SIRT6 promotes metastasis and relapse in HER2-positive breast cancer.

The histone deacetylase sirtuin 6 (SIRT6) has been endowed with anti-cancer capabilities in many tumor types. Here, we investigate the impact of SIRT6-overexpression (SIRT6-OE) in Delta16HER2 mice, which are a bona fide model of HER2-positive breast cancer. After an initial delay in the tumor onset, SIRT6-OE induces a more aggressive phenotype of Delta16HER2 tumors promoting the formation of higher number of tumor foci and metastases than controls. This phenotype of SIRT6-OE tumors is associated with cancer stem cell (CSC)-like features and tumor dormancy, and low senescence and oxidative DNA damage. Accordingly, a sub-set of HER2-positive breast cancer patients with concurrent SIRT6-OE has a significant poorer relapse-free survival (RFS) probability than patients with low expression of SIRT6. ChIP-seq, RNA-seq and RT-PCR experiments indicate that SIRT6-OE represses the expression of the T-box transcription factor 3 (Tbx3) by deacetylation of H3K9ac. Accordingly, loss-of-function mutations of TBX3 or low TBX3 expression levels are predictive of poor prognosis in HER2-positive breast cancer patients. Our work indicates that high levels of SIRT6 are indicative of poor prognosis and high risk of metastasis in HER2-positive breast cancer and suggests further investigation of TBX3 as a downstream target of SIRT6 and co-marker of poor-prognosis. Our results point to a breast cancer subtype-specific effect of SIRT6 and warrant future studies dissecting the mechanisms of SIRT6 regulation in different breast cancer subtypes.

Cohort analysis of novel SPAST variants in SPG4 patients and implementation of in vitro and in vivo studies to identify the pathogenic mechanism caused by splicing mutations.

Introduction: Pure hereditary spastic paraplegia (SPG) type 4 (SPG4) is caused by mutations of SPAST gene. This study aimed to analyze SPAST variants in SPG4 patients to highlight the occurrence of splicing mutations and combine functional studies to assess the relevance of these variants in the molecular mechanisms of the disease. Methods: We performed an NGS panel in 105 patients, in silico analysis for splicing mutations, and in vitro minigene assay. Results and discussion: The NGS panel was applied to screen 105 patients carrying a clinical phenotype corresponding to upper motor neuron syndrome (UMNS), selectively affecting motor control of lower limbs. Pathogenic mutations in SPAST were identified in 12 patients (11.42%), 5 missense, 3 frameshift, and 4 splicing variants. Then, we focused on the patients carrying splicing variants using a combined approach of in silico and in vitro analysis through minigene assay and RNA, if available. For two splicing variants (i.e., c.1245+1G>A and c.1414-2A>T), functional assays confirm the types of molecular alterations suggested by the in silico analysis (loss of exon 9 and exon 12). In contrast, the splicing variant c.1005-1delG differed from what was predicted (skipping exon 7), and the functional study indicates the loss of frame and formation of a premature stop codon. The present study evidenced the high splice variants in SPG4 patients and indicated the relevance of functional assays added to in silico analysis to decipher the pathogenic mechanism.

MiR-422a promotes adipogenesis via MeCP2 downregulation in human bone marrow mesenchymal stem cells.

