Silencing hexokinase II gene sensitizes human colon cancer cells to 5-fluorouracil.
OBJECTIVE
Extensive trials have indicated that cancer cells with high glycolytic activity exhibit decreased sensitivity to anticancer agents. Moreover, recent research has proved that a specific inhibitor of hexokinase II, which is a key glycolytic enzyme, may enhance the activity of anticancer drugs. The purpose of this study is to further investigate the effect and mechanisms of hexokinase II on chemosensitivity of colon cancer cells to 5-fluorouracil.


METHODS
The expression of hexokinase II gene was down regulated by RNA interference in colon cancer cell line LoVo, then the IC50 value of 5-fluorouracil to LoVo cells was carried out by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and the protein expression of hexokinase II and thymidylate synthas by Western blot analysis Meanwhile, cell apoptosis and mitochondrial membrane potential were assessed by flow cytometry. Caspase-3 activity was also determined by its substrate color reaction.


RESULTS
Down-regulation of the hexokinase II gene of LoVo cells resulted in decreased IC50 value of 5-fluorouracil and increased apoptosis rate, respectively. Furthermore, silencing hexokinase II of LoVo cells induced loss of mitochondrial membrane potential, activation of caspase-3, and inhibition of thymidylate synthase expression.


CONCLUSIONS
Our findings suggest targeting hexokinase II has a potential role in the combination 5-fluorouracil treatments of colon cancer.
Peng
Qiuping
Q
Department of Oncology, Southwest Hospital, The Third Military Medical University Chongqing 400038, PR China.
Zhou
Jinming
J
Zhou
Qi
Q
Pan
Feng
F
Zhong
Daping
D
Liang
Houjie
H
D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology*; D015536:Down-Regulation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005472:Fluorouracil / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing / Q000187:drug effects*; D006593:Hexokinase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000235:genetics; D034622:RNA Interference / Q000187:drug effects; D013940:Thymidylate Synthase / Q000378:metabolism; D014162:Transfection
D013940:Thymidylate Synthase; D006593:Hexokinase; D053148:Caspase 3; D005472:Fluorouracil