Recent work demonstrates that GSK-3 beta is involved in the process of tumorigenesis, and inhibition of the expression and activity of GSK-3 beta attenuates cell proliferation and causes apoptosis in colorectal, pancreatic and ovarian cancer cells. Lithium is an existing drug for psychiatric diseases and its uptake has been linked to reduced tumor incidence compared to the general population, furthermore, lithium has been shown to be a specific and noncompetitive inhibitor of GSK-3 beta activity in vitro and in vivo. Recent researches have proved that lithium could promote or inhibit cell cycle transition and proliferation of certain primary cultures or cell lines by inhibiting GSK-3 beta , depending on the cell type. However, whether lithium influences the growth and proliferation of esophageal cancer cells remains unknown to date.
A research article published on 7 July 2008, in the World Journal of Gastroenterology demonstrates for the first time that lithium inhibited the proliferation of esophageal squamous cell carcinoma cells (Eca-109), which was mainly mediated by the inhibition of GSK-3 beta and reduction of cyclin B1 expression.
The authors demonstrated for the first time that lithium inhibited the proliferation of Eca-109 estimated by MTT assay and induce G2/M cell cycle arrest, which was mainly mediated by the inhibition of GSK-3beta and reduction of cyclin B1 expression. Lithium is an existing drug for psychiatric diseases and its uptake has been linked to reduced tumor incidence compared to the general population. Since the major target of lithium action has been shown to be GSK-3beta, the purpose of this study is reasonable and results are clearly demonstrated. Although further studies are required, this study indicates the novel possibility for the treatment of the esophageal squamous cell carcinoma with lithium cloride.