Methyl-CpG binding protein 2 (MeCP2) is a ubiquitous transcriptional regulator. The study of this protein has been mainly focused on the central nervous system because alterations of its expression are associated with neurological disorders such as Rett syndrome. However, young patients with Rett syndrome also suffer from osteoporosis, suggesting a role of MeCP2 in the differentiation of human bone marrow mesenchymal stromal cells (hBMSCs), the precursors of osteoblasts and adipocytes. Here, we report an in vitro downregulation of MeCP2 in hBMSCs undergoing adipogenic differentiation (AD) and in adipocytes of human and rat bone marrow tissue samples. This modulation does not depend on MeCP2 DNA methylation nor on mRNA levels but on differentially expressed miRNAs during AD. MiRNA profiling revealed that miR-422a and miR-483-5p are upregulated in hBMSC-derived adipocytes compared to their precursors. MiR-483-5p, but not miR-422a, is also up-regulated in hBMSC-derived osteoblasts, suggesting a specific role of the latter in the adipogenic process. Experimental modulation of intracellular levels of miR-422a and miR-483-5p affected MeCP2 expression through direct interaction with its 3' UTR elements, and the adipogenic process. Accordingly, the knockdown of MeCP2 in hBMSCs through MeCP2-targeting shRNA lentiviral vectors increased the levels of adipogenesis-related genes. Finally, since adipocytes released a higher amount of miR-422a in culture medium compared to hBMSCs we analyzed the levels of circulating miR-422a in patients with osteoporosis-a condition characterized by increased marrow adiposity-demonstrating that its levels are negatively correlated with T- and Z-scores. Overall, our findings suggest that miR-422a has a role in hBMSC adipogenesis by downregulating MeCP2 and its circulating levels are associated with bone mass loss in primary osteoporosis.

Small molecule-induced epigenomic reprogramming of APL blasts leading to antiviral-like response and c-MYC downregulation.

Acute promyelocytic leukemia (APL) is an aggressive subtype of acute myeloid leukemia (AML) in which the PML/RARα fusion protein exerts oncogenic activities by recruiting repressive complexes to the promoter of specific target genes. Other epigenetic perturbations, as alterations of histone H3 lysine 9 trimethylation (H3K9me3), have been frequently found in AMLs and are associated with leukemogenesis and leukemia progression. Here, we characterized the epigenomic effects of maltonis, a novel maltol-derived molecule, in APL cells. We demonstrate that maltonis treatments induce a profound remodulation of the histone code, reducing global H3K9me3 signal and modulating other histone post-translational modifications. Transcriptomic and epigenomic analyses revealed that maltonis exposure induces changes of genes expression associated with a genomic redistribution of histone H3 lysine 4 trimethylation (H3K4me3) and lysine 27 acetylation (H3K27ac). Upregulation of interferon alpha and gamma response and downregulation of c-MYC target genes, in function of c-MYC reduced expression (monitored in all the hematopoietic neoplasms tested), represent the most significant modulated pathways. These data demonstrate the ability of maltonis to epigenetically reprogram the gene expression profile of APL cells, inducing an intriguing antiviral-like response, concomitantly with the downregulation of c-MYC-related pathways, thus making it an attractive candidate for antileukemic therapy.

Time makes histone H3 modifications drift in mouse liver.

To detect the epigenetic drift of time passing, we determined the genome-wide distributions of mono- and tri-methylated lysine 4 and acetylated and tri-methylated lysine 27 of histone H3 in the livers of healthy 3, 6 and 12 months old C57BL/6 mice. The comparison of different age profiles of histone H3 marks revealed global redistribution of histone H3 modifications with time, in particular in intergenic regions and near transcription start sites, as well as altered correlation between the profiles of different histone modifications. Moreover, feeding mice with caloric restriction diet, a treatment known to retard aging, reduced the extent of changes occurring during the first year of life in these genomic regions.

Decipher non-canonical SPAST splicing mutations with the help of functional assays in patients affected by spastic paraplegia 4 (SPG4).

Flowchart showing the molecular approach used to decipher the non-canonical splicing mutations.

Histone H3 Lysine 4 and 27 Trimethylation Landscape of Human Alzheimer's Disease.

