Natural modulators of the hallmarks of immunogenic cell death

Radogna, Flavia,Dicato, Mario,Diederich, Marc Pergamon Press 2019 Biochemical pharmacology Vol.162 No.-

<P><B>Abstract</B></P> <P>Natural compounds act as immunoadjuvants as their therapeutic effects trigger cancer stress response and release of damage-associated molecular patterns (DAMPs). These reactions occur through an increase in the immunogenicity of cancer cells that undergo stress followed by immunogenic cell death (ICD). These processes result in a chemotherapeutic response with a potent immune-mediating reaction. Natural compounds that induce ICD may function as an interesting approach in converting cancer into its own vaccine. However, multiple parameters determine whether a compound can act as an ICD inducer, including the nature of the inducer, the <I>premortem</I> stress pathways, the cell death pathways, the intrinsic antigenicity of the cell, and the potency and availability of an immune cell response. Thus, the identification of hallmarks of ICD is important in determining the prognostic biomarkers for new therapeutic approaches and combination treatments.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Stress-induced cellular responses in immunogenic cell death: Implications for cancer immunotherapy

Radogna, Flavia,Diederich, Marc Elsevier 2018 Biochemical pharmacology Vol.153 No.-

<P><B>Abstract</B></P> <P>Cancer is evading the host’s defense mechanisms leading to avoidance of immune destruction. During tumor progression, immune-evading cancer cells arise due to selective pressure from the hypoxic and nutrient-deprived microenvironment. Thus, therapies aiming at re-establishing immune destruction of pathological cells constitute innovating anti-cancer strategies. Accumulating evidence suggests that selected conventional chemotherapeutic drugs increase the immunogenicity of stressed and dying cancer cells by triggering a form of cell death called immunogenic cell death (ICD), which is characterized by the release of danger-associated molecular patterns (DAMPs). In this review, we summarize the effects of ICD inducers on DAMP signaling leading to adjuvanticity and antigenicity. We will discuss the associated stress response pathways that cause the release of DAMPs leading to improved immune recognition and their relevance in cancer immunotherapy. Our aim is to highlight the contribution of adaptive immunity to the long-term clinical benefits of anticancer treatments and the properties of immune memory that can protect cancer patients against relapse.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Cell type-dependent ROS and mitophagy response leads to apoptosis or necroptosis in neuroblastoma

Radogna, F,Cerella, C,Gaigneaux, A,Christov, C,Dicato, M,Diederich, M Macmillan Publishers Limited 2016 Oncogene Vol.35 No.29

<P>A limiting factor in the therapeutic outcome of children with high-risk neuroblastoma is the intrinsic and acquired resistance to common chemotherapeutic treatments. Here we investigated the molecular mechanisms by which the hemisynthetic cardiac glycoside UNBS1450 overcomes this limitation and induces differential cell death modalities in both neuroblastic and stromal neuroblastoma through stimulation of a cell-type-specific autophagic response eventually leading to apoptosis or necroptosis. In neuroblastic SH-SY5Y cells, we observed a time-dependent production of reactive oxygen species that affects lysosomal integrity inducing lysosome-associated membrane protein 2 degradation and cathepsin B and L activation. Subsequent mitochondrial membrane depolarization and accumulation of mitochondria in phagophores occurred after 8h of UNBS1450 treatment. Results were confirmed by mitochondrial mass analysis, electron microscopy and co-localization of mitochondria with GFP-LC3, suggesting the impaired clearance of damaged mitochondria. Thus, a stress-induced defective autophagic flux and the subsequent lack of clearance of damaged mitochondria sensitized SH-SY5Y cells to UNBS1450-induced apoptosis. Inhibition of autophagy with small inhibitory RNAs against ATG5, ATG7 and Beclin-1 protected SH-SY5Y cells against the cytotoxic effect of UNBS1450 by inhibiting apoptosis. In contrast, autophagy progression towards the catabolic state was observed in stromal SK-N-AS cells: here reactive oxygen species (ROS) generation remained undetectable preserving intact lysosomes and engulfing damaged mitochondria after UNBS1450 treatment. Moreover, autophagy inhibition determined sensitization of SK-N-AS to apoptosis. We identified efficient mitophagy as the key mechanism leading to failure of activation of the apoptotic pathway that increased resistance of SK-N-AS to UNBS1450, triggering rather necroptosis at higher doses. Altogether we characterize here the differential modulation of ROS and mitophagy as a main determinant of neuroblastoma resistance with potential relevance for personalized anticancer therapeutic approaches.</P>

Natural Compounds as Regulators of the Cancer Cell Metabolism

Cerella, Claudia,Radogna, Flavia,Dicato, Mario,Diederich, Marc Hindawi Publishing Corporation 2013 International journal of cell biology Vol.2013 No.-

