Study of Capsaicin-induced Apoptosis in Human Colon Cancer Cell Lines

PURPOSE: Numerous investigations have been conducted in order to determine the potential carcinogenic or chemopreventive activity of capsaicin. The aim of this study is to characterize the effects of capsaicin on colon cancer cells, and provide valuable information concerning the application of capsaicin in chemoprevention as well as for therapeutic purposes. METHODS: CoLo320DM and LoVo cells (human colon cancer cell line) were treated with capsaicin. In order to access cell viability and altered morphology, an MTT assay was performed and the cells were microscopically examined. Decreasing DNA staining was accessed by FACS. The cells were stained with FITC labeled annexin V and analyzed by FACS to detect cellular membrane alteration during apoptosis. The cells were stained with DiOC6(3) and Hydroethidine and analyzed by FACS in order to access ROS and dleta psi m. RESULTS: Capsaicin decreased cell viability in a dose-dependent manner. Capsaicin produced a cell morphology corresponding to the apoptotic features including cell shrinkage and chromatic condensation. Capsaicin treated cells induced a loss of nuclear DNA leading to hypoploidy in a dose-dependent manner. Cells were excluded by double staining with PI and FITC labeled annexin v and detected by FACS. We show that treatment of CoLo320DM, L0Vo cells with increasing concentrations of capsaicin parallel an increase in the percentage of red fluorescent cells (HE-->Eth) that reflect ROS hypergeneration and a decrease in the percentage of green fluorescent cells that reflect delta psi m disruption. CONCLUSION: These results clearly demonstrate that capsaicin-induced colon cancer cell death is apoptotic.

Expression of a Novel 90 kDa Heat Shock Protein in Colorectal Tumor

PURPOSE: When cells are subjected to a wide variety of stressful stimuli, they respond by increasing the synthesis of specific stress proteins. Stresses include heat shock, nutrient deprivation, oxygen radicals, toxic metal and viral infection. Major stress proteins are Hsp 27, Hsp 60, Hsp 70 (9), Hsp 90 (3) and Hsp 100 (1). Previously a novel 90 kDa stress protein has been reported to be induced in fish cells by virus infection. The novel 90 kDa stress protein is different from well-known major stress protein in size, antigenicity, cellular localization. The novel 90 kDa stress protein was found to be present in various kinds of cells including human cells and its expression was increased in human carcinomas. The purpose of this study is to evaluate the expression of the novel 90 kDa stress protein in human colonic mucosa of normal tissue, adenoma and adenocarcinoma using immunohistochemical method. METHODS: 85 colon tissues were screened for the expression of the novel 90 kDa stress protein; 85 normal colonic mucosa, 20 colonic adenoma and 65 colonic adenocarcinoma. The tissues were stained with monoclonal antibody against the novel 90 kDa stress protein. In scoring system, tissue sections with immunostained area above 10 % were decided to be positive and, among the positive, the tissue sections were divided into three score, 1, 2, and 3, based on the staining intensity and positive area proportion. The tissue sections with immunostained area below 10% were decided to be negative and grouped into 0 score. Correlation of immunohistochemical expression was analysed by using SPSS version 10.0 statistically. RESULTS: The expression of the 90 kDa stress protein was significantly different among normal colonic mucosa, colonic adenoma, and colonic adenocarcinoma and the percentage of positive samples were 14.1%, 80.5%, and 95.4% respectively. This result suggests that the expression level of the novel 90 kDa stress protein was extremely low in normal tissue but increased significantly in adenocarcinomatous tissues. CONCLUSIONS: The expression of the novel 90 kDa stress protein was increased significantly with transformation of the normal colon tissue to malignancy. This suggests the possibility that this novel 90 kDa stress protein play some role in cancerous transformation of colon tissue.