MicroRNA-195 inhibits proliferation, invasion and metastasis in breast cancer cells by targeting FASN, HMGCR, ACACA and CYP27B1

Proteomic Analysis Reveals the Effect of Trichostatin A and Bone Marrow-Derived Dendritic Cells on the Fatty Acid Metabolism of NIH3T3 Cells under Oxygen-Glucose Deprivation Conditions

Fibroblasts mediate acute wound healing and long-term tissue remodeling with scarring after tissue injury. Following myocardial infarction (MI), necrotized cardiomyocytes become replaced by secreted extracellular matrix proteins produced by fibroblasts. Dendritic cells (DCs) can migrate from the bone marrow to the infarct areas and infarct border areas to mediate collagen accumulation after MI. Trichostatin A (TSA) is known to regulate apoptosis and proliferation in fibroblasts and affect the functions of DCs under oxygen-glucose deprivation (OGD) conditions. In this study, we used label-free quantitative proteomics to investigate the effects of TSA and bone marrow-derived dendritic cells (BMDCs) on NIH3T3 fibroblasts under OGD conditions. The results showed that the fatty acid degradation pathway was significantly upregulated in NIH3T3 cells under OGD conditions and that the fatty acid synthesis pathway was significantly downregulated in NIH3T3 cells treated with conditioned media (CM) from BMDCs treated with TSA under OGD conditions [BMDCs-CM(TSA)]. In addition, BMDCs-CM(TSA) significantly decreased the levels of triglycerides and free fatty acids and mediated fatty acid metabolism-related proteins in NIH3T3 cells under OGD conditions. In summary, this proteomics analysis showed that TSA and BMDCs affect fatty acid metabolism in NIH3T3 cells under OGD conditions.

Functional genetic variant of HSD17B12 in the fatty acid biosynthesis pathway predicts the outcome of colorectal cancer

Fatty acids are involved in the development and progression of colorectal cancer (CRC). However, genetic effects of fatty acid biosynthesis pathway on CRC outcome are unclear. Cox regression model was used to evaluate genetic effects on CRC overall survival (OS) and progression‐free survival (PFS), accompanied by calculating hazard ratios (HRs) and confidence intervals (CIs). Differential expression analysis, expression quantitative trait loci analysis, dual‐luciferase reporter assay and chromatin immunoprecipitation assay were performed to explore the genetically biological mechanism. The rs10838164 C>T in HSD17B12 was significantly associated with an increased risk of death and progression of CRC (OS, HR = 2.12, 95% CI = 1.40‐3.22, P = 4.03 × 10⁻⁴; PFS, HR = 1.64, 95% CI = 1.11‐2.44, P = 1.35 × 10⁻²), of which T allele could increase HSD17B12 expression (P = 1.78 × 10⁻¹¹). Subsequently, the functional experiments indicated that rs10838164 T allele could not only enhance the binding affinity of transcription factor YY1 to HSD17B12 region harbouring rs10838164 but also promote the transcriptional activity of HSD17B12, which was significantly up‐regulated in colorectal tumour tissues. Our findings suggest that genetic variants in fatty acid biosynthesis pathway play an important role in CRC outcome.

Non-Coding and Regulatory RNAs as Epigenetic Remodelers of Fatty Acid Homeostasis in Cancer

Cancer cells commonly display metabolic fluctuations. Together with the Warburg effect and the increased glutaminolysis, alterations in lipid metabolism homeostasis have been recognized as a hallmark of cancer. Highly proliferative cancer cells upregulate de novo synthesis of fatty acids (FAs) which are required to support tumor progression by exerting multiple roles including structural cell membrane composition, regulators of the intracellular redox homeostasis, ATP synthesis, intracellular cell signaling molecules, and extracellular mediators of the tumor microenvironment. Epigenetic modifications have been shown to play a crucial role in human development, but also in the initiation and progression of complex diseases. The study of epigenetic processes could help to design new integral strategies for the prevention and treatment of metabolic disorders including cancer. Herein, we first describe the main altered intracellular fatty acid processes to support cancer initiation and progression. Next, we focus on the most important regulatory and non-coding RNAs (small noncoding RNA-sncRNAs-long non-coding RNAs-lncRNAs-and other regulatory RNAs) which may target the altered fatty acids pathway in cancer.

Platelet-derived extracellular vesicles regulate cell cycle progression and cell migration in breast cancer cells

Platelets have been extensively implicated in the progression of cancer and platelet-derived extracellular vesicles (PEVs) are gaining growing attention as potential mediators of the platelet-cancer interplay. PEVs are shed from platelet membrane in response to extracellular stimuli and carry important biological signals for intercellular communication. In this study we demonstrate that PEVs specifically bind to different breast cancer cells and elicit cell-specific functional responses. PEVs were massively internalized by the metastatic cell lines MDA-MB-231 and SKBR3 and the ductal carcinoma cell line BT474, but not by the MCF-7 cell line. In SKBR3 cells, PEVs decreased mitochondrial dehydrogenase activities and altered cell cycle progression without affecting cell viability. Conversely, PEVs potently stimulated migration and invasion of MDA-MB-231, without affecting the distribution in the different phases of the cell cycle. In all the analyzed breast cancer cells, PEVs triggered a sustained increase of intracellular Ca²⁺, but only in MDA-MB-231 cells, this was associated to the stimulation of selected signaling proteins implicated in migration, including p38MAPK and myosin light chain. Importantly, inhibition of myosin light chain phosphorylation by a Rho kinase inhibitor prevented PEVs-stimulated migration of MDA-MB-231 cells. Our results demonstrate that PEVs are versatile regulators of cancer cell behavior and elicit a variety of different responses depending on the specific breast cancer cell subtype.

MicroRNA-195 controls MICU1 expression and tumor growth in ovarian cancer

MICU1 is a mitochondrial inner membrane protein that inhibits mitochondrial calcium entry; elevated MICU1 expression is characteristic of many cancers, including ovarian cancer. MICU1 induces both glycolysis and chemoresistance and is associated with poor clinical outcomes. However, there are currently no available interventions to normalize aberrant MICU1 expression. Here, we demonstrate that microRNA-195-5p (miR-195) directly targets the 3' UTR of the MICU1 mRNA and represses MICU1 expression. Additionally, miR-195 is under-expressed in ovarian cancer cell lines, and restoring miR-195 expression reestablishes native MICU1 levels and the associated phenotypes. Stable expression of miR-195 in a human xenograft model of ovarian cancer significantly reduces tumor growth, increases tumor doubling times, and enhances overall survival. In conclusion, miR-195 controls MICU1 levels in ovarian cancer and could be exploited to normalize aberrant MICU1 expression, thus reversing both glycolysis and chemoresistance and consequently improving patient outcomes.

Metabolic Constrains Rule Metastasis Progression

Metastasis formation accounts for the majority of tumor-associated deaths and consists of different steps, each of them being characterized by a distinctive adaptive phenotype of the cancer cells. Metabolic reprogramming represents one of the main adaptive phenotypes exploited by cancer cells during all the main steps of tumor and metastatic progression. In particular, the metabolism of cancer cells evolves profoundly through all the main phases of metastasis formation, namely the metastatic dissemination, the metastatic colonization of distant organs, the metastatic dormancy, and ultimately the outgrowth into macroscopic lesions. However, the metabolic reprogramming of metastasizing cancer cells has only recently become the subject of intense study. From a clinical point of view, the latter steps of the metastatic process are very important, because patients often undergo surgical removal of the primary tumor when cancer cells have already left the primary tumor site, even though distant metastases are not clinically detectable yet. In this scenario, to precisely elucidate if and how metabolic reprogramming drives acquisition of cancer-specific adaptive phenotypes might pave the way to new therapeutic strategies by combining chemotherapy with metabolic drugs for better cancer eradication. In this review we discuss the latest evidence that claim the importance of metabolic adaptation for cancer progression.

The Regulatory Role of Mitochondrial MicroRNAs (MitomiRs) in Breast Cancer: Translational Implications Present and Future

Simple Summary

Mitochondrial microRNAs (mitomiRs) are an emerging field of study in a wide range of tumours including breast cancer. By targeting mitochondrial, or non-mitochondrial products, mitomiRs are able to regulate the functions of this organelle, thus controlling multiple carcinogenic processes. The knowledge of this system may provide a novel approach for targeted therapies, as potential biomarkers or helping in the diagnosis of such a complex malignancy.

