Abstract: Objective To study the effect of the synthetic peptide RGDSY-CTTHWGFTLC on the biological behavior of breast
cancer MCF-7 cells in vitro. Methods MCF-7 cells were incubated with different concentrations of the synthesized peptide
RGDSY-CTTHWGFTLC (RGDSY-CTT), the positive control peptide CTTHWGFTLC (CTT), or the negative control peptide
STTHWGFTLS (STT) in fibronectin-coated 96-well plates for different time lengths, and the changes in cell adhesion,
invasiveness, proliferation, apoptosis and cell cycle were detected using Transwell chamber assay, MTT assay, and flow
cytometry. Results Incubation of the cells with 50, 100 and 200 μg/ml of RGDSY-CTT caused a significant concentrationdependent
inhibition of the cell adhesion (cell adhesion rates of 85.1%, 74.1% and 63.8%, respectively) with stronger effects
than CTT (P<0.05). At 100 and 200 μg/ml, RGDSY-CTT significantly inhibited the invasion (with inhibition rate of 41.8% and
63.9%, respectively) of MCF-7 cells with an effect similar to that by CTT (P>0.05). At 50, 100 and 200 μg/ml, RGDSY-CTT
concentration-dependently suppressed MCF-7 cell proliferation (with cell proliferation rates of 98.8% , 82.4% and 63.0% ,
respectively), and this inhibitory effect was stronger than that of CTT at 100 and 200 μg/ml (P<0.05). The results of flow
cytometry also demonstrated a stronger apoptosis-inducing effect of RGDSY-CTT (76.7%) than that in CTT, STT and the blank
control groups (P<0.05). Conclusions RGDSY-CTT can inhibit cell invasion, suppress adhesion and proliferation, and induce
apoptosis in MCF-7 cells.