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Abstract
Despite the therapeutic progress, relapse remains a major problem in the treatment of acute lymphoblastic leukemia (ALL). Most leukemia cells that survive chemotherapy are found in the bone marrow (BM), thus resistance to chemotherapy and other treatments may be partially attributed to pro-survival signaling to leukemic cells mediated by leukemia cell-microenvironment interactions. Adhesion of leukemia cells to BM stromal cells may lead to cell adhesion-mediated drug resistance (CAM-DR) mediating intracellular signaling changes that support survival of leukemia cells. In ALL and chronic lymphocytic leukemia (CLL), adhesion-mediated activation of the PI3K/AKT signaling pathway has been shown to be critical in CAM-DR. PI3K targeting inhibitors have been approved for CLL and have been evaluated preclinically in ALL. However, PI3K inhibition has yet to be approved for clinical use in ALL. Here, we review the role of PI3K signaling for normal hematopoietic and leukemia cells and summarize preclinical inhibitors of PI3K in ALL.
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Affiliation(s)
- Hye Na Kim
- Department of Pediatrics, Division of Hematology and Oncology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California, USA
| | - Heather Ogana
- Department of Pediatrics, Division of Hematology and Oncology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California, USA
| | - Vanessa Sanchez
- Department of Pediatrics, Division of Hematology and Oncology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California, USA
| | - Cydney Nichols
- Department of Pediatrics, Division of Hematology and Oncology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California, USA
| | - Yong-Mi Kim
- Department of Pediatrics, Division of Hematology and Oncology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California, USA.
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Zeng M, Ding S, Zhang H, Huang Q, Ren Y, Guo P. Predictive value of integrin α7 for acute myeloid leukemia risk and its correlation with prognosis in acute myeloid leukemia patients. J Clin Lab Anal 2019; 34:e23151. [PMID: 31855276 PMCID: PMC7171313 DOI: 10.1002/jcla.23151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/10/2019] [Accepted: 09/25/2019] [Indexed: 12/18/2022] Open
Abstract
Background This study aimed to explore the predictive value of integrin α7 (ITGA7) for acute myeloid leukemia (AML) risk and subsequently investigate its correlation with risk stratification and prognosis in AML patients. Methods Bone marrow samples were obtained from 196 de novo AML patients prior to initiation of treatment and from 50 subjects underwent bone marrow donation or bone marrow biopsy for non‐hematologic malignant disease (as controls). ITGA7 mRNA and protein expressions were detected by real‐time quantitative polymerase chain reaction and Western blot assays, respectively. In AML patients, the risk stratification was assessed, and complete remission (CR), event‐free survival (EFS), and overall survival (OS) were evaluated. Results Both ITGA7 mRNA and protein expressions were increased in AML patients compared with controls, and their expressions were correlated with poorer risk stratification. For prognosis, ITGA7 mRNA expression and protein expression were declined in CR patients compared to non‐CR patients. Meanwhile, both EFS and OS were shorter in ITGA7 mRNA high expression patients compared to ITGA7 mRNA low expression patients, as well as ITGA7 protein high expression patients compared to ITGA7 protein low expression patients. Conclusion Integrin α7 might serve as a potential biomarker for predicting increased AML risk and worse prognosis in AML patients.
