Biomedical Engineering Reference
In-Depth Information
A.
Phage-display peptide library to screen
organ specific peptides
Phage-display peptide library to screen
organ specific peptides
B.
Tumor cell binding to specific organs
Through
blood
vessels
Through
blood
vessels
Through
blood
vessels
Through
blood
vessels
Lung
Lung
Lung
Lung
Brain
Brain
Brain
Brain
Fig. 2
A schematic representation demonstrating the similarities between organ-specii c
homing of phages and malignant cells. A. Unique peptides displayed on the surface of phages have
ai nity for receptors expressed on specii c organs and help the phages to home to that organ. B.
Similarly, receptors expressed on the surface of malignant cells help them home to organ-specii c
microenvironment during metastasis.
Bioinformatics and Phage-display Assay
h e screened peptide sequences from a phage-display assay can be used to
identify CAMs that have residues in their conserved ligand-binding regions. At er
successful identii cation of the CAMs expressed on the surface of the tumor cells,
they can be targeted using the specii c peptides. Bioinformatics tools and databases
can help achieve the CAM identii cation process (Sadanandam
et al
. 2007). At
present, phage-display technology based CAM identii cation can be divided into
display peptide sequences, (2) screening the tumor-associated proteins that have
these peptides in their ligand-binding regions using sequence database searches,
(3) understanding the structural signii cance of the peptide sequence at the ligand-
binding regions of tumor-associated CAMs, and (4) screening the gene expression
of tumor-associated CAMs to understand their role in cancer. In this section, we
review each of these steps in detail.
Consensus-binding Motifs
One can detect phage-displayed peptides as those that occur much more frequently
than one would expect by random chance. Several reports have demonstrated that