Abstract

Breast cancer is the most prevalent and incident female neoplasm worldwide. Although survival rates have considerably improved, it is still the leading cause of cancer-related mortality in women. MicroRNAs are small non-coding RNA molecules that regulate the posttranscriptional expression of a wide variety of genes. Although it is usually located in the cytoplasm, several studies have detected a regulatory role of microRNAs in other cell compartments such as the nucleus or mitochondrion, known as “mitomiRs”. MitomiRs are essential modulators of mitochondrion tasks and their abnormal expression has been linked to the aetiology of several human diseases related to mitochondrial dysfunction, including breast cancer. This review aims to examine basic knowledge of the role of mitomiRs in breast cancer and discusses their prospects as biomarkers or therapeutic targets.

The emerging role of miRNA clusters in breast cancer progression

Micro RNAs (miRNAs) are small non-coding RNAs that are essential for regulation of gene expression of the target genes. Large number of miRNAs are organized into defined units known as miRNA clusters (MCs). The MCs consist of two or more than two miRNA encoding genes driven by a single promoter, transcribed together in the same orientation, that are not separated from each other by a transcription unit. Aberrant miRNA clusters expression is reported in breast cancer (BC), exhibiting both pro-tumorogenic and anti-tumorigenic role. Altered MCs expression facilitates to breast carcinogenesis by promoting the breast cells to acquire the various hallmarks of the cancer. Since miRNA clusters contain multiple miRNA encoding genes, targeting cluster may be more attractive than targeting individual miRNAs. Besides targeting dysregulated miRNA clusters in BC, studies have focused on the mechanism of action, and its contribution to the progression of the BC. The present review provides a comprehensive overview of dysregulated miRNA clusters and its role in the acquisition of cancer hallmarks in BC. More specifically, we have presented the regulation, differential expression, classification, targets, mechanism of action, and signaling pathways of miRNA clusters in BC. Additionally, we have also discussed the potential utility of the miRNA cluster as a diagnostic and prognostic indicator in BC.

Fatty acid synthase contributes to epithelial-mesenchymal transition and invasion of salivary adenoid cystic carcinoma through PRRX1/Wnt/β-catenin pathway

Fatty acid synthase (FASN) has been shown to be selectively up‐regulated in cancer cells to drive the development of cancer. However, the role and associated mechanism of FASN in regulating the malignant progression of salivary adenoid cystic carcinoma (SACC) still remains unclear. In this study, we demonstrated that FASN inhibition attenuated invasion, metastasis and EMT of SACC cells as well as the expression ofPRRX1, ZEB1, Twist, Slug and Snail, among which the level of PRRX1 changed the most obviously. Overexpression of PRRX1 restored migration and invasion in FASN knockdown cells, indicating that PRRX1 is an important downstream target of FASN signalling. Levels of cyclin D1 and c‐Myc, targets of Wnt/β‐catenin pathway, were significantly decreased by FASN silencing and restored by PRRX1 overexpression. In addition, FASN expression was positively associated with metastasis and poor prognosis of SACC patients as well as with the expression of PRRX1, cyclin D1 and c‐Myc in SACC tissues. Our findings revealed that FASN in SACC progression may induce EMT in a PRRX1/Wnt/β‐catenin dependent manner.

Non-coding RNAs, metabolic stress and adaptive mechanisms in cancer

Metabolic reprogramming in cancer describes the multifaceted alterations in metabolism that contribute to tumorigenesis. Major determinants of metabolic phenotypes are the changes in signalling pathways associated with oncogenic activation together with cues from the tumor microenvironment. Therein, depleted oxygen and nutrient levels elicit metabolic stress, requiring cancer cells to engage adaptive mechanisms. Non-coding RNAs (ncRNAs) act as regulatory elements within metabolic pathways and their widespread dysregulation in cancer contributes to altered metabolic phenotypes. Indeed, ncRNAs are the regulatory accomplices of many prominent effectors of metabolic reprogramming including c-MYC and HIFs that are activated by metabolic stress. By example, this review illustrates the range of ncRNAs mechanisms impacting these effectors throughout their DNA-RNA-protein lifecycle along with presenting the mechanistic roles of ncRNAs in adaptive responses to glucose, glutamine and lipid deprivation. We also discuss the facultative activation of metabolic enzymes by ncRNAs, a phenomenon which may reflect a broad but currently invisible level of metabolic regulation. Finally, the translational challenges associated with ncRNA discoveries are discussed, emphasizing the gaps in knowledge together with importance of understanding the molecular basis of ncRNA regulatory mechanisms.

LINC00202 promotes retinoblastoma progression by regulating cell proliferation, apoptosis, and aerobic glycolysis through miR-204-5p/HMGCR axis

LINC00202 is a newly identified long noncoding RNA (lncRNA) and has been demonstrated to involve in the progression of retinoblastoma (RB). Here, we further explored the role and the underlying molecular mechanism of LINC00202 on RB malignant properties and glycolysis. LINC00202, microRNA (miR)-204-5p, and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) mRNA were detected by a quantitative real-time polymerase chain reaction. Cell proliferation and apoptosis were analyzed using cell counting kit-8 assay and colony formation assay and flow cytometry, respectively. Glucose metabolism was calculated by measuring the extracellular acidification rate (ECRA). Western blot was used to detect the levels of HMGCR, ki67, pro-caspase-3, cleaved-caspase-3, and lactate dehydrogenase A chain (LDHA). The interaction between miR-204-5p and LINC00202 or HMGCR was analyzed by the dual-luciferase reporter assay. Murine xenograft model was established to conduct in vivo experiments. LINC00202 expression was upregulated in RB tumor tissues and LINC00202 knockdown inhibited RB cell proliferation, glycolysis, and stimulated apoptosis in vitro as well as impeded tumor growth in vivo. MiR-204-5p directly bound to LINC00202 and HMGCR in RB cells, and LINC00202 functioned as a competing endogenous RNA in regulating HMGCR through competitively binding to miR-204-5p. More importantly, the regulation of malignant properties and glycolysis of RB cells mediated by LINC00202 could be reversed by abnormal miR-204-5p or HMGCR expression in RB cells. In all, LINC00202 promoted RB cell proliferation, glycolysis, and suppressed apoptosis by regulating the miR-204-5p/HMGCR axis, suggesting a novel therapeutic target for patients with RB.

FASN-Mediated Lipid Metabolism Regulates Goose Granulosa Cells Apoptosis and Steroidogenesis

Lipid metabolism participates in regulating the functions of granulosa cells (GCs), which is important for follicular development. In this experiment, goose GCs from pre-hierarchical follicles and hierarchical follicles were selected to be the model for studying the putative regulatory role of lipid metabolism in apoptosis and steroidogenesis, through overexpression and interference with fatty acid synthase (FASN). When FASN was overexpressed, the lipid accumulation was increased in hierarchical GCs (hGCs) and it was increased in the two categorized GCs when FASN was interfered. In addition, the apoptosis of the two categorized GCs was increased when FASN was overexpressed, and their progesterone production was decreased when FASN was interfered. The results of qRT-PCR showed that, when FASN was overexpressed, the expression level of CYP11A1 was decreased in pre-hierarchical GCs (phGCs), while the expression levels of SCD1, DGAT2, APOB, and StAR were increased in hGCs. When FASN was interfered, the expression levels of CPT-1, DGAT2, and StAR were decreased whereas the expression level of CYP11A1 was increased in phGCs, and the expression levels of CPT-1, SCD1, and StAR were decreased in hGCs. These results not only identify the different effects of manipulated FASN expression on lipid metabolism of goose phGCs and hGCs but also demonstrate that FASN-mediated lipid metabolism plays an important role in regulating apoptosis and steroidogenesis of in vitro cultured goose GCs.

miR-15/107 microRNA Gene Group: Characteristics and Functional Implications in Cancer

The miR-15/107 group of microRNAs (miRNAs) encloses 10 annotated human members and is defined based on the presence of the sequence AGCAGC near the mature miRNAs’ 5′ end. Members of the miR-15/107 group expressed in humans are highly evolutionarily conserved, and seven of these miRNAs are widespread in vertebrate species. Contrary to the majority of miRNAs, which recognize complementary sequences on the 3′UTR region, some members of the miR-15/107 group are peculiarly characterized by the ability to target the coding sequence (CDS) of their target mRNAs, inhibiting translation without strongly affecting their mRNA levels. There is compelling evidence that different members of the miR-15/107 group regulate overlapping lists of mRNA targets but also show target specificity. The ubiquitously expressed miR-15/107 gene group controls several human cellular pathways, such as proliferation, angiogenesis, and lipid metabolism, and might be altered in various diseases, such as neurodegenerative diseases and cancer. Intriguingly, despite sharing the same seed sequence, different members of this family of miRNAs may behave as oncomiRs or as tumor suppressor miRNAs in the context of cancer cells. This review discusses the regulation and functional contribution of the miR-15/107 group to the control of gene expression. Moreover, we particularly focus on the contribution of specific miR-15/107 group members as tumor suppressors in breast cancer, reviewing literature reporting their ability to function as major controllers of a variety of cell pathways and to act as powerful biomarkers in this disease.

