Abstracts
1998 Digestive Disease Week
#965
THE P21 CYCLIN-DEPENDENT KINASE PROTECTS ESOPHAGEAL CARCINOMA CELLS FROM RADIATION. D.A. Rigberg, F.S. Kim, T.A. Blinman, J. So, D.W. McFadden, Dept of Surgery, UCLA, Los Angeles, CA.
The p21 cyclin-dependent kinase inhibitor arrests the cell cycle in response to DNA damage, but its role in apoptosis following such injury is unclear. Previous studies have demonstrated that p21 may either prolong or diminish survival depending on specific cell type. The aim of this study was to determine if p21 mRNA blockade would affect esophageal squamous cell carcinoma (ESCC) survival following irradiation.
METHODS: The ESCC line KYSE 150 was transiently transfected with either antisense p21 mRNA oligonucleotides or 20-mer p21 control oligonucleotides using a lipofectant reagent. Cells were then exposed to 6 Gy doses of radiation or used as controls. Total protein was extracted from some cells, and p21 levels determined via ELISA. Other cells were allowed to grow for 7 days, at which time clonogenic survival was determined via Coulter machine. Student's t-test was used to compare survival and protein levels.
RESULTS: Mean ± SEM, *p<0.05 vs. controls
CONCLUSIONS: p21 protein levels fell following transfection of the KYSE 150 cells. In addition, transfected cells demonstrated decreased survival when exposed to radiation. This study suggests that p21 protein offers a survival advantage to KYSE 150 cells following radiation-induced DNA damage, possibly by allowing DNA repair during cell-cycle arrest.
Copyright 1996 - 1998, SSAT, Inc. Revised 29 June 1998.
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