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Affiliation(s)
- Mingyue Zeng
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Siruiyun Ding
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Hui Zhang
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Qianqian Huang
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Yi Ren
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Pengxiang Guo
- Department of Hematology, Guizhou Provincial People's Hospital, Guiyang, China
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Targeting PI3K Signaling in Acute Lymphoblastic Leukemia. Int J Mol Sci 2019; 20:ijms20020412. [PMID: 30669372 PMCID: PMC6358886 DOI: 10.3390/ijms20020412] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/13/2019] [Accepted: 01/14/2019] [Indexed: 01/11/2023] Open
Abstract
Adhesion of acute lymphoblastic leukemia (ALL) cells to bone marrow stroma cells triggers intracellular signals regulating cell-adhesion-mediated drug resistance (CAM-DR). Stromal cell protection of ALL cells has been shown to require active AKT. In chronic lymphocytic leukemia (CLL), adhesion-mediated activation of the PI3K/AKT pathway is reported. A novel FDA-approved PI3Kδ inhibitor, CAL-101/idelalisib, leads to downregulation of p-AKT and increased apoptosis of CLL cells. Recently, two additional PI3K inhibitors have received FDA approval. As the PI3K/AKT pathway is also implicated in adhesion-mediated survival of ALL cells, PI3K inhibitors have been evaluated preclinically in ALL. However, PI3K inhibition has yet to be approved for clinical use in ALL. Here, we review the role of PI3K in normal hematopoietic cells, and in ALL. We focus on summarizing targeting strategies of PI3K in ALL.
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Alasseiri M, Ahmed AU, Williams BRG. Mechanisms and consequences of constitutive activation of integrin-linked kinase in acute myeloid leukemia. Cytokine Growth Factor Rev 2018; 43:1-7. [PMID: 29903521 DOI: 10.1016/j.cytogfr.2018.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 05/31/2018] [Accepted: 06/05/2018] [Indexed: 12/22/2022]
Abstract
Integrin-linked kinase (ILK) has emerged as a critical adaptor and mediator protein in cell signaling pathways that is commonly deregulated in acute myeloid leukemia (AML). This has led to the expectation that therapeutic targeting of ILK may be a useful option in treating leukemia. Although ILK can regulate many cellular processes, including cell differentiation, survival, migration, apoptosis and production of pro-inflammatory cytokines, its role in promoting AML is still unclear. However, its ability to mediate phosphorylation and regulate the important hematopoietic stem cell regulators protein kinase B (AKT) and glycogen synthase kinase-3β supports ILK as an attractive target for the development of novel anticancer therapeutics. In this review, we summarize the existing knowledge of ILK signaling and its impact on cytokines, paying particular attention to the relevance of ILK signaling in AML. We also discuss the rationale for targeting ILK in the treatment of AML and conclude with perspectives on the future of ILK-targeted therapy in AML.
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Affiliation(s)
- Mohammed Alasseiri
- Centre for Cancer Research, Hudson Institute of Medical Research, Clayton, VIC, 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia; Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, University of Tabuk, Tabuk, 71491, Saudi Arabia
| | - Afsar U Ahmed
- Centre for Cancer Research, Hudson Institute of Medical Research, Clayton, VIC, 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia
| | - Bryan R G Williams
- Centre for Cancer Research, Hudson Institute of Medical Research, Clayton, VIC, 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, 3168, Australia.
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5
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Yuan X, Koehn J, Hogge DE. Identification of prognostic subgroups among acute myeloid leukemia patients with intermediate risk cytogenetics using a flow-cytometry-based assessment of ABC-transporter function. Leuk Res 2015; 39:689-95. [PMID: 26002514 DOI: 10.1016/j.leukres.2015.04.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/20/2015] [Accepted: 04/25/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND A median fluorescence intensity ratio (MFIR) which measures the efflux of mitoxantrone (an ATP Binding Cassette (ABC) transporter substrate) with and without ABC transporter inhibition correlates with expression of MDR1 and BCRP in acute myeloid leukemia (AML) blasts. METHODS This study evaluates the impacts of the MFIR on AML outcomes and its interaction with detection of the FLT3 ITD. RESULTS Among 200 newly diagnosed AML patients, an MFIR of ≥ 1.9 (MFIR+) was detected in 60 (30%) leukemic blast samples. In multivariate analysis, MFIR was an independent prognostic factor for response to induction chemotherapy (OR=7.2, P<0.00001), DFS (HR=2.3, P=0.004) and OS (HR=2.2, P=0.0005) with the main effect being in the 141 patients with intermediate risk cytogenetics. Among intermediate risk cytogenetics patients: MFIR+ outcomes were similar to unfavorable cytogenetic risk (CR, 53% vs. 52%, P=1.0; OS, 11 vs. 9 months, P=0.79). MFIR status can further stratify the prognostic risk for patients with or without FLT3 ITD mutation. CONCLUSIONS MFIR has value in predicting outcomes including DFS and OS as well as induction failure. This is particularly true for patients with intermediate risk cytogenetics and when combined with assessment for the FLT3-ITD mutation.