BACKGROUND: Epigenetic remodeling is emerging as a critical process for both the onset and progression of Alzheimer's disease (AD), the most common form of neurodegenerative dementia. However, it is not clear to what extent the distribution of histone modifications is involved in AD. METHODS: To investigate histone H3 modifications in AD, we compared the genome-wide distributions of H3K4me3 and H3K27me3 in entorhinal cortices from severe sporadic AD patients and from age-matched healthy individuals of both sexes. RESULTS: AD samples were characterized by typical average levels and distributions of the H3K4me3 and H3K27me3 signals. However, AD patients showed a lower H3K4me3 and higher H3K27me3 signal, particularly in males. Interestingly, the genomic sites found differentially trimethylated at the H3K4 between healthy and AD samples involve promoter regions of genes belonging to AD-related pathways such as glutamate receptor signaling. CONCLUSIONS: The signatures of H3K4me3 and H3K27me3 identified in AD patients validate the role of epigenetic chromatin remodeling in neurodegenerative disease and shed light on the genomic adaptive mechanisms involved in AD.

The Current State of Chromatin Immunoprecipitation (ChIP) from FFPE Tissues.

Cancer cells accumulate epigenomic aberrations that contribute to cancer initiation and progression by altering both the genomic stability and the expression of genes. The awareness of such alterations could improve our understanding of cancer dynamics and the identification of new therapeutic strategies and biomarkers to refine tumor classification and treatment. Formalin fixation and paraffin embedding (FFPE) is the gold standard to preserve both tissue integrity and organization, and, in the last decades, a huge number of biological samples have been archived all over the world following this procedure. Recently, new chromatin immunoprecipitation (ChIP) techniques have been developed to allow the analysis of histone post-translational modifications (PTMs) and transcription factor (TF) distribution in FFPE tissues. The application of ChIP to genome-wide chromatin studies using real archival samples represents an unprecedented opportunity to conduct retrospective clinical studies thanks to the possibility of accessing large cohorts of samples and their associated diagnostic records. However, although recent attempts to standardize have been made, fixation and storage conditions of clinical specimens are still extremely variable and can affect the success of chromatin studies. The procedures introduced in the last few years dealt with this problem proponing successful strategies to obtain high-resolution ChIP profiles from FFPE archival samples. In this review, we compare the different FFPE-ChIP techniques, highlighting their strengths, limitations, common features, and peculiarities, as well as pitfalls and caveats related to ChIP studies in FFPE samples, in order to facilitate their application.

The Histone H3 K4me3, K27me3, and K27ac Genome-Wide Distributions Are Differently Influenced by Sex in Brain Cortexes and Gastrocnemius of the Alzheimer's Disease PSAPP Mouse Model.

BACKGROUND: Women represent the majority of Alzheimer's disease patients and show typical symptoms. Genetic, hormonal, and behavioral mechanisms have been proposed to explain sex differences in dementia prevalence. However, whether sex differences exist in the epigenetic landscape of neuronal tissue during the progression of the disease is still unknown. METHODS: To investigate the differences of histone H3 modifications involved in transcription, we determined the genome-wide profiles of H3K4me3, H3K27ac, and H3K27me3 in brain cortexes of an Alzheimer mouse model (PSAPP). Gastrocnemius muscles were also tested since they are known to be different in the two sexes and are affected during the disease progression. RESULTS: Correlation analysis distinguished the samples based on sex for H3K4me3 and H3K27me3 but not for H3K27ac. The analysis of transcription starting sites (TSS) signal distribution, and analysis of bounding sites revealed that gastrocnemius is more influenced than brain by sex for the three histone modifications considered, exception made for H3K27me3 distribution on the X chromosome which showed sex-related differences in promoters belonging to behavior and cellular or neuronal spheres in mice cortexes. CONCLUSIONS: H3K4me3, H3K27ac, and H3K27me3 signals are slightly affected by sex in brain, with the exception of H3K27me3, while a higher number of differences can be found in gastrocnemius.

A Large Family with p.Arg554His Mutation in ABCD1: Clinical Features and Genotype/Phenotype Correlation in Female Carriers.

