Abstract: Objective:To investigate the protection effect and mechanism of slug overexpression on irradiation of rat intestinal epithelial cells . Methods: The study are the intestinal crypt epithelial cells (IEC6) and the IEC6 transfected with Slug cDNA in vitro.The cells are irradiated with 6 Gy60Co gamma rays.48 hours after the irradiation, Apoptosis indexes are calculated.The expression of PUMA are observed by the Immunohistochemistry and Western-blot.Result: The apoptosis indexes in IEC6 by the irradiation of 60Co gamma rays after 48 hours is significantly higher than in pcDNA3-Slug cDNA and in pcDNA3-Slug cDNA without irradiation(15.6+1.54 versus 5.1+1.7; 2.21+0.36; P<0.01). The expression of PUMA in IEC6 by the irradiation of 60Co gamma rays after 48 hours is significantly higher than in pcDNA3-Slug cDNA by Western-blot (0.79+0.12 versus 0.16+0.01; P<0.01). The Immunohistochemistry and Weatern blot assay results are consistent.Conclusions: Upregulation of Slug can restrain the upregulation expression of PUMA in irradiated cells and the apoptosis of IEC6.

Key words: Slug, PUMA, Ray irradiation, Apoptosis, Rat intestinal epithelial cells