MicroRNA-195 inhibits proliferation and metastasis in renal cell carcinoma via regulating HMGA1

Growing evidence indicates that aberrant expression of microRNAs (miRNAs) contributes to tumorigenesis in various human malignancies. In this study we revealed that miR-195 acted as a tumor suppressor in renal cell carcinoma (RCC) through inhibition of HMGA1 expression. qRT-PCR was used to detect the miR-195 expression in RCC tissues and cell lines. RCC cell line Caki-1 and Caki-2 cells were used in this study. The luciferase report assay and rescue assay were performed to identify HMGA1 as the target gene of miR-195. Additionally, Kaplan-Meier method and log-rank test was used to explore the relationship between HMGA1 expression and RCC prognosis. We observed that miR-195 expression was significantly downregulated both in RCC tissues and in RCC cell lines. We observed that miR-195 overexpression inhibits the abilities of RCC cell proliferation, cell cycle progression and metastasis in vitro by targeting HMGA1 via epithelial to mesenchymal transition (EMT) pathway. In clinical specimens, HMGA1 was overexpressed in high-grade RCC when compared with its levels in normal tissues and low-grade RCC cancer, its expression levels were inversely correlated with overall survival. Our findings highlight an important role of miR-195 and HMGA1 in the molecular etiology of RCC, indicating that they can serve as potential biomarkers and therapy targets of RCC.

MiR-195 enhances cardiomyogenic differentiation of the proepicardium/septum transversum by Smurf1 and Foxp1 modulation

Cardiovascular development is a complex developmental process in which multiple cell lineages are involved, namely the deployment of first and second heart fields. Beside the contribution of these cardiogenic fields, extracardiac inputs to the developing heart are provided by the migrating cardiac neural crest cells and the proepicardial derived cells. The proepicardium (PE) is a transitory cauliflower-like structure located between the cardiac and hepatic primordia. The PE is constituted by an internal mesenchymal component surrounded by an external epithelial lining. With development, cells derived from the proepicardium migrate to the neighboring embryonic heart and progressive cover the most external surface, leading to the formation of the embryonic epicardium. Experimental evidence in chicken have nicely demonstrated that epicardial derived cells can distinctly contribute to fibroblasts, endothelial and smooth muscle cells. Surprisingly, isolation of the developing PE anlage and ex vivo culturing spontaneously lead to differentiation into beating cardiomyocytes, a process that is enhanced by Bmp but halted by Fgf administration. In this study we provide a comprehensive characterization of the developmental expression profile of multiple microRNAs during epicardial development in chicken. Subsequently, we identified that miR-125, miR-146, miR-195 and miR-223 selectively enhance cardiomyogenesis both in the PE/ST explants as well as in the embryonic epicardium, a Smurf1- and Foxp1-driven process. In addition we identified three novel long non-coding RNAs with enhanced expression in the PE/ST, that are complementary regulated by Bmp and Fgf administration and well as by microRNAs that selectively promote cardiomyogenesis, supporting a pivotal role of these long non coding RNAs in microRNA-mediated cardiomyogenesis of the PE/ST cells.

MicroRNA-195 reverses the resistance to temozolomide through targeting cyclin E1 in glioma cells

Glioma is the most common malignant tumor of the central nervous system with poor survival. Temozolomide (TMZ) is the first-line chemotherapy drug for initial and recurrent glioma treatment with a relatively good efficacy, which exerts its antitumor effects mainly through cell death induced by DNA double-strand breaks in the G1 and S phases. However, endogenous or acquired resistance to TMZ limits glioma patients’ clinical outcome and is also an important cause of glioma replase. MicroRNA-195 (miR-195) plays an important role in the regulation of G1-phase/S-phase transition, DNA damage repair, and apoptosis of tumor cells. We found that miR-195 expression was significantly decreased in TMZ-resistant glioma cells induced with TMZ and correlated to the resistance index negatively. Also, the exogenous expression of miR-195 reversed TMZ resistance and induced the apoptosis of TMZ-resistant glioblastoma cells. Further bioinformatics analysis showed cyclin E1 (CCNE1) was a potential target gene of miR-195. Knockdown of CCNE1 partially reversed the effect of decreased miR-195 on TMZ resistance. The data from The Cancer Genome Atlas – Cancer Genome further suggested that hsa-miR-195 could negatively regulate the expression of CCNE1 in glioma. In conclusion, miR-195 reverses the resistance to TMZ by targeting CCNE1 in glioma cells and it could act as a potential target for treatment in glioma with TMZ resistance.

TGFβ-induced metabolic reprogramming during epithelial-to-mesenchymal transition in cancer

Metastasis is the most frequent cause of death in cancer patients. Epithelial-to-mesenchymal transition (EMT) is the process in which cells lose epithelial integrity and become motile, a critical step for cancer cell invasion, drug resistance and immune evasion. The transforming growth factor-β (TGFβ) signaling pathway is a major driver of EMT. Increasing evidence demonstrates that metabolic reprogramming is a hallmark of cancer and extensive metabolic changes are observed during EMT. The aim of this review is to summarize and interconnect recent findings that illustrate how changes in glycolysis, mitochondrial, lipid and choline metabolism coincide and functionally contribute to TGFβ-induced EMT. We describe TGFβ signaling is involved in stimulating both glycolysis and mitochondrial respiration. Interestingly, the subsequent metabolic consequences for the redox state and lipid metabolism in cancer cells are found to be in favor of EMT as well. Combined we illustrate that a better understanding of the mechanistic links between TGFβ signaling, cancer metabolism and EMT holds promising strategies for cancer therapy, some of which are already actively being explored in the clinic.

Dissecting miRNA facilitated physiology and function in human breast cancer for therapeutic intervention

MicroRNAs (miRNAs) are key epigenomic regulators of biological processes in animals and plants. These small non coding RNAs form a complex networks that regulate cellular function and development. MiRNAs prevent translation by either inactivation or inducing degradation of mRNA, a major concern in post-transcriptional gene regulation. Aberrant regulation of gene expression by miRNAs is frequently observed in cancer. Overexpression of various 'oncomiRs' and silencing of tumor suppressor miRNAs are associated with various types of human cancers, although overall downregulation of miRNA expression is reported as a hallmark of cancer. Modulations of the total pool of cellular miRNA by alteration in genetic and epigenetic factors associated with the biogenesis of miRNA machinery. It also depends on the availability of cellular miRNAs from its store in the organelles which affect tumor development and cancer progression. Here, we have dissected the roles and pathways of various miRNAs during normal cellular and molecular functions as well as during breast cancer progression. Recent research works and prevailing views implicate that there are two major types of miRNAs; (i) intracellular miRNAs and (ii) extracellular miRNAs. Concept, that the functions of intracellular miRNAs are driven by cellular organelles in mammalian cells. Extracellular miRNAs function in cell-cell communication in extracellular spaces and distance cells through circulation. A detailed understanding of organelle driven miRNA function and the precise role of extracellular miRNAs, pre- and post-therapeutic implications of miRNAs in this scenario would open several avenues for further understanding of miRNA function and can be better exploited for the treatment of breast cancers.

