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van der Luit AH, Vink SR, Klarenbeek JB, Perrissoud D, Solary E, Verheij M, van Blitterswijk WJ. A new class of anticancer alkylphospholipids uses lipid rafts as membrane gateways to induce apoptosis in lymphoma cells. Mol Cancer Ther 2007; 6:2337-45. [PMID: 17699729 DOI: 10.1158/1535-7163.mct-07-0202] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Single-chain alkylphospholipids, unlike conventional chemotherapeutic drugs, act on cell membranes to induce apoptosis in tumor cells. We tested four different alkylphospholipids, i.e., edelfosine, perifosine, erucylphosphocholine, and compound D-21805, as inducers of apoptosis in the mouse lymphoma cell line S49. We compared their mechanism of cellular entry and their potency to induce apoptosis through inhibition of de novo biosynthesis of phosphatidylcholine at the endoplasmic reticulum. Alkylphospholipid potency closely correlated with the degree of phosphatidylcholine synthesis inhibition in the order edelfosine > D-21805 > erucylphosphocholine > perifosine. In all cases, exogenous lysophosphatidylcholine, an alternative source for cellular phosphatidylcholine production, could partly rescue cells from alkylphospholipid-induced apoptosis, suggesting that phosphatidylcholine biosynthesis is a direct target for apoptosis induction. Cellular uptake of each alkylphospholipid was dependent on lipid rafts because pretreatment of cells with the raft-disrupting agents, methyl-beta-cyclodextrin, filipin, or bacterial sphingomyelinase, reduced alkylphospholipid uptake and/or apoptosis induction and alleviated the inhibition of phosphatidylcholine synthesis. Uptake of all alkylphospholipids was inhibited by small interfering RNA (siRNA)-mediated blockage of sphingomyelin synthase (SMS1), which was previously shown to block raft-dependent endocytosis. Similar to edelfosine, perifosine accumulated in (isolated) lipid rafts independent on raft sphingomyelin content per se. However, perifosine was more susceptible than edelfosine to back-extraction by fatty acid-free serum albumin, suggesting a more peripheral location in the cell due to less effective internalization. Overall, our results suggest that lipid rafts are critical membrane portals for cellular entry of alkylphospholipids depending on SMS1 activity and, therefore, are potential targets for alkylphospholipid anticancer therapy.
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Affiliation(s)
- Arnold H van der Luit
- Division of Cellular Biochemistry, the Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
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Vinall RL, Hwa K, Ghosh P, Pan CX, Lara PN, de Vere White RW. Combination treatment of prostate cancer cell lines with bioactive soy isoflavones and perifosine causes increased growth arrest and/or apoptosis. Clin Cancer Res 2007; 13:6204-16. [PMID: 17947488 DOI: 10.1158/1078-0432.ccr-07-0600] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To determine whether targeting the androgen receptor (AR) and Akt pathways using a combination of genistein combined polysaccharide (GCP) and perifosine is more effective at inducing growth arrest/apoptosis in prostate cancer cells compared with treatment with GCP or perifosine as single agents. EXPERIMENTAL DESIGN The effect of GCP and perifosine treatment was assessed in five prostate cancer cell lines: LNCaP (androgen sensitive), LNCaP-R273H, C4-2, Cds1, and PC3 (androgen insensitive). A clonogenic assay assessed the long-term effects on cell growth and survival. Flow cytometry and Western blot analysis of poly(ADP)ribose polymerase cleavage were used to assess short-term effects. Preliminary studies to investigate mechanism of action included Western blot for P-Akt, Akt, P-p70S6K, p70S6K, p53, and p21; prostate-specific antigen analysis; and the use of myristoylated Akt and AR-specific small interfering RNA. RESULTS Combination treatment with GCP and perifosine caused a decrease in clonogenic potential in all cell lines. In short-term assays, growth arrest was observed in the majority of cell lines, as well as increased inhibition of Akt activity and induction of p21 expression. Increased apoptosis was only observed in LNCaP. Knockdown of AR caused a further increase in apoptosis. CONCLUSION Combination treatment with GCP and perifosine targets the Akt pathway in the majority of the prostate cancer cell lines and causes increased inhibition of cell growth and clonogenicity. In LNCaP, combination treatment targets both the Akt and AR pathways and causes increased apoptosis. These data warrant clinical validation in prostate cancer patients.
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Affiliation(s)
- Ruth L Vinall
- Department of Urology, University of California, Davis, School of Medicine and Cancer Center, Sacramento, California 95817, USA
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Proapoptotic activity and chemosensitizing effect of the novel Akt inhibitor perifosine in acute myelogenous leukemia cells. Leukemia 2007; 22:147-60. [PMID: 17928881 DOI: 10.1038/sj.leu.2404980] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The serine/threonine kinase Akt, a downstream effector of phosphatidylinositol 3-kinase (PI3K), is known to play an important role in antiapoptotic signaling and has been implicated in the aggressiveness of a number of different human cancers including acute myelogenous leukemia (AML). We have investigated the therapeutic potential of the novel Akt inhibitor, perifosine, on human AML cells. Perifosine is a synthetic alkylphospholipid, a new class of antitumor agents, which target plasma membrane and inhibit signal transduction networks. Perifosine was tested on THP-1 and MV 4-11 cell lines, as well as primary leukemia cells. Perifosine treatment induced cell death by apoptosis in AML cell lines. Perifosine caused Akt and ERK 1/2 dephosphorylation as well as caspase activation. In THP-1 cells, the proapoptotic effect of perifosine was partly dependent on the Fas/FasL system and c-jun-N-kinase activation. In MV 4-11 cells, perifosine downregulated phosphorylated Akt, but not phosphorylated FLT3. Moreover, perifosine reduced the clonogenic activity of AML, but not normal, CD34(+) cells, and markedly increased blast cell sensitivity to etoposide. Our findings indicate that perifosine, either alone or in combination with existing drugs, might be a promising therapeutic agent for the treatment of those AML cases characterized by upregulation of the PI3K-Akt survival pathway.
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Erufosine, a novel alkylphosphocholine, in acute myeloid leukemia: single activity and combination with other antileukemic drugs. Cancer Chemother Pharmacol 2007; 62:321-9. [PMID: 17922125 PMCID: PMC2755757 DOI: 10.1007/s00280-007-0612-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 09/17/2007] [Indexed: 10/27/2022]
Abstract
PURPOSE Alkylphosphocholines represent a new class of cytostatic drugs with a novel mode of action. Erufosine (ErPC3), the first compound of this class that can be administered intravenously, has recently been shown to be active against human tumor and leukemic cell lines. METHODS In order to evaluate the antileukemic potential of ErPC3 in acute myeloid leukemia (AML) the lethal concentration 50% (LC 50) was determined using WST-1 assay. For analysis of cell death, staining for Annexin V and activated caspase 3 was performed. An interaction analysis was performed by calculation of combination index and construction of isobolograms. RESULTS The LC 50 was 7.4 microg/ml after 24 h and 3.2 microg/ml after 72 h in HL 60 cells and 30.1 and 8.6 microg/ml, respectively, in 19 fresh samples from patients with AML. ErPC3 was found to be cytotoxic in HL60 cells with distinct activation of caspase 3. ErPC3 was not cross-resistant with cytarabine, idarubicine and etoposide as shown by the linear relation of respective LC 50s. The latter agents, however, exerted an additive cytotoxicity in combination with ErPC3 as revealed by isobologram analysis and combination index, although results are uneven for idarubicine. CONCLUSION Based on these data ErPC3 appears as a novel antileukemic candidate drug, which needs to be explored further in the treatment of AML.
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Abstract
BACKGROUND Malignant stem cells have been identified in acute myelogenous leukemia, chronic myeloid leukemia, and some types of acute lymphoblastic leukemia. Like normal stem cells, these leukemic stem cells (LSCs) are able to self-renew, differentiate, and proliferate extensively. Evidence suggests that LSCs are critical for the initiation and perpetuation of leukemic disease. METHODS We reviewed the literature describing the characteristic features of LSCs in various leukemias and the novel molecular approaches being used to specifically ablate the LSC population. RESULTS Studies have demonstrated the potential importance of ablating LSCs when treating leukemia. The unique characteristics of LSCs that differentiate them from their normal counterparts can be exploited to specifically target the malignant population. CONCLUSIONS Current therapeutic strategies may not effectively ablate the LSC, leaving the potential for disease progression or relapse. A better understanding of LSC cell and molecular biology will allow the design of more effective therapies.
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MESH Headings
- Antibodies, Monoclonal/therapeutic use
- Antineoplastic Agents/therapeutic use
- Drug Evaluation
- Enzyme Inhibitors/therapeutic use
- Humans
- Leukemia/drug therapy
- Leukemia/pathology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy
- Leukemia, Myeloid, Acute/pathology
- Leukemia, Myeloid, Acute/therapy
- Neoplastic Stem Cells/drug effects
- Neoplastic Stem Cells/pathology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy
- Treatment Outcome
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Affiliation(s)
- Monica L Guzman
- Blood and Marrow Transplant Program, Markey Cancer Center, Division of Hematology/Oncology, University of Kentucky Medical Center, Lexington, Kentucky, USA
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107
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Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis. BMC Cell Biol 2007; 8:15. [PMID: 17509155 PMCID: PMC1888687 DOI: 10.1186/1471-2121-8-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Accepted: 05/17/2007] [Indexed: 11/23/2022] Open
Abstract
Background Phosphatidylinositol 4,5-bisphosphate (PIP2) is required for successful completion of cytokinesis. In addition, both PIP2 and phosphoinositide-specific phospholipase C (PLC) have been localized to the cleavage furrow of dividing mammalian cells. PLC hydrolyzes PIP2 to yield diacylglycerol (DAG) and inositol trisphosphate (IP3), which in turn induces calcium (Ca2+) release from the ER. Several studies suggest PIP2 must be hydrolyzed continuously for continued cleavage furrow ingression. The majority of these studies employ the N-substituted maleimide U73122 as an inhibitor of PLC. However, the specificity of U73122 is unclear, as its active group closely resembles the non-specific alkylating agent N-ethylmaleimide (NEM). In addition, the pathway by which PIP2 regulates cytokinesis remains to be elucidated. Results Here we compared the effects of U73122 and the structurally unrelated PLC inhibitor ET-18-OCH3 (edelfosine) on cytokinesis in crane-fly and Drosophila spermatocytes. Our data show that the effects of U73122 are indeed via PLC because U73122 and ET-18-OCH3 produced similar effects on cell morphology and actin cytoskeleton organization that were distinct from those caused by NEM. Furthermore, treatment with the myosin light chain kinase (MLCK) inhibitor ML-7 caused cleavage furrow regression and loss of both F-actin and phosphorylated myosin regulatory light chain from the contractile ring in a manner similar to treatment with U73122 and ET-18-OCH3. Conclusion We have used multiple inhibitors to examine the roles of PLC and MLCK, a predicted downstream target of PLC regulation, in cytokinesis. Our results are consistent with a model in which PIP2 hydrolysis acts via Ca2+ to activate myosin via MLCK and thereby control actin dynamics during constriction of the contractile ring.
