1
|
Keyvani V, Riahi E, Yousefi M, Esmaeili SA, Shafabakhsh R, Moradi Hasan-Abad A, Mahjoubin-Tehran M, Hamblin MR, Mollazadeh S, Mirzaei H. Gynecologic Cancer, Cancer Stem Cells, and Possible Targeted Therapies. Front Pharmacol 2022; 13:823572. [PMID: 35250573 PMCID: PMC8888850 DOI: 10.3389/fphar.2022.823572] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Gynecologic cancer is one of the main causes of death in women. In this type of cancer, several molecules (oncogenes or tumor suppressor genes) contribute to the tumorigenic process, invasion, metastasis, and resistance to treatment. Based on recent evidence, the detection of molecular changes in these genes could have clinical importance for the early detection and evaluation of tumor grade, as well as the selection of targeted treatment. Researchers have recently focused on cancer stem cells (CSCs) in the treatment of gynecologic cancer because of their ability to induce progression and recurrence of malignancy. This has highlighted the importance of a better understanding of the molecular basis of CSCs. The purpose of this review is to focus on the molecular mechanism of gynecologic cancer and the role of CSCs to discover more specific therapeutic approaches to gynecologic cancer treatment.
Collapse
Affiliation(s)
- Vahideh Keyvani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Espanta Riahi
- Blood Borne Infections Research Center, Academic Center for Education, Culture and Research (ACECR), Mashhad, Iran; Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | - Meysam Yousefi
- Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Seyed-Alireza Esmaeili
- Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Immunology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Rana Shafabakhsh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Amin Moradi Hasan-Abad
- Autoimmune Diseases Research Center, Kashan University of Medical Sciences, Kashan, Iran
| | - Maryam Mahjoubin-Tehran
- Department of Medical Biotechnology and Nanotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Michael R. Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, South Africa
| | - Samaneh Mollazadeh
- Natural Products and Medicinal Plants Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
- *Correspondence: Samaneh Mollazadeh, ; Hamed Mirzaei, ,
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
- Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran
- *Correspondence: Samaneh Mollazadeh, ; Hamed Mirzaei, ,
| |
Collapse
|
2
|
Regulation of Cancer Metastasis by TRAIL/Death Receptor Signaling. Biomolecules 2021; 11:biom11040499. [PMID: 33810241 PMCID: PMC8065657 DOI: 10.3390/biom11040499] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/17/2021] [Accepted: 03/24/2021] [Indexed: 12/11/2022] Open
Abstract
Death ligands such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL; TNFSF10) and their corresponding death receptors (e.g., DR5) not only initiate apoptosis through activation of the extrinsic apoptotic pathway but also exert non-apoptotic biological functions such as regulation of inflammation and cancer metastasis. The involvement of the TRAIL/death receptor signaling pathway in the regulation of cancer invasion and metastasis is complex as both positive and negative roles have been reported. The underlying molecular mechanisms are even more complicated. This review will focus on discussing current knowledge in our understanding of the involvement of TRAIL/death receptor-mediated signaling in the regulation of cancer cell invasion and metastasis.
Collapse
|
3
|
Safa AR, Kamocki K, Saadatzadeh MR, Bijangi-Vishehsaraei K. c-FLIP, a Novel Biomarker for Cancer Prognosis, Immunosuppression, Alzheimer's Disease, Chronic Obstructive Pulmonary Disease (COPD), and a Rationale Therapeutic Target. BIOMARKERS JOURNAL 2019; 5:4. [PMID: 32352084 PMCID: PMC7189798 DOI: 10.36648/2472-1646.5.1.59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dysregulation of c-FLIP (cellular FADD-like IL-1β-converting enzyme inhibitory protein) has been shown in several diseases including cancer, Alzheimer's disease, and chronic obstructive pulmonary disease (COPD). c-FLIP is a critical anti-cell death protein often overexpressed in tumors and hematological malignancies and its increased expression is often associated with a poor prognosis. c-FLIP frequently exists as long (c-FLIPL) and short (c-FLIPS) isoforms, regulates its anti-cell death functions through binding to FADD (FAS associated death domain protein), an adaptor protein known to activate caspases-8 and -10 and links c-FLIP to several cell death regulating complexes including the death-inducing signaling complex (DISC) formed by various death receptors. c-FLIP also plays a critical role in necroptosis and autophagy. Furthermore, c-FLIP is able to activate several pathways involved in cytoprotection, proliferation, and survival of cancer cells through various critical signaling proteins. Additionally, c-FLIP can inhibit cell death induced by several chemotherapeutics, anti-cancer small molecule inhibitors, and ionizing radiation. Moreover, c-FLIP plays major roles in aiding the survival of immunosuppressive tumor-promoting immune cells and functions in inflammation, Alzheimer's disease (AD), and chronic obstructive pulmonary disease (COPD). Therefore, c-FLIP can serve as a versatile biomarker for cancer prognosis, a diagnostic marker for several diseases, and an effective therapeutic target. In this article, we review the functions of c-FLIP as an anti-apoptotic protein and negative prognostic factor in human cancers, and its roles in resistance to anticancer drugs, necroptosis and autophagy, immunosuppression, Alzheimer's disease, and COPD.