Non-Coding RNAs Operate in the Crosstalk Between Cancer Metabolic Reprogramming and Metastasis

Metastasis, the spread of cancer cells from a primary tumor to a secondary site, represents one of the hallmarks of malignancies and the leading cause of cancer-related death. The process of metastasis is a result of the interaction of genetic heterogeneity, abnormal metabolism, and tumor microenvironments. On the other hand, metabolic reprogramming, another malignancy hallmark, refers to the ability of cancer cells to alter metabolic and nutrient acquisition modes in order to support the energy demands for accomplishing the rapid growth, dissemination, and colonization. Cancer cells remodel metabolic patterns to supplement nutrients for their metastasis and also undergo metabolic adjustments at different stages of metastasis. Genes and signaling pathways involved in tumor metabolic reprogramming crosstalk with those participating in metastasis. Non-coding RNAs are a group of RNA molecules that do not code proteins but have pivotal biological functions. Some of microRNAs and lncRNAs, which are the two most extensively studied non-coding RNAs, have been identified to participate in regulating metabolic remodeling of glucose, lipid, glutamine, oxidative phosphorylation, and mitochondrial respiration, as well as the process of metastasis involving cell motility, transit in the circulation and growth at a new site. This article reviews recent progress on non-coding RNAs operating in the crosstalk between tumor metabolic reprogramming and metastasis, particularly those influencing metastasis through regulating metabolism, and the underlying mechanisms of how they exert their regulatory functions.

microRNAs targeting cellular cholesterol: implications for combating anticancer drug resistance

Over sixty percent of all mammalian protein-coding genes are estimated to be regulated by microRNAs (miRNAs), and unsurprisingly miRNA dysregulation has been linked with cancer. Aberrant miRNA expression in cancer cells has been linked with tumourigenesis and drug resistance. In the past decade, increasing number of studies have demonstrated that cholesterol accumulation fuels tumour growth and contributes to drug resistance, therefore, miRNAs controlling cholesterol metabolism and homeostasis are obvious hypothetical targets for investigating their role in cholesterol-mediated drug resistance in cancer. In this review, we have collated published evidences to consolidate this hypothesis and have scrutinized it by utilizing computational tools to explore the role of miRNAs in cholesterol-mediated drug resistance in breast cancer cells. We found that hsa-miR-128 and hsa-miR-223 regulate genes mediating lipid signalling and cholesterol metabolism, cancer drug resistance and breast cancer genes. The analysis demonstrates that targeting these miRNAs in cancer cells presents an opportunity for developing new strategies to combat anticancer drug resistance.

Crosstalk of MicroRNAs and Oxidative Stress in the Pathogenesis of Cancer

Oxidative stress refers to an imbalance between reactive oxygen species (ROS) generation and body's capability to detoxify the reactive mediators or to fix the relating damage. MicroRNAs are considered to be important mediators that play essential roles in the regulation of diverse aspects of carcinogenesis. Growing studies have demonstrated that the ROS can regulate microRNA biogenesis and expression mainly through modulating biogenesis course, transcription factors, and epigenetic changes. On the other hand, microRNAs may in turn modulate the redox signaling pathways, altering their integrity, stability, and functionality, thus contributing to the pathogenesis of multiple diseases. Both ROS and microRNAs have been identified to be important regulators and potential therapeutic targets in cancers. However, the information about the interplay between oxidative stress and microRNA regulation is still limited. The present review is aimed at summarizing the current understanding of molecular crosstalk between microRNAs and the generation of ROS in the pathogenesis of cancer.

MicroRNA 27a Is a Key Modulator of Cholesterol Biosynthesis

Hypercholesterolemia is a strong predictor of cardiovascular diseases. The 3-hydroxy-3-methylglutaryl coenzyme A reductase gene (Hmgcr) coding for the rate-limiting enzyme in the cholesterol biosynthesis pathway is a crucial regulator of plasma cholesterol levels. However, the posttranscriptional regulation of Hmgcr remains poorly understood. The main objective of this study was to explore the role of microRNAs (miRNAs) in the regulation of Hmgcr expression. Systematic in silico predictions and experimental analyses reveal that miRNA 27a (miR-27a) specifically interacts with the Hmgcr 3' untranslated region in murine and human hepatocytes. Moreover, our data show that Hmgcr expression is inversely correlated with miR-27a levels in various cultured cell lines and in human and rodent tissues. Actinomycin D chase assays and relevant experiments demonstrate that miR-27a regulates Hmgcr by translational attenuation followed by mRNA degradation. Early growth response 1 (Egr1) regulates miR-27a expression under basal and cholesterol-modulated conditions. miR-27a augmentation via tail vein injection of miR-27a mimic in high-cholesterol-diet-fed Apoe ^-/- mice shows downregulation of hepatic Hmgcr and plasma cholesterol levels. Pathway and gene expression analyses show that miR-27a also targets several other genes (apart from Hmgcr) in the cholesterol biosynthesis pathway. Taken together, miR-27a emerges as a key regulator of cholesterol biosynthesis and has therapeutic potential for the clinical management of hypercholesterolemia.

Genomic evidence sheds light on the genetic mechanisms of musk secretion in muskrats

Adult male muskrat (Ondatra zibethicus) has a pair of scent glands which secret musk to attract females during the breeding stage. The goal of the present study was to investigate the genetic mechanisms of musk secretion of muskrats at the whole genome level. Comparative genomics illustrated obvious expansion in 809 gene families, of which nine gene families played pivotal roles in steroid biosynthesis, possibly related to muskrat musk secretion. We identified 1112 positively selected genes (PSGs) in the muskrat, including estrogen receptor 1 (ER1), an important influencing factor to the weight and size of the scented glands of muskrats. HSD17B3, HSD17B4, CYP7B1 and CYP17B1, crucial to steroid hormone biosynthesis, were under strong positive selection in the muskrat, and phylogenetic analysis of HSD and CYP450 classes revealed high gene diversity. Functional enrichment revealed many pathways associated with musk secretion and/or growth and degeneration of scented gland significantly, such as peroxisome, PI3K-Akt signaling pathway, apoptosis, and prostate cancer. Two muskrat-specific missense mutations (Pro237Thr and Ser297Ile) were detected in LIPC, which were reported to be involved cholesterol metabolic process. More importantly, the missense mutations discovered in LIPC were classified as deleterious by PolyPhen-2, possibly affecting the musk secretion of muskrats.

Cell-free miRNAs as non-invasive biomarkers in breast cancer: Significance in early diagnosis and metastasis prediction

Breast cancer is one of the genetic diseases causing a high mortality among women around the world. Despite the availability of advanced diagnostic tools and treatment strategies, the incidence of breast cancer is increasing every year. This is due to the lack of accurate and reliable biomarkers whose deficiency creates difficulty in early breast cancer recognition, subtypes determination, and metastasis prophecy. Although biomarkers such as ER, PR, Her2, Ki-67, and other genetic platforms e.g. MammaPrint®, Oncotype DX®, Prosigna® or EndoPredict® are available for determination of breast cancer diagnosis and prognosis. However, pertaining to heterogeneous nature, lack of sensitivity, and specificity of these markers, it is still incessant to overcome breast cancer burden. Therefore, a novel biomarker is urgently needed for therapeutic diagnosis and improving prognosis. Lately, it has become more evident that cell-free miRNAs might be useful as good non-invasive biomarkers that are associated with different events in carcinogenesis. For example, some known biomarkers such as miR-21, miR-23a, miR-34a are associated with molecular subtyping and different biomolecular aspects i.e. apoptosis, angiogenesis, metastasis, and miR-1, miR-10b, miR-16 are associated with drug response. Cell-free miRNAs present in human body fluids have proven to be potential biomarkers with significant prognostic and predictive values. Numerous studies have found a distinct expression profile of circulating miRNAs in breast tumour versus non-tumour and in early and advanced-stage, thus implicating its clinical relevance. This review article will highlight the importance of different cell-free miRNAs as a biomarker for early breast cancer detection, subtype classification, and metastasis forecast.

