苦参碱对人髓母细胞瘤D341细胞凋亡及相关蛋白表达的影响*

 目的：  探讨苦参碱在体外对人髓母细胞瘤D341细胞凋亡及Bax、Bcl-2、丝氨酸/苏氨酸激酶Akt和磷酸化Akt（p-Akt）表达的影响。方法: 体外培养的D341细胞分为实验组（加不同浓度的苦参碱）和对照组（不加苦参碱），用CCK-8法检测苦参碱对D341细胞增殖的影响，Annexin V-FITC/PI双染法检测细胞凋亡，Western blotting检测苦参碱对D341细胞Bax、Bcl-2、Akt和p-Akt蛋白表达的影响。结果: 苦参碱在体外能明显地抑制D341细胞的生长，作用呈量效与时效关系；随着作用药物浓度的增高和作用时间的延长，其凋亡率逐渐升高，在透射电镜下观察，细胞可见染色质趋边固缩，胞浆中空泡增多、变大，并且出现凋亡小体；Western blotting结果表明，随着药物浓度的增加，药物能使瘤细胞Bax蛋白的表达水平增强，却使Bcl-2和p-Akt蛋白的表达水平下降。结论: 苦参碱可诱导D341细胞的凋亡而发挥体外抗肿瘤作用，其诱导瘤细胞的凋亡与上调Bax蛋白、下调Bcl-2及PI3K /Akt 信号通路中p-Akt蛋白的表达水平有关。

Effects of matrine on apoptosis and related protein expression in human medulloblastoma D341 cells

AIM: To investigate matrine-induced apoptosis of human medulloblastoma D341 cells and the expression of Bax, Bcl-2, serine/threonine kinase Akt and phosphorylated Akt (p-Akt) in vitro. METHODS: D341 cells were divided into experimental groups (added with matrine at different concentrations) and control group (under the same conditions without matrine). The proliferation of D341 cells was analyzed by CCK-8 assay. Apoptosis was detected by Annexin V-FITC/PI double staining and the expression of Bax, Bcl-2, Akt and p-Akt was detected by Western blotting. RESULTS: Matrine significantly inhibited the proliferation of D341 cells and increased the apoptosis in a dose- and time-dependent manner. The cell apoptosis was characterized by chromatin condensation with margination of chromatin to the nuclear membrane, increased when and larger cytoplasmic vacuoles, and formation of apoptotic body after treatment with matrine. The expression of Bax increased, while the expression of Bcl-2 and p-Akt decreased when the drug concentration gradually increased. CONCLUSION: Matrine induces the apoptosis of human medulloblastoma D341 cells in vitro by activation of Bax, down-regulation of Bcl-2 and reduction of p-Akt expression level in the PI3K/Akt signaling pathway.