[Ultrastructure of the tumor cell lines treated with tumor necrosis factor]

The cytotoxic effect of purified tumor necrosis factor (TNF) derived from rabbit treated with BCG-LPS on tumor cell lines was studied by electron microscopy. Tumor cell lines L929, CNE-2 (poorly-differentiated carcinoma of nasopharynx) and Pc84045 (adenocarcinoma of lung) were treated in vitro with TNF. It was found that the membrane of the target cells still remained intact, while the cytoplasmic organellae, especially the mitochondria were destroyed. The mechanism of TNF cytotoxic activity is discussed.