Diallyl disulfide inhibits p34(cdc2) kinase activity through changes in complex formation and phosphorylation
1Graduate Program in Nutrition and the Nutrition Department, 126 Henderson Building South, The Pennsylvania State University, University Park, PA 16802, USA.
Carcinogenesis
|June 3, 2000
Summary
Diallyl disulfide (DADS) from garlic suppresses colon tumor cell growth by inhibiting p34(cdc2) kinase activity. DADS affects cyclin B(1) and cdc25C protein levels, leading to cell cycle arrest.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Diallyl disulfide (DADS), a compound in garlic, has previously shown to inhibit p34(cdc2) kinase activity and induce G(2)/M phase arrest in human colon tumor cells.
- The precise mechanism by which DADS suppresses p34(cdc2) kinase activity requires further elucidation.
Purpose of the Study:
- To investigate the molecular mechanisms underlying DADS-induced G(2)/M phase arrest in colon tumor cells.
- To determine if DADS directly interacts with p34(cdc2) or affects regulatory factors.
Main Methods:
- Flow cytometry was used to analyze cell cycle distribution and cyclin B(1) protein expression.
- Western blot analysis was employed to assess p34(cdc2) protein levels, p34(cdc2)/cyclin B(1) complex formation, p34(cdc2) hyperphosphorylation, and cdc25C protein expression.
Main Results:
- DADS treatment led to an increase in cyclin B(1) protein expression in a dose- and time-dependent manner.
- DADS decreased the association of p34(cdc2) with cyclin B(1) and caused modest p34(cdc2) hyperphosphorylation.
- DADS reduced cdc25C protein expression, correlating with increased p34(cdc2) hyperphosphorylation.
Conclusions:
- DADS inhibits p34(cdc2) kinase activation not through direct interaction, but by altering regulatory factors.
- Decreased p34(cdc2)/cyclin B(1) complex formation and enhanced p34(cdc2) hyperphosphorylation are key mechanisms for DADS's anti-cancer effect.
- These findings highlight DADS as a potential therapeutic agent in colon cancer treatment.
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