X-linked adrenoleukodystrophy (X-ALD, OMIM #300100) is the most common peroxisomal disorder clinically characterized by two main phenotypes: adrenomyeloneuropathy (AMN) and the cerebral demyelinating form of X-ALD (cerebral ALD). The disease is caused by defects in the gene for the adenosine triphosphate (ATP)-binding cassette protein, subfamily D (ABCD1) that encodes the peroxisomal transporter of very-long-chain fatty acids (VLCFAs). The defective function of ABCD1 protein prevents ß-oxidation of VLCFAs, which thus accumulate in tissues and plasma, to represent the hallmark of the disease. As in many X-linked diseases, it has been routinely expected that female carriers are asymptomatic. Nonetheless, recent findings indicate that most ABCD1 female carriers become symptomatic, with a motor disability that typically appears between the fourth and fifth decade. In this paper, we report a large family in which affected males died during the first decade, while affected females develop, during the fourth decade, progressive lower limb weakness with spastic or ataxic-spastic gait, tetra-hyperreflexia with sensory alterations. Clinical and genetic evaluations were performed in nine subjects, eight females (five affected and three healthy) and one healthy male. All affected females were carriers of the c.1661G>A (p.Arg554His, rs201568579) mutation. This study strengthens the relevance of clinical symptoms in female carriers of ABCD1 mutations, which leads to a better understanding of the role of the genetic background and the genotype-phenotype correlation. This indicates the relevance to include ABCD1 genes in genetic panels for gait disturbance in women.

The dark side of histones: genomic organization and role of oncohistones in cancer.

BACKGROUND: The oncogenic role of histone mutations is one of the most relevant discovery in cancer epigenetics. Recurrent mutations targeting histone genes have been described in pediatric brain tumors, chondroblastoma, giant cell tumor of bone and other tumor types. The demonstration that mutant histones can be oncogenic and drive the tumorigenesis in pediatric tumors, led to the coining of the term "oncohistones." The first identified histone mutations were localized at or near residues normally targeted by post-translational modifications (PTMs) in the histone N-terminal tails and suggested a possible interference with histone PTMs regulation and reading. MAIN BODY: In this review, we describe the peculiar organization of the multiple genes that encode histone proteins, and the latter advances in both the identification and the biological role of histone mutations in cancer. Recent works show that recurrent somatic mutations target both N-terminal tails and globular histone fold domain in diverse tumor types. Oncohistones are often dominant-negative and occur at higher frequencies in tumors affecting children and adolescents. Notably, in many cases the mutations target selectively only some of the genes coding the same histone protein and are frequently associated with specific tumor types or, as documented for histone variant H3.3 in pediatric glioma, with peculiar tumors arising from specific anatomic locations. CONCLUSION: The overview of the most recent advances suggests that the oncogenic potential of histone mutations can be exerted, together with the alteration of histone PTMs, through the destabilization of nucleosome and DNA-nucleosome interactions, as well as through the disruption of higher-order chromatin structure. However, further studies are necessary to fully elucidate the mechanism of action of oncohistones, as well as to evaluate their possible application to cancer classification, prognosis and to the identification of new therapies.

A novel POLR3A genotype leads to leukodystrophy type-7 in two siblings with unusually late age of onset.

BACKGROUND: Leukodystrophies are familial heterogeneous disorders primarily affecting the white matter, which are defined as hypomyelinating or demyelinating based on disease severity as assessed at MRI. Recently, a group of clinically overlapping hypomyelinating leukodystrophies (HL) has been associated with mutations in RNA polymerase III enzymes (Pol III) subunits. CASE PRESENTATION: In this manuscript, we describe two Italian siblings carrying a novel POLR3A genotype. MRI imaging, genetic analysis, and clinical data led to diagnosing HL type 7. The female sibling, at the age of 34, is tetra-paretic and suffers from severe cognitive regression. She had a disease onset at the age of 19, characterized by slow and progressive cognitive impairment associated with gait disturbances and amenorrhea. The male sibling was diagnosed during an MRI carried out for cephalalgia at the age of 41. After 5 years, he developed mild cognitive impairment, dystonia with 4-limb hypotonia, and moderate dysmetria with balance and gait impairment. CONCLUSIONS: The present study provides the first evidence of unusually late age of onset in HL, describing two siblings with a novel POLR3A genotype which showed the first symptoms at the age of 41 and 19, respectively. This provides a powerful insight into clinical heterogeneity and genotype-phenotype correlation in POLR3A related HL.

