Tsutomu Uchida

Publications (2)6.65 Total impact

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

  Katsunao Nakagami, Tsutomu Uchida, Susumu Ohwada, Yukio Koibuchi, Yasuo Morishita
  [show abstract] [hide abstract]
  ABSTRACT: 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 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 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 gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation.
  Cancer Science 10/1999; 90(11):1212 - 1217. · 3.33 Impact Factor
• Article: Increased Choline Kinase Activity and Elevated Phosphocholine Levels in Human Colon Cancer†

  Katsunao Nakagami, Tsutomu Uchida, Susumu Ohwada, Yukio Koibuchi, Yasuo Suda, Takeshi Sekine, Yasuo Morishita
  [show abstract] [hide abstract]
  ABSTRACT: Nuclear magnetic resonance spectroscopy has detected elevated phosphocholine levels in human tumor tissues and cells, and in cells that were transformed with the activated Ha-ras gene and stimulated in vitro with growth-promoting factors such as platelet-derived growth factor, epidermal growth factor, and phorbol ester. However, the mechanism of the elevation and the function of the increased phosphocholine levels have not been clearly demonstrated. We studied phosphocholine levels enzymatically and analyzed the activity of choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in human colon cancer and adenoma. Both choline kinase activity and phosphocholine levels were increased in colon cancer and adenoma tissue. The activation of choline kinase and the increased levels of choline kinase α were partly responsible for the elevated phosphocholine levels. This study suggests that choline kinase might play a role in growth promotion or signal transduction in carcinogenesis.
  Cancer Science 03/1999; 90(4):419 - 424. · 3.33 Impact Factor