRNA expression at single cell level

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Predicts miRNA activity with high accuracy in various contexts

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Recaps miRNAs associated with specific cellular states and suggests novel candidates

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Provides a general framework to predict other types of molecular data at a single cell

The Significance of MicroRNAs in the Molecular Pathology of Brain Metastases

Brain metastases are the most frequent intracranial tumors in adults and the cause of death in almost one-fourth of cases. The incidence of brain metastases is steadily increasing. The main reason for this increase could be the introduction of new and more efficient therapeutic strategies that lead to longer survival but, at the same time, cause a higher risk of brain parenchyma infiltration. In addition, the advances in imaging methodology, which provide earlier identification of brain metastases, may also be a reason for the higher recorded number of patients with these tumors. Metastasis is a complex biological process that is still largely unexplored, influenced by many factors and involving many molecules. A deeper understanding of the process will allow the discovery of more effective diagnostic and therapeutic approaches that could improve the quality and length of patient survival. Recent studies have shown that microRNAs (miRNAs) are essential molecules that are involved in specific steps of the metastatic cascade. MiRNAs are endogenously expressed small non-coding RNAs that act as post-transcriptional regulators of gene expression and thus regulate most cellular processes. The dysregulation of these molecules has been implicated in many cancers, including brain metastases. Therefore, miRNAs represent promising diagnostic molecules and therapeutic targets in brain metastases. This review summarizes the current knowledge on the importance of miRNAs in brain metastasis, focusing on their involvement in the metastatic cascade and their potential clinical implications.

Liquid biopsies to occult brain metastasis

Brain metastasis (BrM) is a major problem associated with cancer-related mortality, and currently, no specific biomarkers are available in clinical settings for early detection. Liquid biopsy is widely accepted as a non-invasive method for diagnosing cancer and other diseases. We have reviewed the evidence that shows how the molecular alterations are involved in BrM, majorly from breast cancer (BC), lung cancer (LC), and melanoma, with an inception in how they can be employed for biomarker development. We discussed genetic and epigenetic changes that influence cancer cells to breach the blood-brain barrier (BBB) and help to establish metastatic lesions in the uniquely distinct brain microenvironment. Keeping abreast with the recent breakthroughs in the context of various biomolecules detections and identifications, the circulating tumor cells (CTC), cell-free nucleotides, non-coding RNAs, secretory proteins, and metabolites can be pursued in human body fluids such as blood, serum, cerebrospinal fluid (CSF), and urine to obtain potential candidates for biomarker development. The liquid biopsy-based biomarkers can overlay with current imaging techniques to amplify the signal viable for improving the early detection and treatments of occult BrM.

[Research Progress on Risk Factors of Brain Metastasis in Non-small Cell Lung Cancer]

Brain metastasis of non-small cell lung cancer (NSCLC) is a common treatment failure mode, and the median survival time of NSCLC patients with brain metastasis is only 1 mon-2 mon. Prophylactic cranial irradiation (PCI) can delay the occurrence of brain metastasis, but the survival benefits of NSCLC patients are still controversial. It is particularly important to identify the patients who are most likely to benefit from PCI. This article reviews the high risk factors of brain metastasis in NSCLC.
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MiR-224 promotes lymphatic metastasis by targeting ANGPTL1 in non-small-cell lung carcinoma

BACKGROUND

MicroRNAs can regulate tumor metastasis either as oncomiRs or suppressor miRNAs. Here, we investigated the role of microRNA 224 (miR-224) in lymphatic metastasis of non-small-cell lung cancer (NSCLC).

METHODS

The expression of miR-224 was demonstrated by a validation cohort of 156 lung cancer patients (77 cases with lymphatic metastasis) by quantitative polymerase chain reaction (qPCR). In vitro and in vivo experiments were performed to study the malignant phenotype after upregulation and inhibition of miR-224 expression. Furthermore, the direct target genes of miR-224 were determined by a luciferase reporter assay.

RESULTS

First, miR-224 was identified as a highly expressed miRNA in tumor tissues with lymphatic metastasis, with an area under the curve (AUC) of 0.57 as determined by qPCR analysis of a validation cohort of 156 lung cancer patients. Then, in vitro and in vivo experiments indicated that forced expression of miR-224 in H1299 cells promoted not only cell viability, plate colony formation, migration and invasion in vitro but also tumor growth and lung metastasis in vivo. Consistently, inhibition of miR-224 suppressed malignant characteristics both in vitro and in vivo. Moreover, molecular mechanistic research suggested that miR-224 enhanced NSCLC by directly targeting the tumor suppressor angiopoietin-like protein (ANGPTL).

CONCLUSIONS

Overall, the collective findings demonstrate that miR-224 is a potential biomarker for the prediction of lymphatic metastasis of NSCLC.

Downregulation of NCL attenuates tumor formation and growth in HeLa cells by targeting the PI3K/AKT pathway

BACKGROUND

Nucleolin (NCL, C23) is a multifunctional phosphoprotein that plays a vital role in modulating the survival, proliferationand apoptosis of cancer cells. However, the effects of NCL on cervical cancer and the underlying mechanisms behind this are poorly understood.

METHODS

Lentiviral transfection technology was used to construct NCL knockdown cell lines. MTT, colony formation assays, and tumorigenic assays in vivo were performed to observe cell proliferation. HOECHST 33342 staining, flow cytometry, and caspase activity assay were used to test cell apoptosis. RNA-Seq, Western blotting, and RT-PCR were conducted to investigate the specific molecular mechanism.

RESULTS

NCL knockdown inhibited cell proliferation and promoted apoptosis both in vivo and in vitro. Mechanistic studies revealed that NCL knockdown inhibited the PI3K/AKT pathway by upregulating FGF, ITGA, TNXB, VEGF, Caspase 3, and Bax, as well as by downregulating AKT, GNB4, CDK6, IL6R, LAMA, PDGFD, PPP2RSA and BCL-2. In addition, the expression levels of apoptosis-related genes after using a PI3K inhibitor LY294002 were consistent with shRNA studies, while treatment with a 740Y-P agonist showed the opposite effect.

CONCLUSIONS

Our findings indicate that downregulation of NCL may be a novel treatment strategy forcervical cancer.

Overexpression of miR-328-5p influences cell growth and migration to promote NSCLC progression by targeting LOXL4

Background

Lung cancer is the leading cause of cancer-associated mortality worldwide, and most lung cancers are classified as non-small cell lung cancer (NSCLC). MiR-328 influence the progression of multiple tumors, but the role of miR-328-5p in NSCLC has not been elucidated. The aim of this study was to illuminate the oncogenic role and potential molecular mechanisms of the miR-328-5p and lysyl oxidase like 4 (LOXL4) in NSCLC.