Zn(ii) detection and biological activity of a macrocycle containing a bis(oxadiazole)pyridine derivative as fluorophore.

The synthesis, photochemical properties, biological effects and the X-ray crystal structure of a fluorescent polyamine macrocycle L are reported. L is a polyamine cyclophane macrocycle in which 2,6-bis(5-(2-methylphenyl)-1,3,4-oxadiazol-2-yl)pyridine (POXAPy) acts as a fluorescent sensor and the polyamine as a metal ion binding unit. L performs as a PET-mediated chemosensor, with a maximum emission wavelength close to 360 nm. This gives rise to a signal that is visible to the naked eye in the blue visible range. L is able to detect the Zn(ii) and Cd(ii) metal ions in an aqueous solution at pH = 7, with the coordination of the ions switching the emission ON through a CHEF effect. In contrast, paramagnetic metal ions like Cu(ii) and Ni(ii) completely quench the already low emission of L at this pH value. L affects the cell survival of a leukemic cellular model (U937) at micromolar concentrations with cell death starting after only 24 h of exposure; starting from a final concentration of 5 µM, L almost completely abrogates the survival of the leukemic cells over 72 h, with a mechanism that is compatible with a genomic DNA interaction.

Small extracellular vesicles deliver miR-21 and miR-217 as pro-senescence effectors to endothelial cells.

The role of epigenetics in endothelial cell senescence is a cutting-edge topic in ageing research. However, little is known of the relative contribution to pro-senescence signal propagation provided by microRNAs shuttled by extracellular vesicles (EVs) released from senescent cells. Analysis of microRNA and DNA methylation profiles in non-senescent (control) and senescent (SEN) human umbilical vein endothelial cells (HUVECs), and microRNA profiling of their cognate small EVs (sEVs) and large EVs demonstrated that SEN cells released a significantly greater sEV number than control cells. sEVs were enriched in miR-21-5p and miR-217, which target DNMT1 and SIRT1. Treatment of control cells with SEN sEVs induced a miR-21/miR-217-related impairment of DNMT1-SIRT1 expression, the reduction of proliferation markers, the acquisition of a senescent phenotype and a partial demethylation of the locus encoding for miR-21. MicroRNA profiling of sEVs from plasma of healthy subjects aged 40-100 years showed an inverse U-shaped age-related trend for miR-21-5p, consistent with senescence-associated biomarker profiles. Our findings suggest that miR-21-5p/miR-217 carried by SEN sEVs spread pro-senescence signals, affecting DNA methylation and cell replication.

Playing with Structural Parameters: Synthesis and Characterization of Two New Maltol-Based Ligands with Binding and Antineoplastic Properties.

Two maltol-based ligands, N,N'-bis((3-hydroxy-4-pyron-2-yl)methyl)-1,4-piperazine (L1) and N,N',N'-tris((3-hydroxy-4-pyron-2-yl)methyl)-N-methylethylendiamine (L2), were synthesized and characterized. L1 and L2, containing, respectively, two and three maltol units spaced by a diamine fragment, were designed to evaluate how biological and binding features are affected by structural modifications of the parent compound malten. The acid-base behavior and the binding properties towards transition, alkaline-earth (AE) and rare-earth (RE) cations in aqueous solution, studied by potentiometric, UV-Vis and NMR analysis, are reported along with biological studies on DNA and leukemia cells. Both ligands form stable complexes with Cu(II), Zn(II) and Co(II) that were studied as metallo-receptors for AE and RE at neutral pH. L1 complexes are more affected than L2 ones by hard cations, the L1-Cu(II) system being deeply affected by RE. The structural modifications altered the mechanism of action: L1 partially maintains the ability to induce structural alterations of DNA, while L2 provokes single strand (nicks) and to a lesser extent double strand breaks of DNA.

