Calmodulin Inhibitor Decreases Cadmium Toxicity in Chinese Hamster Ovary Cells Synchronized at S Phase

• Main Authors: Wang Tsung Wei, 王琮瑋
• Other Authors: Lee Te Chang; Mrs. Tsuei Wen Huey
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/47485598811063617831

碩士 === 輔仁大學 === 生物學研究所 === 83 === Cadmium is very toxic to cells at S phase. In this report, the effects of cadmium on cytotoxicity and cell cycle progression in synchronous Chinese hamster ovary (CHO-K1) cells were studied. CHO- K1 cells were synchronized at G1/S boundary by serum starvation and aphidicolin arrest technique. Treatment of S phase cells with 2 μM cadmium for 8 h resulted in 98% of cell killing in the modes of apoptosis and necrosis. By bromodeoxyuridine labeling method, the progression of S phase cells toward G2 was dose dependently retarded by cadmium treatment. Cadmium and calcium ions share similar physical and chemical properties, and calcium-calmodulin complexes are important for physiological regulation of S phase cells. Therefore, we further investigate whether the toxic effects of cadmium is a consequence of deregulation of calmodulin function by cadmium binding. Our results have shown that trifluroperazine , a calmodulin inhibitor, was not only able to protect the cells from the killing effects of cadmium, but also moderate cadmium-induced retardation of cell cycle progression. The significant counteraction of trifluroperazine against cadmium's effects suggest that cadmium may exert its toxic effects through its improper activation of calmodulin.