Methods

Expression of miR-328-5p was detected by real-time quantitative polymerase chain reaction (qRT-PCR) in tumor and non-tumor adjacent tissues. After Lentivirus-miR-328-5p was employed to intervene this miRNA in NSCLC cell lines, RT-qPCR was used to detect the expression levels of miR-328-5p. Cell Counting Kit-8 (CCK-8), cell colony formation, flow cytometry, wound healing, Transwell assays were used to determine the malignant phenotypes of NSCLC cells. Nude mice models of subcutaneous tumors were established to observe the effect of miR-328-5p on tumorigenesis. Targeting the 3'UTR of LOXL4 by miR-328-5p was verified by integrated analysis including transcriptome sequencing, dual-luciferase and western-blot assays.

Results

High miR-328-5p level was observed in NSCLC cells from The Cancer Genome Atlas (TCGA) database and tumor tissues collected from NSCLC patients. Overexpressed miR-328-5p promoted NSCLC cell proliferation, survival, and migration, and promoted tumor growth in vivo. Knockdown of miR-328-5p suppressed tumorigenic activities. Transcriptome sequencing analysis revealed that LOXL4 was downregulated by miR-328-5p, which was confirmed by dual-luciferase reporter and western-blot assays.

Conclusions

miR-328-5p showed targeted regulation of LOXL4 to promote cell proliferation and migration in NSCLC.

Clinical Biomarkers for Early Identification of Patients with Intracranial Metastatic Disease

Simple Summary

The development of brain metastases, or intracranial metastatic disease (IMD), is a serious and life-altering complication for many patients with cancer. While there have been substantial advancements in the treatments available for IMD and in our understanding of its pathogenesis, conventional methods remain insufficient to detect IMD at an early stage. In this review, we discuss current research on biomarkers specific to IMD. In particular, we highlight biomarkers that can be easily accessed via the bloodstream or cerebrospinal fluid, including circulating tumor cells and DNA, as well as advanced imaging techniques. The continued development of these assays could enable clinicians to detect IMD prior to the development of IMD-associated symptoms and ultimately improve patient prognosis and survival.

Abstract

Nearly 30% of patients with cancer will develop intracranial metastatic disease (IMD), and more than half of these patients will die within a few months following their diagnosis. In light of the profound effect of IMD on survival and quality of life, there is significant interest in identifying biomarkers that could facilitate the early detection of IMD or identify patients with cancer who are at high IMD risk. In this review, we will highlight early efforts to identify biomarkers of IMD and consider avenues for future investigation.

Zebrafish xenograft model for studying mechanism and treatment of non-small cell lung cancer brain metastasis

Background

Brain metastasis (BM) is thought to be related to the mortality and poor prognosis of non-small cell lung cancer (NSCLC). Despite promising development of NSCLC treatment, the treatment of NSCLC BM is still not optimistic due to the existence of the blood-brain barrier (BBB) that prevent drug penetration, as well as the short median survival time of the patients left for treatment. In this context, further development of quick and effective pre-clinical models is needed in NSCLC BM treatment. Here, we report a model system using zebrafish to promote the development of drugs for patients with NSCLC BM.

Methods

Three different NSCLC cell lines (H1975, A549 and H1299) were used to establish zebrafish BM models. The embryo age and cell number for injection were first optimized. Metastatic cells were observed in the brain blood vessels of zebrafish and were verified by hematoxylin-eosin (HE) staining. Then, the metastasis potentials of H1975 and A549 with manipulated microRNA-330-3p (miR-330-3p) expression were also investigated. Finally, sensitivities of H1975 and A549 to osimertinib and gefitinib were tested.

Results

This zebrafish BM model could distinguish NSCLC cell lines with different BM potential. Over-expressed miR-330-p significantly improved the BM potential of the A549 cells while knockdown miR-330-p reduced the BM ability of the H1975 cells. Both osimertinib and gefitinib showed inhibition effect in zebrafish BM model with the inhibition rate higher than 50 %. H1975 cell showed much higher sensitivity to osimertinib rather than gefitinib both in vivo and in vitro.

Conclusions

We established zebrafish brain metastasis model for studying mechanism and treatment of NSCLC BM. This study provided a useful model for NSCLC brain metastasis that could be used to study the mechanism that drive NSCLC cells to the brain as well as identify potential therapeutic options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02173-5.

Cancer driver gene and non-coding RNA alterations as biomarkers of brain metastasis in lung cancer: A review of the literature

Brain metastasis (BM) is the most common event in patients with lung cancer. Despite multimodal treatments and advances in systemic therapies, development of BM remains one of the main factors associated with poor prognosis and mortality in patients with lung cancer. Therefore, better understanding of mechanisms involved in lung cancer brain metastasis (LCBM) is of great importance to suppress cancer cells and to improve the overall survival of patients. Several cancer-related genes such as EGFR and KRAS have been proposed as potential predictors of LCBM. In addition, there is ample evidence supporting crucial roles of non-coding RNAs (ncRNAs) in mediating LCBM. In this review, we provide comprehensive information on risk assessment, predictive, and prognostic panels for early detection of BM in patients with lung cancer. Moreover, we present an overview of LCBM molecular mechanisms, cancer driver genes, and ncRNAs which may predict the risk of BM in lung cancer patients. Recent clinical studies have focused on determining mechanisms involved in LCBM and their association with diagnosis, prognosis, and treatment outcomes. These studies have shown that alterations in EGFR, KRAS, BRAF, and ALK, as the most frequent coding gene alterations, and dysregulation of ncRNAs such as miR-423, miR-330-3p, miR-145, piR-651, and MALAT1 can be considered as potential biomarkers of LCBM.

Narrative review: molecular and genetic profiling of oligometastatic non-small cell lung cancer

Objective

The objectives of this review are to discuss: the definition, clinical and biologic features of oligometastatic non-small cell lung cancer (NSCLC), as well as the concept of treating oligoprogression in oligometastatic NSCLC.

Background

A substantial proportion of patients diagnosed with lung cancer present with metastatic disease, and a large portion of patients who present with localized disease later develop metastases. Oligometastatic NSCLC is defined as an intermediate state between localized and widespread metastatic disease, where there may be a role for curative localized therapy approach by treating the primary tumor and all metastases with radiotherapy or surgery. Despite the increasing application of this approach in patients with lung cancer, the identification of patients who might benefit from this approach is yet to be well characterized.

Methods

After a systematic review of the literature, a PubMed search was performed using the English language and the key terms: oligometastatic, non-small cell lung cancer (NSCLC), localized consolidative treatment (LCT), biomarkers, biologic features, clinical features. Over 500 articles were retrieved between 1889–2021. A total of 178 papers discussing the definition, clinical and biologic factors leading to oligometastatic NSCLC were reviewed and included in the discussion of this paper.

Conclusions

Oligometastatic NSCLC is a unique entity. Identifying patients who have oligometastatic NSCLC accurately using a combination of clinical and biologic features and treating them with localized consolidative approach appropriately results in improvement of outcome. Further understanding of the molecular mechanisms driving the formation of oligometastatic NSCLC is an important area of focus for future studies.