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Affiliation(s)
- XiaoYu Yuan
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada; Department of Hematology, XiangYa Hospital, Central South University, Changsha, China.
| | - Joshua Koehn
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
| | - Donna E Hogge
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada; Department of Medicine, University of British Columbia, Vancouver, Canada
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Kalra J, Dragowska WH, Bally MB. Using Pharmacokinetic Profiles and Digital Quantification of Stained Tissue Microarrays as a Medium-Throughput, Quantitative Method for Measuring the Kinetics of Early Signaling Changes Following Integrin-Linked Kinase Inhibition in an In Vivo Model of Cancer. J Histochem Cytochem 2015; 63:691-709. [PMID: 25940338 PMCID: PMC4804727 DOI: 10.1369/0022155415587978] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/27/2015] [Indexed: 12/24/2022] Open
Abstract
A small molecule inhibitor (QLT0267) targeting integrin-linked kinase is able to slow breast tumor growth in vivo; however, the mechanism of action remains unknown. Understanding how targeting molecules involved in intersecting signaling pathways impact disease is challenging. To facilitate this understanding, we used tumor tissue microarrays (TMA) and digital image analysis for quantification of immunohistochemistry (IHC) in order to investigate how QLT0267 affects signaling pathways in an orthotopic model of breast cancer over time. Female NCR nude mice were inoculated with luciferase-positive human breast tumor cells (LCC6Luc) and tumor growth was assessed by bioluminescent imaging (BLI). The plasma levels of QLT0267 were determined by LC-MS/MS methods following oral dosing of QLT0267 (200 mg/kg). A TMA was constructed using tumor tissue collected at 2, 4, 6, 24, 78 and 168 hr after treatment. IHC methods were used to assess changes in ILK-related signaling. The TMA was digitized, and Aperio ScanScope and ImageScope software were used to provide semi-quantitative assessments of staining levels. Using medium-throughput IHC quantitation, we show that ILK targeting by QLT0267 in vivo influences tumor physiology through transient changes in pathways involving AKT, GSK-3 and TWIST accompanied by the translocation of the pro-apoptotic protein BAD and an increase in Caspase-3 activity.
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Affiliation(s)
- Jessica Kalra
- Experimental Therapeutics BC Cancer Agency, British Columbia, Canada (JK,WHD,MBB),Langara College, Vancouver, British Columbia, Canada (JK)
| | - Weislawa H Dragowska
- Experimental Therapeutics BC Cancer Agency, British Columbia, Canada (JK,WHD,MBB)
| | - Marcel B Bally
- Experimental Therapeutics BC Cancer Agency, British Columbia, Canada (JK,WHD,MBB),Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia (MBB),Department of Biochemistry, University of British Columbia, Vancouver, British Columbia (MBB),Faculty of Pharm. Sciences, University of British Columbia, Vancouver, British Columbia (MBB),Center for Drug Research and Development Vancouver, British Columbia, Canada (MBB)
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Progress in RNAi-mediated Molecular Therapy of Acute and Chronic Myeloid Leukemia. MOLECULAR THERAPY. NUCLEIC ACIDS 2015; 4:e240. [DOI: 10.1038/mtna.2015.13] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/26/2015] [Indexed: 02/08/2023]
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Ahmed AU, Sarvestani ST, Gantier MP, Williams BRG, Hannigan GE. Integrin-linked kinase modulates lipopolysaccharide- and Helicobacter pylori-induced nuclear factor κB-activated tumor necrosis factor-α production via regulation of p65 serine 536 phosphorylation. J Biol Chem 2014; 289:27776-93. [PMID: 25100717 DOI: 10.1074/jbc.m114.574541] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Integrin-linked kinase (ILK) is a ubiquitously expressed and highly conserved serine-threonine protein kinase that regulates cellular responses to a wide variety of extracellular stimuli. ILK is involved in