Collapse
Affiliation(s)
- Ahmad R Safa
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, USA
| | - Krzysztof Kamocki
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, USA
| | - M Reza Saadatzadeh
- Department of Neurosurgery, Indiana University School of Medicine, Indianapolis, USA
| | | |
Collapse
|
4
|
Kim EA, Kim SW, Nam J, Sung EG, Song IH, Kim JY, Kwon TK, Lee TJ. Inhibition of c-FLIPL expression by miRNA-708 increases the sensitivity of renal cancer cells to anti-cancer drugs. Oncotarget 2017; 7:31832-46. [PMID: 27092874 PMCID: PMC5077980 DOI: 10.18632/oncotarget.7149] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 01/23/2016] [Indexed: 12/23/2022] Open
Abstract
Dysregulation of the anti-apoptotic protein, cellular FLICE-like inhibitory protein (c-FLIP), has been associated with tumorigenesis and chemoresistance in various human cancers. Therefore, c-FLIP is an excellent target for therapeutic intervention. MicroRNAs (miRNAs) are small non-coding RNAs that are involved in tumorigenesis, tumor suppression, and resistance or sensitivity to anti-cancer drugs. However, whether miRNAs can suppress c-FLIPL expression in cancer cells is unclear. The aim of this study was to identify miRNAs that could inhibit the growth of renal cancer cells and induce cell death by inhibiting c-FLIPL expression. We found that MiRNA-708 and c-FLIPL expression were inversely correlated. While c-FLIPL expression was upregulated, miRNA-708 was rarely expressed in renal cancer cells. Luciferase reporter assays demonstrated that miRNA-708 negatively regulated c-FLIPL expression by binding to the miRNA-708 binding site in the 3' untranslated region (3'UTR) of c-FLIPL. Ectopic expression of miRNA-708 increased the accumulation of sub-G1 populations and cleavage of procaspase-3 and PARP, which could be prevented by pretreatment with the pan-caspase inhibitor, Z-VAD. Ectopic expression of miRNA-708 also increased the sensitivity to various apoptotic stimuli such as tumor necrosis factor-related apoptosis-inducing ligand, doxorubicin (Dox), and thapsigargin in Caki cells. Interestingly, miRNA-708 specifically repressed c-FLIPL without any change in c-FLIPs expression. In contrast, inhibition of endogenous miRNA-708 using antago-miRNAs resulted in an increase in c-FLIPL protein expression. The expression of c-FLIPL was upregulated in renal cell carcinoma (RCC) tissues compared to normal tissues. In contrast, miRNA-708 expression was reduced in RCC tissues. Finally, miRNA-708 enhanced the tumor-suppressive effect of Dox in a xenograft model of human RCC. In conclusion, miRNA-708 acts as a tumor suppressor because it negatively regulates the anti-apoptotic protein c-FLIPL and regulates the sensitivity of renal cancer cells to various apoptotic stimuli.
