Metformin-Derived Hybrid Molecules for Glioblastoma Treatment

International audienceGlioblastoma is the most common cerebral tumor in adults. The median survival of glioblastoma patients is 12 months. Metformin is a biguanide used as a standard clinical drug for the treatment of type 2 diabetes. Recently, several studies revealed that the risk of cancer development was significantly reduced for diabetic patients treated with metformin compared to those treated with insulin or sulfonylureas [1]. Even if metformin acts as an antitumoral agent, it is a nontoxic molecule with IC50 around 10 mM in cancer cells. In cancer research, naturally occurring phenolic acids are well known to be useful antioxidant agents and allow the inhibition of the migration and adhesion of cancer cells [2]. Moreover, a recent study [3] on nitrones combined with phenolic acids has shown that phenolic acids keep their antioxidant properties even if they are coupled with another molecule. The purpose of this study is to design new molecules combining metformin and a phenolic acid to improve the cytotoxicity on cancer cells. A series of hybrid molecules was then synthesized. For each molecule, IC50 on glioblastoma cell lines (U87 and U251) and on human dermal fibroblasts was tested. After this first screening, the mechanisms through which the best hybrid molecules act on cancer cells were studied and compared with those of metformin. Finally, the study of cytotoxicity on cancer stems cells of glioblastoma, GBM6, and GBM9 revealed that metformin-derived molecules may also restrict the growth of stem cells. As cancer stem cells are one of the causes of tumor resistance [4], metformin hybrid molecules may become a novel therapeutic option to treat glioblastoma. References 1. Zi, F.; Zi, H.; Li, Y.; He, J.; Shi, Q.; Cai, Z. Metformin and cancer: An existing drug for cancer prevention and therapy. Oncology Lett. 2018, 15, 683-690. 2. Bouzaiene, N.N.; Jaziri, S.K.; Kovacic, H.; Chekir-Ghedira, L.; Ghedira, K.; Luis, J. The effects of caffeic, coumaric and ferulic acids on proliferation, superoxide production, adhesion and migration of human tumor cells in vitro. Eur. J. Pharmacol. 2015, 766, 99-105. 3. Cassien, M.; Petrocchi, C.; Thétiot-Laurent, S.; Robin, M.; Ricquebourg, E.; Kandouli, C.; Asteian, A.; Rockenbauer A.; Mercier, A.; Culcasi, M.; et al. On the vasoprotective mechanisms underlying novel β-phosphorylated nitrones: Focus on free radical characterization, scavenging and NO-donation in a biological model of oxidative stress. Eur. J. Med. Chem. 2016, 119, 197-217

Gq-coupled Purinergic Receptors Inhibit Insulin-like Growth Factor-I/Phosphoinositide 3-Kinase Pathway-dependent Keratinocyte Migration

After skin wound, released growth factors and extracellular nucleotides regulate the different phases of healing, including re-epithelialization. Here, we show that, in keratinocytes, purinergic P2Y2 receptors inhibit the motogenic IGF-I/PI3K pathway. Therefore, extracellular nucleotides may play key roles during skin remodelling after wound

Managing intensive care units: Make LOVE, not war!

International audienceOBJECTIVE: Describe a program set up in a French intensive care unit (ICU) aimed at improving communication inside the team and communication information given to patients and their relatives; explain how those actions can improve communication inside the ICU and ultimately why it could improve patient's outcome. DESIGN AND METHODS: Position paper. INTERVENTION: Progressive implementation of multifaceted quality improvement program. RESULTS: The program Leadership, Ownership, Values, and Evaluation (LOVE) was developed over 10 years. It was usually well accepted by the members of the team, patients, and relatives, in particular the 24-hour visiting program that was prospectively evaluated. Information and decisions were shared with the patients or more often with the relatives, who became for some of them really "part of the team." Additional actions such as participation to some of the simplest cares by the families are under investigation. A prospective evaluation of such programs, although difficult to perform, remains probably necessary. CONCLUSION: Quality of life within the ICU is based on many factors including a strong and positive leadership, an absolute respect of individuals, and a rigorous evaluation of quality of care, which could influence heavily the quality of life in the ICU for patients, relatives, and health care professionals and facilitate team work. Whether this could really influence outcome remains to be demonstrated

Overexpression of a Novel Noxo1 Mutant Increases Ros Production and Noxo1 Relocalisation