Molecular Mechanisms of Antiproliferative and Apoptosis Activity by 1,5-Bis(4-Hydroxy-3-Methoxyphenyl)1,4-Pentadiene-3-one (MS13) on Human Non-Small Cell Lung Cancer Cells

Diarylpentanoid (DAP), an analog that was structurally modified from a naturally occurring curcumin, has shown to enhance anticancer efficacy compared to its parent compound in various cancers. This study aims to determine the cytotoxicity, antiproliferative, and apoptotic activity of diarylpentanoid MS13 on two subtypes of non-small cell lung cancer (NSCLC) cells: squamous cell carcinoma (NCI-H520) and adenocarcinoma (NCI-H23). Gene expression analysis was performed using Nanostring PanCancer Pathways Panel to determine significant signaling pathways and targeted genes in these treated cells. Cytotoxicity screening revealed that MS13 exhibited greater inhibitory effect in NCI-H520 and NCI-H23 cells compared to curcumin. MS13 induced anti-proliferative activity in both cells in a dose- and time-dependent manner. Morphological analysis revealed that a significant number of MS13-treated cells exhibited apoptosis. A significant increase in caspase-3 activity and decrease in Bcl-2 protein concentration was noted in both MS13-treated cells in a time- and dose-dependent manner. A total of 77 and 47 differential expressed genes (DEGs) were regulated in MS13 treated-NCI-H520 and NCI-H23 cells, respectively. Among the DEGs, 22 were mutually expressed in both NCI-H520 and NCI-H23 cells in response to MS13 treatment. The top DEGs modulated by MS13 in NCI-H520—DUSP4, CDKN1A, GADD45G, NGFR, and EPHA2—and NCI-H23 cells—HGF, MET, COL5A2, MCM7, and GNG4—were highly associated with PI3K, cell cycle-apoptosis, and MAPK signaling pathways. In conclusion, MS13 may induce antiproliferation and apoptosis activity in squamous cell carcinoma and adenocarcinoma of NSCLC cells by modulating DEGs associated with PI3K-AKT, cell cycle-apoptosis, and MAPK pathways. Therefore, our present findings could provide an insight into the anticancer activity of MS13 and merits further investigation as a potential anticancer agent for NSCLC cancer therapy.

Fatty acid β-oxidation promotes breast cancer stemness and metastasis via the miRNA-328-3p-CPT1A pathway

MicroRNAs (miRNA) have been shown to be associated with tumor diagnosis, prognosis, and therapeutic response. MiR-328-3p plays a significant role in breast cancer growth; however, its actual function and how it modulates specific biological functions is poorly understood. Here, miR-328-3p was significantly downregulated in breast cancer, especially in patients with metastasis. Mitochondrial carnitine palmitoyl transferase 1a (CPT1A) is a downstream target gene in the miR-328-3p-regulated pathway. Furthermore, the miR-328-3p/CPT1A/fatty acid β-oxidation/stemness axis was shown responsible for breast cancer metastasis. Collectively, this study revealed that miR-328-3p is a potential therapeutic target for the treatment of breast cancer patients with metastasis, and also a model for the miRNA-fatty acid β-oxidation-stemness axis, which may assist inunderstanding the cancer stem cell signaling functions of miRNA.

LncRNA LOC146880 promotes esophageal squamous cell carcinoma progression via miR-328-5p/FSCN1/MAPK axis

We investigated the role of long non-coding RNA (lncRNA) LOC146880 in esophageal squamous cell carcinoma (ESCC). LOC146880 was significantly upregulated in ESCC tissues (n = 21) and cell lines compared to the corresponding controls. Higher LOC146880 expression correlated with poorer overall survival (OS) of ESCC patients. Moreover, CREB-binding protein (CBP) and H3K27 acetylation levels were significantly higher in the LOC146880 promoter in ESCC cell lines than in the controls. LOC146880 silencing inhibited in vitro proliferation, invasion, migration, and epithelial-mesenchymal transition of ESCC cells. LOC146880 silencing also induced G1-phase cell cycle arrest and apoptosis in ESCC cells. Bioinformatics analysis, dual luciferase reporter assays, and RNA immunoprecipitation assays showed that LOC146880 regulates FSCN1 expression in ESCC cells by sponging miR-328-5p. Moreover, FSCN1 expression correlated with activation of the MAPK signaling pathway in ESCC cells and tissues. In vivo xenograft tumor volume and liver metastasis were significantly reduced in nude mice injected with LOC146880-silenced ESCC cells as compared to those injected with control shRNA-transfected ESCC cells. These findings show that the LOC146880/miR-328-5p/FSCN1/MAPK axis regulates ESCC progression in vitro and in vivo. LOC146880 is thus a promising prognostic biomarker and potential therapeutic target in ESCC.

Multi-Omics Analysis of Brain Metastasis Outcomes Following Craniotomy

Background

The incidence of brain metastasis continues to increase as therapeutic strategies have improved for a number of solid tumors. The presence of brain metastasis is associated with worse prognosis but it is unclear if distinctive biomarkers can separate patients at risk for CNS related death.

Methods

We executed a single institution retrospective collection of brain metastasis from patients who were diagnosed with lung, breast, and other primary tumors. The brain metastatic samples were sent for RNA sequencing, proteomic and metabolomic analysis of brain metastasis. The primary outcome was distant brain failure after definitive therapies that included craniotomy resection and radiation to surgical bed. Novel prognostic subtypes were discovered using transcriptomic data and sparse non-negative matrix factorization.

Results

We discovered two molecular subtypes showing statistically significant differential prognosis irrespective of tumor subtype. The median survival time of the good and the poor prognostic subtypes were 7.89 and 42.27 months, respectively. Further integrated characterization and analysis of these two distinctive prognostic subtypes using transcriptomic, proteomic, and metabolomic molecular profiles of patients identified key pathways and metabolites. The analysis suggested that immune microenvironment landscape as well as proliferation and migration signaling pathways may be responsible to the observed survival difference.

Conclusion

A multi-omics approach to characterization of brain metastasis provides an opportunity to identify clinically impactful biomarkers and associated prognostic subtypes and generate provocative integrative understanding of disease.

E2F1-mediated repression of WNT5A expression promotes brain metastasis dependent on the ERK1/2 pathway in EGFR-mutant non-small cell lung cancer

Brain metastasis (BM) is associated with poor prognosis in patients with advanced non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) mutation reportedly enhances the development of BM. However, the exact mechanism of how EGFR-mutant NSCLC contributes to BM remains unknown. Herein, we found the protein WNT5A, was significantly downregulated in BM tissues and EGFR-mutant samples. In addition, the overexpression of WNT5A inhibited the growth, migration, and invasion of EGFR-mutant cells in vitro and retarded tumor growth and metastasis in vivo compared with the EGFR wide-type cells. We demonstrated a molecular mechanism whereby WNT5A be negatively regulated by transcription factor E2F1, and ERK1/2 inhibitor (U0126) suppressed E2F1's regulation of WNT5A expression in EGFR-mutant cells. Furthermore, WNT5A inhibited β-catenin activity and the transcriptional levels of its downstream genes in cancer progression. Our research revealed the role of WNT5A in NSCLC BM with EGFR mutation, and proved that E2F1-mediated repression of WNT5A was dependent on the ERK1/2 pathway, supporting the notion that targeting the ERK1/2-E2F1-WNT5A pathway could be an effective strategy for treating BM in EGFR-mutant NSCLC.

