The aim of this study was to determine the effects and molecular mechanism of blue light emitting diode (LED) in tumor cells. A migration and invasion assay for the metastatic behavior of mouse colon cancer CT-26 and human fibrosarcoma HT-1080 cells was performed. Cancer cell migration-related proteins were identified by obtaining a 2-dimensional gel electrophoresis (2-DE) in total cellular protein profile of blue LED-irradiated cancer cells, followed by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis of proteins. Protein levels were examined by immunoblotting. Irradiation with blue LED inhibited CT-26 and HT-1080 cell migration and invasion. The anti-metastatic effects of blue LED irradiation were associated with inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 expression. P38 MAPK phosphorylation was increased in blue LED-irradiated CT-26 and HT-1080 cells, but was inhibited after pretreatment with SB203580, a specific inhibitor of p38 MAPK. Inhibition of p38 MAPK phosphorylation by SB203580 treatment increased number of migratory cancer cells in CT-26 and HT-1080 cells, indicating that blue LED irradiation inhibited cancer cell migration via phosphorylation of p38 MAPK. Additionally blue LED irradiation of mice injected with CT-26 cells expressing luciferase decreased early stage lung metastasis compared to untreated control mice. These results indicate that blue LED irradiation inhibits cancer cell migration and invasion in vitro and in vivo.
Strategies to promote angiogenesis can benefit cerebral ischemia. We determined whether liposomal delivery of angiogenic peptides with a known biologic activity of vascular endothelial growth factor benefitted cerebral ischemia. Also, the study examined the potential of 18 F-FDG PET imaging in ischemic stroke treatment. Methods: Male Sprague-Dawley rats (n 5 40) underwent 40 min of middle cerebral artery occlusion. After 15 min of reperfusion, the rats (n 5 10) received angiogenic peptides incorporated into liposomes. Animals receiving phosphate-buffered solution or liposomes without peptides served as controls. One week later, 18 F-FDG PET imaging was performed to examine regional changes in glucose utilization in response to the angiogenic therapy. The following day, 99m Tchexamethylpropyleneamine oxime autoradiography was performed to determine changes in cerebral perfusion after angiogenic therapy. Corresponding changes in angiogenic markers, including von Willebrand factor and angiopoietin-1 and -2, were determined by immunostaining and polymerase chain reaction analysis, respectively. Results: A 40-min period of middle cerebral artery occlusion decreased blood perfusion in the ipsilateral ischemic cortex of the brain, compared with that in the contralateral cortex, as measured by 99m Tchexamethylpropyleneamine oxime autoradiography. Liposomal delivery of angiogenic peptides to the ischemic hemisphere of the brain attenuated the cerebral perfusion defect compared with controls. Similarly, vascular density evidenced by von Willebrand factorpositive staining was increased in response to angiogenic therapy, compared with that of controls. This increase was accompanied by an early increase in angiopoietin-2 expression, a gene participating in angiogenesis. 18 F-FDG PET imaging measured at 7 d after treatment revealed that liposomal delivery of angiogenic peptides facilitated glucose utilization in the ipsilateral ischemic cortex of the brain, compared with that in the controls. Furthermore, the change in regional glucose utilization was correlated with the extent of improvement in cerebral perfusion (r 5 0.742, P 5 0.035). Conclusion: Liposomal delivery of angiogenic peptides benefits cerebral ischemia. 18 F-FDG PET imaging holds promise as an indicator of the effectiveness of angiogenic therapy in cerebral ischemia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.