Effects of inactivation of vitamin D receptor in intestinal tumor growth of APCmin/+ mice

Abstract

Objective To explore effects and mechanism of inactivation of vitamin D receptor (VDR) in intestinal tumor growth of APCmin/+ mice. Methods To generate APCmin/+VDR -/- mice through breeding, the number and size of small intestinal and colonic tumors were assessed and compared between APCmin/+ and APCmin/+ VDR -/- mice. The intestinal tumors were diagnosed with HE stain. The expressions of BCL-2,vimentin-1,Stat-1 and MSH-2 proteins of tumors were determined by immanohistocbemistry and compared be-tween APCmin/+ and APCmin/+VDR -/- mice. Results A comparison between APCmin/+ and APCmin/+ VDR -/- mice revealed that the number of the tumors, which were larger than 3mm, was significantly increased in APCmin/+ VDR -/- mice at 4 months of age (P< 0.01). HE staining indicated fistulous adenomas from small intestine and colon of two groups, Immunostaining showed Stat - 1 level in APC-min/+ tumors were increased and MSH-2 and vimentin-1 levels in APCmin/+ VDR-/- mice were increased, compared to APCmin/+tumors. Conclusion These observations suggested that inactivation of VDR promoted the intestinal tumor growth of APCmin/+ mice. Key words: Intestinal neoplasms/GE; Receptors; calcitrioL/BI; Genes; bcl-2/BI; Intermediate filament proteins/BI; Proto-onco-gene proteins/Bl