Kumar C P, Pande G, Shanmugam G
Cancer Biology Division, School of Biological Sciences, Madurai Kamaraj University, Madurai-625 021, India.
Apoptosis. 1998 Dec;3(6):413-9. doi: 10.1023/a:1009658518998.
Cleistanthin B is a potential anticancer agent isolated from the tropical plant Cleistanthus collinus. We have previously shown that cleistanthin B is clastogenic and induces micronuclei formation and chromosomal aberrations. We now show that this compound inhibits DNA synthesis in Chinese hamster ovary (CHO) cells and induces apoptosis in cervical carcinoma (SiHa) cells. Flow cytometric analysis of cleistanthin treated CHO cells revealed that they were blocked in G1. Cervical carcinoma (SiHa) cells exposed to cleistanthin B shrank, rounded up and had condensed chromatin and fragmented nuclei. DNA isolated from cleistanthin treated cells exhibited the characteristic apoptotic ladder when electrophoresed in agarose gels. These results were confirmed by flow cytometry. Etoposide, a structurally similar compound also induced apoptosis in these cells although with a difference. Etoposide induced apoptosis after permitting cells to enter into S phase, while cleistanthin B stopped entry of cells into S phase and subsequently drove them to apoptosis.
克利斯坦丁B是从热带植物克利须那松中分离出的一种潜在抗癌剂。我们之前已经表明，克利斯坦丁B具有致断裂作用，可诱导微核形成和染色体畸变。我们现在表明，该化合物抑制中国仓鼠卵巢（CHO）细胞中的DNA合成，并诱导子宫颈癌（SiHa）细胞凋亡。对经克利斯坦丁处理的CHO细胞进行流式细胞术分析显示，它们停滞在G1期。暴露于克利斯坦丁B的子宫颈癌（SiHa）细胞会收缩、变圆，染色质浓缩，细胞核碎片化。从经克利斯坦丁处理的细胞中分离出的DNA在琼脂糖凝胶中电泳时呈现出典型的凋亡梯带。这些结果通过流式细胞术得到了证实。依托泊苷，一种结构相似的化合物，也能诱导这些细胞凋亡，不过存在差异。依托泊苷在允许细胞进入S期后诱导凋亡，而克利斯坦丁B则阻止细胞进入S期，随后促使它们凋亡。
