283 research outputs found

    Cannabidiol stimulates AML-1a-dependent glial differentiation and inhibits glioma stem-like cells proliferation by inducing autophagy in a TRPV2-dependent manner

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    Glioma stem-like cells (GSCs) correspond to a tumor cell subpopulation, involved in glioblastoma multiforme (GBM) tumor ini- tiation and acquired chemoresistance. Currently, drug-induced differentiation is considered as a promising approach to eradi- cate this tumor-driving cell population. Recently, the effect of cannabinoids (CBs) in promoting glial differentiation and inhibiting gliomagenesis has been evidenced. Herein, we demonstrated that cannabidiol (CBD) by activating transient receptor potential vanilloid-2 (TRPV2) triggers GSCs differentiation activating the autophagic process and inhibits GSCs proliferation and clonogenic capability. Above all, CBD and carmustine (BCNU) in combination overcome the high resistance of GSCs to BCNU treatment, by inducing apoptotic cell death. Acute myeloid leukemia (Aml-1) transcription factors play a pivotal role in GBM proliferation and differentiation and it is known that Aml-1 control the expression of several nociceptive receptors. So, we evaluated the expression levels of Aml-1 spliced variants (Aml-1a, b and c) in GSCs and during their differentiation. We found that Aml-1a is upregulated during GSCs differentiation, and its downregulation restores a stem cell phenotype in differ- entiated GSCs. Since it was demonstrated that CBD induces also TRPV2 expression and that TRPV2 is involved in GSCs differ- entiation, we evaluated if Aml-1a interacted directly with TRPV2 promoters. Herein, we found that Aml-1a binds TRPV2 promoters and that Aml-1a expression is upregulated by CBD treatment, in a TRPV2 and PI3K/AKT dependent manner. Alto- gether, these results support a novel mechanism by which CBD inducing TRPV2-dependent autophagic process stimulates Aml-1a-dependent GSCs differentiation, abrogating the BCNU chemoresistance in GSCs

    A combined microRNA-based targeted therapeutic approach to eradicate glioblastoma stem-like cells

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    A minor population of glioblastoma stem-like cells (GSCs) has been implicated in the relapse and resistance of glioblastoma to therapeutic treatments. Based on knowledge of the involvement of multiple microRNAs in GSC propagation, we designed a combinational approach to target the GSC population with multiple miRNA-based therapeutics. As carriers for the targeted delivery we took advantage of two aptamers that bind to, and inhibit, the receptor tyrosine kinases, Axl and PDGFRβ. We showed that the aptamer conjugates are transported through an in vitro blood-brain barrier (BBB) model. Furthermore, combining miR-137 and antimiR-10b synergizes with the receptor inhibitory function of aptamer carriers and prevents GSC expansion. Results highlighted the potential of combining multifunctional RNA-based therapeutics for selective targeting of GSCs and offer a proof of principle strategy to potentially fulfill the still unmet need for effective and safe treatment of glioma

    RYK promotes the stemness of glioblastoma cells via the WNT/ \u3b2-catenin pathway

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    Glioblastoma multiforme (GBM) is characterized by a strong self-renewal potential and a poor differentiation state. Since receptor-like tyrosine kinase (RYK) activates the WNT/\u3b2-catenin pathway essential for cancer stem cell maintenance, we evaluated its contribution in conferring stemness to GBM cells. Here, we report that Ryk (related-to-receptor tyrosine kinase), an atypical tyrosine kinase receptor, is upregulated in samples from GBM patients as well as in GSCs. Ryk overexpression confers stemness properties to GBM cells through the modulation of the canonical Wnt signaling and by promoting the activation of pluripotency-related transcription factor circuitry and neurosphere formation ability. In contrast, siRNA-mediated knockdown of Ryk expression suppresses this stem-like phenotype. Rescue experiments reveal that stemness-promoting activity of Ryk is attributable, at least in part, to \u3b2-catenin stabilization. Furthermore, Ryk overexpression improves cell motility and anchorage independent cell growth. Taken together, our findings demonstrate that Ryk promotes stem cell-like and tumorigenic features to glioma cells its essential for the maintenance of GSCs and could be a target of novel therapies

    Highly Potent and Selective Dopamine D4 Receptor Antagonists Potentially Useful for the Treatment of Glioblastoma

