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Kural MH, Djakbarova U, Cakir B, Tanaka Y, Chan ET, Arteaga Muniz VI, Madraki Y, Qian H, Park J, Sewanan LR, Park IH, Niklason LE, Kural C. Mechano-inhibition of endocytosis sensitizes cancer cells to Fas-induced Apoptosis. Cell Death Dis 2024; 15:440. [PMID: 38909035 PMCID: PMC11193792 DOI: 10.1038/s41419-024-06822-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 06/24/2024]
Abstract
The transmembrane death receptor Fas transduces apoptotic signals upon binding its ligand, FasL. Although Fas is highly expressed in cancer cells, insufficient cell surface Fas expression desensitizes cancer cells to Fas-induced apoptosis. Here, we show that the increase in Fas microaggregate formation on the plasma membrane in response to the inhibition of endocytosis sensitizes cancer cells to Fas-induced apoptosis. We used a clinically accessible Rho-kinase inhibitor, fasudil, that reduces endocytosis dynamics by increasing plasma membrane tension. In combination with exogenous soluble FasL (sFasL), fasudil promoted cancer cell apoptosis, but this collaborative effect was substantially weaker in nonmalignant cells. The combination of sFasL and fasudil prevented glioblastoma cell growth in embryonic stem cell-derived brain organoids and induced tumor regression in a xenograft mouse model. Our results demonstrate that sFasL has strong potential for apoptosis-directed cancer therapy when Fas microaggregate formation is augmented by mechano-inhibition of endocytosis.
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Affiliation(s)
- Mehmet H Kural
- Department of Anesthesiology, School of Medicine, Yale University, New Haven, CT, 06519, USA.
- Humacyte Inc., Durham, NC, 27213, USA.
| | | | - Bilal Cakir
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Yoshiaki Tanaka
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, 06519, USA
- Department of Medicine, Maisonneuve-Rosemont Hospital Research Center, University of Montreal, Montreal, QC, H1T 2M4, Canada
| | - Emily T Chan
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
- Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
| | | | - Yasaman Madraki
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
| | - Hong Qian
- Department of Anesthesiology, School of Medicine, Yale University, New Haven, CT, 06519, USA
- Humacyte Inc., Durham, NC, 27213, USA
| | - Jinkyu Park
- Yale Cardiovascular Research Center, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, 06519, USA
| | - Lorenzo R Sewanan
- Department of Internal Medicine, Columbia University, New York, NY, 10032, USA
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Laura E Niklason
- Department of Anesthesiology, School of Medicine, Yale University, New Haven, CT, 06519, USA.
- Humacyte Inc., Durham, NC, 27213, USA.
| | - Comert Kural
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA.
- Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, 43210, USA.
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2
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Pham TD. Fuzzy Recurrence Exponents of Subcellular-Nanostructure Dynamics in Time-lapse Confocal Imaging. IEEE Trans Nanobioscience 2021; 20:497-506. [PMID: 34398761 DOI: 10.1109/tnb.2021.3105533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Studying the dynamics of nanostructures in the intracellular space is important because it allows gaining insights into the mechanism of complex biological functions of organelles. Understanding such dynamical processes can contribute to the development of nanomedicine for the diagnosis and treatment of many diseases caused by the interaction of multiple genes and environmental factors. Here a quantitative measure of spatial-temporal dynamics of nanostructures within a cell line in the context of nonlinear dynamics is introduced, where early endosomes, late endosomes, and lysosomes recorded by time-lapse confocal imaging are examined. The mathematical derivation of the proposed technique is based on the concept of recurrence dynamics and sequential rate of change over time. The quantification introduced as fuzzy recurrence exponents can be generalized for characterizing the dynamics of experimental evolutions in other nanostructures of living cells captured under the optical microscope.
