
Clinical Cancer Research 13, 2313-2317, April 15, 2007. doi: 10.1158/1078-0432.CCR-06-2774
© 2007 American Association for Cancer Research
Targeting TRAIL Agonistic Receptors for Cancer Therapy
Carmelo Carlo-Stella1,3,
Cristiana Lavazza1,3,
Alberta Locatelli2,
Lucia Viganò2,
Alessandro M. Gianni1,3 and
Luca Gianni2
Authors' Affiliations: 1 "Cristina Gandini" Medical Oncology Unit and 2 Medical Oncology 1, Istituto Nazionale Tumori, and 3 Medical Oncology, University of Milan, Milan, Italy
Requests for reprints: Alessandro M. Gianni, "Cristina Gandini" Medical Oncology Unit, Istituto Nazionale Tumori, Via Venezian, 1-20133 Milan, Italy. Phone: 39-2-2390-2532; Fax: 39-2-2390-3461; E-mail: Alessandro.Gianni{at}unimi.it.
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Abstract
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Based on preclinical studies demonstrating that tumor necrosis factorrelated apoptosis-inducing ligand (TRAIL) exerts a potent and cancer cellspecific proapoptotic activity, recombinant TRAIL as well as agonistic antiTRAIL-R1 and antiTRAIL-R2 antibodies recently entered clinical trials. Additionally, gene therapy approaches using TRAIL-encoding adenovirus (Ad-TRAIL) are currently being developed to overcome the limitations inherent to TRAIL receptor targeting, i.e., pharmacokinetic of soluble TRAIL, pattern of receptor expression, and tumor cell resistance. To optimize gene therapy approaches, CD34+ cells transduced with Ad-TRAIL (CD34-TRAIL+) have been investigated as cellular vehicles for TRAIL delivery. Transduced cells exhibit a potent tumor killing activity on a variety of tumor cell types both in vitro and in vivo and are also cytotoxic against tumor cells resistant to soluble TRAIL. Studies in tumor-bearing nonobese diabetic/severe combined immunodeficient mice suggest that the antitumor effect of CD34-TRAIL+ cells is mediated by both direct tumor cell killing due to apoptosis and indirect tumor cell killing due to vascular-disrupting mechanisms. The clinical translation of cell and gene therapy approaches represent a challenging strategy that might achieve systemic tumor targeting and increased intratumor delivery of the therapeutic agent.
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Background
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Dysregulated apoptosis plays a key role in the pathogenesis and progression of neoplastic disorders, allowing tumor cells to survive beyond their normal life span and to eventually acquire chemoradioresistance (1, 2). Thus, apoptotic pathways represent attractive therapeutic targets for restoring apoptosis sensitivity of malignant cells or activating agonists of apoptosis. To modulate apoptotic genes and proteins, several strategies can be envisaged that target either the mitochondria-dependent (intrinsic) or the death receptor-dependent (extrinsic) pathways of apoptosis (3). Because of the ability of death receptor ligands to induce death in susceptible cell types, there has been considerable interest in the physiologic roles and therapeutic potential of these cytokines as anticancer agents. Death receptor ligands of the tumor necrosis factor
(TNF
) superfamily are type II transmembrane proteins that signal to target cells on cell-cell contact, or after protease-mediated release to the extracellular space (4). Four members of this family, namely, Fas ligand, TNF
, TL1A (a recently discovered TNF-like ligand), and TNFrelated apoptosis-inducing ligand (TRAIL), stand out because of their ability to induce cell death (5, 6).