Hypoxic bone marrow mesenchymal cell-extracellular vesicles containing miR-328-3p promote lung cancer progression via the NF2-mediated Hippo axis

Lung cancer is the most aggressive tumour afflicting patients on a global scale. Extracellular vesicle (EV)-delivered microRNAs (miRs) have been reported to play critical roles in cancer development. The current study aimed to investigate the role of hypoxic bone marrow mesenchymal cell (BMSC)-derived EVs containing miR-328-3p in lung cancer. miR-328-3p expression was determined in a set of lung cancer tissues by RT-qPCR. BMSCs were infected with lentivirus-mediated miR-328-3p knock-down and then cultured in normoxic or hypoxic conditions, followed by isolation of EVs. Following ectopic expression and depletion experiments in lung cancer cells, the biological functions of miR-328-3p were analysed using CCK-8 assay, flow cytometry and Transwell assay. Xenograft in nude mice was performed to test the in vivo effects of miR-328-3p delivered by hypoxic BMSC-derived EVs on tumour growth of lung cancer. Finally, the expression of circulating miR-328-3p was detected in the serum of lung cancer patients. miR-328-3p was highly expressed in EVs derived from hypoxic BMSCs. miR-328-3p was delivered to lung cancer cells by hypoxic BMSC-derived EVs, thereby promoting lung cancer cell proliferation, invasion, migration and epithelial-mesenchymal transition. miR-328-3p targeted NF2 to inactivate the Hippo pathway. Moreover, EV-delivered miR-328-3p increased tumour growth in vivo. Additionally, circulating miR-328-3p was bioactive in the serum of lung cancer patients. Taken together, our results demonstrated that hypoxic BMSC-derived EVs could deliver miR-328-3p to lung cancer cells and that miR-328-3p targets the NF2 gene, thereby inhibiting the Hippo pathway to ultimately promote the occurrence and progression of lung cancer.

Therapeutically Significant MicroRNAs in Primary and Metastatic Brain Malignancies

Simple Summary

The overall survival of brain cancer patients remains grim, with conventional therapies such as chemotherapy and radiotherapy only providing marginal benefits to patient survival. Cancers are complex, with multiple pathways being dysregulated simultaneously. Non-coding RNAs such as microRNA (miRNAs) are gaining importance due to their potential in regulating a variety of targets implicated in the pathology of cancers. This could be leveraged for the development of targeted and personalized therapies for cancers. Since miRNAs can upregulate and/or downregulate proteins, this review aims to understand the role of these miRNAs in primary and metastatic brain cancers. Here, we discuss the regulatory mechanisms of ten miRNAs that are highly dysregulated in glioblastoma and metastatic brain tumors. This will enable researchers to develop miRNA-based targeted cancer therapies and identify potential prognostic biomarkers.

Abstract

Brain cancer is one among the rare cancers with high mortality rate that affects both children and adults. The most aggressive form of primary brain tumor is glioblastoma. Secondary brain tumors most commonly metastasize from primary cancers of lung, breast, or melanoma. The five-year survival of primary and secondary brain tumors is 34% and 2.4%, respectively. Owing to poor prognosis, tumor heterogeneity, increased tumor relapse, and resistance to therapies, brain cancers have high mortality and poor survival rates compared to other cancers. Early diagnosis, effective targeted treatments, and improved prognosis have the potential to increase the survival rate of patients with primary and secondary brain malignancies. MicroRNAs (miRNAs) are short noncoding RNAs of approximately 18–22 nucleotides that play a significant role in the regulation of multiple genes. With growing interest in the development of miRNA-based therapeutics, it is crucial to understand the differential role of these miRNAs in the given cancer scenario. This review focuses on the differential expression of ten miRNAs (miR-145, miR-31, miR-451, miR-19a, miR-143, miR-125b, miR-328, miR-210, miR-146a, and miR-126) in glioblastoma and brain metastasis. These miRNAs are highly dysregulated in both primary and metastatic brain tumors, which necessitates a better understanding of their role in these cancers. In the context of the tumor microenvironment and the expression of different genes, these miRNAs possess both oncogenic and/or tumor-suppressive roles within the same cancer.

Circular RNA circSATB2 promotes progression of non-small cell lung cancer cells

BACKGROUND

Lung cancer has high morbidity and mortality worldwide with non-small cell lung cancer (NSCLC) accounting for 85% of the cases. Therapies for lung cancer have relatively poor outcomes and further improvements are required. Circular RNAs have been reported to participate in the occurrence and progression of cancer. Information on the functions and mechanism of circRNAs in lung cancer is limited and needs more exploration.

METHODS

We detected expression of genes and proteins by qPCR and western blot. Function of circSATB2 was investigated using RNA interference and overexpression assays. Location of circSATB2 was assessed by fluorescence in situ hybridization (FISH). Interaction of circSATB2, miR-326 and FSCN1 was confirmed by dual-luciferase reporter assay.

RESULTS

Data from the investigation showed that circSATB2 was highly expressed in NSCLC cells and tissues. circSATB2 positively regulated fascin homolog 1, actin-bundling protein 1 (FSCN1) expression via miR-326 in lung cancer cells. Furthermore, circSATB2 can be transferred by exosomes and promote the proliferation, migration and invasion of NSCLC cells, as well as induce abnormal proliferation in normal human bronchial epithelial cells. Also, circSATB2 was highly expressed in serumal exosomes from lung cancer patients with high sensitivity and specificity for clinical detection and was related to lung cancer metastasis.

CONCLUSIONS

circSATB2 participated in the progression of NSCLC and was differentially expressed in lung cancer tissue and serumal exosomes. circSATB2 may be potential biomarker for the diagnosis of NSCLC.

Long Noncoding RNA DIO3OS Hinders Cell Malignant Behaviors of Hepatocellular Carcinoma Cells Through the microRNA-328/Hhip Axis

Background

The decline of a long non-coding RNA (lncRNA) DIO3OS was implicated in a plethora of cancers, while the relevance in hepatocellular carcinoma (HCC) has not been mentioned. Accordingly, we set to determine the functional role of DIO3OS and the molecular mechanism in HCC progression.

Materials and Methods

The differentially expressed lncRNAs, mRNAs, and microRNAs (miRNAs) were obtained through the datasets GSE101728 and GES57555. Afterwards, DIO3OS was enhanced in HCC cells to examine the behavior changes. Subcellular localization of DIO3OS was determined through website prediction and experimental validation. The expression of Hedgehog (Hh) signaling pathway-related genes was detected. The effects of DIO3OS overexpression on tumor growth were evaluated as well.

Results

DIO3OS was lower in HCC tissues and cells, while upregulation of DIO3OS repressed malignant biological behavior both in vitro and in vivo. DIO3OS, localized in the cytoplasm, inhibited the occurrence of HCC by disrupting the Hh pathway by sponging miR-328 to mediate Hh interacting protein (Hhip).