cell-matrix interactions, cytoskeletal organization, and cell signaling. ILK signaling has also been implicated in oncogenesis and progression of cancers. However, its role in the innate immune system remains unknown. Here, we show that ILK mediates pro-inflammatory signaling in response to lipopolysaccharide (LPS). Pharmacological or genetic inhibition of ILK in mouse embryonic fibroblasts and macrophages selectively blocks LPS-induced production of the pro-inflammatory cytokine tumor necrosis factor α (TNF-α). ILK is required for LPS-induced activation of nuclear factor κB (NF-κB) and transcriptional induction of TNF-α. The modulation of LPS-induced TNF-α synthesis by ILK does not involve the classical NF-κB pathway, because IκB-α degradation and p65 nuclear translocation are both unaffected by ILK inhibition. Instead, ILK is involved in an alternative activation of NF-κB signaling by modulating the phosphorylation of p65 at Ser-536. Furthermore, ILK-mediated alternative NF-κB activation through p65 Ser-536 phosphorylation also occurs during Helicobacter pylori infection in macrophages and gastric cancer cells. Moreover, ILK is required for H. pylori-induced TNF-α secretion in macrophages. Although ILK-mediated phosphorylation of p65 at Ser-536 is independent of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway during LPS stimulation, upon H. pylori infection this event is dependent on the PI3K/Akt pathway. Our findings implicate ILK as a critical regulatory molecule for the NF-κB-mediated pro-inflammatory signaling pathway, which is essential for innate immune responses against pathogenic microorganisms.
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Affiliation(s)
- Afsar U Ahmed
- From the Centre for Cancer Research, MIMR-PHI Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia
| | - Soroush T Sarvestani
- From the Centre for Cancer Research, MIMR-PHI Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia
| | - Michael P Gantier
- From the Centre for Cancer Research, MIMR-PHI Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia
| | - Bryan R G Williams
- From the Centre for Cancer Research, MIMR-PHI Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia
| | - Gregory E Hannigan
- From the Centre for Cancer Research, MIMR-PHI Institute of Medical Research, and Department of Molecular and Translational Science, Monash University, Clayton, Victoria 3168, Australia
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Inactivation of the Hippo tumour suppressor pathway by integrin-linked kinase. Nat Commun 2014; 4:2976. [PMID: 24356468 PMCID: PMC3905719 DOI: 10.1038/ncomms3976] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/21/2013] [Indexed: 12/18/2022] Open
Abstract
One of the hallmarks of cancers is the silencing of tumour suppressor genes and pathways. The Hippo tumour suppressor pathway is inactivated in many types of cancers, leading to tumour progression and metastasis. However, the mechanisms of pathway inactivation in tumours remain unclear. Here we demonstrate that integrin-linked kinase (ILK) plays a critical role in the suppression of the Hippo pathway via phospho-inhibition of MYPT1-PP1, leading to inactivation of Merlin. Inhibition of ILK in breast, prostate and colon tumour cells results in the activation of the Hippo pathway components MST1 and LATS1 with concomitant inactivation of YAP/TAZ (Yes-associated protein/transcriptional co-activator with PDZ-binding motif) transcriptional co-activators and TEAD-mediated transcription. Genetic deletion of ILK suppresses ErbB2-driven YAP/TAZ activation in mammary tumours, and its pharmacological inhibition suppresses YAP activation and tumour growth in vivo. Our data demonstrate a role for ILK as a multiple receptor proximal regulator of Hippo tumour suppressor pathway and as a cancer therapeutic target. The Hippo tumour suppressor pathway is inactivated in many cancer types, but how this occurs is unclear. Here, the authors show that integrin-linked kinase (ILK) has a role in inhibiting the Hippo pathway and pharmacological inhibition of ILK reduces the size of tumours in mice.
