Synthesis and identification of RGD-modified tumstatin peptide 19 and its inhibitory effect on proliferation, migration, and invasion of liver cancer SK-Hep-1 cells.

Objective: To analyze the effects of arginine-glycine-aspartic acid (RGD) modification on anti-hepatocarcinoma activity of tumstatin peptide 19 (T-19) and to comparatively analyze the effects of tumor suppressor peptide 19 (T-19) and RGD modified-T-19 (RGD-T-19) on the proliferation, invasion, migration of on liver cancer SK-Hep-1 cells. Methods: T-19 and RGD-T-19 were synthesized by Fmoc solid-phase method and separated and identified using high-performance liquid chromatography and mass spectrometry. SK-Hep-1 cells were routinely cultured and treated with 0, 50, 100, 150, 200, and 250 mg/mL of T-19 and RGD-T-19, respectively. The cells were divided into control group (0 mg/mL), 50 mg/mL group, 100 mg/mL group, 150 mg/mL group, 200 mg/mL group, and 250 mg/mL group. CCK-8 assay and clone formation test were used to detect the effects of T-19 and RGD-T-19 on the viability and proliferation of SK-hep-1 cells. The invasion and migration of SK-Hep-1 cells were observed by scratch and Transwell test. The mRNA expression of cellular matrix metalloproteinases MMP-2 and MMP-9 was detected by qPCR. The protein expression of COX-2, MMP-2, MMP-9, TIMP-1, and TIMP-2 was detected by Western blot. Results: The synthesized T-19 and RGD-T-19 were identified to be of high purity by mass spectroscopy. Both T-19 and RGD-T-19 significantly inhibited the proliferation, migration, and invasion abilities of SK-Hep-1 cells, suppressed the protein expression of COX-2 and both the mRNA and protein expression of MMP-2, and MMP-9, but promoted the protein expression of TIMP-1 and TIMP-2 (P < 0.05, P < 0.01, P < 0.001). Notably, the inhibitory or promoting effects of RGD-T-19 were significantly stronger than those of T-19 (P < 0.05). Conclusion: T-19 and RGD-T-19 synthesized by Fmoc solid-phase method were highly pure and eligible. Both T-19 and RGD-T-19 can inhibit the proliferation, invasion, and migration of SK-Hep-1 cells, with better effects of RGD-T-19 than T-19. [ABSTRACT FROM AUTHOR]