Lipoic acid decreases Mcl-1, Bcl-xL

International audienceOvarian carcinoma is the leading cause of death from gynecological cancer because there is risk of chemoresistance. As previously demonstrated in our laboratory, Alpha-lipoic acid (LA), a co-factor for metabolic enzymes, suppresses the tumor growth. In this study, we have researched the mechanisms that are responsible for the activity of LA. We have studied the mechanisms of LA in two ovarian cancer cell lines, a cisplatin sensitive one, IGROV1 and its resistant counterpart, IGROV1-R10. These cells have been exposed to lipoic acid at various concentrations. Cell proliferation, cell cycle repartition and nuclear staining with DAPI were recorded. Western blot analyses were performed to detect various proteins implied in apoptotic cell death pathways. To investigate the formation of ROS, the oxidation of CM-DCFH2-DA were also determined. LA suppressed growth proliferation and induced apoptosis in both ovarian cell lines. Moreover, LA provoked a down regulation of two anti-apoptotic proteins, Mcl-1 and Bcl-xL protein and a strong induction of the BH3-only protein Bim. Furthermore, LA induced ROS generation which could be involved in the CHOP induction which is known to activate the Bim translation. Our results reveal novel actions of LA which could explain the anti-tumoral effects of the LA. Therefore, LA seems to be a promising compound for ovarian cancer treatment

Impact of Hypoxia and Hadrontherapy on Radioresistant Chondrosarcoma Cancer Stem Cells

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Impact de l'hadronthérapie par ions carbone et protons sur les cellules souches cancéreuses de chondrosarcome en hypoxie

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Interest of the qPCR method calibrated with flow cytometry to quantify Aspergillus versicolor in mold-damaged homes and comparison with the cultural approach

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Impact de l'hadronthérapie par ions carbone et protons sur les cellules souches cancéreuses de chondrosarcome en hypoxie

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Impact of Hypoxia and Hadrontherapy on Radioresistant Chondrosarcoma Cancer Stem Cells

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Genotoxic effects of cadmium in human head and neck cell line SQ20B

International audienceAs cadmium may be involved in the etiology of head and neck cancers, we investigated in the present work, the cytotoxic and genotoxic effects of Cd on human larynx cells. SQ20B cells were exposed to 25 and 50 μM Cd for 48 and 72 h. Results showed a dose-dependent decrease in cell viability, especially after 48 h, associated with mitochondria alterations as showed by transmission electronic microscopy. Surprisingly, the flow cytometry shows that the cells treated with Cd have a normal proliferative cycle like the untreated cell especially in G1 or G2 phase of cell cycle. DNA damages were investigated by comet assay and immunofluorescence for gamma layer of the H2AX (g-H2AX) foci formation. Results show a strong induction of DNA double-strand breaks after Cd exposure. Overall, our results demonstrate the cytotoxicity and genotoxicity of Cd in human larynx cells and support the view that Cd could be an etiologic factor of head and neck cancers

Cytotoxicity and genotoxicity effects of arsenic trioxide on SQ20B human laryngeal carcinoma cells

International audienceThis study investigates the cytotoxicity and the genotoxicity induced by arsenic trioxide As2O3in human laryngeal SQ20B carcinoma cell line. SQ20B cells were exposed to graded concentrations of arsenic trioxide (2 and 5μM) for 48h. Comet assay and γ-H2AX foci formation were used for measuring DNA damages, flow cytometry was used to identify cell cycle alterations and apoptosis, while cell morphology was visualized using transmission electron microscopy. The results show a dose-dependent induction of DNA damages and double strand breaks, alterations in cell cycle and morphologic alterations of cells. These results prove that As2O3 is highly cytotoxic and genotoxic at the micromolar range ina human laryngeal carcinoma cell line

Flow cytometry for receptor analysis from ex-vivo brain tissue in adult rat

International audienceBACKGROUND:Flow cytometry allows single-cell analysis of peripheral biological samples and is useful in many fields of research and clinical applications, mainly in hematology, immunology, and oncology. In the neurosciences, the flow cytometry separation method was first applied to stem cell extraction from healthy or cerebral tumour tissue and was more recently tested in order to phenotype brain cells, hippocampal neurogenesis, and to detect prion proteins. However, it remains sparsely applied in quantifying membrane receptors in relation to synaptic plasticity.NEW METHOD:We aimed to optimize a flow cytometric procedure for receptor quantification in neurons and non-neurons. A neural dissociation process, myelin separation, fixation, and membrane permeability procedures were optimized to maximize cell survival and analysis in hippocampal tissue obtained from adult rodents. We then aimed to quantify membrane muscarinic acetylcholine receptors (mAChRs) in rats with and without bilateral vestibular loss (BVL).RESULTS:mAChR's were quantified for neuronal and non-neuronal cells in the hippocampus and striatum following BVL. At day 30 but not at day 7 following BVL, there was a significant increase (P ≤ 0.05) in the percentage of neurons expressing M2/4 mAChRs in both the hippocampus and the striatum.CONCLUSION:Here, we showed that flow cytometry appears to be a reliable method of membrane receptor quantification in ex-vivo brain tissue