<P>Even though altered metabolism is an “old” physiological mechanism, only recently its targeting became a therapeutically interesting strategy and by now it is considered an emerging hallmark of cancer. Nevertheless, a very poor number of compounds are under investigation as potential modulators of cell metabolism. Candidate agents should display selectivity of action towards cancer cells without side effects. This ideal favorable profile would perfectly overlap the requisites of new anticancer therapies and chemopreventive strategies as well. Nature represents a still largely unexplored source of bioactive molecules with a therapeutic potential. Many of these compounds have already been characterized for their multiple anticancer activities. Many of them are absorbed with the diet and therefore possess a known profile in terms of tolerability and bioavailability compared to newly synthetized chemical compounds. The discovery of important cross-talks between mediators of the most therapeutically targeted aberrancies in cancer (i.e., cell proliferation, survival, and migration) and the metabolic machinery allows to predict the possibility that many anticancer activities ascribed to a number of natural compounds may be due, in part, to their ability of modulating metabolic pathways. In this review, we attempt an overview of what is currently known about the potential of natural compounds as modulators of cancer cell metabolism.</P>

From nature to bedside: Pro-survival and cell death mechanisms as therapeutic targets in cancer treatment

Cerella, C.,Teiten, M.H.,Radogna, F.,Dicato, M.,Diederich, M. Pergamon Press ; Elsevier Science Ltd 2014 BIOTECHNOLOGY ADVANCES Vol.32 No.6

Cell death is an important physiological regulator during development, tissue homeostasis and stress response but it is also a protective tumor suppressive mechanism. Tumor cells almost universally acquire the ability to evade cell death pathways that in normal cells act as a protective mechanism to remove damaged cells. As a result, a population of death-resistant cells with accumulating genetic and epigenetic abnormalities contributes to malignant transformation. Any alteration of the homeostatic balance between survival and death is therefore a critical factor in carcinogenesis. Several forms of cell death exist and cross talk among them is emerging; however, we still miss many molecular details. It becomes essential to revisit the role of each type of cell death to understand interconnections existing between different cell death pathways as well as the network of their mediators to eventually develop new effective strategies to kill cancer cells. More specifically, new therapies based on compounds selectively triggering apoptosis, necrosis or autophagy recently became both appealing and challenging. Despite the rather clear classification of the different cell death modalities according to morphological criteria and the attempt to describe them with distinct signaling pathways, the reality reveals a complex interplay between apoptosis, regulated necrosis and autophagy involving a heterogeneous mix of molecular mediators. Nature, presenting an almost endless plenitude of bioactive scaffolds, can efficiently contribute compounds that allow deciphering the intricate pathways of cell death pathways and thus eventually contribute to selectively target cancer-type specific pathways in an attempt to personalize cancer patient treatment depending on cancer death pathway specificities. The aim of this review is to provide first an overview of molecular cell death specificities and to highlight how compounds of natural origins, with or without hemisynthetic modifications, target unique thanatotic molecular constellations.

Tubulin-binding anticancer polysulfides induce cell death via mitotic arrest and autophagic interference in colorectal cancer

Yagdi Efe, Esma,Mazumder, Aloran,Lee, Jin-Young,Gaigneaux, Anthoula,Radogna, Flavia,Nasim, Muhammad Jawad,Christov, Christo,Jacob, Claus,Kim, Kyu-Won,Dicato, Mario,Chaimbault, Patrick,Cerella, Claudia Elsevier 2017 Cancer letters Vol.410 No.-

<P><B>Abstract</B></P> <P>Polysulfanes show chemopreventive effects against gastrointestinal tumors. We identified diallyl tetrasulfide and its derivative, dibenzyl tetrasulfide (DBTTS), to be mitotic inhibitors and apoptosis inducers. Here, we translate their application in colorectal cancer (CRC). MALDI-TOF-MS analysis identified both compounds as reversible tubulin binders, validated by <I>in cellulo</I> α-tubulin degradation. BRAF(V600E)-mutated HT-29 cells were resistant to DBTTS, as evidenced by mitotic arrest for 48 h prior to apoptosis induction compared to KRAS(G12V)-mutated SW480/620 cells, which committed to death earlier. The prolonged mitotic block correlated with autophagy impairment and p62 protein accumulation in HT-29 but not in SW480/620 cells, whereas siRNA-mediated p62 inhibition sensitized HT-29 cells to death. <I>In silico</I> analysis with 484 colorectal cancer patients associated higher p62 expression and reduced autophagic flux with greater overall survival. Accordingly, we hypothesized that DBTTS targets CRC survival/death through autophagy interference in cell types with differential autophagic capacities. We confirmed the therapeutic potential of DBTTS by the inhibition of spheroid and colony formation capacities in CRC cells, as well as in HT-29 zebrafish xenografts <I>in vivo</I>.</P>

Bcl-2 protein family expression pattern determines synergistic pro-apoptotic effects of BH3 mimetics with hemisynthetic cardiac glycoside UNBS1450 in acute myeloid leukemia

Cerella, C,Gaigneaux, A,Mazumder, A,Lee, J-Y,Saland, E,Radogna, F,Farge, T,Vergez, F,Ré,cher, C,Sarry, J-E,Kim, K-W,Shin, H Y,Dicato, M,Diederich, M Nature Publishing Group 2017 Leukemia Vol.31 No.3