Biotecnologia e Biomateriais

Abstrato

The Tripeptide, GHK, Induces Programmed Cell Death in SH-SY5Y Neuroblastoma Cells

Luay E. Matalka, Ashley Ford and M. Tino Unlap

GHK-Cu is a tripeptide that is found in plasma and increases fibroblast proliferation and is widely used in wound healing creams. Studies show that GHK-Cu stimulates the level of p63, a member of the antitumor suppressor family which includes p53 and p73. Because of its effect on p63, we tested the hypothesis that GHK induces apoptosis in neuroblastoma cells, SH-SY5Y, and that modification of GHK by polyethylene glycol (PEG) conjugation, PEGylation, potentiates its effects. Initial studies on NIH-3T3 fibroblasts and U937 histiocytic lymphoma cells show that GHK-Cu and GHK-PEG stimulate fibroblast proliferation while attenuating U937 cell proliferation. SH-SY5Y cells were treated with GHK or GHK-PEG at 1 and 10 nM for 24 hours followed by cell proliferation, cell viability, cell cytotoxicity and apoptosis assays. Our results showed that 24 hour GHK treatment elevated apoptosis by 1.8 ± 0.17 and 3.3 ± 0.15 fold at 1 and 10 nM, respectively. GHK-PEG treatment, on the other hand, stimulated apoptosis by 3.2 ± 0.80 and 4.9 ± 0.9 fold at 1 and 10 nM, respectively. The treatments, while having no effects on cell cytotoxicity, reduced neuroblastoma cell viability and cell proliferation. Therefore, GHK induces apoptosis in neuroblastoma cells, an affect which was potentiated by PEGylation.