scholarly journals Oncogenic signaling inhibits c-FLIPL expression and its non-apoptotic function during ECM-detachment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matyas Abel Tsegaye ◽  
Jianping He ◽  
Kyle McGeehan ◽  
Ireland M. Murphy ◽  
Mati Nemera ◽  
...  
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Protein C ◽  
Tumor Tissue ◽  
Oncogenic Signaling ◽  
Inhibitory Protein ◽  
Cell Death Pathways ◽  
Apoptotic Protein ◽  
Cellular Context ◽  
Context Dependent

AbstractInhibition of programmed cell death pathways is frequently observed in cancer cells where it functions to facilitate tumor progression. However, some proteins involved in the regulation of cell death function dichotomously to both promote and inhibit cell death depending on the cellular context. As such, understanding how cell death proteins are regulated in a context-dependent fashion in cancer cells is of utmost importance. We have uncovered evidence that cellular FLICE-like Inhibitory Protein (c-FLIP), a well-known anti-apoptotic protein, is often downregulated in tumor tissue when compared to adjacent normal tissue. These data argue that c-FLIP may have activity distinct from its canonical role in antagonizing cell death. Interestingly, we have discovered that detachment from extracellular matrix (ECM) serves as a signal to elevate c-FLIP transcription and that oncogenic signaling blocks ECM-detachment-induced c-FLIP elevation. In addition, our data reveal that downregulation of c-FLIP promotes luminal filling in mammary acini and that c-FLIP overexpression in cancer cells inhibits colony formation in cells exposed to ECM-detachment. Taken together, our study reveals an unexpected, non-apoptotic role for c-FLIP during ECM-detachment and raises the possibility that c-FLIP may have context-dependent roles during tumorigenesis.

scholarly journals Oncogenic signaling inhibits c-FLIP expression and promotes cancer cell survival during ECM-detachment

2021 ◽  
Author(s):  
Matyas Abel Tsegaye ◽  
Jianping He ◽  
Kyle McGeehan ◽  
Ireland M. Murphy ◽  
Mati Nemera ◽  
...  
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Protein C ◽  
Oncogenic Signaling ◽  
Inhibitory Protein ◽  
Cell Death Pathways ◽  
Apoptotic Protein ◽  
Cancer Cell Survival ◽  
Cellular Context ◽  
Context Dependent

AbstractInhibition of programmed cell death pathways is frequently observed in cancer cells where it functions to facilitate tumor progression. However, some proteins involved in the regulation of cell death function dichotomously to both promote and inhibit cell death depending on the cellular context. As such, understanding how cell death proteins are regulated in a context-dependent fashion in cancer cells is of utmost importance. We have uncovered evidence that cellular FLICE-like Inhibitory Protein (c-FLIP), a well-known anti-apoptotic protein, is often downregulated in tumor tissue when compared to adjacent normal tissue. These data argue that c-FLIP may have activity distinct from its canonical role in antagonizing cell death. Interestingly, we have discovered that detachment from extracellular matrix (ECM) serves as a signal to elevate c-FLIP transcription and that oncogenic signaling blocks ECM-detachment-induced c-FLIP elevation. In addition, our data reveal that downregulation of c-FLIP promotes the survival of ECM-detached cells and that c-FLIP overexpression in cancer cells restricts the viability of cancer cells grown in anchorage-independent conditions. Taken together, our study reveals an unexpected role for c-FLIP in constraining the viability of cancer cells during ECM-detachment and raises the idea that c-FLIP may have context-dependent pro- and anti-cell death roles during tumorigenesis.

scholarly journals The Novel ALG-2 Target Protein CDIP1 Promotes Cell Death by Interacting with ESCRT-I and VAPA/B

2021 ◽  
Vol 22 (3) ◽  
pp. 1175
Author(s):  
Ryuta Inukai ◽  
Kanako Mori ◽  
Keiko Kuwata ◽  
Chihiro Suzuki ◽  
Masatoshi Maki ◽  
...  
Keyword(s):  
Cell Death ◽  
Essential Gene ◽  
Susceptibility Gene ◽  
Target Protein ◽  
Hek293 Cells ◽  
Dependent Manner ◽  
Gene Encoding ◽  
Endosomal Sorting ◽  
Cell Death Pathways ◽  
Apoptotic Protein