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Shishido S, Bönig H, Kim YM. Role of integrin alpha4 in drug resistance of leukemia. Front Oncol 2014; 4:99. [PMID: 24904821 PMCID: PMC4033044 DOI: 10.3389/fonc.2014.00099] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 04/22/2014] [Indexed: 11/20/2022] Open
Abstract
Chemotherapeutic drug resistance in acute lymphoblastic leukemia (ALL) is a significant problem, resulting in poor responsiveness to first-line treatment or relapse after transient remission. Classical anti-leukemic drugs are non-specific cell cycle poisons; some more modern drugs target oncogenic pathways in leukemia cells, although in ALL these do not play a very significant role. By contrast, the molecular interactions between microenvironment and leukemia cells are often neglected in the design of novel therapies against drug resistant leukemia. It was shown however, that chemotherapy resistance is promoted in part through cell–cell contact of leukemia cells with bone marrow (BM) stromal cells, also called cell adhesion-mediated drug resistance (CAM-DR). Incomplete response to chemotherapy results in persistence of resistant clones with or without detectable minimal residual disease (MRD). Approaches for how to address CAM-DR and MRD remain elusive. Specifically, studies using anti-functional antibodies and genetic models have identified integrin alpha4 as a critical molecule regulating BM homing and active retention of normal and leukemic cells. Pre-clinical evidence has been provided that interference with alpha4-mediated adhesion of ALL cells can sensitize them to chemotherapy and thus facilitate eradication of ALL cells in an MRD setting. To this end, Andreeff and colleagues recently provided evidence of stroma-induced and alpha4-mediated nuclear factor-κB signaling in leukemia cells, disruption of which depletes leukemia cells of strong survival signals. We here review the available evidence supporting the targeting of alpha4 as a novel strategy for treatment of drug resistant leukemia.
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Affiliation(s)
- Stephanie Shishido
- Division of Hematology and Oncology, Department of Pediatrics, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine , Los Angeles, CA , USA
| | - Halvard Bönig
- Institute for Transfusion Medicine and Immunohematology, German Red Cross Blood Service Baden-Wuerttemberg-Hessen, Goethe University , Frankfurt , Germany
| | - Yong-Mi Kim
- Division of Hematology and Oncology, Department of Pediatrics, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine , Los Angeles, CA , USA
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YUAN YEQING, XIAO YUNBEI, LI QING, LIU ZHENHUA, ZHANG XIAOWEI, QIN CAIPENG, XIE JING, WANG XIAOFENG, XU TAO. In vitro and in vivo effects of short hairpin RNA targeting integrin-linked kinase in prostate cancer cells. Mol Med Rep 2013; 8:419-24. [DOI: 10.3892/mmr.2013.1532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 06/14/2013] [Indexed: 11/06/2022] Open
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12
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Nishioka C, Ikezoe T, Furihata M, Yang J, Serada S, Naka T, Nobumoto A, Kataoka S, Tsuda M, Udaka K, Yokoyama A. CD34⁺/CD38⁻ acute myelogenous leukemia cells aberrantly express CD82 which regulates adhesion and survival of leukemia stem cells. Int J Cancer 2012; 132:2006-19. [PMID: 23055153 DOI: 10.1002/ijc.27904] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 09/25/2012] [Indexed: 12/22/2022]
Abstract
