Stearoyl CoA Desaturase-1 Silencing in Glioblastoma Cells: Phospholipid Remodeling and Cytotoxicity Enhanced upon Autophagy Inhibition.

Modulation of lipid metabolism is a well-established cancer hallmark, and SCD1 has been recognized as a key enzyme in promoting cancer cell growth, including in glioblastoma (GBM), the deadliest brain tumor and a paradigm of cancer resistance. The central goal of this work was to identify, by MS, the phospholipidome alterations resulting from the silencing of SCD1 in human GBM cells, in order to implement an innovative therapy to fight GBM cell resistance. With this purpose, RNAi technology was employed, and low serum-containing medium was used to mimic nutrient deficiency conditions, at which SCD1 is overexpressed.

MiR-200c-based metabolic modulation in glioblastoma cells as a strategy to overcome tumor chemoresistance.

Glioblastoma (GB) is the most aggressive and common form of primary brain tumor characterized by fast proliferation, high invasion and resistance to current standard treatment. The average survival rate post-diagnosis is 14.6 months, despite the aggressive standard post-surgery radiotherapy concomitant with chemotherapy with temozolomide (TMZ).

Improving pollutants environmental risk assessment using a multi model toxicity determination with in vitro, bacterial, animal and plant model systems: The case of the herbicide alachlor.

Several environmental pollutants, including pesticides, herbicides and persistent organic pollutants play an important role in the development of chronic diseases. However, most studies have examined environmental pollutants toxicity in target organisms or using a specific toxicological test, losing the real effect throughout the ecosystem. In this sense an integrative environmental risk of pollutants assessment, using different model organisms is necessary to predict the real impact in the ecosystem and implications for target and non-target organisms.

Downregulation of long non-protein coding RNA MVIH impairs glioblastoma cell proliferation and invasion through an miR-302a-dependent mechanism.

Glioblastoma (GB) is the most frequent and malignant type of brain tumor, for which no effective therapy exists. The high proliferative and invasive nature of GB, as well as its acquired resistance to chemotherapy, makes this type of cancer extremely lethal shortly after diagnosis. Long non-protein coding RNAs (lncRNA) are a class of regulatory RNAs whose levels can be dysregulated in the context of diseases, unbalancing several physiological processes.

Differentiation of glioblastoma stem cells promoted by miR-128 or miR-302a overexpression enhances senescence-associated cytotoxicity of axitinib.

Despite the intense global efforts towards an effective treatment of glioblastoma (GB), current therapeutic options are unsatisfactory with a median survival time of 12-15 months after diagnosis, which has not improved significantly over more than a decade. The high tumoral heterogeneity confers resistance to therapies, which has hindered a successful clinical outcome, GB remaining among the deadliest cancers. A hallmark of GB is its high recurrence rate, which has been attributed to the presence of a small subpopulation of tumor cells called GB stem-like cells (GSC).

Lauroylated Histidine-Enriched S4-PV Peptide as an Efficient Gene Silencing Mediator in Cancer Cells.

Purpose: This study aimed to endow the cell-penetrating peptide (CPP) S4-PV with adequate features towards a safe and effective application in cancer gene therapy.

Methods: Peptide/siRNA complexes were prepared with two new derivatives of the CPP S4-PV, which combine a lauroyl group attached to the N- or C-terminus with a histidine-enrichment in the N-terminus of the S4-PV peptide, being named C12-H-S4-PV and H-S4-PV-C12, respectively. Physicochemical characterization of siRNA complexes was performed and their cytotoxicity and efficiency to mediate siRNA delivery and gene silencing in cancer cells were assessed in the absence and presence of serum.

Lysosomal Storage Disease-Associated Neuropathy: Targeting Stable Nucleic Acid Lipid Particle (SNALP)-Formulated siRNAs to the Brain as a Therapeutic Approach.

More than two thirds of Lysosomal Storage Diseases (LSDs) present central nervous system involvement. Nevertheless, only one of the currently approved therapies has an impact on neuropathology. Therefore, alternative approaches are under development, either addressing the underlying enzymatic defect or its downstream consequences.

Glucosylceramide synthase silencing combined with the receptor tyrosine kinase inhibitor axitinib as a new multimodal strategy for glioblastoma.

A great deal of evidence revealing that lipid metabolism is drastically altered during tumorigenesis has been accumulated. In this work, glucosylceramide synthase (GCS) was targeted, using RNA interference technology (siRNAs), in U87 and DBTRG human glioblastoma (GBM) cells, as in both cell types GCS showed to be overexpressed with respect to normal human astrocytes. The efficacy of a combined therapy to tackle GBM, allying GCS silencing to the new generation chemotherapeutics sunitinib and axitinib, or to the alkylating drugs etoposide and temozolomide, is evaluated here for the first time.

