Dihydroartemisinin accentuates the anti-tumor effects of photodynamic therapy via inactivation of NF-κB in Eca109 and Ec9706 esophageal cancer cells.
BACKGROUND
Photodynamic therapy (PDT) is a new treatment for esophageal cancer which has been shown to be effective in the elimination of tumor. However, PDT could induce the activation of nuclear factor-kappa B (NF-κB) in many photosensitizers based PDT, which plays a negative role in PDT. In addition, our previous results have shown that dihydroartemisinin (DHA), which was the most potent one of artemisinin derivatives, has anticancer activity in esophageal cancer cells.


METHODS
Cell viability was determined by MTT analysis, and apoptosis was evaluated by flow cytometry. Nuclear extract was obtained for determining NF-κB DNA-binding activity, while total protein extract obtained for downstream gene expression by western blot.


RESULTS
We demonstrated DHA enhanced PDT-induced growth inhibition and apoptosis in both human esophageal cancer cell lines Eca109 and Ec9706 in vitro. The mechanism was at least partially due to DHA deactivated PDT-induced NF-κB activation, so as to decrease tremendously the expression of its target gene Bcl-2.


CONCLUSIONS
Our results demonstrate that DHA augments PDT-induced growth inhibition and apoptosis in esophageal cancer cells, and that inactivation of NF-κB activity is a potential mechanism by which DHA sensitizes esophageal cancer cells to PDT-induced growth inhibition and apoptosis.
Department of Gastrointestinal Oncology, The Third Affiliated Hospital, Harbin Medical University, Harbin, China.
Yan Jing
YJ
Li
Jian Hua
JH
Zhou
Xiao Xue
XX
Du
De Xin
de X
Jia
Chun Long
CL
Wu
Peng
P
Huang
Yu
Y
Han
Hong
H
Sui
Xiao Li
XL
Wei
Lei
L
Liu
Heng Heng
HH
Yuan
Ting Ting
TT
Zhang
Wen Jie
WJ
Zhang
Rui
R
Xie
Xiao Hui
XH
Lang
Tao
T
Liu
Cai Ling
CL
Jiang
Li Ying
LY
Wang
Yu Xian
YX
Bai
D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D037621:Artemisinins / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010778:Photochemotherapy; D013329:Structure-Activity Relationship
D000970:Antineoplastic Agents; D037621:Artemisinins; D016328:NF-kappa B; C039060:artenimol