Screening and preliminary research of an actinomyces strain with antitumor effect
在经过MTT法初筛得到的具有细胞毒的海洋微生物中 ,我们又采用荧光显微观测法 ,发现放线菌AK 1 1处理的细胞发生凋亡。在琼脂糖电泳上呈现DNA梯度带 ,进一步验证了其具有使细胞凋亡的作用。AK 1 1活性化合物纯品的裸鼠试验结果表明 :其试验浓度为 0 .0 1 6 μg·kg- 1,0 .1mL/次和 0 .0 0 8μg·kg- 1,0 .1mL/次时抑瘤率分别为 5 2 .0 %和 33.6 %。对人胃癌细胞MGC 80 3及人胃肝细胞SMMC772 1的IC50 的测定值略小于阿霉素 ,显示了AK 1 1具有较高的抗肿瘤活性。FCM对细胞周期的分析表明 :经AK 1 1处理后细胞在S期发生阻滞。DNA合成受阻The apoptosis was observed under a fluoroscope when the tested tumor cells were treated with the supernatant derived from the liquid culture of an actinomyces strain AK 11, which had showed cell toxicity by means of MTT assay, and was further confirmed by the correspondent band of ”DNA ladder” in the agarose gel electrophoresis. In a bioassay employed nude mouse, the pure compound produced by the strain AK 11 showed tumor inhibition in rates of 52.01% and 33.64% corresponding to the dosages of 0.016 μg·kg -1 and 0.008 μg·kg -1 ip, respectively. According to the indexes IC 50 of human hepatocarcinoma SMMC7721 and stomach cancer MGC 803 cells, it was estimated that the inhibition effect of the pure compound was slightly stronger than that of Adriamycin. The results showed high antitumor effect of the tested compound from the strain AK 11. When the cells were treated with AK 11, it was found by flow cytometry analysis that cell division was ceased at S phase due to the DNA synthesis block .