Acylation of the S4-PV cell-penetrating peptide as a means of enhancing its capacity to mediate nucleic acid delivery: Relevance of peptide/lipid interactions.

Background: Cell-penetrating peptides (CPPs) have been extensively exploited in gene therapy approaches as vectors for intracellular delivery of bioactive molecules. The ability of CPPs to be internalized into cells and their capacity to complex nucleic acids depend on their molecular structure, both primary and secondary, namely regarding hydrophobicity/hydrophilicity. CPP acylation has been used as a strategy to improve this structural feature.

Multimodal highly fluorescent-magnetic nanoplatform to target transferrin receptors in cancer cells.

Background: Site-specific multimodal nanoplatforms with fluorescent-magnetic properties have great potential for biological sciences. For this reason, we developed a multimodal nanoprobe (BNPs-Tf), by covalently conjugating an optical-magnetically active bimodal nanosystem, based on quantum dots and iron oxide nanoparticles, with the human holo-transferrin (Tf).

Methods: The Tf bioconjugation efficiency was evaluated by the fluorescence microplate assay (FMA) and the amount of Tf immobilized on BNPs was quantified by fluorescence spectroscopy.

Resveratrol stimulates the metabolic reprogramming of human CD4 T cells to enhance effector function.

The polyphenol resveratrol activates the deacetylase Sirt1, resulting in various antioxidant, chemoprotectant, neuroprotective, cardioprotective, and anti-inflammatory properties. We found that at high concentrations of resveratrol, human CD4 T cells showed defective antigen receptor signaling and arrest at the G stage of the cell cycle, whereas at low concentrations, cells were readily activated and exhibited enhanced Sirt1 deacetylase activity. Nevertheless, low-dose resveratrol rapidly stimulated genotoxic stress in the T cells, which resulted in engagement of a DNA damage response pathway that depended on the kinase ATR [ataxia telangiectasia-mutated (ATM) and Rad3-related], but not ATM, and subsequently in premitotic cell cycle arrest.

High-throughput screening uncovers miRNAs enhancing glioblastoma cell susceptibility to tyrosine kinase inhibitors.

Glioblastoma (GBM) is a deadly and therapy resistant malignant brain tumour, characterized by an aggressive and diffuse growth pattern, which prevents complete surgical resection. Despite advances in the identification of genomic and molecular alterations that fuel the tumour, average patient survival post-diagnosis remains very low (∼14.6-months).

MicroRNA deregulation and chemotaxis and phagocytosis impairment in Alzheimer's disease.

Introduction: Mononuclear phagocytes play a critical role during Alzheimer's disease (AD) pathogenesis due to their contribution to innate immune responses and amyloid beta (Aβ) clearance mechanisms.

Methods: Blood-derived monocytes (BDMs) and monocyte-derived macrophages (MDMs) were isolated from blood of AD, mild cognitive impairment (MCI) patients, and age-matched healthy controls for molecular and phenotypic comparisons.

Results: The chemokine/chemokine receptor CCL2/CCR2 axis was impaired in BDMs from AD and MCI patients, causing a deficit in cell migration.

Enhancing glioblastoma cell sensitivity to chemotherapeutics: A strategy involving survivin gene silencing mediated by gemini surfactant-based complexes.

Glioblastoma (GBM), the highest grade astrocytoma, is one of the most aggressive and challenging cancers to treat. The standard treatment is usually limited due to the intrinsic resistance of GBM to chemotherapy and drug non-specific effects. Therefore, new therapeutic strategies need to be developed to target tumor cells, sparing healthy tissues.

CdTe quantum dots as fluorescent probes to study transferrin receptors in glioblastoma cells.

Background: Overexpression of transferrin receptors (TfRs), which are responsible for the intracellular uptake of ferric transferrin (Tf), has been described in various cancers. Although molecular biology methods allow the identification of different types of receptors in cancer cells, they do not provide features about TfRs internalization, quantification and distribution on cell surface. This information can, however, be accessed by fluorescence techniques.

Role of microRNAs in the regulation of innate immune cells under neuroinflammatory conditions.

MiRNAs are short, evolutionary conserved noncoding RNA molecules with the ability to control the magnitude of inflammation. The immunosuppressive nature of the brain is sustained by miRNA-dependent regulation of microglial cells, which become activated under neuroinflammatory conditions, such as brain injury and neurodegeneration. The pro-inflammatory and suppressive role of the most studied neuroimmune miRNAs, miR-155 and miR-146a, has been recently challenged.

