IMBICE, Instituto Multidisciplinario de Biología Celular, La Plata, Argentina.
Mutat Res. 2009 Nov 2;670(1-2):99-102. doi: 10.1016/j.mrfmmm.2009.07.009. Epub 2009 Jul 29.
Mitochondrial DNA 4977-bp deletion (common deletion) has been associated with ageing human tissues and a few studies have demonstrated their presence in breast cancer patients too; however, no previous publication evaluated both topics in the same samples group. First, when analyzing 95 breast cancer patients, we found a higher percentage of cases carrying the deletion in non-tumoral tissue 73.68% (70/95) than in the tumoral counterparts 45.26% (43/95), showing that the 4977-bp deletion is a phenomenon which commonly appear first in the non-tumoral breast tissue rather than tumoral tissue. Secondly, we analyzed and compared the ageing related distribution of the common deletion rates, in a control group of 199 samples (ages ranging from 10 to 80 years), with those found in cancer patients. Significant correlation was observed in control cases, between individual age ranges and rates of deletion (chi2: 23.21 and p<0.01). In contrast, non-tumoral breast tissue did not show a pattern of correlation, chi2: 0.042 and p: 0.837. However, interestingly, we found that the risk of having deleted mtDNAs was higher for non-tumoral breast samples than for the control group samples, OR: 2.32 [1.22-4.42, 95% CI]; this could be reflecting that other mechanisms are involved in mitochondrial genome deletion increased rate detected in breast cancer cases, than the normal ageing process.
线粒体 DNA 4977 位碱基缺失（常见缺失）与人类衰老组织有关，一些研究也表明其存在于乳腺癌患者中；然而，以前没有研究在同一组样本中同时评估这两个主题。首先，在分析 95 例乳腺癌患者时，我们发现非肿瘤组织中携带缺失的病例比例较高，为 73.68%（70/95），而肿瘤组织中携带缺失的病例比例为 45.26%（43/95），这表明 4977 位碱基缺失是一种常见现象，首先出现在非肿瘤性乳腺组织中，而不是肿瘤性组织中。其次，我们分析并比较了对照组 199 例样本（年龄范围为 10 至 80 岁）中与癌症患者相同的常见缺失率的与年龄相关的分布。在对照组中，个体年龄范围与缺失率之间存在显著相关性（chi2：23.21，p<0.01）。相比之下，非肿瘤性乳腺组织中缺失率没有表现出相关性，chi2：0.042，p：0.837。然而，有趣的是，我们发现非肿瘤性乳腺组织中缺失 mtDNA 的风险高于对照组样本，OR：2.32 [1.22-4.42，95%CI]；这可能反映了在乳腺癌病例中检测到的线粒体基因组缺失率增加的其他机制，而不是正常的衰老过程。