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Putz T, Ramoner R, Gander H, Rahm A, Bartsch G, Bernardo K, Ramsay S, Thurnher M. Bee venom secretory phospholipase A2 and phosphatidylinositol-homologues cooperatively disrupt membrane integrity, abrogate signal transduction and inhibit proliferation of renal cancer cells. Cancer Immunol Immunother 2007; 56:627-40. [PMID: 16947021 PMCID: PMC11030745 DOI: 10.1007/s00262-006-0220-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Accepted: 08/02/2006] [Indexed: 02/02/2023]
Abstract
Bee venom secretory phospholipase A2 (bv-sPLA2) and phosphatidylinositol-(3,4)-bisphosphate (PtdIns(3,4)P2) act synergistically to induce cell death in tumour cells of various origins with concomitant stimulation of the immune system. Here, we investigated the mechanisms involved in such actions and examined structural requirements of PtdIns-homologues to inhibit tumour cells in combination with bv-sPLA2. Renal cancer cells were treated with bv-sPLA2 alone or in combination with PtdIns-homologues. Inhibitory effects on [(3)H] thymidine incorporation and intracellular signal transduction pathways were tested. Reaction products generated by bv-sPLA2 interaction with PtdIns(3,4)P2 were identified by mass spectrometry. Among the tested PtdIns-homologues those with a phosphate esterified to position 3 of the inositol head group, were most efficient in cooperating with bv-sPLA2 to block tumour cell proliferation. Growth inhibition induced by the combined action of bv-sPLA2 with either PtdIns(3,4)bisphosphate or PtdIns(3,4,5)trisphosphate were synergistic and accompanied by potent cell lysis. In contrast, PtdIns, which lacked the phosphate group at position 3, failed to promote synergistic growth inhibition. The combined administration of PtdIns(3,4)P2 and bv-sPLA2 abrogated signal transduction mediated by extracellular signal regulated kinase 1 and 2 and prevented transduction of survival signals mediated by protein kinase B. Surface expression of the epidermal growth factor (EGF)-receptor was reduced after PtdIns(3,4)P2-bv-sPLA2 administration and associated with a blockade of EGF-induced signalling. In addition, mass spectroscopy revealed that bv-sPLA2 cleaves PtdIns(3,4)P2 to generate lyso-PtdIns(3,4)P2. In conclusion, we suggest that the cytotoxic activity mediated by PtdIns(3,4)P2 and bv-sPLA2 is due to cell death that results from disruption of membrane integrity, abrogation of signal transduction and the generation of cytotoxic lyso-PtdIns(3,4)P2.
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Affiliation(s)
- Thomas Putz
- Department of Urology and kompetenzzentrum medizin tirol, Innsbruck Medical University, Innsbruck, Austria.
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Leighl NB, Dent S, Clemons M, Vandenberg TA, Tozer R, Warr DG, Crump RM, Hedley D, Pond GR, Dancey JE, Moore MJ. A Phase 2 study of perifosine in advanced or metastatic breast cancer. Breast Cancer Res Treat 2007; 108:87-92. [PMID: 17458693 DOI: 10.1007/s10549-007-9584-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 03/26/2007] [Indexed: 11/29/2022]
Abstract
BACKGROUND First- and second-line chemotherapy with anthracyclines and taxanes in metastatic breast cancer yield a modest improvement in survival with potentially significant toxicity. Subsequent lines of chemotherapy yield response rates of 20-25%, with an unknown impact on survival. Perifosine, an oral alkylphospholipid structurally related to miltefosine, has marked activity against breast cancer cell lines and xenograft models, with broad spectrum cellular effects. OBJECTIVES To determine the efficacy and toxicity of perifosine in patients with metastatic breast cancer patients after up to 2 lines of prior chemotherapy for advanced disease. METHODS 18 patients were enrolled, and 17 treated, using a loading/maintenance dose schedule, (day 1, 300 mg, maintenance 150 mg days 2-21) every 28 days, until disease progression or unacceptable toxicity. RESULTS Median age of patients was 54 (28-69), 16/17 were female, ECOG performance status was 0/1 in 16 patients. Fifteen received at least 1 prior chemotherapy regimen for metastatic disease (maximum 2). A median of 2 cycles (range 1-13) was administered per patient. Sixteen were evaluable for response: 2 had SD for 4 cycles, 1 SD for 13 cycles, 13 progressed by cycle 2. Grade 3/4 drug-related non-hematologic toxicities include: diarrhea (2), vomiting (2), nausea (2), fatigue (2) and anorexia (1). No grade 3/4 hematologic toxicities were seen. Median time to progression was 8 weeks (7-15 weeks). CONCLUSION No objective responses were seen in this group of pretreated metastatic breast cancer patients. Disease stabilization was observed in 19% at 2 months.
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Affiliation(s)
- Natasha B Leighl
- Medical Oncology, Princess Margaret Hospital/University Health Network, Toronto, ON, Canada.
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110
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Mollinedo F. Antitumour ether lipids: proapoptotic agents with multiple therapeutic indications. Expert Opin Ther Pat 2007. [DOI: 10.1517/13543776.17.4.385] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Paris C, Bertoglio J, Bréard J. Lysosomal and mitochondrial pathways in miltefosine-induced apoptosis in U937 cells. Apoptosis 2007; 12:1257-67. [PMID: 17347868 DOI: 10.1007/s10495-007-0052-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Hexadecylphosphocholine (HePC) is an anticancer agent whose effect has been shown to involve apoptosis induction but the signaling pathways leading to apoptosis remain to be elucidated. We show here that HePC induces activation of caspase-9, -3, and -8 via the intrinsic pathway, release of cytochrome c, activation and relocation of Bax to the mitochondria as well as the cleavage of Bid. Moreover, a lysosomal pathway characterized by partial lysosomal rupture, cathepsin B activation and relocation from lysosomes to the cytosol, is involved in HePC-induced apoptosis. A cathepsin B/L inhibitor partially suppresses caspase activation and apoptosis induction, indicating signaling between lysosomes and mitochondria. Conversely, the pancaspase inhibitor Q-VD-OPH inhibits lysosomal rupture, but only at early time points, suggesting that immediate lysosomal rupture involves caspases. Overexpression of Bcl-2, an anti-apoptotic protein known to prevent mitochondrial dysfunction, totally abrogates lysosomal destabilization and cell death.
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Affiliation(s)
- Caroline Paris
- INSERM U749, Faculté de Pharmacie Paris-Sud. 5, rue Jean-Baptiste Clément 92290, Châtenay-Malabry, France
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Rationale and clinical application of alkylphospholipid analogues in combination with radiotherapy. Cancer Treat Rev 2007; 33:191-202. [PMID: 17287087 DOI: 10.1016/j.ctrv.2006.12.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/01/2006] [Accepted: 12/04/2006] [Indexed: 12/29/2022]
Abstract
Concurrent treatment with radiotherapy and chemotherapy has emerged as an effective strategy to improve clinical outcome of cancer. In addition to combining radiation with classical anticancer agents, several new biological response modifiers are under investigation in pre-clinical and clinical studies. Synthetic alkylphospholipids are anticancer agents that in contrast to most anticancer drugs, do not target DNA, but insert in the plasma membrane and subsequently induce a broad range of biological effects, ultimately leading to cell death. Alkylphospholipids kill tumor cells directly by induction of both apoptotic and non-apoptotic cell death, and indirectly by interference with critical signal transduction pathways involved in phospholipid metabolism and survival. Due to their distinct mode of action, these drugs are considered as attractive candidates to combine with radiotherapy. In this review, we will discuss several alkylphospholipids that reached clinical application. These include first-generation alkyl-lysophospholipids edelfosine and ilmofosine, second-generation alkylphosphocholine-prototype miltefosine and more recently developed analogues perifosine and erucylphosphocholine. We focus on mechanisms of action and the rationale to combine these agents with radiotherapy. The preclinical results on molecular targeting underlying this approach will be reviewed, concluded with first clinical data on combined treatment of radiotherapy with perifosine.
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Van der Luit A, Budde M, Zerp S, Caan W, Klarenbeek J, Verheij M, van Blitterswijk W. Resistance to alkyl-lysophospholipid-induced apoptosis due to downregulated sphingomyelin synthase 1 expression with consequent sphingomyelin- and cholesterol-deficiency in lipid rafts. Biochem J 2007; 401:541-9. [PMID: 17049047 PMCID: PMC1820802 DOI: 10.1042/bj20061178] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ALP (alkyl-lysophospholipid) edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine; Et-18-OCH3) induces apoptosis in S49 mouse lymphoma cells. To this end, ALP is internalized by lipid raft-dependent endocytosis and inhibits phosphatidylcholine synthesis. A variant cell-line, S49AR, which is resistant to ALP, was shown previously to be unable to internalize ALP via this lipid raft pathway. The reason for this uptake failure is not understood. In the present study, we show that S49AR cells are unable to synthesize SM (sphingomyelin) due to down-regulated SMS1 (SM synthase 1) expression. In parental S49 cells, resistance to ALP could be mimicked by small interfering RNA-induced SMS1 suppression, resulting in SM deficiency and blockage of raft-dependent internalization of ALP and induction of apoptosis. Similar results were obtained by treatment of the cells with myriocin/ISP-1, an inhibitor of general sphingolipid synthesis, or with U18666A, a cholesterol homoeostasis perturbing agent. U18666A is known to inhibit Niemann-Pick C1 protein-dependent vesicular transport of cholesterol from endosomal compartments to the trans-Golgi network and the plasma membrane. U18666A reduced cholesterol partitioning in detergent-resistant lipid rafts and inhibited SM synthesis in S49 cells, causing ALP resistance similar to that observed in S49AR cells. The results are explained by the strong physical interaction between (newly synthesized) SM and available cholesterol at the Golgi, where they facilitate lipid raft formation. We propose that ALP internalization by lipid-raft-dependent endocytosis represents the retrograde route of a constitutive SMS1- and lipid-raft-dependent membrane vesicular recycling process.