Collapse
Affiliation(s)
- Eun-Ae Kim
- Department of Anatomy, College of Medicine, Yeungnam University, Nam-gu, Daegu, Republic of Korea
| | - Sang-Woo Kim
- Department of Biological Sciences, Pusan National University, Busan, Republic of Korea
| | - Jehyun Nam
- Department of Biological Sciences, Pusan National University, Busan, Republic of Korea
| | - Eon-Gi Sung
- Department of Anatomy, College of Medicine, Yeungnam University, Nam-gu, Daegu, Republic of Korea
| | - In-Hwan Song
- Department of Anatomy, College of Medicine, Yeungnam University, Nam-gu, Daegu, Republic of Korea
| | - Joo-Young Kim
- Department of Anatomy, College of Medicine, Yeungnam University, Nam-gu, Daegu, Republic of Korea
| | - Taeg Kyu Kwon
- Department of Immunology, School of Medicine, Keimyung University, Dalseo-Gu, Daegu, Republic of Korea
| | - Tae-Jin Lee
- Department of Anatomy, College of Medicine, Yeungnam University, Nam-gu, Daegu, Republic of Korea
| |
Collapse
|
5
|
Tian F, Hu Y, Sun X, Lu G, Li Y, Yang J, Tao J. Suppression of c‑FLIPL promotes JNK activation in malignant melanoma cells. Mol Med Rep 2016; 13:2904-8. [PMID: 26847085 DOI: 10.3892/mmr.2016.4856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 01/11/2016] [Indexed: 11/05/2022] Open
Abstract
The up‑regulation of cellular Fas‑associated death domain‑like interleukin‑1β‑converting enzyme (FLICE)‑like inhibitory protein (c‑FLIP) has been reported in various tumor types, and has been previously shown to be associated with the clinicopathological features of melanoma. To assess its potential role in cancer therapy, the present study evaluated the effects of short hairpin (sh)RNAs of different c‑FLIP isoforms on cellular proliferation and c‑Jun N‑terminal kinase (JNK) signaling. Human c‑FLIP shRNA plasmids were constructed and transfected into the A875 melanoma cell line. It was observed that c‑FLIP shRNA exhibited strong inhibitory effects against the levels of phosphorylated‑JNK and inhibited cellular proliferation in A875 cells. Thus, this indicated that c‑FLIP long form shRNA serves a specific inhibitory role in cellular proliferation through inducing the activation of the JNK pathway in A875 cells. The present study provided insight into the development of RNAi based therapies for melanoma.
Collapse
Affiliation(s)
- Fen Tian
- Department of Dermatology, Sixth People's Hospital of Zhengzhou, Zhengzhou, Henan 450015, P.R. China
| | - Yange Hu
- Department of Dermatology, Sixth People's Hospital of Zhengzhou, Zhengzhou, Henan 450015, P.R. China
| | - Xixi Sun
- Department of Dermatology, Sixth People's Hospital of Zhengzhou, Zhengzhou, Henan 450015, P.R. China
| | - Gaihui Lu
- Department of Dermatology, Sixth People's Hospital of Zhengzhou, Zhengzhou, Henan 450015, P.R. China
| | - Yan Li
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jing Yang
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Juan Tao
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| |
Collapse
|
6
|
Abstract
Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP(L)), short (c-FLIP(S)), and c-FLIP(R) splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP(L) and c-FLIP(S) are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP(L) in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP(L) and c-FLIP(S) splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function.
Collapse
|
7
|
Tan K, Goldstein D, Crowe P, Yang JL. Uncovering a key to the process of metastasis in human cancers: a review of critical regulators of anoikis. J Cancer Res Clin Oncol 2013; 139:1795-805. [PMID: 23912151 DOI: 10.1007/s00432-013-1482-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/19/2013] [Indexed: 12/28/2022]
Abstract
PURPOSE Anoikis ('homelessness' in Greek) is a form of apoptosis following the detachment of cells from the appropriate extracellular matrix (Chiarugi and Giannoni in Biochem Pharmacol 76:1352-1364, 2008). Resistance to anoikis is a critical mediator of metastasis in cancer by enabling cancer cells to survive during invasion and transport in the blood and lymph. Numerous regulators and mechanisms of anoikis in human cancer have been proposed to date. Consequently, the identification of key regulators of anoikis that can be targeted to at least partially restore anoikis sensitivity in cancer cells is important in the development of therapies to treat metastatic cancer. METHODS A literature search focusing on the regulators of anoikis in human cancer was performed on the Medline, Embase and Scopus databases. RESULTS Mcl-1, Cav-1, Bcl-(xL), cFLIP, 14-3-3ζ and Bit1 appear to regulate anoikis in human cancer by participating in the intrinsic apoptotic pathway, extrinsic apoptotic pathway or caspase-independent pathways. Mcl-1, Cav-1, Bcl-(xL), cFLIP and 14-3-3ζ are suppressors of anoikis, and their upregulation confers anoikis resistance to cancer cells. Bit1 is a promoter of anoikis and is downregulated to confer anoikis resistance in metastatic cancer. CONCLUSION Anoikis is a complex process involving the crosstalk between different signalling pathways. The dysregulated expression of key regulators of anoikis that participate in these signalling pathways promotes anoikis resistance in human cancer. These regulators of anoikis might therefore be the targets for developing therapies to overcome anoikis resistance in metastatic cancer.