Noxo1, the organizing element of the Nox1-dependent NADPH oxidase complex responsible for producing reactive oxygen species, has been described to be degraded by the proteasome. We mutated a D-box in Noxo1 to express a protein with limited degradation and capable of maintaining Nox1 activation. Wild-type (wt) and mutated Noxo1 (mut1) proteins were expressed in different cell lines to characterize their phenotype, functionality, and regulation. Mut1 increases ROS production through Nox1 activity affects mitochondrial organization and increases cytotoxicity in colorectal cancer cell lines. Unexpectedly the increased activity of Noxo1 is not related to a blockade of its proteasomal degradation since we were unable in our conditions to see any proteasomal degradation either for wt or mut1 Noxo1. Instead, D-box mutation mut1 leads to an increased translocation from the membrane soluble fraction to a cytoskeletal insoluble fraction compared to wt Noxo1. This mut1 localization is associated in cells with a filamentous phenotype of Noxo1, which is not observed with wt Noxo1. We found that mut1 Noxo1 associates with intermediate filaments such as keratin 18 and vimentin. In addition, Noxo1 D-Box mutation increases Nox1-dependent NADPH oxidase activity. Altogether, Nox1 D-box does not seem to be involved in Noxo1 degradation but rather related to the maintenance of the Noxo1 membrane/cytoskeleton balance

Gα(q/11)-coupled P2Y 2 nucleotide receptor inhibits human keratinocyte spreading and migration

International audienceReepithelialization is a critical step in wound healing. It is initiated by keratinocyte migration at the wound edges. After wounding, extracellular nucleotides are released by keratinocytes and other skin cells. Here, we report that activation of P2Y2 nucleotide receptor by ATP/UTP inhibits keratinocyte cell spreading and induces lamellipodium withdrawal. Kymography analysis demonstrates that these effects correlate with a durable decrease of lamellipodium dynamics. P2Y2 receptor activation also induces a dramatic dismantling of the actin network, the loss of alpha3 integrin expression at the cell periphery, and the dissolution of focal contacts as indicated by the alteration of alpha(v) integrins and focal contact protein distribution. In addition, activation of P2Y2R prevents growth factor-induced phosphorylation of Erk(1,2) and Akt/PkB. The use of a specific pharmacological inhibitor (YM-254890), the depletion of G alpha(q/11) by siRNA, or the expression of a constitutively active G alpha(q/11) mutant (Q209L) show that activation of G alpha(q/11) is responsible for these ATP/UTP-induced effects. Finally, we report that ATP delays growth factor-induced wound healing of keratinocyte monolayers. Collectively, these findings provide evidence for a unique and important role for extracellular nucleotides as efficient autocrine/paracrine regulators of keratinocyte shape and migration during wound healing

Tau Regulates Glioblastoma Progression, 3D Cell Organization, Growth and Migration via the PI3K-AKT Axis

International audienceThe Microtubule-Associated Protein Tau is expressed in several cancers, including low-grade gliomas and glioblastomas. We have previously shown that Tau is crucial for the 2D motility of several glioblastoma cell lines, including U87-MG cells. Using an RNA interference (shRNA), we tested if Tau contributed to glioblastoma in vivo tumorigenicity and analyzed its function in a 3D model of multicellular spheroids (MCS). Tau depletion significantly increased median mouse survival in an orthotopic glioblastoma xenograft model. This was accompanied by the inhibition of MCS growth and cell evasion, as well as decreased MCS compactness, implying N-cadherin mislocalization. Intracellular Signaling Array analysis revealed a defective activation of the PI3K/AKT pathway in Tau-depleted cells. Such a defect in PI3K/AKT signaling was responsible for reduced MCS growth and cell evasion, as demonstrated by the inhibition of the pathway in control MCS using LY294002 or Perifosine, which did not significantly affect Tau-depleted MCS. Finally, analysis of the glioblastoma TCGA dataset showed a positive correlation between the amount of phosphorylated Akt-Ser473 and the expression of MAPT RNA encoding Tau, underlining the relevance of our findings in glioblastoma disease. We suggest a role for Tau in glioblastoma by controlling 3D cell organization and functions via the PI3K/AKT signaling axis

Peptide screen identifies a new NADPH oxidase inhibitor: impact on cell migration and invasion

International audienceno abstrac