scholarly journals Apoptotic Sphingolipid Ceramide in Cancer Therapy

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Wei-Ching Huang ◽  
Chia-Ling Chen ◽  
Yee-Shin Lin ◽  
Chiou-Feng Lin

Apoptosis, also called programmed cell death, is physiologically and pathologically involved in cellular homeostasis. Escape of apoptotic signaling is a critical strategy commonly used for cancer tumorigenesis. Ceramide, a derivative of sphingolipid breakdown products, acts as second messenger for multiple extracellular stimuli including growth factors, chemical agents, and environmental stresses, such as hypoxia, and heat stress as well as irradiation. Also, ceramide acts as tumor-suppressor lipid because a variety of stress stimuli cause apoptosis by increasing intracellular ceramide to initiate apoptotic signaling. Defects on ceramide generation and sphingolipid metabolism are developed for cancer cell survival and cancer therapy resistance. Alternatively, targeting ceramide metabolism to correct these defects might provide opportunities to overcome cancer therapy resistance.

Cancers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 109 ◽  
Author(s):  
Maria Mrakovcic ◽  
Leopold F. Fröhlich

Histone deacetylation inhibitors (HDACi) offer high potential for future cancer therapy as they can re-establish the expression of epigenetically silenced cell death programs. HDACi-induced autophagy offers the possibility to counteract the frequently present apoptosis-resistance as well as stress conditions of cancer cells. Opposed to the function of apoptosis and necrosis however, autophagy activated in cancer cells can engage in a tumor-suppressive or tumor-promoting manner depending on mostly unclarified factors. As a physiological adaption to apoptosis resistance in early phases of tumorigenesis, autophagy seems to resume a tumorsuppressive role that confines tumor necrosis and inflammation or even induces cell death in malignant cells. During later stages of tumor development, chemotherapeutic drug-induced autophagy seems to be reprogrammed by the cancer cell to prevent its elimination and support tumor progression. Consistently, HDACi-mediated activation of autophagy seems to exert a protective function that prevents the induction of apoptotic or necrotic cell death in cancer cells. Thus, resistance to HDACi-induced cell death is often encountered in various types of cancer as well. The current review highlights the different mechanisms of HDACi-elicited autophagy and corresponding possible molecular determinants of therapeutic resistance in cancer.


2002 ◽  
Vol 277 (51) ◽  
pp. 49870-49876 ◽  
Author(s):  
Raquel Parı́s ◽  
Albert Morales ◽  
Olga Coll ◽  
Alberto Sánchez-Reyes ◽  
Carmen Garcı́a-Ruiz ◽  
...  

Ganglioside GD3 (GD3) has emerged as a modulator of cell death pathways due to its ability to interact with mitochondria and disable survival pathways. Because NF-κB activation contributes to cancer therapy resistance, this study was undertaken to test whether GD3 modulates the response of human hepatoblastoma HepG2 cells to radio- and chemotherapy. NF-κB was activated in HepG2 cells shortly after therapeutic doses of ionizing radiation or daunorubicin treatment that translated into up-regulation of κB-dependent genes. These effects were accompanied by minimal killing of HepG2 cells by either ionizing radiation or daunorubicin. However, GD3 pretreatment blocked the nuclear translocation of active κB members, without effect on Akt phosphorylation, induced by either treatment. The suppression of κB-dependent gene induction by GD3 was accompanied by enhanced apoptotic cell death caused by these therapies. Furthermore, the combination of GD3 plus ionizing radiation stimulated the formation of reactive species followed by the mitochondrial release of cytochromecand Smac/Diablo and caspase 3 activation. Pretreatment with cyclosporin A before radiotherapy protected HepG2 cells from the therapeutic combination of GD3 plus ionizing radiation. These findings underscore a key role of mitochondria in the response of tumor cells to cancer therapy and highlight the potential relevance of GD3 to overcome resistance to cancer therapy by combining its dual action as a mitochondria-interacting and NF-κB-inactivating agent.


2021 ◽  
Vol 478 (19) ◽  
pp. 3621-3642
Author(s):  
Botheina Ghandour ◽  
Ghassan Dbaibo ◽  
Nadine Darwiche