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    To better understand the role of dopamine D-4 receptor (D4R) in glioblastoma (GBM), in the present paper, new ligands endowed with high affinity and selectivity for D4R were discovered starting from the brain penetrant and D4R selective lead compound 1-(3-(4-phenylpiperazin-1-yl)propyl)-3,4-dihydroquinolin-2(1H)-one (6). In particular, the D4R antagonist 24, showing the highest affinity and selectivity over D2R and D3R within the series (D-2/D-4 = 8318, D-3/D-4 = 3715), and the biased ligand 29, partially activating D4R G(i)-/G(o)-protein and blocking beta-arrestin recruitment, emerged as the most interesting compounds. These compounds, evaluated for their GBM antitumor activity, induced a decreased viability of GBM cell lines and primary GBM stem cells (GSC#83), with the maximal efficacy being reached at a concentration of 10 mu M. Interestingly, the treatment with both compounds 24 and 29 induced an increased effect in reducing the cell viability with respect to temozolomide, which is the first-choice chemotherapeutic drug in GBM

    Parasitism of the mite Acarophenax lacunatus on Tribolium castaneum

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    O objetivo deste trabalho foi avaliar o potencial de parasitismo do ácaro Acarophenax lacunatus (Cross & Krantz) sobre Tribolium castaneum (Herbst). As unidades experimentais consistiram de placas de Petri contendo 25 g de grãos de trigo infestados com 20 adultos desse coleóptero. Depois de sete dias da infestação, os ácaros foram introduzidos em diferentes densidades (0, 2, 4, 6, 8 e 10 fêmeas) nas placas de Petri. O aumento da densidade do ácaro acarretou aumento linear do parasitismo, com conseqüente redução das populações desse inseto. É possível utilizar esse ácaro no controle biológico de T. castaneum.The objective of this work was to assess the parasitism potential of Acarophenax lacunatus (Cross & Krantz) on Tribolium castaneum (Herbst). The experimental units encompassed Petri dishes containing 25 g of wheat infested with 20 adults of this beetle species. After seven days of infestation, different mite densities (0, 2, 4, 6, 8 and 10 females) were inoculated into the Petri dishes. The increase in mite density led to a linear increase in parasitism, and a consequent reduction in populations of this insect. It is possible to use this mite species in the biological control of T. castaneum

    Olfactory groove meningioma: report of 99 cases surgically treated at the Catholic University School of Medicine, Rome

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    OBJECTIVE: We reviewed our series of olfactory groove meningiomas (OGMs) with the aim to relate the surgical approach with outcome and to define clinical and pathologic predictors of prognosis. METHODS: Ninety-nine patients who underwent 113 craniotomies at our Institution between 1984 and 2010 were entered this study. The relationship between surgical approach (bifrontal, fronto-orbito-basal, and pterional) and either tumor diameter, extent of tumor resection, complication rate, need of reoperation, and Karnofsky Performance Status (KPS) was analyzed. The impact of age ( 64 70 vs. > 70 years), sex, tumor diameter (< 6 vs. 65 6 cm), pre- and postoperative KPS (< 80 vs. 65 80), Simpson grade (I-II vs. III-IV), and World Health Organization (WHO) histologic grade (I vs. II-III) on survival was assessed. Kaplan-Meier survival curves were plotted and differences in survival between groups of patients were compared. A multivariate analysis adjusted for age, pre- and postoperative KPS, Simpson grade, tumor diameter, and WHO histologic grade also was performed. RESULTS: The fronto-orbito-basal approach (n = 22) allowed a significantly greater percentage of Simpson I-II removals than the bifrontal (n = 70) and pterional approach (n = 21) (P = 0.0354 and P = 0.0485, respectively). The risk of life-threatening complications trended to be lower in patients operated upon either via the fronto-orbito-basal and via the pterional approach than in those treated via the bifrontal approach. Retraction-related brain swelling did not occur in any case after the fronto-orbito-basal approach (P = 0.0384); however, this approach was associated with a greater rate of cerebrospinal fluid leak (P = 0.0011). Among prognostic factors, age 64 70 years (P = 0.0044), tumor diameter <6 cm (P = 0.0455), pre- and postoperative KPS 65 80 (both P < 0.0001), Simpson grade I-II (P = 0.0096), and WHO histologic grade I (P = 0.0112) were significantly associated with longer overall survival. Age (P = 0.0393) and WHO histologic grade (P = 0.0418) emerged as independent prognostic factors for overall survival on multivariate analysis. CONCLUSION: In the largest series of OGMs published to date, the bifrontal approach was associated with a greater risk of life-threatening complications compared with the lateral pterional and fronto-orbito-basal approaches. The fronto-orbito-basal approach provided greater chances of total tumor removal than the bifrontal and pterional approaches. Two independent factors for overall survival of patients with OGM were identified, namely age and WHO grade
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