MicroRNA Tough Decoy Knockdowns miR-195 and Represses Hypertrophy in Chondrocytes

Cartilage hypertrophy is a condition in which the cells are completely differentiated, and new morphological changes and mineralization prevent proper cellular functions. The occurrence of hypertrophy during differentiation fails current regenerative strategies for treatment. Strategies to minimize hypertrophy in chondrocytes are categorized into two levels of protein and gene. Among these strategies, one way to affect multiple pathways involved in the development of hypertrophy is to manage microRNA activity in cells. Recent miRNA profiling studies have shown that miR-195-5p upregulates through the transition from chondrogenic to hypertrophic state. Bioinformatics assessment of microRNA targets also indicates that several genes repressed by miR-195-5p play important roles in processes related to hypertrophy. The aim of this study was to develop a microRNA Tough Decoy to suppress miR-195-5p and investigate whether it can prevent a hypertrophic state in chondrocytes. The Tough Decoy (TUD) was designed and evaluated bioinformatically and then cloned into the pLVX-Puro plasmid. The TUD function was validated by Dual-Luciferase assay and qRT-PCR. After delivering TUD to C28/I2 chondrocytes cultured in a hypertrophic medium, hypertrophic differentiation was assessed by histochemical staining, quantitative RT-PCR of hypertrophy marker genes, and alkaline phosphatase activity. Results showed that the TUD could inhibit miRNA efficiently and downregulate hypertrophic markers such as RUNX2, alkaline phosphatase, and collagen 10 significantly compared with the control group. Alcian blue and alizarin red staining also demonstrated the optimal effect of gene constructs on tissue properties and mineralization of the TUD group. Delivering the miR-195-5p Tough Decoy to the cartilage cells can prevent the occurrence of hypertrophy in chondrocytes and could be considered as a candidate for the treatment of other diseases such as osteoarthritis.

Role of de novo cholesterol synthesis enzymes in cancer

Despite extensive research in the cancer field, cancer remains one of the most prevalent diseases. There is an urgent need to identify specific targets that are safe and effective for the treatment of cancer. In recent years, cancer metabolism has come into the spotlight in cancer research. Lipid metabolism, especially cholesterol metabolism, plays a critical role in membrane synthesis as well as lipid signaling in cancer. This review focuses on the contribution of the de novo cholesterol synthesis pathway to tumorigenesis, cancer progression and metastasis. In conclusion, cholesterol metabolism could be an effective target for novel anticancer treatment.

Dysregulated lncRNA-miRNA-mRNA Network Reveals Patient Survival-Associated Modules and RNA Binding Proteins in Invasive Breast Carcinoma

Breast cancer is the most common cancer in women, but few biomarkers are effective in clinic. Previous studies have shown the important roles of non-coding RNAs in diagnosis, prognosis, and therapy selection for breast cancer and have suggested the significance of integrating molecules at different levels to interpret the mechanism of breast cancer. Here, we collected transcriptome data including long non-coding RNA (lncRNA), microRNA (miRNA), and mRNA for ~1,200 samples, including 1079 invasive breast carcinoma samples and 104 normal samples, from The Cancer Genome Atlas (TCGA) project. We identified differentially expressed lncRNAs, miRNAs, and mRNAs that distinguished invasive carcinoma samples from normal samples. We further constructed an integrated dysregulated network consisting of differentially expressed lncRNAs, miRNAs, and mRNAs and found housekeeping and cancer-related functions. Moreover, 58 RNA binding proteins (RBPs) involved in biological processes that are essential to maintain cell survival were found in the dysregulated network, and 10 were correlated with overall survival. In addition, we identified two modules that stratify patients into high- and low-risk subgroups. The expression patterns of these two modules were significantly different in invasive carcinoma versus normal samples, and some molecules were high-confidence biomarkers of breast cancer. Together, these data demonstrated an important clinical application for improving outcome prediction for invasive breast cancers.

MicroRNA-195 Functions as a Tumor Suppressor by Directly Targeting Fatty Acid Synthase in Malignant Meningioma

OBJECTIVE

Meningiomas are among the most common primary intracranial tumors. Up to 20% of cases will show increased malignancy at histological examination (World Health Organization grade II or III). Effective pharmacotherapy, except for radiotherapy, is lacking. Therefore, it is necessary to study the pathogenesis of malignant meningioma to provide more treatment strategies.

METHODS

RNA sequencing and micro-RNA (miRNA) microarray detection were applied to identify differentially expressed messenger RNAs (mRNAs) and miRNAs in benign and malignant meningioma. The miRDB and TargetScan databases were used to predict the potential interaction between miRNAs and mRNAs. A proliferation assay was used to evaluate the cell growth. A wound healing assay and Transwell assay were performed to assess the cell migration and invasion abilities, respectively. The interaction between miRNA and mRNA was identified using a luciferase reporter assay.

RESULTS

We found fatty acid synthase (FASN) was significantly upregulated in malignant meningioma compared with benign meningioma. Knockdown of FASN significantly inhibited proliferation, migration, and invasion of IOMM-Lee cells. Moreover, miR-195 was verified to directly target FASN using a luciferase reporter assay. Upregulation of miR-195 also significantly inhibited proliferation, migration, and invasion of IOMM-Lee cells. Furthermore, we performed bioinformatics analysis to predict the competing endogenous RNAs (ceRNAs) and found that NUP210, SPIRE2, SLC7A1, and DMTN might function as ceRNAs of FASN by sponging miR-195 in meningioma.

CONCLUSIONS

Our results have suggested a tumor suppressive role for miR-195 in the tumorigenesis and progression of malignant meningioma by targeting FASN. In addition, NUP210, SPIRE2, SLC7A1, and DMTN might act as ceRNAs to regulate FASN expression by sponging miR-195.

Crocetin and crocin decreased cholesterol and triglyceride content of both breast cancer tumors and cell lines

OBJECTIVE

Inhibition of lipid metabolism in breast cancer has been suggested as an effective approach for cancer therapy. Saffron-derived crocetin (Crt) and crocin (Cro) with the known anticancer activity, have shown hypolipidemic effect in diabetes and atherosclerosis. Here, we investigated the effect of Crt/Cro on lipid content in breast cancer.

MATERIALS AND METHODS

A multi-model approach involving in vivo, in vitro and in silico studies was applied. The 4T1-induced breast cancer in mice was used to investigate the effect of Crt/Cro on cholesterol (Chl) and triglyceride (TG) levels in serum and tumor tissues. The Chl/TG levels were also assessed in the cytosol of MDA-MB-231 and MCF-7 breast cancer cell lines 6, 12 and 24 hr after Crt/Cro treatment. The interaction between Crt/Cro and hydroxymethylglutaryl coenzyme A reductase (HMGCR) was also computed by docking analysis.

RESULTS

Crt reduced both serum (p=0.003) and tumor (p=0.011) Chl and TG (p=0.001) levels in mice. Cro reduced TG levels in tumor (p=0.014) and serum (p=0.002) and Chl level in tumor (p=0.013) tissues. Crt reduced both Chl and TG in MDA-MB-231 (p=0.014 and p=0.002, respectively) and MCF-7 (p=0.014 and p=0.002, respectively), after 24 h. Cro reduced both Chl and TG in MDA-MB-231 (p=0.014 and p=0.002, respectively) and MCF-7 (p=0.014 and p=0.002, respectively), after 24 h. Crt binds to the active site of HMGCR with higher affinity (ΔG⁰=-6.6 kcal/mol) than simvastatin (ΔG⁰ =-6.0 kcal/mol).

CONCLUSION

Crt and Cro effectively decreased Chl/TG content in the sera of tumor bearing mice, in breast tumors and breast cancer cell lines. Crt showed a higher hypolipidemic potential than Cro. In silico analysis indicated Crt binding in the HMGCR active site.

Association between different levels of lipid metabolism‑related enzymes and fatty acid synthase in Wilms' tumor

Wilms’ tumor is one of the most common malignant tumors of the abdomen in children. However, there is currently no recognized specific biomarker for the clinical diagnosis and prognosis of this tumor. Lipid metabolism is involved in membrane synthesis and oxidation in tumor cells. This process plays an important role in the development of tumors, but it has not yet been investigated in Wilms’ tumor. The aim of the present study was to characterize the changes in lipid metabolism and to contribute to the diagnosis and prognosis of Wilms’ tumor. Proteomics analysis was performed to detect lipid-metabolizing enzymes in 9 tissue samples from Wilms’ tumors and adjacent tissues, and proteomics revealed the presence of 19 differentially expressed lipid-metabolizing enzymes. Protein interaction analysis with the Search Tool for the Retrieval of Interacting Genes/Proteins was used to identify the interacting proteins. Immunohistochemistry (IHC), immunofluorescence and western blotting were used to further confirm whether the expression of fatty acid synthase (FASN) was significantly increased in the tumor tissues. Oncomine database and reverse transcription-PCR analyses further confirmed that the expression of FASN at the gene level was significantly increased in the tumors. Following collection of 65 pediatric cases of Wilms’ tumor at the Shandong Provincial Hospital between 2007 and 2012, the association between the expression of FASN and the clinical characteristics was analyzed, and IHC analysis further demonstrated that FASN expression was significantly associated with tumor stage and size. The association between FASN and the prognosis of children with Wilms’ tumor was analyzed using Kaplan-Meier survival curves. In addition, univariate survival analysis revealed that higher expression of FASN in Wilms’ tumors was associated with poorer prognosis. Our findings revealed that FASN may be used as a prognostic biomarker in patients with Wilms’ tumor. Furthermore, lipid metabolism may play an important role in the occurrence and development of Wilms’ tumor.