TRAIL, in its soluble form, is emerging as an attractive anticancer agent because of its cancer cell specificity and potent antitumor activity. In vitro several sets of evidence show that TRAIL selectively induces apoptosis in a variety of transformed cell lines (79); in vivo administration of TRAIL to mice exerts a remarkable activity against tumor xenografts of various cancers (1015). Unlike other apoptosis-inducing TNF family members, soluble TRAIL seems to be inactive against normal healthy tissue (10), and reports in which TRAIL induces apoptosis in normal cells could be attributed to the specific preparations of TRAIL used in the experiments (16). The physiologic functions of TRAIL are not yet fully understood, but mouse gene knock-out studies indicate that this agent has an important role in antitumor surveillance by immune cells, mediates thymocyte apoptosis, and is important in the induction of autoimmune diseases (1719). TRAIL signals by interacting with its receptors. Thus far, five receptors have been identified, namely, the two agonistic receptors, TRAIL-R1 (20) and TRAIL-R2 (21), and the three antagonistic receptors (22) TRAIL-R3 (23), TRAIL-R4 (24), and osteoprotegerin (OPG; ref. 25). Both TRAIL-R1 and TRAIL-R2 are type I transmembrane proteins containing a cytoplasmic death domain (DD) motif that engage apoptotic machinery upon ligand binding (7), whereas the other three receptors either act as decoys or transduce antiapoptotic signals (26). TRAIL-R3 and TRAIL-R4 have close homology to the extracellular domains of agonistic receptors. TRAIL-R4 has a truncated, nonfunctional cytoplasmic DD, whereas TRAIL-R3 exists on the plasma membrane as a glycophospholipid-anchored protein lacking the cytosolic tail. The physiologic relevance of OPG as a soluble receptor for TRAIL is unclear, but a recent study suggests that cancer-derived OPG may be an important survival factor in hormone-resistant prostate cancer cells (27).
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TRAIL-Induced Apoptosis Signaling
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TRAIL forms homotrimers that bind three receptor molecules, each at the interface between two of its subunits. A Zn atom bound to cysteine residues in the trimeric ligand is essential for trimer stability and optimal biological activity. Binding of TRAIL to the extracellular domain of agonistic receptors results in the trimerization of the receptors and clustering of the intracellular DDs, which leads to the recruitment of the adaptor molecule Fas-associated protein with death domain (FADD; Fig. 1
). Subsequently, FADD recruits initiator caspase-8 and caspase-10, leading to the formation of the death-inducing signaling complex (DISC), in which initiator caspases autoactivate by proteolysis. Once they become enzymatically active, caspase-8 and/or caspase-10 are released from the DISC and signal through two different proteolytic pathways that converge on caspase-3 and lead to cellular disassembly (28). In type I cells, activation of initiator caspases upon death receptor ligation is sufficient to directly activate downstream effector caspases, such as caspase-3 and/or caspase-7 (29). This extrinsic pathway is independent of the mitochondria and is not blocked by overexpression of Bcl-2. In type II cells, the commitment from death receptor ligation to apoptosis is less direct (29). The amount of initially cleaved caspase-8 and/or caspase-10 is not enough to directly trigger effector caspase activation. Consequently, apoptotic signaling requires an amplification loop by mitochondrial pathway engagement through caspase-8mediated cleavage of Bid (BH3 interacting DD agonist), which, in turn, induces the cytosolic Bcl-2 family member Bcl-2associated X protein (Bax) and/or the loosely bound mitochondrial homologue Bcl-2 antagonist/killer (Bak) to insert into the mitochondrial membrane, where they contribute to the mitochondrial release of cytochrome c (30). In the cytosol, cytochrome c binds the adaptor protein apoptotic protease activating factor 1 (Apaf-1) to form an apoptosome with recruitment and activation of the apoptosis-initiating caspase-9, which proteolytically activates additional caspase-3. These events are further amplified by apoptogenic factors released from the mitochondrial space, including Smac/DIABLO [second mitochondrial activator of caspases/direct IAP-binding protein with low isoelectric point (pI)], which displaces the X-chromosomelinked inhibitor of apoptosis protein (XIAP) from caspase-3, caspase-7, and caspase-9 (31).

