Study of antitumor activity of synthetic peptide ryqlhpyr on the prostate cancer cells

Introduction . The RHAMM (hyaluronan mediated mobility receptor) is overexpressed in many types of human cancer and increased synthesis of the RHAMM usually correlates with a poor prognostic factor. In this paper, we synthesized the peptide-RYQLHPYR modulating the activity of the RHAMM and examined the therapeutic potential of this RHAMM-targeting peptide as an antitumor agent.

Objective . Study the effect of the synthetic peptide RYQLHPYR on viability, apoptosis, necrosis, caspase-3 / 7 activity, and invasion of prostate cancer cells.

Materials and methods . The peptide RYQLHPYR was prepared by solid phase synthesis. Human prostate cancer cells (PC3 m-LN4), murine embryonic fibroblasts and murine embryonic fibroblasts (RHAMM- / -). To quantify the effect of the peptide on apoptosis and cell necrosis, ELISAPLUS was used. The activity of caspase-3 / 7 was determined by the colorimetric method. Evaluation of the anti-metastatic effect of the peptide in vitro was evaluated by invasion of cells by quantitative analysis of the area of degradation of fluorescent gelatin.

Results . It was found that the peptide RYQLHPYR inhibited the growth of tumor cells PC3 m-LN4 at a concentration of 10 μg / ml (2 × 10–7 M) after 24 h by ~80 %. It was shown that the peptide stimulated the level of apoptosis in cancer cells, approximately 10-fold. It was found that the peptide increased the necrotic death of tumor cells by 2.5 times. During the research it was revealed that the peptide increased the caspase-3 / 7 activity in tumor cells by 2 times. At the same time, it was shown that RHAMM-targeting peptide had no significant effect on apoptosis and necrosis of normal cells (fibroblasts) and fibroblasts (RHAMM- / -). It was found that the peptide inhibited invasion of tumor cells by ~99.86 % at a concentration of 10 μg / ml (2 × 10–7 M).

Conclusions . The obtained results indicate that the peptide RYQLHPYR has antitumor activity and, therefore, has a therapeutic potential for the treatment of prostate cancer.