VGLL4 interacts with STAT3 to function as a tumor suppressor in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive malignancy with a poor prognosis, and there are no effective molecular-targeted drugs for TNBC patients in clinical practice. The JAK-STAT pathway is implicated in tumorigenesis and the progression of various cancers. In this study, the results demonstrated that VGLL4 is expressed at low levels in both TNBC specimens and cell lines and that VGLL4 expression is negatively correlated with Ki67 expression and tumor size in TNBC patients. VGLL4 knockdown can promote the growth of TNBC cells, while VGLL4 overexpression significantly suppresses the growth of TNBC cells in vitro. More importantly, VGLL4 significantly inhibits tumor progression in a nude mouse model. In addition, VGLL4 is a direct target of miR-454, and the upregulation of miR-454 decreases VGLL4 expression and promotes the cell growth of TNBC cells. Furthermore, we also demonstrated that VGLL4 interacts with STAT3, the core component of the JAK-STAT pathway, leading to the inactivation of STAT3 and the inhibition of STAT3 downstream transcription. Collectively, these findings indicate that VGLL4 expression is negatively associated with poor prognosis in TNBC patients. High expression of miR-454 may be one of the causes of the downregulation of VGLL4 in TNBC, and VGLL4 acts as a tumor suppressor in TNBC by interacting with STAT3 and subsequently suppresses the STAT3 signaling axis, providing potential biomarkers and therapeutic approaches for this fatal disease.

Targeting the regulation or activity of a tumor suppressor protein that is deactivated in triple-negative breast cancer (TNBC) holds promise for the treatment of this highly aggressive form of cancer. Lin Fang and colleagues at Tongji University in Shanghai, China, showed that low levels of the protein vestigial-like family member 4 (VGLL4) promoted TNBC cell proliferation and migration, whereas overexpression of VGLL4 prevented the growth of these cells in mice. VGLL4 acts as a tumor suppressor by interfering with a signaling pathway that drives tumor growth. Furthermore, they found that VGLL4 expression is regulated by a small RNA molecule that is highly expressed in TNBC patients with poor prospects of survival. These findings provide new insights into the mechanisms underlying TNBC and highlight potential strategies for the development of targeted therapies.

LncRNA SNHG16 induces the SREBP2 to promote lipogenesis and enhance the progression of pancreatic cancer

Aim: Blocking lipogenesis could significantly inhibit the progression of pancreatic cancer. Exploring the regulatory mechanisms of lipogenesis by lncRNA SNHG16 might be of great significance to control the development of pancreatic cancer. Methods: The proliferation, migration, invasion and lipogenesis were determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, transwell and Oil Red O staining assays, respectively. The interactions among lncRNA SNHG16, miR-195 and SREBP2 were analyzed by dual luciferase reporter assays. Results: Both the knock down of lncRNA SNHG16 and SREBP2 and overexpression of miR-195 suppressed the proliferation, migration, invasion and lipogenesis in pancreatic cancer cells. LncRNA SNHG16 directly sponged miR-195 to modulate the lipogenesis via regulating the expression of SREBP2. Conclusion: LncRNA SNHG16 accelerated the development of pancreatic cancer and promoted lipogenesis via directly regulating miR-195/SREBP2 axis.

Vitamin D Receptor Gene Expression in Adipose Tissue of Obese Individuals is Regulated by miRNA and Correlates with the Pro-Inflammatory Cytokine Level

Background: Given the role that vitamin D (VD) plays in the regulation of the inflammatory activity of adipocytes, we aimed to assess whether obesity changes the expression of VD-related genes in adipose tissue and, if so, to investigate whether this phenomenon depends on microRNA interference and how it may influence the local inflammatory milieu. Methods: The expression of genes encoding VD 1α-hydroxylase (CYP27B1), 24-hydroxylase (CYP24A1) and receptor (VDR), selected interleukins and microRNAs was evaluated by real-time PCR in visceral (VAT) and in subcutaneous (SAT) adipose tissues of 55 obese (BMI > 40 kg/m²) and 31 normal-weight (BMI 20–24.9 kg/m²) individuals. Results: VDR mRNA levels were higher, while CYP27B1 levels were lower in adipose tissues of obese patients than in those of normal-weight controls (VAT: P = 0.04, SAT: P < 0.0001 and VAT: P = 0.004, SAT: P = 0.016, respectively). The expression of VDR in VAT of obese subjects correlated negatively with levels of miR-125a-5p (P = 0.0006, r_s = −0.525), miR-125b-5p (P = 0.001, r_s = −0.495), and miR-214-3p (P = 0.009, r_s = −0.379). Additionally, VDR mRNA concentrations in visceral adipose tissues of obese subjects correlated positively with mRNA levels of interleukins: 1β, 6 and 8. Conclusions: We observed obesity-associated up-regulation of VDR and down-regulation of CYP27B mRNA levels in adipose tissue. VDR expression correlates with the expression of pro-inflammatory cytokines and may be regulated by miRNAs.

miRNA expression changes during the course of neoadjuvant bevacizumab and chemotherapy treatment in breast cancer

One of the hallmarks of cancer is sustained angiogenesis. Favorable results have been reported in some breast cancer (BC) patients receiving antiangiogenic therapy with bevacizumab (Bev) in combination with chemotherapy, and further knowledge on how Bev can be optimally combined with conventional treatment to increase efficacy is strongly needed. In this randomized, neoadjuvant phase II clinical trial, 132 patients with HER2-negative, nonmetastatic BC were treated with Bev in combination with sequential chemotherapy. Biopsies were sampled before treatment, after 12 weeks with anthracycline and after taxane therapy at week 25. MicroRNA (miRNA) expression profiling was performed on biopsies from each time point. Altogether, 241 biopsies were analyzed with the aim of identifying miRNA-based biomarkers of response to therapy. Results from the miRNA analyses were reported for the ER-positive cohort, which were previously demonstrated to benefit from antiangiogenic therapy in this study. For both treatment arms of this cohort, significantly different expression was observed for 217 miRNAs between objective responding and nonresponding patients before treatment initiation. These miRNAs have been linked to regulation of epithelial-mesenchymal transition, metastasis, and tumor growth, among other processes. Bev in combination with chemotherapy resulted in similar miRNA changes to chemotherapy alone. However, the deregulation of miRNA expression occurred earlier in the Bev arm. In both arms, tumor suppressor miRNAs were found upregulated after treatment, while oncogenic miRNAs were downregulated in the Bev arm. Patients responding to Bev showed a strong correlation between deregulated miRNAs and decreased proliferation score during the course of treatment, with downregulation of miR-4465 as the strongest indicator of reduced proliferation. Integrative analyses at miRNA-, gene-, and protein expression further indicated a longitudinal decrease in proliferation. Altogether, the results indicate that proliferation might represent a predictive factor for increased Bev sensitivity, which may aid in the identification of patients who could potentially benefit from Bev.

An Inhibitor of Fatty Acid Synthase Thioesterase Domain with Improved Cytotoxicity against Breast Cancer Cells and Stability in Plasma

It is well recognized that many cancers are addicted to a constant supply of fatty acids (FAs) and exhibit brisk de novo FA synthesis. Upregulation of a key lipogenic enzyme, fatty acid synthase (FASN), is a near-universal feature of human cancers and their precursor lesions, and has been associated with chemoresistance, tumor metastasis, and diminished patient survival. FASN inhibition has been shown to be effective in killing cancer cells, but progress in the field has been hindered by off-target effects and poor pharmaceutical properties of candidate compounds. Our initial hit (compound 1) was identified from a high-throughput screening effort by the Sanford-Burnham Center for Chemical Genomics using purified FASN thioesterase (FASN-TE) domain. Despite being a potent inhibitor of purified FASN-TE, compound 1 proved highly unstable in mouse plasma and only weakly cytotoxic to breast cancer (BC) cells in vitro. An iterative process of synthesis, cytotoxicity testing, and plasma stability assessment was used to identify a new lead (compound 41). This lead is more cytotoxic against multiple BC cell lines than tetrahydro-4-methylene-2S-octyl-5-oxo-3R-furancarboxylic acid (the literature standard for inhibiting FASN), is stable in mouse plasma, and shows negligible cytotoxic effects against nontumorigenic mammary epithelial cells. Compound 41 also has drug-like physical properties based on Lipinski's rules and is, therefore, a valuable new lead for targeting fatty acid synthesis to exploit the requirement of tumor cells for fatty acids. SIGNIFICANCE STATEMENT: An iterative process of synthesis and biological testing was used to identify a novel thioesterase domain FASN inhibitor that has drug-like properties, is more cytotoxic to breast cancer cells than the widely used tetrahydro-4-methylene-2S-octyl-5-oxo-3R-furancarboxylic acid, and has negligible effects on the growth and proliferation of noncancerous mammary epithelial cells. Our studies have confirmed the value of using potent and selective FASN inhibitors in the treatment of BC cells and have shown that the availability of exogenous lipoproteins may impact both cancer cell FA metabolism and survival.