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Fig. 1. Crosstalk between apoptosis signaling pathways following activation of death receptors. Death receptors trigger the cell-intrinsic pathway by activation of caspase-8 and caspase-10. Cleaved BID interacts with Bax and Bak, which in turn, activate caspase-9 and caspase-3, resulting in apoptosis induction through the cell-extrinsic pathway. In type I cells, death-receptor engagement of the cell-extrinsic pathway is sufficient for commitment to apoptotic death. In type II cells, commitment to apoptosis requires the amplification of the death-receptor signal by the cell-intrinsic pathway. Because death-receptor targeting and conventional agents induce tumor cell apoptosis through different signaling pathways, combinations of the two approaches might facilitate the killing of tumor cells that resist death induction through either one of the pathways.
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Clinical-Translational Advances
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Apoptosis induction in response to most DNA-damaging drugs usually requires the function of the tumor suppressor p53, which engages primarily the intrinsic apoptotic-signaling pathway. In most human cancers, however, tumor progression as well as conventional treatments eventually select for tumor cells in which p53 is inactivated, resulting in resistance to therapy. Activation of the DD-containing TRAIL receptors represents an opportunity to exploit the extrinsic apoptotic pathway to destroy cancer cells, regardless of p53 status, and therefore, it might be a useful therapeutic strategy, particularly in cells in which the p53-response pathway has been inactivated, thus helping to circumvent resistance to chemo- and radiotherapy. Based on promising preclinical observations, recombinant TRAIL as well as agonistic antiTRAIL-R1 and antiTRAIL-R2 antibodies recently entered clinical trials (Fig. 2
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Fig. 2. Therapeutic approaches to death receptor activation. TRAIL-R1 and TRAIL-R2 can be engaged by soluble TRAIL as well as the membrane-bound form of the ligand. Agonistic antibodies selectively bind either TRAIL-R1 or TRAIL-R2.
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Recombinant TRAIL, a receptor agonist that directly activates both TRAIL-R1 and TRAIL-R2, is currently being codeveloped by Genentech (San Francisco, CA) and Amgen (Thousand Oaks, CA) as a targeted therapy for solid tumors and hematologic malignancies. Phase I studies using recombinant TRAIL have been initiated, but results are not yet available (32). HGS-ETR1 (Mapatumumab; Human Genome Sciences, Rockville, MD) is a fully human agonistic monoclonal antibody that targets TRAIL-R1. HGS-ETR1 is currently in phase II clinical development as a single agent in patients with nonsmall cell lung cancer and colorectal cancer (reviewed in ref. 33). Clinical activity of HGS-ETR1 is suggested by three partial responses observed in a recently reported multicenter phase II trial in relapsed non-Hodgkin lymphoma receiving either 3 or 10 mg/kg HGS-ETR1 every 3 weeks for six cycles or until disease progression (33). Additional phase Ib trials with HGS-ETR1 in combination with carboplatin/paclitaxel and cisplatin/gemcitabine have been initiated in patients with advanced solid malignancies (33). Fully human antibodies to TRAIL-R2 (HGS-ETR2 and HGS-TR2J; Human Genome Sciences) have also entered the clinic and are currently in phase I clinical development (33). Agonist monoclonal antibodies specifically bind and activate TRAIL-R1 (HGS-ETR1) or TRAIL-R2 (HGSETR2 and HGS-TR2J). Monoclonal antibodies restrict the therapeutic target to tumors with a distinct receptor expression profile, whereas soluble TRAIL interacts with both TRAIL-R1 and TRAIL-R2 as well as the decoy receptors. Therefore, soluble TRAIL may either have a wider therapeutic spectrum or a narrower and more unpredictable therapeutic window compared with the highly specific antibodies. The biological relevance of the decoy receptors, their ability to inhibit TRAIL signaling, and the expression profile of the decoy receptors have not yet been fully investigated.
