Budget-Friendly Generation, Biochemical Analyses, and Lentiviral Transduction of Patient-Derived Colon Organoids.

For the past decade, three-dimensional (3D) culture models have been emerging as powerful tools in translational research to overcome the limitations of two-dimensional cell culture models. Thanks to their ability to recapitulate the phenotypic and molecular heterogeneity found in numerous organs, organoids have been used to model a broad range of tumors, such as colorectal cancer. Several approaches to generate organoids exist, with protocols using either pluripotent stem cells, embryonic stem cells, or organ-restricted adult stem cells found in primary tissues, such as surgical resections as starting material.

Indacaterol inhibits collective cell migration and IGDQ-mediated single cell migration in metastatic breast cancer MDA-MB-231 cells.

Metastasis is the main cause of deaths related to breast cancer. This is particular the case for triple negative breast cancer. No targeted therapies are reported as efficient until now.

The global downregulation of protein synthesis observed during hepatogenic maturation is associated with a decrease in TOP mRNA translation.

Translational regulation is of paramount importance for proteome remodeling during stem cell differentiation at both the global and the transcript-specific levels. In this study, we characterized translational remodeling during hepatogenic differentiation of induced pluripotent stem cells (iPSCs) by polysome profiling. We demonstrate that protein synthesis increases during exit from pluripotency and is then globally repressed during later steps of hepatogenic maturation.

Senescence Induced by UVB in Keratinocytes Impairs Amino Acids Balance.

Skin is one of the most exposed organs to external stress. Namely, UV rays are the most harmful stress that could induce important damage leading to skin aging and cancers. At the cellular level, senescence is observed in several skin cell types and contributes to skin aging.

IGDQ motogenic peptide gradient induces directional cell migration through integrin (αv)β3 activation in MDA-MB-231 metastatic breast cancer cells.

In the context of breast cancer metastasis study, we have shown in an in vitro model of cell migration that IGDQ-exposing (IsoLeu-Gly-Asp-Glutamine type I Fibronectin motif) monolayers (SAMs) on gold sustain the adhesion of breast cancer MDA-MB-231 cells by triggering Focal Adhesion Kinase and integrin activation. Such tunable scaffolds are used to mimic the tumor extracellular environment, inducing and controlling cell migration. The observed migratory behavior induced by the IGDQ-bearing peptide gradient along the surface allows to separate cell subpopulations with a "stationary" or "migratory" phenotype.

The HCV Envelope Glycoprotein Down-Modulates NF-κB Signalling and Associates With Stimulation of the Host Endoplasmic Reticulum Stress Pathway.

Following acute HCV infection, the virus establishes a chronic disease in the majority of patients whilst few individuals clear the infection spontaneously. The precise mechanisms that determine chronic HCV infection or spontaneous clearance are not completely understood but are proposed to be driven by host and viral genetic factors as well as HCV encoded immunomodulatory proteins. Using the HIV-1 LTR as a tool to measure NF-κB activity, we identified that the HCV E1E2 glycoproteins and more so the E2 protein down-modulates HIV-1 LTR activation in 293T, TZM-bl and the more physiologically relevant Huh7 liver derived cell line.

MPV17 does not control cancer cell proliferation.

MPV17 is described as a mitochondrial inner membrane channel. Although its function remains elusive, mutations in the MPV17 gene result in hepato-cerebral mitochondrial DNA depletion syndrome in humans. In this study, we show that MPV17 silencing does not induce depletion in mitochondrial DNA content in cancer cells.

Hybrid Alginate@TiO Porous Microcapsules as a Reservoir of Animal Cells for Cell Therapy.

The number of patients suffering from diseases linked with hormone deficiency (e.g., type 1 diabetes mellitus) has significantly increased in recent years.

Proton irradiation orchestrates macrophage reprogramming through NFκB signaling.

Tumor-associated macrophages (TAMs) represent potential targets for anticancer treatments as these cells play critical roles in tumor progression and frequently antagonize the response to treatments. TAMs are usually associated to an M2-like phenotype, characterized by anti-inflammatory and protumoral properties. This phenotype contrasts with the M1-like macrophages, which exhibits proinflammatory, phagocytic, and antitumoral functions.

Unraveling the interplay between senescent dermal fibroblasts and cutaneous squamous cell carcinoma cell lines at different stages of tumorigenesis.

Cutaneous Squamous Cell Carcinoma (cSCC) is the second most common type of non-melanoma skin cancer in white-skinned populations. cSCC is associated with sun exposure and aging, which is concomitant with an accumulation of senescent cells in the skin. The involvement of senescent cells in carcinogenesis has been highlighted in several cancer types and an interaction between cSCC cells and senescent cells is proposed, but still little explored.

The Transcription Factor 7-Like 2-Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Axis Connects Mitochondrial Biogenesis and Metabolic Shift with Stem Cell Commitment to Hepatic Differentiation.

