端粒酶活性在氯化镧诱导MDCC-MSB1细胞凋亡中的作用

探讨端粒酶活性在LaCl_3诱导MDCC-MSB1细胞凋亡中细胞中的作用.肿瘤细胞常规培养于RPMI1640培养液中,加入终浓度为3 mmol·L~(-1)的LaCl_3,继续培养12,24,36,48 h后,应用琼脂糖凝胶电泳和AO/EB双荧光染色检测细胞凋亡,以FITC-(C_3TA_2)_3 PNA为荧光探针检测细胞内端粒长度.以TRAP-PCR银染法检测端粒酶活性.LaCl_3浓度为3 mmol·L~(-1),作用0～48 h,细胞的琼脂精凝胶电泳和AO/EB双荧光染色法均观察到明显的细胞凋亡变化,细胞内端粒长度缩短,端粒酶活性下降,并呈时间-效应关系.LaCl_3可通过抑制MDCC-MSB1细胞端粒酶活性而诱导其发生凋亡.     

以G-四链体为靶点的小分子端粒酶抑制剂研究进展

富含鸟嘌呤碱基的DNA序列能够通过鸟嘌呤环的互联作用形成四链螺旋结构,这种结构被称为G-四链体。G-四链体由于能够抑制端粒酶的活性而成为抗肿瘤药物的新靶点,能促使G-四链体形成或稳定该结构的物质则可能对癌症有潜在的治疗意义。本文对以G-四链体为靶点的小分子端粒酶抑制剂的研究进行了综述。     

Impact of Arsenic Trioxide on LS-174T Cell Growth and the Activity of Telomerase

The therapeutic action of arsenic trioxide（ As203 ） on solid tumors has aroused widespread interest among scholars. To study the impact of As2O3 on human colorectal carcinoma cells（ LS-174T cell） and the activity of telomerase, the methods of PCR-ELISA, flow cytometry （FCM） and MTT assay in vitro were utilized. The results show that （1） with an increase in the concentration of As2O3, the ratio of living the cells to dead cells decreases significantly, and the IC50 value is 5.23 μg/mL; （2） the cells of the experimental groups can endure a series of morphological changes similar to the features of apoptosis ; （3） the apoptotic curves of FCM pictures appear after 24 h, and the cells show the apoptosis in a time-dependent manner; （4） As2O3 can inhibit the activity of telomerase of the cell extraction obviously in a concentration-dependent and time-dependent manner after 24 h. It can be concluded from the experiment results in vitro that As2O3 can induce the apoptosis of LS-174T cells and inhibit the telomerase activity. Therefore, it has been proposed, for the first time, that these two factors （the apoptosis of LS-174T cells and the inhibition to the telomerase activity） are important causes of the LS-174T cell death caused by As2O3.     

茜素/石墨烯-壳聚糖修饰玻碳电极应用于人类端粒DNA的测定

采用茜素(AR)掺杂石墨烯(CRG)、壳聚糖(CS)制备了AR/CRG-CS电极。该修饰电极在pH 7.4的PBS中出现了一对可逆的氧化还原峰,阳极峰的峰电位为"0.573 V,阴极峰峰电位为"0.652 V。通过循环伏安法(CV)证明AR在电极上发生了两电子两质子的氧化还原可逆过程,电子传递速率Ks为1.69 s"1。基于AR与人类端粒DNA相互作用导致的AR峰电流减弱及式量电位(E0’)负移的电化学信号,建立了一种灵敏简便、重现性好、稳定性好的测定人类端粒DNA的电化学方法,线性响应范围为8×10"8～1.4×10"5mol/L(R=0.9995),线性回归方程为Δi(μA)=8.4860+0.5366C(μmol/L),检出限为2×10"8mol/L(S/N=3)。