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3
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Taskaeva I, Bgatova N, Gogaeva I. Lithium effects on vesicular trafficking in hepatocellular carcinoma cells. Ultrastruct Pathol 2019; 43:301-311. [PMID: 31826700 DOI: 10.1080/01913123.2019.1701167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most commonly malignant tumors worldwide, characterized by the presence of many heterogeneous molecular cell events that contribute to tumor growth and progression. Endocytic processes are intimately involved in various pathological conditions, including cancer, since they interface with various cellular signaling programs. The ability of lithium to induce cell death and autophagy and affect cell proliferation and intracellular signaling has been shown in various experimental tumor models. The aim of this study was to evaluate the effects of lithium on vesicular transport in hepatocellular carcinoma cells. Using transmission electron microscopy we have characterized the endocytic apparatus in hepatocellular carcinoma-29 (HCC-29) cells in vivo and detailed changes in endocytotic vesicles after 20 mM lithium carbonate administration. Immunofluorescent analysis was used to quantify cells positive for EEA1-positive early endosomes, Rab11-positive recycling endosomes and Rab7-positive late endosomes. Lithium treatment caused an increase in EEA1- and Rab11-positive structures and a decrease in Rab7-positive vesicles. Thus, lithium affects diverse endocytic pathways in HCC-29 cells which may modulate growth and development of hepatocellular carcinoma.
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Affiliation(s)
- Iuliia Taskaeva
- Laboratory of Ultrastructural Research, Research Institute of Clinical and Experimental Lymphology - Branch of the Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Laboratory of Boron-Neutron Capture Therapy, Department of Physics, Novosibirsk State University, Novosibirsk, Russia
| | - Nataliya Bgatova
- Laboratory of Ultrastructural Research, Research Institute of Clinical and Experimental Lymphology - Branch of the Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Izabella Gogaeva
- Laboratory of Ultrastructural Research, Research Institute of Clinical and Experimental Lymphology - Branch of the Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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4
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Ferri G, Digiacomo L, D'Autilia F, Durso W, Caracciolo G, Cardarelli F. Time-lapse confocal imaging datasets to assess structural and dynamic properties of subcellular nanostructures. Sci Data 2018; 5:180191. [PMID: 30226484 PMCID: PMC6142892 DOI: 10.1038/sdata.2018.191] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/23/2018] [Indexed: 01/14/2023] Open
Abstract
Time-lapse optical microscopy datasets from living cells can potentially afford an enormous amount of quantitative information on the relevant structural and dynamic properties of sub-cellular organelles/structures, provided that both the spatial and temporal dimensions are properly sampled during the experiment. Here we provide exemplary live-cell, time-lapse confocal imaging datasets corresponding to three sub-cellular structures of the endo-lysosomal pathway, i.e. early endosomes, late endosomes and lysosomes, along with detailed guidelines to produce analogous experiments. Validation of the datasets is conducted by means of established analytical tools to extract the structural and dynamic properties at the sub-cellular scale, such as Single Particle Tracking (SPT) and imaging derived Mean Square Displacement (iMSD) analyses. In our aim, the present work would help other researchers in the field to reuse the provided datasets for their own scopes, and to combine their creative approaches/analyses to similar acquisitions.
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Affiliation(s)
- Gianmarco Ferri
- NEST-Scuola Normale Superiore, Istituto Nanoscienze-CNR (CNR-NANO), 56127 Pisa, Italy.,Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy
| | - Luca Digiacomo
- Department of Molecular Medicine, "La Sapienza" University of Rome, 00161 Rome, Italy
| | - Francesca D'Autilia
- Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
| | - William Durso
- Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
| | - Giulio Caracciolo
- Department of Molecular Medicine, "La Sapienza" University of Rome, 00161 Rome, Italy
| | - Francesco Cardarelli
- NEST-Scuola Normale Superiore, Istituto Nanoscienze-CNR (CNR-NANO), 56127 Pisa, Italy
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5
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Dynamic fingerprinting of sub-cellular nanostructures by image mean square displacement analysis. Sci Rep 2017; 7:14836. [PMID: 29093485 PMCID: PMC5665924 DOI: 10.1038/s41598-017-13865-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/27/2017] [Indexed: 11/08/2022] Open
Abstract
Here we provide demonstration that image mean square displacement (iMSD) analysis is a fast and robust platform to address living matter dynamic organization at the level of sub-cellular nanostructures (e.g. endocytic vesicles, early/late endosomes, lysosomes), with no a-priori knowledge of the system, and no need to extract single trajectories. From each iMSD, a unique triplet of average parameters (namely: diffusivity, anomalous coefficient, size) are extracted and represented in a 3D parametric space, where clustering of single-cell points readily defines the structure "dynamic fingerprint", at the whole-cell-population level. We demonstrate that different sub-cellular structures segregate into separate regions of the parametric space. The potency of this approach is further proved through application to two exemplary, still controversial, cases: i) the intracellular trafficking of lysosomes, comprising both free diffusion and directed motion along cytoskeletal components, and ii) the evolving dynamic properties of macropinosomes, passing from early to late stages of intracellular trafficking. We strongly believe this strategy may represent a flexible, multiplexed platform to address the dynamic properties of living matter at the sub-cellular level, both in the physiological and pathological state.
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Liu X, Rothe K, Yen R, Fruhstorfer C, Maetzig T, Chen M, Forrest DL, Humphries RK, Jiang X. A novel AHI-1-BCR-ABL-DNM2 complex regulates leukemic properties of primitive CML cells through enhanced cellular endocytosis and ROS-mediated autophagy. Leukemia 2017; 31:2376-2387. [PMID: 28366933 PMCID: PMC5668499 DOI: 10.1038/leu.2017.108] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 03/17/2017] [Accepted: 03/22/2017] [Indexed: 02/07/2023]
Abstract
Tyrosine kinase inhibitor (TKI) therapies induce clinical remission with remarkable effects on chronic myeloid leukemia (CML). However, very few TKIs completely eradicate the leukemic clone and persistence of leukemic stem cells (LSCs) remains challenging, warranting new, distinct targets for improved treatments. We demonstrated that the scaffold protein AHI-1 is highly deregulated in LSCs and interacts with multiple proteins, including Dynamin-2 (DNM2), to mediate TKI-resistance of LSCs. We have now demonstrated that the SH3 domain of AHI-1 and the proline rich domain of DNM2 are mainly responsible for this interaction. DNM2 expression was significantly increased in CML stem/progenitor cells; knockdown of DNM2 greatly impaired their survival and sensitized them to TKI treatments. Importantly, a new AHI-1-BCR-ABL-DNM2 protein complex was uncovered, which regulates leukemic properties of these cells through a unique mechanism of cellular endocytosis and ROS-mediated autophagy. Thus, targeting this complex may facilitate eradication of LSCs for curative therapies.
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Affiliation(s)
- X Liu
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - K Rothe
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - R Yen
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - C Fruhstorfer
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - T Maetzig
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - M Chen
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - D L Forrest
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,Leukemia/BMT Program of British Columbia, Vancouver, BC, Canada
| | - R K Humphries
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - X Jiang
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
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7
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Zou MX, Huang W, Wang XB, Li J, Lv GH, Wang B, Deng YW. Reduced expression of miRNA-1237-3p associated with poor survival of spinal chordoma patients. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2015; 24:1738-46. [DOI: 10.1007/s00586-015-3927-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 04/01/2015] [Accepted: 04/01/2015] [Indexed: 01/23/2023]
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8
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Ivyna Bong PN, Ng CC, Lam KY, Megat Baharuddin PJN, Chang KM, Zakaria Z. Identification of novel pathogenic copy number aberrations in multiple myeloma: the Malaysian context. Mol Cytogenet 2014; 7:24. [PMID: 24690091 PMCID: PMC4021726 DOI: 10.1186/1755-8166-7-24] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 03/24/2014] [Indexed: 02/07/2023] Open
Abstract
Background Multiple myeloma is an incurable disease. Little is known about the genetic and molecular mechanisms governing the pathogenesis of multiple myeloma. The risk of multiple myeloma predispositions varies among different ethnicities. More than 50% of myeloma cases showed normal karyotypes with conventional cytogenetic analysis due to the low mitotic activity and content of plasma cells in the bone marrow. In the present study, high resolution array comparative genomic hybridization technique was used to identify copy number aberrations in 63 multiple myeloma patients of Malaysia. Results Copy number aberrations were identified in 100% of patients analyzed (n = 63). Common chromosomal gains were detected at regions 1q, 2q, 3p, 3q, 4q, 5q, 6q, 8q, 9q, 10q, 11q, 13q, 14q, 15q, 21q and Xq while common chromosomal losses were identified at regions 3q and 14q. There were a total of 25 and 5 genes localized within the regions of copy number gains and losses, respectively (>30% penetrance). The LYST, CLK1, ACSL1 and NFKBIA are genes localized within the copy number aberration regions and they represent novel information that has never been previously described in multiple myeloma patients. Conclusions In general, due to the differences in genetic background, dietary and lifestyle practices of Malaysian compared to the Caucasian population, these chromosomal alterations might be unique for Asian MM patients. Genes identified in this study could be potential molecular therapeutic targets for the treatment and management of patients with multiple myeloma.