Collapse
Affiliation(s)
- Kevin Tan
- Adult Cancer Program, Sarcoma and Nano-Oncology Research Group, Faculty of Medicine, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales, Room 209, Sydney, NSW, 2052, Australia
| | | | | | | |
Collapse
|
8
|
Tian F, Lu JJ, Wang L, Li L, Yang J, Li Y, Liu YQ, Shen GX, Tu YT, Tao J. Expression of c-FLIP in malignant melanoma, and its relationship with the clinicopathological features of the disease. Clin Exp Dermatol 2011; 37:259-65. [DOI: 10.1111/j.1365-2230.2011.04238.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
9
|
Plati J, Bucur O, Khosravi-Far R. Apoptotic cell signaling in cancer progression and therapy. Integr Biol (Camb) 2011; 3:279-96. [PMID: 21340093 DOI: 10.1039/c0ib00144a] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Apoptosis is a tightly regulated cell suicide program that plays an essential role in the development and maintenance of tissue homeostasis by eliminating unnecessary or harmful cells. Impairment of this native defense mechanism promotes aberrant cellular proliferation and the accumulation of genetic defects, ultimately resulting in tumorigenesis, and frequently confers drug resistance to cancer cells. The regulation of apoptosis at several levels is essential to maintain the delicate balance between cellular survival and death signaling that is required to prevent disease. Complex networks of signaling pathways act to promote or inhibit apoptosis in response to various cues. Apoptosis can be triggered by signals from within the cell, such as genotoxic stress, or by extrinsic signals, such as the binding of ligands to cell surface death receptors. Various upstream signaling pathways can modulate apoptosis by converging on, and thereby altering the activity of, common central control points within the apoptotic signaling pathways, which involve the BCL-2 family proteins, inhibitor of apoptosis (IAP) proteins, and FLICE-inhibitory protein (c-FLIP). This review highlights the role of these fundamental regulators of apoptosis in the context of both normal apoptotic signaling mechanisms and dysregulated apoptotic pathways that can render cancer cells resistant to cell death. In addition, therapeutic strategies aimed at modulating the activity of BCL-2 family proteins, IAPs, and c-FLIP for the targeted induction of apoptosis are briefly discussed.
Collapse
Affiliation(s)
- Jessica Plati
- Department of Pathology, Harvard Medical School, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215, USA
| | | | | |
Collapse
|
10
|
Bijangi-Vishehsaraei K, Huang S, Safa AR, Saadatzadeh MR, Murphy MP. 4-(4-Chloro-2-methylphenoxy)-N-hydroxybutanamide (CMH) targets mRNA of the c-FLIP variants and induces apoptosis in MCF-7 human breast cancer cells. Mol Cell Biochem 2010; 342:133-142. [PMID: 20446019 DOI: 10.1007/s11010-010-0477-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 04/17/2010] [Indexed: 12/30/2022]
Abstract
Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor for the tumor necrosis factor-related apoptosis-inducing ligand TRAIL and in drug resistance in human malignancies. c-FLIP is an antagonist of caspases-8 and -10, which inhibits apoptosis and is expressed as long (c-FLIP(L)) and short (c-FLIP(S)) splice forms. c-FLIP is often overexpressed in various human cancers, including breast cancer. Several studies have shown that silencing c-FLIP by specific siRNAs sensitizes cancer cells to TRAIL and anticancer agents. However, systemic use of siRNA as a therapeutic agent is not practical at present. In order to reduce or inhibit c-FLIP expression, small molecules are needed to allow targeting c-FLIP without inhibiting caspases-8 and -10. We used a small molecule inhibitor of c-FLIP, 4-(4-chloro-2-methylphenoxy)-N-hydroxybutanamide (CMH), and show that CMH, but not its inactive analog, downregulated c-FLIP(L) and c-FLIP(S) mRNA and protein levels, caused poly(ADP-ribose) polymerase (PARP) degradation, reduced cell survival, and induced apoptosis in MCF-7 breast cancer cells. These results revealed that c-FLIP is a critical apoptosis regulator that can serve as a target for small molecule inhibitors that downregulate its expression and serve as effective targeted therapeutics against breast cancer cells.
