The mechanism of lipid raft mediating chemoresistance of cervical cancer

OBJECTIVE: To investigate the mechanism of lipid raft mediating chemotherapy resistance in cervical cancer.

METHODS: This experiment was carried out in the Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from June 2010 to February 2011. Hela cells were divided into 6 groups: control group (Ctrl), cisplatin group (Cis), lipid raft interference agent group (MCD), NADPH oxidase inhibitor group (Apo), lipid raft interference agent combined with cisplatin group (MCD+Cis), and NADPH oxidase inhibitor combined with cisplatin group (Apo+Cis). After the cervical cancer cells were treated with a correspondent agent for 24 hours, the number of surviving cells were measured utilizing cell counting kits-8 (CCK-8), and the hypoxia inducible factor-1alpha (HIF-1alpha) levels were detected by Western blotting. Reactive oxygen species (ROS) levels were measured indirectly by detection of dichlorodihydrofluorescein fluorescence activity.

RESULTS: The cell growth of MCD slowed down (survival cells was 62% compared with the Ctrl group), with the Apo group showing a similar effect (65% in the control group), and 49% for the Cis group, MCD+Cis was 21%, and Apo+Cis was 23%. While the level of HIF-1alpha protein and ROS of the MCD group, Apo group, Cis group, MCD+Cis group and Apo+Cis group were decreased significantly compared to the control group. The level of HIF-1alpha of MCD group decreased by 69.9%, Apo group by 60.2%, Cis group was 55.5%, MCD+Cis group by 21.1% and Apo+Cis group by 25.4%, while the level of ROS also decreased in the MCD group by 38.6%, Apo group by 35.3%, Cis group by 24%, MCD+Cis group by 12.3% and Apo+Cis group by 12.8%.

CONCLUSION: Lipid raft may up-regulate ROS level and HIF-1alpha expression through activating NADPH oxidase, and thus promote chemotherapy resistance in cervical cancer.