Tumor cells may have an impaired apoptotic response to TRAIL because of resistance mechanism(s) occurring at different points along the TRAIL signaling pathway (34). Dysfunctions due to mutations and defects in either the death receptors TRAIL-R1 or TRAIL-R2, as well as the adaptor protein FADD and caspase-8, can lead to TRAIL resistance because of their essential role in the DISC complex assembly (20, 2224). Overexpression of cellular FADD-like interleukin-1ßconverting enzyme-inhibitory protein (cFLIP) correlates with TRAIL resistance in several types of cancer. Overexpression of Bcl-2 or Bcl-XL, loss of Bax or Bak function, high expression of inhibitor of apoptosis proteins, and reduced release of Smac/DIABLO from the mitochondria to the cytosol have all been reported to result in TRAIL resistance in mitochondria-dependent type II cancer cells (11, 12, 34). Finally, activation of different subunits of mitogen-activated protein kinases or nuclear factor-
B can lead to development of either TRAIL resistance or apoptosis in certain types of cancer cells (22, 34).
The mechanism(s) to overcome TRAIL resistance remains largely unclear. A prolonged exposure to the drug or very high doses of TRAIL might be required to overcome resistance (3538). Because of the short half-life of TRAIL in plasma (10) and rapid elimination (15), however, achieving prolonged exposure at high concentrations is difficult. Despite in vivo studies using a trimerized (15) or a nontagged (10, 39) form of TRAIL having shown a good toxicity profile of the molecule, organ toxicity might occur when using high doses of soluble TRAIL. In experimental anticancer treatments, the response to TRAIL-induced apoptosis was significantly increased on coadministration of DNA-damaging chemotherapeutic drugs because of up-regulation of TRAIL-R1 and/or TRAIL-R2 (40, 41). In addition, irradiation seems to specifically up-regulate TRAIL-R2 receptor expression, and combining irradiation with TRAIL treatment has an additive or synergistic effect (42). Alternatively, up-regulation of TRAIL-R1 or TRAIL-R2 using small molecules, such as the proteasome inhibitor bortezomib (43) or inhibitors of histone deacetylase (44) might allow to overcome TRAIL resistance.
Several gene therapy approaches are currently being developed to specifically target tumor cells and overcome the limitations inherent to death receptor targeting, i.e., pharmacokinetic, toxicity profile, pattern of receptor expression, tumor cell resistance. A TRAIL-expressing adenoviral vector (Ad-TRAIL) has been recently shown to cause direct tumor cell killing, as well as a potent bystander effect through the presentation of TRAIL by transduced normal cells (45). Using Ad-TRAIL might be an alternative to delivery of systemic soluble TRAIL that may lead to better tumor cell targeting and increased tumoricidal activity (4549). Optimal Ad-TRAILbased gene therapy, however, requires efficient infection of target tumor cells and avoidance of immune clearance (50). In addition, safety and toxicity issues linked to the systemic vector administration force cancer researchers to adopt an intratumoral injection of Ad-TRAIL, which results in local therapeutic activity with limited value for treating disseminated tumors.