Collapse
Affiliation(s)
- Khadijeh Bijangi-Vishehsaraei
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202, USA
| | - Su Huang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202, USA
| | - Ahmad R Safa
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indiana University School of Medicine, 980 W. Walnut Street, R3-C524, Indianapolis, IN 46202, USA
| | | | - Michael P Murphy
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| |
Collapse
|
11
|
Day TW, Huang S, Safa AR. c-FLIP knockdown induces ligand-independent DR5-, FADD-, caspase-8-, and caspase-9-dependent apoptosis in breast cancer cells. Biochem Pharmacol 2008; 76:1694-704. [PMID: 18840411 DOI: 10.1016/j.bcp.2008.09.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 09/02/2008] [Accepted: 09/05/2008] [Indexed: 11/18/2022]
Abstract
Cellular-FLICE inhibitory protein (c-FLIP) is an inhibitor of apoptosis downstream of the death receptors Fas, DR4, and DR5, and is expressed as long (c-FLIP(L)) and short (c-FLIP(S)) splice forms. We found that the knockdown of c-FLIP using small interfering RNA (siRNA) triggered ligand-independent caspase-8- and -9-dependent spontaneous apoptosis and decreased the proliferation of MCF-7 breast cancer cells. Further analysis revealed that an apoptotic inhibitory complex (AIC) comprised of DR5, FADD, caspase-8, and c-FLIP(L) exists in MCF-7 cells, and the absence of c-FLIP(L) from this complex induces DR5- and FADD-mediated caspase-8 activation in the death inducing signaling complex (DISC). c-FLIP(S) was not detected in the AIC, and using splice form-specific siRNAs we showed that c-FLIP(L) but not c-FLIP(S) is required to prevent spontaneous death signaling in MCF-7 cells. These results clearly show that c-FLIP(L) prevents ligand-independent death signaling and provides direct support for studying c-FLIP as a relevant therapeutic target for breast cancers.
Collapse
Affiliation(s)
- Travis W Day
- Department of Pharmacology and Toxicology, Indiana University Simon Cancer Center, Indiana University School of Medicine, 1044 West Walnut Street R4-119, Indianapolis, IN 46202, USA
| | | | | |
Collapse
|
12
|
Heikaus S, Kempf T, Mahotka C, Gabbert HE, Ramp U. Caspase-8 and its inhibitors in RCCs in vivo: the prominent role of ARC. Apoptosis 2008; 13:938-49. [PMID: 18516683 DOI: 10.1007/s10495-008-0225-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Activation of the initiator-caspase, caspase-8 is under tight control of multiple antiapoptotic regulators including ARC, cFlip(S), cFlip(L) and PED/PEA-15. Since there is little data regarding the expression of caspase-8 and its antiapoptotic regulators in human tumours in vivo, we analysed their expression in renal cell carcinomas (RCCs) to identify which of these genes might be crucial for the well known impaired apoptosis and--as a result--resistance towards chemotherapy and ionizing radiation of RCCs. Caspase-8, cFlip(S), cFlip(L) and PED/PEA-15 mRNA expression was significantly increased only in early stages of RCCs compared to non-neoplastic renal tissue. In contrast, ARC mRNA expression was significantly increased in RCCs of all stages without differences between the tumour stages and grades. Importantly, the relative mRNA expression ratio between ARC and caspase-8 was significantly increased during carcinogenesis and tumour progression. In contrast, the relative mRNA expression ratio between cFlip(S), cFlip(L) or PED/PEA-15 and caspase-8 remained constant during all tumour stages. In conclusion, our analysis revealed that ARC is the only caspase-8 inhibiting regulator being constantly overexpressed in RCCs. Furthermore, the balance between antiapoptotic ARC and proapoptotic caspase-8 is the only one to be disturbed during carcinogenesis and tumour progression of RCCs. This inhibition of Caspase-8 might therefore be one example for the multiple antiapoptotic functions of ARC in RCCs possibly contributing to the marked resistance of RCCs towards radio- and chemotherapy and reflects a shift of gene expression towards a more antiapoptotic context in RCCs.