MiRNA-21 silencing mediated by tumor-targeted nanoparticles combined with sunitinib: A new multimodal gene therapy approach for glioblastoma.

Malignant brain tumors, including glioblastoma (GBM), are among the most lethal human cancers, due to their tremendous invasive capacity and limited therapeutic options. Despite remarkable advances in cancer theranostics, which resulted in significant improvement of clinical outcomes, GBM relapse is very frequent and patient survival remains under one year. The elucidation of the role of abnormally-expressed miRNAs in different steps of GBM pathogenesis and in tumor resistance to therapy paved the way for the development of new miRNA-based therapeutic approaches targeting this disease, aiming at increasing specific tumor cell killing and, ultimately, cancer eradication.

Gemini surfactants mediate efficient mitochondrial gene delivery and expression.

Gene delivery targeting mitochondria has the potential to transform the therapeutic landscape of mitochondrial genetic diseases. Taking advantage of the nonuniversal genetic code used by mitochondria, a plasmid DNA construct able to be specifically expressed in these organelles was designed by including a codon, which codes for an amino acid only if read by the mitochondrial ribosomes. In the present work, gemini surfactants were shown to successfully deliver plasmid DNA to mitochondria.

MicroRNAs in glioblastoma: role in pathogenesis and opportunities for targeted therapies.

Glioblastoma (GBM) is among the most lethal human cancers, being generally characterized by rapid diffuse and infiltrative growth and high level of cellular heterogeneity associated with therapeutic resistance. Despite remarkable advances in cancer theranostics, which resulted in significant improvement of clinical outcomes, patient survival remains under one year. In recent years, considerable progress has been made in understanding the role of small non-coding RNAs, designated microRNAs, in the pathogenesis of GBM.

New serine-derived gemini surfactants as gene delivery systems.

Gemini surfactants have been extensively used for in vitro gene delivery. Amino acid-derived gemini surfactants combine the special aggregation properties characteristic of the gemini surfactants with high biocompatibility and biodegradability. In this work, novel serine-derived gemini surfactants, differing in alkyl chain lengths and in the linker group bridging the spacer to the headgroups (amine, amide and ester), were evaluated for their ability to mediate gene delivery either per se or in combination with helper lipids.

Increased gene delivery efficiency and specificity of a lipid-based nanosystem incorporating a glycolipid.

Hepatocellular carcinoma (HCC) is the third most common cause of death related to cancer diseases worldwide. The current treatment options have many limitations and reduced success rates. In this regard, advances in gene therapy have shown promising results in novel therapeutic strategies.

Bis-quaternary gemini surfactants as components of nonviral gene delivery systems: a comprehensive study from physicochemical properties to membrane interactions.

Gemini surfactants have been successfully used as components of gene delivery systems. In the present work, a family of gemini surfactants, represented by the general structure [CmH2m+1(CH3)2N(+)(CH2)sN(+)(CH3)2CmH2m+1]2Br(-), or simply m-s-m, was used to prepare cationic gene carriers, aiming at their application in transfection studies. An extensive characterization of the gemini surfactant-based complexes, produced with and without the helper lipids cholesterol and DOPE, was carried out in order to correlate their physico-chemical properties with transfection efficiency.

MicroRNA modulation combined with sunitinib as a novel therapeutic strategy for pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and mortal cancer, characterized by a set of known mutations, invasive features, and aberrant microRNA expression that have been associated with hallmark malignant properties of PDAC. The lack of effective PDAC treatment options prompted us to investigate whether microRNAs would constitute promising therapeutic targets toward the generation of a gene therapy approach with clinical significance for this disease. In this work, we show that the developed human serum albumin-1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine:cholesterol/anti-microRNA oligonucleotides (+/-) (4/1) nanosystem exhibits the ability to efficiently deliver anti-microRNA oligonucleotides targeting the overexpressed microRNAs miR-21, miR-221, miR-222, and miR-10 in PDCA cells, promoting an almost complete abolishment of microRNA expression.

Specific and efficient gene delivery mediated by an asialofetuin-associated nanosystem.

Gene therapy is considered a promising approach for the treatment of hepatocellular carcinoma (HCC). In this regard, the main goal of this work was to develop a specific and efficient gene delivery nanosystem to HCC based on 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine:cholesterol cationic liposomes and asialofetuin (ASF), a specific ligand to the asialoglycoprotein receptor (ASGP-R) that is overexpressed in HCC. Our results show that association of ASF to lipoplexes promotes a substantial increase in their biological activity in HCC cells, not only in vitro, but also in an animal model.