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Affiliation(s)
- Arnold H. Van der Luit
- *Division of Cellular Biochemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Marianne Budde
- *Division of Cellular Biochemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Shuraila Zerp
- †Department of Radiotherapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Wendy Caan
- *Division of Cellular Biochemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Jeffrey B. Klarenbeek
- *Division of Cellular Biochemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Marcel Verheij
- †Department of Radiotherapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Wim J. van Blitterswijk
- *Division of Cellular Biochemistry, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
- To whom correspondence should be addressed (email )
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Chapter 23 Small Molecule Inhibitors of AKT/PKB Kinase as a Strategy for Treating Cancer. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2007. [DOI: 10.1016/s0065-7743(07)42023-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Khundmiri SJ, Metzler MA, Ameen M, Amin V, Rane MJ, Delamere NA. Ouabain induces cell proliferation through calcium-dependent phosphorylation of Akt (protein kinase B) in opossum kidney proximal tubule cells. Am J Physiol Cell Physiol 2006; 291:C1247-57. [PMID: 16807298 DOI: 10.1152/ajpcell.00593.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiotonic glycosides, like ouabain, inhibit Na+-K+-ATPase. Recent evidence suggests that low molar concentrations of ouabain alter cell growth. Studies were conducted to examine the effect of ouabain on Akt phosphorylation and rate of cell proliferation in opossum kidney (OK) proximal tubule cells. Cells exposed to 10 nM ouabain displayed increased Akt Ser473phosphorylation, as evidenced by an increase in phospho-Akt Ser473band density. Ouabain-stimulated Akt Ser473phosphorylation was inhibited by pretreatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 and wortmannin), a PLC inhibitor (edelfosine), and an Akt inhibitor. Moreover, ouabain-mediated Akt Ser473phosphorylation was suppressed by reduction of extracellular calcium (EGTA) or when intracellular calcium was buffered by BAPTA-AM. An inhibitor of calcium store release (TMB-8) and an inhibitor of calcium entry via store-operated calcium channels ( SKF96365 ) also suppressed ouabain-mediated Akt Ser473phosphorylation. In fura-2 AM-loaded cells, 10 nM ouabain increased capacitative calcium entry (CCE). Ouabain at 10 nM did not significantly alter baseline cytoplasmic calcium concentration in control cells. However, treatment with 10 nM ouabain caused a significantly higher ATP-mediated calcium store release. After 24 h, 10 nM ouabain increased the rate of cell proliferation. The Akt inhibitor, BAPTA-AM, SKF96365 , and cyclopiazonic acid suppressed the increase in the rate of cell proliferation caused by 10 nM ouabain. Ouabain at 10 nM caused a detectable increase in86Rb uptake but did not significantly alter Na+-K+-ATPase (ouabain-sensitive pNPPase) activity in crude membranes or cell sodium content. Taken together, the results point to a role for CCE and Akt phosphorylation, in response to low concentrations of ouabain, that increase the rate of cell proliferation without inhibiting Na+-K+-ATPase-mediated ion transport.
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Affiliation(s)
- Syed J Khundmiri
- Department of Medicine, University of Louisville, Louisville, Kentucky 40202, USA.
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Khasawneh MK, Bukowski RM. Pathways of Dysregulation in Renal Cell Carcinoma: Rational Approaches to Development of Novel Treatment. Clin Genitourin Cancer 2006; 5 Suppl 1:S7-S18. [PMID: 17239285 DOI: 10.3816/cgc.2006.s.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Recent developments have involved a series of novel agents that produce clinical benefit in patients with advanced clear-cell renal cell carcinoma (RCC). The molecular characteristics of RCC, pathways involved in growth and progression, and development of targeted therapeutic approaches have become the focus of many investigators in the past decade. A variety of genetic abnormalities, molecular markers and drugs that target these markers or alter the genetic expression of certain regulatory proteins, have been identified and might have clinical significance for prognosis and treatment. However, specific markers associated with RCC and further development of novel single or combination targeted therapies is now required. An understanding of the complicated and unique biologic behavior of RCC and its various histologic subtypes is crucial for the continued development of novel and targeted therapies.
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de la Peña L, Burgan WE, Carter DJ, Hollingshead MG, Satyamitra M, Camphausen K, Tofilon PJ. Inhibition of Akt by the alkylphospholipid perifosine does not enhance the radiosensitivity of human glioma cells. Mol Cancer Ther 2006; 5:1504-10. [PMID: 16818509 DOI: 10.1158/1535-7163.mct-06-0091] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Akt has been implicated as a molecular determinant of cellular radiosensitivity. Because it is often constitutively activated or overexpressed in malignant gliomas, it has been suggested as a target for brain tumor radiosensitization. To evaluate the role of Akt in glioma radioresponse, we have determined the effects of perifosine, a clinically relevant alkylphospholipid that inhibits Akt activation, on the radiosensitivity of three human glioma cell lines (U87, U251, and LN229). Each of the glioma cell lines expressed clearly detectable levels of phosphorylated Akt indicative of constitutive Akt activity. Exposure to a perifosine concentration that reduced survival by approximately 50% significantly reduced the level of phosphorylated Akt as well as Akt activity. Cell survival analysis using a clonogenic assay, however, revealed that this Akt-inhibiting perifosine treatment did not enhance the radiosensitivity of the glioma cell lines. This evaluation was then extended to an in vivo model using U251 xenografts. Perifosine delivered to mice bearing U251 xenografts substantially reduced tumor phosphorylated Akt levels and inhibited tumor growth rate. However, the combination of perifosine and radiation resulted in a less than additive increase in tumor growth delay. Thus, in vitro and in vivo data indicate that the perifosine-mediated decrease in Akt activity does not enhance the radiosensitivity of three genetically disparate glioma cell lines. These results suggest that, although Akt may influence the radiosensitivity of other tumor types, it does not seem to be a target for glioma cell radiosensitization.
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Affiliation(s)
- Lorena de la Peña
- Molecular Radiation Therapeutics Branch, National Cancer Institute, Bethesda, MD, USA
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118
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Nyåkern M, Cappellini A, Mantovani I, Martelli AM. Synergistic induction of apoptosis in human leukemia T cells by the Akt inhibitor perifosine and etoposide through activation of intrinsic and Fas-mediated extrinsic cell death pathways. Mol Cancer Ther 2006; 5:1559-70. [PMID: 16818515 DOI: 10.1158/1535-7163.mct-06-0076] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Perifosine is an Akt inhibitor displaying strong antineoplastic effects in human tumor cell lines and is currently being tested in phase II clinical trials for treatment of major human cancers. Several recent studies showed the apoptotic effect of perifosine alone or in combination with other anticancer agents. However, this is the first study describing the effects of combining perifosine with the commonly used chemotherapy drug etoposide in cultured human Jurkat T-leukemia cells. Low concentrations of perifosine (5 micromol/L) induced cell death in a synergistic fashion with etoposide if used simultaneously or immediately following exposure to etoposide (posttreatment). The increase in cell death seems to be due to an inactivation of the Akt survival pathway, where treated cells showed a complete dephosphorylation of Akt. Moreover, combined drug-induced Akt deactivation was associated with a parallel decrease in phosphorylation of FoxO1 transcription factor and in expression of antiapoptotic Bcl-xL. Furthermore, the increase in cell death was associated with a specific activation of the caspase-dependent Fas death receptor pathway. These findings might be useful when designing clinical trials where chemotherapy is combined with perifosine for a potential broad use against hematologic malignancies in which the Akt survival pathway is frequently activated.
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Affiliation(s)
- Maria Nyåkern
- Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Università di Bologna, via Irnerio 48, 40126 Bologna, Italy
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119
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Knowling M, Blackstein M, Tozer R, Bramwell V, Dancey J, Dore N, Matthews S, Eisenhauer E. A phase II study of perifosine (D-21226) in patients with previously untreated metastatic or locally advanced soft tissue sarcoma: A National Cancer Institute of Canada Clinical Trials Group trial. Invest New Drugs 2006; 24:435-9. [PMID: 16528479 DOI: 10.1007/s10637-006-6406-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
UNLABELLED BACKGROUND/PATIENTS AND METHODS: 16 adult patients with untreated measurable locally advanced or metastatic inoperable soft tissue sarcoma were treated with oral perifosine, a synthetic alkylphospholipid, believed to inhibit MAP kinase (MAP-K), protein kinase C (PKC), Akt and other regulatory proteins. Perifosine was administered orally in cycles for 21 days out of 28. Loading doses were given day 1 each cycle (900 mg cycle 1, 300 mg cycle 2+) and 150 mg daily was given days 2-21 of each cycle. Cycles were repeated until disease progression, unacceptable toxicity or patient refusal. RESULTS Seventeen patients were enrolled; 16 and 15 were evaluable for toxicity and response, respectively. A total of 30 cycles of perifosine were administered. Most toxic effects were grade 1 or 2 and commonly included nausea, vomiting, diarrhea, and fatigue (> or =40%). Hematologic toxicity was generally mild. There were no significant biochemical abnormalities due to the drug reported. There were 4 serious adverse events (SAE)-none of which was related to perifosine. No objective responses were seen; 4 patients had stable disease for 1.3 to 8.2 months and the remainder of the patients had progressive disease. CONCLUSIONS Perifosine when given according to this dosing schedule does not show evidence of activity in a mixed population of adult soft tissue sarcoma patients.
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Affiliation(s)
- M Knowling
- British Columbia Cancer Agency, 600 West 10th Avenue, Vancouver, BC, V5Z 4E6.
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120
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Vink SR, Schellens JHM, Beijnen JH, Sindermann H, Engel J, Dubbelman R, Moppi G, Hillebrand MJX, Bartelink H, Verheij M. Phase I and pharmacokinetic study of combined treatment with perifosine and radiation in patients with advanced solid tumours. Radiother Oncol 2006; 80:207-13. [PMID: 16914220 DOI: 10.1016/j.radonc.2006.07.032] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 07/20/2006] [Accepted: 07/21/2006] [Indexed: 12/21/2022]
Abstract
PURPOSE Perifosine is an orally applicable, membrane-targeted alkylphosphocholine analogue with antitumour activity and radiosensitising properties in preclinical models. The purpose of this phase I study was to determine the feasibility and tolerability of concurrent daily perifosine and radiation in patients with advanced cancer. PATIENTS AND METHODS Starting dose of perifosine was 50 mg/day; dose escalation was in steps of 50mg. Daily administration commenced 2 days before radiotherapy and was continued throughout the radiation treatment. At least three patients were entered at each dose level; at the 150 mg/day level 10 patients were included. Pharmacokinetic sampling was performed weekly pre-dosing. Twenty-one patients were entered. Tumour types included NSCLC (n=17), prostate, oesophageal, colon and bladder cancer. Most patients (16/21) had received prior chemotherapy; none radiotherapy. Median number of daily perifosine administrations was 31 (range 24-53). Mean radiation dose (BED(10)) was 59.8 Gy (range 50.7-87.5 Gy in 13-28 fractions). RESULTS Major drug-related toxicities according to CTC criteria were nausea in 57%, fatigue in 48%, vomiting in 38%, diarrhoea in 38% and anorexia in 19%. No bone marrow toxicity was observed. DLT (nausea/vomiting) was encountered in two of five patients at the 200mg/day dose level. Dose-dependent steady-state plasma levels were reached after 1 week. Major radiotherapy-related acute toxicity consisted of dysphagia in 38% and pneumonitis in 29%. CONCLUSION Perifosine can be safely combined with fractionated radiotherapy. A dosage of 150 mg/day, to be started at least 1 week prior to radiotherapy, is recommended for phase II evaluation.
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Affiliation(s)
- Stefan R Vink
- Department of Radiation Oncology, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, The Netherlands
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121
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Handrick R, Rübel A, Faltin H, Eibl H, Belka C, Jendrossek V. Increased cytotoxicity of ionizing radiation in combination with membrane-targeted apoptosis modulators involves downregulation of protein kinase B/Akt-mediated survival-signaling. Radiother Oncol 2006; 80:199-206. [PMID: 16916558 DOI: 10.1016/j.radonc.2006.07.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 07/17/2006] [Accepted: 07/19/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND AND PURPOSE The membrane-targeted apoptosis modulators erucylphosphocholine (ErPC) and erucylphosphohomocholine (ErPC3) induce apoptosis in highly apoptosis resistant malignant glioma cell lines and enhance radiation-induced cell death and eradication of clonogenic tumor cells in vitro. Aim of the present study was to elucidate molecular mechanisms of combined action. MATERIALS AND METHODS Induction of apoptosis was evaluated by determination of nuclear morphology (fluorescence microscopy), alteration of mitochondrial function and caspase-activation (flow cytometry, Western blot). Activity of protein kinase B (PKB/Akt) and key downstream effectors involved in apoptosis regulation was verified by Western blot analysis using activation-specific antibodies. RESULTS Increased cytotoxicity of the combination was linked to a more efficient activation of the intrinsic apoptosis pathway with increased damage of the mitochondria and caspase-activation. Moreover, activity of the survival kinase PKB/Akt was downregulated upon treatment with ErPC/ErPC3 alone or in combination with ionizing radiation. Inhibition of PKB/Akt was associated with decreased phosphorylation and thus activation of the pro-apoptotic Bcl-2 protein Bad as well as dephosphorylation of the transcription factor FOXO3A (FKHRL1) that may be responsible for the observed increased expression of the pro-apoptotic Bcl-2 protein Bim. CONCLUSIONS Our data suggest a role for inhibition of PKB/Akt-mediated anti-apoptotic signaling in increased efficacy of the combination.
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Affiliation(s)
- René Handrick
- Department of Radiation Oncology, Experimental Radiation Oncology, University of Tübingen, Tübingen, Germany
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122
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Verma NK, Dey CS. The anti-leishmanial drug miltefosine causes insulin resistance in skeletal muscle cells in vitro. Diabetologia 2006; 49:1656-60. [PMID: 16752184 DOI: 10.1007/s00125-006-0260-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 01/14/2006] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS Miltefosine, the first oral anti-leishmanial drug, is reported to inhibit phosphatidylinositol 3-kinase (PI3K)/Akt activity in carcinoma cell lines. Inhibition of the PI3K/Akt pathway is known to result in insulin resistance. Therefore, we investigated whether miltefosine has any deleterious effect(s) on insulin sensitivity in L6E9 skeletal muscle cells. MATERIALS AND METHODS L6E9 myotubes were treated with miltefosine and its effect was observed on insulin-signalling proteins such as Akt, PI3K, insulin receptor-beta, IRS-1, c-Jun N-terminal kinase, p38 and glycogen synthase kinase beta, as well as on glucose uptake. RESULTS Miltefosine caused skeletal muscle insulin resistance in vitro by interfering with the insulin-signalling pathway and inhibiting insulin-stimulated glucose uptake. CONCLUSIONS/INTERPRETATION Miltefosine may contribute to the risk of type 2 diabetes and needs further clinical exploration.
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Affiliation(s)
- N K Verma
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160062, India
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123
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Vink SR, Lagerwerf S, Mesman E, Schellens JHM, Begg AC, van Blitterswijk WJ, Verheij M. Radiosensitization of squamous cell carcinoma by the alkylphospholipid perifosine in cell culture and xenografts. Clin Cancer Res 2006; 12:1615-22. [PMID: 16533789 DOI: 10.1158/1078-0432.ccr-05-2033] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE Combined modality treatment has improved outcome in various solid tumors. Besides classic anticancer drugs, a new generation of biological response modifiers has emerged that increases the efficacy of radiation. Here, we have investigated whether perifosine, an orally applicable, membrane-targeted alkylphospholipid, enhances the antitumor effect of radiation in vitro and in vivo. EXPERIMENTAL DESIGN Several long-term and short-term in vitro assays (clonogenic survival, sulforhodamine B cytotoxicity, apoptosis, and cell cycle analysis) were used to assess the cytotoxic effect of perifosine in combination with radiation. In vivo, the response of human KB squamous cell carcinoma xenografts was measured after treatment with perifosine, irradiation, and the combination. Radiolabeled perifosine was used to determine drug disposition in tumor and normal tissues. At various intervals after treatment, tumor specimens were collected to document histopathologic changes. RESULTS In vitro, perifosine reduced clonogenic survival, enhanced apoptosis, and increased cell cycle arrest after radiation. In vivo, radiation and perifosine alone induced a dose-dependent tumor growth delay. When combining multiple perifosine administrations with single or split doses of radiation, complete and sustained tumor regression was observed. Histopathologic analysis of tumor specimens revealed a prominent apoptotic response after combined treatment with radiation and perifosine. Radiation-enhanced tumor response was observed at clinically relevant plasma perifosine concentrations and accumulating drug disposition of >100 microg/g in tumor tissue. CONCLUSIONS Perifosine enhances radiation-induced cytotoxicity, as evidenced by reduced clonogenic survival and increased apoptosis induction in vitro and by complete tumor regression in vivo. These data provide strong support for further development of this combination in clinical studies.
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Affiliation(s)
- Stefan R Vink
- Division of Experimental Therapy and Cellular Biochemistry, the Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands
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124
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Heczková B, Slotte JP. Effect of anti-tumor ether lipids on ordered domains in model membranes. FEBS Lett 2006; 580:2471-6. [PMID: 16638573 DOI: 10.1016/j.febslet.2006.03.079] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 03/21/2006] [Accepted: 03/21/2006] [Indexed: 11/29/2022]
Abstract
1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (OMPC, edelfosine) and 1-hexadecylphosphocholine (HePC, miltefosine) represent two groups of synthetic ether lipid analogues with anti-tumor activity. Because of their hydrophobic nature, they may become incorporated into plasma membranes of cells, and it has been argued that they may act via association with lipid rafts. With the quenching of steady-state fluorescence of probes preferentially partitioning into sterol-rich ordered domains (cholestatrienol and trans-parinaric acid), we showed that OMPC and HePC by themselves did not form sterol-rich domains in fluid model membranes, in contrast to the two chain ether lipid 1,2-O-dihexadecyl-sn-glycero-3-phosphocholine. Nevertheless, all three ether lipids significantly stabilized palmitoyl-sphingomyelin/cholesterol-rich domains against temperature induced melting. In conclusion, this study shows that anti-tumor ether lipids are likely to affect the properties of cholesterol-sphingomyelin domains (i.e., lipid rafts) when incorporated into cell membranes.
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Affiliation(s)
- Bohdana Heczková
- Department of Biochemistry and Pharmacy, Abo Akademi University, Tykistokatu 6A, 20520 Turku, Finland.
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125
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Horsman MR, Bohm L, Margison GP, Milas L, Rosier JF, Safrany G, Selzer E, Verheij M, Hendry JH. Tumor radiosensitizers--current status of development of various approaches: report of an International Atomic Energy Agency meeting. Int J Radiat Oncol Biol Phys 2006; 64:551-61. [PMID: 16414371 DOI: 10.1016/j.ijrobp.2005.09.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 08/30/2005] [Accepted: 09/29/2005] [Indexed: 01/02/2023]
Abstract
PURPOSE The International Atomic Energy Agency (IAEA) held a Technical Meeting of Consultants to (1) discuss a selection of relatively new agents, not those well-established in clinical practice, that operated through a variety of mechanisms to sensitize tumors to radiation and (2) to compare and contrast their tumor efficacy, normal tissue toxicity, and status of development regarding clinical application. The aim was to advise the IAEA as to which developing agent or class of agents would be worth promoting further, by supporting additional laboratory research or clinical trials, with the eventual goal of improving cancer control rates using radiotherapy, in developing countries in particular. RESULTS The agents under discussion included a wide, but not complete, range of different types of drugs, and antibodies that interfered with molecules in cell signaling pathways. These were contrasted with new molecular antisense and gene therapy strategies. All the drugs discussed have previously been shown to act as tumor cell radiosensitizers or to kill hypoxic cells present in tumors. CONCLUSION Specific recommendations were made for more preclinical studies with certain of the agents and for clinical trials that would be suitable for industrialized countries, as well as trials that were considered more appropriate for developing countries.