Dissecting Molecular Features of Gliomas: Genetic Loci and Validated Biomarkers.

Recently, several studies focused on the genetics of gliomas. This allowed identifying several germline loci that contribute to individual risk for tumor development, as well as various somatic mutations that are key for disease classification. Unfortunately, none of the germline loci clearly confers increased risk per se. Contrariwise, somatic mutations identified within the glioma tissue define tumor genotype, thus representing valid diagnostic and prognostic markers. Thus, genetic features can be used in glioma classification and guided therapy. Such copious genomic variabilities are screened routinely in glioma diagnosis. In detail, Sanger sequencing or pyrosequencing, fluorescence in-situ hybridization, and microsatellite analyses were added to immunohistochemistry as diagnostic markers. Recently, Next Generation Sequencing was set-up as an all-in-one diagnostic tool aimed at detecting both DNA copy number variations and mutations in gliomas. This approach is widely used also to detect circulating tumor DNA within cerebrospinal fluid from patients affected by primary brain tumors. Such an approach is providing an alternative cost-effective strategy to genotype all gliomas, which allows avoiding surgical tissue collection and repeated tumor biopsies. This review summarizes available molecular features that represent solid tools for the genetic diagnosis of gliomas at present or in the next future.

Chemopreventive Potential of Apple Pulp Callus Against Colorectal Cancer Cell Proliferation and Tumorigenesis.

This study focused on the evaluation of the chemopreventive potential of tissue in vitro culture of the "Mela Rosa Marchigiana" apple (MRM callus) that allows the amplification of secondary metabolites. The MRM pulp and MRM callus chemopreventive potential was evaluated in terms of antiproliferative activity, inhibition of tumorigenesis in soft agar cultures, cell cycle and western blotting analyses in CaCo2 and LoVo colon cancer cell lines and in JB6 promotion-sensitive (JB6 P+) cells. MRM callus induced a strong concentration-dependent inhibition of colon cancer cell proliferation and suppressed 12-o-tetra-decanoyl-phorbol-13-acetate-induced tumorigenesis of JB6 P+ cells in soft agar cultures. MRM callus inhibited the phosphorylation of JNK, p38, and eIF2alpha. Our data indicate that the MRM callus exerts a good antiproliferative and antitumorigenic potential through the MAP kinase inhibition and could provide natural compounds with chemopreventive properties.

Epigenomic profiling of archived FFPE tissues by enhanced PAT-ChIP (EPAT-ChIP) technology.

BACKGROUND: The introduction of pathology tissue-chromatin immunoprecipitation (PAT-ChIP), a technique allowing chromatin immunoprecipitation (ChIP) from formalin-fixed paraffin-embedded (FFPE) tissues, has extended the application of chromatin studies to clinical patient samples. However, extensive crosslinking introduced during routine tissue fixation of clinical specimens may hamper the application of PAT-ChIP to genome-wide studies (PAT-ChIP-Seq) from archived tissue samples. The reduced efficiency in chromatin extraction from over-fixed formalin archival samples is the main hurdle to overcome, especially when low abundant epigenetic marks (e.g., H3K4me3) are investigated. RESULTS: We evaluated different modifications of the original PAT-ChIP protocol to improve chromatin isolation from FFPE tissues. With this aim, we first made extensive usage of a normal human colon specimen fixed at controlled conditions (24 h, 48 h, and 72 h) to mimic the variability of tissue fixation that is most frequently found in archived samples. Different conditions of chromatin extraction were tested applying either diverse sonication protocols or heat-mediated limited reversal of crosslinking (LRC). We found that, if compared with canonical PAT-ChIP protocol, LRC strongly increases chromatin extraction efficiency, especially when 72-h fixed FFPE samples are used. The new procedure, that we named enhanced PAT-ChIP (EPAT-ChIP), was then applied at genome-wide level using an archival sample of invasive breast carcinoma to investigate H3K4me3, a lowly abundant histone modification, and H3K27me3 and H3K27ac, two additional well-known histone marks. CONCLUSIONS: EPAT-ChIP procedure improves the efficiency of chromatin isolation from FFPE samples allowing the study of long time-fixed specimens (72 h), as well as the investigation of low distributed epigenetic marks (e.g., H3K4me3) and the analysis of multiple histone marks from low amounts of starting material. We believe that EPAT-ChIP will facilitate the application of chromatin studies to archived pathology samples, thus contributing to extend the current understanding of cancer epigenomes and enabling the identification of clinically useful tumor biomarkers.