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Affiliation(s)
- Pau Ni Ivyna Bong
- Hematology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur, Malaysia.
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9
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Shaughnessy R, Retamal C, Oyanadel C, Norambuena A, López A, Bravo-Zehnder M, Montecino FJ, Metz C, Soza A, González A. Epidermal growth factor receptor endocytic traffic perturbation by phosphatidate phosphohydrolase inhibition: new strategy against cancer. FEBS J 2014; 281:2172-89. [PMID: 24597955 DOI: 10.1111/febs.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 02/02/2014] [Accepted: 02/26/2014] [Indexed: 01/11/2023]
Abstract
Epidermal growth factor receptor (EGFR) exaggerated (oncogenic) function is currently targeted in cancer treatment with drugs that block receptor ligand binding or tyrosine kinase activity. Because endocytic trafficking is a crucial regulator of EGFR function, its pharmacological perturbation might provide a new anti-tumoral strategy. Inhibition of phosphatidic acid (PA) phosphohydrolase (PAP) activity has been shown to trigger PA signaling towards type 4 phosphodiesterase (PDE4) activation and protein kinase A inhibition, leading to internalization of empty/inactive EGFR. Here, we used propranolol, its l- and d- isomers and desipramine as PAP inhibitors to further explore the effects of PAP inhibition on EGFR endocytic trafficking and its consequences on EGFR-dependent cancer cell line models. PAP inhibition not only made EGFR inaccessible to stimuli but also prolonged the signaling lifetime of ligand-activated EGFR in recycling endosomes. Strikingly, such endocytic perturbations applied in acute/intermittent PAP inhibitor treatments selectively impaired cell proliferation/viability sustained by an exaggerated EGFR function. Phospholipase D inhibition with FIPI (5-fluoro-2-indolyl des-chlorohalopemide) and PDE4 inhibition with rolipram abrogated both the anti-tumoral and endocytic effects of PAP inhibition. Prolonged treatments with a low concentration of PAP inhibitors, although without detectable endocytic effects, still counteracted cell proliferation, induced apoptosis and decreased anchorage-independent growth of cells bearing EGFR oncogenic influences. Overall, our results show that PAP inhibitors can counteract EGFR oncogenic traits, including receptor overexpression or activating mutations resistant to current tyrosine kinase inhibitors, perturbing EGFR endocytic trafficking and perhaps other as yet unknown processes, depending on treatment conditions. This puts PAP activity forward as a new suitable target against EGFR-driven malignancy.
