Role of calcium in the regulation of ornithine decarboxylase enzyme activity in mouse colon cancer cells

Jin Ishizuka, Richard J. Bold, Courtney M. Townsend, James C. Thompson

Research output: Contribution to journalArticle

3 Scopus citations


Activity of ornithine decarboxylase (ODC), one of the rate-limiting enzymes in the pathway of polyamine biosynthesis, is regulated by various factors. In this study, we examined the role of Ca2+ in the regulation of ODC enzyme activity in mouse colon cancer cells (MC-26). KCl, a membrane-depolarizing agent that opens the voltage-dependent Ca -channel to increase intracellular Ca2+, decreased serum-induced ODC enzyme activity in MC-26 cells in a dose-dependent, reversible fashion. Both verapamil and nifedipine, inhibitors of the L-type voltage-dependent Ca2+-channel, decreased serum-induced ODC enzyme activity. W-7, a calmodulin inhibitor, decreased ODC enzyme activity in a dose-dependent, reversible fashion while trifluoperazine, another calmodulin inhibitor, failed to affect ODC enzyme activity in MC-26 cells. Our findings indicate that intracellular Ca participates in the regulatory mechanism of ODC enzyme activity in MC-26 cells, although the exact role of Ca2+ is still unclear.

Original languageEnglish (US)
Pages (from-to)181-187
Number of pages7
JournalCancer Investigation
Issue number2
StatePublished - Jan 1 1995


ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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