Increasing evidence supports that modifications in the mitochondrial content, oxidative phosphorylation (OXPHOS) activity, and cell metabolism influence the fate of stem cells. However, the regulators involved in the crosstalk between mitochondria and stem cell fate remains poorly characterized. Here, we identified a transcriptional regulatory axis, composed of transcription factor 7-like 2 (TCF7L2) (a downstream effector of the Wnt/β-catenin pathway, repressed during differentiation) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) (the master regulator of mitochondrial biogenesis, induced during differentiation), coupling the loss of pluripotency and early commitment to differentiation, to the initiation of mitochondrial biogenesis and metabolic shift toward OXPHOS.

Chromatin remodeling regulates catalase expression during cancer cells adaptation to chronic oxidative stress.

Regulation of ROS metabolism plays a major role in cellular adaptation to oxidative stress in cancer cells, but the molecular mechanism that regulates catalase, a key antioxidant enzyme responsible for conversion of hydrogen peroxide to water and oxygen, remains to be elucidated. Therefore, we investigated the transcriptional regulatory mechanism controlling catalase expression in three human mammary cell lines: the normal mammary epithelial 250MK primary cells, the breast adenocarcinoma MCF-7 cells and an experimental model of MCF-7 cells resistant against oxidative stress resulting from chronic exposure to HO (Resox), in which catalase was overexpressed. Here we identify a novel promoter region responsible for the regulation of catalase expression at -1518/-1226 locus and the key molecules that interact with this promoter and affect catalase transcription.

Effects of a Sublethal and Transient Stress of the Endoplasmic Reticulum on the Mitochondrial Population.

Endoplasmic reticulum (ER) and mitochondria are not discrete intracellular organelles but establish close physical and functional interactions involved in several biological processes including mitochondrial bioenergetics, calcium homeostasis, lipid synthesis, and the regulation of apoptotic cell death pathways. As many cell types might face a transient and sublethal ER stress during their lifetime, it is thus likely that the adaptive UPR response might affect the mitochondrial population. The aim of this work was to study the putative effects of a non-lethal and transient endoplasmic reticulum stress on the mitochondrial population in HepG2 cells.

M1 and M2 macrophages derived from THP-1 cells differentially modulate the response of cancer cells to etoposide.

Background: Tumor associated macrophages (TAMs) are present in high density in solid tumors. TAMs share many characteristics with alternatively activated macrophages, also called M2. They have been shown to favor tumor development and a role in chemoresistance has also been suggested.

Taxol-induced unfolded protein response activation in breast cancer cells exposed to hypoxia: ATF4 activation regulates autophagy and inhibits apoptosis.

Understanding the mechanisms responsible for the resistance against chemotherapy-induced cell death is still of great interest since the number of patients with cancer increases and relapse is commonly observed. Indeed, the development of hypoxic regions as well as UPR (unfolded protein response) activation is known to promote cancer cell adaptive responses to the stressful tumor microenvironment and resistance against anticancer therapies. Therefore, the impact of UPR combined to hypoxia on autophagy and apoptosis activation during taxol exposure was investigated in MDA-MB-231 and T47D breast cancer cells.

Hypersensitivity of mtDNA-depleted cells to staurosporine-induced apoptosis: roles of Bcl-2 downregulation and cathepsin B.

We show that mitochondrial DNA (mtDNA)-depleted 143B cells are hypersensitive to staurosporine-induced cell death as evidenced by a more pronounced DNA fragmentation, a stronger activation of caspase-3, an enhanced poly(ADP-ribose) polymerase-1 (PARP-1) cleavage, and a more dramatic cytosolic release of cytochrome c. We also show that B-cell CLL/lymphoma-2 (Bcl-2), B-cell lymphoma extra large (Bcl-X(L)), and myeloid cell leukemia-1 (Mcl-1) are constitutively less abundant in mtDNA-depleted cells, that the inhibition of Bcl-2 and Bcl-X(L) can sensitize the parental cell line to staurosporine-induced apoptosis, and that overexpression of Bcl-2 or Bcl-X(L) can prevent the activation of caspase-3 in ρ(0)143B cells treated with staurosporine. Moreover, the inactivation of cathepsin B with CA074-Me significantly reduced cytochrome c release, caspase-3 activation, PARP-1 cleavage, and DNA fragmentation in mtDNA-depleted cells, whereas the pan-caspase inhibitor failed to completely prevent PARP-1 cleavage and DNA fragmentation in these cells, suggesting that caspase-independent mechanisms are responsible for cell death even if caspases are activated.

Gene expression silencing with 'specific' small interfering RNA goes beyond specificity - a study of key parameters to take into account in the onset of small interfering RNA off-target effects.

RNA-mediated gene silencing (RNA interference) is a powerful way to knock down gene expression and has revolutionized the fields of cellular and molecular biology. Indeed, the transfection of cultured cells with small interfering RNAs (siRNAs) is currently considered to be the best and easiest approach to loss-of-function experiments. However, several recent studies underscore the off-target and potential cytotoxic effects of siRNAs, which can lead to the silencing of unintended mRNAs.