RESUMO
With the further researches on the immune mechanisms in tumor,more and more scholars notice the phenomenon that radiation activates the immunity,and find that radiotherapy causes immunity suppression is one-sided.Although body's anti-tumor immunity can be enhanced by radiotherapy,in clinical,we observe that patients who receive radiotherapy cannot avoid tumor recurrence and metastasis.Researches show that tumor microenvironment makes the immune checkpoint pathway abnormally activated.Therefore,the combination of radiotherapy and immune checkpoint inhibitor can change the tumor microenvironment,and can improve the therapeutic effect.
RESUMO
OBJECTIVE: To observe the neuroprotective effect of Baicalein on H2O2-induced PC12 injury.METHODS: The PC12 cells cultured in vitro were preincubated with BAI for 24 h before being duplicated into the irreversible oxidative damages model with 500 ?mol?L-1 H2O2,then the protective effect of BAI (BAI presence or withdrawal) on these damaged cells in vitro was observed. The cell activity was detected by MTT microcolorimetry, and the lactate dehydrogenase(LDH) level in supernatant was determined as well. RESULTS: After pretreatment with BAI for 24 h,the injury of PC12 cells was significantly lessened in the presence or withdrawal of drugs in modeling, especially in the presence of drugs. Microscopically, PC12 cells can be seen with fuzzy edge and increased size, and cell fusion occurred in the BAI-treated H2O2 injury model. Cell activity increased,LDH level in the medium decreased, which were significantly different as compared with the model group. CONCLUSION: BAI can significantly reduce the hypoxic-ischemic injury of PC12 cells. Its mechanism may be related to its ability in reducing the accumulation of free radicals induced by blockage of the respiratory chain, antioxidation and free radical scavenging.