TMTP1, a 5-amino
acid peptide NVVRQ, obtained by using the flagella
peptide library screening in our previous studies, can be used for the labeling of malignant in situ and metastatic lesions, and even micro-
metastases. In this study, TMTP1 was assessed for its ability to specifically target the malignant hematopoietic cells and metastatic lesions of
hematological malignancies. FITC-TMTP1 was chemically synthesized. Immunofluorescence assay and competitive test were carried out to determine the specific binding capacity of TMTPl to hematological malignant cell lines, including HL60, k562, SHI-1, Jurkat, Raji, El-4 and umbilical cord blood mononuclear cells. Mononuclear cells were isolated from the bone marrow of healthy subjects and patients with
chronic myeloid leukemia. Then the cells were co-cultured with TMTP1 or scrambled
peptides and the binding and affinity of
TMTP1 peptide to the primary cells of
hematological malignancies were flow cytometrically analyzed. The binding specificity of TMTP1 to target
hematological malignancies was measured in vivo by
intravenous injection of
FITC-conjugated TMTP1 into El-4
lymphoma-bearing mice. The results showed that TMTP1 specifically bound to the cells of a series of
hematological malignancies, including HL60, k562, Jurkat, Raji, El-4 and
chronic myeloid leukemia primary cells but not to bone marrow mononuclear cells from healthy subjects. By contrast, TMTP1 could bind to the metastatic foci of
lymphoma originating from the EL-4 cell line while the scrambled
peptide failed to do so. Moreover, the occult
metastases could be identified, with high specificity, by detecting FITC-TMTP1. We are led to conclude that TMTP1, as a novel
tumor-homing
peptide, can serve as a marker for primary malignant and metastatic lesions for the early diagnosis of hematological malignances and a carrier of anticancer drugs for
cancer treatment.