Conclusion

All in all, the obtained data suggested that DIO3OS interacted with Hhip-dependent Hh signaling pathway to inhibit HCC progression through binding to miR-328, which may be a potent therapeutic target for HCC.

A 5-microRNA signature identified from serum microRNA profiling predicts survival in patients with advanced stage non-small cell lung cancer

Circulating microRNAs (miRNAs) are potential biomarkers for cancer diagnosis, screening and prognosis. This study aimed to identify serum miRNAs as predictors of survival in patients with advanced non-small cell lung cancer (NSCLC). We profiled serum miRNAs in a pilot set of four patients with good survival (>24 months) and four patients with poor survival (<6 months). We selected 140 stably detectable miRNAs and 42 miRNAs reported in literature for further analysis. Expression of these 182 miRNAs was measured using high-throughput polymerase chain reaction assay, and their association with 3-year survival in the discovery (n = 345) and validation (n = 177) cohorts was assessed. Five serum miRNAs (miR-191, miR-28-3p, miR-145, miR-328 and miR-18a) were significantly associated with 3-year overall survival in both cohorts. A combined 5-miRNA risk score was created to assess the cumulative impact of these miRNAs on risk of death. Quartile analysis of the risk score showed significant association with 3-year death risk, with a 4.6-, 6.8- and 9.3-month reduction in median survival time for the second, third and fourth quartiles, respectively. Survival tree analysis also identified distinct risk groups with different 3-year survival durations. Data from The Cancer Genome Atlas revealed all five miRNAs were differentially expressed (P < 0.0001) in paired tumor and normal tissues. Pathway analysis indicated that target genes of these five miRNAs were mainly enriched in inflammatory/immune response pathways and pathways implicated in resistance to chemoradiotherapy and/or targeted therapy. Our results suggested that the 5-miRNA signature could serve as a prognostic predictor in patients with advanced NSCLC.

Tumor microenvironment differences between primary tumor and brain metastases

The present review aimed to discuss contemporary scientific literature involving differences between the tumor microenvironment (TME) in melanoma, lung cancer, and breast cancer in their primary site and TME in brain metastases (BM). TME plays a fundamental role in the behavior of cancer. In the process of carcinogenesis, cells such as fibroblasts, macrophages, endothelial cells, natural killer cells, and other cells can perpetuate and progress carcinogenesis via the secretion of molecules. Oxygen concentration, growth factors, and receptors in TME initiate angiogenesis and are examples of the importance of microenvironmental conditions in the performance of neoplastic cells. The most frequent malignant brain tumors are metastatic in origin and primarily originate from lung cancer, breast cancer, and melanoma. Metastatic cancer cells have to adhere to and penetrate the blood-brain barrier (BBB). After traversing BBB, these cells have to survive by producing various cytokines, chemokines, and mediators to modify their new TME. The microenvironment of these metastases is currently being studied owing to the discovery of new therapeutic targets. In these three types of tumors, treatment is more effective in the primary tumor than in BM due to several factors, including BBB. Understanding the differences in the characteristics of the microenvironment surrounding the primary tumor and their respective metastasis might help improve strategies to comprehend cancer.

MicroRNA-330-3p promotes brain metastasis and epithelial-mesenchymal transition via GRIA3 in non-small cell lung cancer

Brain metastasis (BM) is associated with poor prognosis in patients with non-small cell lung cancer (NSCLC). We sought to identify microRNAs (miRNAs) that could serve as biomarkers to differentiate NSCLC patients with and without BM. Logistic regression was conducted with 122 NSCLC patients (60 without BM, 62 with BM) to assess the association between miRNAs and BM. We confirmed several risk factors for BM and revealed that serum miR-330-3p levels are higher in NSCLC patients with BM than that without BM. Overexpression of miR-330-3p promoted proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of NSCLC cells in vitro and NSCLC tumorigenesis in vivo. Knocking down miR-330-3p suppressed this metastatic phenotype. We identified putative miR-330-3p target genes by comparing mRNA microarray analysis data from A549 cells after miR-330-3p knockdown with candidate miR-330-3p target genes predicted by public bioinformatic tools and luciferase reporter assays. We found that GRIA3 is a target of miR-330-3p and that miR-330-3p stimulates EMT progress by mediating GRIA3-TGF-β1 interaction. Our results provide novel insight into the role of miR-330-3p in NSCLC metastasis, and suggest miR-330-3p may be a useful biomarker for identifying NSCLC with metastatic potential.

microRNA-328 in exosomes derived from M2 macrophages exerts a promotive effect on the progression of pulmonary fibrosis via FAM13A in a rat model

Currently, exosome-enclosed microRNAs (miRs) in exhaled breath have potential for biomarker discovery in patients with pulmonary diseases. This study was performed to investigate the roles of M2 macrophage-derived exosomes expressing miR-328 in pulmonary fibrosis (PF). Microarray-based analysis was used to screen differentially expressed genes (DEGs) and regulatory miRs in PF. The miR-target relationship between FAM13A and miR-328 was confirmed. The expression of FAM13A and miR-328 was measured in PF rats, and gain- and loss-of-function assays were conducted to determine the regulatory effects of FAM13A and miR-328 on PF. In addition, exosomes derived from M2 macrophages were isolated and then cocultured with pulmonary interstitial fibroblasts to identify the role of these exosomes in PF. Furthermore, the effects of M2 macrophage-derived exosomes overexpressing miR-328 on pulmonary fibroblast proliferation and the progression of PF were assessed in vivo. miR-328 might perform a vital function in PF by regulating FAM13A. FAM13A expression was downregulated while miR-328 expression was upregulated in rats with PF, and a miR-target relationship between miR-328 and FAM13A was observed. Additionally, miR-328 overexpression and FAM13A silencing each were suggested to promote pulmonary interstitial fibroblast proliferation and the expression of Collagen 1A, Collagen 3A and α-SMA. Then, in vitro experiments demonstrated that M2 macrophage-derived exosomes overexpressing miR-328 contributed to enhanced pulmonary interstitial fibroblast proliferation and promoted PF. Furthermore, in vivo experiments confirmed the promotive effects of M2 macrophage-derived exosomes overexpressing miR-328 on the progression of PF. Collectively, the results showed that M2 macrophage-derived exosomes overexpressing miR-328 aggravate PF through the regulation of FAM13A.

