OBJECTIVETo study the effect of the synthetic peptide RGDSY-CTTHWGFTLC on the biological behavior of breast cancer MCF-7 cells in vitro.

METHODSMCF-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.

RESULTSIncubation of the cells with 50, 100 and 200 µg/ml of RGDSY-CTT caused a significant concentration- dependent 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).

CONCLUSIONSRGDSY-CTT can inhibit cell invasion, suppress adhesion and proliferation, and induce apoptosis in MCF-7 cells.