Publications by authors named "Stephane Flament"

Background: The metabolism of cancer cells generally differs from that of normal cells. Indeed, most cancer cells have a high rate of glycolysis, even at normal oxygen concentrations. These metabolic properties can potentially be exploited for therapeutic intervention.

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We present the design, fabrication, and characterization of an implantable neural interface based on anisotropic magnetoresistive (AMR) magnetic-field sensors that combine reduced size and high performance at body temperature. The sensors are based on LaSrMnO (LSMO) as a ferromagnetic material, whose epitaxial growth has been suitably engineered to get uniaxial anisotropy and large AMR output together with low noise even at low frequencies. The performance of LSMO sensors of different film thickness and at different temperatures close to 37 °C has to be explored to find an optimum sensitivity of ∼400%/T (with typical detectivity values of 2 nT·Hz at a frequency of 1 Hz and 0.

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Breast cancer is one of the leading causes of cancer-related death among females worldwide. A major challenge is to develop innovative therapy in order to treat breast cancer subtypes resistant to current treatment. In the present study, we examined the effects of two Troglitazone derivatives Δ2-TGZ and AB186.

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Breast cancer is a major medical threat which cannot be sufficiently addressed by current therapies because of spontaneous or acquired treatment resistance. Besides, triple-negative breast cancer (TNBC) tumors do not respond to targeted therapies, thus new therapeutic strategies are needed. In this context, we designed and prepared new desulfured troglitazone (TGZ)-derived molecules and evaluated them in vitro for their anti-proliferative activity, with a special focus on triple-negative breast cancer cell lines.

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Because of the complex biological networks, many pathologic disorders fail to be treated with a molecule directed towards a single target. Thus, combination therapies are often necessary, but they have many drawbacks. An alternative consists in building molecules intended to interact with multiple targets, called designed multiple ligands.

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Purpose: Cancer cells often elicit a higher glycolytic rate than normal cells, supporting the development of glycolysis inhibitors as therapeutic agents. 2-Deoxyglucose (2-DG) is used in this context due to its ability to compete with glucose. However, many studies do not take into account that 2-DG inhibits not only glycolysis but also N-glycosylation.

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15-Deoxy-∆12,14-prostaglandin J2 (15d‑PGJ2) is a natural agonist of peroxisome proliferator-activated receptor γ (PPARγ) that displays anticancer activity. Various studies have indicated that the effects of 15d‑PGJ2 are due to both PPARγ-dependent and -independent mechanisms. In the present study, we examined the effects of a biotinylated form of 15d‑PGJ2 (b‑15d‑PGJ2) on hormone-dependent MCF‑7 and triple‑negative MDA‑MB‑231 breast cancer cell lines.

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Purpose: 40% of triple-negative breast cancer (TNBC) do not express claudin-1, a major constituent of tight junction. Patients with these "claudin-1-low" tumors present a higher relapse incidence. A major challenge in oncology is the development of innovative therapies for such poor prognosis tumors.

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We have previously shown that Δ2-Troglitazone (Δ2-TGZ) displayed anticancer effects on breast cancer cell lines grown in low serum conditions (1% fetal calf serum (FCS)). The present study was performed in order to characterize the effects of Δ2-TGZ in high serum containing medium and to determine if starvation could influence the response of breast cancer cells to this compound, keeping in mind the potential interest for breast cancer therapy. We observed that in high serum conditions (10% FCS), a 48 h treatment with Δ2-TGZ induced a decrease in cell numbers in MDA-MB-231 and MCF-7 breast cancer cell lines.

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Amphibians have been widely used to study developmental biology due to the fact that embryo development takes place independently of the maternal organism and that observations and experimental approaches are easy. Some amphibians like Xenopus became model organisms in this field. In the first part of this article, the differentiation of the gonads in amphibians and the mechanisms governing this process are reviewed.

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The existence of unresponsive tumors and the appearance of resistant tumors during the course of treatments both justify that we increase urgently the panel of pharmacological molecules able to fight cancer. An interesting strategy is drug reprofiling (also known as drug repositioning, drug repurposing or drug retasking) that consists of identifying and developing new uses for existing drugs. This review illustrates drug reprofiling with troglitazone (TGZ), a synthetic PPARγ agonist initially used for the treatment of type II diabetes.

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Background: Estrogen receptor alpha36 (ERalpha36), a variant of estrogen receptor alpha (ER) is expressed in about half of breast tumors, independently of the [ER+]/[ER-] status. In vitro, ERalpha36 triggers mitogenic non-genomic signaling and migration ability in response to 17beta-estradiol and tamoxifen. In vivo, highly ERalpha36 expressing tumors are of poor outcome especially as [ER+] tumors are submitted to tamoxifen treatment which, in turn, enhances ERalpha36 expression.