Sphingolipid-mediated regulation in cancer development and treatment is largely ceramide-centered with the complex sphingolipid metabolic pathways unfolding as attractive targets for anticancer drug discovery. The dynamic interconversion of sphingolipids is tightly controlled at the level of enzymes and cellular compartments in response to endogenous or exogenous stimuli, such as anticancer drugs, including retinoids. Over the past two decades, evidence emerged that retinoids owe part of their potency in cancer therapy to modulation of sphingolipid metabolism and ceramide generation. Ceramide has been proposed as a ‘tumor-suppressor lipid' that orchestrates cell growth, cell cycle arrest, cell death, senescence, autophagy, and metastasis. There is accumulating evidence that cancer development is promoted by the dysregulation of tumor-promoting sphingolipids whereas cancer treatments can kill tumor cells by inducing the accumulation of endogenous ceramide levels. Resistance to cancer therapy may develop due to a disrupted equilibrium between the opposing roles of tumor-suppressor and tumor-promoter sphingolipids. Despite the undulating effect and complexity of sphingolipid pathways, there are emerging opportunities for a plethora of enzyme-targeted therapeutic interventions that overcome resistance resulting from perturbed sphingolipid pathways. Here, we have revisited the interconnectivity of sphingolipid metabolism and the instrumental role of ceramide-biosynthetic and degradative enzymes, including bioactive sphingolipid products, how they closely relate to cancer treatment and pathogenesis, and the interplay with retinoid signaling in cancer. We focused on retinoid targeting, alone or in combination, of sphingolipid metabolism nodes in cancer to enhance ceramide-based therapeutics. Retinoid and ceramide-based cancer therapy using novel strategies such as combination treatments, synthetic retinoids, ceramide modulators, and delivery formulations hold promise in the battle against cancer


2018 ◽  
Vol 25 (36) ◽  
pp. 4758-4784 ◽  
Author(s):  
Amy L. Wilson ◽  
Magdalena Plebanski ◽  
Andrew N. Stephens

Cancer is one of the leading causes of death worldwide, and current research has focused on the discovery of novel approaches to effectively treat this disease. Recently, a considerable number of clinical trials have demonstrated the success of immunomodulatory therapies for the treatment of cancer. Monoclonal antibodies can target components of the immune system to either i) agonise co-stimulatory molecules, such as CD137, OX40 and CD40; or ii) inhibit immune checkpoints, such as cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death-1 (PD-1) and its corresponding ligand PD-L1. Although tumour regression is the outcome for some patients following immunotherapy, many patients still do not respond. Furthermore, chemotherapy has been the standard of care for most cancers, but the immunomodulatory capacity of these drugs has only recently been uncovered. The ability of chemotherapy to modulate the immune system through a variety of mechanisms, including immunogenic cell death (ICD), increased antigen presentation and depletion of regulatory immune cells, highlights the potential for synergism between conventional chemotherapy and novel immunotherapy. In addition, recent pre-clinical trials indicate dipeptidyl peptidase (DPP) enzyme inhibition, an enzyme that can regulate immune cell trafficking to the tumour microenvironment, as a novel cancer therapy. The present review focuses on the current immunological approaches for the treatment of cancer, and summarizes clinical trials in the field of immunotherapy as a single treatment and in combination with chemotherapy.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2168
Author(s):  
Balawant Kumar ◽  
Rizwan Ahmad ◽  
Swagat Sharma ◽  
Saiprasad Gowrikumar ◽  
Mark Primeaux ◽  
...  

Background: Despite recent advances in therapies, resistance to chemotherapy remains a critical problem in the clinical management of colorectal cancer (CRC). Cancer stem cells (CSCs) play a central role in therapy resistance. Thus, elimination of CSCs is crucial for effective CRC therapy; however, such strategies are limited. Autophagy promotes resistance to cancer therapy; however, whether autophagy protects CSCs to promote resistance to CRC-therapy is not well understood. Moreover, specific and potent autophagy inhibitors are warranted as clinical trials with hydroxychloroquine have not been successful. Methods: Colon cancer cells and tumoroids were used. Fluorescent reporter-based analysis of autophagy flux, spheroid and side population (SP) culture, and qPCR were done. We synthesized 36-077, a potent inhibitor of PIK3C3/VPS34 kinase, to inhibit autophagy. Combination treatments were done using 5-fluorouracil (5-FU) and 36-077. Results: The 5-FU treatment induced autophagy only in a subset of the treated colon cancer. These autophagy-enriched cells also showed increased expression of CSC markers. Co-treatment with 36-077 significantly improved efficacy of the 5-FU treatment. Mechanistic studies revealed that combination therapy inhibited GSK-3β/Wnt/β-catenin signaling to inhibit CSC population. Conclusion: Autophagy promotes resistance to CRC-therapy by specifically promoting GSK-3β/Wnt/β-catenin signaling to promote CSC survival, and 36-077, a PIK3C3/VPS34 inhibitor, helps promote efficacy of CRC therapy.


2021 ◽  
Author(s):  
Wooram Park ◽  
Seok-Jo Kim ◽  
Paul Cheresh ◽  
Jeanho Yun ◽  
Byeongdu Lee ◽  
...  

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein,...


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