To identify molecular targets in leukemia stem cells (LSCs), this study compared the protein expression profile of freshly isolated CD34(+) /CD38(-) cells with that of CD34(+) /CD38(+) counterparts from individuals with acute myelogenous leukemia (n = 2, AML) using isobaric tags for relative and absolute quantitation (iTRAQ). A total of 98 proteins were overexpressed, while six proteins were underexpressed in CD34(+) /CD38(-) AML cells compared with their CD34(+) /CD38(+) counterparts. Proteins overexpressed in CD34(+) /CD38(-) AML cells included a number of proteins involved in DNA repair, cell cycle arrest, gland differentiation, antiapoptosis, adhesion, and drug resistance. Aberrant expression of CD82, a family of adhesion molecules, in CD34(+) /CD38(-) AML cells was noted in additional clinical samples (n = 12) by flow cytometry. Importantly, down-regulation of CD82 in CD34(+) /CD38(-) AML cells by a short hairpin RNA (shRNA) inhibited adhesion to fibronectin via up-regulation of matrix metalloproteinases 9 (MMP9) and colony forming ability of these cells as assessed by transwell assay, real-time RT-PCR, and colony forming assay, respectively. Moreover, we found that down-regulation of CD82 in CD34(+) /CD38(-) AML cells by an shRNA significantly impaired engraftment of these cells in severely immunocompromised mice. Taken together, aberrant expression of CD82 might play a role in adhesion of LSCs to bone marrow microenvironment and survival of LSCs. CD82 could be an attractive molecular target to eradicate LSCs.
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Affiliation(s)
- Chie Nishioka
- Department of Immunology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
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Ataie-Kachoie P, Pourgholami MH, Morris DL. Inhibition of the IL-6 signaling pathway: a strategy to combat chronic inflammatory diseases and cancer. Cytokine Growth Factor Rev 2012; 24:163-73. [PMID: 23107589 DOI: 10.1016/j.cytogfr.2012.09.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 09/24/2012] [Indexed: 11/19/2022]
Abstract
Interleukin (IL)-6 is a pro-inflammatory cytokine that produces multifunctional effects. Deregulated IL-6 production and signaling are associated with chronic inflammatory diseases, auto-immunity and cancer. On this basis, inhibition of IL-6 production, its receptors or the signaling pathways are strategies currently being widely pursued to develop novel therapies for a wide range of diseases. This survey aims to provide an updated account of why IL-6 inhibitors are shaping up to become an important class of drugs potentially useful in the treatment of ailments and in particular in inflammation and cancer. In addition we discuss the role of different agents in modulating IL-6 and also recent clinical studies targeting IL-6 in inflammation-mediated diseases and cancer.
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Affiliation(s)
- Parvin Ataie-Kachoie
- University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney, NSW 2217, Australia.
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Liesveld J. Targeting myelogenous leukemia stem cells: role of the circulation. Front Oncol 2012; 2:86. [PMID: 22876360 PMCID: PMC3410612 DOI: 10.3389/fonc.2012.00086] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 07/16/2012] [Indexed: 12/25/2022] Open
Abstract
Unlike stem cells from solid tumors, the stem cells which initiate myelogenous leukemias arise in marrow, an organ with a unique circulation which allows ready access of leukemia cells, including leukemia stem cells (LSCs), to the vasculature. This poses unique problems in the targeting of LSCs since these cells are found circulating in the majority of leukemia cases at diagnosis and are usually not detectable during remission states. Because most cases of leukemia relapse, it is suggested that LSCs remain quiescent in the marrow until they eventually proliferate and circulate again. This indicates that effective targeting of LSCs must occur not only in peripheral circulation but in the micro-circulation of the marrow. Targeting such interactions may overcome cell adhesion-mediated treatment resistance, other multi-drug resistance mechanisms, and opportunities for clonal evolution in the marrow environment. Targeting selectins and integrins, signal transduction mediators, and chemokine/cytokine networks in the marrow micro-circulation may aid in abrogating leukemia-initiating stem cells which contribute to disease relapse. LSCs possess surface antigen profiles and signal transduction activation profiles which may allow differential targeting as compared with normal hematopoietic stem cells.
