Inhibition of SENP5 suppresses cell growth and promotes apoptosis in osteosarcoma cells.

SUMOylation is a dynamic and reversible process. Several SUMO-specific proteases (SENPs) that remove SUMO from substrates have been shown to be amplified in a subset of cancers. SENP5 is required for cell division, as well as maintaining mitochondrial morphology and function. SENP5 has been reported to be predominantly localized to the cytoplasm of oral squamous cell carcinoma (OSCC) and is associated with the differentiation of OSCC. Western blot was used to detect the protein expression of SENP5 in osteosarcoma cells and tissue. Lentivirus-mediated siRNA was used to silence the expression of SENP5. Cell cycle distribution was determined by FACS analysis. The present study showed that SENP5 is overexpressed in osteosarcoma cells. In addition, lentivirus-mediated small interfering RNA (siRNA) of SENP5 significantly inhibited cell growth and induced apoptosis in osteosarcoma cells. SENP5 inhibition suppressed the growth and colony formation capacity of two osteosarcoma cell lines, U2OS and Saos-2. Silencing the expression of SENP5 in serum-starved U2OS and Saos-2 cells induced an increase in caspase-3/-7 activity and a decrease in cyclin B1 expression. These observations indicate that SENP5 is required for cell growth and apoptosis and may therefore be a promising drug target for antiosteosarcoma treatment.