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Affiliation(s)
- Michael R Horsman
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
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126
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Torrecillas A, Aroca-Aguilar JD, Aranda FJ, Gajate C, Mollinedo F, Corbalán-García S, de Godos A, Gómez-Fernández JC. Effects of the anti-neoplastic agent ET-18-OCH3 and some analogs on the biophysical properties of model membranes. Int J Pharm 2006; 318:28-40. [PMID: 16624506 DOI: 10.1016/j.ijpharm.2006.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 03/08/2006] [Accepted: 03/10/2006] [Indexed: 10/24/2022]
Abstract
The effect of 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (ET-18-OCH(3), edelfosine), and six other analog asymmetric phosholipids on the physical properties of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) model membranes was studied using differential scanning calorimetry (DSC), (31)P-nuclear magnetic resonance ((31)P NMR) and X-ray diffraction. DSC data revealed that, at concentrations of 40mol% and higher, a new type of mixtures with higher T(c) and narrower transitions appeared with all the asymmetric lipids studied. At very high concentrations of these lipids (50-80 mol%), destabilization was observed in the systems probably because of the formation of micelles or small vesicles. In all cases, the asymmetric lipids at concentrations of 40 mol% induced the formation of interdigitated structures in the lamellar gel phase, as deduced from X-ray diffraction. The asymmetric phospholipids were also added to 1,2-dielaidoyl-sn-glycero-3-phosphoethanolamine (DEPE) model membranes and DSC data revealed that the lipids primarily affected transition from the lamellar gel (L(beta)) to the lamellar liquid crystalline (L(alpha)) phase in two aspects: the transition temperature was reduced, and the transition itself became broader and smaller. The lamellar liquid crystalline (L(alpha)) to inverted hexagonal phase (H(II)) transition was also affected, as detected by DSC and (31)P NMR data. Increasing concentrations of the asymmetric lipids reduced the formation of inverted hexagonal phases, which were completely inhibited in the case of ET-18-OCH(3). Since these compounds have been shown to have important biological actions through the plasma membrane, these results may help to understand the mechanism of action of these compounds. In addition these asymmetric lipids were tested for their capacity to induce cell apoptosis, and only ET-18-OCH(3) was found to have a clear effect, thus suggesting that the apoptotic effect is not exerted through changes in the biophysical properties of model membranes.
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Affiliation(s)
- Alejandro Torrecillas
- Departamento de Bioquímica y Biología Molecular A, Facultad de Veterinaria, Universidad de Murcia, Apartado de Correos 4021, E-30080 Murcia, Spain
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127
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Gills JJ, Holbeck S, Hollingshead M, Hewitt SM, Kozikowski AP, Dennis PA. Spectrum of activity and molecular correlates of response to phosphatidylinositol ether lipid analogues, novel lipid-based inhibitors of Akt. Mol Cancer Ther 2006; 5:713-22. [PMID: 16546986 DOI: 10.1158/1535-7163.mct-05-0484] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The serine/threonine kinase Akt is a promising target in cancer. We previously identified five phosphatidylinositol ether lipid analogues (PIA) that inhibited Akt activation and selectively killed lung and breast cancer cells with high levels of Akt activity. To assess the spectrum of activity in other cell types and to compare PIAs with other inhibitors of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, we compared growth inhibition by PIAs against the PI3K inhibitors LY294002 and wortmannin and the mTOR inhibitor rapamycin in the NCI60 cell line panel. Although each of these compounds inhibited the growth of all the cell lines, distinct patterns were observed. The PIAs were the least potent but the most cytotoxic. The broad spectrum of activity of PIAs was confirmed in vivo in hollow fiber assays. The response to PIAs was significantly correlated with levels of active but not total Akt in the NCI60, as assessed using COMPARE analysis. However, a number of molecular targets were identified whose expression was more highly correlated with sensitivity to PIAs than active Akt. Expression of these molecular targets did not overlap with those that correlated with sensitivity to LY294002, wortmannin, or rapamycin. A COMPARE analysis of the National Cancer Institute chemical screening database revealed that the patterns of activity of PIAs correlated best with patterns of activity of other lipid-based compounds. These studies show that although PIAs are widely active in cancer cells, which correlates with the presence of its intended target, active Akt, PIAs are biologically distinct from other known inhibitors of the PI3K/Akt/mTOR pathway.
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Affiliation(s)
- Joell J Gills
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, Building 8, Room 5101, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
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128
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Li X, Luwor R, Lu Y, Liang K, Fan Z. Enhancement of antitumor activity of the anti-EGF receptor monoclonal antibody cetuximab/C225 by perifosine in PTEN-deficient cancer cells. Oncogene 2006; 25:525-35. [PMID: 16170346 DOI: 10.1038/sj.onc.1209075] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mutational inactivation or deletion of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN)/MMAC1/TEP gene in human cancer cells leads to a constitutively active status of the phosphatidylinositol 3-kinase/Akt pathway in the cells and has been linked to the lack of responses of the cells to the epidermal growth factor (EGF) receptor-targeted therapeutics. Akt is strongly inhibited by perifosine, an orally active alkyl-lysophospholipid currently being evaluated as an anti-cancer agent in phase 1 and 2 clinical trials. To determine whether perifosine may enhance the antitumor activity of the anti-EGF receptor monoclonal antibody cetuximab/C225 in PTEN-deficient cancer cells, we exposed MDA468 breast cancer cells (which contain mutated PTEN gene) and PC3 prostate cancer cells (in which the PTEN gene is deleted) to perifosine and cetuximab, alone and in combination. Treatment of the cells with perifosine reduced baseline levels of phosphorylated Akt, phosphorylated p44/42 mitogen-activated protein kinase (MAPK) and p38MAPK, and increased baseline levels of phosphorylated stress-activated protein kinase (SAPK)/c-jun NH(2)-terminal kinase (JNK). A 72-h exposure of the MDA468 and PC3 cells to perifosine alone resulted in cell death in a dose-dependent manner, which was enhanced by cetuximab. Addition of subtoxic doses of perifosine to cetuximab treatment also enhanced the cetuximab-induced growth inhibition. The combination treatment enhanced the inhibition of phosphorylation of Akt, p44/42MAPK and p38MAPK, but offset the phosphorylation of SAPK/JNK that was activated by perifosine treatment alone. Taken together, the data showed that perifosine enhances the antitumor activity of cetuximab in PTEN-deficient cancer cells. Further evaluation of the combination treatment in preclinical and clinical studies is warranted.
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Affiliation(s)
- X Li
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, 77030, USA
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129
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Wang ZJ, Li GM, Nie BM, Lu Y, Yin M. Neuroprotective effect of the stearic acid against oxidative stress via phosphatidylinositol 3-kinase pathway. Chem Biol Interact 2006; 160:80-7. [PMID: 16448636 DOI: 10.1016/j.cbi.2005.12.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 12/16/2005] [Accepted: 12/16/2005] [Indexed: 10/25/2022]
Abstract
Stearic acid is a long-chain saturated fatty acid consisting of 18 carbon atoms without double bonds. In the present study, we reported the neuroprotective effects and mechanism of stearic acid on cortical or hippocampal slices insulted by oxygen-glucose deprivation, NMDA or hydrogen peroxide (H(2)O(2)) in vitro. Different types of models of brain slice injury in vitro were developed by 10 min of oxygen/glucose deprivation, 0.5 mM NMDA or 2 mM H(2)O(2), respectively. After 30 min of preincubation with stearic acid (3-30 microM), cortical or hippocampal slices were subjected to oxygen-glucose deprivation, NMDA or H(2)O(2). Then the tissue activities were evaluated by using the 2,3,5-triphenyltetrazolium chloride (TTC) method. Population spikes were recorded in randomly selected hippocampal slices. Stearic acid (3-30 microM) dose-dependently protected brain slices from oxygen-glucose deprivation, NMDA and H(2)O(2) insults. Its neuroprotective effect against H(2)O(2) insults can be completely blocked by wortmannin (inhibitor of PI3K) and partially blocked by H7 (inhibitor of PKC) or genistein (inhibitor of TPK). Treatment of cortical or hippocampal slices with 30 microM stearic acid resulted in a significant increase in PI3K activity at 5, 10, 30 and 60 min. These observations reveal that stearic acid can protect cortical or hippocampal slices against injury induced by oxygen-glucose deprivation, NMDA or H(2)O(2), and its neuroprotective effects are via phosphatidylinositol 3-kinase dependent mechanism.
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Affiliation(s)
- Ze-Jian Wang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, PR China
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130
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Hideshima T, Catley L, Yasui H, Ishitsuka K, Raje N, Mitsiades C, Podar K, Munshi NC, Chauhan D, Richardson PG, Anderson KC. Perifosine, an oral bioactive novel alkylphospholipid, inhibits Akt and induces in vitro and in vivo cytotoxicity in human multiple myeloma cells. Blood 2006; 107:4053-62. [PMID: 16418332 PMCID: PMC1895278 DOI: 10.1182/blood-2005-08-3434] [Citation(s) in RCA: 352] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Perifosine is a synthetic novel alkylphospholipid, a new class of antitumor agents which targets cell membranes and inhibits Akt activation. Here we show that baseline phosphorylation of Akt in multiple myeloma (MM) cells is completely inhibited by perifosine [octadecyl-(1,1-dimethyl-piperidinio-4-yl)-phosphate] in a time- and dose-dependent fashion, without inhibiting phosphoinositide-dependent protein kinase 1 phosphorylation. Perifosine induces significant cytotoxicity in both MM cell lines and patient MM cells resistant to conventional therapeutic agents. Perifosine does not induce cytotoxicity in peripheral blood mononuclear cells. Neither exogenous interleukin-6 (IL-6) nor insulinlike growth factor 1 (IGF-1) overcomes Perifosine-induced cytotoxicity. Importantly, Perifosine induces apoptosis even of MM cells adherent to bone marrow stromal cells. Perifosine triggers c-Jun N-terminal kinase (JNK) activation, followed by caspase-8/9 and poly (ADP)-ribose polymerase cleavage. Inhibition of JNK abrogates perifosine-induced cytotoxicity, suggesting that JNK plays an essential role in perifosine-induced apoptosis. Interestingly, phosphorylation of extracellular signal-related kinase (ERK) is increased by perifosine; conversely, MEK inhibitor synergistically enhances Perifosine-induced cytotoxicity in MM cells. Furthermore, perifosine augments dexamethasone, doxorubicin, melphalan, and bortezomib-induced MM cell cytotoxicity. Finally, perifosine demonstrates significant antitumor activity in a human plasmacytoma mouse model, associated with down-regulation of Akt phosphorylation in tumor cells. Taken together, our data provide the rationale for clinical trials of perifosine to improve patient outcome in MM.