To optimize the use of TRAIL-encoding adenovectors, thereby allowing the systemic delivery of TRAIL, we explored and recently described a cell therapy approach using a replication-deficient Ad-TRAIL encoding a full-length membrane-bound TRAIL (mTRAIL) to transduce CD34+ cells (CD34-TRAIL+; ref. 51; Fig. 2). Gene-modified CD34+ cells represent optimal vehicles of antitumor molecules. In fact, they can migrate from the bloodstream into tumor tissues because of the expression of adhesion receptors that specifically interact with counter-receptors on endothelial cells in the tumor microenvironment (5254). Additionally, up-regulation of inflammatory chemoattractants in the tumor microenvironment provides a permissive environment that allows for homing of systemically delivered CD34-TRAIL+ cells and efficient tumor targeting (55). In vitro CD34-TRAIL+ cells exhibited high killing activity on a variety of tumor cell types, including lymphoma, multiple myeloma, as well as epithelial cancers, and most importantly, mTRAIL-armed cells were highly cytotoxic against tumor cells resistant to soluble TRAIL (51). Thus, the membrane-bound form of the ligand is capable of triggering apoptosis more efficiently than soluble TRAIL and overcoming tumor resistance to the soluble ligand. This peculiar functional property of mTRAIL might be due to a differential activation of TRAIL-R1 and TRAIL-R2 by soluble and membrane TRAIL as suggested by studies showing that TRAIL-R1 signals apoptosis on triggering by both the soluble and membrane-bound form of the ligand, whereas TRAIL-R2 becomes only activated by mTRAIL or soluble TRAIL cross-linked by antibodies (56, 57). CD34-TRAIL+ cells also showed potent in vivo tumoricidal efficacy in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice xenografted with soluble TRAIL-sensitive and TRAIL-resistant tumors. Repeated dosing with mTRAIL-armed cells resulted in a significantly prolonged survival of tumor-bearing mice (51). Histologic analysis of tumor nodules growing in vivo in NOD/SCID mice showed an efficient tumor homing of transduced cells and a high level of expression of the agonistic TRAIL-R2 receptor by tumor endothelial cells (51). Indeed, injection of CD34-TRAIL+ cells resulted in extensive damage of the tumor vasculature followed by hemorrhagic necrosis that exhibited a perivascular distribution, suggesting that CD34-TRAIL+ cells might be an efficient vehicle for mTRAIL delivery to tumors, where they exert a potent antitumor effect mediated by both direct tumor cell killing due to apoptosis and indirect tumor cell killing due to vascular-disrupting mechanisms.
Because death receptor activation can instruct malignant cells to undergo apoptosis independent of p53, targeting death receptors with TRAIL-targeting therapeutics is a rational therapeutic strategy against cancer. According to experimental data obtained thus far, TRAIL-targeting therapeutics possess considerable and specific antitumor therapeutic activity both when used alone as well as in combination with nonspecific cytotoxic agents, radiation, and other target-based therapeutics. In a way that recapitulates the dilemmas faced with targeted agents in clinical development, the ideal tumor types to select to achieve a proof of principle of clinical activity of TRAIL receptor targeting is not known. TRAIL-targeting therapeutics are highly specific for the TRAIL death receptors. Therefore, the level of receptor expression should be evaluated in clinical specimens as a prerequisite for patient's inclusion in clinical studies. Clinical translation of gene therapy approaches using adenovector-transduced cells for delivery of membrane-bound TRAIL represent a challenging strategy that might achieve systemic tumor targeting and increased intratumor delivery of the therapeutic agent.