Studies in rats suggest that microRNAs, small molecules of ribonucleic acid, released by macrophage cells of the immune system can promote pulmonary fibrosis (PF), the formation of scar tissue in lungs. Gao-Feng Zhao, Li-Hua Xing and colleagues at The First Affiliated Hospital of Zhengzhou University in China investigated the role of microRNAs in rats with a form of PF that serves as a model for the disease in humans. Their findings confirm that specific microRNAs released in tiny membrane-bound sacs called exosomes interact with and inhibit a gene whose activity is known to be disrupted in PF. The protein encoded by this gene mediates crucial molecular signaling events in lung cells. Developing drugs that interfere with the activity of the microRNAs is a potential new treatment approach for PF.

lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE) Promotes Proliferation and Inhibits Apoptosis in Non-Small Cell Lung Cancer Cells by Regulating the miR-641/CDK6 Axis

BACKGROUND The lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE) gene has been reported as a potential oncogene in NSCLC. Nevertheless, the molecular mechanism of CRNDE in NSCLC progression remains largely unknown. MATERIAL AND METHODS qRT-PCR assay was performed to detect the expression levels of CRNDE, miR-641, and cyclin-dependent kinase 6 (CDK6) in NSCLC. Western blot assay was employed to assess CDK6 protein level in treated NSCLC cells. si-CRNDE#1, si-CRNDE#2, miR-641 mimics, miR-641 inhibitors, or Vector-CDK6 were transfected into NSCLC cells to change the expression levels of CRNDE, miR-641, or CDK6. Dual-luciferase reporter assay was performed to validate the direct interrelated miRNA of CRNDE and the potential target of miR-641. MTT and flow cytometry assays were performed to assess the capacities of cell proliferation and apoptosis, respectively. RESULTS CRNDE level was upregulated in NSCLC, and its knockdown suppressed NSCLC cells proliferation and enhanced apoptosis, whereas miR-641 antagonized the regulatory effect of CRNDE knockdown by directly binding to CRNDE. Moreover, CDK6 was a target of miR-641 and miR-641 exerted anti-proliferation and pro-apoptosis effects through CDK6. CONCLUSIONS CRNDE promoted proliferation and inhibited apoptosis of NSCLC cells at least in part by regulating the miR-641/CDK6 axis, suggesting that CRNDE is a potential therapeutic target for NSCLC treatment.

miR-608 and miR-4513 significantly contribute to the prognosis of lung adenocarcinoma treated with EGFR-TKIs

Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptors (EGFR) significantly prolong the survival of lung adenocarcinoma patients with sensitizing EGFR mutations. Unfortunately, 10-30% patients do not show objective responses to EGFR-TKIs, and undergo rapid disease progression during the EGFR-TKIs therapy. Single nucleotide polymorphisms (SNPs) in mature microRNA (miRNA) sequences may influence target site interactions and modulate downstream pathways, such as the EGFR pathway. For this reason, we hypothesized that miRNA SNPs may impact the prognosis of lung adenocarcinoma patients after EGFR-TKI treatment. By systematically screening of the miRbase and the 1000 genomes project databases, we successfully identified five mature miRNA SNPs. Genotypes were determined in two independent cohorts (Hubei and Shandong cohorts) that include 319 EGFR-TKI treated stage IIIB/IV patients. The impact of miR-608 and miR-4513 on the drug sensitivity of gefitinib was examined in lung adenocarcinoma cells. miR-608 rs4919510 or miR-4513 rs2168518 significantly contributed to the progression-free survival (PFS) in the Hubei cohort (hazard ratio [HR] = 0.63, confidence interval [CI] = 0.49-0.81, P = 3.0 × 10^-4 or HR = 0.46, 95% CI = 0.31-0.67, P = 8.0 × 10^-5). These observations were further validated in the Shandong cohort (P = 0.005 or P = 0.001). Similarly, the miR-608 rs4919510 CC genotype or the miR-4513 rs2168518 GA genotype was significantly associated with decreased death risk after gefitinib treatment, compared with the rs4919510 GG genotype (Hubei cohort: P = 5.0 × 10^-4; Shandong cohort: P = 0.004) or the rs2168518 GG genotype (P = 4.9 × 10^-5; P = 0.002). Consistently, miR-608 significantly increased the anti-proliferation effect of gefitinib in both lung adenocarcinoma PC9 and H1299 cells, whereas miR-4513 increased cells' resistance to gefitinib. Our findings suggest that miR-608 and miR-4513 SNPs are independent candidate biomarkers to predict lung adenocarcinoma patients' survival after EGFR-TKIs treatment. These miRNAs and polymorphisms provide clinical potential in patient-tailored treatment decision-making.

Elevated expression of microRNA-328-3p suppresses aggressive malignant behaviors via targeting matrix metalloprotease 16 in osteosarcoma

Background

A previous study indicated that microRNA(miR)-328-3p upregulation might be critical for resveratrol-mediated suppression of metastatic ability in human osteosarcoma, implying its potential role in this malignancy. However, the clinical significance and the biological functions of miR-328-3p in osteosarcoma remain unclear.

Methods

miR-328-3p expression in 88 pairs of osteosarcoma and matched non-cancerous bone tissues were detected by quantitative real-time PCR. Then, the associations of miR-328-3p expression with various clinicopathological features of osteosarcoma patients were statistically analyzed. Cell Counting Kit-8 and scratch-wound healing were performed to evaluate roles of miR-328-3p in human osteosarcoma cells. After that, luciferase reporter assay, western blot analysis and rescue assay were applied to determine the underlying molecular mechanisms of miR-328-3p in osteosarcoma cells.

Results

miR-328-3p expression in osteosarcoma tissues was significantly lower than those in non-cancerous bone tissues (P<0.001). miR-328-3p downregulation was significantly associated with advanced surgical stage, positive metastasis and recurrence (all P<0.05). Functionally, enforced expression of miR-328-3p efficiently suppressed cell proliferation and migration in vitro. Moreover, matrix metalloprotease 16 (MMP16) was identified as a direct target of miR-328-3p in osteosarcoma cells. Notably, MMP16 overexpression partially reversed the miR-328-3p-inhibited cell proliferation and migration of osteosarcoma cells.

Conclusions

Our data indicated that the aberrant expression of miR-328-3p may play a crucial role in malignant progression of human osteosarcoma. More importantly, miR-328-3p may function as a tumor suppressor inhibiting osteosarcoma cell proliferation and migration partially mediated by regulating of MMP16.

Identification of CD37, cystatin A, and IL-23A gene expression in association with brain metastasis: analysis of a prospective trial

PURPOSE/OBJECTIVES

We aimed to assess the predictive value of a lung cancer gene panel for the development of brain metastases.

MATERIALS/METHODS

Between 2011 and 2015, 102 patients with lung cancer were prospectively enrolled in a clinical trial in which a diagnostic fine-needle aspirate was obtained. Gene expression was conducted on all samples that rendered a diagnosis of non-small cell lung cancer (NSCLC). Subsequent retrospective analysis of brain metastases-related outcomes was performed by reviewing patient electronic medical records. A competing risk multivariable regression was performed to estimate the adjusted hazard ratio for the development of brain metastases and non-brain metastases from NSCLC.