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Affiliation(s)
- Jane Liesveld
- Hematology/Oncology Division, University of Rochester, Rochester, NY, USA
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Xing Y, Gerhard B, Hogge DE. Selective small molecule inhibitors of p110α and δ isoforms of phosphoinosityl-3-kinase are cytotoxic to human acute myeloid leukemia progenitors. Exp Hematol 2012; 40:922-33. [PMID: 22828407 DOI: 10.1016/j.exphem.2012.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 06/30/2012] [Accepted: 07/16/2012] [Indexed: 10/28/2022]
Abstract
The phosphoinosityl-3-kinase (PI3K) pathway is frequently constitutively active in blast cells from acute myeloid leukemia (AML) patients. RNA and protein from all four catalytic isoforms of PI3K (p110α, β, γ, and δ) were expressed in 38 AML samples, which also showed expression of phosphorylated Akt Ser473, indicating PI3K activation. Initial treatment of 12 AML samples with inhibitors targeting each of the four isoforms demonstrated that p110α and δ inhibition are more effective in killing AML blast colony-forming cells (CFC) than p110β or γ inhibition. In subsequent experiments, AML CFC from 46 patient samples were treated with the p110α and δ selective inhibitors, PI3Kα inhibitor 2 or PCN5603, and dose-dependent progenitor kill and inhibition of phosphorylated Akt Ser473 expression was observed. AML samples were more sensitive to PI3Kα inhibitor 2 and PCN5603 killing than normal bone marrow or normal peripheral blood CFC (median IC(50) for AML and normal CFCs treated with PI3Kα inhibitor 2, 1.8 and 4.3 μM, respectively, and for PCN5603, 1.9 and 6.2 μM, respectively). Furthermore, treatment of AML cells with PCN5603 also decreased survival of more primitive leukemia progenitors identified in long-term culture (AML long-term culture initiating cells), while less toxicity toward normal bone marrow long-term culture initiating cells was observed. Selective inhibition of the p110α and δ isoforms of PI3K kills AML progenitors while causing relative sparing of analogous normal cells.
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Affiliation(s)
- Yan Xing
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.
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Abstract
Integrin-linked kinase (ILK) is a highly evolutionarily conserved intracellular protein that was originally identified as an integrin-interacting protein, and extensive genetic and biochemical studies have shown that ILK expression is vital during both embryonic development and tissue homeostasis. At the cellular and tissue levels, ILK regulates signaling pathways for cell adhesion-mediated cell survival (anoikis), apoptosis, proliferation and mitosis, migration, invasion, and vascularization and tumor angiogenesis. ILK also has central roles in cardiac and smooth-muscle contractility, and ILK dysregulation causes cardiomyopathies in humans. ILK protein levels are increased in several human cancers and often the expression level predicts poor patient outcome. Abundant evidence has accumulated suggesting that, of the diverse functions of ILK, some may require kinase activity whereas others depend on protein-protein interactions and are, therefore, independent of kinase activity. However, the past several years have seen an ongoing debate about whether ILK indeed functions as a protein serine/threonine kinase. This debate centers on the atypical protein kinase domain of ILK, which lacks some amino-acid residues thought to be essential for phosphotransferase activity. However, similar deficiencies are present in the catalytic domains of other kinases now known to possess protein kinase activity. Numerous studies have shown that ILK phosphorylates peptide substrates in vitro, corresponding to ILK-mediated phosphorylations in intact cells, and a recent report characterizing in vitro phosphotransferase activity of highly purified, full-length ILK, accompanied by detailed enzyme kinetic analyses, shows that, at least in vitro, ILK is a bona fide protein kinase. However, several genetic studies suggest that, not all biological functions of ILK require kinase activity, and that it can function as an adaptor/scaffold protein. Here, we review evidence for and against ILK being an active kinase, and provide a framework for strategies to further analyze the kinase and adaptor functions of ILK in different cellular contexts.
