Transforming Growth Factor Beta-Induced Protein (Big-H3) C-Terminal Fragment Peptide EPSIM Triggers Apoptosis in Human Osteosarcoma Cells

Transforming growth factor beta induced gene human clone 3 (BIG-H3), is an extracellular matrix protein whose expression is upregulated on treatment with TGF-beta 1. BIG-H3 protein regulates several physiological processes including cell adhesion and migration. Structural analysis of BIG-H3 revealed a secretory signal protein at the N-terminus followed by four FAS I domains and two distinct integrin binding motifs near the C-terminus: RGD and EPDIM. The C-terminal portion of the peptide is known to undergo proteolytic cleavage that provides several fragments. As various studies implicated that RGD sequence triggered apoptosis in CHO and HeLa cells, it was important to establish which proteolytic fragment triggers apoptosis in human osteosarcoma cells (Skonier et.al.,2009). A previous study conducted by this laboratory demonstrated that, truncated C-terminal fragment is necessary to induce apoptosis and when the C-terminal portion is blocked apoptosis induced by BIG-H3 is low (Zamilpa et.al.,2009). The current study investigated that when compared, EPDIM peptide with varying concentrations can induce apoptosis at a higher percentage than RGD in human osteosarcoma cells.