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Endocytosis of therapeutic macromolecules in tumor cells - Mechanistic aspects of the proteoglycan receptor function

Wittrup, Anders LU (2009) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2009:104.
Abstract
Novel therapeutics to combat cancer are urgently needed. Most current pharmacological therapies have severe side effects and are seldom curative. Macromolecular drugs, and in particular nucleic acid based drugs, offer a potential remedy for this situation.



Currently, the absence of efficacious and safe methods to deliver nucleic acids to intracellular sites of action is the main impediment to the introduction of nucleic acid based therapies in the clinic. Viral delivery methods have been demonstrated to efficiently deliver nucleic acids, but also to be associated with severe, occasionally life threatening, immune reactions. Non-viral delivery methods are, so far, not sufficiently efficient for use in the clinic. Many... (More)
Novel therapeutics to combat cancer are urgently needed. Most current pharmacological therapies have severe side effects and are seldom curative. Macromolecular drugs, and in particular nucleic acid based drugs, offer a potential remedy for this situation.



Currently, the absence of efficacious and safe methods to deliver nucleic acids to intracellular sites of action is the main impediment to the introduction of nucleic acid based therapies in the clinic. Viral delivery methods have been demonstrated to efficiently deliver nucleic acids, but also to be associated with severe, occasionally life threatening, immune reactions. Non-viral delivery methods are, so far, not sufficiently efficient for use in the clinic. Many viral and virtually all non-viral macromolecular delivery methods depend on cell surface heparan sulfate proteoglycans (HS PGs) for efficient uptake, however the details of this mechanism and the exact role of the PG has been unclear.



The aim of this thesis was to clarify the role of the cell surface PG in macromolecular uptake processes. It is demonstrated that mammalian cells can internalize extracellular DNA by a pathway strictly dependent on cell surface PGs and this pathway is characterized. Secreted, positively charged, proteins and peptides including the antimicrobial peptide LL-37, are shown to facilitate the uptake process. It is also demonstrated that specific HS epitopes, present on cell surface HS PGs, are pivotal for the uptake of diverse HS binding ligands including polyamines and macromolecular antibody complexes. Finally, using a newly developed method for the isolation of endocytic vesicles, it is demonstrated that both classes of cell surface HS PGs, syndecans and glypicans, are true internalizing receptors capable of intracellular macromolecular delivery.



This thesis advances our understanding of PGs as potential targets for macromolecular delivery vehicles. This understanding will be of aid for the development of future macromolecular drugs to the benefit of the patient. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Prochiantz, Alain, Développement et Evolution du Système Nerveux
, Ecole Normale Supérieure, 
Collège de France, Paris, France
organization
publishing date
type
Thesis
publication status
published
subject
keywords
LL-37, heparan sulfate, glypican, endocytosis, drug delivery, DNA uptake, Cancer, cell penetrating peptides, non-viral gene delivery, organelle purification, proteoglycan, syndecan.
in
Lund University, Faculty of Medicine Doctoral Dissertation Series
volume
2009:104
pages
130 pages
publisher
Section of Oncology, Dept of Clinical Sciences.
defense location
GK-salen, BMC, Sölvegatan 19
defense date
2009-11-06 09:00
ISSN
1652-8220
ISBN
978-91-86253-92-9
language
English
LU publication?
yes
id
9642b90b-9c71-402a-bb14-ef9435e82c09 (old id 1488277)
date added to LUP
2009-10-20 12:02:22
date last changed
2016-09-19 08:44:45
@phdthesis{9642b90b-9c71-402a-bb14-ef9435e82c09,
  abstract     = {Novel therapeutics to combat cancer are urgently needed. Most current pharmacological therapies have severe side effects and are seldom curative. Macromolecular drugs, and in particular nucleic acid based drugs, offer a potential remedy for this situation. <br/><br>
<br/><br>
Currently, the absence of efficacious and safe methods to deliver nucleic acids to intracellular sites of action is the main impediment to the introduction of nucleic acid based therapies in the clinic. Viral delivery methods have been demonstrated to efficiently deliver nucleic acids, but also to be associated with severe, occasionally life threatening, immune reactions. Non-viral delivery methods are, so far, not sufficiently efficient for use in the clinic. Many viral and virtually all non-viral macromolecular delivery methods depend on cell surface heparan sulfate proteoglycans (HS PGs) for efficient uptake, however the details of this mechanism and the exact role of the PG has been unclear. <br/><br>
<br/><br>
The aim of this thesis was to clarify the role of the cell surface PG in macromolecular uptake processes. It is demonstrated that mammalian cells can internalize extracellular DNA by a pathway strictly dependent on cell surface PGs and this pathway is characterized. Secreted, positively charged, proteins and peptides including the antimicrobial peptide LL-37, are shown to facilitate the uptake process. It is also demonstrated that specific HS epitopes, present on cell surface HS PGs, are pivotal for the uptake of diverse HS binding ligands including polyamines and macromolecular antibody complexes. Finally, using a newly developed method for the isolation of endocytic vesicles, it is demonstrated that both classes of cell surface HS PGs, syndecans and glypicans, are true internalizing receptors capable of intracellular macromolecular delivery.<br/><br>
<br/><br>
This thesis advances our understanding of PGs as potential targets for macromolecular delivery vehicles. This understanding will be of aid for the development of future macromolecular drugs to the benefit of the patient.},
  author       = {Wittrup, Anders},
  isbn         = {978-91-86253-92-9},
  issn         = {1652-8220},
  keyword      = {LL-37,heparan sulfate,glypican,endocytosis,drug delivery,DNA uptake,Cancer,cell penetrating peptides,non-viral gene delivery,organelle purification,proteoglycan,syndecan.},
  language     = {eng},
  pages        = {130},
  publisher    = {Section of Oncology, Dept of Clinical Sciences.},
  school       = {Lund University},
  series       = {Lund University, Faculty of Medicine Doctoral Dissertation Series},
  title        = {Endocytosis of therapeutic macromolecules in tumor cells - Mechanistic aspects of the proteoglycan receptor function},
  volume       = {2009:104},
  year         = {2009},
}