Apoptosis-linked gene 2 (ALG-2, also known as PDCD6) is a member of the penta-EF-hand (PEF) family of Ca2+-binding proteins. The murine gene encoding ALG-2 was originally reported to be an essential gene for apoptosis. However, the role of ALG-2 in cell death pathways has remained elusive. In the present study, we found that cell death-inducing p53 target protein 1 (CDIP1), a pro-apoptotic protein, interacts with ALG-2 in a Ca2+-dependent manner. Co-immunoprecipitation analysis of GFP-fused CDIP1 (GFP-CDIP1) revealed that GFP-CDIP1 associates with tumor susceptibility gene 101 (TSG101), a known target of ALG-2 and a subunit of endosomal sorting complex required for transport-I (ESCRT-I). ESCRT-I is a heterotetrameric complex composed of TSG101, VPS28, VPS37 and MVB12/UBAP1. Of diverse ESCRT-I species originating from four VPS37 isoforms (A, B, C, and D), CDIP1 preferentially associates with ESCRT-I containing VPS37B or VPS37C in part through the adaptor function of ALG-2. Overexpression of GFP-CDIP1 in HEK293 cells caused caspase-3/7-mediated cell death. In addition, the cell death was enhanced by co-expression of ALG-2 and ESCRT-I, indicating that ALG-2 likely promotes CDIP1-induced cell death by promoting the association between CDIP1 and ESCRT-I. We also found that CDIP1 binds to vesicle-associated membrane protein-associated protein (VAP)A and VAPB through the two phenylalanines in an acidic tract (FFAT)-like motif in the C-terminal region of CDIP1, mutations of which resulted in reduction of CDIP1-induced cell death. Therefore, our findings suggest that different expression levels of ALG-2, ESCRT-I subunits, VAPA and VAPB may have an impact on sensitivity of anticancer drugs associated with CDIP1 expression.

scholarly journals Evaluation of cell death pathways initiated by antitumor drugs melatonin and valproic acid in bladder cancer cells

FEBS Open Bio ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 798-810 ◽  
Author(s):  
Siwei Liu ◽  
Bilin Liang ◽  
Huiting Jia ◽  
Yuhan Jiao ◽  
Zhongqiu Pang ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Bladder Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Antitumor Drugs ◽  
Cell Death Pathways ◽  
Bladder Cancer Cells

scholarly journals A Priori Activation of Apoptosis Pathways of Tumor (AAAPT) Technology: Development of Targeted Apoptosis Initiators for Cancer Treatment

2019 ◽  
Author(s):  
Raghu Pandurangi ◽  
Marco Tomasetti ◽  
Thillai Verapazham Sekar ◽  
Ramasamy Paulmurugan ◽  
Cynthia Ma ◽  
...  
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Technology Development ◽  
Tumor Regression ◽  
A Priori ◽  
Specific Cell ◽  
Cell Death Pathways ◽  
Survival Pathways ◽  
Apoptosis Pathways

AbstractCancer cells develop tactics to circumvent the interventions by desensitizing themselves to interventions. The principle routes of desensitization include a) activation of survival pathways (e.g. NF-kB, PARP) and b) downregulation of cell death pathways (e.g. CD95/CD95L). As a result, it requires high therapeutic dose to achieve tumor regression which, in turn damages normal cells through the collateral damaging effects. Methods are needed to sensitize the low and non-responsive resistant tumor cells including cancer stem cells (CSCs) in order to evoke a better response from the current treatments. Current treatments including chemotherapy can induce cell death only in bulk cancer cells sparing CSCs and cancer resistant cells (CRCs) which are shown to be responsible for high recurrence of disease and low patient survival. Here, we report several novel tumor targeted sensitizers derived from the natural Vitamin E analogue (AMP-001-003). The drug design is based on a novel concept “A priori activation of apoptosis pathways of tumor technology (AAAPT) which is designed to activate specific cell death pathways and inhibit survival pathways simultaneously. Our results indicate that AMP-001-003 sensitize various types of cancer cells including MDA-MB-231 (triple negative breast cancer), PC3 (prostate cancer) and A543 (ling cancer) cells resulting in reducing the IC-50 of doxorubicin in vitro. At higher dose, AMP-001 acts as an anti-tumor agent on its own. The synergy between AMP-001 and doxorubicin could pave a new pathway to use AMP-001 as a neoadjuvant to chemotherapy to achieve a better efficacy and reduced off-target toxicity by the current treatments.Summary StatementA Priori Activation of Apoptosis Pathways of Tumor often referred to as “AAAPT” is a novel targeted tumor sensitizing technology which synergizes with chemotherapy to enhance the treatment efficacy.