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Gao J, Zhu J, Li HY, Pan XY, Jiang R, Chen JX. Small interfering RNA targeting integrin-linked kinase inhibited the growth and induced apoptosis in human bladder cancer cells. Int J Biochem Cell Biol 2011; 43:1294-304. [PMID: 21601006 DOI: 10.1016/j.biocel.2011.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 04/01/2011] [Accepted: 05/04/2011] [Indexed: 12/28/2022]
Abstract
Integrin-linked kinase (ILK), an intracellular serine/threonine kinase, is implicated in cell growth and survival, cell-cycle progression, tumor angiogenesis, and cell apoptosis. Recent studies showed that the expression and activity of ILK increased significantly in many types of solid tumors. However, the exact molecular mechanism of ILK underlie tumor has not been fully ascertained. The purpose of our study was to determine whether knockdown of ILK would inhibit cell growth and induce apoptosis in bladder cancer cells using a plasmid vector based small interfering RNA (siRNA). The experiments showed that knockdown of ILK could remarkably inhibit cell proliferation and growth, regulate cell cycle and induce apoptosis of bladder cancer BIU-87 and EJ cells. We demonstrated that knockdown of ILK inhibited phosphorylation of downstream signaling targets protein kinase B/Akt, glycogen synthase kinase 3-beta (GSK-3β), and reduced expression of β-catenin in BIU-87 as well as EJ cells by Western blot and Immunofluorescence analysis. In addition, down-regulation of ILK also could increase expression of Ribonuclease inhibitor (RI), an important acidic cytoplasmic protein with many functions. BALB/C nude mice injected with the BIU-87 cells transfected ILK siRNA showed a significant inhibition of the tumor growth with lighter tumor weight, lower microvessels density and higher apoptosis rate than those in the other two control groups. In conclusion, these results suggest that ILK might be involved in the development of bladder cancer, and could be served as a novel potential therapy target for human bladder cancer. Our study may be of biological and clinical importance.
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Affiliation(s)
- Juan Gao
- Department of Cell Biology and Genetics, Chongqing Medical University, 1 Yixueyuan Road, Yuzhong District, Chongqing 400016, PR China
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Clayton S, Mousa SA. Therapeutics formulated to target cancer stem cells: Is it in our future? Cancer Cell Int 2011; 11:7. [PMID: 21439058 PMCID: PMC3073868 DOI: 10.1186/1475-2867-11-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Accepted: 03/25/2011] [Indexed: 01/22/2023] Open
Abstract
With the political, social and financial drives for cancer research, many advances have been made in the treatment of many different cancer types. For example, given the increase in awareness, early detection, and treatment of breast and prostate cancers, we have seen substantial increases in survival rates. Unfortunately there are some realms of cancer that have not seen these substantial advancements, largely due to their rapid progression and the inability to specifically target therapy.The hypothesis that cancers arise from a small population of cells, called cancer stem cells (CSCs), is gaining more popularity amongst researchers. There are, however, still many skeptics who bring into question the validity of this theory. Many skeptics believe that there is not a specific subset of cells that originate with these characteristics, but that they develop certain features over time making them more resistant to conventional therapy. It is theorized that many of the relapses occurring after remission are due to our inability to destroy the self-renewing CSCs. This central idea, that CSCs are biologically different from all other cancer cells, has directed research towards the development of therapy to target CSCs directly. The major dilemma in targeting therapy in myeloproliferative disorders, malignancies of the central nervous system or malignancies in general, is the inability to target CSCs as opposed to normal stem cells. However, with the recent advances in the identifications of unique molecular signatures for CSCs along with ongoing clinical trials targeting CSCs, it is possible to use targeted nanotechnology-based strategies in the management of different types of cancers.
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Affiliation(s)
- Stephanie Clayton
- The Pharmaceutical Research Institute at Albany College of Pharmacy and Health Sciences, One Discovery Drive, Rensselaer, NY, 12144, USA.
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