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Footnotes
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Grant support: Ministero dell'Università e della Ricerca (MUR, Rome, Italy), Ministero della Salute (Rome, Italy), and Michelangelo Foundation for Advances in Cancer Research and Treatment (Milan, Italy).
Received 11/22/06;
revised 12/ 4/06;
accepted 12/14/06.
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References
|
|---|
- Laconi E, Pani P, Farber E. The resistance phenotype in the development and treatment of cancer. Lancet Oncol 2000;1:23541.[CrossRef][Medline]
- Pommier Y, Sordet O, Antony S, Hayward RL, Kohn KW. Apoptosis defects and chemotherapy resistance: molecular interaction maps and networks. Oncogene 2004;23:293449.[CrossRef][Medline]
- Waxman DJ, Schwartz PS. Harnessing apoptosis for improved anticancer gene therapy. Cancer Res 2003;63:856372.[Abstract/Free Full Text]
- Ashkenazi A. Targeting death and decoy receptors of the tumour-necrosis factor superfamily. Nat Rev Cancer 2002;2:42030.[CrossRef][Medline]
- Wajant H. Death receptors. Essays Biochem 2003;39:5371.[Medline]
- Wiley SR, Schooley K, Smolak PJ, et al. Identification and characterization of a new member of the TNF family that induces apoptosis. Immunity 1995;3:67382.[CrossRef][Medline]
- Almasan A, Ashkenazi A. Apo2L/TRAIL: apoptosis signaling, biology, and potential for cancer therapy. Cytokine Growth Factor Rev 2003;14:33748.[CrossRef][Medline]
- Mariani SM, Matiba B, Armandola EA, Krammer PH. Interleukin 1 ß-converting enzyme related proteases/caspases are involved in TRAIL-induced apoptosis of myeloma and leukemia cells. J Cell Biol 1997;137:2219.[Abstract/Free Full Text]
- Pitti RM, Marsters SA, Ruppert S, Donahue CJ, Moore A, Ashkenazi A. Induction of apoptosis by Apo-2 ligand, a new member of the tumor necrosis factor cytokine family. J Biol Chem 1996;271:1268790.[Abstract/Free Full Text]
- Ashkenazi A, Pai RC, Fong S, et al. Safety and antitumor activity of recombinant soluble Apo2 ligand. J Clin Invest 1999;104:15562.[Medline]
- Fulda S, Wick W, Weller M, Debatin K-M. Smac agonists sensitize for Apo2L/TRAIL- or anticancer drug-induced apoptosis and induce regression of malignant glioma in vivo. Nat Med 2002;8:80815.[Medline]
- LeBlanc H, Lawrence D, Varfolomeev E, et al. Tumor-cell resistance to death receptor-induced apoptosis through mutational inactivation of the proapoptotic Bcl-2 homolog Bax. Nat Med 2002;8:27481.[CrossRef][Medline]
- Mitsiades CS, Treon SP, Mitsiades N, et al. TRAIL/Apo2L ligand selectively induces apoptosis and overcomes drug resistance in multiple myeloma: therapeutic applications. Blood 2001;98:795804.[Abstract/Free Full Text]
- Pollack IF, Erff M, Ashkenazi A. Direct stimulation of apoptotic signaling by soluble Apo2L/tumor necrosis factorrelated apoptosis-inducing ligand leads to selective killing of glioma cells. Clin Cancer Res 2001;7:13629.[Abstract/Free Full Text]
- Walczak H, Miller RE, Ariail K, et al. Tumoricidal activity of tumor necrosis factorrelated apoptosis-inducing ligand in vivo. Nat Med 1999;5:15763.[CrossRef][Medline]
- Lawrence D, Shahrokh Z, Marsters S, et al. Differential hepatocyte toxicity of recombinant Apo2L/TRAIL versions. Nat Med 2001;7:3835.[CrossRef][Medline]
- Smyth MJ, Takeda K, Hayakawa Y, Peschon JJ, van den Brink MR, Yagita H. Nature's TRAIL-on a path to cancer immunotherapy. Immunity 2003;18:16.[CrossRef][Medline]
- Cretney E, Takeda K, Yagita H, Glaccum M, Peschon JJ, Smyth MJ. Increased susceptibility to tumor initiation and metastasis in TNF-related apoptosis-inducing ligand-deficient mice. J Immunol 2002;168:135661.[Abstract/Free Full Text]
