A novel mouse CD133 binding-peptide screened by phage display inhibits cancer cell motility in vitro.
Increased expression of CD133 (Prominin-1), an important cancer stem cell-associated marker, has been observed in the cancer stem cells of a variety of human and mouse cancers. However, no natural ligand of CD133 has yet been identified and little is known about its function. In the present study, LS-7 (amino acid sequence: LQNAPRS), a specific binding peptide targeting mouse CD133, was screened and identified for the first time by phage-displayed peptide library technology. The in vitro and in vivo affinity and specificity of LS-7 were determined, and MTT, adhesion, and migration assays were performed to evaluate the effects of LS-7 on the biological behaviors of cancer cells. To determine which signaling pathways are affected by LS-7, HMGB1, S-100A4, CXCR7, uPAR, AMFR, STAT3, and c-Met gene and protein expression were evaluated by RT-PCR and Western blot. Flow cytometry and immunofluorescence assays showed specific, high-affinity binding of the peptide to mCD133 in vitro. Confocal microscopy confirmed the co-localization of LS-7 positive cells and CD133-positive cells. Migration and wound-healing assays showed that LS-7 significantly inhibited the migration of colon and breast cancer cells in a concentration-dependent manner. In vivo experiments also confirmed the high specificity and affinity of LS-7 to mCD133. RT-PCR and Western blot showed that the expressions of only c-Met and STAT3 decreased obviously in colon and breast cancer cells exposed to LS-7. These findings may provide a novel tool for anti-motility and anti-metastasis strategies in cancer research and cancer stem cell therapy.
Department of Pathology and Key Laboratory of Molecule Tumor Pathology of Guangdong Province, Southern Medical University, Guangzhou, Guangdong, China. Sunjinmin198206@163.com
Jinmin
J
Sun
Chao
C
Zhang
Guobing
G
Liu
Hong
H
Liu
Chunping
C
Zhou
Yanxia
Y
Lu
Chang
C
Zhou
Li
L
Yuan
Xuenong
X
Li
D000071916:AC133 Antigen; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D002352:Carrier Proteins / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D014411:Neoplastic Stem Cells / Q000502:physiology; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism*; D019859:Proto-Oncogene Proteins c-met / Q000032:analysis / Q000235:genetics / Q000502:physiology; D050796:STAT3 Transcription Factor / Q000032:analysis / Q000235:genetics / Q000502:physiology
D000071916:AC133 Antigen; D015703:Antigens, CD; D002352:Carrier Proteins; D006023:Glycoproteins; C000606023:PROM1 protein, human; D019151:Peptide Library; D010455:Peptides; C000606024:Prom1 protein, mouse; D050796:STAT3 Transcription Factor; D019859:Proto-Oncogene Proteins c-met