scholarly journals Silymarin and Cancer: A Dual Strategy in Both in Chemoprevention and Chemosensitivity

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2009 ◽  
Author(s):  
Dominique Delmas ◽  
Jianbo Xiao ◽  
Anne Vejux ◽  
Virginie Aires
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Current Knowledge ◽  
Organic Anion ◽  
Chemotherapeutic Agents ◽  
Normal Cells ◽  
Antiapoptotic Proteins ◽  
Cell Death Pathways ◽  
Anion Transporters ◽  
Atp Binding Cassettes

Silymarin extracted from milk thistle consisting of flavonolignan silybin has shown chemopreventive and chemosensitizing activity against various cancers. The present review summarizes the current knowledge on the potential targets of silymarin against various cancers. Silymarin may play on the system of xenobiotics, metabolizing enzymes (phase I and phase II) to protect normal cells against various toxic molecules or to protect against deleterious effects of chemotherapeutic agents on normal cells. Furthermore, silymarin and its main bioactive compounds inhibit organic anion transporters (OAT) and ATP-binding cassettes (ABC) transporters, thus contributing to counteracting potential chemoresistance. Silymarin and its derivatives play a double role, namely, limiting the progression of cancer cells through different phases of the cycle—thus forcing them to evolve towards a process of cell death—and accumulating cancer cells in a phase of the cell cycle—thus making it possible to target a greater number of tumor cells with a specific anticancer agent. Silymarin exerts a chemopreventive effect by inducing intrinsic and extrinsic pathways and reactivating cell death pathways by modulation of the ratio of proapoptotic/antiapoptotic proteins and synergizing with agonists of death domains receptors. In summary, we highlight how silymarin may act as a chemopreventive agent and a chemosensitizer through multiple pathways.

scholarly journals Iron and Cancer

2018 ◽  
Vol 38 (1) ◽  
pp. 97-125 ◽  
Author(s):  
Suzy V. Torti ◽  
David H. Manz ◽  
Bibbin T. Paul ◽  
Nicole Blanchette-Farra ◽  
Frank M. Torti
Keyword(s):  
Cell Death ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Cancer Biology ◽  
Experimental Studies ◽  
Epidemiological Studies ◽  
Excess Iron ◽  
Cell Death Pathways ◽  
Dependent Form ◽  
Active Research

This review explores the multifaceted role that iron has in cancer biology. Epidemiological studies have demonstrated an association between excess iron and increased cancer incidence and risk, while experimental studies have implicated iron in cancer initiation, tumor growth, and metastasis. The roles of iron in proliferation, metabolism, and metastasis underpin the association of iron with tumor growth and progression. Cancer cells exhibit an iron-seeking phenotype achieved through dysregulation of iron metabolic proteins. These changes are mediated, at least in part, by oncogenes and tumor suppressors. The dependence of cancer cells on iron has implications in a number of cell death pathways, including ferroptosis, an iron-dependent form of cell death. Uniquely, both iron excess and iron depletion can be utilized in anticancer therapies. Investigating the efficacy of these therapeutic approaches is an area of active research that promises substantial clinical impact.

Instructed-Assembly as Context-Dependent Nanoscale Signals for Death and Morphogenesis of Cells

2019 ◽  
Author(s):  
Huaimin Wang ◽  
Zhaoqianqi Feng ◽  
Bing Xu
Keyword(s):  
Cell Death ◽  
Enzyme Activity ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Drug Screening ◽  
Cell Behavior ◽  
Biological Functions ◽  
Cell Spheroids ◽  
Cellular Environment ◽  
Context Dependent

Context-dependent signaling, as a ubiquitous phenomenon in nature, is a dynamic molecular process at nano- and microscales, but how to mimic its essence using non-covalent synthesis in cellular environment has yet to be developed. Here we show a dynamic continuum of non-covalent filaments formed by instructed-assembly (iA) of a supramolecular phosphoglycopeptide (sPGP) as context-dependent signals for controlling death and morphogenesis of cells. Specifically, while enzymes (i.e., ectophosphatases) on cancer cells catalyze the formation of the filaments of the sPGP to result in cell death, damping the enzyme activity induces 3D cell spheroids. Similarly, relying on the ratio of stromal and cancer cells in a co-culture to modulate the expression of the ectophosphatase, the iA process enables cell spheroids. The spheroids act as a mimic of tumor microenvironment for drug screening. As the first demonstration of iA as multifunctional processes according to local enzyme activity for controlling cell behavior, this work illustrates context-dependent biological functions of non-covalent synthesis in cellular environment.

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