The Initiatory Study Of Radiosensitization By Hyperbaric Oxygenon Nasopharyngeal Carcinoma

[Objective]To study the radiosensitization by HBO on human nasopharyngeal carcinom, and analysis the possible mechanisms of hyperbaric oxygen(HBO) to the radiotherapy of nasophryngeal carcinaoma.[Materials and Methods]The nasophryngeal carcinaoma CNE-2 cells were distributed randomly to six groups. One group was treated blankly as control group. Two group was radiated 2Gy only, Three group was only treated with 0.2MPa hyperbaric oxygen, Four group was only treated with 0.25MPa hyperbaric oxygen, Five group was radiated 2Gy rather after 0.2MPa hyperbaric oxygen, Six group was radiated 2Gy rather after 0.25MPa hyperbaric oxygen. 1,Examined the growth of CNE-2 and the cell cycle of CNE-2 under hyperbaric oxygen and radiotherapy with MTT method and flow cytometry.Flow cytometry was also used to analyze the change of the CNE-2 cell apoptosis.2,Established nude mice tumor models and observed the effects of HBO or combined with radiotherapy on the growth of tumor,calculated the tumor inhibitory ratio.3,Examined the expression of Ki67,Bax,EGFR in different group with immuohistochemistry. [Results]1,By MTT,compared with the control in which cells were not treated, six group cell growth were significantly inhibited. Inhibitory rate was 10.7%.Compared with two group, six group's inhibitory rate was higher(P<0.01).2,By flow cytometry, It was proved that the percentage of cells in G1 phase was different among the groups,and it was highest in HBO(0.25MPa)+radiotherapy group. And the apoptosis rate were highest than other groups.3,In six group, the volume inhibitory ratio and weight inhibitory ratio were different with other groups.The tumor inhibitory ratio in HBO+radiotherapy group was higher than radiotherapy or control group,4,The expression of Ki67 and EGFR in HBO+radiotherapy group was lower than radiotherapy or control group;but the expression of Bax in HBO+radiotherapy group was higher than radiotherapy or control group.[Conclusions]1,Hyperbaric oxygenation+radiotherapy suppresses the growth of CNE-2 cells and promotes the apoptosis of CNE-2 cells. this has been shown to a radiosensitizing effect on human nasopharyngeal carcinoma in vitro.2,Hyperbaric oxygenation +radiotherapy inhibited the growth of transplanted nude mice tumor this possibly has a association with the attenuated expression of Ki67 and EGFR and the enhancement expression of Bax. this has been shown to a radiosensitizing effect on human nasopharyngeal carcinoma in vivo.