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Affiliation(s)
- Teru Hideshima
- Jerome Lipper Multiple Myeloma Center, Department of Medical Oncology, Dana-Farber Cancer Institute, Mayer 557, 44 Binney Street, Boston, MA 02115, USA
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131
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Bailey HH, Mahoney MR, Ettinger DS, Maples WJ, Fracasso PM, Traynor AM, Erlichman C, Okuno SH. Phase II study of daily oral perifosine in patients with advanced soft tissue sarcoma. Cancer 2006; 107:2462-7. [PMID: 17058289 DOI: 10.1002/cncr.22308] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND A multicenter Phase II study was performed to evaluate the clinical activity of an initial loading (150 mg every 6 hours x 4 doses) dose followed by continuous daily oral dosing (100 mg/day) of perifosine in patients with advanced soft tissue sarcomas (STSs). METHODS Patients with measurable metastatic STS received perifosine as first-, second-, or third-line treatment and underwent disease assessment every 8 weeks until disease progression, excessive toxicity, or patient refusal. RESULTS Twenty-three patients received 66 cycles (1 cycle = 4 weeks) of perifosine. One partial response of 9 months duration was observed. The overall 3 and 6 month progression-free survival was 22% and 9%. NCI CTC (v2.0) Grade 1 to 2 gastrointestinal toxicity or fatigue were the most common (>50% of subjects) toxicities observed. The steady-state plasma perifosine levels (Css) were similar to prior experience (mean 6 microg/mL). Patients with Css levels >6 microg/mL appeared more likely to remain on study past 2 months than those with levels <6 microg/mL. CONCLUSIONS Despite not achieving the primary objective of > or =40% 6-month progression-free survival rate, optimism remains for this agent in STS patients. Prolonged responses in heavily pretreated STS patients continue to be observed with perifosine treatment. Continued assessment of perifosine in STS appears warranted, with special attention to specific histologies or tumor characteristics that might identify a more sensitive population and achieving perifosine Css levels >6 microg/mL.
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Affiliation(s)
- Howard H Bailey
- University of Wisconsin Comprehensive Cancer Center, Madison, Wisconsin 53792, USA.
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132
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Momota H, Nerio E, Holland EC. Perifosine inhibits multiple signaling pathways in glial progenitors and cooperates with temozolomide to arrest cell proliferation in gliomas in vivo. Cancer Res 2005; 65:7429-35. [PMID: 16103096 DOI: 10.1158/0008-5472.can-05-1042] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Perifosine is an oral Akt inhibitor which exerts a marked cytotoxic effect on human tumor cell lines, and is currently being tested in several phase II trials for treatment of major human cancers. However, the efficacy of perifosine in human gliomas has not been established. As Akt is activated in approximately 70% of human glioblastomas, we investigated the impact of perifosine on glia in culture and on a mouse glioma model in vivo. Here we show that perifosine strongly reduces phosphorylation levels of Akt and extracellular signal-regulated kinase (Erk) 1/2, induces cell cycle arrest in G1 and G2, and causes dose-dependent growth inhibition of mouse glial progenitors in which Akt and/or Ras-Erk 1/2 pathways are activated. Furthermore, because temozolomide is a common oral alkylating agent used in the treatment of gliomas, we investigated the effect of perifosine in combination with temozolomide. We observed an enhanced effect when both were used in culture. With these results, we combined perifosine and temozolomide as treatment of platelet-derived growth factor B-driven gliomas in mice. Animal studies showed that perifosine and temozolomide combination therapy was more effective than temozolomide treatment alone (P < 0.01). These results indicate that perifosine is an effective drug in gliomas in which Akt and Ras-Erk 1/2 pathways are frequently activated, and may be a new candidate for glioma treatment in the clinic.
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Affiliation(s)
- Hiroyuki Momota
- Department of Cancer Biology and Genetics and Surgery (Neurosurgery) and Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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133
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Andresen TL, Jensen SS, Madsen R, Jørgensen K. Synthesis and Biological Activity of Anticancer Ether Lipids That Are Specifically Released by Phospholipase A2 in Tumor Tissue. J Med Chem 2005; 48:7305-14. [PMID: 16279790 DOI: 10.1021/jm049006f] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The clinical use of anticancer lipids is severely limited by their ability to cause lysis of red blood cells prohibiting intravenous injection. Novel delivery systems are therefore required in order to develop anticancer ether lipids (AELs) into clinically useful anticancer drugs. In a recent article (J. Med. Chem. 2004, 47, 1694) we showed that it is possible to construct liposome systems composed of masked AELs that are activated by secretory phospholipase A2 in cancerous tissue. We present here the synthesis of six AELs and evaluate the biological activity of these bioactive lipids. The synthesized AEL 1-6 were tested against three different cancer cell lines. It was found that the stereochemistry of the glycerol headgroup in AEL-2 and 3 has a dramatic effect on the cytotoxicity of the lipids. AEL 1-4 were furthermore evaluated for their ability to prevent phosphorylation of the apoptosis regulating kinase Akt, and a correlation was found between their cytotoxic activity and their ability to inhibit Akt phosphorylation.
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Affiliation(s)
- Thomas L Andresen
- Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Lyngby, Denmark.
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134
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Gao N, Rahmani M, Shi X, Dent P, Grant S. Synergistic antileukemic interactions between 2-medroxyestradiol (2-ME) and histone deacetylase inhibitors involve Akt down-regulation and oxidative stress. Blood 2005; 107:241-9. [PMID: 16141349 PMCID: PMC1895355 DOI: 10.1182/blood-2005-06-2409] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Interactions between the endogenous estradiol metabolite 2-medroxyestradiol (2-ME) and histone deacetylase inhibitors (HDACIs) have been investigated in human leukemia cells. Coadministration of subtoxic or marginally toxic concentrations of 2-ME and SAHA or sodium butyrate in diverse human leukemia-cell types resulted in a marked increase in oxidative damage (eg, generation of reactive oxygen species [ROSs]), mitochondrial injury (eg, cytochrome c release and Bax translocation), caspase activation, and apoptosis. These interactions were also noted in primary human leukemia cells but not in normal bone marrow CD34+ cells. Synergistic interactions between these agents were associated with inactivation of Akt and activation of c-Jun N-terminal kinase (JNK). Essentially all of these events were reversed by free radical scavengers such as the manganese superoxide dismutase (MnSOD) mimetic TBAP and catalase. Notably, treatment with 2-ME/HDACIs resulted in down-regulation of thioredoxin, MnSOD, and glutathione peroxidase. Enforced activation of Akt blocked 2-ME/HDACI-mediated mitochondrial injury, caspase activation, and JNK up-regulation, but not generation of ROSs. Pharmacologic or genetic (siRNA) interruption of the JNK pathway also significantly attenuated the lethality of this regimen. Together, these findings support a model in which antileukemic synergism between 2-ME and HDACIs stems primarily from induction of oxidative damage, leading in turn to Akt inactivation and JNK activation, culminating in mitochondrial injury and apoptosis. They also raise the possibility that these events may preferentially occur in leukemic versus normal hematopoietic cells.
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Affiliation(s)
- Ning Gao
- Department of Medicine, Virginia Commonwealth University/Medical College of Virginia, Richmond, VA, USA
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135
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Vink SR, Schellens JHM, van Blitterswijk WJ, Verheij M. Tumor and normal tissue pharmacokinetics of perifosine, an oral anti-cancer alkylphospholipid. Invest New Drugs 2005; 23:279-86. [PMID: 16012787 DOI: 10.1007/s10637-005-1436-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Clinical use of anti-cancer alkylphospholipids is limited by gastrointestinal toxicity. However, new interest has emerged since it was shown that these drugs enhance the cytotoxic effect of conventional chemotherapy and radiotherapy in preclinical models. The aim of this study was to characterize the pharmacokinetic profile of perifosine, an oral analog of alkylphosphocholine (APC), and to compare in vitro drug uptake with in vivo drug accumulation in three human-derived squamous cell carcinomas (A431, HNXOE and KB). In vitro, KB cells showed a remarkably high uptake and sensitivity for perifosine compared with A431 and HNXOE cells. In vivo, perifosine reached a clinically relevant plasma concentration in mice after a single oral dose of 40 mg/kg. Perifosine was not metabolized and displayed slow elimination, with a terminal half-life of 137 (+/- 20) hours and an apparent volume of distribution of 11.3 l/kg. Comparable tumor accumulation was observed for A431 and HNXOE tumors, whereas perifosine uptake by KB xenografts was substantially higher. Tissue distribution occurred throughout the whole body reaching high perifosine levels in the gastro-intestinal tract, while heart and brain tissue contained relatively low levels. Based on its stability and relatively high tumor uptake in vivo, perifosine is an attractive candidate for further evaluation, e.g. as radiosensitizer.
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Affiliation(s)
- Stefan R Vink
- Division of Experimental Therapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
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136
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Hoyer KK, Herling M, Bagrintseva K, Dawson DW, French SW, Renard M, Weinger JG, Jones D, Teitell MA. T Cell Leukemia-1 Modulates TCR Signal Strength and IFN-γ Levels through Phosphatidylinositol 3-Kinase and Protein Kinase C Pathway Activation. THE JOURNAL OF IMMUNOLOGY 2005; 175:864-73. [PMID: 16002684 DOI: 10.4049/jimmunol.175.2.864] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A signaling role for T cell leukemia-1 (TCL1) during T cell development or in premalignant T cell expansions and mature T cell tumors is unknown. In this study, TCL1 is shown to regulate the growth and survival of peripheral T cells but not precursor thymocytes. Proliferation is increased by TCL1-induced lowering of the TCR threshold for CD4(+) and CD8(+) T cell activation through both PI3K-Akt and protein kinase C-MAPK-ERK signaling pathways. This effect is submaximal as CD28 costimulation coupled to TCL1 expression additively accelerates dose-dependent T cell growth. In addition to its role in T cell proliferation, TCL1 also increases IFN-gamma levels from Th1-differentiated T cells, an effect that may provide a survival advantage during premalignant T cell expansions and in clonal T cell tumors. Combined, these data indicate a role for TCL1 control of growth and effector T cell functions, paralleling features provided by TCR-CD28 costimulation. These results also provide a more detailed mechanism for TCL1-augmented signaling and help explain the delayed occurrence of mature T cell expansions and leukemias despite tumorigenic TCL1 dysregulation that begins in early thymocytes.