Effects of Fifty-Hertz Electromagnetic Fields on Granulocytic Differentiation of ATRA-Treated Acute Promyelocytic Leukemia NB4 Cells.

BACKGROUND/AIMS: Life on Earth is constantly exposed to electromagnetic fields (EMFs) and the effects induced by EMFs on biological systems have been extensively studied producing different and sometimes contradictory results. Extremely low-frequency electromagnetic fields (ELF-EMFs) have shown to play a role in regulating cell proliferation and differentiation, although how EMFs influence these processes remains unclear. Human acute promyelocytic leukemia (APL) cells are characterized by the arrest of differentiation at the promyelocytic stage due to epigenetic perturbations induced by PML/RARα fusion protein (Promyelocytic Leukemia protein - PML/Retinoic Acid Receptor alpha - RARα). Therapeutic administration of all-trans retinoic acid (ATRA) re-establishes the leukemogenic mechanism re-inducing the normal differentiation processes. METHODS: We studied the effects of ELF-EMFs (50 Hz, 2 mT) on the ATRA-mediated granulocytic differentiation process of APL NB4 cells (a cell line established from the bone marrow of a patient affected by the acute promyelocytic leukemia) by monitoring cellular proliferation and morphology, nitrob lue tetrazolium (NBT) reduction and the expression of differentiation surface markers. Finally, we investigated mechanisms focusing on reactive oxygen species (ROS) generation and related molecular pathways. RESULTS: ELF-EMF exposure decreases cellular proliferation potential and helps ATRA-treated NB4 cells to mature. Furthermore, the analysis of ROS production and the consequent extracellular signal regulated kinases (ERK1/2) phosphorylation suggest that a changed intracellular oxidative balance may influence the biological effects of ELF-EMFs. CONCLUSIONS: These results indicate that the exposure to ELF-EMF promotes ATRA-induced granulocytic differentiation of APL cells.

miR-494-3p is a novel tumor driver of lung carcinogenesis.

Lung cancer is the leading cause of tumor-related death worldwide and more efforts are needed to elucidate lung carcinogenesis. Here we investigated the expression of 641 miRNAs in lung tumorigenesis in a K-Ras(+/LSLG12Vgeo);RERTn(ert/ert) mouse model and 113 human tumors. The conserved miRNA cluster on chromosome 12qF1 was significantly and progressively upregulated during murine lung carcinogenesis. In particular, miR-494-3p expression was correlated with lung cancer progression in mice and with worse survival in lung cancer patients. Mechanistically, ectopic expression of miR-494-3p in A549 lung cancer cells boosted the tumor-initiating population, enhanced cancer cell motility, and increased the expression of stem cell-related genes. Importantly, miR-494-3p improved the ability of A549 cells to grow and metastasize in vivo, modulating NOTCH1 and PTEN/PI3K/AKT signaling.Overall, these data identify miR-494-3p as a key factor in lung cancer onset and progression and possible therapeutic target.