Tumor homing peptides

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Tumor homing peptides

• Lixia Wei

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How do USPS people deal with tons of letters and
packages and send them to different locations
efficiently?
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Zip Code and Address
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Cancer and its microenvironment
Blood supply is very important for cancer growth
and metastasis
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• Can we target cancer cell or its microenvironment
  by
• any zip code and address in cancer like our home?
• Activated endothelial cells and pericytes in the
  neovasculature express molecules (tumor maker)
  that are not expressed or are expressed at much
  lower levels in normal vessels

• Lots of biological markers are overexpressed in
  cancer
• VEGF ( Vascular Endothelial Growth Factor) and
  other growth factors
• Integrins a?ß3 ,a?ß5
• Peptidases/proteases Aminopeptidase N, MMP
  family
• Membrane proteins with unknown functions
• Do we have any carrier to deliver drug or image
  particles to cancer addresses?

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• Phage Display
• Phage display is a system in which a protein is
  displayed on the surface
• of a phage as a fusion with one of the phage
  coated proteins.
• Phage display technique is a test to screen for
  protein interaction by
• integrating multiple genes from a gene bank
  into phages

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Advantages of selection of tumor target peptide
in vivo by phage display technique

• peptides displayed on the phage particles can be
  identified and tested functionally and must
  overcome natural mechanisms of degradation
• peptides recognizing unspecific molecules are
  depleted from circulation
• in vivo selection is able to identify receptors
  expressed selectively on tumor endothelium

These peptides can serve as molecular targets for
the development of diagnostic techniques and
targeted therapies.
Tumor Homing peptide
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1. Homing peptides target to tumor
vasculature Endothelial cells in the angiogenic
vessels express several proteins that are absent
or barely detectable in established blood vessel

• The first motif is NGR (Asn-Gly-Arg)
• Phage displayed peptide CNGRCVSGCAGRC
• was injected into the tail vein of mice
  bearing
• MDA-MB-435 derived tumors and recovered

C) NGR binds aminopeptidase N
Mice bearing breast cancer( MDA-MB-435)
Wadih Arap et al. Science 1998 ,Vol (279) Renata
et al. Cancer Research 2000, Vol (60)
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• The second motif is GSL (Gly-Ser-Leu)
• Recovery of CGSLVRC phage and
• inhibition of tumor homing by the
• soluble peptide CGSLVRC

• The third motif is RGD (Arg-Gly-Asp)
• Phage displayed peptide CDCRGDCFC
• (RGD-4C) was injected into the tail vein
• of tumor bearing mice and recovered
• RGD motif binds selectively to integrins
• which are overexpressed on endothelial
• cell surface in the cancer and facilitate
• cancer cell migration

Wadih Arap et al. Science 1998 ,Vol (279) Renata
et al. Cancer Research 2000, Vol (60)
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NGR motif peptide targets to the tumor
vasculature
5 mins after injection
24 hours after injection
control
Wadih Arap et al. Science 1998 ,Vol (279)
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A fragment of the HMGN2 protein (F3 peptide)

• High mobility group protein 2 is highly
  conserved nucleosomal protein
• HMGN2 involves in unfolding higher-order
  chromatin structure and facilitating the
  transcriptional
• activation of mammalian genes

Tumor
Brain
Mice bearing myeloid leukemia tumor (HL-60)
Kimmo porkka et al. PNAS 2002, Vol 99
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Nuclear localization of F3 peptide
HL-60 with F3 HL-60 with control peptide
F3 peptide colocalized with tumor vascular and
tumor cells
Kimmo porkka et al. PNAS 2002, Vol 99
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Peptide CGKRK and CDTRL
Mice bearing epidermal squamous cell cancer
(K14-HPV-16)
Peptide CGKRK and CDTRL colocalized with vascular
marker (MECA32) in tumor
Jason A. Hoffman et al. Cancer Cell 2003, Vol 4
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2. Homing peptide targets to tumor lymphatic
vessels
Tumor lymphatics also carry specific markers
Peptide LyP-1(CCGNKRTRGC) home to tumor
lymphatics and tumor cells
Mice bearing MDA-MB-435 breast cancer
Peptide LyP-1 was mostly recovered from tumor
sites and internalized by tumor cells
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LyP-1 (green) Blood vessel (red)
LyP-1 (green) Lymphatic vessel (red
presents three different markers)
Peptide LyP-1 binds to tumor lymphatics and tumor
cells in MDA-MB-435
Pirjo Lakkonen et al. Nature Medicine 2002, Vol 8
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3. Homing peptide targets to tumor cells
Affibody (Z HER 24, 58aa) targets to epidermal
growth factor receptor 2 (HER2/neu)
Affibody binds to SKBR-3 breast cancer cells with
non-competitive manner to Trastuzumab
M.Wilkman et al Protein Engineering, Design
Selection 2004, Vol 17
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Mice bearing SKOV-3 (breast cancer) tumor
Affibody labeled with 125I was imaged by gamma
camera after injection 6 hours and 8 hours
Ann-Charlott steffen et al. Eur J Nucl Med Mol
Imaging 2006, Vol 33
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Summary of tumor homing peptides
Affibody
31 aa 58aa
HER2
Tumor cells
Cell surface/ cytoplasmic
Erkki Ruoslahti Druge Discoery Today 2002, Vol 7
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Application of tumor homing peptides
1. Diagnose cancer
F3 peptide LyP-1 peptide
Nanoparticle coated homing peptides can target
tumor sites
Maria E.Akerman et al. PNAS 2002, Vol.99
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2. Deliver drugs to treat cancer

• Doxorubicin (Dox) is one of the most frequently
  used anticancer drugs and
• one of a few chemotherapeutic agents known to
  have antiangiogenic activity
• Dox was conjugated with RGD-4C and NGR motifs to
  treat mice bearing with
• MDA-MB-435

Dox-RGD treated mice bearing tumor (MDA-MB-435)
Wadih Arap et al. Science 1998 ,Vol (279)
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Dox-CNGRC treated mice bearing tumor (MDA-MB-435)
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• Conclusions
• Phage display is very powerful technique which
  can be used to identify
• homing peptide to target tumor specific
  markers.
• Tumor cell, vasculature and lymphatics have their
  own zip codes and
• addresses.
• Homing peptide can be widely used in diagnostic
  and therapeutic cancers
• by conjugating them with anticancer drugs
  or imaging particles.
• In the future, homing peptide drugs may be the
  most promising methods
• to treat kinds of human diseases, not only
  cancers.