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MESH Headings
- Animals
- Antigens, Surface/metabolism
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/enzymology
- CD4-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/enzymology
- CD8-Positive T-Lymphocytes/immunology
- Cell Differentiation/immunology
- Cell Line, Tumor
- Cell Proliferation
- Cell Survival/immunology
- Cells, Cultured
- Enzyme Activation/immunology
- Humans
- Interferon-gamma/biosynthesis
- Interferon-gamma/metabolism
- Jurkat Cells
- Leukemia, T-Cell/enzymology
- Leukemia, T-Cell/immunology
- Leukemia, T-Cell/pathology
- MAP Kinase Signaling System/immunology
- Mice
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphatidylinositol 3-Kinases/physiology
- Protein Kinase C/metabolism
- Protein Kinase C/physiology
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins/physiology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- Stem Cells/cytology
- Stem Cells/enzymology
- Stem Cells/immunology
- T-Lymphocytes/cytology
- T-Lymphocytes/enzymology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Th1 Cells/cytology
- Th1 Cells/enzymology
- Th1 Cells/immunology
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Affiliation(s)
- Katrina K Hoyer
- Department of Pathology and Laboratory Medicine, Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA
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137
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Abstract
Oncogenic transformation leads to cell cycle aberration and apoptosis dysregulation. Targeting cell cycle and apoptosis pathways has emerged as an attractive approach for the treatment of cancer. The activity of cdks can be modulated by targeting these kinases with small molecules that bind to the ATP binding pocket of cdks, or by altering the composition of the cdk/endogenous cdk inhibitor complexes by different mechanisms. Apoptosis can be modulated by targeting pro-apoptotic or pro-survival pathways. Several proteins relevant to oncogenic and proliferative processes, such as p53, bcl-2, AKT, ras and epidermal growth factor receptor, are also important in blocking apoptosis. Several small molecules that modulate cell cycle control and apoptosis have been approved recently and many will be approved in the near future. Several challenges remain, including finding ways of targeting these agents specifically to tumors (sparing normal cells), and the development of rationales for combining these new agents with standard therapies and for prioritizing the development of an overwhelming number of novel small molecules targeting cell cycle and apoptosis. Novel technologies such as genomics and proteomics will be instrumental in designing combinatorial regimens tailored to patients on the basis of the genetic makeup of tumors. Irrespective of all shortcomings, the future of modulation of apoptosis and cell cycle machinery for oncology therapy is quite exciting.
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Affiliation(s)
- Adrian M Senderowicz
- Molecular Therapeutics Unit Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Building 30, Room 212, Bethesda, Maryland 20892, USA.
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138
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Rahmani M, Reese E, Dai Y, Bauer C, Payne SG, Dent P, Spiegel S, Grant S. Coadministration of Histone Deacetylase Inhibitors and Perifosine Synergistically Induces Apoptosis in Human Leukemia Cells through Akt and ERK1/2 Inactivation and the Generation of Ceramide and Reactive Oxygen Species. Cancer Res 2005; 65:2422-32. [PMID: 15781658 DOI: 10.1158/0008-5472.can-04-2440] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Interactions between histone deacetylase inhibitors (HDACIs) and the alkyl-lysophospholipid perifosine were examined in human leukemia cells. Coadministration of sodium butyrate, suberoylanilide hydroxamic acid (SAHA), or trichostatin with perifosine synergistically induced mitochondrial dysfunction (cytochrome c and apoptosis-inducing factor release), caspase-3 and -8 activation, apoptosis, and a marked decrease in cell growth in U937 as well as HL-60 and Jurkat leukemia cells. These events were associated with inactivation of extracellular signal-regulated kinase (ERK) 1/2 and Akt, p46 c-jun-NH2-kinase (JNK) activation, and a pronounced increase in generation of ceramide and reactive oxygen species (ROS). They were also associated with up-regulation of Bak and a marked conformational change in Bax accompanied by membrane translocation. Ectopic expression of Bcl-2 delayed but was ultimately ineffective in preventing perifosine/HDACI-mediated apoptosis. Enforced expression of constitutively active mitogen-activated protein kinase kinase (MEK) 1 or myristoylated Akt blocked HDACI/perifosine-mediated ceramide production and cell death, suggesting that MEK/ERK and Akt inactivation play a primary role in these phenomena. However, inhibition of JNK activation (e.g., by the JNK inhibitor SP600125) did not attenuate sodium butyrate/perifosine-induced apoptosis. In addition, the free radical scavenger N-acetyl-L-cysteine attenuated ROS generation and apoptosis mediated by combined treatment. Finally, the acidic sphingomyelinase inhibitor desipramine attenuated HDACI/perifosine-mediated ceramide and ROS production as well as cell death. Together, these findings indicate that coadministration of HDACIs with perifosine in human leukemia cells leads to Akt and MEK/ERK disruption, a marked increase in ceramide and ROS production, and a striking increase in mitochondrial injury and apoptosis. They also raise the possibility that combining these agents may represent a novel antileukemic strategy.
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Affiliation(s)
- Mohamed Rahmani
- Department of Medicine, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
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139
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Butler MS. Natural products to drugs: natural product derived compounds in clinical trials. Nat Prod Rep 2005; 22:162-95. [PMID: 15806196 DOI: 10.1039/b402985m] [Citation(s) in RCA: 339] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Natural product and natural product-derived compounds that are being evaluated in clinical trials or in registration (current 31 December 2004) have been reviewed. Natural product derived drugs launched in the United States of America, Europe and Japan since 1998 and new natural product templates discovered since 1990 are discussed.
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Affiliation(s)
- Mark S Butler
- MerLion Pharmaceuticals, 1 Science Park Road, The Capricorn #05-01, Singapore Science Park II, Singapore 117528.
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140
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Drees BE, Mills GB, Rommel C, Prestwich GD. Therapeutic potential of phosphoinositide 3-kinase inhibitors. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.14.5.703] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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141
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Affiliation(s)
- J E Dancey
- Investigational Drug Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Rockville, MD, USA
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142
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AKT Kinase and Hsp90 Inhibitors as Novel Anti-cancer Therapeutics. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2005. [DOI: 10.1016/s0065-7743(05)40017-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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143
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Bittman R. The 2003 ASBMB-Avanti Award in Lipids Address: Applications of novel synthetic lipids to biological problems. Chem Phys Lipids 2004; 129:111-31. [PMID: 15081855 DOI: 10.1016/j.chemphyslip.2004.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2004] [Revised: 01/24/2004] [Accepted: 01/28/2004] [Indexed: 01/10/2023]
Abstract
This paper is an overview of the 2003 Avanti Award in Lipids address that was presented by Robert Bittman at the American Society for Biochemistry and Molecular Biology (ASBMB) Annual Meeting held in San Diego, CA in conjunction with meetings of five other FASEB Societies, April 15, 2003. The theme of the lecture is: "How can the chemical synthesis of unnatural lipids provide insights into problems ranging from cell biology to biophysics?" The following examples are presented: (1) novel ceramide analogs as experimental anticancer agents, (2) photoactivatable sphingosine 1-phosphate analogs as probes of protein targets of this bioactive lipid, (3) a 13C-enriched cerebroside as a quantitative probe of glycosphingolipid (GSL) transbilayer distribution in bilayers with and without sphingomyelin, (4) cis and trans unsaturated sphingomyelin analogs as modulators of the existence of cholesterol-enriched microdomains (rafts) that may facilitate fusion of alphaviruses with target membranes, (5) ceramide as an indirect enhancer of the permeabilization of membranes induced by cholesterol-specific cytolysins, (6) fluorescent GSL analogs of widely disparate structure as probes of the molecular features responsible for the selective internalization of GSLs in caveolae of living mammalian cells, (7) enantiomeric lysophosphatidic acid (LPA) analogs as probes of receptor subtypes that mediate LPA signaling, and (8) phosphonocholine analogs of the antitumor ether lipid ET-18-OCH3 as tools for discerning the primary targets that are critical for cytotoxic activity in tumor cells.
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Affiliation(s)
- Robert Bittman
- Department of Chemistry and Biochemistry, Queens College and The Graduate School of The City University of New York, Flushing, NY 11367, USA.
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144
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Van Ummersen L, Binger K, Volkman J, Marnocha R, Tutsch K, Kolesar J, Arzoomanian R, Alberti D, Wilding G. A Phase I Trial of Perifosine (NSC 639966) on a Loading Dose/Maintenance Dose Schedule in Patients with Advanced Cancer. Clin Cancer Res 2004; 10:7450-6. [PMID: 15569974 DOI: 10.1158/1078-0432.ccr-03-0406] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Perifosine (NSC 639966) is a synthetic, substituted heterocyclic alkylphosphocholine that acts primarily at the cell membrane targeting signal transduction pathways. Early clinical trials were limited because of dose-limiting gastrointestinal toxicity, and parenteral dosing of this class of agents is not possible because of their hemolytic properties; therefore, related compounds with an improved therapeutic index were developed. Toxicity was minimized and efficacy improved by using a loading dose/maintenance dose schedule, and therefore, this schedule was carried into clinical trials. This phase I trial enrolled 42 patients with incurable solid malignancies. The starting doses were 100 mg p.o. x four doses (every 6 hours) load followed by a 50 mg p.o. once daily maintenance dose with escalation of either component in successive dose levels. No treatment related deaths occurred. The maximum-tolerated dose was determined to be 150 mg p.o. x four doses load and 100 mg p.o. once daily maintenance. Dose-limiting toxicities such as nausea, diarrhea, dehydration, and fatigue were seen early during the loading phase and were surmountable with the use of prophylactic 5-HT3 receptor antagonists, dexamethasone, and loperamide. Toxicities during the chronic phase were difficult to manage and, given that pharmacokinetic data showed biologically active serum concentrations (based on preclinical data), raised the question of less frequent maintenance dosing. Pharmacokinetic data confirmed the maintenance of stable drug levels with chronic dosing and the long half-life. One partial response was seen, as were multiple patients with stable disease beyond course 2. These results suggest perifosine activity in sarcoma and perhaps renal cell carcinoma (stable disease in two patients who continued for 6 and 14 courses), thus justifying additional investigation of this agent in a phase II sarcoma trial.
