Effects of Nocodazole on Protein Synthesis Appratus of Tumor Cells

Kim, Sun Hee; Kim, Joo Young; Sung, Eon Gee; Lee, Yun Chanl

Abstract

Nocodazole is an anticancer agent that acts on microtubules or filaments. HeLa, Hep G2, A549, L929 and NIH/3T3 cell lines were cultivated in alpha-MEM with 3micrometer or 30micrometer nocodazole. To elucidate the associations between nocodazole`s antitumor actions and these effects, the influences of nocodazole on the cellular morphology and the organelles involving synthesis, secretion and destruction of proteins were investigated under light and electron microscopes. The changes of intermediate filaments such as pancytokeratins and vimentins that maybe suggest antimetastatic action of nocodazole were observed using immunocytochemical technique, PAP at light microscopic level. Rounded or micronucleate cells were induced by treatment with 3micrometer and 30micrometer nocodazole for 2 hours to 4 days. Multimicronucleate cells appeared in experimental groups of all cell lines. Nuclear foldings occurred in cells of experimental groups treated with nocodazole for 2-3 days. The numerical increases of rough endoplasmic reticulum were observed in HeLa cells treated with nocodazole for 3 days and the dilatation or numerical increases in L929 cells treated with nofodazole for 1-3 days. The fragmentations or dispersion of Golgi complex were observed in cells treated with nocodazole for 1-3 days. The amount of filaments increased in cells treated with nocodazole for 1-3 days. The number of lysosomes increased in cells treated with nocodazole for 1-3 days. The number of liposomes also increased in Hep G2 cells treated with 30micrometer nocodazole for 3 days and in 3micrometer & 30micrometer, 3 days group of 3T3 cells. The amount of pancytokeratins and vimentins increased in cells treated with nocodazole for 1-3 days. Taken together, depolymerization of microlubules was induced by nocodazole, and then the organization of cells was disintegrated. As a result, the rounded cells, the cells having multimicronuclei, and the changes of golgi complexes occurred. But there were relatively no great changes of rough endoplasmic reticulum. The amount of intermediate filaments that maintain the differentiated states of cells increased by nocodazole treatment. It was suggested that morphological changes of cells could be used in evaluation of actions of nocodazole. Especially, the increase of amount of intermediate filaments by nocodazole changed cells of each cell line from undifferentiated state to differentiated, and therefore the author hope that the changes in amount of intermediate filaments provide an important clue in anticancer and antimetastatic actions of nocodazole.