Significance is reported as: * 0

Significance is reported as: * 0.05, ** 0.01, *** 0.001 compared to controls. Glucoevatromonoside abrogates tumor formation in a 3d culture environment and zebrafish xenografts We then confirmed the potential of GEV to impair the ability of A549 cells in and 3D tumor formation assays in the presence of increasing concentrations of the compound. cell death was caspase-independent, as investigated by a multiparametric approach, and culminates in severe morphological alterations in A549 cells, monitored by transmission electron microscopy, live cell imaging and flow cytometry. This non-canonical cell death was not preceded or accompanied by exacerbation of autophagy. In the presence of GEV, markers of autophagic flux (e.g. LC3I-II conversion) were impacted, even in presence of bafilomycin A1. Cell death induction remained unaffected by calpain, cathepsin, parthanatos, or necroptosis inhibitors. Interestingly, GEV triggered caspase-dependent apoptosis in U937 acute myeloid leukemia cells, witnessing cancer-type specific cell death induction. Differential cell cycle modulation by this CG led to a G2/M arrest, cyclin B1 and p53 downregulation in A549, but not in U937 cells. We further extended the anti-cancer potential of GEV to 3D cell culture using clonogenic and spheroid formation assays and validated our findings by zebrafish xenografts. Altogether, GEV shows an interesting anticancer profile with the ability to exert cytotoxic effects via induction of different cell death modalities. (Castro Braga et al., 1996). In this study, we initially focused on lung cancer as one of the most common form of cancer worldwide with a poor 5-year survival rate (25%), despite the recent implementation of targeted therapies, thus yet clearly needing new treatment avenues to be discovered. We investigated the effect of GEV on a panel of lung cancer cell lines and selected A549 (Schneider et al., 2018) as a cell type representing non-small cell lung adenocarcinoma, the most frequent histological form of lung cancer in both smokers and non-smokers. In order to provide a proof of concept of the activity of GEV, we generalized our findings on a Galanthamine panel of cancer cell models from different tissues, including examples of other solid and hematological forms. GEV exhibits a significant cytostatic and cytotoxic effect at Galanthamine nanomolar levels in adherent and non-adherent cancer cell types, without affecting healthy cell models. Our results demonstrate the capacity of GEV to activate caspase-independent cell death in the lung cancer model, validated by 2D and 3D cell culture, spheroid and colony formation assays as well as by zebrafish xenografts. Furthermore, here we extended our mechanistic studies to an example of hematological cancer by selecting U937 cells, which exhibit a similar susceptibility to GEV compared to A549 cells to Galanthamine be within a comparable concentration range for the induction of cell death modalities. Our results show in this instance the induction of a caspase-dependent apoptosis, indicating a cancer cell type-specific induction of different modalities of cell death induced by GEV. Materials and methods Cardenolides and chemicals The origin of all tested cardenolides is indicated in Supplementary Table 1. Compounds were dissolved in dimethyl sulfoxide (DMSO) (Merck, Darmstadt, Germany). Paclitaxel was from Sigma-Aldrich (St. Louis, USA). Etoposide, 3-aminobenzamide (3-ABA), cathepsin L inhibitor, and bafilomycin A1 were from Sigma-Aldrich (Bornem, Belgium). z-VAD-FMK (z-VAD), necrostatin (Nec)-1, and calpain inhibitor PD150606 were from Calbiochem (Leuven, Belgium). Cathepsin B inhibitor was from Cell Signaling Technology (Bioke, Leiden, The Netherlands). Mammalian Target of Rapamycin (mTOR) inhibitor PP242 (Torkinib) was from Sigma-Aldrich. Cells Human non-small cell lung cancer (NSCLC) A549 cells (ATCC, Manassas, USA) and normal fetal lung fibroblast cells (MRC-5, ECACC, Salisbury, UK) were grown in Dulbecco’s Modified Eagle’s Medium (DMEM; Gibco? Carlsbad, CA, USA) supplemented with 10% (v/v) fetal bovine serum (FBS; Gibco?). MRC-5 cells were complemented with 2 mM glutamine (Cultilab, Campinas, S?o Paulo, BR) and 1% non-essential amino acids (Gibco?). NSCLC cell lines H1573, H1975, H1437, and H1299 were from ATCC (LGC Standards, Molsheim, France). HT-29 (human colon adenocarcinoma), MADH3 SK-N-AS and SH-SY5Y (human neuroblastoma), K562 (chronic myelogenous leukemia), U937 (acute myeloid leukemia), Jurkat (T-cell leukemia), and Raji (Burkitt’s Lymphoma) cells were from DSMZ (Braunschweig, Germany); cells were cultured Galanthamine in RPMI medium (Lonza, Verviers, BE) supplemented with 10% (v/v) fetal calf serum (FCS) (Lonza) and 1% (v/v) antibiotic-antimycotic (penicillin, streptomycin, and amphotericin B) (BioWhittaker, Verviers, Belgium). Peripheral blood mononuclear cells (PBMCs) were purified using Ficoll-Hypaque (GE Healthcare, Roosendaal, The Netherlands). PBMCs were isolated by density gradient centrifugation from freshly collected buffy coats obtained from healthy adult human volunteers (Red Cross, Luxembourg, Luxembourg). All healthy volunteers gave informed written consent. After isolation, cells were washed twice.