- Lamhamedi-Cherradi SE, Zheng SJ, Maguschak KA, Peschon J, Chen YH. Defective thymocyte apoptosis and accelerated autoimmune diseases in TRAIL/ mice. Nat Immunol 2003;4:25560.[CrossRef][Medline]
- Pan G, O'Rourke K, Chinnaiyan AM, et al. The receptor for the cytotoxic ligand TRAIL. Science 1997;276:1113.[Abstract/Free Full Text]
- Walczak H, Degli-Esposti MA, Johnson RS, et al. TRAIL-R2: a novel apoptosis-mediating receptor for TRAIL. EMBO J 1997;16:538697.[CrossRef][Medline]
- Sheridan JP, Marsters SA, Pitti RM, et al. Control of TRAIL-induced apoptosis by a family of signaling and decoy receptors. Science 1997;277:81821.[Abstract/Free Full Text]
- Pan G, Ni J, Wei YF, Yu G, Gentz R, Dixit VM. An antagonist decoy receptor and a death domain-containing receptor for TRAIL. Science 1997;277:8158.[Abstract/Free Full Text]
- Degli-Esposti MA, Dougall WC, Smolak PJ, Waugh JY, Smith CA, Goodwin RG. The novel receptor TRAIL-R4 induces NF-
B and protects against TRAIL-mediated apoptosis, yet retains an incomplete death domain. Immunity 1997;7:81320.[CrossRef][Medline] - Emery JG, McDonnell P, Burke MB, et al. Osteoprotegerin is a receptor for the cytotoxic ligand TRAIL. J Biol Chem 1998;273:143637.[Abstract/Free Full Text]
- Wang S, El-Deiry WS. TRAIL and apoptosis induction by TNF-family death receptors. Oncogene 2003;22:862833.[CrossRef][Medline]
- Holen I, Croucher PI, Hamdy FC, Eaton CL. Osteoprotegerin (OPG) is a survival factor for human prostate cancer cells. Cancer Res 2002;62:161923.[Abstract/Free Full Text]
- Kaufmann SH, Steensma DP. On the TRAIL of a new therapy for leukemia. Leukemia 2005;19:2195202.[CrossRef][Medline]
- Scaffidi C, Fulda S, Srinivasan A, et al. Two CD95 (APO-1/Fas) signaling pathways. EMBO J 1998;17:167587.[CrossRef][Medline]
- Lucken-Ardjomande S, Martinou JC. Newcomers in the process of mitochondrial permeabilization. J Cell Sci 2005;118:47383.[Abstract/Free Full Text]
- Verhagen AM, Vaux DL. Cell death regulation by the mammalian IAP antagonist Diablo/Smac. Apoptosis 2002;7:1636.[CrossRef][Medline]
- Buchsbaum DJ, Zhou T, Lobuglio AF. TRAIL receptor-targeted therapy. Future Oncol 2006;2:493508.[CrossRef][Medline]
- Rowinsky EK. Targeted induction of apoptosis in cancer management: the emerging role of tumor necrosis factorrelated apoptosis-inducing ligand receptor activating agents. J Clin Oncol 2005;23:9394407.[Abstract/Free Full Text]
- Zhang L, Fang B. Mechanisms of resistance to TRAIL-induced apoptosis in cancer. Cancer Gene Ther 2005;12:22837.[CrossRef][Medline]
- Hasegawa H, Yamada Y, Harasawa H, et al. Sensitivity of adult T-cell leukaemia lymphoma cells to tumour necrosis factor-related apoptosis-inducing ligand. Br J Haematol 2005;128:25365.[CrossRef][Medline]
- Johnston JB, Kabore AF, Strutinsky J, et al. Role of the TRAIL/APO2-L death receptors in chlorambucil- and fludarabine-induced apoptosis in chronic lymphocytic leukemia. Oncogene 2003;22:835669.[CrossRef][Medline]
- Mathas S, Lietz A, Anagnostopoulos I, et al. c-FLIP mediates resistance of Hodgkin/Reed-Sternberg cells to death receptor-induced apoptosis. J Exp Med 2004;199:104152.[Abstract/Free Full Text]
- Mouzakiti A, Packham G. Regulation of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in Burkitt's lymphoma cell lines. Br J Haematol 2003;122:619.[CrossRef][Medline]
- Hao C, Song JH, Hsi B, et al. TRAIL inhibits tumor growth but is nontoxic to human hepatocytes in chimeric mice. Cancer Res 2004;64:85026.[Abstract/Free Full Text]
- LeBlanc HN, Ashkenazi A. Apo2L/TRAIL and its death and decoy receptors. Cell Death Differ 2003;10:6675.[CrossRef][Medline]
- Wen J, Ramadevi N, Nguyen D, Perkins C, Worthington E, Bhalla K. Antileukemic drugs increase death receptor 5 levels and enhance Apo-2L-induced apoptosis of human acute leukemia cells. Blood 2000;96:39006.