Fluvastatin Inhibits HMG-CoA Reductase and Prevents Non-Small Cell Lung Carcinogenesis

Lung cancer is the leading cause of cancer-related death worldwide. However, promising agents for lung cancer prevention are still very limited. Identification of preventive targets and novel effective preventive agents is urgently needed for clinical applications. In this study, we found that fluvastatin targeted 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR), which a rate-limiting enzyme in the mevalonate pathway, and inhibited non-small cell lung cancer (NSCLC) tumorigenesis. Initially, we demonstrated that HMGCR is overexpressed in human lung adenocarcinoma tissues compared with normal tissues. Knockdown of HMGCR in NSCLC cells attenuated growth and induced apoptosis in vitro and in vivo Furthermore, we found that fluvastatin, an inhibitor of HMGCR, suppressed NSCLC cell growth and induced apoptosis. Intriguingly, fluvastastin functions by inhibiting the HMGCR-driven Braf/MEK/ERK1/2 and Akt signaling pathways. Notably, fluvastatin attenuated tumor growth in 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis and in a patient-derived xenograft lung tumor model. Overall, our findings suggest that fluvastatin might be promising chemopreventive or potential therapeutic drug against NSCLC tumorigenesis, providing hope for rapid clinical translation.

Long intergenic noncoding RNA SNHG16 interacts with miR-195 to promote proliferation, invasion and tumorigenesis in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been confirmed crucial regulators in tumorgenesis. Small nucleolar RNA host gene 16 (SNHG16) has been recently shown to be dysregulated, which uncovered to be a potential oncogene in some cancers. However, the biological function and potential mechanism of SNHG16 in hepatocellular carcinoma (HCC) remain unclear. In our study, our observations showed that the expression level of SNHG16 in HCC tissues and cell lines was upregulated compared with adjacent noncancerous tissues and normal cells. In vitro, loss-of-function experiments revealed that SNHG16 knockdown suppressed the proliferation and weakened invasion of SMMC7721 and HepG2 cells. miR-195 expression was significantly decreased in HCC tissues and negatively correlated with SNHG16 expression. Furthermore, RIP and dual luciferase reporter assays showed that SNHG16 acted as an endogenous sponge by directly binding to miR-195 and downregulated its expression. SNHG16 overexpression inverted the inhibitory effect of miR-195 on proliferation and invasion of SMMC7721 and HepG2 cells. Additionally, SNHG16 depletion resulted in lower tumor growth and weight loss, in vivo. In conclusion, our findings reported that the oncogenic role of SNHG16 in HCC tumorigenesis through a novel SNHG16-miR-195 axis, which provided a novel insight for HCC and helped to probe a potential therapeutic target for the deadly disease.

Integrated bioinformatics analysis reveals novel hub genes closely associated with pathological mechanisms of immunoglobulin A nephropathy

Immunoglobulin A (IgA) nephropathy (IgAN) is the most common glomerular disease. The major pathological changes associated with it affect cell proliferation, fibrosis, apoptosis, inflammation and extracellular matrix (ECM) organization. However, the molecular events underlying IgAN remain to be fully elucidated. In the present study, an integrated bioinformatics analysis was applied to further explore novel potential gene targets for IgAN. The mRNA expression profile datasets GSE93798 and GSE37460 were downloaded from the Gene Expression Omnibus database. After data preprocessing, differentially expressed genes (DEGs) were identified. Gene Ontology (GO) enrichment analysis of DEGs was performed. Protein-protein interaction (PPI) networks of the DEGs were built with the STRING online search tool and visualized by using Cytoscape, and hub genes were identified through the degree of connectivity in the PPI. The hub genes were subjected to Kyoto Encyclopedia of Genes and Genomes pathway analysis, and co-expression analysis was performed. A total of 298 DEGs between IgAN and control groups were identified, and 148 and 150 of these DEGs were upregulated and downregulated, respectively. The DEGs were enriched in distinct GO terms for Biological Process, including cell growth, epithelial cell proliferation, ERK1 and ERK2 cascades, regulation of apoptotic signaling pathway and ECM organization. The top 10 hub genes were then screened from the PPI network by Cytoscape. As novel hub genes, Fos proto-oncogene, AP-1 transcription factor subunit and early growth response 1 were determined to be closely associated with apoptosis and cell proliferation in IgAN. Tumor protein 53, integrin subunit β2 and fibronectin 1 may also be involved in the occurrence and development of IgAN. Co-expression analysis suggested that these hub genes were closely linked with each other. In conclusion, the present integrated bioinformatics analysis provided novel insight into the molecular events and novel candidate gene targets of IgAN.

Non-coding RNAs derailed: The many influences on the fatty acid reprogramming of cancer

Non-coding RNAs (NcRNAs), a family of functional RNA molecules that cannot translate into proteins but control specific gene expression programs, have been shown to be implicated in various biological processes, including fatty acid metabolism. Fast-growing tumor cells rewire their fatty acid metabolic circuitry in order to meet the needs of energy storage, membrane proliferation, and the generation of signaling molecules, which is achieved by regulating a variety of key enzymes along with related signaling pathways in fatty acid metabolism. This review presents an update of our knowledge about the regulatory network of ncRNAs-specifically, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs)-in this metabolic shift and discusses the possibility of ncRNA-based therapeutics being applied to the restoration of cancer-related fatty acid metabolism.

Circulating microRNAs miR-331 and miR-195 differentiate local luminal a from metastatic breast cancer

BACKGROUND

Breast cancer is the leading cause of cancer related death in women, with metastasis the principle cause of mortality. New non-invasive prognostic markers are needed for the early detection of metastasis, facilitating treatment decision optimisation. MicroRNA (miRNA) are small, non-coding RNAs regulating gene expression and involved in many cellular processes, including metastasis. As biomarkers, circulating miRNAs (in blood) hold great promise for informing diagnosis or monitoring treatment responses.

METHODS

Plasma extracted RNA from age matched local Luminal A (n = 4) or metastatic disease (n = 4) were profiled using Next Generation Sequencing. Selected differentially expressed miRNA were validated on a whole blood extracted miRNA cohort [distant metastatic disease (n = 22), local disease (n = 31), healthy controls (n = 21)]. Area Under the Curve (AUC) in Receiver Operating Characteristic (ROC) analyses was performed.

RESULTS

Of 4 miRNA targets tested (miR-181a, miR-329, miR-331, miR-195), mir-331 was significantly over-expressed in patients with metastatic disease, compared to patients with local disease (p < 0.001) or healthy controls (p < 0.001). miR-195 was significantly under-expressed in patients with metastatic disease, compared to patients with local disease (p < 0.001) or healthy controls (p = 0.043). In combination, miR-331 and miR-195 produced an AUC of 0.902, distinguishing metastatic from local breast cancer.

CONCLUSIONS

We identified and validated two circulating miRNAs differentiating local Luminal A breast cancers from metastatic breast cancers. Further investigation will reveal the molecular role of these miRNAs in metastasis, and determine if they are subtype specific. This work demonstrates the ability of circulating miRNA to identify metastatic disease, and potentially inform diagnosis or treatment effectiveness.

