| AIM:In our previous study, we screened a phage display heptapeptide library with bFGF and isolated a high-affinity bFGF-binding peptide (referred to as P7). Herein, we further investigated the mechanism and the effects of P7 on the proliferation of colon carcinoma cells and vascular endothelial cells induced by basic fibroblast growth factor in order to evaluate the therapeutic potential of P7 using as a bFGF-binding peptide in colon cancer.METHODS:Human colon cancer cell line HT-29 and human vascular endothelial cell line HUVEC-1,2 were used as target cells for investigation. MTT method was applied to assess cell proliferation. The effect of P7 on cell cycle progress of bFGF-stimulated cells was analyzed by Flow cytometry, and the effect of P7 on bFGF-induced activation of MEK and Erkl/2 in MAPK pathway was detected by Western blotting. The whole-cell proteins were prepared from cells treated with bFGF alone or plus P7, and applied to Two Dimensional Gel Electrophoresis (2-DE). The 2-DE patterns were analyzed by using PDQuest 7.4 software. The differentially expressed protein spots were subjected to tandem time-of-flight mass spectrometry analysis. The protein levels of one of the differentially expressed proteins identified in HT-29 cells, Stathmin, were confirmed by Western blotting.RESULTS:Cell viability assay showed that the bFGF-binding peptide P7 could inhibit the proliferation of both colon cancer cells and vascular endothelial cells stimulated by bFGF. Further investigations indicated that P7 arrested the cell cycle at the G0/G1 phase of bFGF-stimulated cells, reduced the levels of phospho-Erkl/Erk2 induced by bFGF, and caused significant changes in the expression of proteins related to proliferation, cell cycle, and cancer.CONCLUSIONS:P7 inhibited proliferation of bFGF-stimulated colon cancer cells and vascular endothelial cells possibly via cell cycle arrest at the G0/G1 phase, down-regulation of signal molecular activation in MAPK pathway, and influence on the expression of some proteins related to the regulation of proliferation. The results suggested that P7 using as a bFGF-binding peptide might have therapeutic potential in colon cancer therapy via inhibition of the growth of both colon cancer cells and vascular endothelial cells. |