- Chinnaiyan AM, Prasad U, Shankar S, et al. Combined effect of tumor necrosis factorrelated apoptosis-inducing ligand and ionizing radiation in breast cancer therapy. Proc Natl Acad Sci U S A 2000;97:17549.[Abstract/Free Full Text]
- Johnson TR, Stone K, Nikrad M, et al. The proteasome inhibitor PS-341 overcomes TRAIL resistance in Bax and caspase 9-negative or Bcl-xL overexpressing cells. Oncogene 2003;22:495363.[CrossRef][Medline]
- Nakata S, Yoshida T, Horinaka M, Shiraishi T, Wakada M, Sakai T. Histone deacetylase inhibitors upregulate death receptor 5/TRAIL-R2 and sensitize apoptosis induced by TRAIL/APO2-L in human malignant tumor cells. Oncogene 2004;23:626171.[CrossRef][Medline]
- Lee J, Hampl M, Albert P, Fine HA. Antitumor activity and prolonged expression from a TRAIL-expressing adenoviral vector. Neoplasia 2002;4:31223.[CrossRef][Medline]
- Armeanu S, Lauer UM, Smirnow I, et al. Adenoviral gene transfer of tumor necrosis factorrelated apoptosis-inducing ligand overcomes an impaired response of hepatoma cells but causes severe apoptosis in primary human hepatocytes. Cancer Res 2003;63:236972.[Abstract/Free Full Text]
- Griffith TS, Anderson RD, Davidson BL, Williams RD, Ratliff TL. Adenoviral-mediated transfer of the TNF-related apoptosis-inducing ligand/Apo-2 ligand gene induces tumor cell apoptosis. J Immunol 2000;165:288694.[Abstract/Free Full Text]
- Griffith TS, Broghammer EL. Suppression of tumor growth following intralesional therapy with TRAIL recombinant adenovirus. Mol Ther 2001;4:25766.[CrossRef][Medline]
- Kagawa S, He C, Gu J, et al. Antitumor activity and bystander effects of the tumor necrosis factorrelated apoptosis-inducing ligand (TRAIL) gene. Cancer Res 2001;61:33308.[Abstract/Free Full Text]
- Harrington K, Alvarez-Vallina L, Crittenden M, et al. Cells as vehicles for cancer gene therapy: the missing link between targeted vectors and systemic delivery? Hum Gene Ther 2002;13:126380.[CrossRef][Medline]
- Carlo-Stella C, Lavazza C, Nicola MD, et al. Antitumor activity of human CD34(+) cells expressing membrane-bound tumor necrosis factorrelated apoptosis-inducing ligand. Hum Gene Ther 2006;17:122540.[CrossRef][Medline]
- Burger JA, Kipps TJ. CXCR4: a key receptor in the crosstalk between tumor cells and their microenvironment. Blood 2006;107:17617.[Abstract/Free Full Text]
- Verfaillie CM. Adhesion receptors as regulators of the hematopoietic process. Blood 1998;92:260912.[Free Full Text]
- Kaplan RN, Riba RD, Zacharoulis S, et al. VEGFR1-positive haematopoietic bone marrow progenitors initiate the pre-metastatic niche. Nature 2005;438:8207.[CrossRef][Medline]
- Jin H, Aiyer A, Su J, et al. A homing mechanism for bone marrow-derived progenitor cell recruitment to the neovasculature. J Clin Invest 2006;116:65262.[CrossRef][Medline]
- Muhlenbeck F, Schneider P, Bodmer JL, et al. The tumor necrosis factorrelated apoptosis-inducing ligand receptors TRAIL-R1 and TRAIL-R2 have distinct cross-linking requirements for initiation of apoptosis and are non-redundant in JNK activation. J Biol Chem 2000;275:3220813.[Abstract/Free Full Text]
- Wajant H, Moosmayer D, Wuest T, et al. Differential activation of TRAIL-R1 and -2 by soluble and membrane TRAIL allows selective surface antigen-directed activation of TRAIL-R2 by a soluble TRAIL derivative. Oncogene 2001;20:41016.[CrossRef][Medline]