抄録
Apoptosis is an important and well-controlled form of self-regulated cell death that differs from necrosit. This process has been recognized to be of major importance for embryonic development, tissue homeostasis, neurodegeneration, autoimmune disease, carcinogenesis, cancer progression, and the killing of cancer cells induced by chemotherapeutic drugs. Apoptosis is induced by radiation, heat, chemical agents, anticancer drugs, or some kinds of divalent metals. However, the effects of anticancer agents on cultured malignant cell lines are still obscure. The role of the anticancer drugs in induction of apoptosis in cultured malignant tumor cell lines also is not known. To investigate a possible relationship between anticancer reagents and apoptosis in oral malignant tumor cells, the effects of Carboplatin, Cisplatin, Mitomycin C, Peplomycin sulfate, and Doxorubicin hydrochloride on malignant tumor cell lines including human squamous carcinoma cell line, SCC-25 cells, human submandibular gland cell line, HSG cells, and human osteosarcoma cell line, Saos-2 cells were examined. Subconfluent cells were exposed to varying concentrations of these anticancer drugs. All the anticancer drugs used induced cell death in these cell lines in dose- and time-dependent fashions as determined by WST-1 assay and phase-contrast microscopy. By using the Hoechst 33342 staining, marked nuclear condensation and fragmentation of chromatin were observed in these cells treated with the anticancer agents. DNA ladder formation, a hallmark of apoptosis, also was detected in the anticancer drug-treated cells. The induced-DNA fragmentation and DNA ladder formation were dose and time dependent. The present results suggest the decreasing of tumor mass by the anticancer agents may be in part regulated by apoptosis.