RESULTS

A total of 49 of 102 patients had died by the last follow-up. Median time of follow-up was 13 months (range 0.23-67 months). A total of 17 patients developed brain metastases. Median survival time after diagnosis of brain metastases was 3.58 months (95% confidence interval (CI) 2.17, not available). A total of 30 patients developed metastases without any evidence of brain metastases until the time of death or last follow-up. Competing risk analysis identified three genes that were downregulated differentially in the patients with brain metastases versus non-brain metastatic disease: CD37 (0.017), cystatin A (0.022), and IL-23A (0.027). Other factors associated with brain metastases include: stage T ( P ⩽ 8.3e^-6) and stage N ( P= 6.8e^-4).

CONCLUSIONS

We have identified three genes, CD37, cystatin A, and IL-23A, for which downregulation of gene expression was associated with a greater propensity for developing brain metastases. Validation of these biomarkers could have implications on surveillance patterns in patients with brain metastases from NSCLC.

MicroRNA in Lung Cancer Metastasis

Tumor metastasis is a hallmark of cancer, with distant metastasis frequently developing in lung cancer, even at initial diagnosis, resulting in poor prognosis and high mortality. However, available biomarkers cannot reliably predict cancer spreading sites. The metastatic cascade involves highly complicated processes including invasion, migration, angiogenesis, and epithelial-to-mesenchymal transition that are tightly controlled by various genetic expression modalities along with interaction between cancer cells and the extracellular matrix. In particular, microRNAs (miRNAs), a group of small non-coding RNAs, can influence the transcriptional and post-transcriptional processes, with dysregulation of miRNA expression contributing to the regulation of cancer metastasis. Nevertheless, although miRNA-targeted therapy is widely studied in vitro and in vivo, this strategy currently affords limited feasibility and a few miRNA-targeted therapies for lung cancer have entered into clinical trials to date. Advances in understanding the molecular mechanism of metastasis will thus provide additional potential targets for lung cancer treatment. This review discusses the current research related to the role of miRNAs in lung cancer invasion and metastasis, with a particular focus on the different metastatic lesions and potential miRNA-targeted treatments for lung cancer with the expectation that further exploration of miRNA-targeted therapy may establish a new spectrum of lung cancer treatments.

A Comprehensive Meta-Analysis of Association between EGFR Mutation Status and Brain Metastases in NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation have different clinicopathological characteristics compared with EGFR wild type NSCLC. A growing number of studies focused on the relevance between EGFR mutation status and brain metastases (BM) in NSCLC, but it remains controversial. Therefore, this study performed a comprehensive meta-analysis to untangle this issue. Several electronic databases including Pubmed, Embase, Web of science and Cochrane database were thoroughly searched. The odds ratio (OR) with 95% confidence interval (95%CI) was pooled to evaluate the relevance. Meta-regression analysis and subgroup analysis were conducted according to the heterogeneity. A total of 26 studies were identified finally in this meta-analysis. The overall OR was 1.58 (95%CI: 1.36-1.84), which indicated that EGFR mutation had a positive association with BM of NSCLC. The subgroup analysis resulted from eleven studies with lung adenocarcinoma revealed a higher possibility of BM in NSCLC with EGFR mutation compared with EGFR wild (p < 0.05). There was no significant difference in the risk of BM between NSCLC EGFR exon 19 mutation and exon 21 point mutation (p = 0.23). This meta-analysis suggests that EGFR mutation can be a risk factor for BM in NSCLC.

Molecular predictors of brain metastasis-related microRNAs in lung adenocarcinoma

Brain metastasis (BM) is a major complication of lung adenocarcinoma (LAD). An investigation of the pathogenic mechanisms of BM, as well as the identification of appropriate molecular markers, is necessary. The aim of this study was to determine the expression patterns of microRNAs (miRNAs) in LAD with BM, and to investigate the biological role of these miRNAs during tumorigenesis. miRNA array profiles were used to identify BM-associated miRNAs. These miRNAs were independently validated in 155 LAD patients. Several in vivo and in vitro assays were performed to verify the effects of miRNAs on BM. We identified six miRNAs differentially expressed in patients with BM as compared to patients with BM. Of these, miR-4270 and miR-423-3p were further investigated. miR-4270 and miR-423-3p directly targeted MMP19 and P21, respectively, to influence cell viability, migration, and colony formation in vitro. miR-4270 downregulation and miR-423-3p upregulation was associated with an increased risk of BM in LAD patients. Thus, our results suggested that miR-4270 and miR-423-3p might play an important role in BM pathogenesis in LAD patients, and that these miRNAs might be useful prognostic and clinical treatment targets.

Brain metastasis (BM) is a major complication of lung carcinoma. Here, we aimed to identify the key miRNAs involved in BM lung cancer. We first profiled miRNA expression in 32 tissues from NSCLC patients with BM and 55 tissues from NSCLC patients without BM. We independently validated our results in 68 additional tissues from NSCLC patients. Based on our results, we identified a panel of miRNAs that distinguish BM lung adenocarcinomas from non-BM We report here for the first time that either miR-4270 downregulation or miR-423-3p upregulation significantly increased cell proliferation, colony formation, and migration in vitro. miR-4270 and miR-423-3p increased the risk of BM in mouse models by targeting MMP19 and P21, respectively. Our results suggested that miR-4270 and miR-423-3p might be useful markers of BM in lung adenocarcinoma.

MicroRNA-328 ameliorates oxidized low-density lipoprotein-induced endothelial cells injury through targeting HMGB1 in atherosclerosis

Atherosclerosis has been recognized as a chronic inflammatory disease, which can harden the vessel wall and narrow the arteries. MicroRNAs exhibit crucial roles in various diseases including atherosclerosis. However, so far, the role of miR-328 in atherosclerosis remains barely explored. Therefore, our study concentrated on the potential role of miR-328 in vascular endothelial cell injury during atherosclerosis. In our current study, we observed that oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) apoptosis and inhibited cell viability dose-dependently and time-dependently. In addition, indicated dosage of ox-LDL obviously triggered HUVECs inflammation and oxidative stress process. Then, it was found that miR-328 in HUVECs was reduced by ox-LDL. HUVECs apoptosis was greatly repressed and cell survival was significantly upregulated by overexpression of miR-328. Furthermore, mimics of miR-328 rescued cell inflammation and oxidative stress process induced by ox-LDL. Oppositely, inhibitors of miR-328 strongly promoted ox-LDL-induced endothelial cells injury in HUVECs. By using bioinformatics analysis, high-mobility group box-1 (HMGB1) was predicted as a downstream target of miR-328. HMGB1 has been reported to be involved in atherosclerosis development. The correlation between miR-328 and HMGB1 was validated in our current study. Taken these together, it was implied that miR-328 ameliorated ox-LDL-induced endothelial cells injury through targeting HMGB1 in atherosclerosis.