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Affiliation(s)
- Lynn Van Ummersen
- Department of Medicine, University of Wisconsin, University of Wisconsin Comprehensive Cancer Center, Madison, Wisconsin 53792, USA.
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145
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Wright MM, Howe AG, Zaremberg V. Cell membranes and apoptosis: role of cardiolipin, phosphatidylcholine, and anticancer lipid analogues. Biochem Cell Biol 2004; 82:18-26. [PMID: 15052325 DOI: 10.1139/o03-092] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The apoptotic program utilizes cellular membranes to transduce and generate operative signals. Lipids are major components of cellular membranes and have the potential to control the effectiveness of the signal by directing it to the proper location, being a source of new signals or as mediators in the response. These possible lipid functions are illustrated in the present review, focussing on the role that two different phospholipids, cardiolipin and phosphatidyl choline, play in apoptosis. Mitochondria have a central role in apoptosis, and many important aspects of the process mediated by this organelle converge through its distinctive lipid cardiolipin. Specifically, changes in cardiolipin metabolism have been detected in early steps of the death program and it is postulated (i) to mediate recruitment of pro apoptotic proteins like Bid to the mitochondria surface and (ii) to actively participate in the release of proteins relevant for the execution phase of apoptosis, like cytochrome c. Unlike the organelle specific distribution of cardiolipin, phosphatidylcholine is widely distributed among all organelles of the cell. The importance of phosphatidylcholine in apoptosis has been approached mainly through the study of the mode of action of (i) phosphatidylcholine anticancer analogues such as edelfosine and (ii) molecules that alter phosphatidylcholine metabolism, such as farnesol. The contribution of phosphatidylcholine metabolism to the apoptotic program is discussed, analyzing the experimental evidence available and pointing out some controversies in the proposed mechanisms of action.
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Affiliation(s)
- Marcia M Wright
- Department of Pediatrics, Atlantic Research Centre, Dalhousie University, Halifax, NS, Canada
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146
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Jordan CT, Guzman ML. Mechanisms controlling pathogenesis and survival of leukemic stem cells. Oncogene 2004; 23:7178-87. [PMID: 15378078 DOI: 10.1038/sj.onc.1207935] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stem cells are an integral component of normal mammalian physiology and have been intensively studied in many systems. Intriguingly, substantial evidence indicates that stem cells also play an important role in the initiation and pathogenesis of at least some cancers. In particular, myeloid leukemias have been extensively characterized with regard to stem and progenitor cell involvement. Thus, as a focal point for both scientific and therapeutic endeavors, leukemic stem cells (LSC) represent a critical area of investigation. LSC appear to retain many characteristics of normal hematopoietic stem cells (HSC) as evidenced by a hierarchical developmental pattern, a mostly quiescent cell cycle profile, and an immunophenotype very similar to HSC. Consequently, defining unique properties of LSC remains a high priority in order to elucidate the molecular mechanisms driving stem cell transformation, and for developing therapeutic strategies that specifically target the LSC population. In this review, we discuss emerging concepts in the field and describe how various molecular and cellular characteristics of leukemia cells might be exploited as a means to preferentially ablate malignant stem cells.
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Affiliation(s)
- Craig T Jordan
- Department of Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 703, NY 14642, USA.
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147
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Verma NK, Dey CS. Possible mechanism of miltefosine-mediated death of Leishmania donovani. Antimicrob Agents Chemother 2004; 48:3010-5. [PMID: 15273114 PMCID: PMC478494 DOI: 10.1128/aac.48.8.3010-3015.2004] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Miltefosine causes leishmanial death, but the possible mechanism(s) of action is not known. The mode of action of miltefosine was investigated in vitro in Leishmania donovani promastigotes as well as in extra- and intracellular amastigotes. Here, we demonstrate that miltefosine induces apoptosis-like death in L. donovani based on observed phenomena such as nuclear DNA condensation, DNA fragmentation with accompanying ladder formation, and in situ labeling of DNA fragments by the terminal deoxyribonucleotidyltransferase-mediated dUTP-biotin nick end labeling method. Understanding of miltefosine-mediated death will facilitate the design of new therapeutic strategies against Leishmania parasites.
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Affiliation(s)
- Navin K Verma
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
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148
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Dasmahapatra GP, Didolkar P, Alley MC, Ghosh S, Sausville EA, Roy KK. In vitroCombination Treatment with Perifosine and UCN-01 Demonstrates Synergism against Prostate (PC-3) and Lung (A549) Epithelial Adenocarcinoma Cell Lines. Clin Cancer Res 2004; 10:5242-52. [PMID: 15297428 DOI: 10.1158/1078-0432.ccr-03-0534] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Antineoplastic agents often achieve antitumor activity at the expense of close to unacceptable toxicity. One potential avenue to improve therapeutic index might combine agents targeting distinct components of the same growth regulatory pathway. This might lead to more complete modulation of the target pathway at concentrations lower than those associated with limiting adventitious toxicities from either agent alone. The protein kinase antagonist UCN-01 is currently used in Phase I/II trials and has recently been demonstrated to inhibit potently PDK1. We have recently documented that the alkylphospholipid perifosine potently also inhibits Akt kinase (PKB) activation by interfering with membrane localization of Akt. This leads to the hypothesis that these two agents might act synergistically through distinct mechanisms in the PI3K/Akt proliferation and survival-related signaling pathway. EXPERIMENTAL DESIGN The synergistic effects of UCN-01 and perifosine, on two cell lines (A-549 and PC-3), were examined using various long-term in vitro assays for cell growth, cell cycle distribution, clonogenicity, survival morphology, and apoptosis. Along with Western blotting experiments were performed to determine whether this synergistic combination of two drugs has significant effect on their downstream targets and on biochemical markers of apoptosis. RESULTS After 72 h, perifosine at concentrations of 1.5 and 10 microM UCN-01 at 40 and 250 nM did not significantly affect the growth of PC-3 and A459 cells, respectively. However, in combination at the same respective individual concentrations (1.5 microM and 40 nM of perifosine and UCN-01, respectively, in PC-3 cells and 10 microM perifosine and 0.25 microM UCN-01 in the somewhat more resistant A549 cells), virtually complete growth inhibition of both the cell lines resulted. Supra-additive inhibition of growth was also demonstrated in independent clonogenic assays. Mechanistic studies in cell culture models suggest enhanced depletion of the S-phase population in cells treated by the combination. This correlated with enhanced inactivation of Akt along with activation of caspases 3 and 9 and poly(ADP-ribose) polymerase cleavage. Evidence of synergy was formally demonstrated and occurred across a wide range of drug concentrations and was largely independent of the order or sequence of drug addition. CONCLUSIONS As the concentrations of UCN-01 and perifosine causing synergistic inhibition of cell growth are clinically achievable without prominent toxicity, these data support the development of clinical studies with this combination.
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Affiliation(s)
- Girija P Dasmahapatra
- Clinical Trials Unit, Developmental Therapeutics Program, National Cancer Institute, Bethesda, Maryland 20892, USA
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149
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Belka C, Jendrossek V, Pruschy M, Vink S, Verheij M, Budach W. Apoptosis-modulating agents in combination with radiotherapy-current status and outlook. Int J Radiat Oncol Biol Phys 2004; 58:542-54. [PMID: 14751526 DOI: 10.1016/j.ijrobp.2003.09.067] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE To increase the therapeutic efficacy of ionizing radiation or to reduce radiation-mediated side effects, diverse research centers for translational radiation oncology have headed for a specific modulation of defined cellular death pathways. In this regard, several signaling systems have proved to be of high potential value. RESULTS It has previously been shown that apoptotic pathways induced by ionizing radiation are distinct from death pathways triggered by death ligands such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). The combination of both radiation and TRAIL was highly efficient in vitro and in preclinical mouse models. However, several aspects of normal tissue toxicity have not been solved, and no Phase I data are available yet. A second approach tested in a Phase I trial is based on the observation that synthetic phospholipid derivatives (alkyllysophospholipids and alkylphosphocholines) strongly enhance apoptotic effects by modulating the balance among the mitogenic, anti-apoptotic MAPK, phosphatidylinositol 3'-kinase (PI3K)/Akt, and the pro-apoptotic SAPK/JNK signaling pathways. Furthermore, others have provided evidence that inhibition of anti-apoptotic signals generated by mitogenic stimuli may increase radiation responses. In this context, controversial data are available regarding the influence of a pharmacologic abrogation of MEK1, Erk1/2 signaling on apoptotic sensitivity but no Phase I trials of MEK inhibitors either alone or in combination with radiation have yet been published. However, inhibition of the PI3K/Akt survival pathway using compounds such as the protein kinase C (PKC) inhibitor PKC412 has been shown to induce apoptosis or to increase the apoptotic sensitivity of tumor cells. Therefore, these drugs may be used alone or in combination with radiation to increase tumor control; however, Phase I data are lacking. Several other drugs, including cyclooxygenase-2 inhibitors, betulinic acid, and proteasome inhibitors, have been shown to interact with apoptotic signal transduction. Again, most of the drugs have not been tested in combination with radiation in vivo or-in the case of cyclooxygenase-2 inhibitors-exert pleiotropic effects. CONCLUSION Although the examples do not reflect all available strategies, it is clear that several promising approaches targeting defined cell death pathways have been developed and entered into clinical trials. The use of synthetic phospholipid derivatives in a Phase I trial is an important example, proving that basic research in radiation biology finally guides the development of new treatment strategies. This, and other approaches, will hopefully increase tumor control rates and reduce side effects in the future.
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Affiliation(s)
- Claus Belka
- Department of Radiation Oncology, Experimental Radiation Oncology, University of Tübingen, Hoppe Seyler Strasse 3, D-72076 Tübingen, Germany.
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