Increased Choline Kinase Activity in 1,2‐Dimethylhydrazine‐induced Rat Colon Cancer

Cancer cells acquire particular characteristics that benefit their proliferation. We previously reported that human colon cancers examined had increased choline kinase activity and phospho‐choline levels. The elevated phosphocholine levels were in part due to both activation of choline kinase and increased choline kinase α protein levels. In this report, we analyzed choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in rat 1,2‐dimethylhy‐drazine (DMH)‐induced colon cancer. This study is the first to demonstrate increased choline kinase α enzymatic activity, protein levels, and mRNA levels in DMH‐induced colon cancer as well as human colon cancer, although phosphocholine was not increased in DMH‐induced rat cancer. The increase in the mRNA level was partly due to an increase in the transcription of the choline kinase α gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation.