ABSTRACT
The purpose of this study is to further explore the effects of SI-4650, a newly discovered small molecule inhibitor of spermine oxidase (SMO) in our laboratory, on proliferation and migration of human osteosarcoma 143B cells and its underlying molecular mechanism. Chemiluminescence and high performance liquid chromatograph were used to analyze the effect of SI-4650 on SMO activity in 143B cells. DCFH-DA-staining/FCM was used to analyze the accumulation of cellular reactive oxygen species (ROS), whereas MTT and FCM were used to detect proliferation and cell cycle. Transwell culture and Western blot were used to analyze the expression levels of migration-related proteins. PI/FITC-Annexin V/FCM, fluorescence microscopy and Western blot were used to analyze apoptosis and autophagy. Our results showed that SI-4650 could significantly decrease SMO activity, inhibit cell proliferation or migration, and induce a S-phase cell cycle arrest in 143B human osteosarcoma cells. The mechanism may be related to interfering with polyamine metabolism, activating mitochondrial-mediated apoptosis and causing autophagic death. These results suggest that SI-4650 has the potential for clinical use in treatment of osteosarcoma.
ABSTRACT
AIM@#To identify the glucose lowering ability and chronic treatment effects of a novel coumarin-glucagon-like peptide-1 (GLP-1) conjugate HJ07.@*METHOD@#A receptor activation experiment was performed in HEK 293 cells and the glucose lowering ability was evaluated with hypoglycemic duration and glucose stabilizing tests. Chronic treatment was performed by daily injection of exendin-4, saline, and HJ07. Body weight and HbA1c were measured every week, and an intraperitoneal glucose tolerance test was performed before treatment and after treatment.@*RESULTS@#HJ07 showed well-preserved receptor activation efficacy. The hypoglycemic duration test showed that HJ07 possessed a long-acting, glucose-lowering effect and the glucose stabilizing test showed that the antihyperglycemic activity of HJ07 was still evident at a predetermined time (12 h) prior to the glucose challenge (0 h). The long time glucose-lowering effect of HJ07 was better than native GLP-1 and exendin-4. Furthermore, once daily injection of HJ07 to db/db mice achieved long-term beneficial effects on HbA1c lowering and glucose tolerance.@*CONCLUSION@#The biological activity results of HJ07 suggest that HJ07 is a potential long-acting agent for the treatment of type 2 diabetes.