Paviolo Natalia S, Santiñaque Federico F, Castrogiovanni Daniel C, Folle Gustavo A, Bolzán Alejandro D
Laboratorio de Citogenética y Mutagénesis, Instituto Multidisciplinario de Biología Celular (IMBICE, CCT-CONICET La Plata-CICPBA), C.C. 403, CP 1900 La Plata, Argentina.
Servicio de Citometría de Flujo y Clasificación Celular (SECIF), Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av. Italia 3318, CP 11600 Montevideo, Uruguay.
Mutat Res Genet Toxicol Environ Mutagen. 2015 Dec;794:17-24. doi: 10.1016/j.mrgentox.2015.09.007. Epub 2015 Oct 1.
We analyzed chromosomal aberrations involving telomeres in the progeny of mammalian cells exposed to the methylating agent and antineoplastic/diabetogenic drug streptozotocin (STZ), to test whether it induces long-term telomere instability (by chromosome end loss and/or telomere dysfunction). Rat cells (ADIPO-P2 cell line, derived from Sprague-Dawley rat adipose cells) were treated with a single concentration of STZ (2mM). Chromosomal aberrations were analyzed 18h, 10 days, and 15 days after treatment, using PNA-FISH with a pan-telomeric probe [Cy3-(CCCTAA)3] to detect (TTAGGG)n repeats. Cytogenetic analysis revealed a higher frequency of chromosomal aberrations in STZ-exposed cultures vs. untreated cultures at each time point analyzed. The yield of induced aberrations was very similar at each time point. Induction of aberrations not involving telomere dysfunction was only observed 18h and 15 days after treatment, whereas induction of telomere dysfunction-related aberrations by STZ (mainly in the form of telomere FISH signal loss and duplications, most of them chromatid-type aberrations) was observed at each time point. Our results show that STZ induces persistent telomere instability in mammalian cells, cytogenetically manifested as telomere dysfunction-related chromosomal aberrations. Neither telomere length nor telomerase activity is related to the telomere dysfunction.
我们分析了暴露于甲基化剂及抗肿瘤/致糖尿病药物链脲佐菌素（STZ）的哺乳动物细胞后代中涉及端粒的染色体畸变，以测试其是否会诱导长期的端粒不稳定性（通过染色体末端缺失和/或端粒功能障碍）。用单一浓度的STZ（2mM）处理大鼠细胞（ADIPO-P2细胞系，源自Sprague-Dawley大鼠脂肪细胞）。在处理后18小时、10天和15天，使用带有泛端粒探针[Cy3-(CCCTAA)3]的肽核酸荧光原位杂交（PNA-FISH）分析染色体畸变，以检测（TTAGGG）n重复序列。细胞遗传学分析显示，在每个分析的时间点，与未处理的培养物相比，暴露于STZ的培养物中染色体畸变的频率更高。在每个时间点，诱导畸变的发生率非常相似。仅在处理后18小时和15天观察到不涉及端粒功能障碍的畸变诱导，而在每个时间点均观察到STZ诱导的与端粒功能障碍相关的畸变（主要表现为端粒FISH信号缺失和重复，其中大多数为染色单体型畸变）。我们的结果表明，STZ在哺乳动物细胞中诱导持续的端粒不稳定性，细胞遗传学上表现为与端粒功能障碍相关的染色体畸变。端粒长度和端粒酶活性均与端粒功能障碍无关。