Collapse
Affiliation(s)
- Sebastian Heikaus
- Institute of Pathology, Heinrich-Heine University Hospital, Moorenstrasse 5, 40225 Duesseldorf, Germany,
| | | | | | | | | |
Collapse
|
13
|
Safa AR, Day TW, Wu CH. Cellular FLICE-like inhibitory protein (C-FLIP): a novel target for cancer therapy. Curr Cancer Drug Targets 2008; 8:37-46. [PMID: 18288942 DOI: 10.2174/156800908783497087] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cellular FLICE-like inhibitory protein (c-FLIP) has been identified as a protease-dead, procaspase-8-like regulator of death ligand-induced apoptosis, based on observations that c-FLIP impedes tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis by binding to FADD and/or caspase-8 or -10 in a ligand-dependent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. c-FLIP is a family of alternatively spliced variants, and primarily exists as long (c-FLIP(L)) and short (c-FLIP(S)) splice variants in human cells. Although c-FLIP has apoptogenic activity in some cell contexts, which is currently attributed to heterodimerization with caspase-8 at the DISC, accumulating evidence indicates an anti-apoptotic role for c-FLIP in various types of human cancers. For example, small interfering RNAs (siRNAs) that specifically knocked down expression of c-FLIP(L) in diverse human cancer cell lines, e.g., lung and cervical cancer cells, augmented TRAIL-induced DISC recruitment, and thereby enhanced effector caspase stimulation and apoptosis. Therefore, the outlook for the therapeutic index of c-FLIP-targeted drugs appears excellent, not only from the efficacy observed in experimental models of cancer therapy, but also because the current understanding of dual c-FLIP action in normal tissues supports the notion that c-FLIP-targeted cancer therapy will be well tolerated. Interestingly, Taxol, TRAIL, as well as several classes of small molecules induce c-FLIP downregulation in neoplastic cells. Efforts are underway to develop small-molecule drugs that induce c-FLIP downregulation and other c-FLIP-targeted cancer therapies. In this review, we assess the outlook for improving cancer therapy through c-FLIP-targeted therapeutics.
Collapse
Affiliation(s)
- Ahmad R Safa
- Department of Pharmacology and Toxicology, Indiana University Cancer Center, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN 46202, USA.
| | | | | |
Collapse
|
14
|
Ryang DY, Joo YE, Chung KM, Lim SR, Jeong HK, Kim HI, Lee WS, Park CH, Kim HS, Choi SK, Rew JS, Lee JH, Park CS. Expression of c-FLIP in gastric cancer and its relation to tumor cell proliferation and apoptosis. Korean J Intern Med 2007; 22:263-9. [PMID: 18309685 PMCID: PMC2687667 DOI: 10.3904/kjim.2007.22.4.263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The expression of c-FLIP (cellular Fas-associated death domain-like interleukin-1 beta-converting enzyme (FLICE)-inhibitory protein), which is a member of the family of inhibitors of apoptosis, has been associated with tumor development and progression. The aim of this study was to evaluate the expression of c-FLIP in gastric cancer and its correlation with tumor cell proliferation, apoptosis and the clinicopathologic features. METHODS Immunohistochemical staining with anti-c-FLIP antibody was performed in 98 tissue samples obtained from gastric cancer patients who underwent surgical treatment. The apoptotic cells were visualized by terminal deoxynucleotidyl transferase (TdT) mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL), and the proliferative cells were visualized by staining with Ki-67 antibody. RESULTS The positive expression of c-FLIP in the gastric cancer tissues was demonstrated in 57.1% of the cases. The expression of c-FLIP was increased in the gastric cancer tissues compared with the matched normal gastric mucosa. The expression of c-FLIP was significantly associated with histologic differentiation (p = 0.038). However, there was no association between the c-FLIP expression and the other clinicopathological parameters, including patient survival. The Ki-67 labeling index (KI) for the 98 tumors ranged from 7.6 to 85.0 with a mean KI of 50.4 +/- 15.7. The mean KI value of the c-FLIP positive tumors was 54.1 +/- 15.3 and this was significantly higher than that of the c-FLIP negative tumors (p = 0.005). The apoptotic index (AI) for the 98 tumors ranged from 0.0 to 10.0 with a mean AI of 7.4 +/- 2.3. There was no significant difference between the c-FLIP expression and the AI (p = 0.347). CONCLUSIONS These results suggest that the c-FLIP expression may be associated with tumor cell proliferation of gastric cancer.
Collapse
Affiliation(s)
- Dae-Yeul Ryang
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Young-Eun Joo
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Kyoung-Myeun Chung
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Sung-Ryoun Lim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Hye-Kyong Jeong
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Hyung-Il Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Wan-Sik Lee
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Chang-Hwan Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Hyun-Soo Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Sung-Kyu Choi
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jong-Sun Rew
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jae-Hyuk Lee
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| | - Chang-Soo Park
- Department of Pathology, Chonnam National University Medical School, Gwangju, Korea
| |
Collapse
|