MiR-195 regulates mitochondrial function by targeting mitofusin-2 in breast cancer cells

Mitochondrial dynamics is a highly dysregulated process in cancer. Apoptosis and mitochondrial fission are two concurrent events wherein increased mitochondrial fragmentation serves as a hallmark of apoptosis. We have shown earlier that miR-195 exerts pro-apoptotic effects in breast cancer cells. Herein, we have demonstrated miR-195 as a modulator of mitochondrial dynamics and function. Imaging experiments upon miR-195 treatment have shown that mitochondria undergo extensive fission. We validated mitofusin2 as a potential target of miR-195. This may provide a molecular explanation for the respiratory defects induced by miR-195 over-expression in breast cancer cells. Active, but not total, mitochondrial mass, was reduced with increasing levels of miR-195. We have further shown that miR-195 enhances mitochondrial SOD-2 expression but does not affect PINK1 levels in breast cancer cells. Collectively, we have revealed that miR-195 is a modulator of mitochondrial dynamics by targeting MFN2 thereby impairing mitochondrial function. Concomitantly, it enhances the scavenger of reactive oxygen species (SOD-2) to maintain moderate levels of oxidative stress. Our findings suggest a therapeutic potential of miR-195 in both ER-positive as well as ER-negative breast cancer cells.

Role of Metabolic Reprogramming in Epithelial⁻Mesenchymal Transition (EMT)

Activation of epithelial–mesenchymal transition (EMT) is thought to be an essential step for cancer metastasis. Tumor cells undergo EMT in response to a diverse range of extra- and intracellular stimulants. Recently, it was reported that metabolic shifts control EMT progression and induce tumor aggressiveness. In this review, we summarize the involvement of altered glucose, lipid, and amino acid metabolic enzyme expression and the underlying molecular mechanisms in EMT induction in tumor cells. Moreover, we propose that metabolic regulation through gene-specific or pharmacological inhibition may suppress EMT and this treatment strategy may be applied to prevent tumor progression and improve anti-tumor therapeutic efficacy. This review presents evidence for the importance of metabolic changes in tumor progression and emphasizes the need for further studies to better understand tumor metabolism.

Exome sequencing in 51 early onset non-familial CRC cases

Background

Colorectal cancer (CRC) cases with an age of onset <40 years suggests a germline genetic cause. In total, 51 simplex cases were included to test the hypothesis of CRC as a mendelian trait caused by either heterozygous autosomal dominant or bi‐allelic autosomal recessive pathogenic variants.

Methods

The cohort was whole exome sequenced (WES) at 100× coverage. Both a dominant‐ and recessive model were used for searching predisposing genetic factors. In addition, we assayed recessive variants of potential moderate risk that were enriched in our young‐onset CRC cohort. Variants were filtered using a candidate cancer gene list or by selecting variants more likely to be pathogenic based on variant type (e.g., loss‐of‐function) or allele frequency.

Results

We identified one pathogenic variant in PTEN in a patient subsequently confirmed to have a hereditary hamartoma tumor syndrome (Cowden syndrome) and one patient with a pathogenic heterozygous variant in PMS2 that was originally not identified by WES due to low quality reads resulting from pseudogenes. In addition, we identified three heterozygous candidate missense variants in known cancer susceptibility genes (BMPR1A,BRIP1, and SRC), three truncating variants in possibly novel cancer genes (CLSPN,SEC24B, SSH2) and four candidate missense variants in ACACA, NR2C2, INPP4A, and DIDO1. We also identify five possible autosomal recessive candidate genes: ATP10B,PKHD1,UGGT2,MYH13,TFF3.

Conclusion

Two clear pathogenic variants were identified in patients that had not been identified clinically. Thus, the chance of detecting a hereditary cancer syndrome in patients with CRC at young age but without family history is 2/51 (4%) and therefore the clinical benefit of genetic testing in this patient group is low. Of note, using stringent filtering, we have identified a total of ten candidate heterozygous variants and five possibly biallelic autosomal recessive candidate genes that warrant further study.

microRNA-Mediated Tumor-Microbiota Metabolic Interactions in Colorectal Cancer

Worldwide, colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Recent advances in high-throughput technologies have shown that the gut microbiota may have a major influence on human health, including CRC. Nonetheless, how the gut microbiota interacts with tumor cells in CRC patients is largely unknown. Studies have shown that the microbiota fills in a variety of niche metabolic pathways that the host does not possess. For example, the microbiota produces butyrate, which provides the colon's epithelial cells with about 70% of their energy needs. The typically fast proliferation of tumor cells in CRC patients drastically alters the tumor's nutrient microenvironment. Those alterations correspond to the microbiota composition and functional changes. In tumor cells, a central mediator of metabolic changes is the aberrant expression of microRNAs (miRNAs). In this study, we explored recent insights into metabolic interactions between the microbiota and tumor cells in CRC pathobiology, focusing on the role of miRNAs. These observations support our view that miRNAs may also serve as mediators of the metabolites' effects.

The circRNA circAGFG1 acts as a sponge of miR-195-5p to promote triple-negative breast cancer progression through regulating CCNE1 expression

Background

In recent years, circular RNAs (circRNAs), a new star of non-coding RNA, have been emerged as vital regulators and gained much attention for involvement of initiation and progression of diverse kinds of human diseases, especially cancer. However, regulatory role, clinical significance and underlying mechanisms of circRNAs in triple-negative breast cancer (TNBC) still remain largely unknown.

Methods

Here, the expression profile of circRNAs in 4 pairs of TNBC tissues and adjacent non-tumor tissues was analyzed by RNA-sequencing. Quantitative real-time PCR and in situ hybridization were used to determine the level and prognostic values of circAGFG1 in two TNBC cohorts. Then, functional experiments in vitro and in vivo were performed to investigate the effects of circAGFG1 on tumor growth and metastasis in TNBC. Mechanistically, fluorescent in situ hybridization, dual luciferase reporter assay, RNA pull-down and RNA immunoprecipitation experiments were performed to confirm the interaction between circAGFG1 and miR-195-5p in TNBC.

Results

We found that circAGFG1 was evidently up-regulated in TNBC, and its level was correlated with clinical stage, pathological grade and poor prognosis of patients with TNBC. The results indicated that circAGFG1 could promote TNBC cell proliferation, mobility and invasion as well as tumorigenesis and metastasis in vivo. Mechanistic analysis showed that circAGFG1 may act as a ceRNA (competing endogenous RNA) of miR-195-5p to relieve the repressive effect of miR-195-5p on its target cyclin E1 (CCNE1).

Conclusions

Our findings suggest that circAGFG1 promotes TNBC progression through circAGFG1/miR-195-5p/CCNE1 axis and it may serve as a new diagnostic marker or target for treatment of TNBC patients.

Electronic supplementary material

The online version of this article (10.1186/s12943-018-0933-7) contains supplementary material, which is available to authorized users.

Regulation of cytochrome P450 expression by microRNAs and long noncoding RNAs: Epigenetic mechanisms in environmental toxicology and carcinogenesis

Environmental exposures to hazardous chemicals are associated with a variety of human diseases and disorders, including cancers. Phase I metabolic activation and detoxification reactions catalyzed by cytochrome P450 enzymes (CYPs) affect the toxicities of many xenobiotic compounds. Proper regulation of CYP expression influences their biological effects. Noncoding RNAs (ncRNAs) are involved in regulating CYP expression, and ncRNA expression is regulated in response to environmental chemicals. The mechanistic interactions between ncRNAs and CYPs associated with the toxicity and carcinogenicity of environmental chemicals are described in this review, focusing on microRNA-dependent CYP regulation. The role of long noncoding RNAs in regulating CYP expression is also presented and new avenues of research concerning this regulatory mechanism are described.

HSP90 interacts with HMGCR and promotes the progression of hepatocellular carcinoma

Heat shock protein 90 (HSP90) has been reported to promote the growth and inhibit apoptosis of hepatocellular carcinoma (HCC) cells. However, the underlying mechanisms are not fully understood. Immunostaining of the tissue array demonstrated that HSP90 was upregulated in HCC clinical samples and was associated with clinical features. HSP90 interacted with 3‑hydroxy‑3‑methylglutaryl‑CoA reductase (HMGCR), the rate‑limiting enzyme of mevalonate pathway, in the immunoprecipitation assay and regulated its protein expression level by inhibiting protein degradation. In addition, lovastatin, an inhibitor of HMGCR, impaired the oncogenic functions of HSP90 in the cell growth, migration and colony formation assays. Taken together, this study demonstrated that HSP90 promoted the progression of HCC by positively regulating the mevalonate pathway and indicated that HSP90 may be a promising therapeutic target.