Phage Ligands for Identification of Mesenchymal-Like Breast Cancer Cells and Cancer-Associated Fibroblasts

Abstract

Epithelial to mesenchymal transition (EMT) is believed to be crucial for primary tumors to escape their original residence and invade and metastasize. To properly define EMT, there is a need for ligands that can identify this phenomenon in tumor tissue and invivo. A phage-display selection screening was performed to select novel binding phage peptides for identification of EMT in breast cancer. Epithelial breast cancer cell line, MCF-7 was transformed to mesenchymal phenotype by TGF-β treatment and was used for selection. Breast fibroblasts were used for subtractive depletion and breast cancer metastatic cell lines MDA-MB-231, T47D-shNMI were used for specificity assay. The binding peptides were identified, and their binding capacities were confirmed by phage capture assay, phage-based ELISA, immunofluorescence microscopy. The phage peptide bearing the 7-amino acid sequence, LGLRGSL, demonstrated selective binding to EMT phenotypic cells (MCF-7/TGF-β and MDA-MB-231) as compared to epithelial subtype, MCF-7, T47D and breast fibroblasts (Hs578T). The selected phage was also able to identify metastatic breast cancer tumor in breast cancer tissue microarray (TMA). These studies suggest that the selected phage peptide LGLRGSL identified by phage-display library, showed significant ability to bind to mesenchymal-like breast cancer cells/ tissues and can serve as a novel probe/ligand for metastatic breast cancer diagnostic and imaging.

Determination and characterisation of the surface charge properties of the bacteriophage M13 to assist bio-nanoengineering

“…Chemical and genetic modications of M13 are largely exploited in the eld of bio-nanoengineering for the fabrication of nanostructured materials. [7][8][9] In particular, genetic modication allows the display of specic peptides that can bind a variety of molecules for the fabrication of biosensors [16][17][18] and electronic materials 19 as well as target cancerous cells, [20][21][22][23][24] bind factors to direct cell proliferation and differentiation for tissue regeneration. 25 The presence of ionisable groups in these foreign peptides can drastically change the chemical characteristics of the virus, especially when fused to the major coat protein PVIII.…”

Clinical implications of phage display technique: Digging deeper in diagnostic and therapeutic grounds.

“…Antibodies and peptides against CD271+ [57], Mrps18a [58], neuropilin-1, platelet-derived growth factor and human epidermal growth factor receptor 2 have been identified using this technique [59]. To it, cell biopanning has also been studied in this aspect [60][61][62] 6.5 Colon cancer: Hou, et al [63] reported peptide CBP-DWS, using phage display, that had an ability to bind to colon cancer cells. Bioinformatic analysis showed that this peptide binds to glypican-3 on the colon cancer cells.…”