The therapeutic role of inhibition of miR-328 on pulmonary carcinoma induced by chlamydia pneumoniae through targeting histone H2AX

Lung cancer represents a major healthy concern due to high incidence and morality. Increasing evidences showed critical regulatory role of microRNA (miR) in cell growth, differentiation and apoptosis. It has been indicated that the level of miR-328 is abnormally up regulated in lung cancer cell line, which is correlated with cell apoptosis. An in vitro lung cancer model was established through induction of chlamydia pneumonia. Western blot and real-time quantitative PCR were used to measure miR-328 level and its effects on histone H2AX expression. Bioinformatics analysis and luciferase reporter gene assay were to determine if H2AX was the direct target of miR-328. TUNEL assay, AV-PI staining and Caspase-3 activity assay measured the effect of the decrease of miR-328 on lung cancer cell apoptosis at both in vivo and in vitro level. Bioinformatics analysis predicted histone H2AX as the target of miR-328 during the regulation of lung cancer. Both in vivo and in vitro knockdown of miR-328 up-regulated H2AX expression and elevated TUNEL-positive cell number. In vivo down-regulation of miR-328 decreased incidence of lung cancer induced by chlamydia pneumoniae, suppressed tumor volume, increased caspase 3 activity, and facilitated tumor cell apoptosis. Histone protein H2AX serves as the target of miR-328 and participates in lung cancer regulation. Suppression of miR-328 level promotes lung cancer tissue apoptosis, which provides novel target for lung cancer therapy.

miR-330-3p promotes lung cancer cells invasion, migration, and metastasis by directly targeting hSOD2b

Lung cancer is a serious threat to human health. Studies have revealed that human manganese superoxide dismutase (hSOD2) and miRNAs play an essential role in the metastasis process of lung cancer. However, the miRNAs that associated with hSOD2 and involved in metastasis, remain elusive. After databases analysis and dual luciferase reporter validation, we demonstrated that miR-330-3p expression inversely correlated with hSOD2b expression level, and that miR-330-3p directly targeted the 3'untranslated region (3'UTR) of hSOD2b. Furthermore, overexpression of miR-330-3p promoted whereas knockdown of miR-330-3p inhibited invasion/migration and the epithelial-mesenchymal transition (EMT) process of lung cancer cells in vitro. Knockdown of miR-330-3p inhibited metastasis of lung cancer cells in vivo. Moreover, miR-330-3p-mediated enhancement of invasion/migration in 95-D cells could be rescued by over-expression of hSOD2. In conclusion, we demonstrated that miR-330-3p promoted metastasis of lung cancer cells by suppressing hSOD2b expression and unveiled a new clinical application of miR-330-3p in the therapy of lung cancer.

MiR-423-5p in brain metastasis: potential role in diagnostics and molecular biology

During the last several years, a growing number of studies have shown that microRNAs (miRNAs) participate in cancer metastasis. Brain metastasis (BM) is a frequent complication of lung adenocarcinoma (LAD), and the incidence of locally advanced LAD with BM can be as high as 30-50%. This study was performed to identify the miRNA expression patterns of LAD with BM and to determine the biological role that miRNAs play in tumorigenesis. To this end, we conducted microarray and quantitative PCR analyses to evaluate BM-related miRNAs independently validated from a total of 155 patients with LAD. A series of in vivo and in vitro assays were also conducted to verify the impact of miRNAs on BM. We found significantly increased expression of miR-423-5p, and BM was predicted in non-small cell lung cancer when compared to LAD without BM. We next examined the function of miR-423-5p and discovered that it significantly promoted colony formation, cell motility, migration, and invasion in vitro. We computationally and experimentally confirmed that metastasis suppressor 1 (MTSS1) was a direct miR-423-5p target. Through a combination of image, histological, and molecular analyses, we found that miR-423-5p overexpression significantly increased tumor burden, local invasion, and distant BM. The level of MTSS1 expression was inversely correlated with miR-423-5p upregulation in the LAD specimens and was associated with survival of patients with BM. MiR-423-5p promoted BM in LAD and inhibited MTSS1 expression. Together, these results show that MiR-423-5p has the potential to be a marker of BM and/or a therapeutic target in LAD.

miRNA‑328 overexpression confers cisplatin resistance in non‑small cell lung cancer via targeting of PTEN

Chemotherapy resistance, the molecular mechanism of which is complex and has not been fully understood, poses a major challenge in the treatment of patients with non‑small cell lung cancer (NSCLC). The dysregulation of microRNAs (miRs) has been reported to serve a pivotal role in the development of cancer and drug resistance. In the present study, reverse transcription‑quantitative polymerase chain reaction analysis revealed a significant increase in miR‑328 and a significant decrease in phosphatase and tensin homolog (PTEN) mRNA expression levels within tumor tissues from patients with cisplatin‑resistant NSCLC compared with those of cisplatin‑sensitive NSCLC patients. In addition, there was a negative correlation between PTEN mRNA and the miR‑328 expression levels. In addition, higher miR‑328 expression levels, and lower PTEN mRNA and protein expression levels, were detected in cisplatin‑resistant A549 (A549rCDDP) cells when compared with in their parental cells. A549rCDDP cells demonstrated significantly higher cell viability compared with A549 cells following treatment with all concentrations of cisplatin tested (2, 4, 6 and 8 µM). Additionally, transfection of miR‑328 inhibitor significantly increased PTEN mRNA and protein expression levels. Furthermore, the present study predicted and confirmed PTEN, a well‑known tumor suppressor, as a direct target of miR‑328 in NSCLC cells via the online tool MiRanda and a dual luciferase assay, respectively. Cell viability assay and flow cytometry analysis demonstrated that inhibition of miR‑328 also induced cellular apoptosis and decreased cell proliferation in A549rCDDP cells treated with cisplatin. In conclusion, these results suggested that abnormal expression of miR‑328 may contribute to cisplatin resistance in NSCLC, and may be considered to be a novel therapeutic target and indicator for the treatment and prognosis of patients with NSCLC treated with cisplatin‑based chemotherapy.

MicroRNA in lung cancer: role, mechanisms, pathways and therapeutic relevance

Lung cancer is the cardinal cause of cancer-related deaths with restricted recourse of therapy throughout the world. Clinical success of therapies is not very promising due to - late diagnosis, limited therapeutic tools, relapse and the development of drug resistance. Recently, small ∼20-24 nucleotides molecules called microRNAs (miRNAs) have come into the limelight as they play outstanding role in the process of tumorigenesis by regulating cell cycle, metastasis, angiogenesis, metabolism and apoptosis. miRNAs essentially regulate gene expression via post-transcriptional regulation of mRNA. Nevertheless, few studies have conceded the role of miRNAs in activation of gene expression. A large body of data generated by numerous studies is suggestive of their tumor-suppressing, oncogenic, diagnostic and prognostic biomarker roles in lung cancer. They have also been implicated in regulating cancer cell metabolism and resistance or sensitivity towards chemotherapy and radiotherapy. Further, miRNAs have also been convoluted in regulation of immune checkpoints - Programmed death 1 (PD-1) and its ligand (PD-L1). These molecules play a significant role in tumor immune escape leading to the generation of a microenvironment favouring tumor growth and progression. Therefore, it is imperative to explore the expression of miRNA and understand its relevance in lung cancer and development of anti-cancer strategies (anti - miRs, miR mimics and micro RNA sponges). In view of the above, the role of miRNA in lung cancer has been dissected and the associated mechanisms and pathways are discussed in this review.