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Affiliation(s)
- Ronan Shaughnessy
- Departamento de Inmunología Clínica y Reumatología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile; Centro de Envejecimiento y Regeneración, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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10
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Otero C, Linke M, Sanchez P, González A, Schaap IAT. Propranolol restricts the mobility of single EGF-receptors on the cell surface before their internalization. PLoS One 2013; 8:e83086. [PMID: 24349439 PMCID: PMC3857351 DOI: 10.1371/journal.pone.0083086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 10/30/2013] [Indexed: 12/02/2022] Open
Abstract
The epidermal growth factor receptor is involved in morphogenesis, proliferation and cell migration. Its up-regulation during tumorigenesis makes this receptor an interesting therapeutic target. In the absence of the ligand, the inhibition of phosphatidic acid phosphohydrolase activity by propranolol treatment leads to internalization of empty/inactive receptors. The molecular events involved in this endocytosis remain unknown. Here, we quantified the effects of propranolol on the mobility of single quantum-dot labelled receptors before the actual internalization took place. The single receptors showed a clear stop-and-go motion; their diffusive tracks were continuously interrupted by sub-second stalling events, presumably caused by transient clustering. In the presence of propranolol we found that: i) the diffusion rate reduced by 22 %, which indicates an increase in drag of the receptor. Atomic force microscopy measurements did not show an increase of the effective membrane tension, such that clustering of the receptor remains the likely mechanism for its reduced mobility. ii) The receptor got frequently stalled for longer periods of multiple seconds, which may signal the first step of the internalization process.
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Affiliation(s)
- Carolina Otero
- Center for Integrative Medicine and Innovative Science (CIMIS), Universidad Andres Bello, Santiago, Chile ; Centro para el Desarrollo de la Nanociencia y Nanotecnologia, Santiago, Chile
| | - Max Linke
- III. Physikalisches Institut, Faculty of Physics, Georg-August Universität, Göttingen, Germany
| | - Paula Sanchez
- III. Physikalisches Institut, Faculty of Physics, Georg-August Universität, Göttingen, Germany ; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Alfonso González
- Departamento de Inmunología Clínica y Reumatología, Facultad de Medicina and Centro de Envejecimiento y Regeneración, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Iwan A T Schaap
- III. Physikalisches Institut, Faculty of Physics, Georg-August Universität, Göttingen, Germany ; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
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The PICALM protein plays a key role in iron homeostasis and cell proliferation. PLoS One 2012; 7:e44252. [PMID: 22952941 PMCID: PMC3431333 DOI: 10.1371/journal.pone.0044252] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/31/2012] [Indexed: 01/16/2023] Open
Abstract
The ubiquitously expressed phosphatidylinositol binding clathrin assembly (PICALM) protein associates with the plasma membrane, binds clathrin, and plays a role in clathrin-mediated endocytosis. Alterations of the human PICALM gene are present in aggressive hematopoietic malignancies, and genome-wide association studies have recently linked the PICALM locus to late-onset Alzheimer's disease. Inactivating and hypomorphic Picalm mutations in mice cause different degrees of severity of anemia, abnormal iron metabolism, growth retardation and shortened lifespan. To understand PICALM’s function, we studied the consequences of PICALM overexpression and characterized PICALM-deficient cells derived from mutant fit1 mice. Our results identify a role for PICALM in transferrin receptor (TfR) internalization and demonstrate that the C-terminal PICALM residues are critical for its association with clathrin and for the inhibitory effect of PICALM overexpression on TfR internalization. Murine embryonic fibroblasts (MEFs) that are deficient in PICALM display several characteristics of iron deficiency (increased surface TfR expression, decreased intracellular iron levels, and reduced cellular proliferation), all of which are rescued by retroviral PICALM expression. The proliferation defect of cells that lack PICALM results, at least in part, from insufficient iron uptake, since it can be corrected by iron supplementation. Moreover, PICALM-deficient cells are particularly sensitive to iron chelation. Taken together, these data reveal that PICALM plays a critical role in iron homeostasis, and offer new perspectives into the pathogenesis of PICALM-associated diseases.
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12
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Di Fiore PP. Endocytosis, signaling and cancer, much more than meets the eye. Preface. Mol Oncol 2009; 3:273-9. [PMID: 19628439 DOI: 10.1016/j.molonc.2009.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 06/12/2009] [Indexed: 11/24/2022] Open
Affiliation(s)
- Pier Paolo Di Fiore
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare at IFOM-IEO Campus, 20139 Milan, Italy.
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