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The use of energy restriction mimetic agents (ERMAs) to selectively target cancer cells addicted to glycolysis could be a promising therapeutic approach. Thiazolidinediones (TZDs) are synthetic agonists of the nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ that were developed to treat type II diabetes. These compounds also display anticancer effects which appear mainly to be independent of their PPARγ agonist activity but the molecular mechanisms involved in the anticancer action are not yet well understood.

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Δ2-Troglitazone derivatives were shown to exhibit anti-proliferative activity in a PPARγ-independent manner. We prepared various compounds in order to increase their potency and decrease their toxicity towards non-malignant primary cultured hepatocytes. Many compounds induced viabilities less than 20% at 10 μM on various cancer cell lines.

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Our aim was to better understand peroxisome proliferator-activated receptor gamma (PPARγ)-independent pathways involved in anti-cancer effects of thiazolidinediones (TZDs). We focused on Δ2-troglitazone (Δ2-TGZ), a PPARγ inactive TZD that affects breast cancer cell viability. Appearance of TUNEL positive cells, changes in mitochondrial membrane potential, cleavage of poly(ADP-ribose) polymerase (PARP)-1 and caspase-7 revealed that apoptosis occurred in both hormone-dependent MCF7 and hormone-independent MDA-MB-231 breast cancer cells after 24 and 48 h of treatment.

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Müllerian inhibiting substance (MIS, also known as anti-Müllerian hormone), is a key factor of male sex differentiation in vertebrates. In amniotes, it is responsible for Müllerian duct regression in male embryos. In fish, despite the absence of Müllerian ducts, MIS is produced and controls germ cell proliferation during gonad differentiation.

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Long chain alkylphenols are man-made compounds still present in industrial and agricultural processes. Their main use is domestic and they are widespread in household products, cleansers and cosmetics, leading to a global environmental and human contamination. These molecules are known to exert estrogen-like activities through binding to classical estrogen receptors.

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Breast cancer is the most prevalent cancer in women. The development of resistances to therapeutic agents and the absence of targeted therapy for triple negative breast cancer motivate the search for alternative treatments. With this aim in mind, we synthesised new derivatives of troglitazone, a compound which was formerly used as an anti-diabetic agent and which exhibits anti-proliferative activity on various cancer cell lines.

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Seminoma, originated from carcinoma in situ cells (CIS), is one of the main causes of cancer in young men. Postpubertal development of these testicular germ cell tumors suggests a hormone-sensitive way of CIS cell proliferation induction. Using the unique seminoma TCam-2 cell line, we demonstrate that both estradiol and testosterone can stimulate TCam-2 cell proliferation in the absence of the estradiol receptor ERα.

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The SOX family of transcription factors is thought to regulate gene expression in a wide variety of developmental processes. Namely, SOX9 expression is conserved in vertebrate sex determination or differentiation. Nevertheless, information about caudate amphibians is lacking.

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Our aim was to get new information about the Peroxisome Proliferator Activated Receptor gamma (PPARγ)-independent pathway involved in the antiproliferative action of PPARγ ligands in breast cancer cells. We investigated the effects of Troglitazone (TGZ), Ciglitazone (CGZ), Rosiglitazone (RGZ) and, 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ(2)) on the hormone-dependent breast cancer cell line MCF7. The early transcription factor EGR1 (Early Growth Response gene 1) mRNA and protein levels peaked after 3h of incubation with 25μM TGZ, CGZ or 15d-PGJ(2) and then gradually decreased.

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Numerous recent studies indicate that most anticancer effects of PPARγ agonists like thiazolidinediones are the result of PPARγ-independent pathways. These conclusions were obtained by several approaches including the use of thiazolidinedione derivatives like Δ2-Troglitazone (Δ2-TGZ) that does not activate PPARγ. Since biotinylation has been proposed as a mechanism able to increase the specificity of drug delivery to cancer cells which could express a high level of vitamin receptor, a biotinylated derivative of Δ2-TGZ (bΔ2-TGZ) has been synthetized.

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Pleurodeles waltl is a urodele amphibian displaying a ZZ/ZW genetic mode of sex determination. Gonad differentiation can later be modulated by hormone treatment. To investigate germ cell differentiation, we analyzed the expression of the meiosis marker PwDmc1 and show that germ cells enter meiosis in late larval life in females, and 2 months after metamorphosis in males.

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