Effects of alpha-difluoromethylornithine-induced polyamine depletion on the radiosensitivity of a human colon carcinoma cell line.

Abstract

The effect of the polyamine biosynthesis inhibitor alpha-difluoromethylornithine (DFMO) on the in vitro radiation response of Clone A human colon adenocarcinoma cells was investigated. Analysis of intracellular polyamine levels showed that exposure of Clone A cells to 1 mM DFMO for 96 h reduced putrescine and spermidine to nondetectable levels, while spermine was decreased by approximately 50%. This DFMO treatment protocol enhanced the radiosensitivity of Clone A cells, which was reflected by a decrease in both the Do and Dq. The addition of putrescine (1 mM) for the final 48 h of DFMO exposure restored polyamine levels and returned clone A radiosensitivity to that of control cells. These results indicate that polyamine depletion by DFMO sensitizes Clone A tumor cells to ionizing radiation.

• Authors: C M Arundel, K Nishioka, P J Tofilon
• Journal: Radiation research (Radiat Res) Vol. 114 Issue 3 Pg. 634-40 (Jun 1988) ISSN: 0033-7587 [Print] United States
• PMID: 3131831 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Cesium Radioisotopes
• Polyamines
• Eflornithine

Topics

• Cell Line
• Cell Survival (drug effects, radiation effects)
• Cesium Radioisotopes
• Colonic Neoplasms (pathology)
• Eflornithine (pharmacology)
• Gamma Rays
• Humans
• Polyamines (biosynthesis)
• Radiation Tolerance
• Tumor Cells, Cultured (drug effects, radiation effects)